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 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
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
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 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
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
/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
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
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
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
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
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
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
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 /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 support for reporting multiple errors in a single invocation of lld-link. The limit defaults to 20 and can be changed with the /ERRORLIMIT command line parameter, or set to unlimited by passing a value of 0.
This is a new attempt after r295507, which was reverted because opening files raced with exiting early, causing the test to be flaky. This version avoids the race by exiting before calling enqueuePath.
Reviewers: pcc, ruiu
Reviewed By: ruiu
Subscribers: llvm-commits, dblaikie
Differential Revision: https://reviews.llvm.org/D31688
llvm-svn: 299496
This will be used in the sanitizer test suite, which wants to use DWARF
line tables.
At some point we should reconsider how LLD handles the long section
names required by DWARF debug sections.
llvm-svn: 298544
Behavior races on ErrorCount. If the enqueued paths are evaluated
eagerly (in enqueuePath) then the behavior is as the test expects. But
they may not be evaluated until the future is waited on, in run() -
which is after the early return/exit on ErrorCount. (this causes the
test to fail (because in the "/ERRORCOUNT:XYZ" test, no other errors
are printed), at least for me, on linux)
This reverts commit r295507.
llvm-svn: 295590
Summary: This adds support for reporting multiple errors in a single invocation of lld-link. The limit defaults to 20 and can be changed with the /ERRORLIMIT command line parameter, or set to unlimited by passing a value of 0.
Reviewers: pcc, ruiu
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D29691
llvm-svn: 295507
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
This patch defines a new command line option, /MSVCLTO, to LLD.
If that option is given, LLD invokes link.exe to link LTO-generated
object files. This is hacky but useful because link.exe can create
PDB files.
Differential Revision: https://reviews.llvm.org/D29526
llvm-svn: 294234
The former option bases the filename on the output name, e.g. if the
link output is a.exe, the map will be written to a.map. This matches the
behaviour of link.exe's /MAP option and is useful for creating a map
file of each executable when building a large project.
Differential Revision: https://reviews.llvm.org/D27595
llvm-svn: 289271
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
Add the support infrastructure for the /debugtype option which takes a comma
delimited list of debug info to generate. The defaults are based on other
options potentially (/driver or /profile). This sets up the infrastructure to
allow us to emit RSDS records to get "build id" equivalents on COFF (similar to
binutils).
llvm-svn: 278056
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
Manifest file is a separate or embedded XML file having metadata
of an executable. As it is XML, it can contain various types of
information. Probably the most popular one is to request escalated
priviledges.
Usually the linker creates an XML file and embed that file into
an executable. However, there's a way to supply an XML file from
command line. /manifestniput is it.
Apparently it is over-designed here, but if you supply two or more
manifest files, then the linker needs to merge the files into a
single XML file. A good news is that we don't need to do that ourselves.
MT.exe command can do that, so we call the command from the linker
in this patch.
llvm-svn: 266704
This flag disables link.exe's crash handler so that normal windows error
reporting and crash dumping occurs. For now it is reasonable for LLD to
ignore the flag.
Chromium is currently using this flag to collect minidumps of link.exe
crashing, and it breaks the LLD build.
llvm-svn: 264439
This is an LLD extension to MSVC link.exe command line. MSVC linker
does not write symbol tables for executables. We do unless no /debug
option is given.
There's a situation that we want to enable debug info but don't want
to emit the symbol table. One example is when we are comparing output
file size. With this patch, you can tell the linker to not create
a symbol table by just specifying /nosymtab.
llvm-svn: 248225
The option is added in MSVC 2015, and there's no documentation about
what the option is. This patch is to ignore the option for now, so that
at least LLD is usable with MSVC 2015.
llvm-svn: 246780
Nico Weber