Commit Graph

810 Commits

Author SHA1 Message Date
Adrian Prantl 283833d022 Add a testcase for DIExpression(DW_OP_stack_value)
and relax the assertion that prohibited its emission.

This fixes the assertion failure uncovered by r301093.

llvm-svn: 301209
2017-04-24 18:11:38 +00:00
Renato Golin 54c736f833 [DWARF] Move test to x86 directory
llvm-svn: 301176
2017-04-24 12:37:11 +00:00
David Blaikie 5477b97d45 Fix test to handle .rel and .rela sections (& to actually specify the target architecture as X86)
llvm-svn: 301073
2017-04-22 08:17:39 +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
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 ada104888e Don't emit locations that need a DW_OP_stack_value in DWARF 2 & 3.
https://bugs.llvm.org/show_bug.cgi?id=32382

llvm-svn: 300883
2017-04-20 20:42:33 +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 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
Eric Christopher 9ea300f08d If the DIUnit has flags passed on it then have DW_AT_producer be a combination of DICompileUnit::Producer and Flags.
The darwin behavior is unchanged and will continue to use DW_AT_APPLE_flags.

Patch by Zhizhou Yang

llvm-svn: 299038
2017-03-29 23:34:27 +00:00
Adrian Prantl 4994bc0474 Make testcase less nonsensical while still exercising the same code paths.
llvm-svn: 298726
2017-03-24 19:11:31 +00:00
Adrian Prantl f0ffc5233d Fix a bug when emitting debug info for partially constant global variables.
While fixing a malformed testcase, I discovered that the code
exercised by it was wrong, too.

llvm-svn: 298664
2017-03-23 23:35:00 +00:00
Adrian Prantl 3eb1ec9767 Fix testcase on windows.
llvm-svn: 298521
2017-03-22 17:15:03 +00:00
Adrian Prantl 5503077cde Fix PR32298 by adding an early exit to getFrameIndexExprs().
Also add an assertion for the case that there are multiple FI
expressions with a DW_OP_LLVM_fragment; which should violate internal
constraints in DbgVariable.

llvm-svn: 298518
2017-03-22 16:50:16 +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 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
Reid Kleckner f7c0980c10 Elide argument copies during instruction selection
Summary:
Avoids tons of prologue boilerplate when arguments are passed in memory
and left in memory. This can happen in a debug build or in a release
build when an argument alloca is escaped.  This will dramatically affect
the code size of x86 debug builds, because X86 fast isel doesn't handle
arguments passed in memory at all. It only handles the x86_64 case of up
to 6 basic register parameters.

This is implemented by analyzing the entry block before ISel to identify
copy elision candidates. A copy elision candidate is an argument that is
used to fully initialize an alloca before any other possibly escaping
uses of that alloca. If an argument is a copy elision candidate, we set
a flag on the InputArg. If the the target generates loads from a fixed
stack object that matches the size and alignment requirements of the
alloca, the SelectionDAG builder will delete the stack object created
for the alloca and replace it with the fixed stack object. The load is
left behind to satisfy any remaining uses of the argument value. The
store is now dead and is therefore elided. The fixed stack object is
also marked as mutable, as it may now be modified by the user, and it
would be invalid to rematerialize the initial load from it.

Supersedes D28388

Fixes PR26328

Reviewers: chandlerc, MatzeB, qcolombet, inglorion, hans

Subscribers: igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D29668

llvm-svn: 296683
2017-03-01 21:42:00 +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
Adrian Prantl e6c6a945ca Fix windows bots by locking down the target triple on this testcase.
llvm-svn: 295490
2017-02-17 20:02:26 +00:00
Adrian Prantl 67c2442210 Debug Info: Sort frame index expressions before emitting them.
This fixes PR31381, which caused an assertion and/or invalid debug info.

This affects debug variables that have multiple fragments in the MMI
side (i.e.: in the stack frame) table.
rdar://problem/30571676

llvm-svn: 295486
2017-02-17 19:42:32 +00:00
Teresa Johnson 95ed51dcfe Move test to X86 subdirectory for bot failures
Second attempt at fixing bot failures from r295384.

llvm-svn: 295395
2017-02-17 01:23:28 +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
Rafael Espindola 13a79bbfe5 Change how we handle section symbols on ELF.
On ELF every section can have a corresponding section symbol. When in
an assembly file we have

.quad .text

the '.text' refers to that symbol.

The way we used to handle them is to leave .text an undefined symbol
until the very end when the object writer would map them to the
actual section symbol.

The problem with that is that anything before the end would see an
undefined symbol. This could result in bad diagnostics
(test/MC/AArch64/label-arithmetic-diags-elf.s), or incorrect results
when using the asm streamer (est/MC/Mips/expansion-jal-sym-pic.s).

Fixing this will also allow using the section symbol earlier for
setting sh_link of SHF_METADATA sections.

This patch includes a few hacks to avoid changing our behaviour when
handling conflicts between section symbols and other symbols. I
reported pr31850 to track that.

llvm-svn: 293936
2017-02-02 21:26:06 +00:00
Dehao Chen 1fdf3ce9cd Refactor the gmlt tests. (NFC)
llvm-svn: 293852
2017-02-02 01:21:13 +00:00
Paul Robinson 5362216c36 Remove an assertion that doesn't hold when mixing -g and -gmlt through
LTO.  Replace it with a related assertion, ensuring that abstract
variables appear only in abstract scopes.
Part of PR31437.

Differential Revision: http://reviews.llvm.org/D29430

llvm-svn: 293841
2017-02-01 23:51:56 +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
Paul Robinson a380e613f1 Remove an assertion that doesn't hold when mixing -g and -gmlt through
LTO.  Part of PR31437.

Differential Revision: http://reviews.llvm.org/D29310

llvm-svn: 293818
2017-02-01 21:54:50 +00:00
Florian Hahn 5815f6c53c [framelowering] Skip dbg values when getting next/previous instruction.
Summary:
In mergeSPUpdates, debug values need to be ignored when getting the
previous element, otherwise debug data could have an impact on codegen.

In eliminateCallFramePseudoInstr, debug values after the erased element
could have an impact on codegen and should be skipped.

Closes PR31319 (https://llvm.org/bugs/show_bug.cgi?id=31319)

Reviewers: aprantl, MatzeB, mkuper

Subscribers: gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D27688

llvm-svn: 290955
2017-01-04 12:08:35 +00:00
Keno Fischer f7d84ee6ff Reapply "[CodeGen] Fix invalid DWARF info on Win64"
This reapplies rL289013 (reverted in rL289014) with the fixes identified
in D21731. Should hopefully pass the buildbots this time.

llvm-svn: 290809
2017-01-02 03:00:19 +00:00
Sanjoy Das 00d76a5754 [TBAAVerifier] Be stricter around verifying scalar nodes
This fixes the issue exposed in PR31393, where we weren't trying
sufficiently hard to diagnose bad TBAA metadata.

This does reduce the variety in the error messages we print out, but I
think the tradeoff of verifying more, simply and quickly overrules the
need for more helpful error messags here.

llvm-svn: 290713
2016-12-29 15:47:05 +00:00
Adrian Prantl 1eadba1c8c Renumber testcase metadata nodes after r290153.
This patch renumbers the metadata nodes in debug info testcases after
https://reviews.llvm.org/D26769. This is a separate patch because it
causes so much churn. This was implemented with a python script that
pipes the testcases through llvm-as - | llvm-dis - and then goes
through the original and new output side-by side to insert all
comments at a close-enough location.

Differential Revision: https://reviews.llvm.org/D27765

llvm-svn: 290292
2016-12-22 00:45:21 +00:00
Adrian Prantl bceaaa9643 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 290153
2016-12-20 02:09:43 +00:00
Paul Robinson 2dfb688214 Allow "line 0" to be the first explicit debug location in a function.
Feedback on r289468 from Adrian Prantl.

llvm-svn: 290012
2016-12-16 23:54:33 +00:00
Adrian Prantl 73ec065604 Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).

Sorry for the churn!

llvm-svn: 289982
2016-12-16 19:39:01 +00:00
Nico Weber c4d695e25b Speculatively revert r289925, see PR31407
llvm-svn: 289944
2016-12-16 14:02:28 +00:00
Ekaterina Romanova 25da8a9b53 Update .debug_line section version information to match DWARF version.
One more attempt to re-commit the patch r285355, which I had to revert in r285362, because some tests were failing (the reason is because the size of the line_table varied depending on the full file name).

In the past the compiler always emitted .debug_line version 2, though some opcodes from DWARF 3 (e.g. DW_LNS_set_prologue_end, DW_LNS_set_epilogue_begin or DW_LNS_set_isa) and from DWARF 4 could be emitted by the compiler.

This patch changes version information of .debug_line to exactly match the DWARF version. For .debug_line version 4, a new field maximum_operations_per_instruction is emitted.

Differential Revision: https://reviews.llvm.org/D16697

llvm-svn: 289925
2016-12-16 05:10:11 +00:00
Adrian Prantl 74a835cda0 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289920
2016-12-16 04:25:54 +00:00
Adrian Prantl 03c6d31a3b Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289902 while investigating bot berakage.

llvm-svn: 289906
2016-12-16 01:00:30 +00:00
Adrian Prantl ce13935776 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289902
2016-12-16 00:36:43 +00:00
Paul Robinson 8fec3da00c [DWARF] Preserve column number when emitting 'line 0' record
Follow-up to r289256, address a FIXME to avoid resetting the column
number. This reduced .debug_line by 2.6% in a RelWithDebInfo
self-build of clang.

llvm-svn: 289620
2016-12-14 00:27:35 +00:00
Paul Robinson ac7fe5e0c4 Recommit r288212: Emit 'no line' information for interesting 'orphan' instructions.
DWARF specifies that "line 0" really means "no appropriate source
location" in the line table.  By default, use this for branch targets
and some other cases that have no specified source location, to
prevent inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).

Updated patch allows enabling or suppressing this behavior for all
unspecified source locations.

Differential Revision: http://reviews.llvm.org/D24180

llvm-svn: 289468
2016-12-12 20:49:11 +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
Keno Fischer d4ea4c18f1 Revert "[CodeGen] Fix invalid DWARF info on Win64"
Appears to break on build bots. Reverting pending investigation.

llvm-svn: 289014
2016-12-08 01:56:23 +00:00
Keno Fischer 460218fb7d [CodeGen] Fix invalid DWARF info on Win64
The relocations for `DIEEntry::EmitValue` were wrong for Win64
(emitting FK_Data_4 instead of FK_SecRel_4). This corrects that
oversight so that the DWARF data is correct in Win64 COFF files.

Fixes PR15393.

Patch by Jameson Nash <jameson@juliacomputing.com> based on a patch
by David Majnemer.

Differential Revision: https://reviews.llvm.org/D21731

llvm-svn: 289013
2016-12-08 01:40:21 +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
Kostya Serebryany b66cb88c2e revert r288283 as it causes debug info (line numbers) to be lost in instrumented code. also revert r288299 which was a workaround for the problem.
llvm-svn: 288300
2016-12-01 02:06:56 +00:00
Paul Robinson 37a13ddb4b Recommit r288212: Emit 'no line' information for interesting 'orphan' instructions.
The LLDB tests are now ready for this patch.

DWARF specifies that "line 0" really means "no appropriate source
location" in the line table.  Use this for branch targets and some
other cases that have no specified source location, to prevent
inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).

Differential Revision: http://reviews.llvm.org/D24180

llvm-svn: 288283
2016-11-30 22:49:55 +00:00
Paul Robinson 957ba405e8 Revert r288212 due to lldb failure.
llvm-svn: 288216
2016-11-29 23:20:35 +00:00
Paul Robinson 96de8c778b Emit 'no line' information for interesting 'orphan' instructions.
DWARF specifies that "line 0" really means "no appropriate source
location" in the line table.  Use this for branch targets and some
other cases that have no specified source location, to prevent
inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).

Differential Revision: http://reviews.llvm.org/D24180

llvm-svn: 288212
2016-11-29 22:41:16 +00:00
Adrian Prantl 3502f2089c Emit the DW_AT_type for a C++ static member definition
if it is more specific than the one in its DW_AT_specification.

If a static member is an array, the translation unit containing the
member definition may have a more specific type (including its length)
than TUs only seeing the class declaration. This patch adds a
DW_AT_type to the member's DW_TAG_variable in addition to the
DW_AT_specification in these cases. The member type in the
DW_AT_specification still shows the more generic type (without the
length) to avoid defeating type uniquing.

The DWARF standard discourages “duplicating” a DW_AT_type in a member
variable definition but doesn’t explicitly forbid it.  Having the more
specific type (with the array length) available is what allows the
debugger to print the contents of a static array member variable.

https://reviews.llvm.org/D26368
rdar://problem/28706946

llvm-svn: 286302
2016-11-08 22:11:38 +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
Adrian Prantl 56527dc804 Emit DW_OP_piece also if the previous value was a constant.
This fixes a bug in the DWARF backend.

llvm-svn: 285826
2016-11-02 16:12:16 +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
Ekaterina Romanova b7f96d1241 Reverting back r285355: "Update .debug_line section version information to match DWARF version", while I'm investigating a test failure.
llvm-svn: 285362
2016-10-27 23:20:19 +00:00
Ekaterina Romanova 0b82459c6c Update .debug_line section version information to match DWARF version.
In the past the compiler always emitted .debug_line version 2, though some opcodes from DWARF 3 (e.g. DW_LNS_set_prologue_end, DW_LNS_set_epilogue_begin or DW_LNS_set_isa) and from DWARF 4 could be emitted by the compiler. 

This patch changes version information of .debug_line to exactly match the DWARF version. For .debug_line version 4, a new field maximum_operations_per_instruction is emitted. 

Differential Revision: https://reviews.llvm.org/D16697

llvm-svn: 285355
2016-10-27 22:37:25 +00:00
Robert Lougher 660f2f9560 Reapply: "Remove debug location from common tail when tail-merging"
This reapplies revision 285093.  Original commit message:

The branch folding pass tail merges blocks into a common-tail.  However, the
tail retains the debug information from one of the original inputs to the
merge (chosen randomly).  This is a problem for sampled-based PGO, as hits
on the common-tail will be attributed to whichever block was chosen,
irrespective of which path was actually taken to the common-tail.

This patch fixes the issue by nulling the debug location for the common-tail.

Differential Revision: https://reviews.llvm.org/D25742

llvm-svn: 285212
2016-10-26 17:01:47 +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
Robert Lougher 3080d71fc8 revert: "Remove debug location from common tail when tail-merging"
This reverts r285093, as it caused unexpected buildbot failures on
clang-ppc64le-linux, clang-ppc64be-linux, clang-ppc64be-linux-multistage
and clang-ppc64be-linux-lnt.  Failing test ubsan/TestCases/TypeCheck/vptr.cpp.

llvm-svn: 285110
2016-10-25 20:17:58 +00:00
Robert Lougher e32564774c Remove debug location from common tail when tail-merging
The branch folding pass tail merges blocks into a common-tail.  However, the
tail retains the debug information from one of the original inputs to the
merge (chosen randomly).  This is a problem for sampled-based PGO, as hits
on the common-tail will be attributed to whichever block was chosen,
irrespective of which path was actually taken to the common-tail.

This patch fixes the issue by nulling the debug location for the common-tail.

Differential Revision: https://reviews.llvm.org/D25742

llvm-svn: 285093
2016-10-25 18:44:07 +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
Andrea Di Biagio fa90c692db [CodeGenPrepare] When moving a zext near to its associated load, do not retain the original debug location.
CodeGenPrepare knows how to move a zext of a load into the same basic block
where the load lives. The goal is to help ISel match a zero-extending load
instead of two separated instructions.

CGP attempts to move a zext computation even if it lives in a basic block that
does not post-dominate the load's basic block. That means, the hoisted zext may
be speculated. Preserving the zext location would hurt the debugging experience
and the quality of sample pgo.
With this patch, when moving a zext near to its associated load, CGP no longer
propagates the zext's debug location. Instead, CGP conservatively reuses the
same debug location for the load and the zext.

An alternative approach would be to assign an artificial line-0 location to the
zext. However we don't want to over-use the 'line-0' for this particular case
because it would have a size cost in the line-table section for no additional
benefit.

Differential Revision: https://reviews.llvm.org/D25611

llvm-svn: 284377
2016-10-17 11:32:26 +00:00
Reid Kleckner f9dddec21c Improve DEBUG_VALUE assembly comments for spilled bitpieces
Previously we would give up when we saw the bitpiece DWARF expression
and print "[complex expression]" when actually we handled bitpiece
expressions outside the loop.

llvm-svn: 283355
2016-10-05 18:36:02 +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
Peter Collingbourne d4135bbc30 DebugInfo: New metadata representation for global variables.
This patch reverses the edge from DIGlobalVariable to GlobalVariable.
This will allow us to more easily preserve debug info metadata when
manipulating global variables.

Fixes PR30362. A program for upgrading test cases is attached to that
bug.

Differential Revision: http://reviews.llvm.org/D20147

llvm-svn: 281284
2016-09-13 01:12:59 +00:00
David Blaikie a01f295322 DebugInfo: Add flag to CU to disable emission of inline debug info into the skeleton CU
In cases where .dwo/.dwp files are guaranteed to be available, skipping
the extra online (in the .o file) inline info can save a substantial
amount of space - see the original r221306 for more details there.

llvm-svn: 279650
2016-08-24 18:29:49 +00:00
Adrian Prantl ccd546e953 Move tests to the appropriate subdirectory.
llvm-svn: 278948
2016-08-17 16:55:56 +00:00
Wolfgang Pieb 8df58f48dd When the inline spiller rematerializes an instruction, take the debug location from the instruction
that immediately follows the rematerialization point.

Patch by Andrea DiBiagio.

Differential Revision: http://reviews.llvm.org/D23539

llvm-svn: 278822
2016-08-16 17:12:50 +00:00
Reid Kleckner a7b04a589e Don't use %llc_dwarf with -mtriple, they don't combine
llvm-svn: 278758
2016-08-15 22:54:26 +00:00
Wolfgang Pieb 12cd6ddef3 Adding the triple for test comitted with r278703.
llvm-svn: 278755
2016-08-15 22:39:39 +00:00
Wolfgang Pieb dfad9b20c9 Local variables whose address is taken and passed on to a call are described
in debug info using their stack slots instead of as an indirection of param reg + 0
offset. This is done by detecting FrameIndexSDNodes in SelectionDAG and generating
FrameIndexDbgValues for them. This ultimately generates DBG_VALUEs with stack
location operands.

Differential Revision: http://reviews.llvm.org/D23283

llvm-svn: 278703
2016-08-15 18:18:26 +00:00
Quentin Colombet 545e558b82 [MIR] Print on the given output instead of stderr.
Currently the MIR framework prints all its outputs (errors and actual
representation) on stderr.

This patch fixes that by printing the regular output in the output
specified with -o.

Differential Revision: http://reviews.llvm.org/D22251

llvm-svn: 275314
2016-07-13 20:36:03 +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
Adrian Prantl 29ce701a06 Fix the type signature of DwarfExpression::Add.*Constant to support values >32 bits.
This fixes an embarrassing bug when emitting .debug_loc entries for 64-bit+ constants,
which were previously silently truncated to 32 bits.

<rdar://problem/26843232>

llvm-svn: 273736
2016-06-24 21:35:09 +00:00
George Burgess IV 2efbb3f394 Remove hack introduced by r273641.
Hopefully the buildbots have had enough time to pick this up by now.

llvm-svn: 273656
2016-06-24 06:58:15 +00:00
George Burgess IV 43e9ba0e5a Temporary hack to clean a file from buildbots.
Some buildbots are complaining about a .s file under test/ that was
inadvertently created by a test earlier today, and is still hanging
around. I'll undo this change in ~1hr (or whenever the bots are done
getting rid of said file).

llvm-svn: 273641
2016-06-24 02:19:11 +00:00
Nirav Dave 38bb1c15fd Prevent generation of temp file in test from r273585.
llvm-svn: 273588
2016-06-23 18:06:35 +00:00
Nirav Dave bfdb483755 Preserve DebugInfo when replacing values in DAGCombiner
Recommiting after correcting over-eager Debug Value transfer fixing PR28270.

[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.

Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.

This refixes PR9817 which was being incompletely checked in the
testsuite.

Reviewers: jyknight

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D21037

llvm-svn: 273585
2016-06-23 17:52:57 +00:00
Peter Collingbourne 6717803485 Revert r273456, "Preserve DebugInfo when replacing values in DAGCombiner" as it caused pr28270.
llvm-svn: 273518
2016-06-23 00:06:17 +00:00
Nirav Dave 96beb7dee5 Preserve DebugInfo when replacing values in DAGCombiner
Recommiting after fixing over-aggressive assertion

[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.

Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.

This refixes PR9817 which was being incompletely checked in the
testsuite.

Reviewers: jyknight

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D21037

llvm-svn: 273456
2016-06-22 19:03:26 +00:00
Nirav Dave 194cb55f37 Revert "Preserve DebugInfo when replacing values in DAGCombiner"
Reverting due to assertion failure in
lib/CodeGen/SelectionDAG/InstrEmitter.cpp

This reverts commit r272792.

llvm-svn: 272799
2016-06-15 16:08:50 +00:00
Nirav Dave a72e308403 Preserve DebugInfo when replacing values in DAGCombiner
[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.

Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.

This refixes PR9817 which was being incompletely checked in the
testsuite.

Reviewers: jyknight

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D21037

llvm-svn: 272792
2016-06-15 14:50:08 +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
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
Adrian Prantl 723ccd2790 Debug Info: Prevent DW_AT_abstract_origin from being emitted twice
for the same subprogram.

This fixes a bug where DW_AT_abstract_origin is being emitted twice for
the same subprogram if a function is both inlined and emitted in the same
translation unit, by restoring the pre-r266446 behavior.

http://reviews.llvm.org/D20072

llvm-svn: 269103
2016-05-10 19:38:51 +00:00
Wolfgang Pieb a4e71bd11a Moved test case for r268323 to DebugInfo/X86 to unbreak aarch64.
llvm-svn: 268339
2016-05-03 00:22:09 +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 ee04164599 Fixed LIT tests that was broken after change in r268054.
llvm-svn: 268063
2016-04-29 16:54:18 +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
Dehao Chen 1b54fce319 Read discriminators correctly from object file.
Summary:
This is the follow-up patch for http://reviews.llvm.org/D19436
* Update the discriminator reading algorithm to match the assignment algorithm.
* Add test to cover the new algorithm.

Reviewers: dnovillo, echristo, dblaikie

Subscribers: danielcdh, dblaikie, echristo, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19522

llvm-svn: 267945
2016-04-28 22:09:37 +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
Adrian Prantl 93035c8f47 Verifier: Verify that each inlinable callsite of a debug-info-bearing function
in a debug-info-bearing function has a debug location attached to it. Failure to
do so causes an "!dbg attachment points at wrong subprogram for function"
assertion failure when the inliner sets up inline scope info.

rdar://problem/25878916

This reaplies r267320 without changes after fixing an issue in the OpenMP IR
generator in clang.

llvm-svn: 267370
2016-04-24 22:23:13 +00:00
Adrian Prantl da99dced5c Revert "Verifier: Verify that each inlinable callsite of a debug-info-bearing function"
This reverts commit r267320 while investigating an OpenMP buildbot failure.

llvm-svn: 267322
2016-04-24 03:47:37 +00:00
Adrian Prantl 971481db98 Verifier: Verify that each inlinable callsite of a debug-info-bearing function
in a debug-info-bearing function has a debug location attached to it. Failure to
do so causes an "!dbg attachment points at wrong subprogram for function"
assertion failure when the inliner sets up inline scope info.

rdar://problem/25878916

llvm-svn: 267320
2016-04-24 03:23:02 +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
Amjad Aboud a5ba99140c Fixed Dwarf debug info emission to skip DILexicalBlockFile entries.
Before this fix, DILexicalBlockFile entries were skipped only in some cases and were not in other cases.

Differential Revision: http://reviews.llvm.org/D18724

llvm-svn: 267004
2016-04-21 16:58:49 +00:00