Since we emit diagnostics for undefineds in Writer::scanRelocations()
and symbols referenced by -u flags aren't referenced by any relocations,
this needs some manual code (similar to the entry point).
Differential Revision: https://reviews.llvm.org/D94371
This is an initial base commit for ARM64 target arch support. I don't represent that it complete or bug-free, but wish to put it out for review now that some basic things like branch target & load/store address relocs are working.
I can add more tests to this base commit, or add them in follow-up commits.
It is not entirely clear whether I use the "ARM64" (Apple) or "AArch64" (non-Apple) naming convention. Guidance is appreciated.
Differential Revision: https://reviews.llvm.org/D88629
The LSDA pointers are encoded as offsets from the image base,
and arranged in one big contiguous array. Each second-level page records
the offset within that LSDA array which corresponds to the LSDA for its
first CU entry.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D95810
Note that there is a triple indirection involved with
personalities and compact unwind:
1. Two bits of each CU encoding are used as an offset into the
personality array.
2. Each entry of the personality array is an offset from the image base.
The resulting address (after adding the image base) should point within the
GOT.
3. The corresponding GOT entry contains the actual pointer to the
personality function.
To further complicate things, when the personality function is in the
object file (as opposed to a dylib), its references in
`__compact_unwind` may refer to it via a section + offset relocation
instead of a symbol relocation. Since our GOT implementation can only
create entries for symbols, we have to create a synthetic symbol at the
given section offset.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D95809
The Mach kernel & codesign on arm64 macOS has strict requirements for alignment and sequence of segments and sections. Dyld probably is just as picky, though kernel & codesign reject malformed Mach-O files before dyld ever has a chance.
I developed this diff by incrementally changing alignments & sequences to match the output of ld64. I stopped when my hello-world test program started working: `codesign --verify` succeded, and `execve(2)` didn't immediately fail with `errno == EBADMACHO` = `"Malformed Mach-O file"`.
Differential Revision: https://reviews.llvm.org/D94935
This extends {D92539} to work even when we are loading archive
members via `-force_load`. I uncovered this issue while trying to
force-load archives containing bitcode -- we were segfaulting.
In addition to fixing the `-force_load` case, this diff also addresses
the behavior of `-ObjC` when LTO bitcode is involved -- we need to
force-load those archive members if they contain ObjC categories.
Reviewed By: #lld-macho, smeenai
Differential Revision: https://reviews.llvm.org/D95265
This makes our error messages more informative. But the bigger motivation is for
LTO symbol resolution, which will be in an upcoming diff. The changes in this
one are largely mechanical.
Reviewed By: #lld-macho, smeenai
Differential Revision: https://reviews.llvm.org/D94316
Add per-reloc-type attribute bits and migrate code from per-target file into target independent code, driven by reloc attributes.
Many cleanups
Differential Revision: https://reviews.llvm.org/D95121
On z/OS, the following error message is not matched correctly in lit tests.
```
EDC5129I No such file or directory.
```
This patch uses a lit config substitution to check for platform specific error messages.
Reviewed By: muiez, jhenderson
Differential Revision: https://reviews.llvm.org/D95246
Just getting rid of some logspew as I test LLD under existing build
systems.
Reviewed By: #lld-macho, smeenai
Differential Revision: https://reviews.llvm.org/D95213
Run the ObjCARCContractPass during LTO. The legacy LTO backend (under
LTO/ThinLTOCodeGenerator.cpp) already does this; this diff just adds that
behavior to the new LTO backend. Without that pass, the objc.clang.arc.use
intrinsic will get passed to the instruction selector, which doesn't know how to
handle it.
In order to test both the new and old pass managers, I've also added support for
the `--[no-]lto-legacy-pass-manager` flags.
P.S. Not sure if the ordering of the pass within the pipeline matters...
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D94547
We were mishandling the case where both `__tbss` and `__thread_data` sections were
present.
TLVP relocations should be encoded as offsets from the start of `__thread_data`,
even if the symbol is actually located in `__thread_bss`. Previously, we were
writing the offset from the start of the containing section, which doesn't
really make sense since there's no way `tlv_get_addr()` can know which section a
given `tlv$init` symbol is in at runtime.
In addition, this patch ensures that we place `__thread_data` immediately before
`__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill
sections must also be at the end of their segments; we were already doing this,
but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always
possible to have it contiguous with `__thread_data`.
Fixes llvm.org/PR48657.
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D94329
D93491 implemented `--version` for the MachO LLD port, but asserts that the string contains something like "LLD N.N". However, this is just the cmake default for `LLD_VERSION_STRING`, and downstream users may choose a different value, e.g. a rolling distro may print "LLD trunk".
We didn't have support for parsing DriverKit in our `-platform`
flag, so add that too. Also remove a bunch of unnecessary namespace
prefixes.
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D93741
It's an extension to ld64, but all the other ports have it, and
someone asked for it in PR43721.
While here, change the COFF help text to match the other ports.
Differential Revision: https://reviews.llvm.org/D93491
Before this, a hello world program would contain many many unnecessary
entries in its string table.
No behavior change, just makes the string table in the output smaller
and more like ld64's.
Differential Revision: https://reviews.llvm.org/D93711
Private extern symbols are used for things scoped to the linkage unit.
They cause duplicate symbol errors (so they're in the symbol table,
unlike TU-scoped truly local symbols), but they don't make it into the
export trie. They are created e.g. by compiling with
-fvisibility=hidden.
If two weak symbols have differing privateness, the combined symbol is
non-private external. (Example: inline functions and some TUs that
include the header defining it were built with
-fvisibility-inlines-hidden and some weren't).
A weak private external symbol implicitly has its "weak" dropped and
behaves like a regular strong private external symbol: Weak is an export
trie concept, and private symbols are not in the export trie.
If a weak and a strong symbol have different privateness, the strong
symbol wins.
If two common symbols have differing privateness, the larger symbol
wins. If they have the same size, the privateness of the symbol seen
later during the link wins (!) -- this is a bit lame, but it matches
ld64 and this behavior takes 2 lines less to implement than the less
surprising "result is non-private external), so match ld64.
(Example: `int a` in two .c files, both built with -fcommon,
one built with -fvisibility=hidden and one without.)
This also makes `__dyld_private` a true TU-local symbol, matching ld64.
To make this work, make the `const char*` StringRefZ ctor to correctly
set `size` (without this, writing the string table crashed when calling
getName() on the __dyld_private symbol).
Mention in CommonSymbol's comment that common symbols are now disabled
by default in clang.
Mention in -keep_private_externs's HelpText that the flag only has an
effect with `-r` (which we don't implement yet -- so this patch here
doesn't regress any behavior around -r + -keep_private_externs)). ld64
doesn't explicitly document it, but the commit text of
http://reviews.llvm.org/rL216146 does, and ld64's
OutputFile::buildSymbolTable() checks `_options.outputKind() ==
Options::kObjectFile` before calling `_options.keepPrivateExterns()`
(the only reference to that function).
Fixes PR48536.
Differential Revision: https://reviews.llvm.org/D93609
* Migrate most of our tests to use `split-file` instead of `echo`
* Remove individual `rm -f %t/libfoo.a` commands in favor of a top-level `rm -rf %t`
* Remove unused `Inputs/libfunction.s`
Reviewed By: #lld-macho, compnerd
Differential Revision: https://reviews.llvm.org/D93604
Also remove iteration over ArchiveFile symbols in buildInputSectionPriorities --
that was rendered unnecessary after D92539, which included ObjFiles from
ArchiveFiles inside the `inputFiles` vector.
Reviewed By: #lld-macho, smeenai
Differential Revision: https://reviews.llvm.org/D93569
Obj-C symbols may have spaces and colons, which our previous order file
parser would be confused by. The order file format has made the very unfortunate
choice of using colons for its delimiters, which means that we have to use
heuristics to determine if a given colon is part of a symbol or not...
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D93567
The common encodings table holds only 127 entries. The encodings index for compact entries is 8 bits wide, and indexes 127..255 are stored locally to each second-level page. Prior to this diff, lld would `fatal()` if encodings overflowed the 127 limit.
This diff populates a per-second-level-page encodings table as needed. When the per-page encodings table hits its limit, we must terminate the page. If such early termination would consume fewer entries than a regular (non-compact) encoding page, then we prefer the regular format.
Caveat: one reason the common-encoding table might overflow is because of DWARF debug-info references, which are not yet implemented and will come with a later diff.
Differential Revision: https://reviews.llvm.org/D93267
TREATMENT can be `error`, `warning`, `suppress`, or `dynamic_lookup`
The `dymanic_lookup` remains unimplemented for now.
Differential Revision: https://reviews.llvm.org/D93263
Note that dylibs without *any* refs will still be loaded in the usual
(strong) fashion.
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D93435
Weak references need not necessarily be satisfied at runtime (but they must
still be satisfied at link time). So symbol resolution still works as per usual,
but we now pass around a flag -- ultimately emitting it in the bind table -- to
indicate if a given dylib symbol is a weak reference.
ld64's behavior for symbols that have both weak and strong references is
a bit bizarre. For non-function symbols, it will emit a weak import. For
function symbols (those referenced by BRANCH relocs), it will emit a
regular import. I'm not sure what value there is in that behavior, and
since emulating it will make our implementation more complex, I've
decided to treat regular weakrefs like function symbol ones for now.
Fixes PR48511.
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D93369
From what I can tell, it's essentially identical to
`-sub_library`, but it doesn't match files ending in ".dylib".
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D93276
Their addresses are already encoded as section-relative offsets, so
there's no need to rebase them at runtime. {D85080} has some context
on the weirdness of TLV sections.
Fixes llvm.org/PR48491.
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D93257
We were not setting forceWeakImport for file paths given by
`-weak_library` if we had already loaded the file. This diff fixes that
by having `loadDylib` return a cached DylibFile instance even if we have
already loaded that file.
We still avoid emitting multiple LC_LOAD_DYLIBs, but we achieve this by
making inputFiles a SetVector instead of relying on the `loadedDylibs`
cache.
Reviewed By: #lld-macho, smeenai
Differential Revision: https://reviews.llvm.org/D93255
lto-object-path.ll, like stabs.s, is disabled on Windows as the path
separators make it difficult to write a test that works across
platforms.
This diff also disables implicit-dylibs.s on Windows as we seem to emit
LC_LOAD_DYLIBs in a different order on that platform. This seems like a
bug in LLD that needs to be addressed (in a future diff).
Dylibs that are "public" -- i.e. top-level system libraries -- are considered
implicitly linked when another library re-exports them. That is, we should load
them & bind directly to their symbols instead of via their re-exporting
umbrella library. This diff implements that behavior by default, as well as an
opt-out flag.
In theory, this is just a performance optimization, but in practice it seems
that it's needed for correctness.
Fixes llvm.org/PR48395.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D93000
We need to initialize AsmParsers before any calls to `addFile`, as
bitcode files may require them. Otherwise we trigger `Assertion T &&
T->hasMCAsmParser()' failed`.
Reviewed By: #lld-macho, compnerd
Differential Revision: https://reviews.llvm.org/D92913
`-mcpu` and `-code-model` tests were copied from similar ones in
LLD-ELF.
There doesn't seem to be an equivalent test for `-mattr` in LLD-ELF, so
I've verified our behavior by cribbing a test from
CodeGen/X86/recip-fastmath.ll.
Reviewed By: #lld-macho, compnerd, MaskRay
Differential Revision: https://reviews.llvm.org/D92912
This was causing a crash as we were attempting to look up the
nonexistent parent OutputSection of the debug sections. We didn't detect
it earlier because there was no test for PIEs with debug info (PIEs
require us to emit rebases for X86_64_RELOC_UNSIGNED).
This diff filters out the debug sections while loading the ObjFiles. In
addition to fixing the above problem, it also lets us avoid doing
redundant work -- we no longer parse / apply relocations / attempt to
emit dyld opcodes for these sections that we don't emit.
Fixes llvm.org/PR48392.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D92904
This makes it possible for STABS entries to reference the debug info
contained in the LTO-compiled output.
I'm not sure how to test the file mtime within llvm-lit -- GNU and BSD
`stat` take different command-line arguments. I've omitted the check for
now.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D92537
Also error out if we find anything other than an object or bitcode file
in the archive.
Note that we were previously inserting the symbols and sections of the
unpacked ObjFile into the containing ArchiveFile. This was actually
unnecessary -- we can just insert the ObjectFile (or BitcodeFile) into
the `inputFiles` vector. This is the approach taken by LLD-ELF.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D92539
clang puts `-framework CoreFoundation` in this load command for files
that use @available / __builtin_available. Without support for this,
binaries that don't explicitly link to CoreFoundation fail to link.
Differential Revision: https://reviews.llvm.org/D92624
This helps us catch cases where we add support for a flag but forget to
remove HelpHidden from Options.td.
More explicit alternative to D92455
Differential Revision: https://reviews.llvm.org/D92575