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
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
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.
This is for the case where -gmlt -gsplit-dwarf -fsplit-dwarf-inlining
are used together in some but not all units during LTO (or, in the
reduced case, even without LTO) - ensuring that no split dwarf is used
(because split-dwarf-inlining puts the same data in the .o file, so
there's no need to duplicate it into the .dwo file)
The loclists_table_base was being overwritten for each CU even though
only one loclists contribution is made so everything but the last CU
would have a label that was never defined and fail to assemble.
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
That patch fixes incompatible compilation unit type (DW_UT_skeleton) and root DIE (DW_TAG_compile_unit) error.
cat split-dwarf.cpp
int main()
{
int a = 1;
return 0;
}
clang++ -O -g -gsplit-dwarf -gdwarf-5 split-dwarf.cpp; llvm-dwarfdump --verify ./a.out | grep skeleton
error: Compilation unit type (DW_UT_skeleton) and root DIE (DW_TAG_compile_unit) do not match.
The fix is to change DW_TAG_compile_unit into DW_TAG_skeleton_unit when skeleton file is generated.
Differential Revision: https://reviews.llvm.org/D70880
This patch adds support for debug_macinfo.dwo section[pre-standardized]
to llvm and llvm-dwarfdump.
Reviewers: probinson, dblaikie, aprantl, jini.susan.george, alok
Differential Revision: https://reviews.llvm.org/D70705
Tags: #debug-info #llvm
The original commit message follows.
This patch adds support for debug_loclists.dwo section in llvm and llvm-dwarfdump.
Also Fixes PR43622, PR43623.
Reviewers: dblaikie, probinson, labath, aprantl, jini.susan.george
Differential Revision: https://reviews.llvm.org/D69462
This reverts commit 81b0a3284af1dcef26e56b0de9fd74002083c471.
Will Re-apply, with updated Differtial Revision, for automatic closure of
Phabricator review.
This patch adds support for debug_loclists.dwo section in llvm and llvm-dwarfdump.
Also Fixes PR43622, PR43623.
Reviewers: dblaikie, probinson, labath, aprantl, jini.susan.george
https://reviews.llvm.org/D69462
Summary:
Assert in getFunctionLocalOffsetAfterInsn() fails when processing a call
MachineInstr inside a bundle and compiling with debug info. This is
because labels are added by DwarfDebug::beginInstruction() which is
called for each top-level MI by EmitFunctionBody()'s for-loop iteration
but constructCallSiteEntryDIEs() which calls
getFunctionLocalOffsetAfterInsn() iterates over all MIs.
This commit modifies constructCallSiteEntryDIEs() to get the associated
bundle MI for call MIs inside a bundle and use that to when calling
getFunctionLocalOffsetAfterInsn() and getLabelAfterInsn(). It also skips
loop iterations for bundle MIs since the loop statements are concerned
with debug info for each physical instructions and bundles represent a
group of instructions. It also fix the comment about PCAddr since the
code is getting the return address and not the call address.
Reviewers: dstenb, vsk, aprantl, djtodoro, dblaikie, NikolaPrica
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70293
This only implements the non-dwo part, but loclistx is necessary to use
location lists in DWARFv5, so it's a precursor to that work - and
generally reduces relocations (only using one reloc, then
indexes/relative offsets for all location list references) in non-split
DWARF.
The macinfo support was broken for LTO situations, by terminating
macinfo lists only once - multiple macinfo contributions were correctly
labeled, but they all continued/flowed into later contributions until
only one terminator appeared at the end of the section.
Correctly terminate each contribution & fix the parsing to handle this
situation too. The parsing fix is also necessary for dumping linked
binaries - the previous code would stop at the end of the first
contribution - missing all later contributions in a linked binary.
It'd be nice to improve the dumping to print the offsets of each
contribution so it'd be easier to know which CU AT_macro_info refers to
which macinfo contribution.
Extend the describeLoadedValue() with support for target specific ARM and
AArch64 instructions interpretation. The patch provides specialization for
ADD and SUB operations that include a register and an immediate/offset
operand. Some of the instructions can operate with global string addresses
or constant pool indexes but such cases are omitted since we currently lack
flexible support for processing such operands at DWARF production stage.
Patch by Nikola Prica
Differential Revision: https://reviews.llvm.org/D67556
There's no need to have more than one of these (there can be two
DwarfFiles - one for the .o, one for the .dwo - but only one loc/loclist
section (either in the .o or the .dwo) & certainly one per
DebugLocStream, which is currently singular in DwarfDebug)
llvm-svn: 375183
Summary:
Internally in LLVM's metadata we use DW_OP_entry_value operations with
the same semantics as DWARF; that is, its operand specifies the number
of bytes that the entry value covers.
At the time of emitting entry values we don't know the emitted size of
the DWARF expression that the entry value will cover. Currently the size
is hardcoded to 1 in DIExpression, and other values causes the verifier
to fail. As the size is 1, that effectively means that we can only have
valid entry values for registers that can be encoded in one byte, which
are the registers with DWARF numbers 0 to 31 (as they can be encoded as
single-byte DW_OP_reg0..DW_OP_reg31 rather than a multi-byte
DW_OP_regx). It is a bit confusing, but it seems like llvm-dwarfdump
will print an operation "correctly", even if the byte size is less than
that, which may make it seem that we emit correct DWARF for registers
with DWARF numbers > 31. If you instead use readelf for such cases, it
will interpret the number of specified bytes as a DWARF expression. This
seems like a limitation in llvm-dwarfdump.
As suggested in D66746, a way forward would be to add an internal
variant of DW_OP_entry_value, DW_OP_LLVM_entry_value, whose operand
instead specifies the number of operations that the entry value covers,
and we then translate that into the byte size at the time of emission.
In this patch that internal operation is added. This patch keeps the
limitation that a entry value can only be applied to simple register
locations, but it will fix the issue with the size operand being
incorrect for DWARF numbers > 31.
Reviewers: aprantl, vsk, djtodoro, NikolaPrica
Reviewed By: aprantl
Subscribers: jyknight, fedor.sergeev, hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D67492
llvm-svn: 374881
Summary:
DWARF's DW_OP_entry_value operation has two operands; the first is a
ULEB128 operand that specifies the size of the second operand, which is
a DWARF block. This means that we need to be able to pre-calculate and
emit the size of DWARF expressions before emitting them. There is
currently no interface for doing this in DwarfExpression, so this patch
introduces that.
When implementing this I initially thought about running through
DwarfExpression's emission two times; first with a temporary buffer to
emit the expression, in order to being able to calculate the size of
that emitted data. However, DwarfExpression is a quite complex state
machine, so I decided against that, as it seemed like the two runs could
get out of sync, resulting in incorrect size operands. Therefore I have
implemented this in a way that we only have to run DwarfExpression once.
The idea is to emit DWARF to a temporary buffer, for which it is
possible to query the size. The data in the temporary buffer can then be
emitted to DwarfExpression's main output.
In the case of DIEDwarfExpression, a temporary DIE is used. The values
are all allocated using the same BumpPtrAllocator as for all other DIEs,
and the values are then transferred to the real value list. In the case
of DebugLocDwarfExpression, the temporary buffer is implemented using a
BufferByteStreamer which emits to a buffer in the DwarfExpression
object.
Reviewers: aprantl, vsk, NikolaPrica, djtodoro
Reviewed By: aprantl
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D67768
llvm-svn: 374879
Summary:
This addresses a bug in collectCallSiteParameters() where call site
immediates would be truncated from int64_t to unsigned.
This fixes PR43525.
Reviewers: djtodoro, NikolaPrica, aprantl, vsk
Reviewed By: aprantl
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D68869
llvm-svn: 374770
Unify the range and loc emission (for both DWARFv4 and DWARFv5 style lists) and take advantage of that unification to use strategic base addresses for loclists.
Differential Revision: https://reviews.llvm.org/D68620
llvm-svn: 374600
Doing this makes MSVC complain that `empty(someRange)` could refer to
either C++17's std::empty or LLVM's llvm::empty, which previously we
avoided via SFINAE because std::empty is defined in terms of an empty
member rather than begin and end. So, switch callers over to the new
method as it is added.
https://reviews.llvm.org/D68439
llvm-svn: 373935
Brings this struct in line with the RangeSpan class so they might
eventually be used by common template code for generating range/loc
lists with less duplicate code.
llvm-svn: 373540
This is an effort to make RangeSpan and DebugLocStream::Entry more
similar to share code for their emission (to reuse the more complicated
code for using (& choosing when to use) base address selection entries,
etc).
It didn't seem like this struct was worth the complexity of
encapsulation - when the members could be initialized by the ctor to any
value (no validation) and the type is assignable (so there's no
mutability or other constraint being implemented by its interface).
llvm-svn: 373533
DIFlagBlockByRefStruct is an unused DIFlag that originally was used by
clang to express (Objective-)C block captures in debug info. For the
last year Clang has been emitting complex DIExpressions to describe
block captures instead, which makes all the code supporting this flag
redundant.
This patch removes the flag and all supporting "dead" code, so we can
reuse the bit for something else in the future.
Since this only affects debug info generated by Clang with the block
extension this mostly affects Apple platforms and I don't have any
bitcode compatibility concerns for removing this. The Verifier will
reject debug info that uses the bit and thus degrade gracefully when
LTO'ing older bitcode with a newer compiler.
rdar://problem/44304813
Differential Revision: https://reviews.llvm.org/D67453
llvm-svn: 372272
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet, JDevlieghere, alexshap, rupprecht, jhenderson
Subscribers: sdardis, nemanjai, hiraditya, kbarton, jakehehrlich, jrtc27, MaskRay, atanasyan, jsji, seiya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D67499
llvm-svn: 371742
Emit debug entry values using standard DWARF5 opcodes when the debugger
tuning is set to lldb.
Differential Revision: https://reviews.llvm.org/D67410
llvm-svn: 371666
Summary:
Add zero-materializing XORs to X86's describeLoadedValue() hook in order
to produce call site values.
I have had to change the defs logic in collectCallSiteParameters() a bit
to be able to describe the XORs. The XORs implicitly define $eflags,
which would cause them to never be considered, due to a guard condition
that I->getNumDefs() is one. I have changed that condition so that we
now only consider instructions where a forwarded register overlaps with
the instruction's single explicit define. We still need to collect the implicit
defines of other forwarded registers to remove them from the work list.
I'm not sure how to move towards supporting instructions with multiple
explicit defines, cases where forwarded register are implicitly defined,
and/or cases where an instruction produces values for multiple forwarded
registers. Perhaps the describeLoadedValue() hook should take a register
argument, and we then leave it up to the hook to describe the loaded
value in that register? I have not yet encountered a situation where
that would be necessary though.
Reviewers: aprantl, vsk, djtodoro, NikolaPrica
Reviewed By: vsk
Subscribers: ychen, hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D67225
llvm-svn: 371333
Summary:
This changes the ParamLoadedValue pair which the describeLoadedValue()
hook returns so that MachineOperand objects are returned instead of
pointers.
When describing call site values we may need to describe operands which
are not part of the instruction. One such example is zero-materializing
XORs on x86, which I have implemented support for in a child revision.
Instead of having to return a pointer to an operand stored somewhere
outside the instruction, start returning objects directly instead, as
that simplifies the code.
The MachineOperand class only holds POD members, and on x86-64 it is 32
bytes large. That combined with copy elision means that the overhead of
returning a machine operand object from the hook does not become very
large.
I benchmarked this on a 8-thread i7-8650U machine with 32 GB RAM. The
benchmark consisted of building a clang 8.0 binary configured with:
-DCMAKE_BUILD_TYPE=RelWithDebInfo \
-DLLVM_TARGETS_TO_BUILD=X86 \
-DLLVM_USE_SANITIZER=Address \
-DCMAKE_CXX_FLAGS="-Xclang -femit-debug-entry-values -stdlib=libc++"
The average wall clock time increased by 4 seconds, from 62:05 to
62:09, which is an 0.1% increase.
Reviewers: aprantl, vsk, djtodoro, NikolaPrica
Reviewed By: vsk
Subscribers: hiraditya, ychen, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D67261
llvm-svn: 371332
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).
Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor
Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&
Depends on D65919
Reviewers: arsenm, bogner, craig.topper, RKSimon
Reviewed By: arsenm
Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65962
llvm-svn: 369041
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
Summary: There are places where a case that debug label scope has an extra lexical block file is not considered properly. The modified test won't pass without this patch.
Reviewers: aprantl, HsiangKai
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66187
llvm-svn: 368891
This updates all libraries and tools in LLVM Core to use 64-bit offsets
which directly or indirectly come to DataExtractor.
Differential Revision: https://reviews.llvm.org/D65638
llvm-svn: 368014
