Following the commit of #83972 which added COFF support for SPGO, this
patch ports the support of the option -lto-sample-profile that was only
available in the ELF variant of LLD to the COFF variant to enable
running the SPGO passes in the LTO/thinLTO pipelines.
The export names are saved as StringRefs pointing into the COFF
directives. In the case of LTO objects, this can be memory allocated
that is owned by the LTO InputFile, which gets destructed when doing the
compilation.
In the case of LTO objects from an older version of LLVM, which require
being upgraded when loaded, the directives string gets destructed, while
when using LTO objects of a matching version (the common case), the
directives string points into memory that doesn't get destructed on LTO
compilation.
Test this by linking a bundled binary LTO object file, from an older
version of LLVM.
This fixes issue #78591, and downstream issue
https://github.com/mstorsjo/llvm-mingw/issues/392.
ARM64EC needs to handle both ARM and x86_64 exception tables. This is
achieved by separating their chunks and sorting them separately.
EXCEPTION_TABLE directory references x86_64 variant, while ARM variant
is exposed using CHPE metadata, which references
__arm64x_extra_rfe_table and __arm64x_extra_rfe_table_size symbols.
This patch relaxes the constraints on the error message saved in PDBInputFile when failing to load a pdb file.
Storing an `Error` member infers that it must be accessed exactly once, which doesn't fit in several scenarios:
- If an invalid PDB file is provided as input file but never used, a loading error is created but never handled, causing an assert at shutdown.
- PDB file created using MSVC's `/Zi` option : The loading error message must be displayed once per obj file.
Also, the state of `PDBInputFile` was altered when reading (taking) the `Error` member, causing issues:
- accessing it (taking the `Error`) makes the object look valid whereas it's not properly initialized
- read vs write concurrency on a same `PDBInputFile` in the ghash parallel algorithm
The solution adopted here was to instead store an optional error string, and generate Error objects from it on demand.
Differential Revision: https://reviews.llvm.org/D140333
CodeView doesn't have the ability to represent variables
in other ways than as in registers or memory values, but
LLVM very often transforms simple values into constants,
consider this program:
int f () { int i = 123; return i; }
LLVM will transform `i` into a constant value and just
leave behind a llvm.dbg.value, this can't be represented
as a S_LOCAL record in CodeView. But we can represent it
as a S_CONSTANT record.
This patch checks if the location of a debug value is null,
then we will insert a S_CONSTANT record instead of a S_LOCAL
value with the flag "OptimizedAway".
In lld we then output the S_CONSTANT in the right scope, before
they where always inserted in the global stream, now we check
the scope before inserting it.
This has shown to improve debugging for our developers
internally.
Fixes to llvm/llvm-project#55958
Reviewed By: aganea
Differential Revision: https://reviews.llvm.org/D138995
LLVM bitcode contains support for weak symbols, so we can add support
for overriding weak symbols in the output COFF even though COFF doesn't
have inherent support for weak symbols.
The motivation for this patch is that Chromium is trying to use libc++'s
assertion handler mechanism, which relies on weak symbols [0], but we're
unable to perform a ThinLTO build on Windows due to this problem [1].
[0]: https://reviews.llvm.org/D121478
[1]: https://crrev.com/c/3863576
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D133165
With D26647, we can already identify input object files compiled by cl.exe with
/GL. It seems to be helpful to do the same and print an error message for those
object files compiled with /GL but are inside libraries/archives too.
Reviewed By: rnk, thieta
Differential Revision: https://reviews.llvm.org/D131458
Microsoft shipped a bunch of PDB files with broken/invalid GUIDs
which lead lld to use 0xFF as the key for these files in an internal
cache. When multiple files have this key it will lead to collisions
and confused symbol lookup.
Several approaches to fix this was considered. Including making the key
the path to the PDB file, but this requires some filesystem operations
in order to normalize the file path.
Since this only happens with malformatted PDB files and we haven't
seen this before they malformatted files where shipped with visual
studio we probably shouldn't optimize for this use-case.
Instead we now just don't insert files with Guid == 0xFF into the
cache map and warn if we get collisions so similar problems can be
found in the future instead of being silent.
Discussion about the root issue and the approach to this fix can be found on Github: https://github.com/llvm/llvm-project/issues/54487
Reviewed By: aganea
Differential Revision: https://reviews.llvm.org/D122372
This patch writes the full -cc1 command into the resulting .OBJ, like MSVC does. This allows for external tools (Recode, Live++) to rebuild a source file without any external dependency but the .OBJ itself (other than the compiler) and without knowledge of the build system.
The LF_BUILDINFO record stores a full path to the compiler, the PWD (CWD at program startup), a relative or absolute path to the source, and the full CC1 command line. The stored command line is self-standing (does not depend on the environment). In the same way, MSVC doesn't exactly store the provided command-line, but an expanded version (a somehow equivalent of CC1) which is also self-standing.
For more information see PR36198 and D43002.
Differential Revision: https://reviews.llvm.org/D80833
D46245 added support for this in llvm-libtool, but while lld-link can
also create .lib files from .def files it didn't support aliases.
I compared the Inputs/library.def test against the output from
llvm-libtool and it matches, except for the fact that lld-link reorders
functions for some reason.
I have also verified that this fixes a bug I was running into while
trying to compile .def files to .lib files in MinGW-w64 (using lld-link
instead of llvm-libtool).
Differential Revision: https://reviews.llvm.org/D113365
If multiple /manifestdependency: flags are passed, they are
naively deduped, but after that each of them should have an
effect, instead of just the last one.
Also, /manifestdependency: flags are allowed in .drectve sections
(from `#pragma comment(linker, ...`). To make the interaction between
/manifestdependency: flags enabling manifest by default but
/manifest:no overriding this work, add an explict ManifestKind::Default
state to represent no explicit /manifest flag being passed.
To make /manifestdependency: flags from input file .drectve sections
work with /manifest:embed, delay embedded manifest emission until
after input files have been read.
Differential Revision: https://reviews.llvm.org/D108628
When enable CSPGO for ThinLTO, there are profile cfg mismatch warnings that will cause lld-link errors (with /WX).
To disable it we have to use an internal "/mllvm:-no-pgo-warn-mismatch" option.
In contrast clang uses option ”-Wno-backend-plugin“ to avoid such warnings and gcc has an explicit "-Wno-coverage-mismatch" option.
Add this "lto-pgo-warn-mismatch" option to lld to help turn on/off the profile mismatch warnings explicitly when build with ThinLTO and CSPGO.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D104431
The relocation offsets were incorrect. I fixed them with llvm-readobj
-codeview -codeview-subsection-bytes, which has a helpful printout of
the relocations that apply to a given symbol record with their offsets.
With this, I was able to update the relocation offsets in the yaml to
fix the line table and the S_DEFRANGE_REGISTER records.
There is still some remaining inconsistency in yaml2obj and obj2yaml
when round tripping MSVC objects, but that isn't a blocker for relanding
D94267.
Before this patch, when using LLD with /DEBUG:GHASH and MSVC precomp.OBJ files, we had a bunch of:
lld-link: warning: S_[GL]PROC32ID record in blabla.obj refers to PDB item index 0x206ED1 which is not a LF[M]FUNC_ID record
This was caused by LF_FUNC_ID and LF_MFUNC_ID which didn't have correct mapping to the corresponding TPI records. The root issue was that the indexMapStorage was improperly re-assembled in UsePrecompSource::remapTpiWithGHashes.
After this patch, /DEBUG and /DEBUG:GHASH produce exactly the same debug infos in the PDB.
Differential Revision: https://reviews.llvm.org/D93732
Before this patch /summary was crashing with some .PCH.OBJ files, because tpiMap[srcIdx++] was reading at the wrong location. When the TpiSource depends on a .PCH.OBJ file, the types should be offset by the previously merged PCH.OBJ set of indices.
Differential Revision: https://reviews.llvm.org/D88678
Binutils generated sections seem to be padded to a multiple of 16 bytes,
but the aux section definition contains the original, unpadded section
length.
The size check used for IMAGE_COMDAT_SELECT_SAME_SIZE previously
only checked the size of the section itself. When checking the
currently processed object file against the previously chosen
comdat section, we easily have access to the aux section definition
of the currently processed section, but we have to iterate over the
symbols of the previously selected object file to find the section
definition of the previously picked section. (We don't want to
inflate SectionChunk to carry more data, for something that is only
needed in corner cases.) Only do this when the mingw flag is set.
This fixes statically linking clang-built C++ object files against
libstdc++ built with GCC, if the object files contain e.g. typeinfo.
Differential Revision: https://reviews.llvm.org/D86659
This patch adds the missing information to the LF_BUILDINFO record, which allows for rebuilding a .CPP without any external dependency but the .OBJ itself (other than the compiler).
Some external tools that we are using (Recode, Live++) are extracting the information to reproduce a build without any knowledge of the build system. The LF_BUILDINFO stores a full path to the compiler, the PWD (CWD at program startup), a relative or absolute path to the TU, and the full CC1 command line. The command line needs to be freestanding (not depend on any environment variables). In the same way, MSVC doesn't store the provided command-line, but an expanded version (somehow their equivalent of CC1) which is also freestanding.
For more information see PR36198 and D43002.
Differential Revision: https://reviews.llvm.org/D80833
The "undefined symbol" error message from lld-link displays up to 3 references to that symbol, and the number of extra references not shown.
This patch removes the computation of the strings for those extra references.
It fixes a freeze of lld-link we accidentally encountered when activating asan on a large project, without linking with the asan library.
In that case, __asan_report_load8 was referenced more than 2 million times, causing the computation of that many display strings, of which only 3 were used.
Differential Revision: https://reviews.llvm.org/D83510
This patch adds some missing information to the LF_BUILDINFO which allows for rebuilding an .OBJ without any external dependency but the .OBJ itself (other than the compiler executable).
Some tools need this information to reproduce a build without any knowledge of the build system. The LF_BUILDINFO therefore stores a full path to the compiler, the PWD (which is the CWD at program startup), a relative or absolute path to the TU, and the full CC1 command line. The command line needs to be freestanding (not depend on any environment variable). In the same way, MSVC doesn't store the provided command-line, but an expanded version (somehow their equivalent of CC1) which is also freestanding.
For more information see PR36198 and D43002.
Differential Revision: https://reviews.llvm.org/D80833
This patch adds some missing information to the LF_BUILDINFO which allows for rebuilding an .OBJ without any external dependency but the .OBJ itself (other than the compiler executable).
Some tools need this information to reproduce a build without any knowledge of the build system. The LF_BUILDINFO therefore stores a full path to the compiler, the PWD (which is the CWD at program startup), a relative or absolute path to the TU, and the full CC1 command line. The command line needs to be freestanding (not depend on any environment variable). In the same way, MSVC doesn't store the provided command-line, but an expanded version (somehow their equivalent of CC1) which is also freestanding.
For more information see PR36198 and D43002.
Differential Revision: https://reviews.llvm.org/D80833
Before this patch, the debug record S_GTHREAD32 which represents global thread_local symbols, was emitted by LLD into the respective module stream. This makes Visual Studio unable to display thread_local symbols in the debugger.
After this patch, S_GTHREAD32 is moved into the globals stream. This matches MSVC behavior.
Differential Revision: https://reviews.llvm.org/D79005
Summary:
/PDBSTREAM:<name>=<file> adds the contents of <file> to stream <name> in the resulting PDB.
This allows native uses with workflows that (for example) add srcsrv streams to PDB files to provide a location for the build's source files.
Results should be equivalent to linking with lld-link, then running Microsoft's pdbstr tool with the command line:
pdbstr.exe -w -p:<PDB LOCATION> -s:<name> -i:<file>
except in cases where the named stream overlaps with a default named stream, such as "/names". In those cases, the added stream will be overridden, making the /pdbstream option a no-op.
Reviewers: thakis, rnk
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D77310
Added support for /map and /map:[filepath].
The output was derived from Microsoft's Link.exe output when using that same option.
Note that /MAPINFO support was not added.
The previous implementation of MapFile.cpp/.h was meant for /lldmap, and was renamed to LLDMapFile.cpp/.h
MapFile.cpp/.h is now for /MAP
However, a small fix was added to lldmap, replacing a std::sort with std::stable_sort to enforce reproducibility.
Differential Revision: https://reviews.llvm.org/D70557
A common pattern in Windows is to have all your precompiled headers
use an object named stdafx.obj. If you've got a project with many
different static libs, you might use a separate PCH for each one of
these.
During the final link step, a file from A might reference the PCH
object from A, but it will have the same name (stdafx.obj) as any
other PCH from another project. The only difference will be the
path. For example, A might be A/stdafx.obj while B is B/stdafx.obj.
The existing algorithm checks only the filename that was passed on
the command line (or stored in archive), but this is insufficient in
the case where relative paths are used, because depending on the
command line object file / library order, it might find the wrong
PCH object first resulting in a signature mismatch.
The fix here is to simply check whether the absolute path of the
PCH object (which is stored in the input obj file for the file that
references the PCH) *ends with* the full relative path of whatever
is specified on the command line (or is in the archive).
Differential Revision: https://reviews.llvm.org/D66431
llvm-svn: 374442
Fixes assert in addLinkerModuleCoffGroup() when using by-ordinal imports
only.
Patch by Stefan Schmidt.
Differential revision: https://reviews.llvm.org/D68352
llvm-svn: 374140
In mingw environments, resources are normally compiled to resource
object files directly, instead of letting the linker convert them to
COFF format.
Since some time, GCC supports the notion of a default manifest object.
When invoking the linker, GCC looks for the default manifest object
file, and if found in the expected path, it is added to linker commands.
The default manifest is one that indicates support for the latest known
versions of windows, to implicitly unlock the modern behaviours of certain
APIs.
Not all mingw/gcc distributions include this file, but e.g. in msys2,
the default manifest object is distributed in a separate package (which
can be but might not always be installed).
This means that even if user projects only use one single resource
object file, the linker can end up with two resource object files,
and thus needs to support merging them.
The default manifest has a language id of zero, and GNU ld has got
logic for dropping a manifest with a zero language id, if there's
another manifest present with a nonzero language id. If there are
multiple manifests with a nonzero language id, the merging process
errors out.
Differential Revision: https://reviews.llvm.org/D66825
llvm-svn: 370974
Summary:
This is a re-land of r370487 with a fix for the use-after-free bug
that rev contained.
This implements -start-lib and -end-lib flags for lld-link, analogous
to the similarly named options in ld.lld. Object files after
-start-lib are included in the link only when needed to resolve
undefined symbols. The -end-lib flag goes back to the normal behavior
of always including object files in the link. This mimics the
semantics of static libraries, but without needing to actually create
the archive file.
Reviewers: ruiu, smeenai, MaskRay
Reviewed By: ruiu, MaskRay
Subscribers: akhuang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66848
llvm-svn: 370816
Summary:
This implements -start-lib and -end-lib flags for lld-link, analogous
to the similarly named options in ld.lld. Object files after
-start-lib are included in the link only when needed to resolve
undefined symbols. The -end-lib flag goes back to the normal behavior
of always including object files in the link. This mimics the
semantics of static libraries, but without needing to actually create
the archive file.
Reviewers: ruiu, smeenai, MaskRay
Reviewed By: ruiu, MaskRay
Subscribers: akhuang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66848
llvm-svn: 370487
Extend WindowsResourceParser to support using a ResourceSectionRef for
loading resources from an object file.
Only allow merging resource object files in mingw mode; keep the
existing error on multiple resource objects in link mode.
If there only is one resource object file and no .res resources,
don't parse and recreate the .rsrc section, but just link it in without
inspecting it. This allows users to produce any .rsrc section (outside
of what the parser supports), just like before. (I don't have a specific
need for this, but it reduces the risk of this new feature.)
Separate out the .rsrc section chunks in InputFiles.cpp, and only include
them in the list of section chunks to link if we've determined that there
only was one single resource object. (We need to keep other chunks from
those object files, as they can legitimately contain other sections as
well, in addition to .rsrc section chunks.)
Differential Revision: https://reviews.llvm.org/D66824
llvm-svn: 370436
This avoids a spurious and confusing log message in cases where
both e.g. "alias" and "__imp_alias" exist.
Differential Revision: https://reviews.llvm.org/D65598
llvm-svn: 367673
