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
debuginfo-tests has need to reuse a lot of common configuration
from clang and lld, and in general it seems like all of the
projects which are tightly coupled (e.g. lld, clang, llvm, lldb,
etc) can benefit from knowing about one other. For example,
lldb needs to know various things about how to run clang in its
test suite. Since there's a lot of common substitutions and
operations that need to be shared among projects, sinking this
up into LLVM makes sense.
In addition, this patch introduces a function add_tool_substitution
which handles all the dirty intricacies of matching tool names
which was previously copied around the various config files. This
is now a simple straightforward interface which is hard to mess
up.
Differential Revision: https://reviews.llvm.org/D37944
llvm-svn: 313919
For ARM thunks, the `movt` half of the relocation was using an incorrect
offset (it was off by 4 bytes). The original intent seems to have been
for the offset to have been relative to the current instruction, in
which case the difference of 4 makes sense. As the code stands, however,
the offset is always calculated relative to the start of the thunk
(`P`), and so the `movw` and `movt` halves should use the same offset.
This requires a very particular offset between the thunk and its target
to be triggered, and it results in the `movt` half of the relocation
being off-by-one.
The tests here use ARM-Thumb interworking thunks, since those are the
only ARM thunks currently implemented. I actually encountered this with
a range extension thunk (having Peter's patches cherry-picked locally),
but the underlying issue is identical.
Differential Revision: https://reviews.llvm.org/D38112
llvm-svn: 313915
This follows in line with a previous patch of renaming LLVM's.
Working on these files is difficult in certain operating systems
and/or environments that don't like handling python code with a
non .py file extension.
llvm-svn: 313892
This patch goes back to considering ForceAbsolute in moveAbsRight, but
only if the second argument is not already absolute.
With this we can handle "foo + ABSOLUTE(foo)" and "ABSOLUTE(foo) + foo".
llvm-svn: 313800
The idea of this function is to simplify the implementation of binary
operators like add.
A value might be absolute because of an ABSOLUTE expression, but it
still depends on the value of a section and we might not be able to
evaluate it early. We should keep such values on the LHS, so that we
can delay the evaluation.
We can now handle both "1 + ABSOLUTE(foo)" and "ABSOLUTE(foo) + 1".
llvm-svn: 313794
The previous logic was to try to detect if a linker script defined _gp
by checking !ElfSym::MipsGp->Value. That doesn't work in all cases as
the assigned value can be 0.
We now just always defined it Writer.cpp and always overwrite it
afterwards if needed.
llvm-svn: 313788
Normally to find the offset of a value in a section, we have to
compute the value since the alignment is defined on the final address.
If the alignment is trivial, we can skip the value computation. This
allows us to know the offset even in cases where we cannot yet know
the value.
llvm-svn: 313777
We try to evaluate expressions early when possible, but it is not
possible to evaluate them early if they are based on a section.
Before we would get this wrong on ABSOLUTE expressions.
llvm-svn: 313764
Sections are limited to 4 GiB. Error out early if a section exceeds this
size, rather than overflowing the section size and getting confusing
assertion failures/segfaults later.
Differential Revision: https://reviews.llvm.org/D38005
llvm-svn: 313699
Given a linker script that ends in
.some_sec { ...} ;
__stack_start = .;
. = . + 0x2000;
__stack_end = .;
lld would put orphan sections like .comment before __stack_end,
corrupting the intended meaning.
The reason we don't normally move orphans past assignments to . is to
avoid breaking
rx_sec : { *(rx_sec) }
. = ALIGN(0x1000);
/* The RW PT_LOAD starts here*/
but in this case, there is nothing after and it seems safer to put the
orphan section last. This seems to match bfd's behavior and is
convenient for writing linker scripts that care about the layout of
SHF_ALLOC sections, but not of any non SHF_ALLOC sections.
llvm-svn: 313646
This is PR34506.
Imagine we have 2 sections the same name but different COMDAT groups:
.section .foo,"axG",@progbits,bar,comdat
.section .foo,"axG",@progbits,zed,comdat
When linking relocatable we do not merge SHT_GROUP sections. But still would merge
both input sections .foo into single output section .foo.
As a result we will have 2 different SHT_GROUPs containing the same section, what
is wrong.
Patch fixes the issue, preventing merging SHF_GROUP sections with any others.
Differential revision: https://reviews.llvm.org/D37574
llvm-svn: 313621
We crashed when --emit-relocs was used
and relocated section was collected by GC.
Differential revision: https://reviews.llvm.org/D37561
llvm-svn: 313620
r303378 was submitted because r303374 (Merge IAT and ILT) made lld's
output incompatible with the Binding feature. Now that r303374 was
reverted, we do not need to keep this change.
Pointed out by pcc.
llvm-svn: 313414
This is a resubmission of r313270. It broke standalone builds of
compiler-rt because we were not correctly generating the llvm-lit
script in the standalone build directory.
The fixes incorporated here attempt to find llvm/utils/llvm-lit
from the source tree returned by llvm-config. If present, it
will generate llvm-lit into the output directory. Regardless,
the user can specify -DLLVM_EXTERNAL_LIT to point to a specific
lit.py on their file system. This supports the use case of
someone installing lit via a package manager. If it cannot find
a source tree, and -DLLVM_EXTERNAL_LIT is either unspecified or
invalid, then we print a warning that tests will not be able
to run.
Differential Revision: https://reviews.llvm.org/D37756
llvm-svn: 313407
This fixes pr34301.
As the bug points out, we want to keep some relocations with undefined
weak symbols. This means that we cannot always claim that these
symbols are not preemptible as we do now.
Unfortunately, we cannot also just always claim that they are
preemptible. Doing so would, for example, cause us to try to create a
plt entry when we don't even have a dynamic symbol table.
What almost works is to say that weak undefined symbols are
preemptible if and only if we have a dynamic symbol table. Almost
because we don't want to fail the build trying to create a copy
relocation to a weak undefined.
llvm-svn: 313372
This patch is still breaking several multi-stage compiler-rt bots.
I already know what the fix is, but I want to get the bots green
for now and then try re-applying in the morning.
llvm-svn: 313335
_gp points to a position in the file, so it is not really absolute. It
is also simpler to not force it to be absolute, so if there is no
strong ABI requirement we should not do it.
llvm-svn: 313333
GNU ld manual says that multi-letter long option can be prefixed with
either -- or -. Therefore, we should accept not only --subsystem but
also -subsystem, for example.
There is one exception. If an option starts with "o", it should only be
prefixed with -- to avoid ambiguity with -o<filename> option.
Differential Revision: https://reviews.llvm.org/D37825
llvm-svn: 313286
This patch simplifies LLVM's lit infrastructure by enforcing an ordering
that a site config is always run before a source-tree config.
A significant amount of the complexity from lit config files arises from
the fact that inside of a source-tree config file, we don't yet know if
the site config has been run. However it is *always* required to run
a site config first, because it passes various variables down through
CMake that the main config depends on. As a result, every config
file has to do a bunch of magic to try to reverse-engineer the location
of the site config file if they detect (heuristically) that the site
config file has not yet been run.
This patch solves the problem by emitting a mapping from source tree
config file to binary tree site config file in llvm-lit.py. Then, during
discovery when we find a config file, we check to see if we have a
target mapping for it, and if so we use that instead.
This mechanism is generic enough that it does not affect external users
of lit. They will just not have a config mapping defined, and everything
will work as normal.
On the other hand, for us it allows us to make many simplifications:
* We are guaranteed that a site config will be executed first
* Inside of a main config, we no longer have to assume that attributes
might not be present and use getattr everywhere.
* We no longer have to pass parameters such as --param llvm_site_config=<path>
on the command line.
* It is future-proof, meaning you don't have to edit llvm-lit.in to add
support for new projects.
* All of the duplicated logic of trying various fallback mechanisms of
finding a site config from the main config are now gone.
One potentially noteworthy thing that was required to implement this
change is that whereas the ninja check targets previously used the first
method to spawn lit, they now use the second. In particular, you can no
longer run lit.py against the source tree while specifying the various
`foo_site_config=<path>` parameters. Instead, you need to run
llvm-lit.py.
Differential Revision: https://reviews.llvm.org/D37756
llvm-svn: 313270
This is how the flag is documented in GNU binutils ld; -Bstatic
only applies to -l options after it, until the next -Bdynamic.
Differential Revision: https://reviews.llvm.org/D37794
llvm-svn: 313175
In MinGW configurations (GCC, or clang with a *-windows-gnu target),
the -export directives in the object file contains the undecorated
symbol name, while it is decorated in MSVC configurations. (On the
command line, link.exe takes an undecorated symbol name for the
-export argument though.)
Differential Revision: https://reviews.llvm.org/D37772
llvm-svn: 313174
This should fix the lto bootstrap.
It is somewhat hard to remember about lazy symbols deep down in the
link. It might be worth it replacing them with undefined symbols once
we are done adding files.
llvm-svn: 313103
https://reviews.llvm.org/rL312796 meant that references to garbage collected common symbols would cause a segfault.
This change fixes the behaviour for references to stripped common symbols.
Differential Revision: https://reviews.llvm.org/D37718
llvm-svn: 313086
On i386, the --entry parameter to GNU ld is supposed to be a decorated
symbol name, while it is an undecorated name in link.exe.
Differential Revision: https://reviews.llvm.org/D37710
llvm-svn: 313066
Rui Ueyama