172 Commits

Author SHA1 Message Date
Davide Italiano 5f87415efc [LICM] Try to merge debug locations when sinking.
The current strategy LICM uses when sinking for debuginfo is
that of picking the debug location of one of the uses.
This causes stepping to be wrong sometimes, see, e.g. PR45523.

This patch introduces a generalization of getMergedLocation(),
that operates on a vector of locations instead of two, and try
to merge all them together, and use the new API in LICM.

<rdar://problem/61750950>
2020-04-15 12:29:34 -07:00
Vedant Kumar 526c51e6fd [DwarfDebug] Fix an assertion error when emitting call site info that combines two DW_OP_stack_values
When compiling

```
struct S {
  float w;
};
void f(long w, long b);
void g(struct S s) {
  int w = s.w;
  f(w, w*4);
}
```

I get Assertion failed: ((!CombinedExpr || CombinedExpr->isValid()) && "Combined debug expression is invalid").

That's because we combine two epxressions that both end in DW_OP_stack_value:

```
(lldb) p Expr->dump()
!DIExpression(DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_LLVM_convert, 64, DW_ATE_signed, DW_OP_stack_value)
(lldb) p Param.Expr->dump()
!DIExpression(DW_OP_constu, 4, DW_OP_mul, DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_LLVM_convert, 64, DW_ATE_signed, DW_OP_stack_value)
(lldb) p CombinedExpr->isValid()
(bool) $0 = false
(lldb) p CombinedExpr->dump()
!DIExpression(4097, 32, 5, 4097, 64, 5, 16, 4, 30, 4097, 32, 5, 4097, 64, 5, 159, 159)
```

I believe that in this particular case combining two stack values is
safe, but I didn't want to sink the special handling into
DIExpression::append() because I do want everyone to think about what
they are doing.

Patch by Adrian Prantl.

Fixes PR45181.
rdar://problem/60383095

Differential Revision: https://reviews.llvm.org/D76164
2020-03-17 12:51:49 -07:00
Arlo Siemsen 1478ed69d3 Add support for SHA256 source file checksums in debug info
LLVM currently supports CSK_MD5 and CSK_SHA1 source file checksums in
debug info. This change adds support for CSK_SHA256 checksums.

The SHA256 checksums are supported by the CodeView debug format.

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D75785
2020-03-12 16:32:05 -07:00
Adrian Prantl d5180ea134 Add debug info support for Swift/Clang APINotes.
In order for dsymutil to collect .apinotes files (which capture
attributes such as nullability, Swift import names, and availability),
I want to propose adding an apinotes: field to DIModule that gets
translated into a DW_AT_LLVM_apinotes (path) nested inside
DW_TAG_module. This will be primarily used by LLDB to indirectly
extract the Swift names of Clang declarations that were deserialized
from DWARF.

<rdar://problem/59514626>

Differential Revision: https://reviews.llvm.org/D75585
2020-03-11 18:47:30 -07:00
Adrian Prantl e4e7e44765 Add an SDK attribute to DICompileUnit
This is part of PR44213 https://bugs.llvm.org/show_bug.cgi?id=44213

When importing (system) Clang modules, LLDB needs to know which SDK
(e.g., MacOSX, iPhoneSimulator, ...) they came from. While the sysroot
attribute contains the absolute path to the SDK, this doesn't work
well when the debugger is run on a different machine than the
compiler, and the SDKs are installed in different directories. It thus
makes sense to just store the name of the SDK instead of the absolute
path, so it can be found relative to LLDB.

rdar://problem/51645582

Differential Revision: https://reviews.llvm.org/D75646
2020-03-11 14:14:06 -07:00
Adrian Prantl 5c83bedeca More principled implementation of DISubprogram::describes()
Previously we would also accept DISubprograms that matched in name
only, but this doesn't appear to be necessary any more.

I did a Full and Thin LTO build of Clang and it completed without a warning.

Differential Revision: https://reviews.llvm.org/D75213
2020-03-02 10:03:14 -08:00
Awanish Pandey 7a42babeb8 Reland "[DebugInfo][clang][DWARF5]: Added support for debuginfo generation for defaulted parameters
in C++ templates."

This was reverted in 802b22b5c8 due to
missing .bc file and a chromium bot failure.
https://bugs.chromium.org/p/chromium/issues/detail?id=1057559#c1
This revision address both of them.

Summary:
This patch adds support for debuginfo generation for defaulted
parameters in clang and also extends corresponding DebugMetadata/IR to support this feature.

Reviewers: probinson, aprantl, dblaikie

Reviewed By: aprantl, dblaikie

Differential Revision: https://reviews.llvm.org/D73462
2020-03-02 16:45:48 +05:30
Hans Wennborg 802b22b5c8 Revert "[DebugInfo][clang][DWARF5]: Added support for debuginfo generation for defaulted parameters"
The Bitcode/DITemplateParameter-5.0.ll test is failing:

FAIL: LLVM :: Bitcode/DITemplateParameter-5.0.ll (5894 of 36324)
******************** TEST 'LLVM :: Bitcode/DITemplateParameter-5.0.ll' FAILED ********************
Script:
--
: 'RUN: at line 1';   /usr/local/google/home/thakis/src/llvm-project/out/gn/bin/llvm-dis -o - /usr/local/google/home/thakis/src/llvm-project/llvm/test/Bitcode/DITemplateParameter-5.0.ll.bc | /usr/local/google/home/thakis/src/llvm-project/out/gn/bin/FileCheck /usr/local/google/home/thakis/src/llvm-project/llvm/test/Bitcode/DITemplateParameter-5.0.ll
--
Exit Code: 2

Command Output (stderr):
--

It looks like the Bitcode/DITemplateParameter-5.0.ll.bc file was never checked in.

This reverts commit c2b437d53d.
2020-03-02 09:30:52 +01:00
Awanish Pandey c2b437d53d [DebugInfo][clang][DWARF5]: Added support for debuginfo generation for defaulted parameters
in C++ templates.

Summary:
This patch adds support for debuginfo generation for defaulted
parameters in clang and also extends corresponding DebugMetadata/IR to support this feature.

Reviewers: probinson, aprantl, dblaikie

Reviewed By: aprantl, dblaikie

Differential Revision: https://reviews.llvm.org/D73462
2020-03-02 12:33:05 +05:30
Adrian Prantl 7b30370e5b Move the sysroot attribute from DIModule to DICompileUnit
[this re-applies c0176916a4
 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 12e479475a.

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
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
stozer 89d19d60ad Reapply: [DebugInfo] Correctly handle salvaged casts and split fragments at ISel
This reverts commit 1f3dd83cc1, reapplying
commit bb1b0bc4e5.

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 bb1b0bc4e5.
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
stozer 269a9afe25 [DebugInfo] Make DebugVariable class available in DebugInfoMetadata
The DebugVariable class is a class declared in LiveDebugValues.cpp which
is used to uniquely identify a single variable, using its source
variable, inline location, and fragment info to do so. This patch moves
this class into DebugInfoMetadata.h, making it available in a much
broader scope.
2019-12-03 15:10:56 +00:00
stozer 184d72a7c6 [DebugInfo] Disallow fragmenting DIExpressions with shift operators
DIExpressions with shift operators should not be fragmented for the same
reason as arithmetic operators: carry over cannot be expressed from one
fragment to the other, so an invalid result would be produced.

Differential Revision: https://reviews.llvm.org/D70601
2019-11-26 16:12:22 +00:00
David Stenberg 3889ff82bf [DebugInfo] Refactor DIExpression [SZ]Ext creation into function [NFC]
Summary:
Also, replace the SmallVector with a normal C array.

Reviewers: vsk

Reviewed By: vsk

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70498
2019-11-21 10:44:04 +01:00
Bjorn Pettersson e2549a0a25 [DebugInfo] Fix for DW_OP_LLVM_fragment in DIExpression::isImplicit()
DIExpression::isImplicit() did not handle DW_OP_LLVM_fragment
correctly. It was scanning the elements in the expression by
iterating from the end. But we do not know the position of
ops unless we iterate from the beginning of the expression,
since DW_OP:s and their operands are stored flat in the expression
list. The old code also assumed that a DW_OP_LLVM_fragment
only occupied one element in the expression list, but it actually
occupies three elements.
2019-11-03 17:37:49 +01:00
David Stenberg 1ae2d9a2bd [DebugInfo] Add a DW_OP_LLVM_entry_value operation
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
2019-10-15 11:31:21 +00:00
Simon Pilgrim 30f76caa46 DIExpression::createFragmentExpression - silence static analyzer DIExpression* null dereference warning with an assertion. NFCI.
llvm-svn: 373326
2019-10-01 11:25:38 +00:00
Djordje Todorovic b9973f87c6 Reland "[DwarfDebug] Dump call site debug info"
The build failure found after the rL365467 has been
resolved.

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 367446
2019-07-31 16:51:28 +00:00
Djordje Todorovic 0739ccd3b5 Revert "[DwarfDebug] Dump call site debug info"
A build failure was found on the SystemZ platform.

This reverts commit 9e7e73578e54cd22b3c7af4b54274d743b6607cc.

llvm-svn: 365886
2019-07-12 09:45:12 +00:00
Djordje Todorovic 01eaae6dd1 [DwarfDebug] Dump call site debug info
Dump the DWARF information about call sites and call site parameters into
debug info sections.

The patch also provides an interface for the interpretation of instructions
that could load values of a call site parameters in order to generate DWARF
about the call site parameters.

([13/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 365467
2019-07-09 11:33:56 +00:00