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Commit Graph

2824 Commits

Author SHA1 Message Date
Awanish Pandey
385e6ab82f [DWARF5][DebugInfo]: Added support for DebugInfo generation for auto return type for C++ member functions.
Summary:
This patch will provide support for auto return type for the C++ member
functions. Before this return type of the member function is deduced and
stored in the DIE.
This patch includes llvm side implementation of this feature.

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

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

Reviewed by: dblaikie

Differential Revision: https://reviews.llvm.org/D70524
2020-01-13 12:26:13 +05:30
Matt Arsenault
2346ede1ad llc: Change behavior of -mcpu with existing attribute
Don't overwrite existing target-cpu attributes.

I've often found the replacement behavior annoying, and this is
inconsistent with how the fast math command line flags interact with
the function attributes.

Does not yet change target-features, since I think that should behave
as a concatenation.
2020-01-07 10:10:25 -05:00
David Blaikie
4e9ff212ca Revert "DebugInfo: Fix rangesBaseAddress DICompileUnit bitcode serialization/deserialization"
Seeing some curious CFI failures internally - which makes little sense
to me, as I don't think anyone is using this flag (even us,
internally)... so sounds like a bug in my code somewhere (possibly a
latent one that propagating this flag exposed, not sure). Reverting
while I investigate.

This reverts commit c51b45e32ef7f35c11891f60871aa9c2c04cd991.
2019-12-30 22:33:35 -08:00
David Blaikie
84060ad0e7 DebugInfo: Fix rangesBaseAddress DICompileUnit bitcode serialization/deserialization
Follow-up to r346788 review feedback from Adrian Prantl.
2019-12-27 17:26:14 -08:00
Kristina Bessonova
678c15be2e [DebugInfo][SelectionDAG] Change order while transferring SDDbgValue to another node
SelectionDAG::transferDbgValues() can 'reattach' SDDbgValue from one to
another node, but doesn't change its source order. If the destination node has
the order greater than the SDDbgValue, there are two possible issues
revealed later:

* If debug info is attached to an instruction that is the first definition
of a register, this ends up with a def-after-use and the debug info
gets 'undef' later.

* If MIR has another definition of a register above the debug info,
the debug info may represent a source variable incorrectly because
it appears (significantly) before an instruction corresponded
to this debug info.

So, the patch changes the order of an SDDbgValue when it is moved
to a node with greater order.

Reviewers: dblaikie, jmorse, aprantl

Reviewed By: aprantl

Subscribers: aprantl, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71175
2019-12-26 21:01:59 +03:00
Fangrui Song
2d0a36fd96 Migrate function attribute "no-frame-pointer-elim"="false" to "frame-pointer"="none" as cleanups after D56351 2019-12-24 16:27:51 -08:00
Fangrui Song
148dd94d20 Migrate function attribute "no-frame-pointer-elim-non-leaf" to "frame-pointer"="non-leaf" as cleanups after D56351 2019-12-24 16:05:15 -08:00
Fangrui Song
d9c5df08b1 Migrate function attribute "no-frame-pointer-elim" to "frame-pointer"="all" as cleanups after D56351 2019-12-24 15:57:33 -08:00
David Blaikie
c99ccc8b9e DebugInfo: Correct the form of DW_AT_macro_info in .dwo files (sec_offset, rather than data4) 2019-12-24 01:23:21 -08:00
Sourabh Singh Tomar
55e59a9eba [DebugInfo] Fix v4 macinfo for dwo files.
Dwo files must contain have DW_AT_macro_info attribute, when macro information is emitted. Adjusted the test case
for the same.
2019-12-24 12:50:34 +05:30
Igor Kudrin
39128b297e [DWARF] Check that all fields of a Unit Header are read.
Tests "dwarfdump-rnglists-dwarf64.s" and "dwarfdump-rnglists.s" were
malformed because they had missing required DWO ID fields in split
compilation unit headers. The patch fixes the tests and checks
the reading of a unit header more thoroughly.

Differential Revision: https://reviews.llvm.org/D71704
2019-12-24 09:38:20 +07:00
Vedant Kumar
65fb265c86 [DWARF] Defer creating declaration DIEs until we prepare call site info
It isn't necessary to create DIEs for all of the declaration subprograms
in a CU's retainedTypes list. We can defer creating these subprograms
until we need to prepare a call site tag that refers to one.

This cleanup was mentioned in passing in D70350.
2019-12-20 15:26:31 -08:00
Vedant Kumar
a496d0518f Reland: [DWARF] Allow cross-CU references of subprogram definitions
This allows a call site tag in CU A to reference a callee DIE in CU B
without resorting to creating an incomplete duplicate DIE for the callee
inside of CU A.

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

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

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

Update:

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

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

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

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

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

Differential Revision: https://reviews.llvm.org/D70350
2019-12-20 15:26:31 -08:00
Yury Delendik
6939b086bb [WebAssembly] Use TargetIndex operands in DbgValue to track WebAssembly operands locations
Extends DWARF expression language to express locals/globals locations. (via
target-index operands atm) (possible variants are: non-virtual registers
or address spaces)

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

Reviewed By: aprantl, dschuff

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D52634
2019-12-20 14:39:05 -08:00
Adrian Prantl
4dc53df55f Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot
This is a purely cosmetic change that is NFC in terms of the binary
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot
since the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any
useful information otherwise.

This attribute only appears in Clang module debug info.

Differential Revision: https://reviews.llvm.org/D71722
2019-12-20 13:11:17 -08:00
Evgenii Stepanov
809f567590 llvm-symbolizer: support DW_FORM_loclistx locations.
Summary:
With -gdwarf-5 local variable locations are emitted as DW_FORM_loclistx
form instead of the regular DW_FORM_sec_offset. Teach
DWARFDie::getLocations to understand the new format and use it in
llvm-symbolizer "FRAME" command.

Reviewers: pcc, jdoerfert

Subscribers: srhines, aprantl, hiraditya, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70756
2019-12-20 10:36:14 -08:00
Tom Weaver
6bf5a34797 [OPT-DBG] Teach DbgEntityHistoryCalculator about meta-instructions.
The calculator was considering instructions such as KILLs as clobbers
of a physical address. This is wrong as meta instructions such as KILLs
produce no output in the final program and thus don't clobber or change
any physical location's value. As a result they're safe to ignore whilst
calculating location list ranges.

reviewers: aprantl, vsk

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

fixes: https://bugs.llvm.org/show_bug.cgi?id=38753
2019-12-20 14:03:34 +00:00
David Blaikie
e14a38c80f DebugInfo: Fix test fallout from aaa5a5e7ff1aee632aae75311e7c044f710dd0a0 2019-12-18 19:00:40 -08:00
David Blaikie
b90ca11f23 DebugInfo: Include DW_AT_base_addr even in gmlt with no inline functions
Since the address pool doesn't get populated in this case (due to the
lack of inlining, no child DIEs are added to the CU - so no addresses
are needed for the DIEs themselves) until the range list is emitted - at
the time the attributes are added to the CU, the address pool is empty.
So check whether the address pool will be used for the range lists & add
an addr_base if that's the case.
2019-12-18 17:14:28 -08:00
stozer
52b363d22e Reapply: [DebugInfo] Correctly handle salvaged casts and split fragments at ISel
This reverts commit 1f3dd83cc1f2b8f72b9d59e2b4221b12fb7f9a95, reapplying
commit bb1b0bc4e57428ce364d3d6c075ff03cb8973462.

The original commit failed on some builds seemingly due to the use of a
bracketed constructor with an std::array, i.e. `std::array<> arr({...})`.
2019-12-18 16:26:42 +00:00
stozer
3ed183d768 Revert "[DebugInfo] Correctly handle salvaged casts and split fragments at ISel"
Reverted due to build failure on windows bots.

This reverts commit bb1b0bc4e57428ce364d3d6c075ff03cb8973462.
2019-12-18 11:46:10 +00:00
stozer
1187611a04 [DebugInfo] Correctly handle salvaged casts and split fragments at ISel
Previously, LLVM had no functional way of performing casts inside of a
DIExpression(), which made salvaging cast instructions other than Noop
casts impossible. This patch enables the salvaging of casts by using the
DW_OP_LLVM_convert operator for SExt and Trunc instructions.

There is another issue which is exposed by this fix, in which fragment
DIExpressions (which are preserved more readily by this patch) for
values that must be split across registers in ISel trigger an assertion,
as the 'split' fragments extend beyond the bounds of the fragment
DIExpression causing an error. This patch also fixes this issue by
checking the fragment status of DIExpressions which are to be split, and
dropping fragments that are invalid.
2019-12-18 11:09:18 +00:00
Sourabh Singh Tomar
db77ea2438 Recommit "[DebugInfo] Refactored macro related generation,
added a test case for macinfo.dwo emission."

This was reverted in caa412090666c10f854322cdc701c1cbf8ed726e,
since it was causing an assertion failure on Windows bots.
This revision is revised to fix that.

Original commit message -

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

Reviewers: dblaikie, aprantl, jini.susan.george

Tags: #debug-info #llvm

Differential Revision: https://reviews.llvm.org/D71008
2019-12-18 02:12:59 +05:30
Raphael Isemann
9670741b0c [ObjC][DWARF] Emit DW_AT_APPLE_objc_direct for methods marked as __attribute__((objc_direct))
Summary:
With DWARF5 it is no longer possible to distinguish normal methods and methods with `__attribute__((objc_direct))` by just looking at the debug information
as they are both now children of the of the DW_TAG_structure_type that defines them (before only the `__attribute__((objc_direct))` methods were children).

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

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

Reviewers: aprantl, SouraVX

Reviewed By: aprantl

Subscribers: hiraditya, cfe-commits, llvm-commits

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

Differential Revision: https://reviews.llvm.org/D71201
2019-12-17 09:40:36 +01:00
Bjorn Pettersson
4d4e52ff5c [BasicBlockUtils] Fix dbg.value elimination problem in MergeBlockIntoPredecessor
Summary:
In commit d60f34c20a2f31335c8d5626e (llvm-svn 317128,
PR35113) MergeBlockIntoPredecessor was changed into
discarding some dbg.value intrinsics referring to
PHI values, post-splice due to loop rotation.

That elimination of dbg.value intrinsics did not
consider which dbg.value to keep depending on the
context (e.g. if the variable is changing its value
several times inside the basic block).

In the past that hasn't been such a big problem since
CodeGenPrepare::placeDbgValues has moved the dbg.value
to be next to the PHI node anyway. But after commit
00e238896cd8ad3a7d7 CodeGenPrepare isn't doing that
any longer, so we need to be more careful when avoiding
duplicate dbg.value intrinsics in MergeBlockIntoPredecessor.

This patch replaces the code that tried to avoid duplicate
dbg.values by using the RemoveRedundantDbgInstrs helper.

Reviewers: aprantl, jmorse, vsk

Reviewed By: aprantl, vsk

Subscribers: jholewinski, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71480
2019-12-16 11:41:21 +01:00
Fangrui Song
0973858503 [AArch64] Save FP for leaf functions when disabling frame pointer elimination
The change allows clang -mno-omit-leaf-frame-pointer to disable frame
pointer elimination. This behavior matches X86 and Mips, and also GCC
AArch64.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D71168
2019-12-13 18:48:58 -08:00
David Stenberg
fa448e3ce2 [LiveDebugValues] Omit entry values for DBG_VALUEs with pre-existing expressions
Summary:
This is a quickfix for PR44275. An assertion that checks that the
DIExpression is valid failed due to attempting to create an entry value
for an indirect parameter. This started appearing after D69028, as the
indirect parameter started being represented using an DW_OP_deref,
rather than with the DBG_VALUE's second operand, meaning that the
isIndirectDebugValue() check in LiveDebugValues did not exclude such
parameters. A DIExpression that has an entry value operation can
currently not have any other operation, leading to the failed isValid()
check.

This patch simply makes us stop considering emitting entry values
for such parameters. To support such cases I think we at least need
to do the following changes:

 * In DIExpression::isValid(): Remove the limitation that a
   DW_OP_LLVM_entry_value operation can be the only operation in a
   DIExpression.

 * In LiveDebugValues::emitEntryValues(): Create an entry value of size
   1, so that it only wraps the register operand, and not the whole
   pre-existing expression (the DW_OP_deref).

 * In LiveDebugValues::removeEntryValue(): Check that the new debug
   value has the same debug expression as the original, rather than
   checking that the debug expression is empty.

 * In DwarfExpression::addMachineRegExpression(): Modify the logic so
   that a DW_OP_reg* expression is emitted for the entry value.
   That is how GCC emits entry values for indirect parameters. That will
   currently not happen to due the DW_OP_deref causing the
   !HasComplexExpression to fail. The LocationKind needs to be changed
   also, rather than always emitting a DW_OP_stack_value for entry values.

There are probably more things I have missed, but that could hopefully
be a good starting point for emitting such entry values.

Reviewers: djtodoro, aprantl, jmorse, vsk

Reviewed By: aprantl, vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D71416
2019-12-13 10:49:46 +01:00
Alexey Lapshin
75c11c7169 [DWARF5][DWARFVerifier] Check that Skeleton compilation unit does not have children.
That patch adds checking into DWARFVerifier that the Skeleton
compilation unit does not have children.

Differential Revision: https://reviews.llvm.org/D71244
2019-12-12 10:59:10 +03:00
Vedant Kumar
0c775a21ee Revert "[DWARF] Allow cross-CU references of subprogram definitions"
This reverts commit 30038da15b18ac4e34b9ea7a648382ae481e4770. It causes
the stage2 thinLTO bot to fail with:

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

rdar://57840415
2019-12-11 15:55:48 -08:00
Nico Weber
539c3f0528 Revert "[DebugInfo] Refactored macro related generation, added a test case for macinfo.dwo emission."
This reverts commit 307f60a1a3ff04313a75e2fc11bc14df4fc2ffb8.

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

Command Output (stdout):
--
$ ":" "RUN: at line 1"
$ "c:\src\llvm-project\out\gn\bin\llc.exe" "-mtriple=x86_64-pc-windows-gnu" "-O0" "-split-dwarf-file=foo.dwo" "-filetype=obj"
Assertion failed: Section && "Cannot switch to a null section!", file ../../llvm/lib/MC/MCStreamer.cpp, line 1103
Stack dump:
0.	Program arguments: c:\src\llvm-project\out\gn\bin\llc.exe -mtriple=x86_64-pc-windows-gnu -O0 -split-dwarf-file=foo.dwo -filetype=obj
2019-12-10 21:32:30 -05:00
Vedant Kumar
83067278fa [DWARF] Allow cross-CU references of subprogram definitions
This allows a call site tag in CU A to reference a callee DIE in CU B
without resorting to creating an incomplete duplicate DIE for the callee
inside of CU A.

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

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

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

rdar://46577651

Differential Revision: https://reviews.llvm.org/D70350
2019-12-10 14:00:57 -08:00
Sourabh Singh Tomar
54ce5c0514 [DebugInfo] Refactored macro related generation, added a test case for macinfo.dwo emission.
Reviewers: dblaikie, aprantl, jini.susan.george

Tags: #debug-info #llvm

Differential Revision: https://reviews.llvm.org/D71008
2019-12-11 02:19:27 +05:30
Sourabh Singh Tomar
61a9c172e2 Recommit "[DWARF5] Start emitting DW_AT_dwo_name when -gdwarf-5 is specified."
Reviewers: dblaikie, aprantl, probinson

Tags: #debug-info #llvm

Differential Revision: https://reviews.llvm.org/D71185
2019-12-11 01:24:50 +05:30
Sourabh Singh Tomar
b6ee09cff1 Revert "[DWARF5] Start emitting DW_AT_dwo_name when -gdwarf-5 is specified."
This reverts commit 6ef01588f4d75ef43da4ed2a37ba7a8b8daab259.
Missing Differetial revision.
2019-12-11 01:20:40 +05:30
Sourabh Singh Tomar
5eb810ab72 [DWARF5] Start emitting DW_AT_dwo_name when -gdwarf-5 is specified. 2019-12-11 01:18:02 +05:30
Hans Wennborg
62c918ec58 Revert 30e8f80fd5a4 "[DebugInfo] Don't create multiple DBG_VALUEs when sinking"
This caused non-determinism in the compiler, see command on the Phabricator
code review.

> This patch addresses a performance problem reported in PR43855, and
> present in the reapplication in in 001574938e5. It turns out that
> MachineSink will (often) move instructions to the first block that
> post-dominates the current block, and then try to sink further. This
> means if we have a lot of conditionals, we can needlessly create large
> numbers of DBG_VALUEs, one in each block the sunk instruction passes
> through.
>
> To fix this, rather than immediately sinking DBG_VALUEs, record them in
> a pass structure. When sinking is complete and instructions won't be
> sunk any further, new DBG_VALUEs are added, avoiding lots of
> intermediate DBG_VALUE $noregs being created.
>
> Differential revision: https://reviews.llvm.org/D70676
2019-12-10 19:20:11 +01:00
Jeremy Morse
e640a69d80 [DebugInfo] Nerf placeDbgValues, with prejudice
CodeGenPrepare::placeDebugValues moves variable location intrinsics to be
immediately after the Value they refer to. This makes tracking of locations
very easy; but it changes the order in which assignments appear to the
debugger, from the source programs order to the order in which the
optimised program computes values. This then leads to PR43986 and PR38754,
where variable locations that were in a conditional block are made
unconditional, which is highly misleading.

This patch adjusts placeDbgValues to only re-order variable location
intrinsics if they use a Value before it is defined, significantly reducing
the damage that it does. This is still not 100% safe, but the rest of
CodeGenPrepare needs polishing to correctly update debug info when
optimisations are performed to fully fix this.

This will probably break downstream debuginfo tests -- if the
instruction-stream position of variable location changes isn't the focus of
the test, an easy fix should be to manually apply placeDbgValues' behaviour
to the failing tests, moving dbg.value intrinsics next to SSA variable
definitions thus:

  %foo = inst1
  %bar = ...
  %baz = ...
  void call @llvm.dbg.value(metadata i32 %foo, ...

to

  %foo = inst1
  void call @llvm.dbg.value(metadata i32 %foo, ...
  %bar = ...
  %baz = ...

This should return your test to exercising whatever it was testing before.

Differential Revision: https://reviews.llvm.org/D58453
2019-12-09 12:52:10 +00:00
James Henderson
6fc6c6773a [test][tools] Add missing and improve testing
Mostly this adds testing for certain aliases in more explicit ways.
There are also a few tidy-ups, and additions of missing testing, where
the feature was either not tested at all, or not tested explicitly and
sufficiently.

Reviewed by: MaskRay, rupprecht, grimar

Differential Revision: https://reviews.llvm.org/D71116
2019-12-09 12:24:23 +00:00
David Stenberg
860d42802f [DebugInfo] Make describeLoadedValue() reg aware
Summary:
Currently the describeLoadedValue() hook is assumed to describe the
value of the instruction's first explicit define. The hook will not be
called for instructions with more than one explicit define.

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

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

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

This also allows us to handle cases like this:

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

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

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

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

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: djtodoro, vsk

Subscribers: ormris, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D70431
2019-12-09 10:47:49 +01:00
David Stenberg
d53d7803aa Revert "[DebugInfo] Make describeLoadedValue() reg aware"
This reverts commit 3cd93a4efcdeabeb20cb7bec9fbddcb540d337a1.
I'll recommit with a well-formatted arcanist commit message.
2019-12-09 10:45:13 +01:00
David Stenberg
c50f1b7c1a [DebugInfo] Make describeLoadedValue() reg aware
Currently the describeLoadedValue() hook is assumed to describe the
value of the instruction's first explicit define. The hook will not be
called for instructions with more than one explicit define.

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

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

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

This also allows us to handle cases like this:

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

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

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

I have not found a case where it would be useful to describe parameters
using implicit defines, so in this patch the hook is still only invoked
for explicit defines of forwarding registers.
2019-12-09 10:44:17 +01:00
Jeremy Morse
648a9901c3 Attempt to fix a debuginfo test that wasn't as generic as I thought
An ARM buildbot croaks when this test doesn't have a triple specified:

  http://lab.llvm.org:8011/builders/clang-cmake-armv7-quick/builds/12021/

Move the test to the X86 directory and put an x86_64 triple on the
llc command line.
2019-12-06 12:51:58 +00:00
Jeremy Morse
765a5a757e [DebugInfo][CGP] Update dbg.values when sinking address computations
One of CodeGenPrepare's optimizations is to duplicate address calculations
into basic blocks, so that as much information as possible can be folded
into memory addressing operands. This is great -- but the dbg.value
variable location intrinsics are not updated in the same way. This can lead
to dbg.values referring to address computations in other blocks that will
never be encoded into the DAG, while duplicate address computations are
performed locally that could be used by the dbg.value. Some of these (such
as non-constant-offset GEPs) can't be salvaged past.

Fix this by, whenever we duplicate an address computation into a block,
looking for dbg.value users of the original memory address in the same
block, and redirecting those to the local computation.

Differential Revision: https://reviews.llvm.org/D58403
2019-12-06 11:27:19 +00:00
Jeremy Morse
de89d246d7 [DebugInfo] Don't create multiple DBG_VALUEs when sinking
This patch addresses a performance problem reported in PR43855, and
present in the reapplication in in 001574938e5. It turns out that
MachineSink will (often) move instructions to the first block that
post-dominates the current block, and then try to sink further. This
means if we have a lot of conditionals, we can needlessly create large
numbers of DBG_VALUEs, one in each block the sunk instruction passes
through.

To fix this, rather than immediately sinking DBG_VALUEs, record them in
a pass structure. When sinking is complete and instructions won't be
sunk any further, new DBG_VALUEs are added, avoiding lots of
intermediate DBG_VALUE $noregs being created.

Differential revision: https://reviews.llvm.org/D70676
2019-12-05 15:52:20 +00:00
Jeremy Morse
57748093a5 [DebugInfo] Don't reorder DBG_VALUEs when sunk
Fix part of PR43855, resolving a problem that comes from the reapplication
in 001574938e5. If we have two DBG_VALUE insts in a block that specify
the location of the same variable, for example:

   %0 = someinst
   DBG_VALUE %0, !123, !DIExpression()
   %1 = anotherinst
   DBG_VALUE %1, !123, !DIExpression()

if %0 were to sink, the corresponding DBG_VALUE would sink too, past the
next DBG_VALUE, effectively re-ordering assignments. To fix this, I've
added a SeenDbgVars set recording what variable locations have been seen in
a block already (working bottom up), and now flag DBG_VALUEs that would
pass a later DBG_VALUE for the same variable.

NB, this only works for repeated DBG_VALUEs in the same basic block, the
general case involving control flow is much harder, which I've written
up in PR44117.

Differential revision: https://reviews.llvm.org/D70672
2019-12-05 15:52:20 +00:00
Jeremy Morse
4ecf048a1c [DebugInfo] Re-apply two patches to MachineSink
These were:
 * D58386 / f5e1b718a67 / reverted in d382a8a768b
 * D58238 / ee50590e168 / reverted in a8db456b53a

Of which the latter has a performance regression tracked in PR43855,
fixed by D70672 / D70676, which will be committed atomically with this
reapplication.

Contains a minor difference to account for a change in the IsCopyInstr
signature.
2019-12-05 15:52:20 +00:00
Pavel Labath
c389de3c21 [llvm/DWARF] Return section offset from DWARFUnit::get{Loc,Rng}listOffset
Summary:
Currently these function return the raw content of the appropriate table
header, which means they are relative to the DW_AT_{loc,rng}list_base,
and one has to relocate them in order to do anything.

This changes the functions to perform the relocation themselves, which
seems more clearer, particularly as they are sitting right next to the
find{Rng,Loc}listFromOffset functions, but one *cannot* simply take the
result of these functions and take pass them there.

The only effect of this patch is to change what value is dumped for the
DW_AT_ranges attribute, which I think is for the better, as previously
the values appeared to point into thin air.

(The main reason I am looking at this is because I was trying to
implement equivalent functionality in lldb's DWARFUnit, and was stumped
by this behavior.

Reviewers: dblaikie, JDevlieghere, aprantl

Subscribers: hiraditya, llvm-commits, SouraVX

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71006
2019-12-05 12:35:09 +01:00
David Stenberg
57331dc9d0 [DebugInfo] Handle call site values for instructions before call bundle
Summary:
If a call is bundled then the code that looks for instructions that
produce parameter values would break when reaching the call's bundle
header, due to the `ifCall(/*AnyInBundle*/)` invocation returning true.

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

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: aprantl, vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D71024
2019-12-05 11:50:41 +01:00
Djordje Todorovic
8aed5aaf2e Reland "[LiveDebugValues] Introduce entry values of unmodified params"
Relanding this after resolving the cause of the test failure.
2019-12-05 11:10:49 +01:00
Petr Hosek
fbbc57aefb [llvm-symbolizer] Support debug file lookup using build ID
Build ID is a protocol for looking up debug files that's already
supported by various tools including debuggers. For example, when
locating debug files, gdb would check the following directories:

- /usr/lib/debug/.build-id/ab/cdef1234.debug
- /usr/bin/ls.debug
- /usr/bin/.debug/ls.debug
- /usr/lib/debug/usr/bin/ls.debug

llvm-symbolizer currently consults all of these except for build ID
based one. This patch implements support for build ID lookup. The
set of debug directories to search is specified by the new option:
--debug-file-directory, whose name matches the debug-file-directory
variable used by gdb for the same purpose.

Differential Revision: https://reviews.llvm.org/D70759
2019-12-04 15:07:56 -08:00