Commit Graph

4703 Commits

Author SHA1 Message Date
Adrian Prantl 816ee8a423 DwarfExpression: Factor out getOrCreateBaseType() (NFC) 2020-01-29 10:23:12 -08:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Adrian Prantl a095d149c2 Fix an assertion failure in DwarfExpression's subregister composition
This patch fixes an assertion failure in DwarfExpression that is
triggered when a complex fragment has exactly the size of a
subregister of the register the DBG_VALUE points to *and* there is no
DWARF encoding for the super-register.

I took the opportunity to replace/document some magic values with
static constructor functions to make this code less confusing to read.

rdar://problem/58489125

Differential Revision: https://reviews.llvm.org/D72938
2020-01-27 12:44:37 -08:00
Vedant Kumar e08f205f5c Reland (again): [DWARF] Allow cross-CU references of subprogram definitions
This is a revert-of-revert (i.e. this reverts commit 802bec89, which
itself reverted fa4701e1 and 79daafc9) with a fix folded in. The problem
was that call site tags weren't emitted properly when LTO was enabled
along with split-dwarf. This required a minor fix. I've added a reduced
test case in test/DebugInfo/X86/fission-call-site.ll.

Original commit message:

This allows a call site tag in CU A to reference a callee DIE in CU B
without resorting to creating an incomplete duplicate DIE for the callee
inside of CU A.

We already allow cross-CU references of subprogram declarations, so it
doesn't seem like definitions ought to be special.

This improves entry value evaluation and tail call frame synthesis in
the LTO setting. During LTO, it's common for cross-module inlining to
produce a call in some CU A where the callee resides in a different CU,
and there is no declaration subprogram for the callee anywhere. In this
case llvm would (unnecessarily, I think) emit an empty DW_TAG_subprogram
in order to fill in the call site tag. That empty 'definition' defeats
entry value evaluation etc., because the debugger can't figure out what
it means.

As a follow-up, maybe we could add a DWARF verifier check that a
DW_TAG_subprogram at least has a DW_AT_name attribute.

Update #1:

Reland with a fix to create a declaration DIE when the declaration is
missing from the CU's retainedTypes list. The declaration is left out
of the retainedTypes list in two cases:

1) Re-compiling pre-r266445 bitcode (in which declarations weren't added
   to the retainedTypes list), and
2) Doing LTO function importing (which doesn't update the retainedTypes
   list).

It's possible to handle (1) and (2) by modifying the retainedTypes list
(in AutoUpgrade, or in the LTO importing logic resp.), but I don't see
an advantage to doing it this way, as it would cause more DWARF to be
emitted compared to creating the declaration DIEs lazily.

Update #2:

Fold in a fix for call site tag emission in the split-dwarf + LTO case.

Tested with a stage2 ThinLTO+RelWithDebInfo build of clang, and with a
ReleaseLTO-g build of the test suite.

rdar://46577651, rdar://57855316, rdar://57840415, rdar://58888440

Differential Revision: https://reviews.llvm.org/D70350
2020-01-27 10:52:34 -08:00
Igor Kudrin 8f3d47c54a [DWARF] Do not pass Version to DWARFExpression. NFCI.
The Version was used only to determine the size of an operand of
DW_OP_call_ref. The size was 4 for all versions apart from 2, but
the DW_OP_call_ref operation was introduced only in DWARF3. Thus,
the code may be simplified and using of Version may be eliminated.

Differential Revision: https://reviews.llvm.org/D73264
2020-01-27 19:08:46 +07:00
David Stenberg 13d4ef9ac0 Improvements to call site register worklist
Summary:
This fixes PR44118. For cases where we have a chain like this:

  R8 = R1 (entry value)
  R0 = R8
  call @foo R0

the code that emits call site entries using entry values would not
follow that chain, instead emitting a call site entry with R8 as
location rather than R0. Such a case was discovered when originally
adding dbgcall-site-orr-moves.mir. This patch fixes that issue. This is
done by changing the ForwardedRegWorklist set to a map in which the
worklist registers always map to the parameter registers that they
describe.

Another thing this patch fixes is that worklist registers now can
describe more than one parameter register at a time. Such a case
occurred in dbgcall-site-interpretation.mir, resulting in a call site
entry not being emitted for one of the parameters.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D73168
2020-01-27 12:41:42 +01:00
David Stenberg b46baa82fc Don't separate imp/expl def handling for call site params
Summary:
Since D70431 the describeLoadedValue() hook takes a parameter register,
meaning that it can now be asked to describe any register. This means
that we can drop the difference between explicit and implicit defines
that we previously had in collectCallSiteParameters().

I have not found any case for any upstream targets where a parameter
register is only implicitly defined, and does not overlap with any
explicit defines. I don't know if such a case would even make sense. So
as far as I have tested, this patch should be a non-functional change.
However, this reduces the complexity of the code a bit, and it will
simplify the implementation of an upcoming patch which solves PR44118.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: djtodoro, vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D73167
2020-01-27 11:31:09 +01:00
Vedant Kumar 802bec8961 Revert "Reland: [DWARF] Allow cross-CU references of subprogram definitions"
... as well as:
Revert "[DWARF] Defer creating declaration DIEs until we prepare call site info"

This reverts commit fa4701e197.

This reverts commit 79daafc903.

There have been reports of this assert getting hit:

CalleeDIE && "Could not find DIE for call site entry origin
2020-01-24 18:07:54 -08:00
Guillaume Chatelet 805c157e8a [Alignment][NFC] Deprecate Align::None()
Summary:
This is a follow up on https://reviews.llvm.org/D71473#inline-647262.
There's a caveat here that `Align(1)` relies on the compiler understanding of `Log2_64` implementation to produce good code. One could use `Align()` as a replacement but I believe it is less clear that the alignment is one in that case.

Reviewers: xbolva00, courbet, bollu

Subscribers: arsenm, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, Jim, kerbowa, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73099
2020-01-24 12:53:58 +01:00
Fangrui Song 22467e2595 Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0
Similar to the function attribute `prefix` (prefix data),
"patchable-function-prefix" inserts data (M NOPs) before the function
entry label.

-fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry)
will look like:

```
  .type	foo,@function
.Ltmp0:               # @foo
  nop
foo:
.Lfunc_begin0:
  # optional `bti c` (AArch64 Branch Target Identification) or
  # `endbr64` (Intel Indirect Branch Tracking)
  nop

  .section  __patchable_function_entries,"awo",@progbits,get,unique,0
  .p2align  3
  .quad .Ltmp0
```

-fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable
placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html):

```
(a)         (b)

func:       func:
.Ltmp0:     bti c
  bti c     .Ltmp0:
  nop       nop
```

(a) needs no additional code. If the consensus is to go for (b), we will
need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp .

Differential Revision: https://reviews.llvm.org/D73070
2020-01-23 17:02:27 -08:00
Djordje Todorovic 91b0956f38 [NFC][DwarfDebug] Use proper analog GNU attribute for the pc address
The low_pc is analog to the DW_AT_call_return_pc, since it describes
the return address after the call. The DW_AT_call_pc is the address
of the call instruction, and we don't use it at the moment.

Differential Revision: https://reviews.llvm.org/D73173
2020-01-23 12:15:35 +01:00
Fangrui Song d232c21566 [AsmPrinter] Don't emit __patchable_function_entries entry if "patchable-function-entry"="0"
Add improve tests
2020-01-20 16:13:48 -08:00
Awanish Pandey 84c4c87e04 Recommit "[DWARF5][DebugInfo]: Added support for DebugInfo generation for auto return type for C++ member functions."
Summary:
This was reverted in 328e0f3dca due to
chromium bot failure. This revision addresses that case.

Original commit message:
Summary:
    This patch will provide support for auto return type for the C++ member
    functions. Before this return type of the member function is deduced and
    stored in the DIE.
    This patch includes llvm side implementation of this feature.

    Patch by: Awanish Pandey <Awanish.Pandey@amd.com>

    Reviewers: dblaikie, aprantl, shafik, alok, SouraVX, jini.susan.george

    Reviewed by: dblaikie

    Differential Revision: https://reviews.llvm.org/D70524
2020-01-20 15:13:13 +05:30
Fangrui Song 9583a3f262 [AsmPrinter] Delete dead takeDeletedSymbsForFunction()
The code added in r98579 is dead now.
2020-01-18 17:08:00 -08:00
David Blaikie 58b10df54f DebugInfo: Move SectionLabel tracking into CU's addRange
This makes the SectionLabel handling more resilient - specifically for
future PROPELLER work which will have more CU ranges (rather than just
one per function).

Ultimately it might be nice to make this more general/resilient to
arbitrary labels (rather than relying on the labels being created for CU
ranges & then being reused by ranges, loclists, and possibly other
addresses). It's possible that other (non-rnglist/loclist) uses of
addresses will need the addresses to be in SectionLabels earlier (eg:
move the CU.addRange to be done on function begin, rather than function
end, so during function emission they are already populated for other
use).
2020-01-17 18:12:34 -08:00
Derek Schuff ff171acf84 [WebAssembly] Track frame registers through VReg and local allocation
This change has 2 components:

Target-independent: add a method getDwarfFrameBase to TargetFrameLowering. It
describes how the Dwarf frame base will be encoded.  That can be a register (the
default), the CFA (which replaces NVPTX-specific logic in DwarfCompileUnit), or
a DW_OP_WASM_location descriptr.

WebAssembly: Allow WebAssemblyFunctionInfo::getFrameRegister to return the
correct virtual register instead of FP32/SP32 after WebAssemblyReplacePhysRegs
has run.  Make WebAssemblyExplicitLocals store the local it allocates for the
frame register. Use this local information to implement getDwarfFrameBase

The result is that the DW_AT_frame_base attribute is correctly encoded for each
subprogram, and each param and local variable has a correct DW_AT_location that
uses DW_OP_fbreg to refer to the frame base.

This is a reland of rG3a05c3969c18 with fixes for the expensive-checks
and Windows builds

Differential Revision: https://reviews.llvm.org/D71681
2020-01-17 17:23:56 -08:00
Adrian Prantl 7b30370e5b Move the sysroot attribute from DIModule to DICompileUnit
[this re-applies c0176916a4
 with the correct commit message and phabricator link]

This addresses point 1 of PR44213.
https://bugs.llvm.org/show_bug.cgi?id=44213

The DW_AT_LLVM_sysroot attribute is used for Clang module debug info,
to allow LLDB to import a Clang module from source. Currently it is
part of each DW_TAG_module, however, it is the same for all modules in
a compile unit. It is more efficient and less ambiguous to store it
once in the DW_TAG_compile_unit.

This should have no effect on DWARF consumers other than LLDB.

Differential Revision: https://reviews.llvm.org/D71732
2020-01-17 12:55:40 -08:00
Adrian Prantl c17aee67f1 Revert "Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot"
This reverts commit 12e479475a.

I accidentally landed this patch with the wrong commit message ...
2020-01-17 12:52:36 -08:00
Adrian Prantl 12e479475a Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot
This is a purely cosmetic change that is NFC in terms of the binary
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot
since the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any
useful information otherwise.

This attribute only appears in Clang module debug info.

Differential Revision: https://reviews.llvm.org/D71722
2020-01-17 09:36:48 -08:00
Derek Schuff 80906d9d16 Revert "[WebAssembly] Track frame registers through VReg and local allocation"
This reverts commit 3a05c3969c.
It breaks under expensive-checks and on Windows
2020-01-16 14:38:00 -08:00
Derek Schuff 3a05c3969c [WebAssembly] Track frame registers through VReg and local allocation
This change has 2 components:

Target-independent: add a method getDwarfFrameBase to TargetFrameLowering. It
describes how the Dwarf frame base will be encoded.  That can be a register (the
default), the CFA (which replaces NVPTX-specific logic in DwarfCompileUnit), or
a DW_OP_WASM_location descriptr.

WebAssembly: Allow WebAssemblyFunctionInfo::getFrameRegister to return the
correct virtual register instead of FP32/SP32 after WebAssemblyReplacePhysRegs
has run.  Make WebAssemblyExplicitLocals store the local it allocates for the
frame register. Use this local information to implement getDwarfFrameBase

The result is that the DW_AT_frame_base attribute is correctly encoded for each
subprogram, and each param and local variable has a correct DW_AT_location that
uses DW_OP_fbreg to refer to the frame base.

Differential Revision: https://reviews.llvm.org/D71681
2020-01-16 13:51:17 -08:00
Vedant Kumar 43464509fc DWARF: Simplify the way the return PC is attached to call site tags, NFC
This cleanup was suggested by Djordje in D72489.
2020-01-15 14:16:21 -08:00
Vedant Kumar f0120556c7 [DWARF] Emit DW_AT_call_return_pc as an address
This reverts D53469, which changed llvm's DWARF emission to emit
DW_AT_call_return_pc as a function-local offset. Such an encoding is not
compatible with post-link block re-ordering tools and isn't standards-
compliant.

In addition to reverting back to the original DW_AT_call_return_pc
encoding, teach lldb how to fix up DW_AT_call_return_pc when the address
comes from an object file pointed-to by a debug map. While doing this I
noticed that lldb's support for tail calls that cross a DSO/object file
boundary wasn't covered, so I added tests for that. This latter case
exercises the newly added return PC fixup.

The dsymutil changes in this patch were originally included in D49887:
the associated test should be sufficient to test DW_AT_call_return_pc
encoding purely on the llvm side.

Differential Revision: https://reviews.llvm.org/D72489
2020-01-15 13:02:23 -08:00
Amy Huang 328e0f3dca Revert "[DWARF5][DebugInfo]: Added support for DebugInfo generation for auto return type for C++ member functions."
This reverts commit c958639098, which
causes a crash. See https://reviews.llvm.org/D70524 for details.
2020-01-13 13:58:14 -08:00
Awanish Pandey c958639098 [DWARF5][DebugInfo]: Added support for DebugInfo generation for auto return type for C++ member functions.
Summary:
This patch will provide support for auto return type for the C++ member
functions. Before this return type of the member function is deduced and
stored in the DIE.
This patch includes llvm side implementation of this feature.

Patch by: Awanish Pandey <Awanish.Pandey@amd.com>

Reviewers: dblaikie, aprantl, shafik, alok, SouraVX, jini.susan.george

Reviewed by: dblaikie

Differential Revision: https://reviews.llvm.org/D70524
2020-01-13 12:26:13 +05:30
Fangrui Song 7fa5290d5b __patchable_function_entries: don't use linkage field 'unique' with -no-integrated-as
.section name, "flags"G, @type, GroupName[, linkage]

As of binutils 2.33, linkage cannot be 'unique'.  For integrated
assembler, we use both 'o' flag and 'unique' linkage to support
--gc-sections and COMDAT with lld.

https://sourceware.org/ml/binutils/2019-11/msg00266.html
2020-01-12 12:53:44 -08:00
Fangrui Song 4d1e23e3b3 [AArch64] Add function attribute "patchable-function-entry" to add NOPs at function entry
The Linux kernel uses -fpatchable-function-entry to implement DYNAMIC_FTRACE_WITH_REGS
for arm64 and parisc. GCC 8 implemented
-fpatchable-function-entry, which can be seen as a generalized form of
-mnop-mcount. The N,M form (function entry points before the Mth NOP) is
currently only used by parisc.

This patch adds N,0 support to AArch64 codegen. N is represented as the
function attribute "patchable-function-entry". We will use a different
function attribute for M, if we decide to implement it.

The patch reuses the existing patchable-function pass, and
TargetOpcode::PATCHABLE_FUNCTION_ENTER which is currently used by XRay.

When the integrated assembler is used, __patchable_function_entries will
be created for each text section with the SHF_LINK_ORDER flag to prevent
--gc-sections (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93197) and
COMDAT (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93195) issues.

Retrospectively, __patchable_function_entries should use a PC-relative
relocation type to avoid the SHF_WRITE flag and dynamic relocations.

"patchable-function-entry"'s interaction with Branch Target
Identification is still unclear (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 for GCC discussions).

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D72215
2020-01-10 09:55:51 -08:00
Bill Wendling 83d690a149 Don't rely on 'l'(ell) modifiers to indicate a label reference
Summary:
It's not necessary to use an 'l'(ell) modifier when referencing a label.
Treat block addresses and MBB references as if the modifier is used
anyway. This prevents us from generating references to ficticious
labels.

Reviewers: jyknight, nickdesaulniers, hfinkel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71849
2020-01-06 14:44:03 -08:00
David Blaikie fccac1ec16 DebugInfo: Correct the form of DW_AT_macro_info in .dwo files (sec_offset, rather than data4) 2019-12-24 01:23:21 -08:00
David Blaikie 83c7a424d9 DebugInfo: Add {} to address -Wdangling-else warning. 2019-12-24 01:14:15 -08:00
Sourabh Singh Tomar 0a72515d33 [DebugInfo] Fix v4 macinfo for dwo files.
Dwo files must contain have DW_AT_macro_info attribute, when macro information is emitted. Adjusted the test case
for the same.
2019-12-24 12:50:34 +05:30
Eric Astor dc5b614fa9 [ms] [X86] Use "P" modifier on operands to call instructions in inline X86 assembly.
Summary:
This is documented as the appropriate template modifier for call operands.
Fixes PR44272, and adds a regression test.

Also adds support for operand modifiers in Intel-style inline assembly.

Reviewers: rnk

Reviewed By: rnk

Subscribers: merge_guards_bot, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71677
2019-12-22 09:16:34 -05:00
David Blaikie d0bfb3c583 DebugInfo: Remove out of date comment 2019-12-21 23:13:26 -08:00
Vedant Kumar fa4701e197 [DWARF] Defer creating declaration DIEs until we prepare call site info
It isn't necessary to create DIEs for all of the declaration subprograms
in a CU's retainedTypes list. We can defer creating these subprograms
until we need to prepare a call site tag that refers to one.

This cleanup was mentioned in passing in D70350.
2019-12-20 15:26:31 -08:00
Vedant Kumar 79daafc903 Reland: [DWARF] Allow cross-CU references of subprogram definitions
This allows a call site tag in CU A to reference a callee DIE in CU B
without resorting to creating an incomplete duplicate DIE for the callee
inside of CU A.

We already allow cross-CU references of subprogram declarations, so it
doesn't seem like definitions ought to be special.

This improves entry value evaluation and tail call frame synthesis in
the LTO setting. During LTO, it's common for cross-module inlining to
produce a call in some CU A where the callee resides in a different CU,
and there is no declaration subprogram for the callee anywhere. In this
case llvm would (unnecessarily, I think) emit an empty DW_TAG_subprogram
in order to fill in the call site tag. That empty 'definition' defeats
entry value evaluation etc., because the debugger can't figure out what
it means.

As a follow-up, maybe we could add a DWARF verifier check that a
DW_TAG_subprogram at least has a DW_AT_name attribute.

Update:

Reland with a fix to create a declaration DIE when the declaration is
missing from the CU's retainedTypes list. The declaration is left out
of the retainedTypes list in two cases:

1) Re-compiling pre-r266445 bitcode (in which declarations weren't added
   to the retainedTypes list), and
2) Doing LTO function importing (which doesn't update the retainedTypes
   list).

It's possible to handle (1) and (2) by modifying the retainedTypes list
(in AutoUpgrade, or in the LTO importing logic resp.), but I don't see
an advantage to doing it this way, as it would cause more DWARF to be
emitted compared to creating the declaration DIEs lazily.

Tested with a stage2 ThinLTO+RelWithDebInfo build of clang, and with a
ReleaseLTO-g build of the test suite.

rdar://46577651, rdar://57855316, rdar://57840415

Differential Revision: https://reviews.llvm.org/D70350
2019-12-20 15:26:31 -08:00
Yury Delendik adf7a0a558 [WebAssembly] Use TargetIndex operands in DbgValue to track WebAssembly operands locations
Extends DWARF expression language to express locals/globals locations. (via
target-index operands atm) (possible variants are: non-virtual registers
or address spaces)

The WebAssemblyExplicitLocals can replace virtual registers to targertindex
operand type at the time when WebAssembly backend introduces
{get,set,tee}_local instead of corresponding virtual registers.

Reviewed By: aprantl, dschuff

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D52634
2019-12-20 14:39:05 -08:00
Adrian Prantl 44b4b833ad Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot
This is a purely cosmetic change that is NFC in terms of the binary
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot
since the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any
useful information otherwise.

This attribute only appears in Clang module debug info.

Differential Revision: https://reviews.llvm.org/D71722
2019-12-20 13:11:17 -08:00
Tom Weaver 453dc4d7ec [OPT-DBG] Teach DbgEntityHistoryCalculator about meta-instructions.
The calculator was considering instructions such as KILLs as clobbers
of a physical address. This is wrong as meta instructions such as KILLs
produce no output in the final program and thus don't clobber or change
any physical location's value. As a result they're safe to ignore whilst
calculating location list ranges.

reviewers: aprantl, vsk

diff revision: https://reviews.llvm.org/D70497

fixes: https://bugs.llvm.org/show_bug.cgi?id=38753
2019-12-20 14:03:34 +00:00
David Blaikie aaa5a5e7ff DebugInfo: Include DW_AT_base_addr even in gmlt with no inline functions
Since the address pool doesn't get populated in this case (due to the
lack of inlining, no child DIEs are added to the CU - so no addresses
are needed for the DIEs themselves) until the range list is emitted - at
the time the attributes are added to the CU, the address pool is empty.
So check whether the address pool will be used for the range lists & add
an addr_base if that's the case.
2019-12-18 17:14:28 -08:00
David Blaikie 64fa76ef55 Reapply "NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List"
Move these data structures closer together so their emission code can
eventually share more of its implementation.

Was an egregious bug (completely untested, evidently) where I hadn't
inverted a DWARFv5 test as needed, so it was doing the exact opposite of
what was required & thus tried to emit a DWARFv5 range list header in
DWARFv4.

Reapply 8e04896288 which was
reverted in a8154e5e0c.
2019-12-18 16:28:19 -08:00
Sourabh Singh Tomar 399273e5eb Recommit "[DebugInfo] Refactored macro related generation,
added a test case for macinfo.dwo emission."

This was reverted in caa4120906,
since it was causing an assertion failure on Windows bots.
This revision is revised to fix that.

Original commit message -

[DebugInfo] Refactored macro related generation, added a test case for macinfo.dwo emission.

Reviewers: dblaikie, aprantl, jini.susan.george

Tags: #debug-info #llvm

Differential Revision: https://reviews.llvm.org/D71008
2019-12-18 02:12:59 +05:30
Raphael Isemann ccfab8e459 [ObjC][DWARF] Emit DW_AT_APPLE_objc_direct for methods marked as __attribute__((objc_direct))
Summary:
With DWARF5 it is no longer possible to distinguish normal methods and methods with `__attribute__((objc_direct))` by just looking at the debug information
as they are both now children of the of the DW_TAG_structure_type that defines them (before only the `__attribute__((objc_direct))` methods were children).

This means that in LLDB we are no longer able to create a correct Clang AST of a module by just looking at the debug information. Instead we would
need to call the Objective-C runtime to see which of the methods have a `__attribute__((objc_direct))` and then add the attribute to our own Clang AST
depending on what the runtime returns. This would mean that we either let the module AST be dependent on the Objective-C runtime (which doesn't
seem right) or we retroactively add the missing attribute to the imported AST in our expressions.

A third option is to annotate methods with `__attribute__((objc_direct))` as `DW_AT_APPLE_objc_direct` which is what this patch implements. This way
LLDB doesn't have to call the runtime for any `__attribute__((objc_direct))` method and the AST in our module will already be correct when we create it.

Reviewers: aprantl, SouraVX

Reviewed By: aprantl

Subscribers: hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D71201
2019-12-17 09:40:36 +01:00
Eric Christopher a8154e5e0c Temporarily revert "NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List"
as it was causing bot and build failures.

This reverts commit 8e04896288.
2019-12-12 17:55:41 -08:00
David Blaikie 8e04896288 NFC: DebugInfo: Refactor RangeSpanList to be a struct, like DebugLocStream::List
Move these data structures closer together so their emission code can
eventually share more of its implementation.
2019-12-12 16:53:59 -08:00
David Blaikie 20e06a28da NFC: DebugInfo: Refactor debug_loc/loclist emission into a common function
(except for v4 loclists, which are sufficiently different to not fit
well in this generic implementation)

In subsequent patches I intend to refactor the DebugLoc and ranges data
structures to be more similar so I can common more of the implementation
here.
2019-12-12 16:39:12 -08:00
Evgenii Stepanov dabd2622a8 hwasan: add tag_offset DWARF attribute to optimized debug info
Summary:
Support alloca-referencing dbg.value in hwasan instrumentation.
Update AsmPrinter to emit DW_AT_LLVM_tag_offset when location is in
loclist format.

Reviewers: pcc

Subscribers: srhines, aprantl, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70753
2019-12-12 16:18:54 -08:00
Vedant Kumar 56232f950d Revert "[DWARF] Allow cross-CU references of subprogram definitions"
This reverts commit 30038da15b. It causes
the stage2 thinLTO bot to fail with:

Assertion failed: (CU.getDIE(CalleeSP) && "Expected declaration subprogram DIE for callee")

rdar://57840415
2019-12-11 15:55:48 -08:00
Nico Weber caa4120906 Revert "[DebugInfo] Refactored macro related generation, added a test case for macinfo.dwo emission."
This reverts commit 307f60a1a3.

DebugInfo/X86/debug-macinfo-split-dwarf.ll fails on Windows:

Command Output (stdout):
--
$ ":" "RUN: at line 1"
$ "c:\src\llvm-project\out\gn\bin\llc.exe" "-mtriple=x86_64-pc-windows-gnu" "-O0" "-split-dwarf-file=foo.dwo" "-filetype=obj"
Assertion failed: Section && "Cannot switch to a null section!", file ../../llvm/lib/MC/MCStreamer.cpp, line 1103
Stack dump:
0.	Program arguments: c:\src\llvm-project\out\gn\bin\llc.exe -mtriple=x86_64-pc-windows-gnu -O0 -split-dwarf-file=foo.dwo -filetype=obj
2019-12-10 21:32:30 -05:00
David Blaikie 4ffd3f44e3 DebugInfo: Clarify some more reasons v4 loc.dwo can't share much implementation with loclists.dwo 2019-12-10 14:11:03 -08:00
Vedant Kumar 30038da15b [DWARF] Allow cross-CU references of subprogram definitions
This allows a call site tag in CU A to reference a callee DIE in CU B
without resorting to creating an incomplete duplicate DIE for the callee
inside of CU A.

We already allow cross-CU references of subprogram declarations, so it
doesn't seem like definitions ought to be special.

This improves entry value evaluation and tail call frame synthesis in
the LTO setting. During LTO, it's common for cross-module inlining to
produce a call in some CU A where the callee resides in a different CU,
and there is no declaration subprogram for the callee anywhere. In this
case llvm would (unnecessarily, I think) emit an empty DW_TAG_subprogram
in order to fill in the call site tag. That empty 'definition' defeats
entry value evaluation etc., because the debugger can't figure out what
it means.

As a follow-up, maybe we could add a DWARF verifier check that a
DW_TAG_subprogram at least has a DW_AT_name attribute.

rdar://46577651

Differential Revision: https://reviews.llvm.org/D70350
2019-12-10 14:00:57 -08:00
Sourabh Singh Tomar 307f60a1a3 [DebugInfo] Refactored macro related generation, added a test case for macinfo.dwo emission.
Reviewers: dblaikie, aprantl, jini.susan.george

Tags: #debug-info #llvm

Differential Revision: https://reviews.llvm.org/D71008
2019-12-11 02:19:27 +05:30
Sourabh Singh Tomar fb4d8fe1a8 Recommit "[DWARF5] Start emitting DW_AT_dwo_name when -gdwarf-5 is specified."
Reviewers: dblaikie, aprantl, probinson

Tags: #debug-info #llvm

Differential Revision: https://reviews.llvm.org/D71185
2019-12-11 01:24:50 +05:30
Sourabh Singh Tomar d82b6ba21b Revert "[DWARF5] Start emitting DW_AT_dwo_name when -gdwarf-5 is specified."
This reverts commit 6ef01588f4.
Missing Differetial revision.
2019-12-11 01:20:40 +05:30
Sourabh Singh Tomar 6ef01588f4 [DWARF5] Start emitting DW_AT_dwo_name when -gdwarf-5 is specified. 2019-12-11 01:18:02 +05:30
Fangrui Song 9574757dba [MC] Delete MCCodePadder
D34393 added MCCodePadder as an infrastructure for padding code with
NOP instructions. It lacked tests and was not being worked on since
then.

Intel has now worked on an assembler patch to mitigate performance loss
after applying microcode update for the Jump Conditional Code Erratum.

https://www.intel.com/content/www/us/en/support/articles/000055650/processors.html

This new patch shares similarity with MCCodePadder, but has a concrete
use case in mind and is being actively developed. The infrastructure it
introduces can potentially be used for general performance improvement
via alignment. Delete the unused MCCodePadder so that people can develop
the new feature from a clean state.

Reviewed By: jyknight, skan

Differential Revision: https://reviews.llvm.org/D71106
2019-12-09 19:21:31 -08:00
Hiroshi Yamauchi d9ae493937 [PGO][PGSO] Instrument the code gen / target passes.
Summary:
Split off of D67120.

Add the profile guided size optimization instrumentation / queries in the code
gen or target passes. This doesn't enable the size optimizations in those passes
yet as they are currently disabled in shouldOptimizeForSize (for non-IR pass
queries).

A second try after reverted D71072.

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71149
2019-12-09 12:42:59 -08:00
David Stenberg 6965f835b4 [DebugInfo] Make describeLoadedValue() reg aware
Summary:
Currently the describeLoadedValue() hook is assumed to describe the
value of the instruction's first explicit define. The hook will not be
called for instructions with more than one explicit define.

This commit adds a register parameter to the describeLoadedValue() hook,
and invokes the hook for all registers in the worklist.

This will allow us to for example describe instructions which produce
more than two parameters' values; e.g. Hexagon's various combine
instructions.

This also fixes situations in our downstream target where we may pass
smaller parameters in the high part of a register. If such a parameter's
value is produced by a larger copy instruction, we can't describe the
call site value using the super-register, and we instead need to know
which sub-register that should be used.

This also allows us to handle cases like this:

  $ebx = [...]
  $rdi = MOVSX64rr32 $ebx
  $esi = MOV32rr $edi
  CALL64pcrel32 @call

The hook will first be invoked for the MOV32rr instruction, which will
say that @call's second parameter (passed in $esi) is described by $edi.
As $edi is not preserved it will be added to the worklist. When we get
to the MOVSX64rr32 instruction, we need to describe two values; the
sign-extended value of $ebx -> $rdi for the first parameter, and $ebx ->
$edi for the second parameter, which is now possible.

This commit modifies the dbgcall-site-lea-interpretation.mir test case.
In the test case, the values of some 32-bit parameters were produced
with LEA64r. Perhaps we can in general cases handle such by emitting
expressions that AND out the lower 32-bits, but I have not been able to
land in a case where a LEA64r is used for a 32-bit parameter instead of
LEA64_32 from C code.

I have not found a case where it would be useful to describe parameters
using implicit defines, so in this patch the hook is still only invoked
for explicit defines of forwarding registers.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: djtodoro, vsk

Subscribers: ormris, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D70431
2019-12-09 10:47:49 +01:00
David Stenberg f3696533f2 Revert "[DebugInfo] Make describeLoadedValue() reg aware"
This reverts commit 3cd93a4efc.
I'll recommit with a well-formatted arcanist commit message.
2019-12-09 10:45:13 +01:00
David Stenberg 3cd93a4efc [DebugInfo] Make describeLoadedValue() reg aware
Currently the describeLoadedValue() hook is assumed to describe the
value of the instruction's first explicit define. The hook will not be
called for instructions with more than one explicit define.

This commit adds a register parameter to the describeLoadedValue() hook,
and invokes the hook for all registers in the worklist.

This will allow us to for example describe instructions which produce
more than two parameters' values; e.g. Hexagon's various combine
instructions.

This also fixes a case in our downstream target where we may pass
smaller parameters in the high part of a register. If such a parameter's
value is produced by a larger copy instruction, we can't describe the
call site value using the super-register, and we instead need to know
which sub-register that should be used.

This also allows us to handle cases like this:

  $ebx = [...]
  $rdi = MOVSX64rr32 $ebx
  $esi = MOV32rr $edi
  CALL64pcrel32 @call

The hook will first be invoked for the MOV32rr instruction, which will
say that @call's second parameter (passed in $esi) is described by $edi.
As $edi is not preserved it will be added to the worklist. When we get
to the MOVSX64rr32 instruction, we need to describe two values; the
sign-extended value of $ebx -> $rdi for the first parameter, and $ebx ->
$edi for the second parameter, which is now possible.

This commit modifies the dbgcall-site-lea-interpretation.mir test case.
In the test case, the values of some 32-bit parameters were produced
with LEA64r. Perhaps we can in general cases handle such by emitting
expressions that AND out the lower 32-bits, but I have not been able to
land in a case where a LEA64r is used for a 32-bit parameter instead of
LEA64_32 from C code.

I have not found a case where it would be useful to describe parameters
using implicit defines, so in this patch the hook is still only invoked
for explicit defines of forwarding registers.
2019-12-09 10:44:17 +01:00
Hiroshi Yamauchi 2eb30fafa5 Revert "[PGO][PGSO] Instrument the code gen / target passes."
This reverts commit 9a0b5e1407.

This seems to break buildbots.
2019-12-06 12:17:32 -08:00
Hiroshi Yamauchi 9a0b5e1407 [PGO][PGSO] Instrument the code gen / target passes.
Summary:
Split off of D67120.

Add the profile guided size optimization instrumentation / queries in the code
gen or target passes. This doesn't enable the size optimizations in those passes
yet as they are currently disabled in shouldOptimizeForSize (for non-IR pass
queries).

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71072
2019-12-06 10:43:39 -08:00
David Blaikie 560ab1f8d3 DebugInfo: Pull out a common expression.
This is for the case where -gmlt -gsplit-dwarf -fsplit-dwarf-inlining
are used together in some but not all units during LTO (or, in the
reduced case, even without LTO) - ensuring that no split dwarf is used
(because split-dwarf-inlining puts the same data in the .o file, so
there's no need to duplicate it into the .dwo file)
2019-12-05 19:51:30 -08:00
David Blaikie decee04e63 DebugInfo: Fix LTO+DWARFv5 loclists
The loclists_table_base was being overwritten for each CU even though
only one loclists contribution is made so everything but the last CU
would have a label that was never defined and fail to assemble.
2019-12-05 12:47:54 -08:00
David Stenberg 54682d871d [DebugInfo] Handle call site values for instructions before call bundle
Summary:
If a call is bundled then the code that looks for instructions that
produce parameter values would break when reaching the call's bundle
header, due to the `ifCall(/*AnyInBundle*/)` invocation returning true.

It is not enough to simply ignore bundle headers in the `isCall()`
invocation, as the bundle header may have defines of parameter registers
due to the call, meaning that such registers would incorrectly be
removed from the worklist. Therefore, do not look at bundle headers at
all.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: aprantl, vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D71024
2019-12-05 11:50:41 +01:00
Alexey Lapshin 789e257ce0 [DWARF5][Debuginfo] Compilation unit type (DW_UT_skeleton) and root DIE (DW_TAG_compile_unit) do not match.
That patch fixes incompatible compilation unit type (DW_UT_skeleton) and root DIE (DW_TAG_compile_unit) error.

cat split-dwarf.cpp
int main()
{
  int a = 1;
  return 0;
}

clang++ -O -g -gsplit-dwarf -gdwarf-5 split-dwarf.cpp; llvm-dwarfdump --verify ./a.out | grep skeleton
error: Compilation unit type (DW_UT_skeleton) and root DIE (DW_TAG_compile_unit) do not match.

The fix is to change DW_TAG_compile_unit into DW_TAG_skeleton_unit when skeleton file is generated.

Differential Revision: https://reviews.llvm.org/D70880
2019-12-05 00:53:47 +03:00
Sourabh Singh Tomar 8dd17a13b0 [NFCI][DebugInfo] Corrected a comment. 2019-12-03 19:45:37 +05:30
Sourabh Singh Tomar f1e3988aa6 Recommit "[DWARF5]Addition of alignment atrribute in typedef DIE."
This revision is revised to update Go-bindings and Release Notes.

The original commit message follows.

This patch, adds support for DW_AT_alignment[DWARF5] attribute, to be emitted with typdef DIE.
When explicit alignment is specified.

Patch by Awanish Pandey <Awanish.Pandey@amd.com>

Reviewers: aprantl, dblaikie, jini.susan.george, SouraVX, alok,
deadalinx

Differential Revision: https://reviews.llvm.org/D70111
2019-12-03 09:51:43 +05:30
Sourabh Singh Tomar 3f3d0f4f4b [DebugInfo] Support for debug_macinfo.dwo section in llvm and llvm-dwarfdump.
This patch adds support for debug_macinfo.dwo section[pre-standardized]
to llvm and llvm-dwarfdump.

Reviewers: probinson, dblaikie, aprantl, jini.susan.george, alok

Differential Revision: https://reviews.llvm.org/D70705

Tags: #debug-info #llvm
2019-12-03 08:54:12 +05:30
Sourabh Singh Tomar 0e02977b6e Recommit "[DWARF] Support for loclist.dwo section in llvm and llvm-dwarfdump."
The original commit message follows.

This patch adds support for debug_loclists.dwo section in llvm and llvm-dwarfdump.
Also Fixes PR43622, PR43623.

Reviewers: dblaikie, probinson, labath, aprantl, jini.susan.george

Differential Revision: https://reviews.llvm.org/D69462
2019-11-23 20:10:23 +05:30
Sourabh Singh Tomar 02cb4b2fd6 Revert "[DWARF] Support for loclist.dwo section in llvm and llvm-dwarfdump."
This reverts commit 81b0a3284a.
Will Re-apply, with updated Differtial Revision, for automatic closure of
Phabricator review.
2019-11-23 19:46:07 +05:30
Sourabh Singh Tomar 81b0a3284a [DWARF] Support for loclist.dwo section in llvm and llvm-dwarfdump.
This patch adds support for debug_loclists.dwo section in llvm and llvm-dwarfdump.
Also Fixes PR43622, PR43623.

Reviewers: dblaikie, probinson, labath, aprantl, jini.susan.george

https://reviews.llvm.org/D69462
2019-11-23 10:25:11 +05:30
Tom Stellard ab411801b8 [cmake] Explicitly mark libraries defined in lib/ as "Component Libraries"
Summary:
Most libraries are defined in the lib/ directory but there are also a
few libraries defined in tools/ e.g. libLLVM, libLTO.  I'm defining
"Component Libraries" as libraries defined in lib/ that may be included in
libLLVM.so.  Explicitly marking the libraries in lib/ as component
libraries allows us to remove some fragile checks that attempt to
differentiate between lib/ libraries and tools/ libraires:

1. In tools/llvm-shlib, because
llvm_map_components_to_libnames(LIB_NAMES "all") returned a list of
all libraries defined in the whole project, there was custom code
needed to filter out libraries defined in tools/, none of which should
be included in libLLVM.so.  This code assumed that any library
defined as static was from lib/ and everything else should be
excluded.

With this change, llvm_map_components_to_libnames(LIB_NAMES, "all")
only returns libraries that have been added to the LLVM_COMPONENT_LIBS
global cmake property, so this custom filtering logic can be removed.
Doing this also fixes the build with BUILD_SHARED_LIBS=ON
and LLVM_BUILD_LLVM_DYLIB=ON.

2. There was some code in llvm_add_library that assumed that
libraries defined in lib/ would not have LLVM_LINK_COMPONENTS or
ARG_LINK_COMPONENTS set.  This is only true because libraries
defined lib lib/ use LLVMBuild.txt and don't set these values.
This code has been fixed now to check if the library has been
explicitly marked as a component library, which should now make it
easier to remove LLVMBuild at some point in the future.

I have tested this patch on Windows, MacOS and Linux with release builds
and the following combinations of CMake options:

- "" (No options)
- -DLLVM_BUILD_LLVM_DYLIB=ON
- -DLLVM_LINK_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_BUILD_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_LINK_LLVM_DYLIB=ON

Reviewers: beanz, smeenai, compnerd, phosek

Reviewed By: beanz

Subscribers: wuzish, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, mgorny, mehdi_amini, sbc100, jgravelle-google, hiraditya, aheejin, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, dang, Jim, lenary, s.egerton, pzheng, sameer.abuasal, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70179
2019-11-21 10:48:08 -08:00
Adrian Prantl 5da385fb56 Fix an offset underflow bug in DwarfExpression when describing small values with subregisters
DwarfExpression::addMachineReg() knows how to build a larger register
that isn't expressible in DWARF by combining multiple
subregisters. However, if the entire value fits into just one
subregister, it would still emit the other subregisters, leading to
all sorts of inconsistencies down the line.

This patch fixes that by moving an already existing(!) check whether
the subregister's offset is before the end of the value to the right
place.

rdar://problem/57294211

Differential Revision: https://reviews.llvm.org/D70508
2019-11-20 17:07:54 -08:00
Xiangling Liao ca33727abe [AIX] Lowering jump table, constant pool and block address in asm
This patch lowering jump table, constant pool and block address in assembly.
1. On AIX, jump table index is always relative;
2. Put CPI and JTI into ReadOnlySection until we support unique data sections;
3. Create the temp symbol for block address symbol;
4. Update MIR testcases and add related assembly part;

Differential Revision: https://reviews.llvm.org/D70243
2019-11-20 10:27:15 -05:00
Thomas Preud'homme a89ca4ae17 Fix PR44001: assert failure in getFunctionLocalOffsetAfterInsn
Summary:
Assert in getFunctionLocalOffsetAfterInsn() fails when processing a call
MachineInstr inside a bundle and compiling with debug info. This is
because labels are added by DwarfDebug::beginInstruction() which is
called for each top-level MI by EmitFunctionBody()'s for-loop iteration
but constructCallSiteEntryDIEs() which calls
getFunctionLocalOffsetAfterInsn() iterates over all MIs.

This commit modifies constructCallSiteEntryDIEs() to get the associated
bundle MI for call MIs inside a bundle and use that to when calling
getFunctionLocalOffsetAfterInsn() and getLabelAfterInsn(). It also skips
loop iterations for bundle MIs since the loop statements are concerned
with debug info for each physical instructions and bundles represent a
group of instructions. It also fix the comment about PCAddr since the
code is getting the return address and not the call address.

Reviewers: dstenb, vsk, aprantl, djtodoro, dblaikie, NikolaPrica

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70293
2019-11-19 11:23:11 +00:00
Sam McCall d27a16eb39 Revert "[DWARF5]Addition of alignment atrribute in typedef DIE."
This reverts commit 423f541c1a, which
breaks llvm-c ABI.
2019-11-18 15:53:22 +01:00
Sourabh Singh Tomar 423f541c1a [DWARF5]Addition of alignment atrribute in typedef DIE.
This patch, adds support for DW_AT_alignment[DWARF5] attribute, to be emitted with typdef DIE.
When explicit alignment is specified.

Patch by Awanish Pandey <Awanish.Pandey@amd.com>

Reviewers: aprantl, dblaikie, jini.susan.george, SouraVX, alok,
deadalinx

Differential Revision: https://reviews.llvm.org/D70111
2019-11-16 21:56:53 +05:30
David Blaikie 77cfcd7509 DebugInfo: Use loclistx for DWARFv5 location lists to reduce the number of relocations
This only implements the non-dwo part, but loclistx is necessary to use
location lists in DWARFv5, so it's a precursor to that work - and
generally reduces relocations (only using one reloc, then
indexes/relative offsets for all location list references) in non-split
DWARF.
2019-11-15 18:51:13 -08:00
Vedant Kumar 1ee84e5ab2 [DebugInfo] Allow spill slots in call site parameter descriptions
Allow call site paramter descriptions to reference spill slots. Spill
slots are not visible to high-level LLVM IR, so they can safely be
referenced during entry value evaluation (as they cannot be clobbered by
some other function).

This gives a 5% increase in the number of call site parameter DIEs in an
LTO x86_64 build of the xnu kernel.

This reverts commit eb4c98ca3d (
[DebugInfo] Exclude memory location values as parameter entry values),
effectively reintroducing the portion of D60716 which dealt with memory
locations (authored by Djordje, Nikola, Ananth, and Ivan).

This partially addresses llvm.org/PR43343. However, not all memory
operands forwarded to callees live in spill slots. In the xnu build, it
may be possible to use an escape analysis to increase the number of call
site parameter by another 15% (more details in PR43343).

Differential Revision: https://reviews.llvm.org/D70254
2019-11-14 12:48:51 -08:00
David Stenberg 7417cc149b Fix typo in DwarfDebug [NFC] 2019-11-13 18:06:16 +01:00
David Blaikie db797bfb2b DebugInfo: Remove redundant conditionals/checks from macro info emission
These checks fall out naturally from the current implementation without
needing to be explicitly considered anymore.
2019-11-08 15:31:15 -08:00
David Blaikie 736273c7fe DebugInfo: Do not create a debug_macinfo section if no CUs have associated macros
Patch based on Sourabh Singh's D69839 patch.
2019-11-08 15:30:11 -08:00
David Blaikie 3951245c38 NVPTX: Don't insert an extra empty line at the end of the last section.
This was arbitrarily appearing in only the last section emitted - which
made tests more sensitive than they needed to be (removing the last
section - like the macinfo section change that's coming after this)
would, surprisingly, move the blank line to the previous section.
2019-11-08 15:16:04 -08:00
David Blaikie 39c308f6b8 DebugInfo: Use separate macinfo contributions for each CU
The macinfo support was broken for LTO situations, by terminating
macinfo lists only once - multiple macinfo contributions were correctly
labeled, but they all continued/flowed into later contributions until
only one terminator appeared at the end of the section.

Correctly terminate each contribution & fix the parsing to handle this
situation too. The parsing fix is also necessary for dumping linked
binaries - the previous code would stop at the end of the first
contribution - missing all later contributions in a linked binary.

It'd be nice to improve the dumping to print the offsets of each
contribution so it'd be easier to know which CU AT_macro_info refers to
which macinfo contribution.
2019-11-08 13:27:00 -08:00
Hans Wennborg ff3b513495 Revert d91ed80 "[codeview] Reference types in type parent scopes"
This triggered asserts in the Chromium build, see https://crbug.com/1022729 for
details and reproducer.

> Without this change, when a nested tag type of any kind (enum, class,
> struct, union) is used as a variable type, it is emitted without
> emitting the parent type. In CodeView, parent types point to their inner
> types, and inner types do not point back to their parents. We already
> walk over all of the parent scopes to build the fully qualified name.
> This change simply requests their type indices as we go along to enusre
> they are all emitted.
>
> Fixes PR43905
>
> Reviewers: akhuang, amccarth
>
> Differential Revision: https://reviews.llvm.org/D69924
2019-11-08 11:30:33 +01:00
Reid Kleckner d91ed80e97 [codeview] Reference types in type parent scopes
Without this change, when a nested tag type of any kind (enum, class,
struct, union) is used as a variable type, it is emitted without
emitting the parent type. In CodeView, parent types point to their inner
types, and inner types do not point back to their parents. We already
walk over all of the parent scopes to build the fully qualified name.
This change simply requests their type indices as we go along to enusre
they are all emitted.

Fixes PR43905

Reviewers: akhuang, amccarth

Differential Revision: https://reviews.llvm.org/D69924
2019-11-07 13:58:01 -08:00
David Blaikie 89b7f16204 DebugInfo: Streamline debug_ranges/rnglists/rnglists.dwo emission code
More code reuse, better basis for modelling
debug_loc/loclists/loclists.dwo emission support.
2019-11-01 14:56:43 -07:00
Reid Kleckner f5d935c167 [WinCFG] Handle constant casts carefully in .gfids emission
Summary:
The general Function::hasAddressTaken has two issues that make it
inappropriate for our purposes:
1. it is sensitive to dead constant users (PR43858 / crbug.com/1019970),
   leading to different codegen when debu info is enabled
2. it considers direct calls via a function cast to be address escapes

The first is fixable, but the second is not, because IPO clients rely on
this behavior. They assume this function means that all call sites are
analyzable for IPO purposes.

So, implement our own analysis, which gets closer to finding functions
that may be indirect call targets.

Reviewers: ajpaverd, efriedma, hans

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69676
2019-11-01 13:32:03 -07:00
David Candler 92aa0c2dbc [cfi] Add flag to always generate .debug_frame
This adds a flag to LLVM and clang to always generate a .debug_frame
section, even if other debug information is not being generated. In
situations where .eh_frame would normally be emitted, both .debug_frame
and .eh_frame will be used.

Differential Revision: https://reviews.llvm.org/D67216
2019-10-31 09:48:30 +00:00
Djordje Todorovic 532815dd5c [ARM][AArch64][DebugInfo] Improve call site instruction interpretation
Extend the describeLoadedValue() with support for target specific ARM and
AArch64 instructions interpretation. The patch provides specialization for
ADD and SUB operations that include a register and an immediate/offset
operand. Some of the instructions can operate with global string addresses
or constant pool indexes but such cases are omitted since we currently lack
flexible support for processing such operands at DWARF production stage.

Patch by Nikola Prica

Differential Revision: https://reviews.llvm.org/D67556
2019-10-30 13:58:14 +01:00
Adrian Prantl f919be3365 [DWARF5] Added support for deleted C++ special member functions.
This patch adds support for deleted C++ special member functions in
clang and llvm. Also added Defaulted member encodings for future
support for defaulted member functions.

Patch by Sourabh Singh Tomar!

Differential Revision: https://reviews.llvm.org/D69215
2019-10-29 13:44:06 -07:00
Amy Huang 742043047c Recommit "Add a heap alloc site marker field to the ExtraInfo in MachineInstrs"
Summary:
Fixes some things from original commit at https://reviews.llvm.org/D69136. The main
change is that the heap alloc marker is always stored as ExtraInfo in the machine
instruction instead of in the PointerSumType because it cannot hold more than
4 pointer types.

Add instruction marker to MachineInstr ExtraInfo. This does almost the
same thing as Pre/PostInstrSymbols, except that it doesn't create a label until
printing instructions. This allows for labels to be put around instructions that
are deleted/duplicated somewhere.
Use this marker to track heap alloc site call instructions.

Reviewers: rnk

Subscribers: MatzeB, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69536
2019-10-28 16:59:32 -07:00
Francis Visoiu Mistrih c7557dd692 [Remarks] Remove references to ELF support
There is no ELF support at the moment.

Remove all the references to the `.remarks` section.
2019-10-28 12:50:46 -07:00
Francis Visoiu Mistrih 209d5a12c5 [Remarks] Emit the remarks section by default for certain formats
Emit a remarks section by default for the following formats:

* bitstream
* yaml-strtab

while still providing -remarks-section=<bool> to override the defaults.
2019-10-28 12:50:46 -07:00
Andrew Paverd d157a9bc8b Add Windows Control Flow Guard checks (/guard:cf).
Summary:
A new function pass (Transforms/CFGuard/CFGuard.cpp) inserts CFGuard checks on
indirect function calls, using either the check mechanism (X86, ARM, AArch64) or
or the dispatch mechanism (X86-64). The check mechanism requires a new calling
convention for the supported targets. The dispatch mechanism adds the target as
an operand bundle, which is processed by SelectionDAG. Another pass
(CodeGen/CFGuardLongjmp.cpp) identifies and emits valid longjmp targets, as
required by /guard:cf. This feature is enabled using the `cfguard` CC1 option.

Reviewers: thakis, rnk, theraven, pcc

Subscribers: ychen, hans, metalcanine, dmajor, tomrittervg, alex, mehdi_amini, mgorny, javed.absar, kristof.beyls, hiraditya, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65761
2019-10-28 15:19:39 +00:00
Amy Huang 64c1f6602a Revert "Add an instruction marker field to the ExtraInfo in MachineInstrs."
Reverting commit b85b4e5a6f due to some
buildbot failures/ out of memory errors.
2019-10-25 12:41:34 -07:00
Amy Huang b85b4e5a6f Add an instruction marker field to the ExtraInfo in MachineInstrs.
Summary:
Add instruction marker to MachineInstr ExtraInfo. This does almost the
same thing as Pre/PostInstrSymbols, except that it doesn't create a label until
printing instructions. This allows for labels to be put around instructions that
are deleted/duplicated somewhere.

Also undo the workaround in r375137.

Reviewers: rnk

Subscribers: MatzeB, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69136
2019-10-25 09:21:10 -07:00
Reid Kleckner 7bbe711fb1 Avoid including CodeView/SymbolRecord.h from MCStreamer.h
Move the types needed out so they can be forward declared instead.

llvm-svn: 375325
2019-10-19 01:44:09 +00:00
David Blaikie 2941cda5be DebugInfo: Move loclist base address from DwarfFile to DebugLocStream
There's no need to have more than one of these (there can be two
DwarfFiles - one for the .o, one for the .dwo - but only one loc/loclist
section (either in the .o or the .dwo) & certainly one per
DebugLocStream, which is currently singular in DwarfDebug)

llvm-svn: 375183
2019-10-17 23:02:19 +00:00
David Blaikie 3d737b642a DebugInfo: Remove unused parameter (from DwarfDebug.cpp:emitListsTableHeaderStart)
llvm-svn: 375180
2019-10-17 22:11:40 +00:00
Reid Kleckner fc69ad0988 [codeview] Workaround for PR43479, don't re-emit instr labels
Summary:
In the long run we should come up with another mechanism for marking
call instructions as heap allocation sites, and remove this workaround.
For now, we've had two bug reports about this, so let's apply this
workaround. SLH (the other client of instruction labels) probably has
the same bug, but the solution there is more likely to be to mark the
call instruction as not duplicatable, which doesn't work for debug info.

Reviewers: akhuang

Subscribers: aprantl, hiraditya, aganea, chandlerc, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69068

llvm-svn: 375137
2019-10-17 17:28:31 +00:00
Benjamin Kramer ce00cd6ae8 [AsmPrinter] Fix unused variable warning in Release builds. NFC.
llvm-svn: 374894
2019-10-15 14:23:11 +00:00
David Stenberg 1ae2d9a2bd [DebugInfo] Add a DW_OP_LLVM_entry_value operation
Summary:
Internally in LLVM's metadata we use DW_OP_entry_value operations with
the same semantics as DWARF; that is, its operand specifies the number
of bytes that the entry value covers.

At the time of emitting entry values we don't know the emitted size of
the DWARF expression that the entry value will cover. Currently the size
is hardcoded to 1 in DIExpression, and other values causes the verifier
to fail. As the size is 1, that effectively means that we can only have
valid entry values for registers that can be encoded in one byte, which
are the registers with DWARF numbers 0 to 31 (as they can be encoded as
single-byte DW_OP_reg0..DW_OP_reg31 rather than a multi-byte
DW_OP_regx). It is a bit confusing, but it seems like llvm-dwarfdump
will print an operation "correctly", even if the byte size is less than
that, which may make it seem that we emit correct DWARF for registers
with DWARF numbers > 31. If you instead use readelf for such cases, it
will interpret the number of specified bytes as a DWARF expression. This
seems like a limitation in llvm-dwarfdump.

As suggested in D66746, a way forward would be to add an internal
variant of DW_OP_entry_value, DW_OP_LLVM_entry_value, whose operand
instead specifies the number of operations that the entry value covers,
and we then translate that into the byte size at the time of emission.

In this patch that internal operation is added. This patch keeps the
limitation that a entry value can only be applied to simple register
locations, but it will fix the issue with the size operand being
incorrect for DWARF numbers > 31.

Reviewers: aprantl, vsk, djtodoro, NikolaPrica

Reviewed By: aprantl

Subscribers: jyknight, fedor.sergeev, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67492

llvm-svn: 374881
2019-10-15 11:31:21 +00:00
David Stenberg 284827f32b [DebugInfo] Add interface for pre-calculating the size of emitted DWARF
Summary:
DWARF's DW_OP_entry_value operation has two operands; the first is a
ULEB128 operand that specifies the size of the second operand, which is
a DWARF block. This means that we need to be able to pre-calculate and
emit the size of DWARF expressions before emitting them. There is
currently no interface for doing this in DwarfExpression, so this patch
introduces that.

When implementing this I initially thought about running through
DwarfExpression's emission two times; first with a temporary buffer to
emit the expression, in order to being able to calculate the size of
that emitted data. However, DwarfExpression is a quite complex state
machine, so I decided against that, as it seemed like the two runs could
get out of sync, resulting in incorrect size operands. Therefore I have
implemented this in a way that we only have to run DwarfExpression once.
The idea is to emit DWARF to a temporary buffer, for which it is
possible to query the size. The data in the temporary buffer can then be
emitted to DwarfExpression's main output.

In the case of DIEDwarfExpression, a temporary DIE is used. The values
are all allocated using the same BumpPtrAllocator as for all other DIEs,
and the values are then transferred to the real value list. In the case
of DebugLocDwarfExpression, the temporary buffer is implemented using a
BufferByteStreamer which emits to a buffer in the DwarfExpression
object.

Reviewers: aprantl, vsk, NikolaPrica, djtodoro

Reviewed By: aprantl

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67768

llvm-svn: 374879
2019-10-15 11:14:35 +00:00
David Stenberg d46ac44ecd Change Comments SmallVector to std::vector in DebugLocStream [NFC]
This changes the 32-element SmallVector to a std::vector. When building
a RelWithDebInfo clang-8 binary, the average size of the vector was
~10000, so it does not seem very beneficial or practical to use a small
vector for that.

The DWARFBytes SmallVector grows in the same way as Comments, so perhaps
that also should be changed to a purely dynamically allocated structure,
but that requires some more code changes, so I let that remain as a
SmallVector for now.

llvm-svn: 374871
2019-10-15 09:21:09 +00:00
David Stenberg 8535bed795 [DebugInfo] Fix truncation of call site immediates
Summary:
This addresses a bug in collectCallSiteParameters() where call site
immediates would be truncated from int64_t to unsigned.

This fixes PR43525.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: aprantl

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D68869

llvm-svn: 374770
2019-10-14 12:49:58 +00:00
David Blaikie de9aa37bf0 DebugInfo: Reduce the scope of some variables related to debug_ranges emission
Minor tidy up/NFC

llvm-svn: 374613
2019-10-11 23:51:24 +00:00
David Blaikie 289c45cc62 DebugInfo: Use base address selection entries for debug_loc
Unify the range and loc emission (for both DWARFv4 and DWARFv5 style lists) and take advantage of that unification to use strategic base addresses for loclists.

Differential Revision: https://reviews.llvm.org/D68620

llvm-svn: 374600
2019-10-11 21:52:41 +00:00
Reid Kleckner 9d8f0b3519 [codeview] Try to avoid emitting .cv_loc with line zero
Summary:
Visual Studio doesn't like it while stepping. It kicks you out of the
source view of the file being stepped through and tries to fall back to
the disassembly view.

Fixes PR43530

The fix is incomplete, because it's possible to have a basic block with
no source locations at all. In this case, we don't emit a .cv_loc, but
that will result in wrong stepping behavior in the debugger if the
layout predecessor of the location-less BB has an unrelated source
location. We could try harder to find a valid location that dominates or
post-dominates the current BB, but in general it's a dataflow problem,
and one still might not exist. I left a FIXME about this.

As an alternative, we might want to consider having the middle-end check
if its emitting codeview and get it to stop using line zero.

Reviewers: akhuang

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68747

llvm-svn: 374267
2019-10-10 01:06:01 +00:00
Jordan Rose fdaa742174 Second attempt to add iterator_range::empty()
Doing this makes MSVC complain that `empty(someRange)` could refer to
either C++17's std::empty or LLVM's llvm::empty, which previously we
avoided via SFINAE because std::empty is defined in terms of an empty
member rather than begin and end. So, switch callers over to the new
method as it is added.

https://reviews.llvm.org/D68439

llvm-svn: 373935
2019-10-07 18:14:24 +00:00
David Blaikie 2ac586c58f DebugInfo: Generalize rnglist emission as a precursor to reusing it for loclist emission
llvm-svn: 373663
2019-10-03 20:56:23 +00:00
David Blaikie 11e0bcf8a2 DebugInfo: Rename DebugLocStream::Entry::Begin/EndSym to just Begin/End
Brings this struct in line with the RangeSpan class so they might
eventually be used by common template code for generating range/loc
lists with less duplicate code.

llvm-svn: 373540
2019-10-02 22:58:02 +00:00
David Blaikie b677cb8dc7 DebugInfo: Simplify RangeSpan to be a plain struct
This is an effort to make RangeSpan and DebugLocStream::Entry more
similar to share code for their emission (to reuse the more complicated
code for using (& choosing when to use) base address selection entries,
etc).

It didn't seem like this struct was worth the complexity of
encapsulation - when the members could be initialized by the ctor to any
value (no validation) and the type is assignable (so there's no
mutability or other constraint being implemented by its interface).

llvm-svn: 373533
2019-10-02 22:27:24 +00:00
Simon Pilgrim 369d16a1c6 AsmPrinter - emitGlobalConstantFP - silence static analyzer null dereference warning. NFCI.
All the calls to emitGlobalConstantFP should provide a nonnull Type for the float.

llvm-svn: 373464
2019-10-02 13:08:46 +00:00
Simon Pilgrim c9129cea27 WinException::emitExceptHandlerTable - silence static analyzer dyn_cast<Function> null dereference warning. NFCI.
The static analyzer is warning about a potential null dereference, but we should be able to use cast<Function> directly and if not assert will fire for us.

llvm-svn: 373449
2019-10-02 11:48:32 +00:00
David Blaikie bfc68885d9 DebugInfo: Update support for detecting C++ language variants in debug info emission
llvm-svn: 373420
2019-10-02 01:39:48 +00:00
David Blaikie 38456776b3 DebugInfo: Simplify section label caching/usage
llvm-svn: 373273
2019-09-30 23:19:10 +00:00
Yuanfang Chen cc382cf727 [NewPM] Port MachineModuleInfo to the new pass manager.
Existing clients are converted to use MachineModuleInfoWrapperPass. The
new interface is for defining a new pass manager API in CodeGen.

Reviewers: fedor.sergeev, philip.pfaffe, chandlerc, arsenm

Reviewed By: arsenm, fedor.sergeev

Differential Revision: https://reviews.llvm.org/D64183

llvm-svn: 373240
2019-09-30 17:54:50 +00:00
Djordje Todorovic eb4c98ca3d [DebugInfo] Exclude memory location values as parameter entry values
Abandon describing of loaded values due to safety concerns. Loaded
values are described as derefed memory location at caller point.
At callee we can unintentionally change that memory location which
would lead to different entry being printed value before and after
the memory location clobbering. This problem is described in
llvm.org/PR43343.

Patch by Nikola Prica

Differential Revision: https://reviews.llvm.org/D67717

llvm-svn: 373089
2019-09-27 13:52:43 +00:00
Guillaume Chatelet 18f805a7ea [Alignment][NFC] Remove unneeded llvm:: scoping on Align types
llvm-svn: 373081
2019-09-27 12:54:21 +00:00
Xiangling Liao 3b808fb330 [AIX]Emit function descriptor csect in assembly
This patch emits the function descriptor csect for functions with definitions
under both 32-bit/64-bit mode on AIX.

Differential Revision: https://reviews.llvm.org/D66724

llvm-svn: 373009
2019-09-26 19:38:32 +00:00
Guillaume Chatelet 1ae7905fc8 [Alignment][NFC] DataLayout migration to llvm::Align
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: jholewinski, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67914

llvm-svn: 372596
2019-09-23 12:41:36 +00:00
Adrian Prantl 0779dffbd4 Remove the obsolete BlockByRefStruct flag from LLVM IR
DIFlagBlockByRefStruct is an unused DIFlag that originally was used by
clang to express (Objective-)C block captures in debug info. For the
last year Clang has been emitting complex DIExpressions to describe
block captures instead, which makes all the code supporting this flag
redundant.

This patch removes the flag and all supporting "dead" code, so we can
reuse the bit for something else in the future.

Since this only affects debug info generated by Clang with the block
extension this mostly affects Apple platforms and I don't have any
bitcode compatibility concerns for removing this. The Verifier will
reject debug info that uses the bit and thus degrade gracefully when
LTO'ing older bitcode with a newer compiler.

rdar://problem/44304813

Differential Revision: https://reviews.llvm.org/D67453

llvm-svn: 372272
2019-09-18 22:38:56 +00:00
Guillaume Chatelet 35b4b403b4 [Alignment][NFC] Use Align::None instead of 1
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: sdardis, nemanjai, hiraditya, kbarton, jrtc27, MaskRay, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67704

llvm-svn: 372230
2019-09-18 15:40:20 +00:00
Francis Visoiu Mistrih ba2e752c52 [Remarks] Allow the RemarkStreamer to be used directly with a stream
The filename in the RemarkStreamer should be optional to allow clients
to stream remarks to memory or to existing streams.

This introduces a new overload of `setupOptimizationRemarks`, and avoids
enforcing the presence of a filename at different places.

llvm-svn: 372195
2019-09-18 01:04:45 +00:00
Guillaume Chatelet af11cc7eb5 [Alignment] Move OffsetToAlignment to Alignment.h
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet, JDevlieghere, alexshap, rupprecht, jhenderson

Subscribers: sdardis, nemanjai, hiraditya, kbarton, jakehehrlich, jrtc27, MaskRay, atanasyan, jsji, seiya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D67499

llvm-svn: 371742
2019-09-12 15:20:36 +00:00
Vedant Kumar 0b91333d59 [DWARF] Emit call site parameter info when tuning for lldb
Emit debug entry values using standard DWARF5 opcodes when the debugger
tuning is set to lldb.

Differential Revision: https://reviews.llvm.org/D67410

llvm-svn: 371666
2019-09-11 21:23:39 +00:00
Guillaume Chatelet 97264366fb [Alignment][NFC] use llvm::Align for AsmPrinter::EmitAlignment
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: dschuff, sdardis, nemanjai, hiraditya, kbarton, jrtc27, MaskRay, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67443

llvm-svn: 371616
2019-09-11 13:37:35 +00:00
Guillaume Chatelet 48904e9452 [Alignment] Use llvm::Align in MachineFunction and TargetLowering - fixes mir parsing
Summary:
This catches malformed mir files which specify alignment as log2 instead of pow2.
See https://reviews.llvm.org/D65945 for reference,

This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: MatzeB, qcolombet, dschuff, arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67433

llvm-svn: 371608
2019-09-11 11:16:48 +00:00
David Stenberg 5a583665f4 [DebugInfo][X86] Describe call site values for zero-valued imms
Summary:
Add zero-materializing XORs to X86's describeLoadedValue() hook in order
to produce call site values.

I have had to change the defs logic in collectCallSiteParameters() a bit
to be able to describe the XORs. The XORs implicitly define $eflags,
which would cause them to never be considered, due to a guard condition
that I->getNumDefs() is one. I have changed that condition so that we
now only consider instructions where a forwarded register overlaps with
the instruction's single explicit define. We still need to collect the implicit
defines of other forwarded registers to remove them from the work list.
I'm not sure how to move towards supporting instructions with multiple
explicit defines, cases where forwarded register are implicitly defined,
and/or cases where an instruction produces values for multiple forwarded
registers. Perhaps the describeLoadedValue() hook should take a register
argument, and we then leave it up to the hook to describe the loaded
value in that register? I have not yet encountered a situation where
that would be necessary though.

Reviewers: aprantl, vsk, djtodoro, NikolaPrica

Reviewed By: vsk

Subscribers: ychen, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67225

llvm-svn: 371333
2019-09-08 14:22:06 +00:00
David Stenberg 8b70139e95 [NFC] Make the describeLoadedValue() hook return machine operand objects
Summary:
This changes the ParamLoadedValue pair which the describeLoadedValue()
hook returns so that MachineOperand objects are returned instead of
pointers.

When describing call site values we may need to describe operands which
are not part of the instruction. One such example is zero-materializing
XORs on x86, which I have implemented support for in a child revision.
Instead of having to return a pointer to an operand stored somewhere
outside the instruction, start returning objects directly instead, as
that simplifies the code.

The MachineOperand class only holds POD members, and on x86-64 it is 32
bytes large. That combined with copy elision means that the overhead of
returning a machine operand object from the hook does not become very
large.

I benchmarked this on a 8-thread i7-8650U machine with 32 GB RAM. The
benchmark consisted of building a clang 8.0 binary configured with:

  -DCMAKE_BUILD_TYPE=RelWithDebInfo \
  -DLLVM_TARGETS_TO_BUILD=X86 \
  -DLLVM_USE_SANITIZER=Address \
  -DCMAKE_CXX_FLAGS="-Xclang -femit-debug-entry-values -stdlib=libc++"

The average wall clock time increased by 4 seconds, from 62:05 to
62:09, which is an 0.1% increase.

Reviewers: aprantl, vsk, djtodoro, NikolaPrica

Reviewed By: vsk

Subscribers: hiraditya, ychen, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67261

llvm-svn: 371332
2019-09-08 14:05:10 +00:00
Bjorn Pettersson 2b698a13a1 [DwarfExpression] Disallow some rewrites to avoid undefined behavior
Summary:
The value operand in DW_OP_plus_uconst/DW_OP_constu value can be
large (it uses uint64_t as representation internally in LLVM).
This means that in the uint64_t to int conversions, previously done
by DwarfExpression::addMachineRegExpression, could lose information.
Also, the negation done in "-Offset" was undefined behavior in case
Offset was exactly INT_MIN.

To avoid the above problems, we now avoid transformation like
 [Reg, DW_OP_plus_uconst, Offset] --> [DW_OP_breg, Offset]
and
 [Reg, DW_OP_constu, Offset, DW_OP_plus]  --> [DW_OP_breg, Offset]
when Offset > INT_MAX.

And we avoid to transform
 [Reg, DW_OP_constu, Offset, DW_OP_minus] --> [DW_OP_breg,-Offset]
when Offset > INT_MAX+1.

The patch also adjusts DwarfCompileUnit::constructVariableDIEImpl
to make sure that "DW_OP_constu, Offset, DW_OP_minus" is used
instead of "DW_OP_plus_uconst, Offset" when creating DIExpressions
with negative frame index offsets.

Notice that this might just be the tip of the iceberg. There
are lots of fishy handling related to these constants. I think both
DIExpression::appendOffset and DIExpression::extractIfOffset may
trigger undefined behavior for certain values.

Reviewers: sdesmalen, rnk, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: jholewinski, aprantl, hiraditya, ychen, uabelho, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67263

llvm-svn: 371304
2019-09-07 11:40:10 +00:00
Guillaume Chatelet aff45e4b23 [LLVM][Alignment] Make functions using log of alignment explicit
Summary:
This patch renames functions that takes or returns alignment as log2, this patch will help with the transition to llvm::Align.
The renaming makes it explicit that we deal with log(alignment) instead of a power of two alignment.
A few renames uncovered dubious assignments:

 - `MirParser`/`MirPrinter` was expecting powers of two but `MachineFunction` and `MachineBasicBlock` were using deal with log2(align). This patch fixes it and updates the documentation.
 - `MachineBlockPlacement` exposes two flags (`align-all-blocks` and `align-all-nofallthru-blocks`) supposedly interpreted as power of two alignments, internally these values are interpreted as log2(align). This patch updates the documentation,
 - `MachineFunctionexposes` exposes `align-all-functions` also interpreted as power of two alignment, internally this value is interpreted as log2(align). This patch updates the documentation,

Reviewers: lattner, thegameg, courbet

Subscribers: dschuff, arsenm, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, Jim, s.egerton, llvm-commits, courbet

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65945

llvm-svn: 371045
2019-09-05 10:00:22 +00:00
Shafik Yaghmour 90e00bd8f3 Debug Info: Support for DW_AT_export_symbols for anonymous structs
This implements the DWARF 5 feature described in:

http://dwarfstd.org/ShowIssue.php?issue=141212.1

To support recognizing anonymous structs:

  struct A {
    struct { // Anonymous struct
        int y;
    };
  } a

This patch adds support for the new flag in constructTypeDIE(...) and test to verify this change.

Differential Revision: https://reviews.llvm.org/D66605

llvm-svn: 369969
2019-08-26 20:59:44 +00:00
Vedant Kumar 58a0714885 [DWARF] Rename getDwarf5OrGNUCallSite{Attr,Tag}, NFC
llvm-svn: 369967
2019-08-26 20:53:34 +00:00
Vedant Kumar 533dd0214c [DWARF] Pick the DWARF5 OP_entry_value opcode on Darwin
Use the GNU extension for OP_entry_value consistently (i.e. whenever GNU
extensions are used for TAG_call_site).

llvm-svn: 369966
2019-08-26 20:53:12 +00:00
Xing Xue ef039a3ccd [PowerPC][AIX] Adds support for writing the .data section in assembly files
Summary:
Adds support for generating the .data section in assembly files for global variables with a non-zero initialization. The support for writing the .data section in XCOFF object files will be added in a follow-on patch. Any relocations are not included in this patch.

Reviewers: hubert.reinterpretcast, sfertile, jasonliu, daltenty, Xiangling_L

Reviewed by: hubert.reinterpretcast

Subscribers: nemanjai, hiraditya, kbarton, MaskRay, jsji, wuzish, shchenz, DiggerLin, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66154

llvm-svn: 369869
2019-08-25 15:17:25 +00:00
Nilanjana Basu 7da6f432d8 Removing block comments from CodeView records in assembly files & related code cleanup
llvm-svn: 369860
2019-08-25 01:09:11 +00:00
Peter Collingbourne 2452d7030b IR. Change strip* family of functions to not look through aliases.
I noticed another instance of the issue where references to aliases were
being replaced with aliasees, this time in InstCombine. In the instance that
I saw it turned out to be only a QoI issue (a symbol ended up being missing
from the symbol table due to the last reference to the alias being removed,
preventing HWASAN from symbolizing a global reference), but it could easily
have manifested as incorrect behaviour.

Since this is the third such issue encountered (previously: D65118, D65314)
it seems to be time to address this common error/QoI issue once and for all
and make the strip* family of functions not look through aliases.

Includes a test for the specific issue that I saw, but no doubt there are
other similar bugs fixed here.

As with D65118 this has been tested to make sure that the optimization isn't
load bearing. I built Clang, Chromium for Linux, Android and Windows as well
as the test-suite and there were no size regressions.

Differential Revision: https://reviews.llvm.org/D66606

llvm-svn: 369697
2019-08-22 19:56:14 +00:00
Francis Visoiu Mistrih 5b5ee61b5f [MachO][TLOF] Use hasLocalLinkage to determine if indirect symbol is local
Local symbols in the indirect symbol table contain the value
`INDIRECT_SYMBOL_LOCAL` and the corresponding __pointers entry must
contain the address of the target.

In r349060, I added support for local symbols in the indirect symbol
table, which was checking if the symbol `isDefined` && `!isExternal` to
determine if the symbol is local or not.

It turns out that `isDefined` will return false if the user of the
symbol comes before its definition, and we'll again generate .long 0
which will be the symbol at the adress 0x0.

Instead of doing that, use GlobalValue::hasLocalLinkage() to check if
the symbol is local.

Differential Revision: https://reviews.llvm.org/D66563

llvm-svn: 369671
2019-08-22 16:59:00 +00:00
Nilanjana Basu ac3851c434 Improving CodeView debug info type record's inline comments
llvm-svn: 369533
2019-08-21 15:19:58 +00:00
Karl-Johan Karlsson 40da6be2bd [AsmPrinter] Remove const qualifier from EmitBasicBlockStart.
Overriders may want to modify state in it. AMDGPU wants
to, but has to make its members mutable in order to do so.

Besides, EmitBasicBlockEnd is not const, so why should
Start be?

Patch by Bevin Hansson.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D66341

llvm-svn: 369325
2019-08-20 05:13:57 +00:00
Daniel Sanders 0c47611131 Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
2019-08-15 19:22:08 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Taewook Oh df7022825c [DebugInfo] Consider debug label scope has an extra lexical block file
Summary: There are places where a case that debug label scope has an extra lexical block file is not considered properly. The modified test won't pass without this patch.

Reviewers: aprantl, HsiangKai

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66187

llvm-svn: 368891
2019-08-14 17:58:45 +00:00
Fangrui Song 8caa0aaa4d [AsmPrinter] Delete redundant .type foo, @function when emitting an ifunc
In MCAsmStreamer:

.type foo,@function   # <--- this is redundant
.type foo,@gnu_indirect_function

In MCELFStreamer, the latter STT_GNU_IFUNC overrides STT_FUNC.

llvm-svn: 368823
2019-08-14 10:30:27 +00:00
Bill Wendling 1b10438875 [MC] Don't recreate a label if it's already used
Summary:
This patch keeps track of MCSymbols created for blocks that were
referenced in inline asm. It prevents creating a new symbol which
doesn't refer to the block.

Inline asm may have a reference to a label. The asm parser however
doesn't recognize it as a label and tries to create a new symbol. The
result being that instead of the original symbol (e.g. ".Ltmp0") the
parser replaces it in the inline asm with the new one (e.g. ".Ltmp00")
without updating it in the symbol table. So the machine basic block
retains the "old" symbol (".Ltmp0"), but the inline asm uses the new one
(".Ltmp00").

Reviewers: nickdesaulniers, craig.topper

Subscribers: nathanchance, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65304

llvm-svn: 368477
2019-08-09 20:16:31 +00:00
Igor Kudrin f26a70a5e7 Switch LLVM to use 64-bit offsets (2/5)
This updates all libraries and tools in LLVM Core to use 64-bit offsets
which directly or indirectly come to DataExtractor.

Differential Revision: https://reviews.llvm.org/D65638

llvm-svn: 368014
2019-08-06 10:49:40 +00:00
Nilanjana Basu da60fc813c Changing representation of .cv_def_range directives in Codeview debug info assembly format for better readability
llvm-svn: 367867
2019-08-05 14:16:58 +00:00
Nilanjana Basu b5e4d7de17 Revert "Changing representation of .cv_def_range directives in Codeview debug info assembly format for better readability"
This reverts commit a885afa9fa.

llvm-svn: 367861
2019-08-05 13:55:21 +00:00
Nilanjana Basu a885afa9fa Changing representation of .cv_def_range directives in Codeview debug info assembly format for better readability
llvm-svn: 367850
2019-08-05 13:11:51 +00:00
Eric Christopher 5fb56b1966 Temporarily Revert "Changing representation of cv_def_range directives in Codeview debug info assembly format for better readability"
This is breaking bots and the author asked me to revert.

This reverts commit 367704.

llvm-svn: 367707
2019-08-02 19:10:37 +00:00
Nilanjana Basu 1c67521591 Changing representation of cv_def_range directives in Codeview debug info assembly format for better readability
llvm-svn: 367704
2019-08-02 18:44:39 +00:00
Eric Christopher 5a00b0772a Temporarily revert "Changes to improve CodeView debug info type record inline comments"
due to a sanitizer failure.

This reverts commit 367623.

llvm-svn: 367640
2019-08-02 01:05:47 +00:00
Daniel Sanders 2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC
llvm-svn: 367633
2019-08-01 23:27:28 +00:00
Nilanjana Basu ac7e5788ca Changes to improve CodeView debug info type record inline comments
Signed-off-by: Nilanjana Basu <nilanjana.basu87@gmail.com>
llvm-svn: 367623
2019-08-01 22:05:14 +00:00
Eric Christopher 36fb93982f Fix unused variable warning for non-assert builds.
llvm-svn: 367482
2019-07-31 21:02:03 +00:00
Djordje Todorovic b9973f87c6 Reland "[DwarfDebug] Dump call site debug info"
The build failure found after the rL365467 has been
resolved.

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 367446
2019-07-31 16:51:28 +00:00
Francis Visoiu Mistrih 2d8fdcae96 Reland: [Remarks] Add support for serializing metadata for every remark streamer
This allows every serializer format to implement metaSerializer() and
return the corresponding meta serializer.

Original llvm-svn: 366946
Reverted llvm-svn: 367004

This fixes the unit tests on Windows bots.

llvm-svn: 367078
2019-07-26 01:33:30 +00:00
Simon Pilgrim 55fd57ba95 Revert rL366946 : [Remarks] Add support for serializing metadata for every remark streamer
This allows every serializer format to implement metaSerializer() and
return the corresponding meta serializer.
........
Fix windows build bots
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-win-fast
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win

llvm-svn: 367004
2019-07-25 10:20:39 +00:00
Francis Visoiu Mistrih 62388e3846 [Remarks] Add support for serializing metadata for every remark streamer
This allows every serializer format to implement metaSerializer() and
return the corresponding meta serializer.

llvm-svn: 366946
2019-07-24 21:29:44 +00:00
Francis Visoiu Mistrih ff4b515a77 [Remarks][NFC] Rename remarks::Serializer to remarks::RemarkSerializer
llvm-svn: 366939
2019-07-24 19:47:57 +00:00
Nick Desaulniers 4e9196ebcb Revert "Use the MachineBasicBlock symbol for a callbr target"
This reverts commit r366523/ccbffefccaff42b0d094c9ef0f49fc3e8c8456ea.

Two regressions were immediately reported:
- https://github.com/ClangBuiltLinux/linux/issues/614
- https://github.com/ClangBuiltLinux/linux/issues/615

Reported-by: nathanchance
llvm-svn: 366600
2019-07-19 18:18:02 +00:00
Bill Wendling ccbffefcca Use the MachineBasicBlock symbol for a callbr target
Summary:
Inline asm doesn't use labels when compiled as an object file. Therefore, we
shouldn't create one for the (potential) callbr destination. Instead, use the
symbol for the MachineBasicBlock.

Reviewers: nickdesaulniers, craig.topper

Reviewed By: nickdesaulniers

Subscribers: xbolva00, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64888

llvm-svn: 366523
2019-07-19 01:10:28 +00:00
Amy Huang f332fe642c [COFF] Change a variable type to be const in the HeapAllocSite map.
llvm-svn: 366479
2019-07-18 18:22:52 +00:00
Nilanjana Basu 4e22770219 Changes to display code view debug info type records in hex format
llvm-svn: 366390
2019-07-17 23:43:58 +00:00
Nilanjana Basu 6e4076699c Adding inline comments to code view type record directives for better readability
llvm-svn: 366372
2019-07-17 21:01:12 +00:00
Alex Bradbury ab009a602e [AsmPrinter] Make the encoding of call sites in .gcc_except_table configurable and use for RISC-V
The original behavior was to always emit the offsets to each call site in the
call site table as uleb128 values, however on some architectures (eg RISCV)
these uleb128 offsets into the code cannot always be resolved until link time
(because relaxation will invalidate any calculated offsets), and there are no
appropriate relocations for uleb128 values. As a consequence it needs to be
possible to specify an alternative.

This also switches RISCV to use DW_EH_PE_udata4 for call side encodings in
.gcc_except_table

Differential Revision: https://reviews.llvm.org/D63415
Patch by Edward Jones.

llvm-svn: 366329
2019-07-17 14:00:35 +00:00
David Blaikie 40580d36c4 DWARF: Skip zero column for inline call sites
D64033 <https://reviews.llvm.org/D64033> added DW_AT_call_column for
inline sites. However, that change wasn't aware of "-gno-column-info".
To avoid adding column info when "-gno-column-info" is used, now
DW_AT_call_column is only added when we have non-zero column (when
"-gno-column-info" is used, column will be zero).

Patch by Wenlei He!

Differential Revision: https://reviews.llvm.org/D64784

llvm-svn: 366264
2019-07-16 21:15:19 +00:00
Francis Visoiu Mistrih cc909812a3 [Remarks][NFC] Combine ParserFormat and SerializerFormat
It's useless to have both.

llvm-svn: 366216
2019-07-16 15:24:59 +00:00
Jonas Devlieghere 83264b3580 [DebugInfo] Add column info for inline sites
The column field is missing for all inline sites, currently it's always
zero. This changes populates DW_AT_call_column field for inline sites.
Test case modified to cover this change.

Patch by: Wenlei He

Differential revision: https://reviews.llvm.org/D64033

llvm-svn: 365945
2019-07-12 19:25:45 +00:00
Djordje Todorovic 0739ccd3b5 Revert "[DwarfDebug] Dump call site debug info"
A build failure was found on the SystemZ platform.

This reverts commit 9e7e73578e54cd22b3c7af4b54274d743b6607cc.

llvm-svn: 365886
2019-07-12 09:45:12 +00:00
Tim Northover 67828edbbd OpaquePtr: switch to GlobalValue::getValueType in a few places. NFC.
llvm-svn: 365770
2019-07-11 13:13:02 +00:00
Simon Pilgrim 480e8ad217 [CodeGen] AccelTable - remove non-constexpr (MSVC) Atom defs
Now that we've dropped VS2015 support (D64326) we can enable the constexpr variables on MSVC builds as VS2017+ correctly handles them

llvm-svn: 365477
2019-07-09 13:07:48 +00:00
Djordje Todorovic c1e0ea9765 [NFC][AsmPrinter] Fix the formatting for the rL365467
In addition, fix the build failure for the 'unused'
variable. The variable was used inside the 'LLVM_DEBUG()'.

llvm-svn: 365469
2019-07-09 12:06:21 +00:00
Djordje Todorovic 01eaae6dd1 [DwarfDebug] Dump call site debug info
Dump the DWARF information about call sites and call site parameters into
debug info sections.

The patch also provides an interface for the interpretation of instructions
that could load values of a call site parameters in order to generate DWARF
about the call site parameters.

([13/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 365467
2019-07-09 11:33:56 +00:00
Djordje Todorovic 12aca5de02 Reland "[LiveDebugValues] Emit the debug entry values"
Emit replacements for clobbered parameters location if the parameter
has unmodified value throughout the funciton. This is basic scenario
where we can use the debug entry values.

([12/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D58042

llvm-svn: 365444
2019-07-09 08:36:34 +00:00
Nilanjana Basu faed8516e4 Changing CodeView debug info type record representation in assembly files to make it more human-readable & editable & fixing bug introduced in r364987
llvm-svn: 365417
2019-07-09 01:11:02 +00:00
Reid Kleckner 2f07c2e9d9 Standardize on MSVC behavior for triples with no environment
Summary:
This makes it so that IR files using triples without an environment work
out of the box, without normalizing them.

Typically, the MSVC behavior is more desirable. For example, it tends to
enable things like constant merging, use of associative comdats, etc.

Addresses PR42491

Reviewers: compnerd

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64109

llvm-svn: 365387
2019-07-08 21:05:20 +00:00
Nilanjana Basu c0b557744a Revert Changing CodeView debug info type record representation in assembly files to make it more human-readable & editable
This reverts r364982 (git commit 2082bf28eb)

llvm-svn: 364987
2019-07-03 00:51:49 +00:00
Nilanjana Basu 2082bf28eb Changing CodeView debug info type record representation in assembly files to make it more human-readable & editable
llvm-svn: 364982
2019-07-03 00:26:23 +00:00
Nilanjana Basu 8b7a0baa20 Testing commit access through minor formatting change
llvm-svn: 364843
2019-07-01 20:27:37 +00:00
Djordje Todorovic a0d45058eb [DWARF] Handle the DW_OP_entry_value operand
Add the IR and the AsmPrinter parts for handling of the DW_OP_entry_values
DWARF operation.

([11/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60866

llvm-svn: 364542
2019-06-27 13:52:34 +00:00
Djordje Todorovic 59b39faa18 [IR] Add DISuprogram and DIE for a func decl
A unique DISubprogram may be attached to a function declaration used for
call site debug info.

([6/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60713

llvm-svn: 364500
2019-06-27 06:07:41 +00:00
Matt Arsenault e3a676e9ad CodeGen: Introduce a class for registers
Avoids using a plain unsigned for registers throughoug codegen.
Doesn't attempt to change every register use, just something a little
more than the set needed to build after changing the return type of
MachineOperand::getReg().

llvm-svn: 364191
2019-06-24 15:50:29 +00:00
Amy Huang 7fac5c8d94 Store a pointer to the return value in a static alloca and let the debugger use that
as the variable address for NRVO variables.

Subscribers: hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D63361

llvm-svn: 363952
2019-06-20 17:15:21 +00:00
Peter Collingbourne fb9ce100d1 hwasan: Add a tag_offset DWARF attribute to instrumented stack variables.
The goal is to improve hwasan's error reporting for stack use-after-return by
recording enough information to allow the specific variable that was accessed
to be identified based on the pointer's tag. Currently we record the PC and
lower bits of SP for each stack frame we create (which will eventually be
enough to derive the base tag used by the stack frame) but that's not enough
to determine the specific tag for each variable, which is the stack frame's
base tag XOR a value (the "tag offset") that is unique for each variable in
a function.

In IR, the tag offset is most naturally represented as part of a location
expression on the llvm.dbg.declare instruction. However, the presence of the
tag offset in the variable's actual location expression is likely to confuse
debuggers which won't know about tag offsets, and moreover the tag offset
is not required for a debugger to determine the location of the variable on
the stack, so at the DWARF level it is represented as an attribute so that
it will be ignored by debuggers that don't know about it.

Differential Revision: https://reviews.llvm.org/D63119

llvm-svn: 363635
2019-06-17 23:39:41 +00:00
David Blaikie 4129e3e0f8 DebugInfo: Include enumerators in pubnames
This is consistent with GCC's behavior (which is the defacto standard
for pubnames). Though I find the presence of enumerators from enum
classes to be a bit confusing, possibly a bug on GCC's end (since they
can't be named unqualified, unlike the other names - and names nested in
classes don't go in pubnames, for instance - presumably because one must
name the class first & that's enough to limit the scope of the search)

llvm-svn: 363349
2019-06-14 01:58:56 +00:00
Amy Huang 49275272e3 Use fully qualified name when printing S_CONSTANT records
Summary:
Before it was using the fully qualified name only for static data members.
Now it does for all variable names to match MSVC.

Reviewers: rnk

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63012

llvm-svn: 363335
2019-06-13 22:53:43 +00:00
Nikola Prica 076ae0d2e2 [DebugInfo] Move Value struct out of DebugLocEntry as DbgValueLoc (NFC)
Since the DebugLocEntry::Value is used as part of DwarfDebug and
DebugLocEntry make it as the separate class.

Reviewers: aprantl, dstenb

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D63213

llvm-svn: 363246
2019-06-13 10:23:26 +00:00
Jeremy Morse 181bf0cefb [DebugInfo] Use FrameDestroy to extend stack locations to end-of-function
We aim to ignore changes in variable locations during the prologue and
epilogue of functions, to avoid using space documenting location changes
that aren't visible. However in D61940 / r362951 this got ripped out as
the previous implementation was unsound.

Instead, use the FrameDestroy flag to identify when we're in the epilogue
of a function, and ignore variable location changes accordingly. This fits
in with existing code that examines the FrameSetup flag.

Some variable locations get shuffled in modified tests as they now cover
greater ranges, which is what would be expected. Some additional
single-location variables are generated too. Two tests are un-xfailed,
they were only xfailed due to r362951 deleting functionality they depended
on.

Apparently some out-of-tree backends don't accurately maintain FrameDestroy
flags -- if you're an out-of-tree maintainer and see changes in variable
locations disappear due to a faulty FrameDestroy flag, it's safe to back
this change out. The impact is just slightly more debug info than necessary.

Differential Revision: https://reviews.llvm.org/D62314

llvm-svn: 363245
2019-06-13 10:03:17 +00:00
Jeremy Morse bcff417292 [DebugInfo] Terminate all location-lists at end of block
This commit reapplies r359426 (which was reverted in r360301 due to
performance problems) and rolls in D61940 to address the performance problem.
I've combined the two to avoid creating a span of slow-performance, and to
ease reverting if more problems crop up.

The summary of D61940: This patch removes the "ChangingRegs" facility in
DbgEntityHistoryCalculator, as its overapproximate nature can produce incorrect
variable locations. An unchanging register doesn't mean a variable doesn't
change its location.

The patch kills off everything that calculates the ChangingRegs vector.
Previously ChangingRegs spotted epilogues and marked registers as unchanging if
they weren't modified outside the epilogue, increasing the chance that we can
emit a single-location variable record. Without this feature,
debug-loc-offset.mir and pr19307.mir become temporarily XFAIL. They'll be
re-enabled by D62314, using the FrameDestroy flag to identify epilogues, I've
split this into two steps as FrameDestroy isn't necessarily supported by all
backends.

The logic for terminating variable locations at the end of a basic block now
becomes much more enjoyably simple: we just terminate them all.

Other test changes: inlined-argument.ll becomes XFAIL, but for a longer term.
The current algorithm for detecting that a variable has a single-location
doesn't work in this scenario (inlined function in multiple blocks), only other
bugs were making this test work. fission-ranges.ll gets slightly refreshed too,
as the location of "p" is now correctly determined to be a single location.

Differential Revision: https://reviews.llvm.org/D61940

llvm-svn: 362951
2019-06-10 15:23:46 +00:00
Nikola Prica abc1dff7e4 [DebugInfo] More strict debug range for stack variables
Variable's stack location can stretch longer than it should. If a
variable is placed at the stack in a some nested basic block its range
can be calculated to be up to the next occurrence of the variable's
DBG_VALUE, or up to the end of the function, thus covering a basic
blocks that should not be included in the variable’s location range.
This happens because the DbgEntityHistoryCalculator ends register
locations at the end of a basic block only if the variable’s location
register has been changed throughout the function, which is not the
case for the register used to reference stack objects.

This patch also tries to produce a single value location if the location
list builder managed to merge all the locations into one.

Reviewers: aprantl, dstenb, jmorse

Reviewed By: aprantl, dstenb, jmorse

Subscribers: djtodoro, ivanbaev, asowda

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D61600

llvm-svn: 362923
2019-06-10 08:41:06 +00:00
Francis Visoiu Mistrih 6ada11f134 [Remarks][NFC] Move the serialization to lib/Remarks
Separate the remark serialization to YAML from the LLVM Diagnostics.

This adds a new serialization abstraction: remarks::Serializer. It's
completely independent from lib/IR and it provides an easy way to
replace YAML by providing a new remarks::Serializer.

Differential Revision: https://reviews.llvm.org/D62632

llvm-svn: 362160
2019-05-30 21:45:59 +00:00
Amy Huang 325003be02 CodeView - add static data members to global variable debug info.
Summary:
Add static data members to IR debug info's list of global variables
so that they are emitted as S_CONSTANT records.

Related to https://bugs.llvm.org/show_bug.cgi?id=41615.

Reviewers: rnk

Subscribers: aprantl, cfe-commits, llvm-commits, thakis

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D62167

llvm-svn: 362038
2019-05-29 21:45:34 +00:00
Peter Collingbourne 31fda09b2d Add IR support, ELF section and user documentation for partitioning feature.
The partitioning feature was proposed here:
http://lists.llvm.org/pipermail/llvm-dev/2019-February/130583.html

This is mostly just documentation. The feature itself will be contributed
in subsequent patches.

Differential Revision: https://reviews.llvm.org/D60242

llvm-svn: 361923
2019-05-29 03:29:01 +00:00
David Stenberg 5d0e6b6755 Stop undef fragments from closing non-overlapping fragments
Summary:
When DwarfDebug::buildLocationList() encountered an undef debug value,
it would truncate all open values, regardless if they were overlapping or
not. This patch fixes so that it only does that for overlapping fragments.

This change unearthed a bug that I had introduced in D57511,
which I have fixed in this patch. The code in DebugHandlerBase that
changes labels for parameter debug values could break DwarfDebug's
assumption that the labels for the entries in the debug value history
are monotonically increasing. Before this patch, that bug could result
in location list entries whose ending address was lower than the
beginning address, and with the changes for undef debug values that this
patch introduces it could trigger an assertion, due to attempting to
emit location list entries with empty ranges. A reproducer for the bug
is added in param-reg-const-mix.mir.

Reviewers: aprantl, jmorse, probinson

Reviewed By: aprantl

Subscribers: javed.absar, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D62379

llvm-svn: 361820
2019-05-28 13:23:25 +00:00
Shoaib Meenai 87226a7202 [AsmPrinter] Treat a narrowing PtrToInt like Trunc
When printing assembly for PtrToInt, AsmPrinter::lowerConstant
incorrectly assumed that if PtrToInt was not converting to an
int with exactly the same number of bits, it must be widening
to a larger int. But this isn't necessarily true; PtrToInt can
also shrink the size, which is useful when you want to produce
a known 32-bit pointer on a 64-bit platform (on x86_64 ELF
this yields a R_X86_64_32 relocation).

The old behavior of falling through to the widening case for a
narrowing PtrToInt yields bogus assembly code like this, which
fails to assemble because the no-op bit and it accidentally
creates is not a valid relocation:

```
        .long   a&-1
```

The fix is to treat a narrowing PtrToInt exactly the same as
it already treats Trunc: just emit the expression and let
the assembler deal with truncating it in the appropriate way.

Patch by Mat Hostetter <mjh@fb.com>.

Differential Revision: https://reviews.llvm.org/D61325

llvm-svn: 361508
2019-05-23 16:29:09 +00:00
Petar Jovanovic ff47d83e78 [DwarfExpression] Refactor dwarf expression (NFC)
Refactor location description kind in order to be easier for extensions
(needed for D60866).
In addition, cut off some bits from the other class fields.

Patch by Djordje Todorovic.

Differential Revision: https://reviews.llvm.org/D62002

llvm-svn: 361480
2019-05-23 10:37:13 +00:00
Amy Huang c2029068bc Emit global variables as S_CONSTANT records for codeview debug info.
Summary:
This emits S_CONSTANT records for global variables.
Currently this emits records for the global variables already being tracked in the
LLVM IR metadata, which are just constant global variables; we'll also want S_CONSTANTs
for static data members and enums.

Related to https://bugs.llvm.org/show_bug.cgi?id=41615

Reviewers: rnk

Subscribers: aprantl, hiraditya, llvm-commits, thakis

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61926

llvm-svn: 360948
2019-05-16 22:28:52 +00:00
Reid Kleckner 4882490349 [codeview] Fix SDNode representation of annotation labels
Before this change, they were erroneously constructed with the EH_LABEL
SDNode opcode, which caused other passes to interact with them in
incorrect ways. See the FIXME about fastisel that this addresses in the
existing test case.

Fixes PR41890

llvm-svn: 360818
2019-05-15 21:46:05 +00:00
Fangrui Song f4dfd63c74 [IR] Disallow llvm.global_ctors and llvm.global_dtors of the 2-field form in textual format
The 3-field form was introduced by D3499 in 2014 and the legacy 2-field
form was planned to be removed in LLVM 4.0

For the textual format, this patch migrates the existing 2-field form to
use the 3-field form and deletes the compatibility code.
test/Verifier/global-ctors-2.ll checks we have a friendly error message.

For bitcode, lib/IR/AutoUpgrade UpgradeGlobalVariables will upgrade the
2-field form (add i8* null as the third field).

Reviewed By: rnk, dexonsmith

Differential Revision: https://reviews.llvm.org/D61547

llvm-svn: 360742
2019-05-15 02:35:32 +00:00
Fangrui Song 2f6ef2fc92 DWARF v5: emit DW_AT_addr_base if DW_AT_low_pc references .debug_addr
The condition !AddrPool.empty() is tested before attachRangesOrLowHighPC(), which may add an entry to AddrPool. We emit DW_AT_low_pc (DW_FORM_addrx) but may incorrectly omit DW_AT_addr_base for LineTablesOnly. This can be easily reproduced:

clang -gdwarf-5 -gmlt -c a.cc

Fix this by moving !AddrPool.empty() below.

This was discovered while investigating an lld crash (fixed by D61889) on such object files: ld.lld --gdb-index a.o

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D61891

llvm-svn: 360678
2019-05-14 14:37:26 +00:00
David Blaikie 7598b71488 DebugInfo: Only move types out of type units if they're named or type united
Follow up to r359122, after a bug was reported in it - the original
change too aggressively tried to move related types out of type units,
which included unnamed types (like array types) which can't reasonably
be declared-but-not-defined.

A step beyond that is that some types in type units can be anonymous, if
they are types with a name for linkage purposes (eg: "typedef struct { }
x;"). So ensure those don't get turned into plain declarations (without
signatures) because, lacking names, they can't be resolved to the
definition.

[Also include a fix for llvm-dwarfdump/libDebugInfoDWARF to pretty print
types in type units]

llvm-svn: 360458
2019-05-10 19:15:29 +00:00
Eric Christopher c93f56d39e Temporarily Revert "[DebugInfo] Terminate more location-list ranges at the end of blocks"
as it was causing significant compile time regressions.

This reverts commit r359426 while we come up with testcases and additional ideas.

llvm-svn: 360301
2019-05-08 23:54:03 +00:00
Adrian Prantl e6e8db5e9b Debug Info: Support address space attributes on rvalue references.
DWARF5, 2.12 20ff says that

Any debugging information entry representing a pointer or reference
type [may have a DW_AT_address_class attribute].

The existing code (https://reviews.llvm.org/D29670) seems to take a
quite literal interpretation of that wording. I don't see a reason why
an rvalue reference isn't a reference type in the spirit of that
paragraph. This patch allows rvalue references to also have address
spaces.

rdar://problem/50511483

Differential Revision: https://reviews.llvm.org/D61625

llvm-svn: 360176
2019-05-07 17:42:38 +00:00
Fangrui Song da82ce99b7 [DebugInfo] Delete TypedDINodeRef
TypedDINodeRef<T> is a redundant wrapper of Metadata * that is actually a T *.

Accordingly, change DI{Node,Scope,Type}Ref uses to DI{Node,Scope,Type} * or their const variants.
This allows us to delete many resolve() calls that clutter the code.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D61369

llvm-svn: 360108
2019-05-07 02:06:37 +00:00
Amy Huang 987b969bab Fix bug in getCompleteTypeIndex in codeview debug info
Summary:
When there are multiple instances of a forward decl record type, only the first one is emitted with a type index, because
the type is added to a map with a null type index. Avoid this by reordering so that forward decl types aren't added to the map.

Reviewers: rnk

Subscribers: aprantl, hiraditya, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61460

llvm-svn: 360101
2019-05-06 23:37:03 +00:00
Eli Friedman 0b61d220c9 [AArch64][Windows] Compute function length correctly in unwind tables.
The primary fix here is to WinException.cpp: we need to exclude jump
tables when computing the length of a function, or else we fail to
correctly compute the length. (We can only compute the number of bytes
consumed by certain assembler directives after the entire file is
parsed. ".p2align" is one of those directives, and is used by jump table
generation.)

The secondary fix, to MCWin64EH, is to make sure we don't silently
miscompile if we hit a similar situation in the future.

It's possible we could extend ARM64EmitUnwindInfo so it allows function
bodies that contain assembler directives, but that's a lot more
complicated; see the FIXME in MCWin64EH.cpp.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41581 .

Differential Revision: https://reviews.llvm.org/D61095

llvm-svn: 359849
2019-05-03 00:10:45 +00:00
Fangrui Song 7bce25cd7d [AsmPrinter] Make AsmPrinter::HandlerInfo::Handler a unique_ptr
Handlers.clear() in AsmPrinter::doFinalization() will destroy these handlers.
A unique_ptr makes the ownership clearer.

llvm-svn: 359541
2019-04-30 09:14:02 +00:00
Markus Lavin a475da36eb [DebugInfo] DW_OP_deref_size in PrologEpilogInserter.
The PrologEpilogInserter need to insert a DW_OP_deref_size before
prepending a memory location expression to an already implicit
expression to avoid having the existing expression act on the memory
address instead of the value behind it.

The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
big-endian targets need to read the right size as simply truncating a
larger read would yield the wrong result (LSB bytes are not at the lower
address).

This re-commit fixes issues reported in the first one. Namely deref was
inserted under wrong conditions and additionally the deref_size argument
was incorrectly encoded.

Differential Revision: https://reviews.llvm.org/D59687

llvm-svn: 359535
2019-04-30 07:58:57 +00:00
Jeremy Morse 055aee1d8a [DebugInfo] Terminate more location-list ranges at the end of blocks
This patch fixes PR40795, where constant-valued variable locations can
"leak" into blocks placed at higher addresses. The root of this is that
DbgEntityHistoryCalculator terminates all register variable locations at
the end of each block, but not constant-value variable locations.

Fixing this requires constant-valued DBG_VALUE instructions to be
broadcast into all blocks where the variable location remains valid, as
documented in the LiveDebugValues section of SourceLevelDebugging.rst,
and correct termination in DbgEntityHistoryCalculator.

Differential Revision: https://reviews.llvm.org/D59431

llvm-svn: 359426
2019-04-29 09:13:16 +00:00
Nick Desaulniers 7ab164c4a4 [AsmPrinter] refactor to support %c w/ GlobalAddress'
Summary:
Targets like ARM, MSP430, PPC, and SystemZ have complex behavior when
printing the address of a MachineOperand::MO_GlobalAddress. Move that
handling into a new overriden method in each base class. A virtual
method was added to the base class for handling the generic case.

Refactors a few subclasses to support the target independent %a, %c, and
%n.

The patch also contains small cleanups for AVRAsmPrinter and
SystemZAsmPrinter.

It seems that NVPTXTargetLowering is possibly missing some logic to
transform GlobalAddressSDNodes for
TargetLowering::LowerAsmOperandForConstraint to handle with "i" extended
inline assembly asm constraints.

Fixes:
- https://bugs.llvm.org/show_bug.cgi?id=41402
- https://github.com/ClangBuiltLinux/linux/issues/449

Reviewers: echristo, void

Reviewed By: void

Subscribers: void, craig.topper, jholewinski, dschuff, jyknight, dylanmckay, sdardis, nemanjai, javed.absar, sbc100, jgravelle-google, eraman, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, jrtc27, atanasyan, jsji, llvm-commits, kees, tpimh, nathanchance, peter.smith, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60887

llvm-svn: 359337
2019-04-26 18:45:04 +00:00
Amy Huang 68c9199493 Recommitting r358783 and r358786 "[MS] Emit S_HEAPALLOCSITE debug info" with fixes for buildbot error (undefined assembler label).
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.

Reviewers: rnk

Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D61083

llvm-svn: 359149
2019-04-24 23:02:48 +00:00
David Blaikie 832c7d9f36 DebugInfo: Emit only declarations (not whole definitions) of non-unit user defined types into type units
While this doesn't come up in reasonable cases currently (the only user
defined types not in type units are ones without linkage - which makes
for near-ODR violations, because it'd be a type with linkage referencing
a type without linkage - such a type can't be validly defined in more
than one TU, so arguably it shouldn't be in a type unit to begin with -
but it's a convenient way to demonstrate an issue that will become more
revalent with homed modular debug info type definitions - which also
don't need to be in type units but more legitimately so).

Precursor to the Clang change to de-type-unit (by omitting the
'identifier') types homed due to strong linkage vtables. (making that
change without this one would lead to major type duplication in type
units)

llvm-svn: 359122
2019-04-24 18:09:44 +00:00
Francis Visoiu Mistrih 7fee2b89fd [Remarks] Add string deduplication using a string table
* Add support for uniquing strings in the remark streamer and emitting the string table in the remarks section.

* Add parsing support for the string table in the RemarkParser.

From this remark:

```
--- !Missed
Pass:     inline
Name:     NoDefinition
DebugLoc: { File: 'test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c',
            Line: 7, Column: 3 }
Function: printArgsNoRet
Args:
  - Callee:   printf
  - String:   ' will not be inlined into '
  - Caller:   printArgsNoRet
    DebugLoc: { File: 'test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c',
                Line: 6, Column: 0 }
  - String:   ' because its definition is unavailable'
...
```

to:

```
--- !Missed
Pass: 0
Name: 1
DebugLoc: { File: 3, Line: 7, Column: 3 }
Function: 2
Args:
  - Callee:   4
  - String:   5
  - Caller:   2
    DebugLoc: { File: 3, Line: 6, Column: 0 }
  - String:   6
...
```

And the string table in the .remarks/__remarks section containing:

```
inline\0NoDefinition\0printArgsNoRet\0
test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c\0printf\0
will not be inlined into \0 because its definition is unavailable\0
```

This is mostly supposed to be used for testing purposes, but it gives us
a 2x reduction in the remark size, and is an incremental change for the
updates to the remarks file format.

Differential Revision: https://reviews.llvm.org/D60227

llvm-svn: 359050
2019-04-24 00:06:24 +00:00
Amy Huang fc79ab9857 Revert "[MS] Emit S_HEAPALLOCSITE debug info" because of ToTWin64(db)
buildbot failure.

This reverts commit d07d6d6177 and
c774f687b6.

llvm-svn: 359034
2019-04-23 21:12:58 +00:00
David Blaikie 2f51176223 Reapply: "DebugInfo: Emit only one kind of accelerated access/name table""
Originally committed in r358931
Reverted in r358997

Seems this change made Apple accelerator tables miss names (because
names started respecting the CU NameTableKind GNU & assuming that
shouldn't produce accelerated names too), which is never correct (apple
accelerator tables don't have separators or CU lists - if present, they
must describe all names in all CUs).

Original Description:
Currently to opt in to debug_names in DWARFv5, the IR must contain
'nameTableKind: Default' which also enables debug_pubnames.

Instead, only allow one of {debug_names, apple_names, debug_pubnames,
debug_gnu_pubnames}.

nameTableKind: Default gives debug_names in DWARFv5 and greater,
debug_pubnames in v4 and earlier - and apple_names when tuning for lldb
on MachO.
nameTableKind: GNU always gives gnu_pubnames

llvm-svn: 359026
2019-04-23 19:00:45 +00:00
David Blaikie a2470a4653 Revert "DebugInfo: Emit only one kind of accelerated access/name table"
Regresses some apple_names situations - still investigating.

This reverts commit r358931.

llvm-svn: 358997
2019-04-23 15:03:24 +00:00
Fangrui Song efd94c56ba Use llvm::stable_sort
While touching the code, simplify if feasible.

llvm-svn: 358996
2019-04-23 14:51:27 +00:00
David Blaikie 68602ab2f3 DebugInfo: Emit only one kind of accelerated access/name table
Currently to opt in to debug_names in DWARFv5, the IR must contain
'nameTableKind: Default' which also enables debug_pubnames.

Instead, only allow one of {debug_names, apple_names, debug_pubnames,
debug_gnu_pubnames}.

nameTableKind: Default gives debug_names in DWARFv5 and greater,
debug_pubnames in v4 and earlier - and apple_names when tuning for lldb
on MachO.
nameTableKind: GNU always gives gnu_pubnames

llvm-svn: 358931
2019-04-22 22:45:11 +00:00
Amy Huang c774f687b6 [MS] Emit S_HEAPALLOCSITE debug info
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.

Reviewers: hans, rnk

Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D60800

llvm-svn: 358783
2019-04-19 21:09:11 +00:00
Ali Tamur 783d84bb39 [llvm] Prevent duplicate files in debug line header in dwarf 5: another attempt
Another attempt to land the changes in debug line header to prevent duplicate
files in Dwarf 5. I rolled back my previous commit because of a mistake in
generating the object file in a test. Meanwhile, I addressed some offline
comments and changed the implementation; the largest difference is that
MCDwarfLineTableHeader does not keep DwarfVersion but gets it as a parameter. I
also merged the patch to fix two lld tests that will strt to fail into this
patch.

Original Commit:

https://reviews.llvm.org/D59515

Original Message:
Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.

The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)

With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf
5) However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.

llvm-svn: 358732
2019-04-19 02:26:56 +00:00
Ali Tamur 6263365b08 Fix a typo in comments. [NFC]
llvm-svn: 358639
2019-04-18 02:39:37 +00:00
Nick Desaulniers 9609ce2f33 [AsmPrinter] hoist %a output template to base class for ARM+Aarch64
Summary:
X86 is quite complicated; so I intend to leave it as is. ARM+Aarch64 do
basically the same thing (Aarch64 did not correctly handle immediates,
ARM has a test llvm/test/CodeGen/ARM/2009-04-06-AsmModifier.ll that uses
%a with an immediate) for a flag that should be target independent
anyways.

Reviewers: echristo, peter.smith

Reviewed By: echristo

Subscribers: javed.absar, eraman, kristof.beyls, hiraditya, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60841

llvm-svn: 358618
2019-04-17 22:21:10 +00:00
Nick Desaulniers a2077bab40 [AsmPrinter] defer %c to base class for ARM, PPC, and Hexagon. NFC
Summary:
None of these derived classes do anything that the base class cannot.
If we remove these case statements, then the base class can handle them
just fine.

Reviewers: peter.smith, echristo

Reviewed By: echristo

Subscribers: nemanjai, javed.absar, eraman, kristof.beyls, hiraditya, kbarton, jsji, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60803

llvm-svn: 358603
2019-04-17 18:22:48 +00:00
Hans Wennborg 4e6b857922 Revert r358268 "[DebugInfo] DW_OP_deref_size in PrologEpilogInserter."
It causes clang to crash while building Chromium. See https://crbug.com/952230
for reproducer.

> The PrologEpilogInserter need to insert a DW_OP_deref_size before
> prepending a memory location expression to an already implicit
> expression to avoid having the existing expression act on the memory
> address instead of the value behind it.
>
> The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
> big-endian targets need to read the right size as simply truncating a
> larger read would yield the wrong result (LSB bytes are not at the lower
> address).
>
> Differential Revision: https://reviews.llvm.org/D59687

llvm-svn: 358281
2019-04-12 12:54:52 +00:00
Markus Lavin 138c76129b [DebugInfo] DW_OP_deref_size in PrologEpilogInserter.
The PrologEpilogInserter need to insert a DW_OP_deref_size before
prepending a memory location expression to an already implicit
expression to avoid having the existing expression act on the memory
address instead of the value behind it.

The reason for using DW_OP_deref_size and not plain DW_OP_deref is that
big-endian targets need to read the right size as simply truncating a
larger read would yield the wrong result (LSB bytes are not at the lower
address).

Differential Revision: https://reviews.llvm.org/D59687

llvm-svn: 358268
2019-04-12 08:23:55 +00:00
Eric Christopher 6b06c6a5ef Add explicit dependencies on MCSection.h and MCDwarf.h to the .cpp
files rather than rely on transitive includes from MCStreamer.h.

llvm-svn: 358263
2019-04-12 07:40:01 +00:00
Shiva Chen 7cc03bd064 [RISCV] Put data smaller than eight bytes to small data section
Because of gp = sdata_start_address + 0x800, gp with signed twelve-bit offset
could covert most of the small data section. Linker relaxation could transfer
the multiple data accessing instructions to a gp base with signed twelve-bit
offset instruction.

Differential Revision: https://reviews.llvm.org/D57493

llvm-svn: 358150
2019-04-11 04:59:13 +00:00
Nick Desaulniers 5277b3ff25 [AsmPrinter] refactor to remove remove AsmVariant. NFC
Summary:
The InlineAsm::AsmDialect is only required for X86; no architecture
makes use of it and as such it gets passed around between arch-specific
and general code while being unused for all architectures but X86.

Since the AsmDialect is queried from a MachineInstr, which we also pass
around, remove the additional AsmDialect parameter and query for it deep
in the X86AsmPrinter only when needed/as late as possible.

This refactor should help later planned refactors to AsmPrinter, as this
difference in the X86AsmPrinter makes it harder to make AsmPrinter more
generic.

Reviewers: craig.topper

Subscribers: jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, llvm-commits, peter.smith, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60488

llvm-svn: 358101
2019-04-10 16:38:43 +00:00
David Stenberg b96943b6a0 [DebugInfo] Track multiple registers in DbgEntityHistoryCalculator
Summary:
When calculating the debug value history, DbgEntityHistoryCalculator
would only keep track of register clobbering for the latest debug value
per inlined entity. This meant that preceding register-described debug
value fragments would live on until the next overlapping debug value,
ignoring any potential clobbering. This patch amends
DbgEntityHistoryCalculator so that it keeps track of all registers that
a inlined entity's currently live debug values are described by.

The DebugInfo/COFF/pieces.ll test case has had to be changed since
previously a register-described fragment would incorrectly outlive its
basic block.

The parent patch D59941 is expected to increase the coverage slightly,
as it makes sure that location list entries are inserted after clobbered
fragments, and this patch is expected to decrease it, as it stops
preceding register-described from living longer than they should. All in
all, this patch and the preceding patch has a negligible effect on the
output from `llvm-dwarfdump -statistics' for a clang-3.4 binary built
using the RelWithDebInfo build profile. "Scope bytes covered" increases
by 0.5%, and "variables with location" increases from 2212083 to
2212088, but it should improve the accuracy quite a bit.

This fixes PR40283.

Reviewers: aprantl, probinson, dblaikie, rnk, bjope

Reviewed By: aprantl

Subscribers: llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D59942

llvm-svn: 358073
2019-04-10 11:28:28 +00:00
David Stenberg 5ffec6deef [DebugInfo] Improve handling of clobbered fragments
Summary:
Currently the DbgValueHistorymap only keeps track of clobbered registers
for the last debug value that it has encountered. This could lead to
preceding register-described debug values living on longer in the
location lists than they should. See PR40283 for an example.  This
patch does not introduce tracking of multiple registers, but changes
the DbgValueHistoryMap structure to allow for that in a follow-up
patch. This patch is not NFC, as it at least fixes two bugs in
DwarfDebug (both are covered in the new clobbered-fragments.mir test):

* If a debug value was clobbered (its End pointer set), the value would
  still be added to OpenRanges, meaning that the succeeding location list
  entries could potentially contain stale values.

* If a debug value was clobbered, and there were non-overlapping
  fragments that were still live after the clobbering, DwarfDebug would
  not create a location list entry starting directly after the
  clobbering instruction. This meant that the location list could have
  a gap until the next debug value for the variable was encountered.

Before this patch, the history map was represented by <Begin, End>
pairs, where a new pair was created for each new debug value. When
dealing with partially overlapping register-described debug values, such
as in the following example:

  DBG_VALUE $reg2, $noreg, !1, !DIExpression(DW_OP_LLVM_fragment, 32, 32)
  [...]
  DBG_VALUE $reg3, $noreg, !1, !DIExpression(DW_OP_LLVM_fragment, 64, 32)
  [...]
  $reg2 = insn1
  [...]
  $reg3 = insn2

the history map would then contain the entries `[<DV1, insn1>, [<DV2, insn2>]`.
This would leave it up to the users of the map to be aware of
the relative order of the instructions, which e.g. could make
DwarfDebug::buildLocationList() needlessly complex. Instead, this patch
makes the history map structure monotonically increasing by dropping the
End pointer, and replacing that with explicit clobbering entries in the
vector. Each debug value has an "end index", which if set, points to the
entry in the vector that ends the debug value. The ending entry can
either be an overlapping debug value, or an instruction which clobbers
the register that the debug value is described by. The ending entry's
instruction can thus either be excluded or included in the debug value's
range. If the end index is not set, the debug value that the entry
introduces is valid until the end of the function.

Changes to test cases:

 * DebugInfo/X86/pieces-3.ll: The range of the first DBG_VALUE, which
   describes that the fragment (0, 64) is located in RDI, was
   incorrectly ended by the clobbering of RAX, which the second
   (non-overlapping) DBG_VALUE was described by. With this patch we
   get a second entry that only describes RDI after that clobbering.

 * DebugInfo/ARM/partial-subreg.ll: This test seems to indiciate a bug
   in LiveDebugValues that is caused by it not being aware of fragments.
   I have added some comments in the test case about that. Also, before
   this patch DwarfDebug would incorrectly include a register-described
   debug value from a preceding block in a location list entry.

Reviewers: aprantl, probinson, dblaikie, rnk, bjope

Reviewed By: aprantl

Subscribers: javed.absar, kristof.beyls, jdoerfert, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D59941

llvm-svn: 358072
2019-04-10 11:28:20 +00:00
Fangrui Song 56f70c625a [AsmPrinter] Delete unused RangeSpanList::addRange
llvm-svn: 358068
2019-04-10 10:35:10 +00:00
David Stenberg 6feef56d1b [DebugInfo] Rename DbgValueHistoryMap::{InstrRange -> Entry}, NFC
Summary:
In an upcoming commit the history map will be changed so that it
contains explicit entries for instructions that clobber preceding debug
values, rather than Begin- End range pairs, so generalize the name to
"Entry".

Also, prefix the iterator variable names in buildLocationList() with
"E". In an upcoming commit the entry will have query functions such as
"isD(e)b(u)gValue", which could at a glance make one confuse it for
iterations over MachineInstrs, so make the iterator names a bit more
distinct to avoid that.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59939

llvm-svn: 358060
2019-04-10 09:07:43 +00:00
David Stenberg 3739979c20 [DebugInfo] Make InstrRange into a class, NFC
Summary:
Replace use of std::pair by creating a class for the debug value
instruction ranges instead. This is a preparatory refactoring for
improving handling of clobbered fragments.

In an upcoming commit the Begin pointer will become a PointerIntPair, so
it will be cleaner to have a getter for that.

Reviewers: aprantl

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59938

llvm-svn: 358059
2019-04-10 09:07:32 +00:00
David Stenberg 2028ae975c [DebugInfo] Pass all values in DebugLocEntry's constructor, NFC
Summary:
With MergeValues() removed, amend DebugLocEntry's constructor so that it
takes multiple values rather than a single, and keep non-fragment values
in OpenRanges, as this allows some cleanup of the code in
buildLocationList().

Reviewers: aprantl, dblaikie, loladiro

Reviewed By: aprantl

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D59303

llvm-svn: 357988
2019-04-09 10:08:26 +00:00
David Stenberg 93b497a61d [DebugInfo] Remove redundant DebugLocEntry::MergeValues() function, NFC
Summary:
The MergeValues() function would try to merge two entries if they shared
the same beginning label. Having the same beginning label means that the
former entry's range would be empty; however, after D55919 we no longer
create entries for empty ranges, so we can no longer land in a situation
where that check in MergeValues would succeed. Instead, the "merging" is
done by keeping the live values from the preceding empty ranges in
OpenRanges, and adding them to the first non-empty range.

Reviewers: aprantl, dblaikie, loladiro

Reviewed By: aprantl

Subscribers: llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D59301

llvm-svn: 357974
2019-04-09 07:46:09 +00:00
Adrian Prantl 6ed5706a2b Add LLVM IR debug info support for Fortran COMMON blocks
COMMON blocks are a feature of Fortran that has no direct analog in C languages, but they are similar to data sections in assembly language programming. A COMMON block is a named area of memory that holds a collection of variables. Fortran subprograms may map the COMMON block memory area to their own, possibly distinct, non-empty list of variables. A Fortran COMMON block might look like the following example.

    COMMON /ALPHA/ I, J

    For this construct, the compiler generates a new scope-like DI construct (!DICommonBlock) into which variables (see I, J above) can be placed. As the common block implies a range of storage with global lifetime, the !DICommonBlock refers to a !DIGlobalVariable. The Fortran variable that comprise the COMMON block are also linked via metadata to offsets within the global variable that stands for the entire common block.

    @alpha_ = common global %alphabytes_ zeroinitializer, align 64, !dbg !27, !dbg !30, !dbg !33
    !14 = distinct !DISubprogram(…)
    !20 = distinct !DICommonBlock(scope: !14, declaration: !25, name: "alpha")
    !25 = distinct !DIGlobalVariable(scope: !20, name: "common alpha", type: !24)
    !27 = !DIGlobalVariableExpression(var: !25, expr: !DIExpression())
    !29 = distinct !DIGlobalVariable(scope: !20, name: "i", file: !3, type: !28)
    !30 = !DIGlobalVariableExpression(var: !29, expr: !DIExpression())
    !31 = distinct !DIGlobalVariable(scope: !20, name: "j", file: !3, type: !28)
    !32 = !DIExpression(DW_OP_plus_uconst, 4)
    !33 = !DIGlobalVariableExpression(var: !31, expr: !32)

    The DWARF generated for this is as follows.

    DW_TAG_common_block:
    DW_AT_name: alpha
    DW_AT_location: @alpha_+0
    DW_TAG_variable:
    DW_AT_name: common alpha
    DW_AT_type: array of 8 bytes
    DW_AT_location: @alpha_+0
    DW_TAG_variable:
    DW_AT_name: i
    DW_AT_type: integer*4
    DW_AT_location: @Alpha+0
    DW_TAG_variable:
    DW_AT_name: j
    DW_AT_type: integer*4
    DW_AT_location: @Alpha+4

Patch by Eric Schweitz!

Differential Revision: https://reviews.llvm.org/D54327

llvm-svn: 357934
2019-04-08 19:13:55 +00:00
Fangrui Song 2c5c12c041 Change some dyn_cast to more apropriate isa. NFC
llvm-svn: 357773
2019-04-05 16:16:23 +00:00
Eric Christopher 798e83b5d6 NFC: Move API uses of MD5::MD5Result to Optional rather than a pointer.
Differential Revision: https://reviews.llvm.org/D60290

llvm-svn: 357736
2019-04-04 23:34:38 +00:00
Evandro Menezes 85bd3978ae [IR] Refactor attribute methods in Function class (NFC)
Rename the functions that query the optimization kind attributes.

Differential revision: https://reviews.llvm.org/D60287

llvm-svn: 357731
2019-04-04 22:40:06 +00:00
Evandro Menezes 7c711ccf36 [IR] Create new method in `Function` class (NFC)
Create method `optForNone()` testing for the function level equivalent of
`-O0` and refactor appropriately.

Differential revision: https://reviews.llvm.org/D59852

llvm-svn: 357638
2019-04-03 21:27:03 +00:00
Alex Bradbury da20f5ca74 [RISCV] Generate address sequences suitable for mcmodel=medium
This patch adds an implementation of a PC-relative addressing sequence to be
used when -mcmodel=medium is specified. With absolute addressing, a 'medium'
codemodel may cause addresses to be out of range. This is because while
'medium' implies a 2 GiB addressing range, this 2 GiB can be at any offset as
opposed to 'small', which implies the first 2 GiB only.

Note that LLVM/Clang currently specifies code models differently to GCC, where
small and medium imply the same functionality as GCC's medlow and medany
respectively.

Differential Revision: https://reviews.llvm.org/D54143
Patch by Lewis Revill.

llvm-svn: 357393
2019-04-01 14:42:56 +00:00
Francis Visoiu Mistrih ee1a6e70fa [Remarks] Emit a section containing remark diagnostics metadata
A section containing metadata on remark diagnostics will be emitted if
the flag (-mllvm) -remarks-section is present.

For now, the metadata is:

* a magic number for remarks: "REMARKS\0"
* the version number: a little-endian uint64_t
* the absolute file path to the serialized remark diagnostics: a
  null-terminated string.

Differential Revision: https://reviews.llvm.org/D59571

llvm-svn: 357043
2019-03-27 01:13:59 +00:00
Ali Tamur 02e96648d7 Revert "[llvm] Reapply "Prevent duplicate files in debug line header in dwarf 5.""
This reverts commit rL357020.

The commit broke the test llvm/test/tools/llvm-objdump/embedded-source.test
on some builds including clang-ppc64be-linux-multistage,
clang-s390x-linux, clang-with-lto-ubuntu, clang-x64-windows-msvc,
llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast (and others).

llvm-svn: 357026
2019-03-26 20:05:27 +00:00
Ali Tamur 2f5cd03a3f [llvm] Reapply "Prevent duplicate files in debug line header in dwarf 5."
Reapply rL356941 after regenerating the object file in the failing test
llvm/test/tools/llvm-objdump/embedded-source.test from source.

Original commit message:

[llvm] Prevent duplicate files in debug line header in dwarf 5.

Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.

The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)

With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf 5)
However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D59515

llvm-svn: 357018
2019-03-26 18:53:23 +00:00
Ali Tamur fdce82a814 Revert "[llvm] Prevent duplicate files in debug line header in dwarf 5."
This reverts commit 312ab05887.

My commit broke the build; I will revert and find out what happened.

llvm-svn: 356951
2019-03-25 21:09:07 +00:00
Ali Tamur 312ab05887 [llvm] Prevent duplicate files in debug line header in dwarf 5.
Summary:

Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.

The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)

With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf 5)
However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.

Reviewers: dblaikie, probinson, aprantl, espindola

Reviewed By: probinson

Subscribers: emaste, jvesely, nhaehnle, aprantl, javed.absar, arichardson, hiraditya, MaskRay, rupprecht, jdoerfert, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D59515

llvm-svn: 356941
2019-03-25 20:08:00 +00:00
Florian Hahn 1663c9466f [DwarfDebug] Skip entries to big for 16 bit size field in Dwarf < 5.
Nothing prevents entries from being bigger than the 16 bit size field in
Dwarf < 5. For entries that are too big, just emit an empty entry
instead of crashing.

This fixes PR41038.

Reviewers: probinson, aprantl, davide

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D59518

llvm-svn: 356514
2019-03-19 20:37:06 +00:00