Summary:
Currently the test only checks behaviour for weak function symbols.
Should be good to merge straight away?
Reviewers: sbc100
Reviewed By: sbc100
Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D41449
llvm-svn: 321308
In this case we are calling a function pointer which
a type that doesn't otherwise exist in the code.
Clearly this code can't would trap if it was ever
called (because there is not such function that
the pointer can resolve to).
But it should valid and compile and link and validation
time.
llvm-svn: 321134
This change add support for init functions in the linking
section, but only in -r/--relocatable mode.
Differential Revision: https://reviews.llvm.org/D41375
llvm-svn: 321088
A more efficient PLT sequence can be used when the distance between the
.plt and the end of the .plt.got is less than 128 Megabytes, which is
frequently true. We fall back to the old sequence when the offset is larger
than 128 Megabytes. This gives us an alternative to forcing the longer
entries with --long-plt as we gracefully fall back to it as needed.
See ELF for the ARM Architecture Appendix A for details of the PLT sequence.
Differential Revision: https://reviews.llvm.org/D41246
llvm-svn: 320987
Summary:
1. Use stream 0 only for combined module. Previously if combined module was not
processes ThinLTO used the stream for own output. However small changes in input,
could trigger combined module and shuffle outputs making life of llvm::LTO harder.
2. Always process combined module and write output to stream 0. Processing empty
combined module is cheap and allows llvm::LTO users to avoid implementing processing
which is already done in llvm::LTO.
Subscribers: mehdi_amini, inglorion, eraman, hiraditya
Differential Revision: https://reviews.llvm.org/D41267
llvm-svn: 320905
/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 only need to exceed 128 Megabytes to provoke the generation of a range
extension thunk. This brings the file size down to just over 128 Megabytes.
llvm-svn: 320821
I noticed that the continue this patch deletes was not tested. Trying
to add a test I realized that we never put a VER_NDX_LOCAL symbol in
the dynamic symbol table. There doesn't seem to be any reason for a
linker to use VER_NDX_LOCAL for a defined shared symbol.
llvm-svn: 320817
The ARM.exidx section contains a table of 8-byte entries with the first
word of each entry an offset to the function it describes and the second
word instructions for unwinding if an exception is thrown from that
function. The SHF_LINK_ORDER processing will order the table in ascending
order of the functions described by the exception table entries. As the
address range of an exception table entry is terminated by the next table
entry, it is possible to merge consecutive table entries that have
identical unwind instructions.
For this implementation we define a table entry to be identical if:
- Both entries are the special EXIDX_CANTUNWIND.
- Both entries have the same inline unwind instructions.
We do not attempt to establish if table entries that are references to
.ARM.extab sections are identical.
This implementation works at a granularity of a single .ARM.exidx
InputSection. If all entries in the InputSection are identical to the
previous table entry we can remove the InputSection. A more sophisticated
but more complex implementation would rewrite InputSection contents so that
duplicates within a .ARM.exidx InputSection can be merged.
Differential Revision: https://reviews.llvm.org/D40967
llvm-svn: 320803
This patch provides the mechanism to fix instances of the instruction
sequence that may trigger the cortex-a53 843419 erratum. The fix is
provided by an alternative instruction sequence to remove one of the
erratum conditions. To reach this alternative instruction sequence we
replace the original instruction with a branch to the alternative
sequence. The alternative sequence is responsible for branching back to
the original.
As there is only erratum to fix the implementation is specific to
AArch64 and the specific erratum conditions. It should be generalizable
to other targets and erratum if needed.
Differential Revision: https://reviews.llvm.org/D36749
llvm-svn: 320800
Windows paths have colons in them, so the regex will fail there. Just
match for any character; the rest of the message will restrict the match
to the path anyway.
llvm-svn: 320793
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
Specifically, libwidevinecdm.so in Chrome has such bad symbol.
It seems the BFD linker handles them as local symbols, so instead
of inserting them to the symbol table, we should skip them too.
Differential Revision: https://reviews.llvm.org/D41257
llvm-svn: 320770
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
We might crash in 'ARMExidxSentinelSection::writeTo()' because it expected
the sentinel entry to be put in the same 'InputSectionDescription' as
the last real entry. This assumption fails if the last output section command
for .ARM.exidx is anything but an input section description, because in this
case 'OutputSection::addSection()' creates a new 'InputSectionDescription'.
Differential Revision: https://reviews.llvm.org/D41105
llvm-svn: 320668
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
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
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
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
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
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
This line was mistakenly deleted in rL319813
Add a test for stackpointer relocations.
Differential Revision: https://reviews.llvm.org/D40847
llvm-svn: 319828
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
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
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
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
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
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
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
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
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
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
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
After ObjectYAML learnt the proper enum names for ARMNT/ARM64
relocations, it no longer accepts the numerical values.
This fixes LLD tests after SVN r317459 in LLVM.
llvm-svn: 317460
Common symbols are now represented with a DefinedRegular that points
to a BssSection, even during symbol resolution.
Differential Revision: https://reviews.llvm.org/D39666
llvm-svn: 317447
Currently LLD tries to use information about functions and variables location
taking it from debug sections. When --strip-* is given we discard such sections
and that breaks error reporting.
Patch stops discarding such sections and just removes them from InputSections list.
Differential revision: https://reviews.llvm.org/D39550
llvm-svn: 317405
When findMemoryRegion do search to find a region for output section it
iterates over MemoryRegions which is DenseMap and so does not
guarantee iteration in insertion order. As a result selected region depends
on its name and not on its definition position
Testcase shows the issue, patch fixes it. Behavior after applying the patch
seems consistent with bfd.
Differential revision: https://reviews.llvm.org/D39544
llvm-svn: 317307
Currently we do not strip .zdebug_*, what looks wrong.
Also this simplifies the testcase we have for this options.
Differential revision: https://reviews.llvm.org/D39552
llvm-svn: 317306
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: 317305
This is PR34826.
Currently LLD is unable to report line number when reporting
duplicate declaration of some variable.
That happens because for extracting line information we always use
.debug_line section content which describes mapping from machine
instructions to source file locations, what does not help for
variables as does not describe them.
In this patch I am taking the approproate information about
variables locations from the .debug_info section.
Differential revision: https://reviews.llvm.org/D38721
llvm-svn: 317080
Summary:
**Problem**
`--exclude-libs` does not work for static libraries affected by the `--whole-archive` option.
**Description**
`--exclude-libs` creates a list of static library paths and does library lookups in this list.
`--whole-archive` splits the static libraries that follow it into separate objects. As a result, lld no longer sees static libraries among linked files and does no `--exclude-libs` lookups.
**Solution**
The proposed solution is to make `--exclude-libs` consider object files too. When lld finds an object file it checks whether this file originates from an archive and, if so, looks the archive up in the `--exclude-libs` list.
Reviewers: ruiu, rafael
Reviewed By: ruiu
Subscribers: asl, ikudrin, llvm-commits, emaste
Tags: #lld
Differential Revision: https://reviews.llvm.org/D39353
llvm-svn: 316998
edata needs to be set to the end of the last mapped initialized
section. We were previously mishandling the case where there were no
non-mapped sections by setting it to the end of the last section in
the output file.
Differential Revision: https://reviews.llvm.org/D39399
llvm-svn: 316877
I don't think we have to aim for precise bug compatibility.
We can return a nullptr if a section is consumed by the linker, and
the rest should naturally work.
llvm-svn: 316817
The Android relocation packing format is a more compact
format for dynamic relocations in executables and DSOs
that is based on delta encoding and SLEBs. An overview
of the format can be found in the Android source code:
https://android.googlesource.com/platform/bionic/+/refs/heads/master/tools/relocation_packer/src/delta_encoder.h
This patch implements relocation packing using that format.
This implementation uses a more intelligent algorithm for compressing
relative relocations than Android's own relocation packer. As a
result it can generally create smaller relocation sections than
that packer. If I link Chromium for Android targeting ARM32 I get a
.rel.dyn of size 174693 bytes, as compared to 371832 bytes with gold
and the Android packer.
Differential Revision: https://reviews.llvm.org/D39152
llvm-svn: 316775
This is for PR34852.
GCC 8.0 or earlier have a bug that it emits R_386_GOTPC relocations
against _GLOBAL_OFFSET_TABLE for .debug_info. The bug seems to have
been fixed in 2017: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82630,
but we do not want LLD to report errors for such inputs.
In this patch we ignore such relocations.
Differential revision: https://reviews.llvm.org/D38625
llvm-svn: 316761
Sam Clegg