Commit Graph

516 Commits

Author SHA1 Message Date
Adrian Prantl a8e56458e6 Let replaceVTableHolder accept any type.
In Rust, a trait can be implemented for any type, and if a trait
object pointer is used for the type, then a virtual table will be
emitted for that trait/type combination.

We would like debuggers to be able to inspect trait objects, which
requires finding the concrete type associated with a given vtable.

This patch changes LLVM so that any type can be passed to
replaceVTableHolder. This allows the Rust compiler to emit the needed
debug info -- associating a vtable with the concrete type for which it
was emitted.

This is a DWARF extension: DWARF only specifies the meaning of
DW_AT_containing_type in one specific situation. This style of DWARF
extension is routine, though, and LLVM already has one such case for
DW_AT_containing_type.

Patch by Tom Tromey!

Differential Revision: https://reviews.llvm.org/D39503

llvm-svn: 317730
2017-11-08 22:04:43 +00:00
Adrian Prantl 2049c0d734 Remove unreachable code. (NFC)
MachineLocation::getOffset() always returns 0.

rdar://problem/33580047

llvm-svn: 309823
2017-08-02 15:22:17 +00:00
Wolfgang Pieb e60147c89f [DWARF] Move a couple of member functions to the DWARFUnit baseclass. NFC.
Reviewer: dblaikie

Differential revision: https://reviews.llvm.org/D34765

llvm-svn: 306771
2017-06-30 00:27:45 +00:00
Florian Hahn ffc498dfcc Align definition of DW_OP_plus with DWARF spec [3/3]
Summary:
This patch is part of 3 patches that together form a single patch, but must be introduced in stages in order not to break things.
 
The way that LLVM interprets DW_OP_plus in DIExpression nodes is basically that of the DW_OP_plus_uconst operator since LLVM expects an unsigned constant operand. This unnecessarily restricts the DW_OP_plus operator, preventing it from being used to describe the evaluation of runtime values on the expression stack. These patches try to align the semantics of DW_OP_plus and DW_OP_minus with that of the DWARF definition, which pops two elements off the expression stack, performs the operation and pushes the result back on the stack.
 
This is done in three stages:
• The first patch (LLVM) adds support for DW_OP_plus_uconst.
• The second patch (Clang) contains changes all its uses from DW_OP_plus to DW_OP_plus_uconst.
• The third patch (LLVM) changes the semantics of DW_OP_plus and DW_OP_minus to be in line with its DWARF meaning. This patch includes the bitcode upgrade from legacy DIExpressions.

Patch by Sander de Smalen.

Reviewers: echristo, pcc, aprantl

Reviewed By: aprantl

Subscribers: fhahn, javed.absar, aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D33894

llvm-svn: 305386
2017-06-14 13:14:38 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Peter Collingbourne 6f0ecca3b5 IR: Give function GlobalValue::getRealLinkageName() a less misleading name: dropLLVMManglingEscape().
This function gives the wrong answer on some non-ELF platforms in some
cases. The function that does the right thing lives in Mangler.h. To try to
discourage people from using this function, give it a different name.

Differential Revision: https://reviews.llvm.org/D33162

llvm-svn: 303134
2017-05-16 00:39:01 +00:00
David Blaikie 488393f822 DWARF: Avoid cross-CU references under Fission
Turns out that the Fission/Split DWARF package format (DWP) is currently
insufficient to handle cross-CU (ref_addr) references. So for now,
duplicate any debug info needed in these situations:
* inlined_subroutine's abstract_origin
* inlined variable's abstract_origin
* types

Keep the ref_addr behavior in general, including in the split DWARF
inline debug info that can be emitted into the object files for online
symbolication.
Keep a flag to use the old (ref_addr) behavior for testing ways of
addressing this limitation in the DWP tool (& for those not using DWP
packaging).

llvm-svn: 302858
2017-05-12 01:13:45 +00:00
Adrian Prantl fed4f399d3 Remove line and file from DINamespace.
Fixes the issue highlighted in
http://lists.llvm.org/pipermail/cfe-dev/2014-June/037500.html.

The DW_AT_decl_file and DW_AT_decl_line attributes on namespaces can
prevent LLVM from uniquing types that are in the same namespace. They
also don't carry any meaningful information.

rdar://problem/17484998
Differential Revision: https://reviews.llvm.org/D32648

llvm-svn: 301706
2017-04-28 22:25:46 +00:00
Adrian Prantl 1d12b885b0 Add support for DW_TAG_thrown_type.
For Swift we would like to be able to encode the error types that a
function may throw, so the debugger can display them alongside the
function's return value when finish-ing a function.

DWARF defines DW_TAG_thrown_type (intended to be used for C++ throw()
declarations) that is a perfect fit for this purpose. This patch wires
up support for DW_TAG_thrown_type in LLVM by adding a list of thrown
types to DISubprogram.

To offset the cost of the extra pointer, there is a follow-up patch
that turns DISubprogram into a variable-length node.

rdar://problem/29481673

Differential Revision: https://reviews.llvm.org/D32559

llvm-svn: 301489
2017-04-26 22:56:44 +00:00
David Blaikie 85366acf15 Avoid using relocations for ref_addr in .dwo files
In dwo files the fixed offset can be used - if the dwos are linked into
a dwp, the dwo consumer must use the dwp tables to find out where the
original range of the debug_info was and resolve the "section relative"
value relative to that original range - effectively
avoiding/reimplementing the relocation handling.

llvm-svn: 301072
2017-04-22 07:53:44 +00:00
Adrian Prantl c12cee3600 Fix bug that caused DwarfExpression to drop DW_OP_deref from FI locations
- introduced in r300522 and found via the Swift LLDB testsuite.

The fix is to set the location kind to memory whenever an FrameIndex
location is emitted.

rdar://problem/31707602

llvm-svn: 300793
2017-04-19 23:42:25 +00:00
Adrian Prantl 295c952b67 Revert "Fix bug that caused DwarfExpression to drop DW_OP_deref from FI locations"
This reverts commit r300790.

llvm-svn: 300792
2017-04-19 23:42:17 +00:00
Adrian Prantl 78ff122709 Fix bug that caused DwarfExpression to drop DW_OP_deref from FI locations
- introduced in r300522 and found via the Swift LLDB testsuite.

The fix is to set the location kind to memory whenever an FrameIndex
location is emitted.

rdar://problem/31707602

llvm-svn: 300790
2017-04-19 23:34:14 +00:00
Adrian Prantl 6825fb64e9 PR32382: Fix emitting complex DWARF expressions.
The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
  - describe a variable in a register
  - consist of only a DW_OP_reg
2. Memory location descriptions
  - describe the address of a variable
3. Implicit location descriptions
  - describe the value of a variable
  - end with DW_OP_stack_value & friends

The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident.  This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.

This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.

There are two major changes in this patch:

I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.

When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
  DBG_VALUE, [RBP-8]                        --> DW_OP_fbreg -8
  DBG_VALUE, RAX                            --> DW_OP_reg0 +0
  DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0

All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.

https://bugs.llvm.org/show_bug.cgi?id=32382
<rdar://problem/31205000>

Differential Revision: https://reviews.llvm.org/D31439

llvm-svn: 300522
2017-04-18 01:21:53 +00:00
Konstantin Zhuravlyov dc77b2e960 Distinguish between code pointer size and DataLayout::getPointerSize() in DWARF info generation
llvm-svn: 300463
2017-04-17 17:41:25 +00:00
Adrian Prantl 956484b7b5 Replace uses of DwarfExpression::addMachineReg* with addMachineRegExpression
and mark the methods as protected.

Besides reducing the surface area of DwarfExpression, this is in
preparation for an upcoming bugfix in the DwarfExpression
implementation, for which it will be necessary to defer emitting
register operations until the rest of the expression is known.

NFC

llvm-svn: 298309
2017-03-20 21:35:09 +00:00
Adrian Prantl a63b8e8227 Rename methods in DwarfExpression to adhere to the LLVM coding guidelines.
NFC.

llvm-svn: 297966
2017-03-16 17:42:45 +00:00
Adrian Prantl 19aadf57c8 Revert "Debug Info: Add basic support for external types references."
This reverts commit r242302. External type refs of this form were
never used by any LLVM frontend so this is effectively dead code.
(They were introduced to support clang module debug info, but in the
end we came up with a better design that doesn't use this feature at
all.)

rdar://problem/25897929

Differential Revision: https://reviews.llvm.org/D30917

llvm-svn: 297684
2017-03-13 22:56:14 +00:00
Konstantin Zhuravlyov d5561e0a0b [DebugInfo] Emit address space with DW_AT_address_class attribute for pointer and reference types
Differential Revision: https://reviews.llvm.org/D29670

llvm-svn: 297320
2017-03-08 23:55:44 +00:00
Paul Robinson d4f1c487f3 Alphabetize some cases (NFC)
llvm-svn: 296655
2017-03-01 19:01:47 +00:00
Paul Robinson 91d74813a6 [DWARF] Default lower bound should respect requested DWARF version.
DWARF may define a default lower-bound for arrays in languages defined
in a particular DWARF version.  But the logic to suppress an
unnecessary lower-bound attribute was looking at the hard-coded
default DWARF version, not the version that had been requested.

Also updated the list with all languages defined in DWARF v5.

Differential Revision: http://reviews.llvm.org/D30484

llvm-svn: 296652
2017-03-01 18:32:37 +00:00
Paul Robinson cddd60445e [DWARFv5] Emit new unit header format.
Requesting DWARF v5 will now get you the new compile-unit and
type-unit headers.  llvm-dwarfdump will also recognize them.

Differential Revision: http://reviews.llvm.org/D30206

llvm-svn: 296514
2017-02-28 20:24:55 +00:00
David Blaikie a0e3c75187 DebugInfo: ensure type and namespace names are included in pubnames/pubtypes even when they are only present in type units
While looking to add support for placing singular types (types that will
only be emitted in one place (such as attached to a strong vtable or
explicit template instantiation definition)) not in type units (since
type units have overhead) I stumbled across that change causing an
increase in pubtypes.

Turns out we were missing some types from type units if they were only
referenced from other type units and not from the debug_info section.

This fixes that, following GCC's line of describing the offset of such
entities as the CU die (since there's no compile unit-relative offset
that would describe such an entity - they aren't in the CU). Also like
GCC, this change prefers to describe the type stub within the CU rather
than the "just use the CU offset" fallback where possible. This may give
the DWARF consumer some opportunity to find the extra info in the type
stub - though I'm not sure GDB does anything with this currently.

The size of the pubnames/pubtypes sections now match exactly with or
without type units enabled.

This nearly triples (+189%) the pubtypes section for a clang self-host
and grows pubnames by 0.07% (without compression). For a total of 8%
increase in debug info sections of the objects of a Split DWARF build
when using type units.

llvm-svn: 293971
2017-02-03 00:44:18 +00:00
Dehao Chen 0944a8c2ec Change debug-info-for-profiling from a TargetOption to a function attribute.
Summary: LTO requires the debug-info-for-profiling to be a function attribute.

Reviewers: echristo, mehdi_amini, dblaikie, probinson, aprantl

Reviewed By: mehdi_amini, dblaikie, aprantl

Subscribers: aprantl, probinson, ahatanak, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D29203

llvm-svn: 293833
2017-02-01 22:45:09 +00:00
Dehao Chen 1ce8d6ca59 Add -debug-info-for-profiling to emit more debug info for sample pgo profile collection
Summary:
SamplePGO binaries built with -gmlt to collect profile. The current -gmlt debug info is limited, and we need some additional info:

* start line of all subprograms
* linkage name of all subprograms
* standalone subprograms (functions that has neither inlined nor been inlined)

This patch adds these information to the -gmlt binary. The impact on speccpu2006 binary size (size increase comparing with -g0 binary, also includes data for -g binary, which does not change with this patch):

               -gmlt(orig) -gmlt(patched) -g
433.milc       4.68%       5.40%          19.73%
444.namd       8.45%       8.93%          45.99%
447.dealII     97.43%      115.21%        374.89%
450.soplex     27.75%      31.88%         126.04%
453.povray     21.81%      26.16%         92.03%
470.lbm        0.60%       0.67%          1.96%
482.sphinx3    5.77%       6.47%          26.17%
400.perlbench  17.81%      19.43%         73.08%
401.bzip2      3.73%       3.92%          12.18%
403.gcc        31.75%      34.48%         122.75%
429.mcf        0.78%       0.88%          3.89%
445.gobmk      6.08%       7.92%          42.27%
456.hmmer      10.36%      11.25%         35.23%
458.sjeng      5.08%       5.42%          14.36%
462.libquantum 1.71%       1.96%          6.36%
464.h264ref    15.61%      16.56%         43.92%
471.omnetpp    11.93%      15.84%         60.09%
473.astar      3.11%       3.69%          14.18%
483.xalancbmk  56.29%      81.63%         353.22%
geomean        15.60%      18.30%         57.81%

Debug info size change for -gmlt binary with this patch:

433.milc       13.46%
444.namd       5.35%
447.dealII     18.21%
450.soplex     14.68%
453.povray     19.65%
470.lbm        6.03%
482.sphinx3    11.21%
400.perlbench  8.91%
401.bzip2      4.41%
403.gcc        8.56%
429.mcf        8.24%
445.gobmk      29.47%
456.hmmer      8.19%
458.sjeng      6.05%
462.libquantum 11.23%
464.h264ref    5.93%
471.omnetpp    31.89%
473.astar      16.20%
483.xalancbmk  44.62%
geomean        16.83%

Reviewers: davidxl, echristo, dblaikie

Reviewed By: echristo, dblaikie

Subscribers: aprantl, probinson, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D25434

llvm-svn: 292457
2017-01-19 00:44:11 +00:00
Victor Leschuk cbddae74f5 DebugInfo: support for DW_FORM_implicit_const
Support for DW_FORM_implicit_const DWARFv5 feature.
When this form is used attribute value goes to .debug_abbrev section (as SLEB).
As this form would break any debug tool which doesn't support DWARFv5
it is guarded by dwarf version check. Attempt to use this form with
dwarf version <= 4 is considered a fatal error.

Differential Revision: https://reviews.llvm.org/D28456

llvm-svn: 291599
2017-01-10 21:18:26 +00:00
Adrian Prantl 8fafb8d378 Fix LLVM's use of DW_OP_bit_piece in DWARF expressions.
LLVM's use of DW_OP_bit_piece is incorrect and a based on a
misunderstanding of the wording in the DWARF specification. The offset
argument of DW_OP_bit_piece refers to the offset into the location
that is on the top of the DWARF expression stack, and not an offset
into the source variable. This has since also been clarified in the
DWARF specification.

This patch fixes all uses of DW_OP_bit_piece to emit the correct
offset and simplifies the DwarfExpression class to semi-automaticaly
emit empty DW_OP_pieces to adjust the offset of the source variable,
thus simplifying the code using DwarfExpression.

While this is an incompatible bugfix, in practice I don't expect this
to be much of a problem since LLVM's old interpretation and the
correct interpretation of DW_OP_bit_piece differ only when there are
gaps in the fragmented locations of the described variables or if
individual fragments are smaller than a byte. LLDB at least won't
interpret locations with gaps in them because is has no way to present
undefined bits in a variable, and there is a high probability that an
old-form expression will be malformed when interpreted correctly,
because the DW_OP_bit_piece offset will be outside of the location at
the top of the stack.

As a nice side-effect, this patch enables us to use a more efficient
encoding for subregisters: In order to express a sub-register at a
non-zero offset we now use a DW_OP_bit_piece instead of shifting the
value into place manually.

This patch also adds missing test coverage for code paths that weren't
exercised before.

<rdar://problem/29335809>
Differential Revision: https://reviews.llvm.org/D27550

llvm-svn: 289266
2016-12-09 20:43:40 +00:00
Adrian Prantl 941fa7588b [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

llvm-svn: 288683
2016-12-05 18:04:47 +00:00
Paul Robinson dad4907bc1 [DWARF] Put linkage-name on abstract origin even when there's a declaration.
In r266692, we made it possible to emit linkage names for just inlined
functions, putting the attribute on the abstract origin. Make sure we
don't think the linkage-name was already emitted on a declaration.

Differential Revision: http://reviews.llvm.org/D27320

llvm-svn: 288450
2016-12-02 01:55:17 +00:00
Greg Clayton 35630c3357 This change removes the dependency on DwarfDebug that was used for DW_FORM_ref_addr by making a new DIEUnit class in DIE.cpp.
The DIEUnit class represents a compile or type unit and it owns the unit DIE as an instance variable. This allows anyone with a DIE, to get the unit DIE, and then get back to its DIEUnit without adding any new ivars to the DIE class. Why was this needed? The DIE class has an Offset that is always the CU relative DIE offset, not the "offset in debug info section" as was commented in the header file (the comment has been corrected). This is great for performance because most DIE references are compile unit relative and this means most code that accessed the DIE's offset didn't need to make it into a compile unit relative offset because it already was. When we needed to emit a DW_FORM_ref_addr though, we needed to find the absolute offset of the DIE by finding the DIE's compile/type unit. This class did have the absolute debug info/type offset and could be added to the CU relative offset to compute the absolute offset. With this change we can easily get back to a DIE's DIEUnit which will have this needed offset. Prior to this is required having a DwarfDebug and required calling:

DwarfCompileUnit *DwarfDebug::lookupUnit(const DIE *CU) const;
Now we can use the DIEUnit class to do so without needing DwarfDebug. All clients now use DIEUnit objects (the DwarfDebug stack and the DwarfLinker). A follow on patch for the DWARF generator will also take advantage of this.

Differential Revision: https://reviews.llvm.org/D27170

llvm-svn: 288399
2016-12-01 18:56:29 +00:00
David Blaikie ce3c8ef26e [DebugInfo] Add support for DW_AT_main_subprogram on subprograms
Patch by Tom Tromey! (for use with Rust)

llvm-svn: 288068
2016-11-28 21:32:19 +00:00
Greg Clayton e65439797a Rely on a single DWARF version instead of having two copies
This patch makes AsmPrinter less reliant on DwarfDebug by relying on the DWARF version in the AsmPrinter's MCStreamer's MCContext. This allows us to remove the redundant DWARF version from DwarfDebug. It also lets us change code that used to access the AsmPrinter's DwarfDebug just to get to the DWARF version by changing the DWARF version accessor on AsmPrinter so that it grabs the version from its MCStreamer's MCContext.

Differential Revision: https://reviews.llvm.org/D27032

llvm-svn: 287839
2016-11-23 23:30:37 +00:00
Adrian Prantl dbfda63695 Add DWARF debug info support for C++11 inline namespaces.
This implements the DWARF 5 DW_AT_export_symbols feature:
http://dwarfstd.org/ShowIssue.php?issue=141212.1

<rdar://problem/18616046>

llvm-svn: 285959
2016-11-03 19:42:02 +00:00
Victor Leschuk e1156c2eb0 DebugInfo: make DW_TAG_atomic_type valid
DW_TAG_atomic_type was already included in Dwarf.defs and emitted correctly,
however Verifier didn't recognize it as valid.
Thus we introduce the following changes:

  * Make DW_TAG_atomic_type valid tag for IR and DWARF (enabled only with -gdwarf-5)
  * Add it to related docs
  * Add DebugInfo tests

Differential Revision: https://reviews.llvm.org/D26144

llvm-svn: 285624
2016-10-31 19:09:38 +00:00
Victor Leschuk a37660c669 DebugInfo: fix incorrect alignment type (NFC)
Change type of some missed DebugInfo-related alignment variables,
that are still uint64_t, to uint32_t.

Original change introduced in r284482.

llvm-svn: 285242
2016-10-26 21:32:29 +00:00
Victor Leschuk 3c9899842b DebugInfo: support for DWARFv5 DW_AT_alignment attribute
* Assume that clang passes non-zero alignment value to DIBuilder
only in case when it was forced by C++11 'alignas', C11 '_Alignas'
or compiler attribute '__attribute__((aligned (N)))'.

* Emit DW_AT_alignment if alignment is specified for type/object.

Differential Revision: https://reviews.llvm.org/D24425

llvm-svn: 285189
2016-10-26 11:59:03 +00:00
Vassil Vassilev df5042ab61 Revert r285181 "DebugInfo: support for DWARFv5 DW_AT_alignment attribute".
The commit broke the builds.

llvm-svn: 285183
2016-10-26 10:13:47 +00:00
Victor Leschuk e398c6afa9 DebugInfo: support for DWARFv5 DW_AT_alignment attribute
* Assume that clang passes non-zero alignment value to DIBuilder
only in case when it was forced by C++11 'alignas', C11 '_Alignas'
or compiler attribute '__attribute__((aligned (N)))'.

* Emit DW_AT_alignment if alignment is specified for type/object.

Differential Revision: https://reviews.llvm.org/D24425

llvm-svn: 285181
2016-10-26 08:55:27 +00:00
Victor Leschuk 2ede126b1b DebugInfo: preparation to implement DW_AT_alignment
- Add alignment attribute to DIVariable family
 - Modify bitcode format to match new DIVariable representation
 - Update tests to match these changes (also add bitcode upgrade test)
 - Expect that frontend passes non-zero align value only when it is not default
   (was forcibly aligned by alignas()/_Alignas()/__atribute__(aligned())

Differential Revision: https://reviews.llvm.org/D25073

llvm-svn: 284678
2016-10-20 00:13:12 +00:00
Victor Leschuk 197aa3192d DebugInfo: change alignment type from uint64_t to uint32_t to save space.
In futher patches we shall have alignment field added to DIVariable family
and switching from uint64_t to uint32_t will save 4 bytes per variable.

Differential Revision: https://reviews.llvm.org/D25620

llvm-svn: 284482
2016-10-18 14:31:22 +00:00
Eugene Zelenko 1804a77b2a Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes.
Differential revision: https://reviews.llvm.org/D23861

llvm-svn: 279695
2016-08-25 00:45:04 +00:00
Adrian Prantl c19dee734f Support the DW_AT_noreturn DWARF flag.
This is used to mark functions with the C++11 [[ noreturn ]] or C11 _Noreturn
attributes.

Patch by Victor Leschuk!

https://reviews.llvm.org/D23167

llvm-svn: 278940
2016-08-17 16:02:43 +00:00
Amjad Aboud acee568545 [codeview] Improved array type support.
Added support for:
1. Multi dimension array.
2. Array of structure type, which previously was declared incompletely.
3. Dynamic size array.
4. Array where element type is a typedef, volatile or constant (this should resolve PR28311).

Differential Revision: http://reviews.llvm.org/D21526

llvm-svn: 275167
2016-07-12 12:06:34 +00:00
David Majnemer 28c3646f82 [COFF, Dwarf] Don't emit DW_AT_location for dllimported entities
There exists no relocation which can describe the address of a
dllimported variable: do not try to describe their location.

llvm-svn: 274986
2016-07-09 20:47:48 +00:00
Reid Kleckner de3d8b500f [DebugInfo] Add calling convention support for DWARF and CodeView
Summary:
Now DISubroutineType has a 'cc' field which should be a DW_CC_ enum.  If
it is present and non-zero, the backend will emit it as a
DW_AT_calling_convention attribute. On the CodeView side, we translate
it to the appropriate enum for the LF_PROCEDURE record.

I added a new LLVM vendor specific enum to the list of DWARF calling
conventions. DWARF does not appear to attempt to standardize these, so I
assume it's OK to do this until we coordinate with GCC on how to emit
vectorcall convention functions.

Reviewers: dexonsmith, majnemer, aaboud, amccarth

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D21114

llvm-svn: 272197
2016-06-08 20:34:29 +00:00
David Blaikie c53e18d93a DWARF: Omit DW_AT_APPLE attributes (except ObjC ones) when not targeting LLDB
These attributes aren't used by other debuggers (& may be confused with
other DWARF extensions) so they just waste space (about 1.5% on .dwo
file size on a random large program I tested).

We could remove the ObjC property ones too, but I figured they were
probably more necessary when trying to understand ObjC (I could be wrong
though) & so any debugger interested in working with ObjC would use
them, perhaps? (also, there are some legacy tests in Clang that test for
them - making it one of those annoying cross-project commits and/or
cleanup to refactor those tests)

llvm-svn: 270613
2016-05-24 21:19:28 +00:00
Peter Collingbourne 96c9ae6a20 CodeGen: Do not require a MachineFunction just to create a DIEDwarfExpression.
We are about to start using DIEDwarfExpression to create global variable
DIEs, which happens before we generate code for functions.

Differential Revision: http://reviews.llvm.org/D20412

llvm-svn: 270257
2016-05-20 19:35:17 +00:00
Adrian Prantl 6323ddf99c Debug Info: Introduce a DwarfDebug::UseDWARF2Bitfields flag
instead of having DwarfUnit query the debugger tuning options.

Follow-up commmit to r269827.
Thanks to Paul Robinson for pointing this out!

llvm-svn: 269840
2016-05-17 21:07:16 +00:00
Adrian Prantl f0a41089ff Debug Info: Don't emit bitfields in the DWARF4 format when tuning for GDB.
As discovered in PR27758, GDB does not fully support the DWARF 4 format.
This patch ensures we always emit bitfields in the DWARF 2 when tuning for GDB.

llvm-svn: 269827
2016-05-17 20:12:08 +00:00
Adrian Prantl 7aa34c8cbb Debug Info: Don't emit a DW_AT_data_member_location for DWARF bitfields.
The DWARF spec states that a member entry may have either a
DW_AT_data_member_location or a DW_AT_data_bit_offset, but not both.

This fixes a bug found in PR 27758.

llvm-svn: 269731
2016-05-17 02:37:53 +00:00
Adrian Prantl e7d833defb Debug info: Don't emit a DW_AT_byte_size when emitting a DWARF4 bit field.
The DWARF spec clearly states that a bit field member should have either a
DW_AT_byte_size or a DW_AT_bit_size, but not both.
Also the DW_AT_byte_size is redundant with the size of the type of the member.

This fixes a bug found in PR 27758.

llvm-svn: 269714
2016-05-16 22:45:10 +00:00
Amjad Aboud 72da9391f0 Reverting 268054 & 268063 as they caused PR27579.
llvm-svn: 268150
2016-04-30 01:44:07 +00:00
Amjad Aboud 293ee8bba1 Recommitted r264280 "Supporting all entities declared in lexical scope in LLVM debug info."
After fixing PR26942 in r267004.

llvm-svn: 268054
2016-04-29 16:07:55 +00:00
Adrian Prantl e5447574c8 Debug Info: Restore the pre-r240853 behavior for DWARF2 bitfields.
The DWARF2 specification of DW_AT_bit_offset is ambiguous for
little-endian machines, but by restoring to the old behavior
we match what debuggers expect and what other popular compilers
generate.

llvm-svn: 267896
2016-04-28 15:37:52 +00:00
Adrian Prantl f393d313ec Debug info: Support DWARF4 bitfields via DW_AT_data_bit_offset.
The DWARF2 specification of DW_AT_bit_offset was written from the perspective of
a big-endian machine with unclear semantics for other systems.  DWARF4
deprecated DW_AT_bit_offset and introduced a new attribute DW_AT_data_bit_offset
that simply counts the number of bits from the beginning of the containing
entity regardless of endianness.

After this patch LLVM emits DW_AT_bit_offset for DWARF 2 or 3 and
DW_AT_data_bit_offset when DWARF 4 or later is requested.

llvm-svn: 267895
2016-04-28 15:37:48 +00:00
Duncan P. N. Exon Smith a59d3e5af8 DebugInfo: Remove MDString-based type references
Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*.  It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.

Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType.  The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.

This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata.  Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.

The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":

  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html

llvm-svn: 267296
2016-04-23 21:08:00 +00:00
Paul Robinson 43d1e45347 [DWARF] Force a linkage_name on an inlined subprogram's abstract origin.
When we suppress linkage names, for a non-inlined subprogram the name
can still be found in the object-file symbol table, because we have
the code address of the subprogram.  This is not necessarily the case
for an inlined subprogram, so we still want to emit the linkage name
in the DWARF.  Put this on the abstract-origin DIE because it's common
to all inlined instances.

Differential Revision: http://reviews.llvm.org/D18706

llvm-svn: 266692
2016-04-18 22:41:41 +00:00
Reid Kleckner 01bc66a8ce Revert "Recommitted r263424 "Supporting all entities declared in lexical scope in LLVM debug info." After fixing PR26942 (the fix is included in this commit)."
This reverts commit r264280.

This broke building Chromium for iOS. We'll upload a reproducer to the
PR soon.

llvm-svn: 264334
2016-03-24 20:38:49 +00:00
Amjad Aboud 6ff7e10052 Recommitted r263424 "Supporting all entities declared in lexical scope in LLVM debug info."
After fixing PR26942 (the fix is included in this commit).

Differential Revision: http://reviews.llvm.org/D18350

llvm-svn: 264280
2016-03-24 13:30:16 +00:00
Peter Collingbourne a1f8625662 DebugInfo: Add ability to not emit DW_AT_vtable_elem_location for virtual functions.
A virtual index of -1u indicates that the subprogram's virtual index is
unrepresentable (for example, when using the relative vtable ABI), so do
not emit a DW_AT_vtable_elem_location attribute for it.

Differential Revision: http://reviews.llvm.org/D18236

llvm-svn: 263765
2016-03-17 23:58:03 +00:00
Benjamin Kramer 1082fa66a5 Revert "Recommitted r261633 "Supporting all entities declared in lexical scope in LLVM debug info." After fixing PR26715 at r263379."
This reverts commit r263424. Breaks self-host.

llvm-svn: 263437
2016-03-14 14:58:36 +00:00
Amjad Aboud ab0378b16c Recommitted r261633 "Supporting all entities declared in lexical scope in LLVM debug info."
After fixing PR26715 at r263379.

llvm-svn: 263424
2016-03-14 12:03:20 +00:00
Hans Wennborg d3661cd140 Revert r261633 "Supporting all entities declared in lexical scope in LLVM debug info."
This and the corresponding Clang change caused PR26715.

llvm-svn: 261671
2016-02-23 19:17:03 +00:00
Amjad Aboud fc8f296782 Supporting all entities declared in lexical scope in LLVM debug info.
Differential Revision: http://reviews.llvm.org/D15976

llvm-svn: 261633
2016-02-23 13:36:51 +00:00
Peter Collingbourne 7c384ccea2 DwarfDebug: emit type units immediately.
Rather than storing type units in a vector and emitting them at the end
of code generation, emit them immediately and destroy them, reclaiming the
memory we were using for their DIEs.

In one benchmark carried out against Chromium's 50 largest (by bitcode
file size) translation units, total peak memory consumption with type units
decreased by median 17%, or by 7% when compared against disabling type units.

Tested using check-{llvm,clang}, the GDB 7.5 test suite (with
'-fdebug-types-section') and by eyeballing llvm-dwarfdump output on those
Chromium translation units with split DWARF both disabled and enabled, and
verifying that the only changes were to addresses and abbreviation ordering.

Differential Revision: http://reviews.llvm.org/D17118

llvm-svn: 260578
2016-02-11 19:57:46 +00:00
Keno Fischer b011c63d19 [DIBuilder] Make createReferenceType take size and align
Summary: Since we're passing references to dbg.value as pointers,
we need to have the frontend properly declare their sizes and
alignments (as it already does for regular pointers) in preparation
for my upcoming patch to have the verifer check that the sizes agree.

Also augment the backend logic that skips actually emitting this
information into DWARF such that it also handles reference types.

Reviewers: aprantl, dexonsmith, dblaikie

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D14275

llvm-svn: 253186
2015-11-16 07:57:32 +00:00
David Blaikie c9ad9191a7 DebugInfo: Include the decl_line/decl_file in subprogram definitions if they differ from those in the declaration
This is handy for some AutoFDO stuff, and seems like a minor improvement
to correctness (otherwise a debug info consumer might think the decl
line/file of the def was the same as that of the declaration - though
what a consumer might use that for, I'm not sure - maybe "list <func>"
would've misbehaved with the old behavior?) and at a minor cost (in my
experiment, with fission, without type units, without compression, 0.01%
growth in debug info in the executable/objects, 0.02% growth in the .dwo
files).

llvm-svn: 249487
2015-10-07 00:04:16 +00:00
Adrian Prantl d209500fd5 Debug Info: Allow a DIModule to appear as the scope of other entities.
llvm-svn: 247304
2015-09-10 17:13:58 +00:00
Duncan P. N. Exon Smith 0660bcda53 AsmPrinter: Allow null subroutine type
Currently the DWARF backend requires that subprograms have a type, and
the type is ignored if it has an empty type array.  The long term
direction here -- see PR23079 -- is instead to skip the type entirely if
there's no valid type.

It turns out we have cases in tree of missing types on subprograms, but
since they're not referenced by compile units, the backend never crashes
on them.  One option would be to add a Verifier check that subprograms
have types, and fix the bitrot.  However, this is a fair bit of churn
(20-30 testcases) that would be reversed anyway by PR23079.

I found this inconsistency because of a WIP patch and upgrade script for
PR23367 that started crashing on test/DebugInfo/2010-10-01-crash.ll.
This commit updates the testcase to reference the subprogram from the
compile unit, and fixes the resulting crash (in line with the direction
of PR23079).  This also updates `DIBuilder` to stop assuming a non-null
pointer for the subroutine types.

llvm-svn: 246333
2015-08-28 21:38:24 +00:00
Paul Robinson 78046b49a9 Make DW_AT_[MIPS_]linkage_name optional, and off by default for SCE.
Mangled "linkage" names can be huge, and if the debugger (or other
tools) have no use for them, the size savings can be very impressive
(on the order of 40%).

Add one test for controlling behavior, and modify a number of tests to
either stop using linkage names, or make llc emit them (so these tests
will still run when the default triple is for PS4).

Differential Revision: http://reviews.llvm.org/D11374

llvm-svn: 244678
2015-08-11 21:36:45 +00:00
Duncan P. N. Exon Smith 55a868a0f6 AsmPrinter: Take DIEValueList in some DwarfUnit API, NFC
Take `DIEValueList` instead of `DIE` so that `DIEBlock` and `DIELoc` can
stop inheriting from `DIE` in a future commit.

llvm-svn: 243855
2015-08-02 20:44:46 +00:00
Duncan P. N. Exon Smith ed013cd221 DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

llvm-svn: 243774
2015-07-31 18:58:39 +00:00
Pete Cooper 7679afda82 Use make_range(rbegin(), rend()) to allow foreach loops. NFC.
Instead of the pattern

for (auto I = x.rbegin(), E = x.end(); I != E; ++I)

we can use make_range to construct the reverse range and iterate using
that instead.

llvm-svn: 243163
2015-07-24 21:13:43 +00:00
Duncan P. N. Exon Smith acd8cf8582 AsmPrinter: Use DICompositeType in updateAcceleratorTables(), NFC
`DISubroutineType` is impossible at this `dyn_cast` site, since we're
only dealing with named types and `DISubroutineType` cannot be named.
Strengthen the `dyn_cast` to `DICompositeType`.

llvm-svn: 243157
2015-07-24 20:45:26 +00:00
Duncan P. N. Exon Smith 89c5e6ff49 DI: Clarify isUnsignedDIType(), NFC
Refactor `isUnsignedDIType()` to deal with `DICompositeType` explicitly.
Since `DW_TAG_subroutine_type` isn't handled here (the assertions about
tags rule it out), this allows strengthening the `dyn_cast` to
`DIDerivedType`.

Besides making the code clearer, this it removes a use of
`DIDerivedTypeBase`.

llvm-svn: 243148
2015-07-24 19:42:12 +00:00
Duncan P. N. Exon Smith 6ac940db19 DI: Only DICompositeType has getElements(), NFC
There is an assertion inside `DICompositeTypeBase::getElements()` that
`this` is not a `DISubroutineType`, leaving only `DICompositeType`.
Make that clear at the call sites.

llvm-svn: 243134
2015-07-24 18:17:17 +00:00
Adrian Prantl ee5feafc0f Debug Info: Add basic support for external types references.
This is a necessary prerequisite for bootstrapping the emission
of debug info inside modules.

- Adds a FlagExternalTypeRef to DICompositeType.
  External types must have a unique identifier.
- External type references are emitted using a forward declaration
  with a DW_AT_signature([DW_FORM_ref_sig8]) based on the UID.

http://reviews.llvm.org/D9612

llvm-svn: 242302
2015-07-15 17:01:41 +00:00
David Blaikie d51dea67b3 Revert "[DWARF] Fix debug info generation for function static variables, typedefs, and records"
Caused PR24008

This reverts commit 37cb5f1c2db9f42d29f26b215585f56bb64ae4f5.

llvm-svn: 241176
2015-07-01 18:07:16 +00:00
Michael Kuperstein 01e8185c31 [DWARF] Fix debug info generation for function static variables, typedefs, and records
Function static variables, typedefs and records (class, struct or union) declared inside
a lexical scope were associated with the function as their parent scope, rather than the
lexical scope they are defined or declared in.

This fixes PR19238

Patch by: amjad.aboud@intel.com
Differential Revision: http://reviews.llvm.org/D9758

llvm-svn: 241153
2015-07-01 12:33:11 +00:00
Adrian Prantl 08a388ba8f Debug info: Add dwarf backend support for DIModule.
rdar://problem/20965932

llvm-svn: 241034
2015-06-30 02:13:04 +00:00
Adrian Prantl cb53eedc79 Revert "Debug Info: One more bitfield bugfix. While yesterday's r240853 fixed"
This reverts commit 240890. Breaking the gdb buildbot.

llvm-svn: 240893
2015-06-27 21:55:00 +00:00
Adrian Prantl 57c7a62b97 Debug Info: One more bitfield bugfix. While yesterday's r240853 fixed
the DW_AT_bit_offset computation, the byte offset is in fact also
endian-dependent as it needs to point to the storage unit containing the
most-significant bit of the the bitfield.
I'm so looking forward to emitting the endian-agnostic DWARF 3 version
instead.

llvm-svn: 240890
2015-06-27 20:12:43 +00:00
Adrian Prantl d3da8caf67 Debug Info: Fix a bug in the DW_AT_bit_offset calculation that would
result in negative offsets and attempt a better job at documenting
the algorithm.

rdar://21082998

llvm-svn: 240853
2015-06-26 23:31:27 +00:00
Adrian Prantl 06b298e4b6 Debug Info: Clarify the documentation for bitfields emission.
llvm-svn: 240835
2015-06-26 21:27:30 +00:00
Duncan P. N. Exon Smith 827200c822 AsmPrinter: Use an intrusively linked list for DIE::Children
Replace the `std::vector<>` for `DIE::Children` with an intrusively
linked list.  This is a strict memory improvement: it requires no
auxiliary storage, and reduces `sizeof(DIE)` by one pointer.  It also
factors out the DIE-related malloc traffic.

This drops llc memory usage from 735 MB down to 718 MB, or ~2.3%.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 240736
2015-06-25 23:52:10 +00:00
Duncan P. N. Exon Smith 4fb1f9cda6 AsmPrinter: Convert DIE::Values to a linked list
Change `DIE::Values` to a singly linked list, where each node is
allocated on a `BumpPtrAllocator`.  In order to support `push_back()`,
the list is circular, and points at the tail element instead of the
head.  I abstracted the core list logic out to `IntrusiveBackList` so
that it can be reused for `DIE::Children`, which also cares about
`push_back()`.

This drops llc memory usage from 799 MB down to 735 MB, about 8%.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 240733
2015-06-25 23:46:41 +00:00
Rafael Espindola 857546e7e0 Rename and improve emitSectionOffset.
Different object formats represent references from dwarf in different ways.

ELF uses a relocation to the referenced point (except for .dwo) and
COFF/MachO use the offset of the referenced point inside its section.

This patch renames emitSectionOffset because

* It doesn't produce an offset on ELF.
* It changes behavior depending on how DWARF is represented, so adding
dwarf to its name is probably a good thing.

The patch also adds an option to force the use of offsets.That avoids
funny looking code like

  if (!UseOffsets)
    Asm->emitSectionOffset....

It was correct, but read as if the ! was inverted.

llvm-svn: 239866
2015-06-16 23:22:02 +00:00
Adrian Prantl 8ff53b3cda Debug Info IR: Switch DIObjCProperty to use DITypeRef.
This is a prerequisite for turning on ODR type uniquing for ObjC++.

rdar://problem/21377883

llvm-svn: 239780
2015-06-15 23:18:03 +00:00
Duncan P. N. Exon Smith 6289892c20 AsmPrinter: Return added DIE from DIE::addChild()
Change `DIE::addChild()` to return a reference to the just-added node,
and update consumers to use it directly.  An upcoming commit will
abstract away (and eventually change) the underlying storage of
`DIE::Children`.

llvm-svn: 238372
2015-05-27 22:59:03 +00:00
Duncan P. N. Exon Smith e7e1d0c706 Reapply "AsmPrinter: Change DIEValue to be stored by value"
This reverts commit r238350, effectively reapplying r238349 after fixing
(all?) the problems, all somehow related to how I was using
`AlignedArrayCharUnion<>` inside `DIEValue`:

  - MSVC can only handle `sizeof()` on types, not values.  Change the
    assert.
  - GCC doesn't know the `is_trivially_copyable` type trait.  Instead of
    asserting it, add destructors.
  - Call placement new even when constructing POD (i.e., the pointers).
  - Instead of copying the char buffer, copy the casted classes.

I've left in a couple of `static_assert`s that I think both MSVC and GCC
know how to handle.  If the bots disagree with me, I'll remove them.

  - Check that the constructed type is either standard layout or a
    pointer.  This protects against a programming error: we really want
    the "small" `DIEValue`s to be small and simple, so don't
    accidentally change them not to be.
  - Similarly, check that the size of the buffer is no bigger than a
    `uint64_t` or a pointer.  (I thought checking against
    `sizeof(uint64_t)` would be good enough, but Chandler suggested that
    pointers might sometimes be bigger than that in the context of
    sanitizers.)

I've also committed r238359 in the meantime, which introduces a
DIEValue.def to simplify dispatching between the various types (thanks
to a review comment by David Blaikie).  Without that, this commit would
be almost unintelligible.

Here's the original commit message:
--
Change `DIEValue` to be stored/passed/etc. by value, instead of
reference.  It's now a discriminated union, with a `Val` field storing
the actual type.  The classes that used to inherit from `DIEValue` no
longer do.  There are two categories of these:

  - Small values fit in a single pointer and are stored by value.
  - Large values require auxiliary storage, and are stored by reference.

The only non-mechanical change is to tools/dsymutil/DwarfLinker.cpp.  It
was relying on `DIEInteger`s being passed around by reference, so I
replaced that assumption with a `PatchLocation` type that stores a safe
reference to where the `DIEInteger` lives instead.

This commit causes a temporary regression in memory usage, since I've
left merging `DIEAbbrevData` into `DIEValue` for a follow-up commit.  I
measured an increase from 845 MB to 879 MB, around 3.9%.  The follow-up
drops it lower than the starting point, and I've only recently brought
the memory this low anyway, so I'm committing these changes separately
to keep them incremental.  (I also considered swapping the commits, but
the other one first would cause a lot more code churn.)

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
--

llvm-svn: 238362
2015-05-27 22:14:58 +00:00
Duncan P. N. Exon Smith 583bc03829 Revert "AsmPrinter: Change DIEValue to be stored by value"
This reverts commit r238349, since it caused some errors on bots:
  - std::is_trivially_copyable isn't available until GCC 5.0.
  - It was complaining about strict aliasing with my use of
    ArrayCharUnion.

llvm-svn: 238350
2015-05-27 19:30:27 +00:00
Duncan P. N. Exon Smith 7735b48a8b AsmPrinter: Change DIEValue to be stored by value
Change `DIEValue` to be stored/passed/etc. by value, instead of
reference.  It's now a discriminated union, with a `Val` field storing
the actual type.  The classes that used to inherit from `DIEValue` no
longer do.  There are two categories of these:

  - Small values fit in a single pointer and are stored by value.
  - Large values require auxiliary storage, and are stored by reference.

The only non-mechanical change is to tools/dsymutil/DwarfLinker.cpp.  It
was relying on `DIEInteger`s being passed around by reference, so I
replaced that assumption with a `PatchLocation` type that stores a safe
reference to where the `DIEInteger` lives instead.

This commit causes a temporary regression in memory usage, since I've
left merging `DIEAbbrevData` into `DIEValue` for a follow-up commit.  I
measured an increase from 845 MB to 879 MB, around 3.9%.  The follow-up
drops it lower than the starting point, and I've only recently brought
the memory this low anyway, so I'm committing these changes separately
to keep them incremental.  (I also considered swapping the commits, but
the other one first would cause a lot more code churn.)

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 238349
2015-05-27 19:22:50 +00:00
Duncan P. N. Exon Smith f73bcf4020 AsmPrinter: Make DIEString small
Expose the `DwarfStringPool` entry in a header, and store a pointer to
it directly in `DIEString`.  Instead of choosing at creation time how to
emit it, use the `dwarf::Form` to determine that at emission time.
Besides avoiding the other `DIEValue`, this shaves two pointers off of
`DIEString`; the data is now a single pointer.  This is a nice cleanup
on its own -- and drops memory usage from 861 MB down to 853 MB, around
0.9% -- but it's also preparation for passing `DIEValue`s by value.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 238117
2015-05-24 16:40:47 +00:00
Duncan P. N. Exon Smith 1a65e4ade4 AsmPrinter: Emit the DwarfStringPool offset directly when possible
Change `DwarfStringPool` to calculate byte offsets on-the-fly, and
update `DwarfUnit::getLocalString()` to use a `DIEInteger` instead of a
`DIEDelta` when Dwarf doesn't use relocations (i.e., Mach-O).  This
eliminates another call to `EmitLabelDifference()`, and drops memory
usage from 865 MB down to 861 MB, around 0.5%.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 238114
2015-05-24 16:14:59 +00:00
Rafael Espindola 0709a7bd1a Move alignment from MCSectionData to MCSection.
This starts merging MCSection and MCSectionData.

There are a few issues with the current split between MCSection and
MCSectionData.

* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.

* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.

* It makes it harder to remember where each item is.

The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.

Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.

llvm-svn: 237936
2015-05-21 19:20:38 +00:00
Pete Cooper 477300d333 Revert "Add bool to DebugLocDwarfExpression to control emitting comments."
This reverts commit 0037b6bcbc874aa1b93d7ce3ad8dba3753ee2d9d (r237827).

David Blaikie suggested some alternatives to this which are better.  Reverting to apply a better solution later.

llvm-svn: 237849
2015-05-20 22:37:48 +00:00
Pete Cooper 35522001fa Add bool to DebugLocDwarfExpression to control emitting comments.
DebugLocDwarfExpression::EmitOp was creating temporary strings by concatenating Twine's.

When emitting to object files, these comments are thrown away.

This commit adds a boolean to the constructor of the DwarfExpression to control whether it will actually emit
any comments.  This prevents it from even generating the temporary comments which would have been thrown away anyway.

llvm-svn: 237827
2015-05-20 19:50:03 +00:00
Duncan P. N. Exon Smith a9308c49ef IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

llvm-svn: 236120
2015-04-29 16:38:44 +00:00
Lang Hames 9ff69c8f4d [AsmPrinter] Make AsmPrinter's OutStreamer member a unique_ptr.
AsmPrinter owns the OutStreamer, so an owning pointer makes sense here. Using a
reference for this is crufty.

llvm-svn: 235752
2015-04-24 19:11:51 +00:00
Duncan P. N. Exon Smith aa861aa483 DebugInfo: Remove DIArray and DITypeArray typedefs
Remove the `DIArray` and `DITypeArray` typedefs, preferring the
underlying types (`DebugNodeArray` and `MDTypeRefArray`, respectively).

llvm-svn: 235413
2015-04-21 20:07:38 +00:00
Duncan P. N. Exon Smith 60635e39b6 DebugInfo: Drop rest of DIDescriptor subclasses
Delete the remaining subclasses of (the already deleted) `DIDescriptor`.
Part of PR23080.

llvm-svn: 235404
2015-04-21 18:44:06 +00:00
Duncan P. N. Exon Smith 2fbe13540a DebugInfo: Delete subclasses of DIScope
Delete subclasses of (the already defunct) `DIScope`, updating users to
use the raw pointers from the `Metadata` hierarchy directly.

llvm-svn: 235356
2015-04-20 22:10:08 +00:00
Duncan P. N. Exon Smith c62468859a DebugInfo: Delete old subclasses of DIType
Delete subclasses of (the already deleted) `DIType` in favour of
directly using pointers from the `Metadata` hierarchy.

While `DICompositeType` wraps `MDCompositeTypeBase` and `DIDerivedType`
wraps `MDDerivedTypeBase`, most uses of each really meant the more
specific `MDCompositeType` and `MDDerivedType`.

llvm-svn: 235351
2015-04-20 21:17:32 +00:00
Duncan P. N. Exon Smith 698df36ab7 DwarfUnit: Split MDSubroutineType version of constructTypeDIE()
The version of `constructTypeDIE()` for `MDSubroutineType` is unrelated
to (and has different callers than) the `MDCompositeType`.  Split the
two in half.

This simplifies an upcoming patch to delete `DICompositeType`.  There
shouldn't be any real functionality change here.  `createTypeDIE()` is
`cast<>`'ing where it didn't need to before, but that function in turn
is only called for true `MDCompositeType`s.

llvm-svn: 235349
2015-04-20 21:04:33 +00:00
Duncan P. N. Exon Smith d89ef16aa9 DwarfUnit: Cleanup comments
Update comment style in `DwarfUnit`.

  - Drop duplicated comments at definition, and update the comments at
    the declaration where the definition comments looked newer or more
    complete.
  - Drop the `functionName -` prefix.
  - Add `\brief` in a few places.
  - Remove a few comments entirely that weren't adding value (just
    turned the function name and arguments into a sentence).

llvm-svn: 235345
2015-04-20 20:29:51 +00:00
Duncan P. N. Exon Smith 9928a909c6 DebugInfo: Remove DIType
This is the last major parent class, so I'll probably start deleting
classes in batches now.  Looks like many of the references to the DI*
hierarchy were updated organically along the way.

llvm-svn: 235331
2015-04-20 18:52:06 +00:00
Duncan P. N. Exon Smith be9e4fe768 DebugInfo: Remove DIScope
Replace uses of `DIScope` with `MDScope*`.  There was one spot where
I've left an `MDScope*` uninitialized (where `DIScope` would have been
default-initialized to `nullptr`) -- this is intentional, since the
if/else that follows should unconditional assign it to a value.

llvm-svn: 235327
2015-04-20 18:32:29 +00:00
Duncan P. N. Exon Smith 848af387d8 DebugInfo: Remove typedefs for DITypeRef, etc.
Remove typedefs for type refs:

  - DITypeRef => MDTypeRef
  - DIScopeRef => MDScopeRef
  - DIDescriptorRef => DebugNodeRef

llvm-svn: 235323
2015-04-20 18:20:03 +00:00
Duncan P. N. Exon Smith 7c60f20e49 DebugInfo: Delete DIDescriptor (but not its subclasses)
Delete `DIDescriptor` and update the remaining users.  I'll follow-up by
deleting subclasses in manageable groups (top-down).

llvm-svn: 235248
2015-04-18 00:35:36 +00:00
Duncan P. N. Exon Smith f15c6f8032 DebugInfo: Gut DIDescriptor
PR23080 is almost finished.  With this commit, there's no consequential
API in `DIDescriptor` and its subclasses.  What's left?

  - Default-constructed to `nullptr`.
  - Handy `const_cast<>` (constructed from `const`, but accessors are
    non-`const`).

I think the safe way to catch those is to delete the classes and fix
compile errors.  That'll be my next step, after I delete the `DITypeRef`
(etc.) wrapper around `MDTypeRef`.

llvm-svn: 235069
2015-04-16 01:53:33 +00:00
Duncan P. N. Exon Smith b273d06b63 DebugInfo: Gut DIScope, DIEnumerator and DISubrange
The only class the still has API left is `DIDescriptor` itself.

llvm-svn: 235067
2015-04-16 01:37:00 +00:00
Duncan P. N. Exon Smith b105564015 DebugInfo: Gut DIType and subclasses
Continuing PR23080, gut `DIType` and its various subclasses, leaving
behind thin wrappers around the pointer types in the new debug info
hierarchy.

llvm-svn: 235064
2015-04-16 01:01:28 +00:00
Duncan P. N. Exon Smith 1d1a8e00b8 DebugInfo: Remove unnecessary API from DIDerivedType and DIType
Remove the accessors of `DIDerivedType` that downcast to
`MDDerivedType`, shifting the `cast<MDDerivedType>` into the callers.
Also remove `DIType::isValid()`, which is really just a check against
`nullptr` at this point.

llvm-svn: 235059
2015-04-15 23:49:09 +00:00
Duncan P. N. Exon Smith 537b4a8159 DebugInfo: Gut DISubprogram and DILexicalBlock*
Gut the `DIDescriptor` wrappers around `MDLocalScope` subclasses.  Note
that `DILexicalBlock` wraps `MDLexicalBlockBase`, not `MDLexicalBlock`.

llvm-svn: 234850
2015-04-14 03:40:37 +00:00
Duncan P. N. Exon Smith 20caafbfd6 DebugInfo: Gut DINamespace and DITemplate*Parameter
Continue gutting `DIDescriptor` subclasses, turning them into
as-bare-as-possible pointer wrappers.

llvm-svn: 234843
2015-04-14 03:01:27 +00:00
Duncan P. N. Exon Smith 7348ddaa74 DebugInfo: Gut DIVariable and DIGlobalVariable
Gut all the non-pointer API from the variable wrappers, except an
implicit conversion from `DIGlobalVariable` to `DIDescriptor`.  Note
that if you're updating out-of-tree code, `DIVariable` wraps
`MDLocalVariable` (`MDVariable` is a common base class shared with
`MDGlobalVariable`).

llvm-svn: 234840
2015-04-14 02:22:36 +00:00
Duncan P. N. Exon Smith de8e427394 DebugInfo: Gut DIObjCProperty and DIImportedEntity
Gut a couple more classes in the DIDescriptor hierarchy.  Leave behind
an implicit conversion to `DIDescriptor`, the old base class.

llvm-svn: 234836
2015-04-14 01:46:44 +00:00
Duncan P. N. Exon Smith 26e1cda1f4 DebugInfo: Remove DIObjCProperty attribute accessors, NFC
There's only one user of the various `DIObjCProperty::is*Property()`
accessors -- `DwarfUnit::constructTypeDIE()` -- and it's just using the
reverse logic to reconstruct the bitfield.  Drop this API and simplify
the only caller.

llvm-svn: 234818
2015-04-13 23:55:01 +00:00
Duncan P. N. Exon Smith 9a597ef199 Revert "Try a third time to fix MSVC build after r234290"
This reverts commit r234295 (and r234294 and r234292 before it).  I
removed the implicit conversion to `MDTuple*` r234326, so there's no
longer an ambiguity in `operator[]()`.

I think MSVC should accept the original code now...

llvm-svn: 234335
2015-04-07 18:07:41 +00:00
Duncan P. N. Exon Smith 1c0844bdfb Try a third time to fix MSVC build after r234290
I have no idea what MSVC means with its error text here :(.

http://lab.llvm.org:8011/builders/sanitizer-windows/builds/2310

llvm-svn: 234295
2015-04-07 05:03:47 +00:00
Duncan P. N. Exon Smith 8a4569bd2b Try again to fix MSVC build after r234290
Still failing:

http://lab.llvm.org:8011/builders/sanitizer-windows/builds/2309

llvm-svn: 234294
2015-04-07 04:49:13 +00:00
Duncan P. N. Exon Smith 4ddfd73aa1 Try to fix MSVC build after r234290
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/2308

llvm-svn: 234292
2015-04-07 04:33:42 +00:00
Duncan P. N. Exon Smith 000fa2c646 DebugInfo: Remove DITypedArray<>, replace with typedefs
Replace all uses of `DITypedArray<>` with `MDTupleTypedArrayWrapper<>`
and `MDTypeRefArray`.  The APIs are completely different, but the
provided functionality is the same: treat an `MDTuple` as if it's an
array of a particular element type.

To simplify this patch a bit, I've temporarily typedef'ed
`DebugNodeArray` to `DIArray` and `MDTypeRefArray` to `DITypeArray`.
I've also temporarily conditionalized the accessors to check for null --
eventually these should be changed to asserts and the callers should
check for null themselves.

There's a tiny accompanying patch to clang.

llvm-svn: 234290
2015-04-07 04:14:33 +00:00
Duncan P. N. Exon Smith e686f1591f CodeGen: Stop using DIDescriptor::is*() and auto-casting
Same as r234255, but for lib/CodeGen and lib/Target.

llvm-svn: 234258
2015-04-06 23:27:40 +00:00
Duncan P. N. Exon Smith a5099dce62 DebugInfo: Remove DIDescriptor::Verify()
Remove `DIDescriptor::Verify()` and the `Verify()`s from subclasses.
They had already been gutted, and just did an `isa<>` check.

In a couple of cases I've temporarily dropped the check entirely, but
subsequent commits are going to disallow conversions to the
`DIDescriptor`s directly from `MDNode`, so the checks will come back in
another form soon enough.

llvm-svn: 234201
2015-04-06 19:49:39 +00:00
Eric Christopher cd53d6eda7 Change getISAEncoding to use the target triple to determine
thumb-ness similar to the rest of the Module level asm printing
infrastructure as debug info finalization happens after the function
may be missing.

llvm-svn: 232875
2015-03-21 03:13:01 +00:00
Paul Robinson 857b4434df Emit correct linkage-name attribute based on DWARF version.
There are still 4 tests that check for DW_AT_MIPS_linkage_name,
because they specify DWARF 2 or 3 in the module metadata. So, I didn't
create an explicit version-based test for the attribute.

Differential Revision: http://reviews.llvm.org/D8227

llvm-svn: 231880
2015-03-10 22:44:45 +00:00
Adrian Prantl 51233680ae Change the datatype of DwarfExpression::Emit(Un)Signed to (u)int64_t
so it matches the one used by ByteStreamer::Emit(U|S)LEB128.

llvm-svn: 231823
2015-03-10 19:23:37 +00:00
Rafael Espindola 063d725fd7 Store an optional section start label in MCSection.
This makes code that uses section relative expressions (debug info) simpler and
less brittle.

This is still a bit awkward as the symbol is created late and has to be
stored in a mutable field.

I will move the symbol creation earlier in the next patch.

llvm-svn: 231802
2015-03-10 16:58:10 +00:00
Rafael Espindola 3c31114824 Move label creation close to emission. NFC.
llvm-svn: 231744
2015-03-10 03:11:11 +00:00
Adrian Prantl b846acc6c6 Revert "Revert "For the dwarf expression code get the subtarget off of the current""
This reapplies r230990 without modifications.

llvm-svn: 231024
2015-03-02 22:02:36 +00:00
Adrian Prantl 92da14b244 Refactor DebugLocDWARFExpression so it doesn't require access to the
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.

Ought to be NFC, but it does slightly alter the output format of the
textual assembly.

This reapplies 230930 without the assertion in DebugLocEntry::finalize()
because not all Machine registers can be lowered into DWARF register
numbers and floating point constants cannot be expressed.

llvm-svn: 231023
2015-03-02 22:02:33 +00:00
Adrian Prantl 2185aa179d Revert "Refactor DebugLocDWARFExpression so it doesn't require access to the"
This reverts commit 230975 to investigate buildbot breakage.

llvm-svn: 231004
2015-03-02 20:01:54 +00:00
Adrian Prantl abb9192652 Revert "For the dwarf expression code get the subtarget off of the current"
This reverts commit 230990 because also reverting 230975.

llvm-svn: 231003
2015-03-02 20:01:47 +00:00
Eric Christopher d8cacd2e97 For the dwarf expression code get the subtarget off of the current
MachineFunction.

llvm-svn: 230990
2015-03-02 19:01:47 +00:00
Adrian Prantl d50bca7314 Refactor DebugLocDWARFExpression so it doesn't require access to the
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.

Ought to be NFC, but it does slightly alter the output format of the
textual assembly.

This reapplies 230930 with a relaxed assertion in DebugLocEntry::finalize()
that allows for empty DWARF expressions for constant FP values.

llvm-svn: 230975
2015-03-02 17:21:06 +00:00
Nico Weber 968ceddca9 Revert r230930, it caused PR22747.
llvm-svn: 230932
2015-03-02 04:37:11 +00:00
Adrian Prantl e2c9e64532 Refactor DebugLocDWARFExpression so it doesn't require access to the
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.

Ought to be NFC, but it does slightly alter the output format of the
textual assembly.

llvm-svn: 230930
2015-03-02 02:38:18 +00:00
Eric Christopher a49d68e078 Make the ARM AsmPrinter independent of global subtarget
initialization. Initialize the subtarget once per function and
migrate Emit{Start|End}OfAsmFile to either use attributes on the
TargetMachine or get information from the subtarget we'd use
for assembling. One bit (getISAEncoding) touched the general
AsmPrinter and the debug output. Handle this one by passing
the function for the subprogram down and updating all callers
and users.

The top-level-ness of the ARM attribute output for assembly is,
by nature, contrary to how we'd want to do this for an LTO
situation where we have multiple cpu architectures so this
solution is good enough for now.

llvm-svn: 229528
2015-02-17 20:02:32 +00:00
Bruce Mitchener 7e575ed1ea Add more DWARF 5 language constants.
Differential Revision: http://reviews.llvm.org/D7430

llvm-svn: 228487
2015-02-07 06:35:30 +00:00
Adrian Prantl 9013c4b3b1 Debug Info: Relax assertion in isUnsignedDIType() to allow floats to be
described by integer constants. This is a bit ugly, but if the source
language allows arbitrary type casting, the debug info must follow suit.

For example:
  void foo() {
    float a;
    *(int *)&a = 0;
  }
For the curious: SROA replaces the float alloca with an i32 alloca, which
is then optimized away and described via dbg.value(i32 0, ...).

llvm-svn: 227827
2015-02-02 18:31:58 +00:00
David Blaikie e245228903 Add description to assert
llvm-svn: 227291
2015-01-28 02:43:15 +00:00
David Blaikie fa1a3c7cf5 PR22356: DebugInfo: Handle the size of a member where the type of that member is a typedef (or other sugar) of a declaration.
llvm-svn: 227290
2015-01-28 02:34:53 +00:00
Adrian Prantl 577feba44b Debug Info / PR22309: Allow union types to be emitted as unsigned constants.
llvm-svn: 226919
2015-01-23 18:01:39 +00:00
Chandler Carruth d9903888d9 [cleanup] Re-sort all the #include lines in LLVM using
utils/sort_includes.py.

I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.

llvm-svn: 225974
2015-01-14 11:23:27 +00:00
Adrian Prantl 658676c3ea Debug Info: Move DIEDwarfExpression into DwarfExpression.h because it
needs to be accessed from both DwarfCompileUnit.cpp and DwarfUnit.cpp.

NFC.

llvm-svn: 225898
2015-01-14 01:01:22 +00:00
Adrian Prantl 8995f5c92f Debug Info: Turn DIExpression::getFrameRegister() into an isFrameRegister()
function.

NFC.

llvm-svn: 225846
2015-01-13 23:10:43 +00:00
Adrian Prantl a4c30d6509 Make DwarfExpression store the AsmPrinter instead of the TargetMachine.
NFC.

llvm-svn: 225731
2015-01-12 23:36:56 +00:00
Adrian Prantl 0e6ffb9d0d Debug Info: Implement DwarfUnit::addRegisterOpPiece() using DwarfExpression.
NFC.

llvm-svn: 225717
2015-01-12 22:37:16 +00:00
Adrian Prantl 00dbc2a7d3 Debug Info: Implement DwarfUnit::addRegisterOffset using DwarfExpression.
No functional change.

llvm-svn: 225707
2015-01-12 22:19:26 +00:00
Adrian Prantl d88af278b9 Update a comment.
llvm-svn: 225399
2015-01-07 21:35:13 +00:00
Adrian Prantl 3dd48c6fde Debug info: Allow aggregate types to be described by constants.
llvm-svn: 225378
2015-01-07 20:48:58 +00:00
Adrian Prantl 3026a54aa2 Debug Info: In symmetry to DW_TAG_pointer_type, do not emit the byte size
of a DW_TAG_ptr_to_member_type.
This restores the behavior from before r224780-r224781.

llvm-svn: 224799
2014-12-24 01:17:51 +00:00
Adrian Prantl cf44e7870b Explain why LLVM is emitting a DW_AT_containing_type inside of a class.
llvm-svn: 224555
2014-12-19 00:01:20 +00:00
David Blaikie 8b979f01c6 PR21875: codegen for non-type template parameters of nullptr_t type
llvm-svn: 224399
2014-12-17 00:43:22 +00:00
Duncan P. N. Exon Smith 5bf8fef580 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

llvm-svn: 223802
2014-12-09 18:38:53 +00:00
Eric Christopher d1fb7e4590 These two calls were grabbing the same register info. Unify them.
llvm-svn: 223502
2014-12-05 19:23:55 +00:00
Adrian Prantl ab255fcd09 Cleanup: Calls to getDwarfRegNum() may actually fail, if there is
no DWARF register number mapping, or if the register was a virtual
register that was never materialized. Previously, we would just emit a
bogus location, after this patch we don't emit a location at all by
doing an early exit.

After my bugfix in r223401 today, this doesn't actually happen on any
target that I tested this with, but it's still preferable to make the
possibility of a failure explicit.

llvm-svn: 223428
2014-12-05 01:02:46 +00:00
David Blaikie 3a443c29b9 Provide gmlt-like inline scope information in the skeleton CU to facilitate symbolication without needing the .dwo files
Clang -gsplit-dwarf self-host -O0, binary increases by 0.0005%, -O2,
binary increases by 25%.

A large binary inside Google, split-dwarf, -O0, and other internal flags
(GDB index, etc) increases by 1.8%, optimized build is 35%.

The size impact may be somewhat greater in .o files (I haven't measured
that much - since the linked executable -O0 numbers seemed low enough)
due to relocations. These relocations could be removed if we taught the
llvm-symbolizer to handle indexed addressing in the .o file (GDB can't
cope with this just yet, but GDB won't be reading this info anyway).
Also debug_ranges could be shared between .o and .dwo, though ideally
debug_ranges would get a schema that could used index(+offset)
addressing, and move to the .dwo file, then we'd be back to sharing
addresses in the address pool again.

But for now, these sizes seem small enough to go ahead with this.

Verified that no other DW_TAGs are produced into the .o file other than
subprograms and inlined_subroutines.

llvm-svn: 221306
2014-11-04 22:12:25 +00:00
David Blaikie 9bfd7a9f43 Move cross-unit DIE caching to the DwarfFile level, so it doesn't interfere with fission-gmlt data and produce skeleton<>full unit cross referencing.
llvm-svn: 221305
2014-11-04 22:12:18 +00:00
David Blaikie cafd962d97 Add DwarfUnit::isDwoUnit and use it to generalize string creation
Currently we only need to emit skeleton strings into the CU header and
we do this by explicitly calling "addLocalString". With gmlt-in-fission,
we'll be emitting a bunch of other strings from other codepaths where
it's not statically known that these strings will be local or not.

Introduce a virtual function to indicate whether this unit is a DWO unit
or not (I'm not sure if we have a good term for this, the
opposite/alternative to 'skeleton' unit) and use that to generalize the
string emission logic so that strings can be correctly emitted in both
the skeleton and dwo unit when in split dwarf mode.

And to demonstrate that this works, switch the existing special callers
of addLocalString in the skeleton builder to addString - and they still
work. Yay.

llvm-svn: 221094
2014-11-02 08:51:37 +00:00
David Blaikie 279c451c0b Remove the last mention of LineTablesOnly from DwarfUnit, sinking it into DwarfCompileUnit
This is a useful distinction/invariant/delination to make because
LineTablesOnly mode is never relevant to type units, so it's clear that
we're not doing weird line-tables-only-with-types by making this API
choice.

It also lays the foundations nicely for adding gmlt-like data to fission
skeleton CUs while limiting the effects to CUs and not TUs.

llvm-svn: 221093
2014-11-02 08:18:06 +00:00
David Blaikie 3363a57c8e Sink DwarfUnit::applySubprogramAttributesToDefinition into DwarfCompileUnit
llvm-svn: 221092
2014-11-02 08:09:09 +00:00
David Blaikie 978020807a Sink DwarfUnit::addExpr into DwarfCompileUnit
llvm-svn: 221090
2014-11-02 07:11:55 +00:00
David Blaikie 02a6333ba7 Sink DwarfUnit::applyVariableAttributes into DwarfCompileUnit
llvm-svn: 221088
2014-11-02 07:06:51 +00:00
David Blaikie 4bc0881ac7 Sink DwarfUnit::addLocationList down into DwarfCompileUnit
llvm-svn: 221087
2014-11-02 07:03:19 +00:00
David Blaikie 77895fb276 Sink DwarfUnit::addComplexAddress down into DwarfCompileUnit
llvm-svn: 221086
2014-11-02 06:58:44 +00:00
David Blaikie f7435ee6ce Push DwarfUnit::addAddress down into DwarfCompileUnit
llvm-svn: 221085
2014-11-02 06:46:40 +00:00
David Blaikie 7d48be2b7b Sink DwarfUnit::addVariableAddress into DwarfCompileUnit since type units don't have variables
llvm-svn: 221084
2014-11-02 06:37:23 +00:00
David Blaikie 192b45c1ef DebugInfo: Sink accelerator table lists down (GlobalNames/Types) into DwarfCompileUnit
llvm-svn: 221083
2014-11-02 06:16:39 +00:00
David Blaikie 98cf172175 Add DwarfUnit::addGlobalType to match DwarfUnit::addGlobalName
(these will shortly become virtual, with a null implementation in
DwarfUnit (since type units don't have accelerator tables in the current
schema) and the current implementation down in DwarfCompileUnit, moving
the actual maps there too)

llvm-svn: 221082
2014-11-02 06:06:14 +00:00
David Blaikie 871c2d9d63 DebugInfo: Refactor index type DIE initialization by rolling it into the accessor
llvm-svn: 221080
2014-11-02 03:09:13 +00:00
David Blaikie f4bdc31271 Sink DwarfUnit::LabelBegin down into DwarfCompileUnit since that's the only place it's needed.
llvm-svn: 221075
2014-11-02 01:21:40 +00:00
David Blaikie ae57e66e36 Sink dwarf unit length emission down into DwarfUnit::emitHeader
This allows the CU label to be emitted only for compile units, as
they're the only ones that need it (so they can be referenced from
pubnames)

llvm-svn: 221072
2014-11-01 23:59:23 +00:00
David Blaikie 983bfea0d0 Remove DwarfUnit::LabelEnd in favor of computing the length of the section directly
This was a compile-unit specific label (unused in type units) and seems
unnecessary anyway when we can more easily directly compute the size of
the compile unit.

llvm-svn: 221067
2014-11-01 23:07:14 +00:00
David Blaikie a34568b220 Sink DwarfUnit::SectionSym into DwarfCompileUnit as it's only needed/used there.
llvm-svn: 221062
2014-11-01 20:06:28 +00:00
David Blaikie 7cbf58af15 Sink DwarfUnit::Skeleton down into DwarfCompileUnit
Type units no longer have skeletons and it's misleading to be able to
query for a type unit's skeleton (it might incorrectly lead one to
conclude that if a unit doesn't have a skeleton it's not in a .dwo
file... ).

llvm-svn: 221055
2014-11-01 18:18:07 +00:00
David Blaikie df1cca3a24 Remove some unnecessary casts.
llvm-svn: 220658
2014-10-26 23:37:04 +00:00
Frederic Riss 987fe22789 Sink DwarfUnit::constructImportedEntityDIE into DwarfCompileUnit.
So that it has access to getOrCreateGlobalVariableDIE. If we ever support
decsribing using directive in C++ classes (thus requiring support in type
units), it will certainly use another mechanism anyway.

Differential Revision: http://reviews.llvm.org/D5975

llvm-svn: 220594
2014-10-24 21:31:09 +00:00
David Blaikie ee7df55306 Move DwarfUnit::constructVariableDIE down to DwarfCompileUnit, since it's only needed there.
llvm-svn: 219418
2014-10-09 17:56:36 +00:00
David Blaikie e5feec502d Sink DwarfUnit::addSectionDelta into DwarfCompileUnit, the only place it's needed.
llvm-svn: 219364
2014-10-08 23:30:05 +00:00
David Blaikie 6c0ee4ece3 Sink and coalesce DwarfDebug.cpp::addSectionLabel and DwarfUnit::addSectionLabel down into DwarfCompileUnit::addSectionLabel
llvm-svn: 219351
2014-10-08 22:46:27 +00:00
David Blaikie febfafd13a DebugInfo: Sink constructImportedEntityDIE down into DwarfUnit from DwarfDebug.
It was just calling a bunch of DwarfUnit functions anyway, as can be
seen by the simplification of removing "TheCU" from all the function
calls in the implementation.

llvm-svn: 219103
2014-10-06 05:37:24 +00:00
David Blaikie 37c5231051 Move DwarfCompileUnit from DwarfUnit.h to its own header (DwarfCompileUnit.h)
In preparation for sinking all the subprogram emission code down from
DwarfDebug into DwarfCompileUnit, this will avoid bloating
DwarfUnit.h/cpp greatly and make concerns a bit more clear/isolated.

(sinking this handling down is part of the work to handle emitting
minimal subprograms for -gmlt-like data into the skeleton CU under
fission)

llvm-svn: 219057
2014-10-04 15:49:50 +00:00
Duncan P. N. Exon Smith 176b691d32 Revert "Revert "DI: Fold constant arguments into a single MDString""
This reverts commit r218918, effectively reapplying r218914 after fixing
an Ocaml bindings test and an Asan crash.  The root cause of the latter
was a tightened-up check in `DILexicalBlock::Verify()`, so I'll file a
PR to investigate who requires the loose check (and why).

Original commit message follows.

--

This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

llvm-svn: 219010
2014-10-03 20:01:09 +00:00
Duncan P. N. Exon Smith 786cd049fc Revert "DI: Fold constant arguments into a single MDString"
This reverts commit r218914 while I investigate some bots.

llvm-svn: 218918
2014-10-02 22:15:31 +00:00
Duncan P. N. Exon Smith 571f97bd90 DI: Fold constant arguments into a single MDString
This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

llvm-svn: 218914
2014-10-02 21:56:57 +00:00
Adrian Prantl 87b7eb9d0f Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

Note: I accidentally committed a bogus older version of this patch previously.
llvm-svn: 218787
2014-10-01 18:55:02 +00:00
Adrian Prantl b458dc2eee Revert r218778 while investigating buldbot breakage.
"Move the complex address expression out of DIVariable and into an extra"

llvm-svn: 218782
2014-10-01 18:10:54 +00:00
Adrian Prantl 25a7174e7a Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

llvm-svn: 218778
2014-10-01 17:55:39 +00:00
David Blaikie 32b0f365a2 Implement DW_TAG_subrange_type with DW_AT_count rather than DW_AT_upper_bound
This allows proper disambiguation of unbounded arrays and arrays of zero
bound ("struct foo { int x[]; };" and "struct foo { int x[0]; }"). GCC
instead produces an upper bound of -1 in the latter situation, but count
seems tidier. This way lower_bound is provided if it's not the language
default and count is provided if the count is known, otherwise it's
omitted. Simple.

If someone wants to look at rdar://problem/12566646 and see if this
change is acceptable to that bug/fix, that might be helpful (see the
empty-and-one-elem-array.ll test case which cites that radar).

llvm-svn: 218726
2014-10-01 00:56:55 +00:00
David Blaikie 3a7ce252cc Omit DW_TAG_subprograms for subprograms without inlined subroutines when producing -gmlt data
To reduce the size of -gmlt data, skip the subprograms without any
inlined subroutines. Since we've now got the ability to make these
determinations in the backend (funnily enough - we added the flag so we
wouldn't produce ranges under -gmlt, but with this change we use the
flag, but go back to producing ranges under -gmlt).

Instead, just produce CU ranges to inform the consumer which parts of
the code are described by this CU's line table. Tools could inspect the
line table directly to compute the range, but the CU ranges only seem to
be about 0.5% of object/executable size, so I'm not too worried about
teaching llvm-symbolizer that trick just yet - it's certainly a possible
piece of future work.

Update an llvm-symbolizer test just to demonstrate that this schema is
acceptable there (if it wasn't, the compiler-rt tests would catch this,
but good to have an in-llvm-tree test for llvm-symbolizer's behavior
here)

Building the clang binary with -gmlt with this patch reduces the total
size of object files by 5.1% (5.56% without ranges) without compression
and the executable by 4.37% (4.75% without ranges).

llvm-svn: 218129
2014-09-19 17:03:16 +00:00
Frederic Riss 9ba9efff56 Change DwarfCompileUnit::createGlobalVariable to getOrCreateGlobalVariable.
Summary:
This will allow to request the creation of a forward delacred variable
at is point of use (for imported declarations, this will be
DwarfDebug::constructImportedEntityDIE) rather than having to put the
forward decl in a retention list.

Note that getOrCreateGlobalVariable returns the actual definition DIE when the
routine creates a declaration and a definition DIE. If you agree this is the
right behavior, then I'll have a followup patch that registers the definition
in the DIE map instead of the declaration as it is today (this 'breaks' only
one test, where we test that the imported entity is the declaration). I'm
not sure what's best here, but it's easy enough for a consumer to follow the
DW_AT_specification link to get to the declaration, whereas it takes more
work to find the actual definition from a declaration DIE.

Reviewers: echristo, dblaikie, aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5381

llvm-svn: 218126
2014-09-19 15:12:03 +00:00
David Blaikie 0b9438b1c1 Describe the -gmlt optimization committed in the previous revision.
llvm-svn: 218099
2014-09-19 04:47:46 +00:00
David Blaikie 73b65d236c Omit all the extra static attributes on subprograms in -gmlt
This omission will be done in a fancier manner once we're dealing with
"put gmlt in the skeleton CUs under fission" - it'll have to be
conditional on the kind of CU we're emitting into (skeleton or gmlt).

llvm-svn: 218098
2014-09-19 04:30:36 +00:00
Frederic Riss 0baab0cded Revert part of r218041.
The patch moved some logic around in an attempt to generate potentially more
DW_AT_declaration attributes. The patch was flawed though and it stopped
generating the attribute in some cases.

llvm-svn: 218060
2014-09-18 16:41:04 +00:00
Frederic Riss be26dfb595 Always emit DW_AT_declaration attribute when the variable isn't a definition.
Summary:
This doesn't show up today as we don't emit decalration only variables. This
will be tested when the followup patches implementing import of forward
declared entities lands in clang.

Reviewers: echristo, dblaikie, aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5382

llvm-svn: 218041
2014-09-18 09:38:23 +00:00
David Blaikie ba656e1d7c DebugInfo: Add comment describing the need to disable address pool usage in skeleton units.
Post commit review from Eric Christopher.

llvm-svn: 217842
2014-09-15 22:41:25 +00:00
David Blaikie 6741bb09bb Remove the unused string section symbol parameter from DwarfFile::emitStrings
And since it /looked/ like the DwarfStrSectionSym was unused, I tried
removing it - but then it turned out that DwarfStringPool was
reconstructing the same label (and expecting it to have already been
emitted) and uses that.

So I kept it around, but wanted to pass it in to users - since it seemed
a bit silly for DwarfStringPool to have it passed in and returned but
itself have no use for it. The only two users don't handle strings in
both .dwo and .o files so they only ever need the one symbol - no need
to keep it (and have an unused symbol) in the DwarfStringPool used for
fission/.dwo.

Refactor a bunch of accelerator table usage to remove duplication so I
didn't have to touch 4-5 callers.

llvm-svn: 217628
2014-09-11 21:12:48 +00:00
David Blaikie d0f103775a Sink PrevCU updating into DwarfUnit::addRange to ensure consistency
So that the two operations in DwarfDebug couldn't get separated (because
I accidentally separated them in some work in progress), put them
together. While we're here, move DwarfUnit::addRange to
DwarfCompileUnit, since it's not relevant to type units.

llvm-svn: 217468
2014-09-09 23:13:01 +00:00