Commit Graph

69 Commits

Author SHA1 Message Date
Igor Kudrin def677194c [DebugInfo] Report the format of location and range lists [9/10]
Differential Revision: https://reviews.llvm.org/D80523
2020-06-02 17:55:31 +07:00
Fangrui Song a36ddf0aa9 Migrate function attribute "no-frame-pointer-elim"="false" to "frame-pointer"="none" as cleanups after D56351 2019-12-24 16:27:51 -08:00
Pavel Labath ebe2f56030 DWARFDebugLoclists: add location list "interpretation" logic
Summary:
This patch extracts the logic for computing the "absolute" locations,
which was partially present in the debug_loclists dumper, completes it,
and moves it into a separate function. This makes it possible to later
reuse the same logic for uses other than dumping.

The dumper is changed to reuse the location list interpreter, and its
format is changed somewhat. In "verbose" mode it prints the "raw" value
of a location list, the interpreted location (if available) and the
expression itself. In non-verbose mode it prints only one of the
location forms: it prefers the interpreted form, but falls back to the
"raw" format if interpretation is not possible (for instance, because we
were not given a base address, or the resolution of indirect addresses
failed).

This patch also undos some of the changes made in D69672, namely the
part about making all functions static. The main reason for this is that
I learned that the original approach (dumping only fully resolved
locations) meant that it was impossible to rewrite one of the existing
tests. To make that possible (and make the "inline location" dump work
in more cases), I now reuse the same dumping mechanism as is used for
section-based dumping. As this required having more objects know about
the various location lists classes, it seemed like a good idea to create
an interface abstracting the difference between them.

Therefore, I now create a DWARFLocationTable class, which will serve as
a base class for the location list classes. DWARFDebugLoclists is made
to inherit from that. DWARFDebugLoc will follow.

Another positive effect of this change is that section-based dumping
code will not need to use templates (as originally) envisioned, and that
the argument lists of the dumping functions become shorter.

Reviewers: dblaikie, probinson, JDevlieghere, aprantl, SouraVX

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70081
2019-11-12 10:40:13 +01:00
Pavel Labath e1f8c8a16f DWARFDebugLoclists: Move to a incremental parsing model
Summary:
This patch stems from the discussion D68270 (including some offline
talks). The idea is to provide an "incremental" api for parsing location
lists, which will avoid caching or materializing parsed data. An
additional goal is to provide a high level location list api, which
abstracts the differences between different encoding schemes, and can be
used by users which don't care about those (such as LLDB).

This patch implements the first part. It implements a call-back based
"visitLocationList" api. This function parses a single location list,
calling a user-specified callback for each entry. This is going to be
the base api, which other location list functions (right now, just the
dumping code) are going to be based on.

Future patches will do something similar for the v4 location lists, and
add a mechanism to translate raw entries into concrete address ranges.

Reviewers: dblaikie, probinson, JDevlieghere, aprantl, SouraVX

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69672
2019-11-06 16:25:06 +01:00
David Blaikie f358c3d371 llvm-dwarfdump: Add verbose printing for debug_loclists
llvm-svn: 374582
2019-10-11 19:06:35 +00:00
Jeremy Morse 0ae5498146 [DebugInfo] Remove invalidated locations during LiveDebugValues
LiveDebugValues gives variable locations to blocks, but it should also take
away. There are various circumstances where a variable location is known
until a loop backedge with a different location is detected. In those
circumstances, where there's no agreement on the variable location, it
should be undef / removed, otherwise we end up picking a location that's
valid on some loop iterations but not others.

However, LiveDebugValues doesn't currently do this, see the new testcase
attached. Without this patch, the location of !3 is assumed to be %bar
through the loop. Once it's added to the In-Locations list, it's never
removed, even though the later dbg.value(0... of !3 makes the location
un-knowable.

This patch checks during block-location-joining to see whether any
previously-present locations have been removed in a predecessor. If they
have, the live-ins have changed, and the block needs reprocessing.
Similarly, in transferTerminator, assign rather than |= the Out-Locations
after processing a block, as we may have deleted some previously valid
locations. This will mean that LiveDebugValues performs more propagation
 -- but that's necessary for it being correct.

Differential Revision: https://reviews.llvm.org/D66599

llvm-svn: 369778
2019-08-23 16:33:42 +00:00
Jeremy Morse bcff417292 [DebugInfo] Terminate all location-lists at end of block
This commit reapplies r359426 (which was reverted in r360301 due to
performance problems) and rolls in D61940 to address the performance problem.
I've combined the two to avoid creating a span of slow-performance, and to
ease reverting if more problems crop up.

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

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

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

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

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

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

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

Reviewers: aprantl, dstenb, jmorse

Reviewed By: aprantl, dstenb, jmorse

Subscribers: djtodoro, ivanbaev, asowda

Tags: #debug-info

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

llvm-svn: 362923
2019-06-10 08:41:06 +00:00
Nikola Prica 2d0106a110 [LiveDebugValues] Close range for previous variable's location when adding newly deduced location
When LiveDebugValues deduces new variable's location from spill, restore or
register copy instruction it should close old variable's location. Otherwise
we can have multiple block output locations for same variable. That could lead
to inserting two DBG_VALUEs for same variable to the beginning of the successor
block which results to ignoring of first DBG_VALUE.

Reviewers: aprantl, jmorse, wolfgangp, dstenb

Reviewed By: aprantl

Subscribers: probinson, asowda, ivanbaev, petarj, djtodoro

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D62196

llvm-svn: 362373
2019-06-03 09:48:29 +00:00
Fangrui Song 2f6ef2fc92 DWARF v5: emit DW_AT_addr_base if DW_AT_low_pc references .debug_addr
The condition !AddrPool.empty() is tested before attachRangesOrLowHighPC(), which may add an entry to AddrPool. We emit DW_AT_low_pc (DW_FORM_addrx) but may incorrectly omit DW_AT_addr_base for LineTablesOnly. This can be easily reproduced:

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

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

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

Reviewed By: probinson

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

llvm-svn: 360678
2019-05-14 14:37:26 +00:00
Eric Christopher c93f56d39e Temporarily Revert "[DebugInfo] Terminate more location-list ranges at the end of blocks"
as it was causing significant compile time regressions.

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

llvm-svn: 360301
2019-05-08 23:54:03 +00:00
Jeremy Morse 055aee1d8a [DebugInfo] Terminate more location-list ranges at the end of blocks
This patch fixes PR40795, where constant-valued variable locations can
"leak" into blocks placed at higher addresses. The root of this is that
DbgEntityHistoryCalculator terminates all register variable locations at
the end of each block, but not constant-value variable locations.

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

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

llvm-svn: 359426
2019-04-29 09:13:16 +00:00
David Blaikie 560ff35592 DebugInfo: Avoid using split DWARF when the split unit would be empty.
In ThinLTO many split CUs may be effectively empty because of the lack
of support for cross-unit references in split DWARF.

Using a split unit in those cases is just a waste/overhead - and turned
out to be one contributor to a significant symbolizer performance issue
when global variable debug info was being imported (see r348416 for the
primary fix) due to symbolizers seeing CUs with no ranges, assuming
there might still be addresses covered and walking into the split CU to
see if there are any ranges (when that split CU was in a DWP file, that
meant loading the DWP and its index, the index was extra large because
of all these fractured/empty CUs... and so was very expensive to load).

(the 3rd fix which will follow, is to assume that a CU with no ranges is
empty rather than merely missing its CU level range data - and to not
walk into its DIEs (split or otherwise) in search of address information
that is generally not present)

llvm-svn: 349207
2018-12-14 22:44:46 +00:00
David Blaikie c4af8bf29f DebugInfo: Use address pool forms in debug_rnglists
Save no relocations by reusing addresses from the address pool.

llvm-svn: 344836
2018-10-20 07:36:39 +00:00
David Blaikie 161dd3c186 DebugInfo: Use debug_addr for non-dwo addresses in DWARF 5
Putting addresses in the address pool, even with non-fission, can reduce
relocations - reusing the addresses from debug_info and debug_rnglists
(the latter coming soon)

llvm-svn: 344834
2018-10-20 06:02:15 +00:00
Matthias Braun 81578e9f77 X86, AArch64, ARM: Do not attach debug location to spill/reload instructions
This rebases and recommits r343520. hwasan should be fixed now and this
shouldn't break the tests anymore.

Spill/reload instructions are artificially generated by the compiler and
have no relation to the original source code. So the best thing to do is
not attach any debug location to them (instead of just taking the next
debug location we find on following instructions).

Differential Revision: https://reviews.llvm.org/D52125

llvm-svn: 343895
2018-10-05 22:00:13 +00:00
Matt Morehouse 4b1ec17fb0 Revert "X86, AArch64, ARM: Do not attach debug location to spill/reload instructions"
This reverts r343520 due to breakage of HWASan tests on Android.

llvm-svn: 343616
2018-10-02 18:35:44 +00:00
Matthias Braun 3e081703c3 X86, AArch64, ARM: Do not attach debug location to spill/reload instructions
Spill/reload instructions are artificially generated by the compiler and
have no relation to the original source code. So the best thing to do is
not attach any debug location to them (instead of just taking the next
debug location we find on following instructions).

Differential Revision: https://reviews.llvm.org/D52125

llvm-svn: 343520
2018-10-01 18:56:39 +00:00
Wolfgang Pieb 439801ba1d [DWARF v5] Refactor range lists dumping by using a more generic way of handling tables of lists.
The intent is to use it for location list tables as well. Change is almost NFC with the exception
of the spelling of some strings used during dumping (all lowercase now).

Reviewer: JDevlieghere

Differential Revision: https://reviews.llvm.org/D49500

llvm-svn: 337763
2018-07-23 22:37:17 +00:00
Wolfgang Pieb fcf3810cf7 [DWARF v5] Generate range list tables into the .debug_rnglists section. No support for split DWARF
and no use of DW_FORM_rnglistx with the DW_AT_ranges attribute.

Reviewer: aprantl

Differential Revision: https://reviews.llvm.org/D49214

llvm-svn: 336927
2018-07-12 18:18:21 +00:00
Shiva Chen 2c864551df [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841
2018-05-09 02:40:45 +00:00
Sander de Smalen a86f3cfb49 Revert "[DebugInfo][FastISel] Fix dropping dbg.value()"
This patch reverts r325440 and r325438 because it triggers an
assertion in SelectionDAGBuilder.cpp. Also having debug enabled
may unintentionally affect code-gen. The patch is reverted until
we find a better solution.

llvm-svn: 325825
2018-02-22 19:53:59 +00:00
Sander de Smalen 47952b0c03 [DebugInfo][FastISel] Fix dropping dbg.value()
Summary:
https://llvm.org/PR36263 shows that when compiling at -O0 a dbg.value()
instruction (that remains from an original dbg.declare()) is dropped
by FastISel. Since FastISel selects instructions by iterating a basic
block backwards, it drops the dbg.value if one of its operands is not
yet instantiated by a previously selected instruction.

Instead of calling 'lookUpRegForValue()' we can call 'getRegForValue()'
instead that will insert a placeholder for the operand to be filled in
when continuing the instruction selection.

Reviewers: aprantl, dblaikie, probinson

Reviewed By: aprantl

Subscribers: llvm-commits, dstenb, JDevlieghere

Differential Revision: https://reviews.llvm.org/D43386

llvm-svn: 325438
2018-02-17 16:42:54 +00:00
Adrian Prantl 3ae35eb56b llvm-dwarfdump: automatically dump both regular and .dwo variant of sections
Since users typically don't really care about the .dwo / non.dwo
distinction, this patch makes it so dwarfdump --debug-<info,...> dumps
.debug_info and (if available) also .debug_info.dwo. This simplifies
the command line interface (I've removed all dwo-specific dump
options) and makes the tool friendlier to use.

Differential Revision: https://reviews.llvm.org/D37771

llvm-svn: 313207
2017-09-13 22:09:01 +00:00
Adrian Prantl 16aa4cf7ef llvm-dwarfdump: Make -brief the default and add a -verbose option instead.
Differential Revision: https://reviews.llvm.org/D37717

llvm-svn: 312972
2017-09-11 23:05:20 +00:00
Reid Kleckner a058736c9c [dwarfdump] Pretty print location expressions and location lists
Summary:
Based on Fred's patch here: https://reviews.llvm.org/D6771

I can't seem to commandeer the old review, so I'm creating a new one.

With that change the locations exrpessions are pretty printed inline in the
DIE tree. The output looks like this for debug_loc entries:

    DW_AT_location [DW_FORM_data4]        (0x00000000
       0x0000000000000001 - 0x000000000000000b: DW_OP_consts +3
       0x000000000000000b - 0x0000000000000012: DW_OP_consts +7
       0x0000000000000012 - 0x000000000000001b: DW_OP_reg0 RAX, DW_OP_piece 0x4
       0x000000000000001b - 0x0000000000000024: DW_OP_breg5 RDI+0)

And like this for debug_loc.dwo entries:
    DW_AT_location [DW_FORM_sec_offset]   (0x00000000
      Addr idx 2 (w/ length 190): DW_OP_consts +0, DW_OP_stack_value
      Addr idx 3 (w/ length 23): DW_OP_reg0 RAX, DW_OP_piece 0x4)

Simple locations without ranges are printed inline:

   DW_AT_location [DW_FORM_block1]       (DW_OP_reg4 RSI, DW_OP_piece 0x4, DW_OP_bit_piece 0x20 0x0)

The debug_loc(.dwo) dumping in changed accordingly to factor the code.

Reviewers: dblaikie, aprantl, friss

Subscribers: mgorny, javed.absar, hiraditya, llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D37123

llvm-svn: 312042
2017-08-29 21:41:21 +00:00
Adrian Prantl abe04759a6 Remove the obsolete offset parameter from @llvm.dbg.value
There is no situation where this rarely-used argument cannot be
substituted with a DIExpression and removing it allows us to simplify
the DWARF backend. Note that this patch does not yet remove any of
the newly dead code.

rdar://problem/33580047
Differential Revision: https://reviews.llvm.org/D35951

llvm-svn: 309426
2017-07-28 20:21:02 +00:00
David Blaikie 96b1ed50e8 Move Split DWARF handling to an MC option/command line argument rather than using metadata
Since Split DWARF needs to name the actual .dwo file that is generated,
it can't be known at the time the llvm::Module is produced as it may be
merged with other Modules before the object is generated and that object
may be generated with any name.

By passing the Split DWARF file name when LLVM is producing object code
the .dwo file name in the object file can match correctly.

The support for Split DWARF for implicit modules remains the same -
using metadata to store the dwo name and dwo id so that potentially
multiple skeleton CUs referring to different dwo files can be generated
from one llvm::Module.

llvm-svn: 301062
2017-04-21 23:35:26 +00:00
Adrian Prantl 981f03e6a2 PR32288: More efficient encoding for DWARF expr subregister access.
Citing http://bugs.llvm.org/show_bug.cgi?id=32288

  The DWARF generated by LLVM includes this location:

  0x55 0x93 0x04 DW_OP_reg5 DW_OP_piece(4) When GCC's DWARF is simply
  0x55 (DW_OP_reg5) without the DW_OP_piece. I believe it's reasonable
  to assume the DWARF consumer knows which part of a register
  logically holds the value (low bytes, high bytes, how many bytes,
  etc) for a primitive value like an integer.

This patch gets rid of the redundant DW_OP_piece when a subregister is
at offset 0. It also adds previously missing subregister masking when
a subregister is followed by another operation.

(This reapplies r297960 with two additional testcase updates).

rdar://problem/31069390
https://reviews.llvm.org/D31010

llvm-svn: 297965
2017-03-16 17:14:56 +00:00
Adrian Prantl c5b3351750 Revert "PR32288: More efficient encoding for DWARF expr subregister access."
This reverts commit 2bf453116889a576956892ea9683db4fcd96e30e while investigating buildbot breakage.

llvm-svn: 297962
2017-03-16 16:38:22 +00:00
Adrian Prantl 8508e87998 PR32288: More efficient encoding for DWARF expr subregister access.
Citing http://bugs.llvm.org/show_bug.cgi?id=32288

  The DWARF generated by LLVM includes this location:

  0x55 0x93 0x04 DW_OP_reg5 DW_OP_piece(4) When GCC's DWARF is simply
  0x55 (DW_OP_reg5) without the DW_OP_piece. I believe it's reasonable
  to assume the DWARF consumer knows which part of a register
  logically holds the value (low bytes, high bytes, how many bytes,
  etc) for a primitive value like an integer.

This patch gets rid of the redundant DW_OP_piece when a subregister is
at offset 0. It also adds previously missing subregister masking when
a subregister is followed by another operation.

rdar://problem/31069390
https://reviews.llvm.org/D31010

llvm-svn: 297960
2017-03-16 16:34:14 +00:00
Adrian Prantl 7f5866c227 Teach LiveDebugValues about lexical scopes.
This addresses PR26055 LiveDebugValues is very slow.

Contrary to the old LiveDebugVariables pass LiveDebugValues currently
doesn't look at the lexical scopes before inserting a DBG_VALUE
intrinsic. This means that we often propagate DBG_VALUEs much further
down than necessary. This is especially noticeable in large C++
functions with many inlined method calls that all use the same
"this"-pointer.

For example, in the following code it makes no sense to propagate the
inlined variable a from the first inlined call to f() into any of the
subsequent basic blocks, because the variable will always be out of
scope:

void sink(int a);
void __attribute((always_inline)) f(int a) { sink(a); }
void foo(int i) {
   f(i);
   if (i)
     f(i);
   f(i);
}

This patch reuses the LexicalScopes infrastructure we have for
LiveDebugVariables to take this into account.

The effect on compile time and memory consumption is quite noticeable:
I tested a benchmark that is a large C++ source with an enormous
amount of inlined "this"-pointers that would previously eat >24GiB
(most of them for DBG_VALUE intrinsics) and whose compile time was
dominated by LiveDebugValues. With this patch applied the memory
consumption is 1GiB and 1.7% of the time is spent in LiveDebugValues.

https://reviews.llvm.org/D24994
Thanks to Daniel Berlin and Keith Walker for reviewing!

llvm-svn: 282611
2016-09-28 17:51:14 +00:00
Adrian Prantl 75819aedf6 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00
Adrian Prantl b8089516a5 testcase gardening: update the emissionKind enum to the new syntax. (NFC)
llvm-svn: 265081
2016-04-01 00:16:49 +00:00
Adrian Prantl b939a25707 Move the DebugEmissionKind enum from DIBuilder into DICompileUnit.
This mostly cosmetic patch moves the DebugEmissionKind enum from DIBuilder
into DICompileUnit. DIBuilder is not the right place for this enum to live
in — a metadata consumer should not have to include DIBuilder.h.
I also added a Verifier check that checks that the emission kind of a
DICompileUnit is actually legal.

http://reviews.llvm.org/D18612
<rdar://problem/25427165>

llvm-svn: 265077
2016-03-31 23:56:58 +00:00
Vikram TV 859ad29b52 Recommit LiveDebugValues pass after fixing a couple of minor issues.
llvm-svn: 255759
2015-12-16 11:09:48 +00:00
Mehdi Amini ceca971576 Revert "Implement a new pass - LiveDebugValues - to compute the set of live DEBUG_VALUEs at each basic block and insert them. Reviewed and accepted at: http://reviews.llvm.org/D11933"
This reverts commit r255096.

Break the bots: http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_check/16378/

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 255101
2015-12-09 08:17:42 +00:00
Vikram TV 0876d2d5cf Implement a new pass - LiveDebugValues - to compute the set of live DEBUG_VALUEs at each basic block and insert them. Reviewed and accepted at: http://reviews.llvm.org/D11933
llvm-svn: 255096
2015-12-09 05:49:14 +00:00
Peter Collingbourne d4bff30370 DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.

For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.

This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.

Since this is an IR change, a bitcode upgrade has been provided.

Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.

Differential Revision: http://reviews.llvm.org/D14265

llvm-svn: 252219
2015-11-05 22:03:56 +00:00
Duncan P. N. Exon Smith 814b8e91c7 DI: Require subprogram definitions to be distinct
As a follow-up to r246098, require `DISubprogram` definitions
(`isDefinition: true`) to be 'distinct'.  Specifically, add an assembler
check, a verifier check, and bitcode upgrading logic to combat testcase
bitrot after the `DIBuilder` change.

While working on the testcases, I realized that
test/Linker/subprogram-linkonce-weak-odr.ll isn't relevant anymore.  Its
purpose was to check for a corner case in PR22792 where two subprogram
definitions match exactly and share the same metadata node.  The new
verifier check, requiring that subprogram definitions are 'distinct',
precludes that possibility.

I updated almost all the IR with the following script:

    git grep -l -E -e '= !DISubprogram\(.* isDefinition: true' |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's/= \(!DISubprogram(.*, isDefinition: true\)/= distinct \1/'

Likely some variant of would work for out-of-tree testcases.

llvm-svn: 246327
2015-08-28 20:26:49 +00:00
Duncan P. N. Exon Smith 55ca964e94 DI: Disallow uniquable DICompileUnits
Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode.  This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.

Almost all the testcases were updated with this script:

    git grep -e '= !DICompileUnit' -l -- test |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'

I imagine something similar should work for out-of-tree testcases.

llvm-svn: 243885
2015-08-03 17:26:41 +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
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
Rafael Espindola 933f51af54 Use the i8 immediate cmp instructions when possible.
llvm-svn: 232378
2015-03-16 14:25:08 +00:00
Rafael Espindola e7ce9ec398 Use add32ri8 and friends on fast isel.
This fixes pr22854.

The core issue on the bug is that there are multiple instructions that
print the same in assembly. In fact, there doesn't seem to be any
syntax for specifying that a constant that fits in 8 bits should use a 32 bit
immediate.

The attached patch changes fast isel to consider i16immSExt8,
i32immSExt8, and i64immSExt8. They were disabled because fastisel didn’t know
to call the predicate back in the day.

llvm-svn: 232223
2015-03-13 22:18:18 +00:00
Duncan P. N. Exon Smith e274180f0e DebugInfo: Move new hierarchy into place
Move the specialized metadata nodes for the new debug info hierarchy
into place, finishing off PR22464.  I've done bootstraps (and all that)
and I'm confident this commit is NFC as far as DWARF output is
concerned.  Let me know if I'm wrong :).

The code changes are fairly mechanical:

  - Bumped the "Debug Info Version".
  - `DIBuilder` now creates the appropriate subclass of `MDNode`.
  - Subclasses of DIDescriptor now expect to hold their "MD"
    counterparts (e.g., `DIBasicType` expects `MDBasicType`).
  - Deleted a ton of dead code in `AsmWriter.cpp` and `DebugInfo.cpp`
    for printing comments.
  - Big update to LangRef to describe the nodes in the new hierarchy.
    Feel free to make it better.

Testcase changes are enormous.  There's an accompanying clang commit on
its way.

If you have out-of-tree debug info testcases, I just broke your build.

  - `upgrade-specialized-nodes.sh` is attached to PR22564.  I used it to
    update all the IR testcases.
  - Unfortunately I failed to find way to script the updates to CHECK
    lines, so I updated all of these by hand.  This was fairly painful,
    since the old CHECKs are difficult to reason about.  That's one of
    the benefits of the new hierarchy.

This work isn't quite finished, BTW.  The `DIDescriptor` subclasses are
almost empty wrappers, but not quite: they still have loose casting
checks (see the `RETURN_FROM_RAW()` macro).  Once they're completely
gutted, I'll rename the "MD" classes to "DI" and kill the wrappers.  I
also expect to make a few schema changes now that it's easier to reason
about everything.

llvm-svn: 231082
2015-03-03 17:24:31 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
Duncan P. N. Exon Smith 9885469922 IR: Move MDLocation into place
This commit moves `MDLocation`, finishing off PR21433.  There's an
accompanying clang commit for frontend testcases.  I'll attach the
testcase upgrade script I used to PR21433 to help out-of-tree
frontends/backends.

This changes the schema for `DebugLoc` and `DILocation` from:

    !{i32 3, i32 7, !7, !8}

to:

    !MDLocation(line: 3, column: 7, scope: !7, inlinedAt: !8)

Note that empty fields (line/column: 0 and inlinedAt: null) don't get
printed by the assembly writer.

llvm-svn: 226048
2015-01-14 22:27:36 +00:00
Duncan P. N. Exon Smith be7ea19b58 IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

llvm-svn: 224257
2014-12-15 19:07:53 +00:00
Frederic Riss e939b43aa4 [dwarfdump] Dump DW_AT_ranges values inline in the debug_info dump.
The output looks like that:
                      DW_AT_ranges [FORM_data4]    (0x00000000
                         [0x00000001000024a0 - 0x00000001000024c2)
                         [0x0000000100002505 - 0x000000010000268b))

Differential Revision: http://reviews.llvm.org/D5712

llvm-svn: 220466
2014-10-23 04:08:34 +00:00