In https://reviews.llvm.org/D137982 we found that on Mach-O private
aliases could trigger an assert in lld when the aliasee was a
weak_def_can_be_hidden symbol.
This appears to be incorrect, and should be allowed in Mach-O.
Disallowing this behavior is also inconsistent with how ld64 handles
a private alias to weak_def_can_be_hidden symbols.
This patch removes the assert and tests that LLD handles such aliases
gracefully.
Reviewed By: #lld-macho, int3
Differential Revision: https://reviews.llvm.org/D141082
We can technically handle them, but since they shouldn't come up in any
real-world programs (since ld64 dedups strings unconditionally), there's
no reason to support them.
It's a thoroughly untested code path too -- as evidenced by the fact
that the only test this change breaks is one that verifies that we
reject relocations when dedup'ing. There is no test that covers the case
where we handle relocations in cstring sections when dedup is disabled.
Reviewed By: #lld-macho, oontvoo, keith, thakis
Differential Revision: https://reviews.llvm.org/D141025
Revert "Fix lldb option handling since e953ae5bbc (part 2)"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4"
GCC build hangs on this bot https://lab.llvm.org/buildbot/#/builders/37/builds/19104
compiling CMakeFiles/obj.clangBasic.dir/Targets/AArch64.cpp.d
The bot uses GNU 11.3.0, but I can reproduce locally with gcc (Debian 12.2.0-3) 12.2.0.
This reverts commit caa713559b.
This reverts commit 06b90e2e9c.
This reverts commit e953ae5bbc.
Errors / warnings that originate from a particular file should be of the
form `$file: $message`.
Reviewed By: #lld-macho, keith
Differential Revision: https://reviews.llvm.org/D140634
This will enable us to re-land {D139069}.
The issue with the original diff was that we were folding all
private-label symbols. We were not merging the symbol flags during this
folding; instead we just made all references to the folded symbol point
to its aliasee. This caused some flags to be incorrectly discarded. This
surfaced as code that was incorrectly stripped due to LLD dropping the
`.no_dead_strip` flag.
This diff fixes things by only folding flag-less private-label aliases.
Most (maybe all) of the `ltmp<N>` symbols that are generated by the MC
aarch64 backend are flag-less, so this conservative folding behavior
does the job.
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D140606
By default ld64 ignores invalid LC_LINKER_OPTIONS unless the link fails,
in which case it prints a warning. Originally lld chose to be strict
about these, but it has uncovered that many of these exist in open
source projects today, since before developers never would have noticed
this issue. In order to make adoption of lld easier, this mirrors ld64's
behavior, while also adding a `--strict-auto-link-options` flag if
projects want to audit their libraries for these invalid options.
More discussion on https://reviews.llvm.org/D140225
Fixes https://github.com/llvm/llvm-project/issues/59627
Differential Revision: https://reviews.llvm.org/D140491
Previously by default, when not using `--ifc=`, lld would not
deduplicate string literals. This reveals reliance on undefined behavior
where string literal addresses are compared instead of using string
equality checks. While ideally you would be able to easily identify and
eliminate the reliance on this UB, this can be difficult, especially for
third party code, and increases the friction and risk of users migrating
to lld. This flips the default to deduplicate strings unless
`--no-deduplicate-strings` is passed, matching ld64's behavior.
Differential Revision: https://reviews.llvm.org/D140517
We now handle the GOT, TLV, and stubs/lazy pointer sections.
Reviewed By: #lld-macho, thevinster, thakis
Differential Revision: https://reviews.llvm.org/D139762
This is a fairly large changeset, but it can be broken into a few
pieces:
- `llvm/Support/*TargetParser*` are all moved from the LLVM Support
component into a new LLVM Component called "TargetParser". This
potentially enables using tablegen to maintain this information, as
is shown in https://reviews.llvm.org/D137517. This cannot currently
be done, as llvm-tblgen relies on LLVM's Support component.
- This also moves two files from Support which use and depend on
information in the TargetParser:
- `llvm/Support/Host.{h,cpp}` which contains functions for inspecting
the current Host machine for info about it, primarily to support
getting the host triple, but also for `-mcpu=native` support in e.g.
Clang. This is fairly tightly intertwined with the information in
`X86TargetParser.h`, so keeping them in the same component makes
sense.
- `llvm/ADT/Triple.h` and `llvm/Support/Triple.cpp`, which contains
the target triple parser and representation. This is very intertwined
with the Arm target parser, because the arm architecture version
appears in canonical triples on arm platforms.
- I moved the relevant unittests to their own directory.
And so, we end up with a single component that has all the information
about the following, which to me seems like a unified component:
- Triples that LLVM Knows about
- Architecture names and CPUs that LLVM knows about
- CPU detection logic for LLVM
Given this, I have also moved `RISCVISAInfo.h` into this component, as
it seems to me to be part of that same set of functionality.
If you get link errors in your components after this patch, you likely
need to add TargetParser into LLVM_LINK_COMPONENTS in CMake.
Differential Revision: https://reviews.llvm.org/D137838
This reverts commit 09c5aab7f8.
New changes:
Temporarily skip checking the output bundle's cpu/cpu-subtype
Suspected there's a bug in selecting targets which caused the produced bundle
to be arm64 bundle (even though it was specifically linked with -arch x86_64).
The current test that link succeeded should be sufficient, because
it would have failed with "unable to find matching tagets" prior to this patch.
Differential Revision: https://reviews.llvm.org/D139572
This reverts commit 52a118d08f.
New changes:
Fix tests to dump both slices in the fat-archive because otool
isn't deterministic about which slice it prints across different archs.
(It printed x86 on x86 machines but arm64 on arm64, this was why
the test failed on arm64)
Differential Revision: https://reviews.llvm.org/D139572
We only want to rewrite paths to files that the linker looks up. Files
under RPATH are looked up at runtime by dyld.
Reviewed By: #lld-macho, keith
Differential Revision: https://reviews.llvm.org/D140167
This reverts commit 66692c822a.
New changes:
- update test to require aarch64
- update test to not hard-code cpu[sub] type values (since they could change)
- update test to temporarily skip windows (because llvm-mc on windows doesn't seem to work with triple arm64-apple-macos)
Differential Revision: https://reviews.llvm.org/D139572
With newer versions of ld64 it generates an adhoc signature by default
for all arm64 simulator targets. This default is especially important
for unit test targets that rarely have custom codesigning requirements
but otherwise won't run on arm64 macs.
Differential Revision: https://reviews.llvm.org/D139672
I tried `-undefined suppress` without `-flat_namespace`.
lld printed `'-undefined suppress' only valid with '-flat_namespace'`
followed by many many screenfuls of error messages about undefined
symbols, making the original diag hard to see.
This is probably the common case when using `-undefined`, so let's
just abort the link immediately when there's an invalid `-undefined`
arg.
Differential Revision: https://reviews.llvm.org/D139559
The test added in https://reviews.llvm.org/D137368 has been failing
on our 32 bit arm bots:
https://lab.llvm.org/buildbot/#/builders/178/builds/3460
You get this for the strings:
<<dead>> 0x883255000000003 [ 10] literal string: Hello, it's me
Instead of the expected:
<<dead>> 0x0000000F [ 3] literal string: Hello, it's me
This is because unlike symbols whose size is a uint64_t, strings
use a StringRef whose size is size_t. size_t changes size between
32 and 64 bit platforms.
This fixes the test by using %z to print the size of the strings,
this works for 32 and 64 bit.
This was causing an uncaught exception issue in one of our programs. The
issue was fairly subtle / rare as it required two identical LSDAs that were
referenced by a pair of non-identical compact unwind encodings.
Reviewed By: #lld-macho, smeenai
Differential Revision: https://reviews.llvm.org/D139269
Fixes#59162. The test has a comment explaining what's going on.
See also Symbol::extract() in lld/ELF/Symbols.cpp.
The included test sadly also passes if I pass just bd448f01a6,
while doing that isn't enough to make my bigger repro case work
(if I port just that, something else asserts later on, but with
this fix here everything's fine in my bigger repro).
Differential Revision: https://reviews.llvm.org/D139199
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
If we have two files with the same weak symbol like so:
```
ltmp0:
_weak:
<contents>
```
and
```
ltmp1:
_weak:
<contents>
```
Linking them together should leave only one copy of `<contents>`, not
two. Previously, we would keep around both copies because of the
private-label `ltmp<N>` symbols (i.e. symbols that start with `l`) -- we
would not coalesce those, so we would treat them as retaining the
contents.
This matters for more than just size -- we are depending upon this
behavior internally for emitting a certain file format. This file
format's header is repeated in each object file, but we want it to
appear just once in our output.
Why can't we not emit those aliases to `_weak`, or reference the
`ltmp<N>` symbols instead of `_weak`? Well, MC actually adds `ltmp<N>`
symbols as part of the assembly-to-binary translation step. So any
codegen at the clang level can't access them.
All that said... this solution is actually kind of hacky. Here, we avoid
creating the private-label symbols at parse time. This is acceptable
since we never emit those symbols in our output. However, in ld64, any
aliasing temporary symbols (ignored or otherwise) won't retain coalesced
data. But implementing this is harder -- we would have to create those
symbols first (so we can emit their names later), but we would have to
ensure the linker correctly shuffles them around when their aliasees get
coalesced.
Additionally, ld64 treats these temporary symbols as functionally
equivalent to the weak symbols themselves -- that is, it will emit weak
binds when those non-weak temporary aliases are referenced. We have
imitated this behavior for private-label symbols, but implementing it for
local aliases in general seems substantially more difficult. I'm not
sure if any programs actually depend on this behavior though, so maybe
it's a moot point.
Finally, ld64 does all this regardless of whether
`.subsections_via_symbols` is specified. We don't. But again, given how
rare the lack of that directive is (I've only seen it from hand-written
assembly inputs), I don't think we need to worry about it.
Reviewed By: #lld-macho, oontvoo
Differential Revision: https://reviews.llvm.org/D139069
ld64 rejects `-no_pie` when targeting arm64, this mirrors that behavior.
Newer versions of ld64 also reject it based on minimum OS versions, but
that logic isn't in an open source dump yet so it isn't implemented
here.
Fixes https://github.com/llvm/llvm-project/issues/59115
Differential Revision: https://reviews.llvm.org/D138884
Breaks build of LLVMgold here:
```
/repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1108:19: error: no matching function for call to 'localCache'
Cache = check(localCache("ThinLTO", "Thin", options::cache_dir, AddBuffer));
^~~~~~~~~~
/repositories/llvm-project/llvm/include/llvm/Support/Caching.h:72:21: note: candidate function not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1102:20)' to 'llvm::AddBufferFn' (aka 'function<void (unsigned int, const llvm::Twine &, std::unique_ptr<MemoryBuffer>)>') for 4th argument
Expected<FileCache> localCache(
^
/repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1110:18: error: no viable conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'llvm::AddStreamFn' (aka 'function<Expected<std::unique_ptr<CachedFileStream>> (unsigned int, const llvm::Twine &)>')
check(Lto->run(AddStream, Cache));
^~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:375:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'std::nullptr_t' for 1st argument
function(nullptr_t) noexcept
^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:386:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'const std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream>> (unsigned int, const llvm::Twine &)> &' for 1st argument
function(const function& __x)
^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:404:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream>> (unsigned int, const llvm::Twine &)> &&' for 1st argument
function(function&& __x) noexcept
^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:435:2: note: candidate template ignored: requirement '_Callable<(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &, (lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20), std::__invoke_result<(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &, unsigned int, const llvm::Twine &>>::value' was not satisfied [with _Functor = (lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &]
function(_Functor&& __f)
^
/repositories/llvm-project/llvm/include/llvm/LTO/LTO.h:278:25: note: passing argument to parameter 'AddStream' here
Error run(AddStreamFn AddStream, FileCache Cache = nullptr);
^
```
This reverts commit 387620aa8c.
