Now that we have only SymbolBody as the symbol class. So, "SymbolBody"
is a bit strange name now. This is a mechanical change generated by
perl -i -pe s/SymbolBody/Symbol/g $(git grep -l SymbolBody lld/ELF lld/COFF)
nd clang-format-diff.
Differential Revision: https://reviews.llvm.org/D39459
llvm-svn: 317370
Summary:
The COFF linker and the ELF linker have long had similar but separate
Error.h and Error.cpp files to implement error handling. This change
introduces new error handling code in Common/ErrorHandler.h, changes the
COFF and ELF linkers to use it, and removes the old, separate
implementations.
Reviewers: ruiu
Reviewed By: ruiu
Subscribers: smeenai, jyknight, emaste, sdardis, nemanjai, nhaehnle, mgorny, javed.absar, kbarton, fedor.sergeev, llvm-commits
Differential Revision: https://reviews.llvm.org/D39259
llvm-svn: 316624
Apply the simplification suggestions that Peter Collingbourne made
during the review at D37368. The returned thunk is cast to the
appropriate type in the SymbolTable, and the constant symbol's body is
not needed directly, so avoid the assignment. NFC
llvm-svn: 312391
If a symbol is locally defined and is DLL imported in another
translation unit, and the object with the locally defined version is
loaded prior to the imported version, then the linker will fail to
resolve the definition of the thunk and return the locally defined
symbol. This will then be attempted to be cast to an import thunk,
which will clearly fail.
Only return the thunk if the symbol is inserted or a thunk is created.
Otherwise, report a duplication error.
llvm-svn: 312386
This reverts commit r312171 because it is pointed out that that's not a
correct fix (see https://bugs.llvm.org/show_bug.cgi?id=32674#c14) and
also because it broke buildbots.
llvm-svn: 312174
MSVC link.exe supports nested static libraries. That is, an .a file can
contain other .a file as its member. It is reported that MySQL actually
depends on this feature.
Fixes https://bugs.llvm.org/show_bug.cgi?id=32674
llvm-svn: 312171
A plain empty entry point function that returns 0 seems to produce
a binary that loads and runs fine in wine.
Differential Revision: https://reviews.llvm.org/D34833
llvm-svn: 306963
Summary:
Previously we didn't add debug info chunks to the SparseChunks array, so
they didn't participate in section GC. Now we do.
Reviewers: ruiu
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D34356
llvm-svn: 305811
Summary:
Adds a "Discarded" bool to SectionChunk to indicate if the section was
discarded by COMDAT deduplication. The Writer still just checks
`isLive()`.
Fixes PR33446
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34288
llvm-svn: 305582
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
This reverts commit r303304 because it looks like the change
introduced a crash bug. At least after that change, LLD with thinlto
crashes when linking Chromium.
llvm-svn: 303527
We've been using make<> to allocate new objects in ELF. We have
the same function in COFF, but we didn't use it widely due to
negligence. This patch uses the function in COFF to close the gap
between ELF and COFF.
llvm-svn: 303357
This reverts re-submits r303225 which was reverted in r303270 because it
broke the sanitizer-windows bot.
The reason of the failure is that we were writing dead symbols to the
symbol table. I fixed the issue.
llvm-svn: 303304
and follow-up r303226 "Fix Windows buildbots."
This broke the sanitizer-windows buildbot.
> Previously, the garbage collector (enabled by default or by explicitly
> passing /opt:ref) did not kill dllimported symbols. As a result,
> dllimported symbols could be added to resulting executables' dllimport
> list even if no one was actually using them.
>
> This patch implements dllexported symbol garbage collection. Just like
> COMDAT sections, dllimported symbols now have Live bits to manage their
> liveness, and MarkLive marks reachable dllimported symbols.
>
> Fixes https://bugs.llvm.org/show_bug.cgi?id=32950
>
> Reviewers: pcc
>
> Subscribers: llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D33264
llvm-svn: 303270
Summary:
Previously, the garbage collector (enabled by default or by explicitly
passing /opt:ref) did not kill dllimported symbols. As a result,
dllimported symbols could be added to resulting executables' dllimport
list even if no one was actually using them.
This patch implements dllexported symbol garbage collection. Just like
COMDAT sections, dllimported symbols now have Live bits to manage their
liveness, and MarkLive marks reachable dllimported symbols.
Fixes https://bugs.llvm.org/show_bug.cgi?id=32950
Reviewers: pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33264
llvm-svn: 303225
CONSTANT imports expect both the `_imp_` prefixed and non-prefixed
symbols should be added to the symbol table. This allows for linking
symbols like _NSConcreteGlobalBlock in WinObjC. The previous change
would generate the import library properly by handling the option but
would not consume the generated entry properly.
llvm-svn: 301657
Start using it in LLD to avoid needing to read bitcode again just to get the
target triple, and in llvm-lto2 to avoid printing symbol table information
that is inappropriate for the target.
Differential Revision: https://reviews.llvm.org/D32038
llvm-svn: 300300
Introduce symbol table data structures that can be potentially written to
disk, have the LTO library build those data structures using temporarily
constructed modules and redirect the LTO library implementation to go through
those data structures. This allows us to remove the LLVMContext and Modules
owned by InputFile.
With this change I measured a peak memory consumption decrease from 5.4GB to
2.8GB in a no-op incremental ThinLTO link of Chromium on Linux. The impact on
memory consumption is larger in COFF linkers where we are currently forced
to materialize all metadata in order to read linker options. Peak memory
consumption linking a large piece of Chromium for Windows with full LTO and
debug info decreases from >64GB (OOM) to 15GB.
Part of PR27551.
Differential Revision: https://reviews.llvm.org/D31364
llvm-svn: 299168
Summary: In the ELF linker, we create the buffer identifier for bitcode files by appending the object name to the archive name. This change makes the COFF linker do the same. Without the change, ThinLTO builds can fail with an error message about multiple ThinLTO modules per object file, caused by object files contained in different archives having the same name.
Reviewers: pcc, ruiu
Reviewed By: pcc
Subscribers: mehdi_amini
Differential Revision: https://reviews.llvm.org/D31402
llvm-svn: 298942
Summary: The COFF linker previously implemented link-time optimization using an API which has now been marked as legacy. This change refactors the COFF linker to use the new LTO API, which is also used by the ELF linker.
Reviewers: pcc, ruiu
Reviewed By: pcc
Subscribers: mgorny, mehdi_amini
Differential Revision: https://reviews.llvm.org/D29059
llvm-svn: 293967
I thought for a while about how to remove it, but it looks like we
can just copy the file for now. Of course I'm not happy about that,
but it's just less than 50 lines of code, and we already have
duplicate code in Error.h and some other places. I want to solve
them all at once later.
Differential Revision: https://reviews.llvm.org/D27819
llvm-svn: 290062
Profiling revealed that the majority of lld's execution time on Windows was
spent opening and mapping input files. We can reduce this cost significantly
by performing these operations asynchronously.
This change introduces a queue for all operations on input file data. When
we discover that we need to load a file (for example, when we find a lazy
archive for an undefined symbol, or when we read a linker directive to
load a file from disk), the file operation is launched using a future and
the symbol resolution operation is enqueued. This implies another change
to symbol resolution semantics, but it seems to be harmless ("ninja All"
in Chromium still succeeds).
To measure the perf impact of this change I linked Chromium's chrome_child.dll
with both thin and fat archives.
Thin archives:
Before (median of 5 runs): 19.50s
After: 10.93s
Fat archives:
Before: 12.00s
After: 9.90s
On Linux I found that doing this asynchronously had a negative effect on
performance, probably because the cost of mapping a file is small enough that
it becomes outweighed by the cost of managing the futures. So on non-Windows
platforms I use the deferred execution strategy.
Differential Revision: https://reviews.llvm.org/D27768
llvm-svn: 289760
This ports the ELF linker's symbol table design, introduced in r268178,
to the COFF linker.
Differential Revision: http://reviews.llvm.org/D21166
llvm-svn: 289280
Profiling revealed that we were spending 5% of our time linking
chrome_child.dll just in this call to toString().
Differential Revision: https://reviews.llvm.org/D27628
llvm-svn: 289270
Previously, we had different way to stringize SymbolBody and InputFile
to construct error messages. This patch defines overloaded function
toString() so that we don't need to memorize all these different
function names.
With that change, it is now easy to include demangled names in error
messages. Now, if there is a symbol name conflict, we'll print out
both mangled and demangled names.
llvm-svn: 288992
Previously, we discarded .debug$ sections. This patch adds them to
files so that PDB.cpp can access them.
This patch also adds a debug option, /dumppdb, to dump debug info
fed to createPDB so that we can verify that valid data has been passed.
llvm-svn: 287555
This flag is implemented similarly to --reproduce in the ELF linker.
This patch implements /linkrepro by moving the cpio writer and associated
utility functions to lldCore, and using that implementation in both linkers.
One COFF-specific detail is that we store the object file from which the
resource files were created in our reproducer, rather than the resource
files themselves. This allows the reproducer to be used on non-Windows
systems for example.
Differential Revision: https://reviews.llvm.org/D22418
llvm-svn: 276719
With the llvm change in r265606 this is the matching needed change to the lld
code now that createBinary() is returning Expected<...> .
llvm-svn: 265607
LLD type-punned an integral type and a pointer type using a pointer
field. This is problematic because the pointer type has alignment
greater than some of the integral values.
This would be less problematic if a union was used but it turns out the
integral values are only present for a short, transient, amount of time.
Let's remove this undefined behavior by skipping the punning altogether
by storing the state in a separate memory location: a vector which
informs us which symbols to process for weak externs.
llvm-svn: 263918
This fixes a test which exposed an ASan issue.
We assumed that a symbol's section number had a corresponding section
without performing validation.
llvm-svn: 263558
Previously, we calculated our own hash values for section contents.
Of coruse that's slow because we had to access all bytes in sections.
Fortunately, COFF objects usually contain hash values for COMDAT
sections. We can use that to speed up Identical COMDAT Folding.
llvm-svn: 246869
This patch fixes a subtle incompatibility with MSVC linker.
MSVC linker preserves the original spelling of a DLL in the
import descriptor table. LLD previously converted all
characters to lowercase. Usually this difference is benign,
but if a program explicitly checks for DLL file names, the
program could fail.
llvm-svn: 246620
__NULL_IMPORT_DESCRIPTOR is a symbol used by MSVC liner to construct
the import descriptor table. We do not use the symbol. Previously,
we had code to skip that symbol. That code does not actually do
anything meaningful because no one is referencing the symbol, the
symbol would naturally be ignored. This patch stops recognizing
the symbol.
llvm-svn: 245280
Previously, weak external symbols could reference only symbols that
appeared before them. Although that covers almost all use cases
of weak externals, there are object files out there which contains
weak externals that have forward references.
This patch supports such weak externals.
llvm-svn: 245258
There are some DLLs whose initializers depends on other DLLs'
initializers. The initialization order matters for them.
MSVC linker uses the order of the libraries from the command line.
LLD used ASCII-betical order. So they were incompatible.
This patch makes LLD compatible with MSVC.
llvm-svn: 245201
This has a few advantages
* Less C++ code (about 300 lines less).
* Less machine code (about 14 KB of text on a linux x86_64 build).
* It is more debugger friendly. Just set a breakpoint on the exit function and
you get the complete lld stack trace of when the error was found.
* It is a more robust API. The errors are handled early and we don't get a
std::error_code hot potato being passed around.
* In most cases the error function in a better position to print diagnostics
(it has more context).
llvm-svn: 244215
Leaving them in an executable is basically harmless but wastes disk space.
Because no one is using non-DWARF debug info linked by LLD, we can just
remove them.
llvm-svn: 243364
An object file compatible with Safe SEH contains a .sxdata section.
The section contains a list of symbol table indices, each of which
is an exception handler function. A safe SEH-enabled executable
contains a list of exception handler RVAs. So, what the linker has
to do to support Safe SEH is basically to read the .sxdata section,
interpret the contents as a list of symbol indices, unique-fy and
sort their RVAs, and then emit that list to .rdata. This patch
implements that feature.
llvm-svn: 243182
I am adding support for thin archives. On those, getting the buffer
involves reading another file.
Since we only need an id in here, use the member offset in the archive.
llvm-svn: 242205
clang-cl doesn't compile std::atomic_flag correctly (PR24101). Since the COFF
linker doesn't use threads yet, just revert r241420 and r241481 for now to
work around this clang-cl bug.
llvm-svn: 242006
Previously, we infer machine type at the very end of linking after
all symbols are resolved. That's actually too late because machine
type affects how we mangle symbols (whether or not we need to
add "_").
For example, /entry:foo adds "_foo" to the symbol table if x86 but
"foo" if x64.
This patch moves the code to infer machine type, so that machine
type is inferred based on input files given via the command line
(but not based on .directives files).
llvm-svn: 241843
Symbols exported by DLLs are listed in import library files.
Exported names may be mangled by "Import Name Type" field as
described in PE/COFF spec 7.3. This patch implements that
mangling scheme.
llvm-svn: 241719
Providing a symbol table in the executable is quite useful when
debugging a fully-linked executable without having to reconstruct one
from DWARF.
Differential Revision: http://reviews.llvm.org/D11023
llvm-svn: 241689
The previous code was not even safe with MSVC 2013 because the compiler
doesn't guarantee that static variables (in this case, a mutex) are
initialized in a thread-safe manner.
llvm-svn: 241481
This function is called SymbolTable::readObjects, so in order to
parallelize that function, we have to make this function thread-safe.
llvm-svn: 241420
Rui Ueyama