Patch by Thomas Roughton.
This patch adds support for linking with multiple definitions to LLD's
COFF driver, in line with link.exe's /force:multiple option.
Differential Revision: https://reviews.llvm.org/D50598
llvm-svn: 342191
This patch changes relative path for source files in obj files to
absolute path in PDB when linking with added flag.
I will make obj file generated by clang-cl independent from build
directory for chromium build. But I don't want to confuse visual studio
debugger or require additional configuration. To attain this goal, I
added flag to convert relative source file path in obj to absolute path
when emitting PDB.
By removing absolute path from obj files, we can share build cache
between chromium developers even when they are doing debug build.
That will make build time faster.
More context:
https://bugs.chromium.org/p/chromium/issues/detail?id=712796https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/5HXSVX-7fPc
llvm-svn: 337439
With this set, we retain the symbol table, but skip the actual debug
information.
This is meant to be used by the MinGW frontend.
Differential Revision: https://reviews.llvm.org/D48745
llvm-svn: 335946
- Move some common code into Common/rrorHandler.cpp and
Common/Strings.h.
- Don't use `fatal` when incompatible bitcode files are
encountered.
- Rename NameRef variable to just Name
See D47162
Differential Revision: https://reviews.llvm.org/D47206
llvm-svn: 333021
Previously we would always write a hash of the binary into the
PE file, for reproducible builds. This breaks AppCompat, which
is a feature of Windows that relies on the timestamp in the PE
header being set to a real value (or at the very least, a value
that satisfies certain properties).
To address this, we put the old behavior of writing the hash
behind the /Brepro flag, which mimics MSVC linker behavior. We
also match MSVC default behavior, which is to write an actual
timestamp to the PE header. Finally, we add the /TIMESTAMP
option (an lld extension) so that the user can specify the exact
value to be used in case he/she manually constructs a value which
is both reproducible and satisfies AppCompat.
Differential Revision: https://reviews.llvm.org/D46966
llvm-svn: 332613
We discovered (crbug.com/838449#c24) that string tail merging can
negatively affect compressed binary size, so provide a flag to turn
it off for users who care more about compressed size than uncompressed
size.
Differential Revision: https://reviews.llvm.org/D46780
llvm-svn: 332149
I needed to revert r330223 because we were embedding an absolute PDB
path in the .rdata section, which ended up being laid out before the
.idata section and affecting its RVAs. This flag will let us control
the embedded path.
Differential Revision: https://reviews.llvm.org/D45747
llvm-svn: 330232
This was reverted several times due to what ultimately turned out
to be incompatibilities in our serialized hash table format.
Several changes went in prior to this to fix those issues since
they were more fundamental and independent of supporting injected
sources, so now that those are fixed this change should hopefully
pass.
llvm-svn: 328363
This is still failing on a different bot this time due to some
issue related to hashing absolute paths. Reverting until I can
figure it out.
llvm-svn: 328014
The issue causing this to fail in certain configurations
should be fixed.
It was due to the fact that DIA apparently expects there to be
a null string at ID 1 in the string table. I'm not sure why this
is important but it seems to make a difference, so set it.
llvm-svn: 328002
Natvis is a debug language supported by Visual Studio for
specifying custom visualizers. The /NATVIS option is an
undocumented link.exe flag which will take a .natvis file
and "inject" it into the PDB. This way, you can ship the
debug visualizers for a program along with the PDB, which
is very useful for postmortem debugging.
This is implemented by adding a new "named stream" to the
PDB with a special name of /src/files/<natvis file name>
and simply copying the contents of the xml into this file.
Additionally, we need to emit a single stream named
/src/headerblock which contains a hash table of embedded
files to records describing them.
This patch adds this functionality, including the /NATVIS
option to lld-link.
Differential Revision: https://reviews.llvm.org/D44328
llvm-svn: 327895
GNU ld has got a number of different flags for adjusting how to
behave around stdcall functions. The --kill-at flag strips the
trailing sdcall suffix from exported functions (which otherwise
is included by default in MinGW setups).
This also strips it from the corresponding import library though.
That makes it hard to link to such an import library from code
that calls the functions - but this matches what GNU ld does with
this flag. Therefore, this flag is probably not sensibly used
together with import libraries, but probably mostly when creating
some sort of plugin, or if creating the import library separately
with dlltool.
Differential Revision: https://reviews.llvm.org/D44292
llvm-svn: 327561
Summary:
This protects calls to longjmp from transferring control to arbitrary
program points. Instead, longjmp calls are limited to the set of
registered setjmp return addresses.
This also implements /guard:nolongjmp to allow users to link in object
files that call setjmp that weren't compiled with /guard:cf. In this
case, the linker will approximate the set of address taken functions,
but it will leave longjmp unprotected.
I used the following program to test, compiling it with different -guard
flags:
$ cl -c t.c -guard:cf
$ lld-link t.obj -guard:cf
#include <setjmp.h>
#include <stdio.h>
jmp_buf buf;
void g() {
printf("before longjmp\n");
fflush(stdout);
longjmp(buf, 1);
}
void f() {
if (setjmp(buf)) {
printf("setjmp returned non-zero\n");
return;
}
g();
}
int main() {
f();
printf("hello world\n");
}
In particular, the program aborts when the code is compiled *without*
-guard:cf and linked with -guard:cf. That indicates that longjmps are
protected.
Reviewers: ruiu, inglorion, amccarth
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43217
llvm-svn: 325047
Summary:
This patch adds some initial support for Windows control flow guard. At
the end of the day, the linker needs to synthesize a table of RVAs very
similar to the structured exception handler table (/safeseh).
Both /safeseh and /guard:cf take sections of symbol table indices
(.sxdata and .gfids$y) and turn them into RVA tables referenced by the
load config struct in the CRT through special symbols.
Reviewers: ruiu, amccarth
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42592
llvm-svn: 324306
Summary:
r323164 made lld-link not overwrite import libraries when their
contents haven't changed. MSVC's link.exe does this only when
performing incremental linking. This change makes lld-link's import
library overwriting similarly dependent on whether or not incremental
linking is being performed. This is controlled by the /incremental or
/incremental:no options. In addition, /opt:icf, /opt:ref, and /order
turn off /incremental and issue a warning if /incremental was
specified on the command line.
Reviewers: rnk, ruiu, zturner
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42716
llvm-svn: 323930
With the /order option, you can give an order file. An order file
contains symbol names, one per line, and the linker places comdat
sections in that given order. The option is used often to optimize
an output binary for (in particular, startup) speed by improving
locality.
Differential Revision: https://reviews.llvm.org/D42598
llvm-svn: 323579
The classes used to print and update time information are in
common, so other linkers could use this as well if desired.
Differential Revision: https://reviews.llvm.org/D41915
llvm-svn: 322736
It was being set but never used, and its value is only ever needed
locally in lld::coff::link.
Differential Revision: https://reviews.llvm.org/D41814
llvm-svn: 322026
Summary:
lld-link accepts link.exe's /ignore option, but used to ignore
it. This can lead to semantic differences when warnings are treated as
fatal errors. One such case is when we resolve an __imp_ symbol to a
local definition. We emit a warning in that case, which /wx turns into
a fatal. This change makes lld-link accept /ignore:4217 to suppress
that warning, so that code that links with link.exe /wx /ignore:4217
links with lld-link, too.
Fixes PR35762.
Reviewers: rnk, ruiu
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41606
llvm-svn: 321512
This adds the /DEBUG:GHASH option to LLD which will look for
the existence of .debug$H sections in linker inputs and use them
to accelerate type merging. The clang-cl side has already been
added, so this completes the work necessary to begin experimenting
with this feature.
Differential Revision: https://reviews.llvm.org/D40980
llvm-svn: 320719
This effectively reverts r318548 and r318635 while keeping the
functionality behind the flag and preserving the bug fix from r318548.
Differential Revision: https://reviews.llvm.org/D40264
llvm-svn: 318721
For GC roots, add a bit to SymbolBody to ensure that we don't add the
same root twice, and switch to a vector. In addition to being faster,
this may also fix some latent non-determinism. We iterate the GCRoot
list later and it the order should be deterministic.
For fixupExports, we can just use DenseMap. This is a simple string
uniquing task, and we don't iterate the map.
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39609
llvm-svn: 318072
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
link.exe supports this option to convert warnings into errors, and it's
useful to support in LLD as well.
Differential Revision: https://reviews.llvm.org/D39148
llvm-svn: 316502
Previously, the COFF driver would call exit(0) when called
as a library. Now it takes `ExitEarly` option, and if it
is false, it doesn't exit. So it is now more library-friendly.
Furthermore, link() calls freeArena() before returning, to
clean up resources.
Based on an Andrew Kelley's patch.
Differential Revision: https://reviews.llvm.org/D39202
llvm-svn: 316370
r303378 was submitted because r303374 (Merge IAT and ILT) made lld's
output incompatible with the Binding feature. Now that r303374 was
reverted, we do not need to keep this change.
Pointed out by pcc.
llvm-svn: 313414
In MinGW configurations (GCC, or clang with a *-windows-gnu target),
the -export directives in the object file contains the undecorated
symbol name, while it is decorated in MSVC configurations. (On the
command line, link.exe takes an undecorated symbol name for the
-export argument though.)
Differential Revision: https://reviews.llvm.org/D37772
llvm-svn: 313174
These are emitted for comm symbols in object files, when targeting
a GNU environment.
Alternatively, just ignore them since we already align CommonChunk
to the natural size of the content (up to 32 bytes). That would only
trade away the possibility to overalign small symbols, which doesn't
sound like something that might not need to be handled?
Differential Revision: https://reviews.llvm.org/D36304
llvm-svn: 310871
Also emit an error if /manifestinput: is used without /manifest:embed.
Increases compatibility with link.exe
https://reviews.llvm.org/D35842
llvm-svn: 308998
Improve the link conformance for the import name embedded into the
import library. This requires the associated change to the LLVM portion
for the DEF file parser. The import file generation embeds a different
name based on whether the driver is invoked as "link" or "lib".
Furthermore, the LIBRARY keyword in the DEF file influences the import
name. The behaviour can be summarised according to the following table:
| LIBRARY w/ ext | LIBRARY w/o ext | no LIBRARY
-----+----------------+---------------------+------------------
LINK | {value} | {value}.{.dll/.exe} | {output name}
LIB | {value} | {value}.dll | {output name}.dll
llvm-svn: 308407
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
Our output is not compatible with the Binding feature, so make it
explicit that.
Differential Revision: https://reviews.llvm.org/D33336
llvm-svn: 303378
When /DEBUG is not specified, /PDB should be ignored. When
/DEBUG is specified, a PDB should be output regardless of
whether or not /PDB is specified. /PDB just overrides the
default name.
This patch implements this behavior, and adds some tests, while
also removing a dead option /DEBUGPDB which was unused in any
code.
Differential Revision: https://reviews.llvm.org/D33302
llvm-svn: 303352
The CONSTANT export type is marked as obsolete, but link still supports
this. Furthermore, WinObjC uses this for certain exports. Add support
for this export type.
llvm-svn: 301013
Summary:
lld-link allows the number of parallel ThinLTO jobs to be specified
using /opt:lldltojobs=N. If left unspecified, the implementation
conservatively defaults to 1. This leads to very long link times. This
change makes it so that the default is to automatically set the
parallelism, as we do in the ELF linker.
Reviewers: ruiu, hans
Reviewed By: ruiu, hans
Subscribers: pcc, mehdi_amini, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D31986
llvm-svn: 300089
The /appcontainer flag indicates that the module may only be used inside
an application container (for isolation). This has been supported by
link.exe since Windows 8.0. It sets an additional bit in the PE DLL
Characteristics flag to indicate the behavioural change.
llvm-svn: 299728
Summary: This adds an option to save temporary files generated during link-time optimization. This can be useful for debugging.
Reviewers: ruiu, pcc
Reviewed By: ruiu, pcc
Subscribers: mehdi_amini
Differential Revision: https://reviews.llvm.org/D29518
llvm-svn: 294498
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
Summary: This copies over some functionality we have in ELF/Error.{cpp,h} and makes it available in COFF/Error.{cpp,h}
Reviewers: pcc, rafael, ruiu
Subscribers:
Differential Revision: https://reviews.llvm.org/D28692
llvm-svn: 292240
Rui Ueyama