Previously we did not support following:
foo = ~0xFF;
and had to add space before numeric value:
foo = ~ 0xFF
That was constistent with ld.bfd < 2.30, which shows:
script.txt:3: undefined symbol `~2' referenced in expression,
but inconsistent with gold.
It was fixed for ld.bfd 2.30 as well:
https://sourceware.org/bugzilla/show_bug.cgi?id=22267
Differential revision: https://reviews.llvm.org/D36508
llvm-svn: 315569
GNU ld automatically exports all symbols if no symbols have
been chosen to export via either def files or dllexport attributes.
The same behaviour can also be enabled via the GNU ld option
--export-all-symbols, in case some symbols are marked for export
via a def file or dllexport attribute.
The list of excluded symbols is from GNU ld, minus the
cygwin specific symbols.
Also add support for outputting the actual list of exported
symbols in a def file, as in the GNU ld option --output-def.
These options in GNU ld are documented in
https://sourceware.org/binutils/docs/ld/WIN32.html.
This currently exports all symbols from object files pulled in
from libmingw32 and libmingwex and other static libraries
that are linked in.
Differential Revision: https://reviews.llvm.org/D38760
llvm-svn: 315562
This is implemented in the same way as the other ADDR32NB relocations
for ARM and X64.
Differential Revision: https://reviews.llvm.org/D38815
llvm-svn: 315561
A section was passed to getRelExpr just to create an error message.
But if there's an invalid relocation, we would eventually report it
in relocateOne. So we don't have to pass a section to getRelExpr.
llvm-svn: 315552
This is PR34546.
Currently LLD creates output sections even if it has no input sections,
but its command contains an assignment.
Committed code just assigns the same flag that was used in previous
live section.
That does not work sometimes. For example if we have following script:
.ARM.exidx : { *(.ARM.exidx*) }
.foo : { _foo = 0; } }
Then first section has SHF_LINK_ORDER flag. But section foo should not.
That was a reason of crash in OutputSection::finalize(). LLD tried to calculate
Link value, calling front() on empty input sections list.
We should only keep access flags and omit all others when creating such sections.
Patch fixes the crash observed.
Differential revision: https://reviews.llvm.org/D37736
llvm-svn: 315441
Fixes PR34306.
This is because it usually results in more compact code, and because
there are also known code generation bugs when using the PIC model
(see bug).
Based on a patch by Carlo Kok.
Differential Revision: https://reviews.llvm.org/D38769
llvm-svn: 315400
We just don't need one with the current setup.
We only error on undefined references that are used by some
relocation.
If we managed to relax all uses of __tls_get_addr, no relocation uses
it and we don't produce an error.
This is less code and fixes the case were we fail to relax. Before we
would produce a broken output, but now we produce an error.
llvm-svn: 315334
When parsing linker scripts, LLD previously started with a '.' value of 0,
regardless of the internal default image base for the target, and regardless of
switches such as --image-base. It seems reasonable to use a different image base
value when using linker scripts and --image-base is specified, since otherwise the
switch has no effect. This change does this, as well as removing unnecessary
initialisation of Dot where it is not used.
The default image base should not be used when processing linker
scripts, because this will change the behaviour for existing linker script users,
and potentially result in invalid output being produced, as a subsequent assignment
to Dot could move the location counter backwards. Instead, we maintain the existing
behaviour of starting from 0 if --image-base is not specified.
Reviewers: ruiu
Differential Revision: https://reviews.llvm.org/D38360
llvm-svn: 315293
When findOrphanPos does the reverse search to find the OutputSection
preceding the orphan's insertion point, look for a live OutputSection
and ignore "dead" OutputSection's. This matches the behaviour of the
forward search performed earlier in this function.
Added test which without the above fix fails as a result of an orphan
executable section being incorrectly placed in a non-executable segment.
Differential Review: https://reviews.llvm.org/D38690
llvm-svn: 315292
I believe the reason why we used warn() instead of error() to report
undefined symbols is because the older implementation of error() exitted
immediately. Here, we want to find as many undefined symbols as we can,
so I chose to use warn() instead of error().
Now error() does not exit immediately, so it doesn't make sense to keep
them as warnings.
Differential Revision: https://reviews.llvm.org/D38652
llvm-svn: 315131
I hadn't synced past the change that changed the default hash style
to --hash-style=both, so my test had the symbols in the wrong order.
llvm-svn: 315119
Dynamic lists in an executable are additive, not restrictive, so we
must continue to export preempted symbols even with a dynamic list.
This fixes sanitizer interception of libc symbols (and should also fix
symbol preemption by users of sanitizers).
Differential Revision: https://reviews.llvm.org/D38647
llvm-svn: 315114
Before this patch we would copy foo into real_foo and wrap_foo into
foo. The net result is that __wrap_foo shows up twice in the symbol
table.
With this patch we:
* save a copy of __real_foo before copying foo.
* drop one of the __wrap_foo from the symbol table.
* if __real_foo was not undefined, add a *new* symbol with that content to
the symbol table.
The net result is that
Anything using foo now uses __wrap_foo
Anything using __real_foo now uses foo.
Anything using __wrap_foo still does.
And the symbol table has foo, __wrap_foo and __real_foo (if defined).
Which I think is the desired behavior.
llvm-svn: 315097
This addresses two sources of inconsistency in test configuration
files.
1. Substitution boundaries. Previously you would specify a
substitution, such as 'lli', and then additionally a set
of characters that should fail to match before and after
the tool. This was used, for example, so that matches that
are parts of full paths would not be replaced. But not all
tools did this, and those that did would often re-invent
the set of characters themselves, leading to inconsistency.
Now, every tool substitution defaults to using a sane set
of reasonable defaults and you have to explicitly opt out
of it. This actually fixed a few latent bugs that were
never being surfaced, but only on accident.
2. There was no standard way for the system to decide how to
locate a tool. Sometimes you have an explicit path, sometimes
we would search for it and build up a path ourselves, and
sometimes we would build up a full command line. Furthermore,
there was no standardized way to handle missing tools. Do we
warn, fail, ignore, etc? All of this is now encapsulated in
the ToolSubst class. You either specify an exact command to
run, or an instance of FindTool('<tool-name>') and everything
else just works. Furthermore, you can specify an action to
take if the tool cannot be resolved.
Differential Revision: https://reviews.llvm.org/D38565
llvm-svn: 315085
Summary:
These are 16 bit relocations and not part of a HI/LO pair so we need to
check that they don't overflow.
Reviewers: atanasyan
Reviewed By: atanasyan
Subscribers: ruiu, llvm-commits, emaste, sdardis
Tags: #lld
Differential Revision: https://reviews.llvm.org/D38614
llvm-svn: 315073
LLD produces broken .dynamic section when --no-rosegment and at least
one of following options is present:
1) -z rodynamic is given.
2) MIPS target.
That happens because code that writes .dynamic assumes target buffer
is zero-filled, what can be not true after LLD fills it with trap
instructions. With one of two options above, .dynamic becomes
SHF_ALLOC section, so can be affected.
Differential revision: https://reviews.llvm.org/D38580
llvm-svn: 315054
We produce broken output currently.
Code that writes .dynsym assumes output buffer is zero-filled,
though that is not always true. When --no-rosegment is given,
buffer can be filled with trap instructions. Patch fixes the issue.
It is relative with PR34705.
Differential revision: https://reviews.llvm.org/D38579
llvm-svn: 315053
Its PR34712,
GNU linkers recently changed default values to "both" of "sysv".
Patch do the same for all targets except MIPS, where .gnu.hash
section is not yet supported.
Code suggested by Rui Ueyama.
Differential revision: https://reviews.llvm.org/D38407
llvm-svn: 315051
Summary:
We were crashing when linking telnetd in FreeBSD because lld was emitting
corrupted output files for --norosegment. In this file the version index of some symbols
was set to 9 but lld only found 8 version definitions.
I am not sure how to create a minimal .so file that also exposes this behaviour so I just added the one that initially caused the error to Inputs/
This partially addresses https://bugs.llvm.org/show_bug.cgi?id=34705
Reviewers: ruiu, rafael, pcc, grimar
Reviewed By: ruiu
Subscribers: emaste, krytarowski
Tags: #lld
Differential Revision: https://reviews.llvm.org/D38397
llvm-svn: 315036
Summary:
We were crashing when linking telnetd in FreeBSD because lld was emitting
corrupted output files for --norosegment. In this file the version index of some symbols
was set to 9 but lld only found 8 version definitions.
I am not sure how to create a minimal .so file that also exposes this behaviour so I just added the one that initially caused the error to Inputs/
This partially addresses https://bugs.llvm.org/show_bug.cgi?id=34705
Reviewers: ruiu, rafael, pcc, grimar
Reviewed By: ruiu
Subscribers: emaste, krytarowski
Tags: #lld
Differential Revision: https://reviews.llvm.org/D38397
llvm-svn: 315035
We have verneed1.so, verneed2.so files and verneed.so.sh script
to produce them. They were committed long time ago when LLD
was not yet able to produce some sections for versioning
(".gnu.version_r" I think).
There is no point to have them as binaries anymore. Patch
creates asm inputs instead based on verneed.so.sh content.
Differential revision: https://reviews.llvm.org/D38505
llvm-svn: 314889
When reporting a symbol conflict, LLD parses the debug info to report
source location information. Sections have not been decompressed at this
point, so if an object file contains zlib compressed debug info, LLD
ends up passing this compressed debug info to the DWARF parser, which
causes debug info parsing failures and can trigger assertions in the
parser (as the test case demonstrates).
Decompress debug sections when constructing the LLDDwarfObj to avoid
this issue. This doesn't handle GNU-style compressed debug info sections
(.zdebug_*), which at present are simply ignored by LLDDwarfObj; those
can be done in a follow-up.
Differential Revision: https://reviews.llvm.org/D38491
llvm-svn: 314866
If symbol has the STO_MIPS_MICROMIPS flag and requires a thunk to perform
call PIC from non-PIC functions, we need to generate a thunk with microMIPS
code.
llvm-svn: 314797
Currently LLD calls the `isMicroMips` routine to determine type of PLT entries
needs to be generated: regular or microMIPS. This routine checks ELF
header flags in the `FirstObj` to retrieve type of linked object files.
So if the first file does not contain microMIPS code, LLD will generate
PLT entries with regular (non-microMIPS) code only.
Ideally, if a PLT entry is referenced by microMIPS code only this entry
should contain microMIPS code, if a PLT entry is referenced by regular
code this entry should contain regular code. In a "mixed" case the PLT
entry can be either microMIPS or regular, but each "cross-mode-call" has
additional cost.
It's rather difficult to implement this ideal solution. But we can
assume that if there is an input object file with microMIPS code, the
most part of the code is microMIPS too. So we need to deduce type of PLT
entries based on finally calculated ELF header flags and do not check
only the first input object file.
This change implements this.
- The `getMipsEFlags` renamed to the `calcMipsEFlags`. The function
called from the `LinkerDriver::link`. Result is stored in
the Configuration::MipsEFlags field.
- The `isMicroMips` and `isMipsR6` routines access the `MipsEFlags`
field to get and check calculated ELF flags.
- New types of PLT records created when necessary.
Differential revision: https://reviews.llvm.org/D37747
llvm-svn: 314675
The result of hash_value(StringRef) depends on sizeof(size_t).
That causes lld to create different mergeable table contents on
32-bit machines.
This patch is to use xxHash64 so that we get the same hash values
on 32-bit machines.
llvm-svn: 314603
String merging is one of the most time-consuming functions in lld.
This patch parallelize it to speed it up. On my 2-socket 20-core
40-threads Xeon E5-2680 @ 2.8 GHz machine, this patch shorten the
clang debug build link time from 7.11s to 5.16s. It's a 27%
improvement and actually pretty noticeable. In this test condition,
lld is now 4x faster than gold.
Differential Revision: https://reviews.llvm.org/D38266
llvm-svn: 314588
This would have found the issues with r313697.
The problem was that that commit mixed the content of different
.eh_frame sections. Unfortunately we had no tests looking inside the
fdes.
llvm-svn: 314433
It was introduced by me in D37059.
Comment was saying that Weak binding is incorrect
for 'foo' symbol and that should be true for symbol in final output.
But at that place LTO temporarily file was checked,
where Weak binding for 'foo' is fine as LTO changes binding for
'LinkerRedefined' symbols internally to prevent IPO.
Binding for 'foo' in final output is correctly set to Global
and that tested just few lines below in the same testcase.
llvm-svn: 314204
When -verbose is specified, patch outputs names of each input orphan section
assigned to output.
Differential revision: https://reviews.llvm.org/D37517
llvm-svn: 314098
Previously when BC file had global variable that was accessed from script,
it was optimized away or inlined by IPO.
In this patch I add symbols at left side of assignment expression as LinkerRedefined,
what prevents optimization for them.
Differential revision: https://reviews.llvm.org/D37059
llvm-svn: 314097
Previously, we had two levels of hash table lookup. The first hash
lookup uses CachedHashStringRefs as keys and returns offsets in string
table. Then, we did the second hash table lookup to obtain GdbSymbol
pointers. But we can directly map strings to GDbSymbols.
One test file is updated in this patch because we no longer have a '\0'
byte at the start of the string pool, which was automatically inserted
by StringTableBuilder.
This patch speeds up Clang debug build (with -gdb-index) link time by
0.3 seconds.
llvm-svn: 314092
There were two issues, one Python 3 specific related to Unicode,
and another which is that the tool substitution for lld no longer
rejected matches where a / preceded the tool name.
llvm-svn: 313928
George Rimar