Commit Graph

1739 Commits

Author SHA1 Message Date
Gui Andrade ff7900d5de [LLVM] Accept `noundef` attribute in function definitions/calls
The `noundef` attribute indicates an argument or return value which
may never have an undef value representation.

This patch allows LLVM to parse the attribute.

Differential Revision: https://reviews.llvm.org/D83412
2020-07-08 19:02:04 +00:00
Guillaume Chatelet 74c723757e [NFC] Adding the align attribute on Atomic{CmpXchg|RMW}Inst
This is the first step to add support for the align attribute to AtomicRMWInst and AtomicCmpXchgInst.
Next step is to add support in IRBuilder and BitcodeReader.
Bug: https://bugs.llvm.org/show_bug.cgi?id=27168

Differential Revision: https://reviews.llvm.org/D83136
2020-07-07 09:54:13 +00:00
Matt Arsenault b091c9a3e1 LLParser: Accept align(N) as new syntax for parameter attribute
Every other value parameter attribute uses parentheses, so accept this
as the preferred modern syntax. Updating everything to use the new
syntax is left for a future change.
2020-06-26 18:10:21 -04:00
Christopher Tetreault 433c9adf7b [SVE] Remove calls to VectorType::getNumElements from AsmParser
Reviewers: efriedma, RKSimon, c-rhodes, fpetrogalli

Reviewed By: fpetrogalli

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82208
2020-06-23 14:31:49 -07:00
Qiu Chaofan e62912b190 [LLParser] Delete temp CallInst when error occurs
Only functions with floating-point return type accepts fast-math flags.
When adding such flags to function returning integer, we'll see a crash,
because there's still an undeleted value referencing the argument. This
patch manually removes the temporary instruction when error occurs.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D78355
2020-06-16 11:41:25 +08:00
Vitaly Buka 4666953ce2 [StackSafety] Add info into function summary
Summary:
This patch adds optional field into function summary,
implements asm and bitcode serialization. YAML
serialization is omitted and can be added later if
needed.

This patch includes this information into summary only
if module contains at least one sanitize_memtag function.
In a near future MTE is the user of the analysis.
Later if needed we can provede more direct control
on when information is included into summary.

Reviewers: eugenis

Subscribers: hiraditya, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80908
2020-06-10 02:43:28 -07:00
Hiroshi Yamauchi a7fa35a629 [ThinLTO] Compute the basic block count across modules.
Summary:
Count the per-module number of basic blocks when the module summary is computed
and sum them up during Thin LTO indexing.

This is used to estimate the working set size under the partial sample PGO.

This is split off of D79831.

Reviewers: davidxl, espindola

Subscribers: emaste, inglorion, hiraditya, MaskRay, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80403
2020-05-28 10:33:05 -07:00
Alok Kumar Sharma d20bf5a725 [DebugInfo] Upgrade DISubrange to support Fortran dynamic arrays
This patch upgrades DISubrange to support fortran requirements.

Summary:
Below are the updates/addition of fields.
lowerBound - Now accepts signed integer or DIVariable or DIExpression,
earlier it accepted only signed integer.
upperBound - This field is now added and accepts signed interger or
DIVariable or DIExpression.
stride - This field is now added and accepts signed interger or
DIVariable or DIExpression.
This is required to describe bounds of array which are known at runtime.

Testing:
unit test cases added (hand-written)
check clang
check llvm
check debug-info

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D80197
2020-05-28 13:46:41 +05:30
Eli Friedman 4f04db4b54 AllocaInst should store Align instead of MaybeAlign.
Along the lines of D77454 and D79968.  Unlike loads and stores, the
default alignment is getPrefTypeAlign, to match the existing handling in
various places, including SelectionDAG and InstCombine.

Differential Revision: https://reviews.llvm.org/D80044
2020-05-16 14:53:16 -07:00
Eli Friedman 0ec5f50196 Harden IR and bitcode parsers against infinite size types.
If isSized is passed a SmallPtrSet, it uses that set to catch infinitely
recursive types (for example, a struct that has itself as a member).
Otherwise, it just crashes on such types.
2020-05-16 14:24:51 -07:00
Simon Pilgrim 43bf2be4d9 LLParser.cpp - remove headers explicitly included in LLParser.h. NFC.
Don't duplicate module header includes.
2020-05-16 15:00:56 +01:00
Eli Friedman 11aa3707e3 StoreInst should store Align, not MaybeAlign
This is D77454, except for stores.  All the infrastructure work was done
for loads, so the remaining changes necessary are relatively small.

Differential Revision: https://reviews.llvm.org/D79968
2020-05-15 12:26:58 -07:00
Nikita Popov f89f7da999 [IR] Convert null-pointer-is-valid into an enum attribute
The "null-pointer-is-valid" attribute needs to be checked by many
pointer-related combines. To make the check more efficient, convert
it from a string into an enum attribute.

In the future, this attribute may be replaced with data layout
properties.

Differential Revision: https://reviews.llvm.org/D78862
2020-05-15 19:41:07 +02:00
Ties Stuij 8c24f33158 [IR][BFloat] Add BFloat IR type
Summary:
The BFloat IR type is introduced to provide support for, initially, the BFloat16
datatype introduced with the Armv8.6 architecture (optional from Armv8.2
onwards). It has an 8-bit exponent and a 7-bit mantissa and behaves like an IEEE
754 floating point IR type.

This is part of a patch series upstreaming Armv8.6 features. Subsequent patches
will upstream intrinsics support and C-lang support for BFloat.

Reviewers: SjoerdMeijer, rjmccall, rsmith, liutianle, RKSimon, craig.topper, jfb, LukeGeeson, sdesmalen, deadalnix, ctetreau

Subscribers: hiraditya, llvm-commits, danielkiss, arphaman, kristof.beyls, dexonsmith

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78190
2020-05-15 14:43:43 +01:00
Alok Kumar Sharma 4042ada1c1 [DebugInfo] support for DW_AT_data_location in llvm
This patch adds support for DWARF attribute DW_AT_data_location.

Summary:
Dynamic arrays in fortran are described by array descriptor and
data allocation address. Former is mapped to DW_AT_location and
later is mapped to DW_AT_data_location.

Testing:
unit test cases added (hand-written)
check llvm
check debug-info

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D79592
2020-05-15 11:33:17 +05:30
Eli Friedman 4532a50899 Infer alignment of unmarked loads in IR/bitcode parsing.
For IR generated by a compiler, this is really simple: you just take the
datalayout from the beginning of the file, and apply it to all the IR
later in the file. For optimization testcases that don't care about the
datalayout, this is also really simple: we just use the default
datalayout.

The complexity here comes from the fact that some LLVM tools allow
overriding the datalayout: some tools have an explicit flag for this,
some tools will infer a datalayout based on the code generation target.
Supporting this properly required plumbing through a bunch of new
machinery: we want to allow overriding the datalayout after the
datalayout is parsed from the file, but before we use any information
from it. Therefore, IR/bitcode parsing now has a callback to allow tools
to compute the datalayout at the appropriate time.

Not sure if I covered all the LLVM tools that want to use the callback.
(clang? lli? Misc IR manipulation tools like llvm-link?). But this is at
least enough for all the LLVM regression tests, and IR without a
datalayout is not something frontends should generate.

This change had some sort of weird effects for certain CodeGen
regression tests: if the datalayout is overridden with a datalayout with
a different program or stack address space, we now parse IR based on the
overridden datalayout, instead of the one written in the file (or the
default one, if none is specified). This broke a few AVR tests, and one
AMDGPU test.

Outside the CodeGen tests I mentioned, the test changes are all just
fixing CHECK lines and moving around datalayout lines in weird places.

Differential Revision: https://reviews.llvm.org/D78403
2020-05-14 13:03:50 -07:00
Sourabh Singh Tomar e59744fd9b [DebugInfo] Fortran module DebugInfo support in LLVM
This patch extends DIModule Debug metadata in LLVM to support
Fortran modules. DIModule is extended to contain File and Line
fields, these fields will be used by Flang FE to create debug
information necessary for representing Fortran modules at IR level.

Furthermore DW_TAG_module is also extended to contain these fields.
If these fields are missing, debuggers like GDB won't be able to
show Fortran modules information correctly.

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D79484
2020-05-13 12:52:30 +05:30
Zequan Wu cb22ab7403 Add nomerge function attribute to supress tail merge optimization in simplifyCFG
We want to add a way to avoid merging identical calls so as to keep the
separate debug-information for those calls. There is also an asan
usecase where having this attribute would be beneficial to avoid
alternative work-arounds.

Here is the link to the feature request:
https://bugs.llvm.org/show_bug.cgi?id=42783.

`nomerge` is different from `noline`. `noinline` prevents function from
inlining at callsites, but `nomerge` prevents multiple identical calls
from being merged into one.

This patch adds `nomerge` to disable the optimization in IR level. A
followup patch will be needed to let backend understands `nomerge` and
avoid tail merge at backend.

Reviewed By: asbirlea, rnk

Differential Revision: https://reviews.llvm.org/D78659
2020-05-12 16:49:20 -07:00
Simon Pilgrim 4319c89551 LLParser.h - remove unused ValueHandle.h include. NFC. 2020-05-09 15:08:48 +01:00
Arthur Eubanks 3b0450acec Add IR constructs for preallocated (inalloca replacement)
Add llvm.call.preallocated.{setup,arg} instrinsics.
Add "preallocated" operand bundle which takes a token produced by llvm.call.preallocated.setup.
Add "preallocated" parameter attribute, which is like byval but without the copy.

Verifier changes for these IR constructs.

See https://github.com/rnk/llvm-project/blob/call-setup-docs/llvm/docs/CallSetup.md

Subscribers: hiraditya, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74651
2020-04-27 16:15:50 -07:00
Simon Pilgrim d7593e3d2c LLParser.h - remove unnecessary Module.h include. NFC. 2020-04-24 15:33:10 +01:00
Simon Pilgrim e5fe6cc251 LLLexer.h - reduce SourceMgr.h include to SMLoc.h. NFC
We only need the SMLoc definition and the SourceMgr forward declaration.
2020-04-24 13:27:56 +01:00
Simon Pilgrim 6f2d64696d [AsmParser] Remove unused forward declarations. NFC. 2020-04-22 14:01:51 +01:00
David Blaikie ab093bfed7 Recommit: DebugInfo: Fix rangesBaseAddress DICompileUnit bitcode serialization/deserialization
Recommits c51b45e32e
Reverted in b350c666ab due to some
(Google-internal) regressions I cannot reproduce... (so we'll see if
they reproduce this time around)
2020-04-20 17:29:04 -07:00
Eli Friedman 9b9454af8a Require "target datalayout" to be at the beginning of an IR file.
This will allow us to use the datalayout to disambiguate other
constructs in IR, like load alignment. Split off from D78403.

Differential Revision: https://reviews.llvm.org/D78413
2020-04-20 11:55:49 -07:00
LemonBoy aad3d578da [DebugInfo] Change DIEnumerator payload type from int64_t to APInt
This allows the representation of arbitrarily large enumeration values.
See https://lists.llvm.org/pipermail/llvm-dev/2017-December/119475.html for context.

Reviewed By: andrewrk, aprantl, MaskRay

Differential Revision: https://reviews.llvm.org/D62475
2020-04-18 12:49:31 -07:00
Simon Pilgrim 2aef5b62c9 [cmake] LLVMAsmParser - add include/llvm/ASMParser header path
Copy + paste typo meant we were picking up the include/llvm/Analysis path instead
2020-04-18 12:31:40 +01:00
Simon Pilgrim b9a8e787ae Parser.h/cpp - cleanup includes and forward declaration. NFC.
Parser.h - Reduce MemoryBuffer.h include to just the necessary StringRef.h include and MemoryBufferRef forward declaration
Parser.cpp - Remove unused raw_ostream.h include
2020-04-16 13:15:32 +01:00
Christopher Tetreault 2a922da3a9 Clean up usages of asserting vector getters in Type
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.

Reviewers: dexonsmith, sdesmalen, efriedma

Reviewed By: sdesmalen

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77274
2020-04-10 13:58:11 -07:00
Eli Friedman 1ee6ec2bf3 Remove "mask" operand from shufflevector.
Instead, represent the mask as out-of-line data in the instruction. This
should be more efficient in the places that currently use
getShuffleVector(), and paves the way for further changes to add new
shuffles for scalable vectors.

This doesn't change the syntax in textual IR. And I don't currently plan
to change the bitcode encoding in this patch, although we'll probably
need to do something once we extend shufflevector for scalable types.

I expect that once this is finished, we can then replace the raw "mask"
with something more appropriate for scalable vectors.  Not sure exactly
what this looks like at the moment, but there are a few different ways
we could handle it.  Maybe we could try to describe specific shuffles.
Or maybe we could define it in terms of a function to convert a fixed-length
array into an appropriate scalable vector, using a "step", or something
like that.

Differential Revision: https://reviews.llvm.org/D72467
2020-03-31 13:08:59 -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
Teresa Johnson 80bf137fa1 Revert "Restore "[WPD/LowerTypeTests] Delay lowering/removal of type tests until after ICP""
This reverts commit 80d0a137a5, and the
follow on fix in 873c0d0786. It is
causing test failures after a multi-stage clang bootstrap. See
discussion on D73242 and D75201.
2020-03-02 14:02:13 -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
Bill Wendling 23c2a5ce33 Allow "callbr" to return non-void values
Summary:
Terminators in LLVM aren't prohibited from returning values. This means that
the "callbr" instruction, which is used for "asm goto", can support "asm goto
with outputs."

This patch removes all restrictions against "callbr" returning values. The
heavy lifting is done by the code generator. The "INLINEASM_BR" instruction's
a terminator, and the code generator doesn't allow non-terminator instructions
after a terminator. In order to correctly model the feature, we need to copy
outputs from "INLINEASM_BR" into virtual registers. Of course, those copies
aren't terminators.

To get around this issue, we split the block containing the "INLINEASM_BR"
right before the "COPY" instructions. This results in two cheats:

  - Any physical registers defined by "INLINEASM_BR" need to be marked as
    live-in into the block with the "COPY" instructions. This violates an
    assumption that physical registers aren't marked as "live-in" until after
    register allocation. But it seems as if the live-in information only
    needs to be correct after register allocation. So we're able to get away
    with this.

  - The indirect branches from the "INLINEASM_BR" are moved to the "COPY"
    block. This is to satisfy PHI nodes.

I've been told that MLIR can support this handily, but until we're able to
use it, we'll have to stick with the above.

Reviewers: jyknight, nickdesaulniers, hfinkel, MaskRay, lattner

Reviewed By: nickdesaulniers, MaskRay, lattner

Subscribers: rriddle, qcolombet, jdoerfert, MatzeB, echristo, MaskRay, xbolva00, aaron.ballman, cfe-commits, JonChesterfield, hiraditya, llvm-commits, rnk, craig.topper

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D69868
2020-02-24 18:29:06 -08:00
evgeny c85055b203 [Assembler] Emit summary index flags
Differential revision: https://reviews.llvm.org/D74420
2020-02-18 17:49:54 +03:00
Jim Lin 466f8843f5 [NFC] Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h,td}
2020-02-18 10:49:13 +08:00
Teresa Johnson 80d0a137a5 Restore "[WPD/LowerTypeTests] Delay lowering/removal of type tests until after ICP"
This restores commit 748bb5a0f1, along
with a fix for a Chromium test suite build issue (and a new test for
that case).

Differential Revision: https://reviews.llvm.org/D73242
2020-02-11 10:48:05 -08:00
Teresa Johnson 25aa2eef99 Revert "[WPD/LowerTypeTests] Delay lowering/removal of type tests until after ICP"
This reverts commit 748bb5a0f1.

Due to Chromium CFI+ThinLTO test crashes reported on patch.
2020-02-05 19:27:32 -08:00
Christopher Tetreault b03f3fbd6a Reapply: [SVE] Fix bug in simplification of scalable vector instructions
This reverts commit a05441038a, reapplying
commit 31574d38ac
2020-02-05 10:00:09 -08:00
Teresa Johnson 748bb5a0f1 [WPD/LowerTypeTests] Delay lowering/removal of type tests until after ICP
Summary:
Currently type test assume sequences inserted for devirtualization are
removed during WPD. This patch delays their removal until later in the
optimization pipeline. This is an enabler for upcoming enhancements to
indirect call promotion, for example streamlined promotion guard
sequences that compare against vtable address instead of the target
function, when there are small number of possible vtables (either
determined via WPD or by in-progress type profiling). We need the type
tests to correlate the callsites with the address point offset needed in
the compare sequence, and optionally to associated type summary info
computed during WPD.

This depends on work in D71913 to enable invocation of LowerTypeTests to
drop type test assume sequences, which will now be invoked following ICP
in the ThinLTO post-LTO link pipelines, and also after the existing
export phase LowerTypeTests invocation in regular LTO (which is already
after ICP). We cannot simply move the existing import phase
LowerTypeTests pass later in the ThinLTO post link pipelines, as the
comment in PassBuilder.cpp notes (it must run early because when
performing CFI other passes may disturb the sequences it looks for).

This necessitated adding a new type test resolution "Unknown" that we
can use on the type test assume sequences previously removed by WPD,
that we now want LTT to ignore.

Depends on D71913.

Reviewers: pcc, evgeny777

Subscribers: mehdi_amini, Prazek, hiraditya, steven_wu, dexonsmith, arphaman, davidxl, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73242
2020-02-05 08:59:48 -08:00
Reid Kleckner a05441038a Revert "[SVE] Fix bug in simplification of scalable vector instructions"
This reverts commit 31574d38ac.

The newly added shufflevector test does not pass locally on either of my
workstations.
2020-02-03 11:12:09 -08:00
Christopher Tetreault 31574d38ac [SVE] Fix bug in simplification of scalable vector instructions
Summary:
* Most of the simplifications in SimplifyShuffleVectorInst depend on the
concrete value of, or the length of the mask vector. For scalable
vectors, this cannot be known at compile time.
** for these tests, detect if the vector is scalable before attempting
the transformation
* The functions ShuffleVectorInst::getMaskValue and
ShuffleVectorInst::getShuffleMask access the value of the constant mask.
However, since the length of the mask is unknown at compile time, these
function do not work for scalable vectors. Add asserts to ensure that
the input mask is not scalable

Reviewers: efriedma, sdesmalen, apazos, chrisj, huihuiz

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73555
2020-02-03 10:15:56 -08:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Teresa Johnson 9c2eb220ed [ThinLTO] Summarize vcall_visibility metadata
Summary:
Second patch in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html

Summarize vcall_visibility metadata in ThinLTO global variable summary.

Depends on D71907.

Reviewers: pcc, evgeny777, steven_wu

Subscribers: mehdi_amini, Prazek, inglorion, hiraditya, dexonsmith, arphaman, ostannard, llvm-commits, cfe-commits, davidxl

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71911
2020-01-23 13:19:56 -08:00
Evgeny Leviant 3593b5b3e9 [llvm-as] Fix assembling of index with multiple summaries sharing single GUID
Differential revision: https://reviews.llvm.org/D73091
2020-01-22 01:09:13 -08:00
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