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
Dwarf debug info contains some data that contains absolute addresses.
Since these sections are discardable and aren't loaded at runtime,
there's no point in adding base relocations for them.
This makes sure that after stripping out dwarf debug info, there are no
base relocations that point to nonexistent sections.
Differential Revision: https://reviews.llvm.org/D49350
llvm-svn: 337438
Some Microsoft tools (e.g. new versions of WPA) fail when the
COFF Debug Directory contains a path to the PDB that contains
dots, such as D:\foo\./bar.pdb. Remove dots before writing this
path.
This fixes pr38126.
llvm-svn: 336873
Future symbol insertions can potentially change the type of these
symbols - keep pointers to the base class to reflect this, and
use dynamic casts to inspect them before using as the subclass
type.
This fixes crashes that were possible before, by touching these
symbols that now are populated as e.g. a DefinedRegular, via
the old pointers with DefinedImportThunk type.
Differential Revision: https://reviews.llvm.org/D48953
llvm-svn: 336652
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
Summary:
Control flow guard works best when targets it checks are 16-byte aligned.
Microsoft's link.exe helps ensure this by aligning code from sections
that are referenced from the gfids table to 16 bytes when linking with
-guard:cf, even if the original section specifies a smaller alignment.
This change implements that behavior in lld-link.
See https://crbug.com/857012 for more details.
Reviewers: ruiu, hans, thakis, zturner
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48690
llvm-svn: 335864
`lld-link foo.lib /wholearchive:foo.lib` should work the same way as
`lld-link /wholearchive:foo.lib foo.lib`. Previously, /wholearchive in
the former case was ignored.
Differential Revision: https://reviews.llvm.org/D47565
llvm-svn: 334552
When running with linker GC (`-opt:ref`), defined imported symbols that
are referenced but then dropped by GC end up with their `Location`
member being nullptr, which means `getChunk()` returns nullptr for them
and attempting to call `getChunk()->getOutputSection()` causes a crash
from the nullptr dereference. Check for `getChunk()` being nullptr and
bail out early to avoid the crash.
Differential Revision: https://reviews.llvm.org/D48092
llvm-svn: 334548
This simplifies some code which had StringRefs to begin with, and
makes other code more complicated which had const char* to begin
with.
In the end, I think this makes for a more idiomatic and platform
agnostic API. Not all platforms launch process with null terminated
c-string arrays for the environment pointer and argv, but the api
was designed that way because it allowed easy pass-through for
posix-based platforms. There's a little additional overhead now
since on posix based platforms we'll be takign StringRefs which
were constructed from null terminated strings and then copying
them to null terminate them again, but from a readability and
usability standpoint of the API user, I think this API signature
is strictly better.
llvm-svn: 334518
Summary:
When reporting an unsupported relocation type, let's also report the
file we encountered it in to aid diagnosis.
Reviewers: ruiu, rnk
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45911
llvm-svn: 334154
Peter Collingbourne suggested moving the switch to the top of the
function, so that all the code that cares about the output section for a
symbol is in the same place.
Differential Revision: https://reviews.llvm.org/D47497
llvm-svn: 333472
Rather than using a loop to compare symbol RVAs to the starting RVAs of
sections to determine which section a symbol belongs to, just get the
output section of a symbol directly via its chunk, and bail if the
symbol doesn't have an output section, which avoids having to hardcode
logic for handling dead symbols, CodeView symbols, etc. This was
suggested by Reid Kleckner; thank you.
This also fixes writing out symbol tables in the presence of RVA table
input sections (e.g. .sxdata and .gfids). Such sections aren't written
to the output file directly, so their RVA is 0, and the loop would thus
fail to find an output section for them, resulting in a segfault. Extend
some existing tests to cover this case.
Fixes PR37584.
Differential Revision: https://reviews.llvm.org/D47391
llvm-svn: 333450
- 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 emitted 20-byte SHA1 hashes. This is overkill
for identifying debug info records, and has the negative side
effect of making object files bigger and links slower. By
using only the last 8 bytes of a SHA1, we get smaller object
files and ~10% faster links.
This modifies the format of the .debug$H section by adding a new
value for the hash algorithm field, so that the linker will still
work when its object files have an old format.
Differential Revision: https://reviews.llvm.org/D46855
llvm-svn: 332669
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
This is needed to avoid merging two functions with identical
instructions but different xdata. It also reduces binary size by
deduplicating identical pdata sections.
Fixes PR35337.
Differential Revision: https://reviews.llvm.org/D46672
llvm-svn: 332169
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
This is most useful when using lld-link on a non-Win host (but it might become
useful on Windows too if lld also grows a fansi-escape-codes flag).
Also make the help for --color-diagnostic mention the valid values in ELF and
wasm, and print the flag name with two dashes in diags, since the one-dash form
is seen as a list of many one-letter flags in some contexts.
https://reviews.llvm.org/D46693
llvm-svn: 332012
Previously this was only supported when specified on the command line
or in directives.
Differential Revision: https://reviews.llvm.org/D46244
llvm-svn: 331900
The operator == used for exporting a function with a different
name in the DLL compared to the name in the import library
(which is useful for adding linker level aliases for function
in the import library) is a feature distinct and different from
the operator = used for exporting a function with a different
name (both in import library and DLL) than in the implementation
producing the DLL.
When creating an import library using dlltool, from a def file that
contains forwards (Func = OtherDll.Func), this shouldn't affect the
produced import library, which should still behave just as if it
was a normal exported function.
This clears a lot of confusion and subtle misunderstandings, and
avoids a parameter that was used to avoid creating weak aliases
when invoked from lld. (This parameter was added previously due to
the existing conflation of the two features.)
Differential Revision: https://reviews.llvm.org/D46245
llvm-svn: 331860
Now only IMAGE_REL_ARM64_ABSOLUTE and IMAGE_REL_ARM64_TOKEN
are unhandled.
Also add range checks for the existing BRANCH26 relocation.
Differential Revision: https://reviews.llvm.org/D46354
llvm-svn: 331505
Summary:
When a symbol refers to a special section or a section that doesn't
exist, lld would fatal with "broken object file". This change gives a
different message for each scenario, and includes the name of the
file, name of the symbol, and the section being referred to.
Reviewers: pcc, ruiu
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46090
llvm-svn: 330883
Summary:
In a number of places in the COFF linker, we were calling
MemoryBuffer::getFile() with default parameters. This causes LLVM to
NUL-terminate the buffers, which can prevent them from being memory
mapped. Since we operate on binary and do not use NUL as an indicator
of the end of the file content, this change causes us to not require
the NUL terminator anymore.
Reviewers: ruiu, pcc
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45909
llvm-svn: 330786
With MSVC linker, /DEBUG is an alias of /DEBUG:FASTLINK, and if
you don't want /DEBUG:FASTLINK you have to explicitly specify
/DEBUG:FULL.
LLD doesn't support /DEBUG:FASTLINK, and so our standard /DEBUG
option is what MSVC calls /DEBUG:FULL. To provide command line
compatibility with MSVC, we should also support /DEBUG:FULL, and
since it's the same as what LLD already does for /DEBUG, just
alias it.
llvm-svn: 330647
Summary:
ubsan found that we sometimes pass nullptr to memcpy in
SectionChunk::writeTo(). This change adds a check that avoids that.
Reviewers: ruiu
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45789
llvm-svn: 330490
This is what link.exe does and lets us avoid needing to worry about
merging output characteristics while adding input sections to output
sections.
With this change we can't process /merge in the same way as before
because sections with different output characteristics can still
be merged into one another. So this change moves the processing of
/merge to just before we assign addresses. In the case where there
are multiple output sections with the same name, link.exe only merges
the first section with the source name into the first section with
the target name, and we do the same.
At the same time I also implemented transitive merging (which means
that /merge:.c=.b /merge:.b=.a merges both .c and .b into .a).
This isn't quite enough though because link.exe has a special case for
.CRT in 32-bit mode: it processes sections whose output characteristics
are DATA | R | W as though the output characteristics were DATA | R
(so that they get merged into things like constructor lists in the
expected way). Chromium has a few such sections, and it turns out
that those sections were causing the problem that resulted in r318699
(merge .xdata into .rdata) being reverted: because of the previous
permission merging semantics, the .CRT sections were causing the entire
.rdata section to become writable, which caused the SEH runtime to
crash because it apparently requires .xdata to be read-only. This
change also implements the same special case.
This should unblock being able to merge .xdata into .rdata by default,
as well as .bss into .data, both of which will be done in followups.
Differential Revision: https://reviews.llvm.org/D45801
llvm-svn: 330479
It's possible to have an empty object file, for example if you
just compile an empty .c file. This file won't have any sections
so asserting that a file has chunks is definitely wrong.
llvm-svn: 330461
Part of the DBI stream is a list of variable length structures
describing each module that contributes to the final executable.
One member of this structure is a section contribution entry that
describes the first section contribution in the output file for
the given module.
We have been leaving this structure unpopulated until now, so with
this patch it is now filled out correctly.
Differential Revision: https://reviews.llvm.org/D45832
llvm-svn: 330457
In an upcoming change I will need to make a distinction between section
type (code, data, bss) and permissions. The term that I use for both
of these things is "output characteristics".
Differential Revision: https://reviews.llvm.org/D45799
llvm-svn: 330361
Summary:
DLLs and executables with no exception handlers need to be marked with
IMAGE_DLL_CHARACTERISTICS_NO_SEH, even if they have a load config.
Discovered here when building Chromium with LLD on Windows:
https://crbug.com/833951
Reviewers: ruiu, mstorsjo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45778
llvm-svn: 330300
Summary:
This change does three things:
- Try to find the file and line number of an undefined symbol
reference by reading codeview debug info.
- Try to find the name of the function or global variable with the
undefined symbol reference by searching the object file's symbol
table.
- Prints the information in the same style as the ELF linker.
Differential Revision: https://reviews.llvm.org/D45467
llvm-svn: 330235
In this reland I removed an unnecessary use of /debug in the test
delayimports32.test and used the /pdbaltpath flag in the test
pdb-publics-import.test, both of which avoid embedding absolute PDB
paths in executables which could affect later RVAs.
Original commit message:
> COFF: Merge .idata, .didat and .edata into .rdata by default.
>
> This saves a little space and matches what link.exe does.
>
> Tested using the chromium Windows trybots:
> https://chromium-review.googlesource.com/c/chromium/src/+/1014784
Differential Revision: https://reviews.llvm.org/D45737
llvm-svn: 330233
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
Using Config->is64() will treat ARM64 as Amd64, which is incorrect.
Furthermore, there are more esoteric architectures that could
theoretically be encountered. Just set it directly to the machine
type, which we already know anyway.
llvm-svn: 330157
Most of these are pretty trivial and obvious. Setting the toolchain
version to 14.11 is perhaps a little questionable, but we've been bitten
in the past where one of our version fields sidn't match MSVC's, and I
definitely don't want to go through that diagnosis again as it was
pretty time consuming and hard to track down.
I found all of these by using llvm-pdbutil export to dump the dbi and
pdb streams to a file, then using fc followed by llvm-pdbutil explain to
explain the mismatched bytes.
There are still some more, these are just the low hanging fruit.
Differential Revision: https://reviews.llvm.org/D45276
llvm-svn: 330130
LLVM_ON_WIN32 is set exactly with MSVC and MinGW (but not Cygwin) in
HandleLLVMOptions.cmake, which is where _WIN32 defined too. Just use the
default macro instead of a reinvented one.
See thread "Replacing LLVM_ON_WIN32 with just _WIN32" on llvm-dev and cfe-dev.
No intended behavior change.
llvm-svn: 329696
With this, all output sections are created in one place. This will make
it simpler to implement merging of builtin sections.
Differential Revision: https://reviews.llvm.org/D45349
llvm-svn: 329370
One place where this seems to matter is to make sure the .rsrc section comes
after .text. The Win32 UpdateResource() function can change the contents of
.rsrc. It will move the sections that come after, but if .text gets moved, the
entry point header will not get updated and the executable breaks. This was
found by a test in Chromium.
Differential Revision: https://reviews.llvm.org/D45260
llvm-svn: 329221
/FIXED:NO is always the default, so that part needs no work.
Also test the interaction of /ORDER: with /INCREMENTAL.
https://reviews.llvm.org/D45091
llvm-svn: 328877
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
When investigating bugs in PDB generation, the first step is
often to do the same link with link.exe and then compare PDBs.
But comparing PDBs is hard because two completely different byte
sequences can both be correct, so it hampers the investigation when
you also have to spend time figuring out not just which bytes are
different, but also if the difference is meaningful.
This patch fixes a couple of cases related to string table emission,
hash table emission, and the order in which we emit strings that
makes more of our bytes the same as the bytes generated by MS PDBs.
Differential Revision: https://reviews.llvm.org/D44810
llvm-svn: 328348
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
Reid pointed out the string table for supporting long section names is a
BFD extension and the comments should reflect that. Explicitly spell out
link.exe's and binutil's behavior around section names and the rationale
for LLD's behavior.
Differential Revision: https://reviews.llvm.org/D42659
llvm-svn: 327736
In COFF, duplicate string literals are merged by placing them in a
comdat whose leader symbol name contains a specific prefix followed
by the hash and partial contents of the string literal. This gives
us an easy way to identify sections containing string literals in
the linker: check for leader symbol names with the given prefix.
Any sections that are identified in this way as containing string
literals may be tail merged. We do so using the StringTableBuilder
class, which is also used to tail merge string literals in the ELF
linker. Tail merging is enabled only if ICF is enabled, as this
provides a signal as to whether the user cares about binary size.
Differential Revision: https://reviews.llvm.org/D44504
llvm-svn: 327668
This makes the design a little more similar to the ELF linker and
should allow for features such as ARM range extension thunks to be
implemented more easily.
Differential Revision: https://reviews.llvm.org/D44501
llvm-svn: 327667
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
This makes the output of some flag names in warning messages consistent with
the output of /? and the output of flags in most other diagnostics.
https://reviews.llvm.org/D44307
llvm-svn: 327261
This fixes the broken tests that were causing failures. The tests
before were verifying that the time stamp was 0, but now that we
are actually writing a timestamp, I just removed the match against
the timestamp value.
llvm-svn: 327049
Windows tools treats the timestamp fields as sort of a build id,
using it to archive executables on a symbol server, as well as
for matching executables to PDBs. We were writing 0 for these
fields, which would cause symbol servers to break as they are
indexed in the symbol server based on this value.
Although the field is called timestamp, it can really be any
value that is unique per build, so to support reproducible builds
we use a hash of the executable here.
Differential Revision: https://reviews.llvm.org/D43978
llvm-svn: 326920
For now this is NFC, but this small refactor opens the door to
letting us embed a hash of the PDB in the build id field of the
PDB.
Differential Revision: https://reviews.llvm.org/D43913
llvm-svn: 326453
When merging in types from a type server PDB, we would use a
pointer into the type server PDB's mapped file buffer directly
to avoid copying data. However, we would close the type server
PDB after we finished merging in its types, which would unmap
all of its memory. This would lead to a use after free.
We fix this by making a strong reference in the PDBLinker class
to all referenced type server PDBs, thereby making it safe to
hold pointers into its memory mapped contents.
This fixes llvm.org/pr36455
Differential Revision: https://reviews.llvm.org/D43834
llvm-svn: 326345
This should resolve the issue that lld build fails in some hosts
that uses case-insensitive file system.
Differential Revision: https://reviews.llvm.org/D43788
llvm-svn: 326339
Previously wasm used a separate header to declare markLive
and ELF used to declare ICF. This change makes each backend
consistently declare these in their own headers.
Differential Revision: https://reviews.llvm.org/D43529
llvm-svn: 325631
The profailing style in lld seem to be to not include such empty lines.
Clang-tidy/clang-format seem to handle this just fine.
Differential Revision: https://reviews.llvm.org/D43528
llvm-svn: 325629
Summary:
With D43396, no clients use the Path parameter anymore.
This is the lld side fix with D43400.
Depends on D43396 and D43400.
Reviewers: pcc
Subscribers: emaste, inglorion, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D43401
llvm-svn: 325620
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
This adds an extra level of static safety to our use of placement
new to allocate Symbol types. It prevents the accidental addition
on a non-trivially-destructible member that could allocate and
leak memory.
From the spec: Storage occupied by trivially destructible objects
may be reused without calling the destructor.
Differential Revision: https://reviews.llvm.org/D43244
llvm-svn: 325025
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
Summary: Instead of fatal-ing out when missing a type server PDB, insead warn and cache the miss.
Reviewers: rnk, zturner
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42188
llvm-svn: 323893
I didn't implement the feature in the original patch because I didn't
come up with an idea to do that easily and efficiently. Turned out that
that is actually easy to implement.
In this patch, we collect comdat sections before gc is run and warn on
nonexistent symbols in an order file.
Differential Revision: https://reviews.llvm.org/D42658
llvm-svn: 323699
In my experimentation with link.exe from both VS 2015 and 2017, it
always produces images with truncated section names. Update the comment
accordingly.
Differential Revision: https://reviews.llvm.org/D42603
llvm-svn: 323598
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
Summary:
This detects when an import library is about to be overwritten with a
newly built one with the same contents, and keeps the old library
instead. The use case for this is to avoid needlessly rebuilding
targets that depend on the import library in build systems that rely
on timestamps to determine whether a target requires rebuilding.
This feature was requested in PR35917.
Reviewers: rnk, ruiu, zturner, pcc
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42326
llvm-svn: 323164
There's some abstraction overhead in the underlying
mechanisms that were being used, and it was leading to an
abundance of small but not-free copies being made. This
showed up on a profile. Eliminating this and going back to
a low-level byte-based implementation speeds up lld with
/DEBUG between 10 and 15%.
Differential Revision: https://reviews.llvm.org/D42148
llvm-svn: 322871
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
Patch by Colden Cullen.
Currently, when a large PE (>4 GiB) is to be produced, a crash occurs
because:
1. Calling setOffset with a number greater than UINT32_MAX causes the
PointerToRawData to overflow
2. When adding the symbol table to the end of the file, the last section's
offset was used to calculate file size. Because this had overflowed,
this number was too low, and the file created would not be large enough.
This lead to the actual crash I saw, which was a buffer overrun.
This change:
1. Adds comment to setOffset, clarifying that overflow can occur, but it's
somewhat safe because the error will be handled elsewhere
2. Adds file size check after all output data has been created This matches
the MS link.exe error, which looks prints as: "LINK : fatal error
LNK1248: image size (10000EFC9) exceeds maximum allowable size
(FFFFFFFF)"
3. Changes calculate of the symbol table offset to just use the existing
FileSize. This should match the previous calculations, but doesn't rely
on the use of a u32 that can overflow.
4. Removes trivial usage of a magic number that bugged me while I was
debugging the issue
I'm not sure how to add a test for this outside of adding 4GB of object
files to the repo. If there's an easier way, let me know and I'll be
happy to add a test.
Differential Revision: https://reviews.llvm.org/D42010
llvm-svn: 322605
The compiler could not find the conversion from
unique_ptr<WritableMemoryBuffer> to unique_ptr<MemoryBuffer>. This will
hopefully help it along.
llvm-svn: 322365
Patch by Takuto Ikuta.
This patch reduces lld link time of chromium's blink_core.dll in
component build.
Total size of input argument in .directives become nearly 300MB in the
build and almost all its content are /EXPORT.
To reduce time of parsing too many /EXPORT option in the build, I
introduce fastpath for /EXPORT in ArgParser::parseDirectives.
On my desktop machine, 4 times stats of the link time are like below.
Improved around 20%.
This patch
TotalSeconds : 8.6217627
TotalSeconds : 8.5402175
TotalSeconds : 8.6855853
TotalSeconds : 8.3624441
Ave : 8.5525024
master
TotalSeconds : 10.9975031
TotalSeconds : 11.3409428
TotalSeconds : 10.6332897
TotalSeconds : 10.7650687
Ave : 10.934201075
llvm-svn: 322117
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
Previously, the COFF driver would call exit(1) from the
ErrorHandler in the case of a link error, even if
CanExitEarly=false was specified. Now it initializes
the ErrorHandler in the same way that the ELF driver does.
Patch by Andrew Kelley.
Differential Revision: https://reviews.llvm.org/D41803
llvm-svn: 321983
This is not a record type that clang currently generates,
but it is a record that is encountered in object files generated
by cl. This record is unusual in that it refers directly to
the string table instead of indirectly to the string table via
the FileChecksums table. Because of this, it was previously
overlooked and we weren't remapping the string indices at all.
This would lead to crashes in MSVC when trying to display a
variable whose debug info involved an S_FILESTATIC.
Original bug report by Alexander Ganea
Differential Revision: https://reviews.llvm.org/D41718
llvm-svn: 321883
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
Patch by Takuto Ikuta.
This patch reduces link time of chromium's blink_core.dll in component
build. Total size of input argument in .directives become nearly 300MB
in the build and no rsp file is used. Speedup link by skipping duplicate
parsing.
On my desktop machine, 4 times stats are like below. Improved around 15%.
This patch
TotalSeconds : 18.408538
TotalSeconds : 17.2996744
TotalSeconds : 17.1053862
TotalSeconds : 17.809777
avg: 17.6558439
master
TotalSeconds : 20.9290504
TotalSeconds : 19.9158213
TotalSeconds : 21.0643515
TotalSeconds : 20.8775831
avg: 20.696701575
Differential Revision: https://reviews.llvm.org/D41581
llvm-svn: 321470
/debug and /debug:dwarf are orthogonal. An object file can contain both
CodeView and DWARF debug info, so the combination of /debug:dwarf and
/debug should generate both DWARF and a PDB, rather than /debug:dwarf
always suppressing PDB creation.
/nopdb is now redundant and can be removed. /debug /nopdb was previously
used to support DWARF, but specifying /debug:dwarf is entirely
equivalent to that combination now.
Differential Revision: https://reviews.llvm.org/D41310
llvm-svn: 320896
We can just pass multiple options to hasArgs (which will check for any
of those options being present) instead of calling it multiple times.
llvm-svn: 320892
Locally imported symbols are a very surprising linker feature. link.exe
warns for them, and we should warn too.
Differential Revision: https://reviews.llvm.org/D41269
llvm-svn: 320792
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 is similar to what was added in SVN r277838 for 24 bit
branch instructions.
Differential Revision: https://reviews.llvm.org/D41163
llvm-svn: 320677
This works for linking the output from the MSVC compiler.
The pdata entries for arm64 seem to be 8 bytes in the same
(or at least similar) form to arm.
Differential Revision: https://reviews.llvm.org/D41160
llvm-svn: 320676
In the following command line,
lld-link foo/bar.lib /defaultlib:bar.lib
"/defaultlib:bar.lib" should be a nop even if a file with the same
name exists in other library search path.
Fixes https://bugs.llvm.org/show_bug.cgi?id=35476
Differential Revision: https://reviews.llvm.org/D41094
llvm-svn: 320434
It's pretty annoying to have LLD lowercase paths in error messages when
cross-compiling from a case-sensitive filesystem, since e.g. if I want
to examine the problematic object file, I have to perform some manual
case correction instead of just being able to copy the path from the
error message.
Differential Revision: https://reviews.llvm.org/D40931
llvm-svn: 319996
This patch is to rename check CHECK and make it a C macro, so that
we can evaluate the second argument lazily.
Differential Revision: https://reviews.llvm.org/D40915
llvm-svn: 319974
Adds support for "/ENTRY" and "/SUBSYSTEM" linker options in .drectve
sections. Some Mozilla binaries were using these directives and MSVC
link.exe appears to allow them. No attempt is made to reconcile these
with the options on the command line.
Patch by David Major!
Differential Revision: https://reviews.llvm.org/D39972
llvm-svn: 319356
A couple of places in LLD were passing references to
TypeTableCollections around, which makes it hard to change the
implementation at runtime. However, these cases only needed to
iterate over the types in the collection, and TypeCollection
already provides a handy abstract interface for this purpose.
By implementing this interface, we can get rid of the need to
pass TypeTableBuilder references around, which should allow us
to swap the implementation at runtime in subsequent patches.
llvm-svn: 319345
GNU ld has got an exception for such symbols, and mingw-w64
occasionally uses that exception to avoid exporting symbols in cases
where they otherwise aren't caught by the other exclusion mechanisms.
Differential Revision: https://reviews.llvm.org/D40553
llvm-svn: 319291
Instead of building intermediate sets of exception handlers for each
object file, just create one for the final output file.
Differential Revision: https://reviews.llvm.org/D40581
llvm-svn: 319244
This allows grouping all sections like ".ctors.12345" into ".ctors".
For MinGW, the numerical values for such ctors are all zero-padded,
so a lexical sort is good enough.
Differential Revision: https://reviews.llvm.org/D40408
llvm-svn: 319151
If /debug was not specified, readSection will return a null
pointer for debug sections. If the debug section is associative with
another section, we need to make sure that the section returned from
readSection is not a null pointer before adding it as an associative
section.
Differential Revision: https://reviews.llvm.org/D40533
llvm-svn: 319133
With this change, instead of creating a SectionChunk for each section
in the object file, we only create them when we encounter a prevailing
comdat section.
Also change how symbol resolution occurs between comdat symbols. Now
only the comdat leader participates in comdat resolution, and not any
other external associated symbols. This is more in line with how COFF
semantics are defined, and should allow for a more straightforward
implementation of non-ANY comdat types.
On my machine, this change reduces our runtime linking a release
build of chrome_child.dll with /nopdb from 5.65s to 4.54s (median of
50 runs).
Differential Revision: https://reviews.llvm.org/D40238
llvm-svn: 319090
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
Summary: MSVC does this. The user can override it with their own /merge: flag.
Reviewers: ruiu, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40197
llvm-svn: 318699
Don't crash if we encounter a reference to an early discarded section
(such as .drectve). Instead, handle them the same way as sections
discarded by comdat merging, i.e. either print an error message or
(for debug sections) silently ignore the relocation.
Differential Revision: https://reviews.llvm.org/D40235
llvm-svn: 318689
This requirement was added in r254578 to fix pr25686. However, it
appears to have originated from a misdiagnosis of the problem: link.exe
refused to merge the two sections because they are non-executable,
not because they have internal leaders. If I set up a similar scenario
with functions instead of globals I see that link.exe merges them.
Differential Revision: https://reviews.llvm.org/D40236
llvm-svn: 318682
Now that our support for PDB emission is reasonably good, there is
no longer a need to emit a COFF symbol table.
Also fix a bug where we would fail to emit a string table for long
section names if /debug was not specified.
Differential Revision: https://reviews.llvm.org/D40189
llvm-svn: 318548
Summary:
Many small functions have identical unwind info because they push the
same sets of CSRs in the same order and have the same stack and prologue
size. The VC linker merges duplicate .xdata, and so should LLD.
This reduces the .xdata section size of clang.exe from 1.8MB to 94KB.
Reviewers: pcc, ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40160
llvm-svn: 318547
Sections that will be mapped at runtime will only have the short
section name available, since the string table it points into isn't
mapped. Therefore prefer truncating those names over writing a
long name that is unavailable at runtime.
This allows libunwind to find the .eh_frame section at runtime even
if the module was built with debug info enabled.
Differential Revision: https://reviews.llvm.org/D40025
llvm-svn: 318391
If -opt:noref is specified, they can end up with isLive() == 1
when the autoexport check is run.
To reduce the risk of potential issues, only consider exporting
DefinedRegular and DefinedCommon, nothing else.
Differential Revision: https://reviews.llvm.org/D40014
llvm-svn: 318384
Summary:
We previously assumed that all SafeSEH handlers are
DefinedRegular symbols. This is not the case for handlers defined in
DLLs. As a result, we were failing to emit entries in the SafeSEH
table for those handlers. This change fixes that.
Fixes PR35324.
Reviewers: rnk, ruiu
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40102
llvm-svn: 318364
Even if we don't actually write any string table contents, the
4 byte size for the string table will always be written. Make
sure we accommodate for this in the file size. Since this size
is aligned up, this would seldom be an issue in practice.
Differential Revision: https://reviews.llvm.org/D39891
llvm-svn: 318284
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
ICF and GC impair debugging, so MSVC disables these optimizations when
/debug is passed. They are still on by default when no PDB is produced.
This change also makes /opt:ref enable ICF, which is consistent with
MSVC: https://msdn.microsoft.com/en-us/library/bxwfs976.aspx
We should consider making /opt:icf fold readonly data in the near
future. LLD used to do this, but we disabled it because it breaks too
many programs. MSVC only does this if the user explicitly passes
/opt:icf.
Reviewers: ruiu, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39885
llvm-svn: 318071
I never ran into this until lld-link started enabling debug output
by default for the mingw mode. I haven't been able to verify that
this actually behaves correctly, but this relocation is handled
identically on all other architectures so far.
Differential Revision: https://reviews.llvm.org/D39754
llvm-svn: 317669
Summary:
__safe_se_handler_base should be either absolute 0 (when no SafeSEH
table is present), or relative to the image base (when the table is
present). An earlier change inadvertedly made the symbol absolute in
both cases, leading to the SafeSEH table not being locatble at run
time. This change fixes that and updates the safeseh test to check for
the presence of the relocation.
Reviewers: rnk, ruiu
Reviewed By: ruiu
Subscribers: ruiu, llvm-commits
Differential Revision: https://reviews.llvm.org/D39765
llvm-svn: 317635
These libraries contain a number of object files with compat wrappers,
in addition to the normal import library entries.
Differential Revision: https://reviews.llvm.org/D39684
llvm-svn: 317505
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
This patch resurrects code that was removed in r317007 to not access
beyond allocated memory for a symbol.
Differential Revision: https://reviews.llvm.org/D39458
llvm-svn: 317039
IIUC, SizeOfImage is the distance from the end of the last section to
the image base, rounded up to the page size. So the previous code is
wrong.
Should fix https://bugs.llvm.org/show_bug.cgi?id=34949
(It is nice to know that lld is already being used to create Putty
distribution binaries.)
llvm-svn: 316626
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
If /manifest:embed is enabled we're already creating a resource file
out of these flags and adding it to the linkrepro, and it doesn't
seem worth being able to repro side-by-side manifests.
Includes a test that covers this commit as well as r315948.
Differential Revision: https://reviews.llvm.org/D38975
llvm-svn: 316547
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
LLD's handling of boolean flags is suboptimal:
* All boolean flags have a corresponding `:no` flag to turn the flag
off, and the linker should scan for both the non-suffixed and suffixed
flags (and the last one should win), but right now it only scans for
either the suffixed or non-suffixed flag (depending on the default
flag value).
* The `B` multiclass only allows specifying help text for the suffixed
(`:no`) flag, but for some flags (e.g. `/appcontainer`) the help text
should be associated with the non-suffixed flag instead.
Extend the `B` multiclass to have help text for both non-suffixed and
suffixed flag variants, and alter the existing help text accordingly in
some cases. Scan for both the non-suffixed and suffixed variants in the
driver and set config values accordingly.
This should mostly have no behavior change, apart from the added help
text and the modified argument scanning. Some flags are handled slightly
differently now, however; for example, LLD would previously always treat
64-bit images as large address aware, whereas `/largeaddressaware:no` is
now respected for 64-bit images (which is also how link.exe behaves).
Differential Revision: https://reviews.llvm.org/D39216
llvm-svn: 316501
The type index is from the TPI stream, not the IPI stream. Fix the
dumper, fix type index discovery, and add a test in LLD.
Also improve the log message we emit when we fail to rewrite type
indices in LLD. That's how I found this bug.
llvm-svn: 316461
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
This fixes exporting functions in the following cases:
- functions starting with an underscore in def files
- functions starting with an underscore, via dllexport attributes, for mingw
- fastcall and vectorcall functions when declared undecorated in def files
- vectorcall functions when declared decorated in def files
- stdcall functions when declared decorated in def files for mingw
This still exports the stdcall functions with the wrong name
in the normal msvc/link.exe mode, if declared with decoration in
the def file though (this is not a regression though). Exporting
functions via def files including decoration is not something I
believe is routinely done though, but is tested to try to match
link.exe's behaviour as far as easily possible.
Differential Revision: https://reviews.llvm.org/D39170
llvm-svn: 316317
This should fix the build after SVN r316178, which worked fine
on GCC 5.4, but failed on clang with errors like these:
MinGW.h:26:3: error: too few template arguments for class template 'StringSet'
StringSet<> ExcludeSymbols;
^
lld/Common/LLVM.h:28:30: note: template is declared here
template<typename T> class StringSet;
Don't forward declare and add the using directive in the main
lld/Common/LLVM.h header, but just qualify the class name
in MinGW.h instead.
llvm-svn: 316180
Now that we have our own implementation of cvtres, we can add resource
files directly to the linkrepro.
Differential Revision: https://reviews.llvm.org/D38974
llvm-svn: 315954
Without this, /linkrepro would create an invalid tar file.
No tests because this requires Windows and the linkrepro tests
require not-Windows.
Differential Revision: https://reviews.llvm.org/D38973
llvm-svn: 315948
GNU ld automatically exports all symbols if no symbols have
been chosen to export via either def files or dllexport attributes.
The same behaviour can also be enabled via the GNU ld option
--export-all-symbols, in case some symbols are marked for export
via a def file or dllexport attribute.
The list of excluded symbols is from GNU ld, minus the
cygwin specific symbols.
Also add support for outputting the actual list of exported
symbols in a def file, as in the GNU ld option --output-def.
These options in GNU ld are documented in
https://sourceware.org/binutils/docs/ld/WIN32.html.
This currently exports all symbols from object files pulled in
from libmingw32 and libmingwex and other static libraries
that are linked in.
Differential Revision: https://reviews.llvm.org/D38760
llvm-svn: 315562
This is implemented in the same way as the other ADDR32NB relocations
for ARM and X64.
Differential Revision: https://reviews.llvm.org/D38815
llvm-svn: 315561
Fixes PR34306.
This is because it usually results in more compact code, and because
there are also known code generation bugs when using the PIC model
(see bug).
Based on a patch by Carlo Kok.
Differential Revision: https://reviews.llvm.org/D38769
llvm-svn: 315400
I believe the reason why we used warn() instead of error() to report
undefined symbols is because the older implementation of error() exitted
immediately. Here, we want to find as many undefined symbols as we can,
so I chose to use warn() instead of error().
Now error() does not exit immediately, so it doesn't make sense to keep
them as warnings.
Differential Revision: https://reviews.llvm.org/D38652
llvm-svn: 315131
New lld's files are spread under lib subdirectory, and it isn't easy
to find which files are actually maintained. This patch moves maintained
files to Common subdirectory.
Differential Revision: https://reviews.llvm.org/D37645
llvm-svn: 314719
Computing section content hashes early seems like a win in terms of
performance. It increases a chance that two different sections will get
different class IDs from the beginning.
Without threads, this patch improves Chromium link time by about 0.3
seconds. With threads, by 0.1 seconds. That's less than 1% time saving
but not bad for a small patch.
llvm-svn: 314644
According to Microsoft's PE/COFF documentation, a SECREL relocation is
"The 32-bit offset of the target from the beginning of its section". By
my reading, the "from the beginning of its section" implies that the
offset is unsigned.
Change from an assertion to an error, since it's possible to trigger
this condition normally for input files with very large sections, and we
should fail gracefully for those instead of asserting.
Differential Revision: https://reviews.llvm.org/D38020
llvm-svn: 313703
Sections are limited to 4 GiB. Error out early if a section exceeds this
size, rather than overflowing the section size and getting confusing
assertion failures/segfaults later.
Differential Revision: https://reviews.llvm.org/D38005
llvm-svn: 313699
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
Arg instances can be claimed. After claimed, its `isClaimed` function
returns true. We do not use that notion in lld, so using NoClaim
versions of functions is just confusing. This patch is to just use
hasArg instead of hasArgNoClaim.
llvm-svn: 313187
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
/natvis is a new command line option introduced by MSVC 2017.
We eventually have to support it, but for now, let's ignore it so that
we can at least link stuff instead of printing out an error.
Patch by Michael Rickert.
llvm-svn: 312966
Summary:
Previous would throw warning whenever libxml2 is not installed. Now
only give this warning if merging manifest fails.
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37240
llvm-svn: 312604
Looks like raw_string_ostream is buffered. If we do not call `flush`
nor `str`, it is not guaranteed that a result string has all characters
that were written to it.
It wasn't failing on buildbots, but I could reproduce the issue on my
Windows workstation.
llvm-svn: 312577
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
writeArchive returned a pair, but the first element of the pair is always
its first argument on failure, so it doesn't make sense to return it from
the function. This patch change the return type so that it does't return it.
Differential Revision: https://reviews.llvm.org/D37313
llvm-svn: 312177
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
Takuto Ikuta