The linker refuses using -dynamicbase:no on these architectures.
Stop passing -dynamicbase (which just reinforces the lld-link
default) for simplicity.
Differential Revision: https://reviews.llvm.org/D41052
llvm-svn: 320518
Moving the SHF_LINK_ORDER processing out of OutputSection::finalize()
means that we no longer need to copy all InputSections as we now only need
the first one.
Differential Revision: https://reviews.llvm.org/D40966
llvm-svn: 320478
By moving this step before thunk creation and other processing that depends
on the size of sections, we permit removal of duplicates in the .ARM.exidx
section.
Differential Revision: https://reviews.llvm.org/D40964
llvm-svn: 320477
The size of an OutputSection is calculated early, to aid handling of compressed
debug sections. However, subsequent to this point, unused synthetic sections are
removed. In the event that an OutputSection, from which such an InputSection is
removed, is still required (e.g. because it has a symbol assignment), and no longer
has any InputSections, dot assignments, or BYTE()-family directives, the size
member is never updated when processing the commands. If the removed InputSection
had a non-zero size (such as a .got.plt section), the section ends up with the
wrong size in the output.
The fix is to reset the OutputSection size prior to processing the linker script
commands relating to that OutputSection. This ensures that the size is correct even
in the above situation.
Additionally, to reduce the risk of developers misusing OutputSection Size and
InputSection OutSecOff, they are set to simply the number of InputSections in an
OutputSection, and the corresponding index respectively. We cannot completely
stop using them, due to SHF_LINK_ORDER sections requiring them.
Compressed debug sections also require the full size. This is now calculated in
maybeCompress for these kinds of sections.
Reviewers: ruiu, rafael
Differential Revision: https://reviews.llvm.org/D38361
llvm-svn: 320472
By using an index instead of a pointer for verdef we can put the index
next to the alignment field. This uses the otherwise wasted area and
reduces the shared symbol size.
By itself the performance change of this is in the noise, but I have a
followup patch to remove another 8 bytes that improves performance
when combined with this.
llvm-svn: 320449
An internal linker has support for merging identical data and in some
cases it can be a significant win.
This is behind an off by default flag so it has to be requested
explicitly.
llvm-svn: 320448
Also make function bodies unique so they can be distinguished
in the output. This is helpful for adding support for --gc-sections.
Differential Revision: https://reviews.llvm.org/D41093
llvm-svn: 320441
When an output section has no byte commands and has no input sections then it
would be ideal if the type of the section is SHT_NOBITS so that the file can
take up less space. This change sets the default type of of output sections to
SHT_NOBITS instead of SHT_PROGBITS to allow this. This required some minor test
changes (which double as tests for this new behavior) but extend-pt-load.s had
be changed in a non-trivial way. Since it seems to me that the point of the
test is to point out the consequences of how flags are assigned to output
sections that don't have input sections I changed the test to work and still
show how the memsize of the executable segment was changed.
Differential Revision: https://reviews.llvm.org/D41082
llvm-svn: 320437
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
The PPC port doesn't support PLT yet, but the architecture independent
code optimizes PLT access for non preemptible symbols, which is
exactly what returning R_PC was trying to implement.
llvm-svn: 320430
Create the indirect function table based on symbols rather
than just duplicating the input entries. This has the
effect of de-duplicating the table.
This is a followup to the equivalent change made for globals:
https://reviews.llvm.org/D40859
Partially based on a patch by Nicholas Wilson:
https://reviews.llvm.org/D40845
Differential Revision: https://reviews.llvm.org/D40989
llvm-svn: 320428
log are also diagnostics so it seems like they should to
the same place as errors and debug messages.
Without this change when I enable --verbose those messages
go to stdout, but when I enable "-mllvm -debug" those messages
go to stderr (because dbgs() goes to stderr by default).
So I end up having to do this a lot:
lld <args> > output_message 2>&1
Differential Revision: https://reviews.llvm.org/D41033
llvm-svn: 320427
Now that gc sections runs after linker defined symbols are added it
can see symbols that point to an OutputSection.
Should fix a bot failure.
llvm-svn: 320412
This fixes pr35570.
We were creating these symbols after parsing version scripts, so they
could not be versioned.
We cannot move the version script parsing later because we need it for
lto.
One option is to move both addReservedSymbols and
createSyntheticSections earlier. The disadvantage is that some
sections created by createSyntheticSections replace other input
sections. For example, gdb index replaces .debug_gnu_pubnames, so it
wants to run after gc sections so that it can set S->Live to false.
What this patch does instead is to move just the ElfHeader creation
early.
llvm-svn: 320390
Add test for weakly defined symbols with the same name
Improve test for call-indirect to include the same call in two
different objects. This lays the ground work to improve the
output via de-duplicating the indirect call table:
https://reviews.llvm.org/D40989
Also make all tests consistently pass -mtriple rather than
declaring in the sources.
Differential Revision: https://reviews.llvm.org/D41024
llvm-svn: 320172
This adds a `--no-entry` argument to wasm LLD used to
suppress the default `_start` entry point.
Patch by Nicholas Wilson!
Differential Revision: https://reviews.llvm.org/D40725
llvm-svn: 320167
Summary:
I also changed the message to print both the ISA and the the architecture
name for incompatible files. Previously it would be quite hard to find the
actual path of the incompatible object files in projects that have many
object files with the same name in different directories.
Reviewers: atanasyan, ruiu
Reviewed By: atanasyan
Subscribers: emaste, sdardis, llvm-commits
Differential Revision: https://reviews.llvm.org/D40958
llvm-svn: 320056
Adds a new argument to wasm-lld, `--undefined`, with
similar semantics to the ELF linker. It pulls in symbols
from files contained within a `.a` archive, forcing them
to be included even if the translation unit would not
otherwise be pulled in.
Patch by Nicholas Wilson
Differential Revision: https://reviews.llvm.org/D40724
llvm-svn: 320004
This change cleans up the way wasm exports and globals
are generated, particualrly for -r/--relocatable where
globals need to be created and exported in order for
output relocations which reference them.
Remove the need for a per file GlobalIndexOffset and
instead set the output index for each symbol directly.
This simplifies the code in several places.
Differential Revision: https://reviews.llvm.org/D40859
llvm-svn: 320001
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 reduces total allocations when linking clang fsds from 263.21MB
to 174.62MB.
This also has some very nice speed improvements on some
benchmarks. Chromium and clang fsds link 6% faster.
llvm-svn: 319976
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
Summary:
We want to automatically copy the appropriate mailing list
for review requests to the LLD repository.
For context, see the proposal and discussion here:
http://lists.llvm.org/pipermail/cfe-dev/2017-November/056032.html
Similar to D40179, I set up a new Diffusion repository with callsign
"LLD" for lld:
https://reviews.llvm.org/source/lld/
This explicitly updates lld's .arcconfig to point to the new C
repository in Diffusion, which will let us use Herald rule H270.
Reviewers: peter.smith, ruiu, rafael, sammccall
Reviewed By: sammccall
Subscribers: dlj, bkramer, sammccall, klimek
Differential Revision: https://reviews.llvm.org/D40495
llvm-svn: 319955
This avoids allocating the error message when there is no error that
check requires.
It avoids the code duplication of inlining check.
llvm-svn: 319922
As mentioned in PR35471, shared functions for which
.plt entry address is used shows up in bfd's map files.
Patch teaches LLD to do the same.
Differential revision: https://reviews.llvm.org/D40839
llvm-svn: 319879
This file contained only a single function that was only
really needed in one place, so just inline it.
Differential Revision: https://reviews.llvm.org/D40870
llvm-svn: 319876
We fill executable sections with trap instructions (0xcc or equivalent).
If a .gnu.hash section was put into an executable segment, we created
corrupted .gnu.hash section. This patch fixes the issue.
llvm-svn: 319863
We currently use target_link_libraries without an explicit scope
specifier (INTERFACE, PRIVATE or PUBLIC) when linking executables.
Dependencies added in this way apply to both the target and its
dependencies, i.e. they become part of the executable's link interface
and are transitive.
Transitive dependencies generally don't make sense for executables,
since you wouldn't normally be linking against an executable. This also
causes issues for generating install export files when using
LLVM_DISTRIBUTION_COMPONENTS. For example, clang has a lot of LLVM
library dependencies, which are currently added as interface
dependencies. If clang is in the distribution components but the LLVM
libraries it depends on aren't (which is a perfectly legitimate use case
if the LLVM libraries are being built static and there are therefore no
run-time dependencies on them), CMake will complain about the LLVM
libraries not being in export set when attempting to generate the
install export file for clang. This is reasonable behavior on CMake's
part, and the right thing is for LLVM's build system to explicitly use
PRIVATE dependencies for executables.
Unfortunately, CMake doesn't allow you to mix and match the keyword and
non-keyword target_link_libraries signatures for a single target; i.e.,
if a single call to target_link_libraries for a particular target uses
one of the INTERFACE, PRIVATE, or PUBLIC keywords, all other calls must
also be updated to use those keywords. This means we must do this change
in a single shot. I also fully expect to have missed some instances; I
tested by enabling all the projects in the monorepo (except dragonegg),
and configuring both with and without shared libraries, on both Darwin
and Linux, but I'm planning to rely on the buildbots for other
configurations (since it should be pretty easy to fix those).
Even after this change, we still have a lot of target_link_libraries
calls that don't specify a scope keyword, mostly for shared libraries.
I'm thinking about addressing those in a follow-up, but that's a
separate change IMO.
Differential Revision: https://reviews.llvm.org/D40823
llvm-svn: 319840
This line was mistakenly deleted in rL319813
Add a test for stackpointer relocations.
Differential Revision: https://reviews.llvm.org/D40847
llvm-svn: 319828
This is part of larger change to add synthetic symbols
for section start/end points and init/fini_array:
https://reviews.llvm.org/D40760
Allows synthetic global symbols to have an explicitly set
virtual address.
Differential Revision: https://reviews.llvm.org/D40843
llvm-svn: 319813
This is a small change I split of from a larger one
that simplifies the condition that need to be checked
when decided if we need to emit relocation and all the
things they depend on (symbols, etc).
Differential Revision: https://reviews.llvm.org/D40825
llvm-svn: 319789
Add a new file AArch64ErrataFix.cpp that implements the logic to scan for
the Cortex-A53 Erratum 843419. This involves finding all the executable
code, disassembling the instructions that might trigger the erratum and
reporting a message if the sequence is detected.
At this stage we do not attempt to fix the erratum, this functionality
will be added in a later patch. See D36749 for proposal.
Differential Revision: https://reviews.llvm.org/D36742
llvm-svn: 319780
With fix:
Specify -soname for input dso to fix up the .dynstr section
size in different environments.
Original commit message:
As mentioned in PR35471, copied symbols did not show
in --Map output. Patch fixes that.
Differential revision: https://reviews.llvm.org/D40785
llvm-svn: 319769
When a linker script is used with a pattern like { *(.bss .bss.*) } the
InX::BssRelRo section will match against .bss.*. By matching on the name
only, in the same way that .data.rel.ro works we prevent this
from happening, but permit scripts that want to explicitly provide
a .bss.rel.ro OutputSection.
Differential Revision: https://reviews.llvm.org/D40735
llvm-svn: 319755
As mentioned in PR35471, copied symbols did not show
in --Map output. Patch fixes that.
Differential revision: https://reviews.llvm.org/D40785
llvm-svn: 319747
Previously, lld exited with an error status if the only option given to
the command was -v. GNU linkers gracefully exit in that case. This patch
makes lld behave like GNU.
Note that even with this patch, lld's -v and --version options behave
slightly differently than GNU linkers' counterparts. For example,
if you run `ld.bfd -v -v`, the version string is printed out twice.
But that is an edge case that I don't think we need to take care of.
Fixes https://bugs.llvm.org/show_bug.cgi?id=31582
Differential Revision: https://reviews.llvm.org/D40810
llvm-svn: 319717
As well as location counter expressions. The data generating expressions
such as BYTE can generate a non-zero sized OutputSection that will report
0 until assignAddresses() is called. Add an example to the existing test
case relro-non-contiguous-script-data.s.
Differential Revision: https://reviews.llvm.org/D40732
llvm-svn: 319648
This change actually makes the linker slightly faster. My observation
is that, with this patch, link time of clang without debug is about 1%
faster.
Differential Revision: https://reviews.llvm.org/D40697
llvm-svn: 319600
PR35478 https://bugs.llvm.org/show_bug.cgi?id=35478 points out a flaw
in the implementation of r318924 from D40364. The implementation
depends on the Size field being set or the SyntheticSection::empty()
being accurate. These functions are not reliable as some linker script
commands that have yet to be processed may affect the results, causing
some non-zero size sections to be reported as zero size.
I think the first step is to revert r318924 and come up with a better
solution for the underlying problem rather than trying to layer more
heuristics onto the zero sized output section.
Chances are I'll be out of office by the time anyone sees this so feel
free to commit the revert if you agree with me.
Fixes PR35478
Current thoughts on the underlying problem:
Revisiting the motivation for adding the zero size check in the first
place; it was to prevent 0 sized SyntheticSections that a user does
not have full control over from needlessly breaking the PT_GNU_RELRO,
rather than trying to accommodate arbitrarily complex linker
scripts. Looking at the code, it looks like
removeUnusedSyntheticSections() should remove zero sized synthetic
sections. It does, but it doesn't set the Parent to nullptr, this has
the side effect that Sec == InX::BssRelRo->getParent() will make the
parent OutputSection of InX::BssRelRo RelRo even if there is no
InX::BssRelRo.
I tried a quick experiment with setting the Parent to nullptr and this
flushed out a few interesting test failures, it feels like playing
Jenga with every change:
In the isRelroSection() we have to consider the case where there
is no .plt and .plt.got but there is a ifunc plt with accompanying
(ifunc .got or .plt.got)
The PPC64 has PltHeaderSize == 0. Unfortunately HeaderSize == 0 is
used to choose between the ifunc plt or normal plt. We seem to get
away with this at the moment, but tests start to fail when Parent
is set to nullptr for the .got.plt.
The InX::BssRelRo and InX::Bss never get their sizes set and they
are always removed by removeUnusedSyntheticSections(), their
purpose seems to be as some kind of proxy for add .bss or
.bss.relro InputSections into their parent OutputSections, they
therefore don't behave like other SyntheticSections anyway.
My thinking is that some work is needed to make sure that the Sec ==
SyntheticSection->getParent() does a bit more checking before
returning true, particularly for InX::BssRelRo as that has special
behaviour. I'll hope to post something for review as soon as possible.
Patch by Peter Smith!
llvm-svn: 319563
This is for "Bug 35474 - --emit-relocs produces wrongly-named reloc sections".
LLD currently for scripts like:
.text.boot : { *(.text.boot) }
emits relocation section with name .rela.text because does not take
redefined name of output section into account and builds section name
using rules for non-scripted case. Patch fixes this oddness.
Differential revision: https://reviews.llvm.org/D40652
llvm-svn: 319526
We had no tests for what PROVIDE should do if there is a shared symbol
with the same name.
In both bfd and our existing implementation PROVIDE wins. Add a test
for that.
llvm-svn: 319486
The ELF spec says
Symbols with section index SHN_COMMON may appear only in relocatable
objects.
Currently lld can produce file that break that requirement.
llvm-svn: 319473
When a linker script has "foo = bar" and bar is the result of a copy
relocation foo should point to the same location in .bss.
This is part of a growing evidence that copy relocations should be
implemented by using replaceSymbol to replace the SharedSymbol with a
Defined.
llvm-svn: 319449
Since MarkLive.cpp is the place where we set Live flags for
other sections, it looks correct to do that there.
Benefit is that we stop spreading GC logic outsize of MarkLive.cpp.
Differential revision: https://reviews.llvm.org/D40454
llvm-svn: 319435
This change allows checking of function signatures but
does not yes enable it by default. In this mode, linking
two objects that were compiled with a different signatures
for the same function will produce a link error.
New options for enabling and disabling this feature have been
added: (--check-signatures/--no-check-signatures).
Differential Revision: https://reviews.llvm.org/D40371
llvm-svn: 319396
std::set is pretty slow. We generally prefer llvm::StringSet if we don't
need an sorted set.
Differential Revision: https://reviews.llvm.org/D40579
llvm-svn: 319371
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
The AArch64 unconditional branch and branch and link instructions have a
maximum range of 128 Mib. This is usually enough for most programs but
there are cases when it isn't enough. This change adds support for range
extension thunks to AArch64. For pc-relative thunks we follow the small
code model and use ADRP, ADD, BR. This has a limit of 4 gigabytes.
Differential Revision: https://reviews.llvm.org/D39744
llvm-svn: 319307
The SHT_ARM_ATTRIBUTES section type is in the processor specific space
adding guard to make sure that it is only recognized when EMachine is
EM_ARM.
llvm-svn: 319304
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
These should get initialized in by Driver.cpp based on
command line options.
Also, sort entries.
Differential Revision: https://reviews.llvm.org/D40570
llvm-svn: 319219
It had been reverted because it depended on r319008 which has been
recommitted.
Original message:
Add a missing test.
We were not testing that we correctly handled a .o with a weak symbol
after a .so.
llvm-svn: 319217
This includes a fix to mark copy reloc aliases as used.
Original message:
[ELF] Do not keep symbols if they referenced only from discarded sections.
This patch also ensures that in case of "--as-needed" is used,
DT_NEEDED entries are not created if they are required only by
these eliminated symbols.
llvm-svn: 319215
lld assumes some ARM features that are not available in all Arm
processors. In particular:
- The blx instruction present for interworking.
- The movt/movw instructions are used in Thunks.
- The J1=1 J2=1 encoding of branch immediates to improve Thumb wide
branch range are assumed to be present.
This patch reads the ARM Attributes section to check for the
architecture the object file was compiled with. If none of the objects
have an architecture that supports either of these features a warning
will be given. This is most likely to affect armv6 as used in the first
Raspberry Pi.
Differential Revision: https://reviews.llvm.org/D36823
llvm-svn: 319169
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
Currently we mark every shared symbol as STB_WEAK.
That is a hack to make it easy to decide when a .so is needed or not
because of a reference to a given symbol.
That hack leaks when we create copy relocations as shown by the update
to relocation-copy-alias.s.
This patch stores the original binding when we first read a shared
symbol. We still have to update the binding to weak if we see a weak
undef, but I find the logic easier to read where it is now.
llvm-svn: 319127
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
When an undefined weak reference has a PLT entry we must generate a range
extension thunk for any B or BL that can't reach the PLT entry.
This change explicitly looks for whether a PLT entry exists rather than
assuming that weak references never need PLT entries unless Config->Shared
is in operation. This covers the case where we are linking an executable
with dynamic linking, hence a PLT entry will be needed for undefined weak
references. This case comes up in real programs over 32 Mb in size as there
is a B to a weak reference __gmon__start__ in the Arm crti.o for glibc.
Differential Revision: https://reviews.llvm.org/D40248
llvm-svn: 319020
This patch also ensures that in case of "--as-needed" is used,
DT_NEEDED entries are not created if they are required only by
these eliminated symbols.
Differential Revision: https://reviews.llvm.org/D38790
llvm-svn: 319008
LLD uses .bss.rel.ro for read-only copy relocations whereas the ld.bfd and
gold linkers use .data.rel.ro. In some linker scripts including ld.bfd's
internal linker script, the relro sections are placed sequentially assuming
.data.rel.ro is used. LLD's use of .bss.rel.ro means that the copy
relocations get matched into the .bss section causing the relro sections to
be non-contiguous.
This change checks for a .data.rel.ro OutputSection when a linker script
with the SECTIONS command is used. The section will match in the
.data.rel.ro output section and will maintain contiguous relro.
Differential Revision: https://reviews.llvm.org/D40365
Fixes PR35265
llvm-svn: 318940
It now has a DT_NEEDED that could be removed by --gc-sections and one
that cannot. Without this all tests would pass if --gc-sections just
removed all DT_NEEDED.
llvm-svn: 318937
When checking for contiguous relro sections we can skip over empty sections.
If there is an empty non-relro section in the middle of a contiguous block
of relro sections then it cannot be written to so it is safe to include in
PT_GNU_RELRO header. If there is a contiguous block of empty relro sections
then no PT_GNU_RELRO header is required for them.
Differential Revision: https://reviews.llvm.org/D40364
llvm-svn: 318924
If a linker script is used that names linker generated synthetic sections
it is possible that the OutputSections for which isRelroSection() is true
are not contiguous. When the relro sections are not contiguous we cannot
describe them with a single PT_GNU_RELRO PHDR. Unfortunately at least one
contemporary dynamic loader only supports one PT_GNU_RELRO PHDR so we
cannot output more than one of these PHDRs. As not including relro
sections in the PHDR will lead to security sensitive sections being
writeable we choose to give an error message instead.
Differential Revision: https://reviews.llvm.org/D40359
[ELF] Skip over empty sections when checking for contiguous relro
llvm-svn: 318920
The default limit is 1000000 but it can be configured with a cache
policy. The motivation is that some filesystems (notably ext4) have
a limit on the number of files that can be contained in a directory
(separate from the inode limit).
Differential Revision: https://reviews.llvm.org/D40327
llvm-svn: 318857
The MIPS GOT section has a number of local entries based on the number of pages
needed for output sections referenced by GOT page relocations. The number is
recorded in the DT_MIPS_LOCAL_GOTNO dynamic section tag. However, the dynamic tag
is added before assignAddresses has been called, meaning that any section size used
to calculate the value will not include size modifications caused by, for example,
linker scripts and thunks.
This change moves the calculation of DT_MIPS_LOCAL_GOTNO until writeTo, by which
time the output section sizes have been finalized.
Reviewers: ruiu, rafael
Differential Revision: https://reviews.llvm.org/D39493
llvm-svn: 318828
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
Summary:
I noticed that the reproducers files I was getting from building CheriBSD
didn't work because the --sysroot option was not being rewritten. I've
updated the test to also verify that the rewritten path matches uses a
FileCheck capature instead of a {{.+}} regex
Reviewers: ruiu
Reviewed By: ruiu
Subscribers: llvm-commits, emaste
Differential Revision: https://reviews.llvm.org/D40125
llvm-svn: 318656
Summary:
This matches the behaviour of ld.bfd:
https://sourceware.org/binutils/docs/ld/Options.html#Options
If scriptfile does not exist in the current directory, ld looks for it in
the directories specified by any preceding '-L' options. Multiple '-T'
options accumulate.
Reviewers: ruiu, grimar
Reviewed By: ruiu, grimar
Subscribers: emaste, llvm-commits
Differential Revision: https://reviews.llvm.org/D40129
llvm-svn: 318655
Summary:
The bug triggers when the following conditions are met:
- A thunk is created in a given input section S
- A linker script is specified
- There is at least one matcher in the linker script .text section output
that does not match any of the sections in the input files, before the matcher
that matches section S.
The issue was found when linking the FreeBSD kernel for MIPS when built
with -fPIC. Patch by Alfredo Mazzinghi.
Reviewers: ruiu, psmith, atanasyan
Reviewed By: ruiu
Subscribers: peter.smith, emaste, sdardis, krytarowski, llvm-commits
Differential Revision: https://reviews.llvm.org/D40174
llvm-svn: 318653
The comdat sections in these test cases do not comply with the COFF
specification, and link.exe rejects them. I plan to make a change to
how we handle comdat sections which would also cause us to reject them.
llvm-svn: 318637
It is private to llvm. Instead use llvm/Config/llvm-config.h and check
LLVM_ON_UNIX. That is the same guard that clang uses before including
unistd.h.
llvm-svn: 318558
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
This linker backend is still a work in progress but is
enough to link simple programs including linking against
library archives.
Differential Revision: https://reviews.llvm.org/D34851
llvm-svn: 318539
Recently we teached LLD to report line numbers for duplicate variables
definitions, though currently LLD is unable to do that for case when
strings are not built in .debug_info, but stored in .debug_str instead.
That is because out LLDDwarfObj does not handle .debug_str yet.
Patch fixes that.
Differential revision: https://reviews.llvm.org/D39542
llvm-svn: 318519
This fixes PR35223.
Here I enabled SHF_MERGE section content merging for -r like
we do for regular linking.
Differential revision: https://reviews.llvm.org/D40026
llvm-svn: 318516
Commit r318397 fixed the cache pruning interval which broke this test
as it was assuming that the cache pruning was always being
performed. Explicitly set prune interval to 0s to ensure this.
llvm-svn: 318426
Previously our relocations we rewrote were broken for that case.
We emited incorrect addend and broken relocation info field
because did not produce section symbol for mergeable synthetic sections.
Differential revision: https://reviews.llvm.org/D40070
llvm-svn: 318394
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
An output section can include elements from two input sections with
different sh_entsize. When that happens the output section itself
should not have a sh_entsize.
llvm-svn: 318311
No difference in practice other than having sh_entsize in the output.
This should simplify the patch for handling SHF_MERGE in -r.
Based on a patch by George Rimar.
llvm-svn: 318306
LLD already writes a build id if debug info is enabled.
Some projects set --pie-executable to avoid GNU ld bugs about stripping
base relocations from an executable when they actually are used.
Since -fixed:no is the default (and we don't support setting the
-fixed option via the MinGW frontend), we don't need to handle this.
--disable-auto-image-base is ignored just like --enable-auto-image-base
(as we ignore from before).
Differential Revision: https://reviews.llvm.org/D40031
llvm-svn: 318285
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
GNU ld doesn't seem to support --icf at all, but this was suggested
in D39885, and GNU gold seems to support it.
Differential Revision: https://reviews.llvm.org/D40019
llvm-svn: 318283
All of these are disabled by default in GNU ld, but enabled by default
in lld.
Disable dynamicbase by default since it potentially could cause
compatibility issues, but just ignore the others since the lld
default should be fine for most concievable cases.
Differential Revision: https://reviews.llvm.org/D40017
llvm-svn: 318281
In GNU ld, this option is only available on i386, not on x86_64
(where it's enabled by default with no option to disable it either).
Differential Revision: https://reviews.llvm.org/D40015
llvm-svn: 318280
Lnt is both a server and a set of script for benchmarking llvm.
I don't think it makes sense to use the scripts for lld since our
benchmarks are quite different.
The server on the other hand is very general and seems to work well
for tracking any quantities.
This patch adds a script to lld that can be used to run various
benchmarks and send the result to lnt.
The benchmarks are assumed to each be a response file in a
subdirectory. Each subdirectory can contain multiple response
files. That can be used to have a plain response.txt and a
response-icf.txt for example. The name of each benchmark is the
combination of the directory name and the "flavor": firefox-gc,
chromium-icf, etc.
For the first version the script uses perf and collects all the
metrics that a plain "perf stat" prints.
This script can then be used by a developer to test a patch or by a
bot to keep track of lld's performance.
llvm-svn: 318158
microMIPS symbols including microMIPS PLT records created for regular
symbols needs to be marked by STO_MIPS_MICROMIPS flag in a symbol table.
Additionally microMIPS entries in a dynamic symbol table should have
configured less-significant bit. That allows to escape teaching a
dynamic linker about microMIPS symbols.
llvm-svn: 318097
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
It is really hard to cover restarts in a debugger, SIGKILL or power
failures. I will try to handle them in a followup patch, but it will
not support all the systems lld has to run on.
RemoveFileOnSignal takes care of crashes.
So what is left is making sure all regular exits delete the file. This
patch does that by moving the buffer to error handling. That is a bit
of a hack, but seemed better than to generalize it to take a callback on
construction.
I will implement this on COFF on the next patch.
llvm-svn: 318060
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
I think the constract of this function is to remove a file in some way,
whether in background or in foreground. This patch makes sure that it
removes a given file.
Differential Revision: https://reviews.llvm.org/D39778
llvm-svn: 317663
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
It used to rename the file before removing it in a background thread.
A simpler way to delay the removal is simply to open the file.
Since this is a posix specific issue, simplify the windows
implementation.
llvm-svn: 317631
Rui Ueyama