2843 Commits

Author SHA1 Message Date
Igor Kudrin
8306f55bfa [DWARF] Eliminate the DWARFDebugNames::Header::Padding field.
The padding field is reserved for DWARF and does not contain any useful
information. No need to read, store and report it.

Differential Revision: https://reviews.llvm.org/D73042
2020-01-23 15:11:58 +07:00
Igor Kudrin
5a9ef6c15f [DWARF] Support 64-bit DWARF in .debug_pubnames and similar tables.
Differential Revision: https://reviews.llvm.org/D73103
2020-01-23 14:51:00 +07:00
Igor Kudrin
6332990721 [DWARF] Support DWARF64 in DWARFDebugArangeSet.
This allows parsing Address Range Tables in the 64-bit DWARF format.

Differential Revision: https://reviews.llvm.org/D71876
2020-01-23 12:41:05 +07:00
Igor Kudrin
dcff3961c2 [DWARF] Return Error from DWARFDebugArangeSet::extract().
This helps to detect and report parsing errors better.
The patch follows the ideas of LLDB's patches D59370 and D59381.

It adds tests for valid and some invalid cases. More checks and
tests to come. Note that the patch fixes validation of the Length
field because the value does not include the field itself.

The existing users are updated to show the error messages.

Differential Revision: https://reviews.llvm.org/D71875
2020-01-23 12:41:05 +07:00
Igor Kudrin
5e017c12d2 [DWARF] Allow empty address range tables.
Empty address range tables are allowed by the DWARF standard;
Moreover, generating them is recommended as a best practice, see
http://wiki.dwarfstd.org/index.php?title=Best_Practices#Generating_.debug_aranges_data

Differential Revision: https://reviews.llvm.org/D71931
2020-01-23 12:41:04 +07:00
Fangrui Song
55c81d4282 [test] Use yaml2obj -o %t instead of > %t
To improve consistency and avoid unneeded shell feature (output
redirection).

While here, make other changes to improve consistency

--docnum 1 => --docnum=1
-docnum=x => --docnum=x
2020-01-21 17:20:18 -08:00
Awanish Pandey
84c4c87e04 Recommit "[DWARF5][DebugInfo]: Added support for DebugInfo generation for auto return type for C++ member functions."
Summary:
This was reverted in 328e0f3dcac52171b8cdedeaba22c98e7fbb75ea due to
chromium bot failure. This revision addresses that case.

Original commit message:
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
2020-01-20 15:13:13 +05:30
Fangrui Song
26ba1f77b5 [DebugInfo][test] Change two MIR tests to use -start-before=livedebugvalues instead of -start-after=patchable-function
To break order dependency between livedebugvalues and patchable-function.
2020-01-19 00:09:46 -08:00
Adrian Prantl
7b30370e5b Move the sysroot attribute from DIModule to DICompileUnit
[this re-applies c0176916a4824812d25a5a22c4ff7c95857b0cd6
 with the correct commit message and phabricator link]

This addresses point 1 of PR44213.
https://bugs.llvm.org/show_bug.cgi?id=44213

The DW_AT_LLVM_sysroot attribute is used for Clang module debug info,
to allow LLDB to import a Clang module from source. Currently it is
part of each DW_TAG_module, however, it is the same for all modules in
a compile unit. It is more efficient and less ambiguous to store it
once in the DW_TAG_compile_unit.

This should have no effect on DWARF consumers other than LLDB.

Differential Revision: https://reviews.llvm.org/D71732
2020-01-17 12:55:40 -08:00
Adrian Prantl
c17aee67f1 Revert "Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot"
This reverts commit 12e479475a896f664fb721f98c2d6805185ac352.

I accidentally landed this patch with the wrong commit message ...
2020-01-17 12:52:36 -08:00
Adrian Prantl
12e479475a 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
2020-01-17 09:36:48 -08:00
Yuanfang Chen
6e24c6037f Revert "[Support] make report_fatal_error abort instead of exit"
This reverts commit 647c3f4e47de8a850ffcaa897db68702d8d2459a.

Got bots failure from sanitizer-windows and maybe others.
2020-01-15 17:52:25 -08:00
Yuanfang Chen
647c3f4e47 [Support] make report_fatal_error abort instead of exit
Summary:
This patch could be treated as a rebase of D33960. It also fixes PR35547.
A fix for `llvm/test/Other/close-stderr.ll` is proposed in D68164. Seems
the consensus is that the test is passing by chance and I'm not
sure how important it is for us. So it is removed like in D33960 for now.
The rest of the test fixes are just adding `--crash` flag to `not` tool.

** The reason it fixes PR35547 is

`exit` does cleanup including calling class destructor whereas `abort`
does not do any cleanup. In multithreading environment such as ThinLTO or JIT,
threads may share states which mostly are ManagedStatic<>. If faulting thread
tearing down a class when another thread is using it, there are chances of
memory corruption. This is bad 1. It will stop error reporting like pretty
stack printer; 2. The memory corruption is distracting and nondeterministic in
terms of error message, and corruption type (depending one the timing, it
could be double free, heap free after use, etc.).

Reviewers: rnk, chandlerc, zturner, sepavloff, MaskRay, espindola

Reviewed By: rnk, MaskRay

Subscribers: wuzish, jholewinski, qcolombet, dschuff, jyknight, emaste, sdardis, nemanjai, jvesely, nhaehnle, sbc100, arichardson, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, lenary, s.egerton, pzheng, cfe-commits, MaskRay, filcab, davide, MatzeB, mehdi_amini, hiraditya, steven_wu, dexonsmith, rupprecht, seiya, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D67847
2020-01-15 17:05:13 -08:00
Vedant Kumar
f0120556c7 [DWARF] Emit DW_AT_call_return_pc as an address
This reverts D53469, which changed llvm's DWARF emission to emit
DW_AT_call_return_pc as a function-local offset. Such an encoding is not
compatible with post-link block re-ordering tools and isn't standards-
compliant.

In addition to reverting back to the original DW_AT_call_return_pc
encoding, teach lldb how to fix up DW_AT_call_return_pc when the address
comes from an object file pointed-to by a debug map. While doing this I
noticed that lldb's support for tail calls that cross a DSO/object file
boundary wasn't covered, so I added tests for that. This latter case
exercises the newly added return PC fixup.

The dsymutil changes in this patch were originally included in D49887:
the associated test should be sufficient to test DW_AT_call_return_pc
encoding purely on the llvm side.

Differential Revision: https://reviews.llvm.org/D72489
2020-01-15 13:02:23 -08:00
Tom Weaver
e7b2d9f470 [DBG][LIVEDEBUGVALUES][NFC] Add Targeted LiveDebugValues Behaviour Tests.
Adds 22 distinct tests that exercise the live-debug-values passes
expected behaviour.

reviewers: aprantl, vsk

Differential revision: https://reviews.llvm.org/D72515
2020-01-14 15:51:11 +00:00
Tom Weaver
b10f6b7112 Revert "[DBG][LIVEDEBUGVALUES][NFC] Add Targeted LiveDebugValues Behaviour Tests."
This reverts commit 35787e3a062a4a21c145137552d20cb1169c74fc.
2020-01-14 15:12:02 +00:00
Tom Weaver
35787e3a06 [DBG][LIVEDEBUGVALUES][NFC] Add Targeted LiveDebugValues Behaviour Tests.
Adds 22 distinct tests that exercise the live-debug-values passes
expected behaviour.

reviewers: aprantl, vsk

Differential revision: https://reviews.llvm.org/D72515
2020-01-14 14:43:30 +00:00
Amy Huang
328e0f3dca Revert "[DWARF5][DebugInfo]: Added support for DebugInfo generation for auto return type for C++ member functions."
This reverts commit c958639098a8702b831952b1a1a677ae19190a55, which
causes a crash. See https://reviews.llvm.org/D70524 for details.
2020-01-13 13:58:14 -08:00
Alex Richardson
894f742acb [MIPS][ELF] Use PC-relative relocations in .eh_frame when possible
When compiling position-independent executables, we now use
DW_EH_PE_pcrel | DW_EH_PE_sdata4. However, the MIPS ABI does not define a
64-bit PC-relative ELF relocation so we cannot use sdata8 for the large
code model case. When using the large code model, we fall back to the
previous behaviour of generating absolute relocations.

With this change clang-generated .o files can be linked by LLD without
having to pass -Wl,-z,notext (which creates text relocations).
This is simpler than the approach used by ld.bfd, which rewrites the
.eh_frame section to convert absolute relocations into relative references.

I saw in D13104 that apparently ld.bfd did not accept pc-relative relocations
for MIPS ouput at some point. However, I also checked that recent ld.bfd
can process the clang-generated .o files so this no longer seems true.

Reviewed By: atanasyan
Differential Revision: https://reviews.llvm.org/D72228
2020-01-13 14:14:03 +00:00
Awanish Pandey
c958639098 [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
f26ed6e47c 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
b350c666ab 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
c51b45e32e 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
cdd25a4c74 [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
a36ddf0aa9 Migrate function attribute "no-frame-pointer-elim"="false" to "frame-pointer"="none" as cleanups after D56351 2019-12-24 16:27:51 -08:00
Fangrui Song
eb16435b5e 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
502a77f125 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
fccac1ec16 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
0a72515d33 [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
6f635f9092 [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
fa4701e197 [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
79daafc903 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
adf7a0a558 [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
44b4b833ad 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
b538a2aa07 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
453dc4d7ec [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
97b5d6bfdc DebugInfo: Fix test fallout from aaa5a5e7ff1aee632aae75311e7c044f710dd0a0 2019-12-18 19:00:40 -08:00
David Blaikie
aaa5a5e7ff 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
89d19d60ad 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
1f3dd83cc1 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
bb1b0bc4e5 [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
399273e5eb 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
ccfab8e459 [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
e5f07080b8 [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
a0aa58dad5 [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
5c7cc6f83d [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
71aaebc824 [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
56232f950d 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
caa4120906 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
30038da15b [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