Commit Graph

15358 Commits

Author SHA1 Message Date
Michael Eisel 44978a234b [lld/mac] Write output sections in parallel
This reduces linking time by ~8% for my project (1.19s -> 0.53s for
writeSections()). writeTo is const, which bodes well for it being
parallelizable, and I've looked through the different overridden versions and
can't see any race conditions. It produces the same byte-for-byte output for my
project.

Differential Revision: https://reviews.llvm.org/D126800
2022-06-08 20:11:50 -04:00
Florian Mayer f6b1bfb7d5 [ELF] Support 'G' in .eh_frame
Reviewed By: MaskRay, eugenis

Differential Revision: https://reviews.llvm.org/D127148
2022-06-08 14:28:58 -07:00
Florian Mayer 6fb4fe7285 Revert "[ELF] Support 'G' in .eh_frame"
This reverts commit 40f34fe4a8.
2022-06-08 13:52:38 -07:00
Florian Mayer 40f34fe4a8 [ELF] Support 'G' in .eh_frame
Reviewed By: MaskRay, eugenis

Differential Revision: https://reviews.llvm.org/D127148
2022-06-08 13:40:20 -07:00
Vy Nguyen 66bd14697b [lld-macho] Demangle symbol names in duplicate-symbol error when -demangle is specified
Differential Revision: https://reviews.llvm.org/D127110
2022-06-06 15:12:26 -04:00
Fangrui Song 025b309631 Revert D126950 "[lld][WebAssembly] Retain data segments referenced via __start/__stop"
This reverts commit dcf3368e33.

It breaks -DLLVM_ENABLE_ASSERTIONS=on builds. In addition, the description is
incorrect about ld.lld behavior. For wasm, there should be justification to add
the new mode.
2022-06-03 22:18:06 -07:00
Yuta Saito dcf3368e33 [lld][WebAssembly] Retain data segments referenced via __start/__stop
As well as ELF linker does, retain all data segments named X referenced
through `__start_X` or `__stop_X`.

For example, `FOO_MD` should not be stripped in the below case, but it's currently mis-stripped

```llvm
@FOO_MD  = global [4 x i8] c"bar\00", section "foo_md", align 1
@__start_foo_md = external constant i8*
@__stop_foo_md = external constant i8*
@llvm.used = appending global [1 x i8*] [i8* bitcast (i32 ()* @foo_md_size to i8*)], section "llvm.metadata"

define i32 @foo_md_size()  {
entry:
  ret i32 sub (
    i32 ptrtoint (i8** @__stop_foo_md to i32),
    i32 ptrtoint (i8** @__start_foo_md to i32)
  )
}
```

This fixes https://github.com/llvm/llvm-project/issues/55839

Reviewed By: sbc100

Differential Revision: https://reviews.llvm.org/D126950
2022-06-04 02:28:31 +00:00
Vy Nguyen 82de9bb66b [lld-macho] Addressed additional post-commit comments from D126046
- fixed newlines
- renamed helper function for clarity
- added additional comment

Differential Revision: https://reviews.llvm.org/D126792
2022-06-03 15:48:11 -04:00
Sam Clegg 87099a0438 [lld][WebAssembly] Remove unnecessary accessor methods. NFC
This is less code, and matches more closely the ELF linker.

Differential Revision: https://reviews.llvm.org/D126979
2022-06-03 11:43:44 -07:00
Fangrui Song e09f77d394 [ELF] Remove support for legacy .zdebug sections
.zdebug is unlikely used any longer: gcc -gz switched from legacy
.zdebug to SHF_COMPRESSED with binutils 2.26 (2016), which has been
several years. clang 14 dropped -gz=zlib-gnu support. According to
Debian Code Search (`gz=zlib-gnu`), no project uses -gz=zlib-gnu.

Remove .zdebug support to (a) simplify code and (b) allow removal of llvm-mc's
--compress-debug-sections=zlib-gnu.

In case the old object file `a.o` uses .zdebug, run `objcopy --decompress-debug-sections a.o`

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D126793
2022-06-02 13:37:19 -07:00
Matthias Braun 850d53a197 LTO: Decide upfront whether to use opaque/non-opaque pointer types
LTO code may end up mixing bitcode files from various sources varying in
their use of opaque pointer types. The current strategy to decide
between opaque / typed pointers upon the first bitcode file loaded does
not work here, since we could be loading a non-opaque bitcode file first
and would then be unable to load any files with opaque pointer types
later.

So for LTO this:
- Adds an `lto::Config::OpaquePointer` option and enforces an upfront
  decision between the two modes.
- Adds `-opaque-pointers`/`-no-opaque-pointers` options to the gold
  plugin; disabled by default.
- `--opaque-pointers`/`--no-opaque-pointers` options with
  `-plugin-opt=-opaque-pointers`/`-plugin-opt=-no-opaque-pointers`
  aliases to lld; disabled by default.
- Adds an `-lto-opaque-pointers` option to the `llvm-lto2` tool.
- Changes the clang driver to pass `-plugin-opt=-opaque-pointers` to
  the linker in LTO modes when clang was configured with opaque
  pointers enabled by default.

This fixes https://github.com/llvm/llvm-project/issues/55377

Differential Revision: https://reviews.llvm.org/D125847
2022-06-01 18:05:53 -07:00
Nico Weber 815825f442 [lld/mac] clang-format after f5709066e3 2022-06-01 14:53:08 -04:00
Michael Eisel f5709066e3 [lld/mac] Cache file IDs of symbols in emitStabs for faster sorting
This reduces the time emitStabs() takes by about 275ms, or 3% of overall
linking time for the project I'm on. Although the parent function is run in
parallel, it's one of the slowest tasks in that concurrent batch (I have
another optimization for another slow task as well).

Differential Revision: https://reviews.llvm.org/D126785
2022-06-01 14:51:34 -04:00
Fangrui Song 94573a49c9 [ELF][test] Change some tests to use SHF_COMPRESSED instead of legacy .zdebug 2022-06-01 00:18:54 -07:00
Sam Clegg 0e8f4ce31d [lld][WebAssembly] Fix crash on undefined+weak function syms in LTO objects
Symbols from LTO objects don't contain Wasm signatures, but we need a
signature when we create undefined/stub functions for missing weakly
undefined symbols.

Luckily, after LTO, we know that symbols that are not referenced by a
regular object file must not be needed in the final output so there
is no need to generate undefined/stub function for them.

Differential Revision: https://reviews.llvm.org/D126554
2022-05-27 11:41:34 -07:00
Derek Schuff a205f2904d [WebAssembly] Consolidate sectionTypeToString in BinaryFormat [NFC]
Currently there are 2 duplicate implementation, and I want to add
a use in a 3rd place. Combine them in lib/BinaryFormat so they can
be shared.

Also update toString for symbol and reloc types to use StringRef

Differential Revision: https://reviews.llvm.org/D126553
2022-05-27 09:26:36 -07:00
Andrew Ng a94d454390 [LLD][test] Update `zlib` tests for LLD commit c78c00dc16
Updates for these tests were missed because I didn't have zlib-dev
installed and thus the tests were unsupported and not run.
2022-05-27 12:08:24 +01:00
Andrew Ng c78c00dc16 [LLD][ELF] Drop the string null terminator from the hash in splitStrings
Differential Revision: https://reviews.llvm.org/D126484
2022-05-27 10:48:53 +01:00
Sam Clegg 98ff205fd8 [lld][WebAssembly] Update test after 87628f5804 2022-05-26 14:57:17 -07:00
Sam Clegg 87628f5804 [lld][WebAssembly] Require double dash for modern linker flags
This matches the behaviour of the ELF backend (in fact this change
is mostly just copying directly from ELF/Options.td).

Differential Revision: https://reviews.llvm.org/D126500
2022-05-26 14:42:52 -07:00
Sam Clegg 198815e18d [lld][WebAssembly] Avoid importing/exporting hidden symbols in shared libraries
We have some special handling for weakly defined symbols where we both
import and export them, but this is not needed for hidden symbols which
should never be imported or exported.

See https://github.com/emscripten-core/emscripten/pull/16972

This should also help with:
https://github.com/emscripten-core/emscripten/issues/15487

Differential Revision: https://reviews.llvm.org/D126491
2022-05-26 13:43:25 -07:00
Sam Clegg 966427b847 [lld][WebAssemlby] Check for command line flags with missing arguments
I'm really not sure how this was overlooked when we first ported lld
to Wasm.  The upstream code in the ELF backend has these two lines but
for some reason they never make it into the Wasm version.

Differential Revision: https://reviews.llvm.org/D126497
2022-05-26 13:35:27 -07:00
Vy Nguyen fae6bd7563 [lld-macho] Support -non_global_symbols_strip_list, -non_global_symbols_no_strip_list, -x
PR/55600

Differential Revision: https://reviews.llvm.org/D126046
2022-05-25 19:22:04 +07:00
Vy Nguyen c0ec1036d6 [lld-macho][nfc] Run clang-format on lld/MachO/*.{h,cpp}
- fixed inconsistent indents and spaces
- prevent extraneous formatting changes in other patches

Differential Revision: https://reviews.llvm.org/D126262
2022-05-24 08:36:20 +07:00
Sam Clegg 74f9841977 [lld][WebAssembly] Allow use of statically allocated TLS region.
It turns out we were already allocating static address space for TLS
data along with the non-TLS static data, but this space was going
unused/ignored.

With this change, we include the TLS segment in `__wasm_init_memory`
(which does the work of loading the passive segments into memory when a
module is first loaded).  We also set the `__tls_base` global to point
to the start of this segment.

This means that the runtime can use this static copy of the TLS data for
the first/primary thread if it chooses, rather than doing a runtime
allocation prior to calling `__wasm_init_tls`.

Practically speaking, this will allow emscripten to avoid dynamic
allocation of TLS region on the main thread.

Differential Revision: https://reviews.llvm.org/D126107
2022-05-23 17:27:17 -07:00
Sam Clegg 4f6ac96926 [lld][WebAssemlby] Add TLS test to lld/test/wasm/data-segments.ll. NFC
Differential Revision: https://reviews.llvm.org/D126104
2022-05-20 17:44:05 -07:00
Alex Brachet 190b0f42cf [lld-macho] Stop crash when emitting personalities with -dead_strip
The <internal> symbol was tripping an assertion in getVA() because it
was not marked as used. Per the comment above that symbols creation,
dead stripping has already occurred so marking this symbol as used is
accurate.

Fixes https://github.com/llvm/llvm-project/issues/55565

Differential revision: https://reviews.llvm.org/D126072
2022-05-20 21:40:47 +00:00
Keith Smiley 505ddb6b74
[lld][test] Delete empty Unit test directory
This became empty when we removed the legacy macho lld. This results in
a warning when running `check-lld`. We can revert this in the future if
we want unit tests.

Differential Revision: https://reviews.llvm.org/D125436
2022-05-19 12:06:42 -07:00
Ben Shi 8527f32f0a [lld][ELF] Support BFD name elf32-avr
Reviewed By: MaskRay

differential Revision: https://reviews.llvm.org/D125544
2022-05-18 00:00:14 +00:00
Vy Nguyen 3cde6d83f8 [nfc][lld-macho] Follow up fixes to bd9e46815d
Need -DAG in the first expect statement too
2022-05-16 20:53:53 -04:00
Vy Nguyen bd9e46815d [nfc][lld-macho] Fixed test from https://reviews.llvm.org/D125732
Details:
The test was incorrectly expecting the error messages for the export symbols to have a particular order.
It shouldn't because the export symbol list is processed concurrently.
2022-05-16 20:46:15 -04:00
Vy Nguyen a997cdc3b7 [lld-macho] Temporarily disable test on windows
The metadata seems to be demangled differently
2022-05-16 20:39:52 -04:00
Vy Nguyen 4c5b187f2c [lld-macho] Demangle symbol names in export-symbol error messages when -demangle is specified.
PR/55512

Reviewed By: keith

Differential Revision: https://reviews.llvm.org/D125732
2022-05-16 19:48:03 -04:00
Nico Weber c554aeeea7 fix typos to cycle bots 2022-05-14 21:19:19 -04:00
Fangrui Song 912f5f7183 [ELF][test] Add an input section description test with "()" in the filename 2022-05-13 12:02:14 -07:00
Fangrui Song 82482e709f [ELF][test] Clean up linkerscript/{filename-spec.s,group.s} 2022-05-13 11:53:03 -07:00
Fangrui Song 177fd72f5f [ELF] Disallow input section description without a filename
GNU ld does not allow `.foo : { (*foo) }`, but we may recognize it as three
input section descriptions: file "(" with any section name, file "*foo" with
any section name, file ")" with any section name. Disallow the error-prone usage.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D125523
2022-05-13 11:06:01 -07:00
Nico Weber 0f9a138034 fix typos to cycle bots 2022-05-13 08:57:08 -04:00
Fangrui Song 2ac8ce5d56 Revert D125410 "[ELF] Align the end of PT_GNU_RELRO to max-page-size instead of common-page-size"
This reverts commit ebdb9d635a.

Changing p_memsz is insufficient and may make PT_GNU_RELRO extend beyond the
PT_LOAD.
2022-05-12 20:41:22 -07:00
Fangrui Song ebdb9d635a [ELF] Align the end of PT_GNU_RELRO to max-page-size instead of common-page-size
We picked common-page-size to match GNU ld. Recently, the resolution to GNU ld
https://sourceware.org/bugzilla/show_bug.cgi?id=28824 (milestone: 2.39) switched
to max-page-size so that the last page can be protected by RELRO in case the
system page size is larger than common-page-size.

Thanks to our two RW PT_LOAD scheme (D58892), switching to max-page-size does
not change file size (while GNU ld's scheme may increase file size).

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D125410
2022-05-12 11:03:12 -07:00
Tapan Thaker d64bad8ff1
[lld/macho] Fixes the -ObjC flag
When checking the segment name for Swift symbols, we should be checking that they start with `__swift` instead of checking for equality

Fixes the issue https://github.com/llvm/llvm-project/issues/55355

Reviewed By: #lld-macho, keith, thevinster

Differential Revision: https://reviews.llvm.org/D125250
2022-05-11 17:00:39 -07:00
Greg McGary ebc2529206 [ELF] Move InputSectionBase::rawData member [NFC] 2022-05-09 21:20:14 -07:00
Douglas Yung 62f7dc7c03 Add x86 to REQUIRES line in test as suggested in https://reviews.llvm.org/D124105. 2022-05-09 18:01:50 -07:00
Alex Richardson 7c20e7ca86 [ELF] Support -plugin-opt=stats-file=
This flag is added by clang::driver::tools::addLTOOptions() and was causing
errors for me when building the llvm-test-suite repository with LTO and
-DTEST_SUITE_COLLECT_STATS=ON. This replaces the --stats-file= option
added in 1c04b52b25 since the flag is only
used for LTO and should therefore be in the -plugin-opt= namespace.

Additionally, this commit fixes the `REQUIRES: asserts` that was added in
948d05324a150a5a24e93bad07c9090d5b8bd129: the feature was never defined in
the lld test suite so it effectively disabled the test.

Reviewed By: MaskRay, MTC

Differential Revision: https://reviews.llvm.org/D124105
2022-05-09 15:04:40 +00:00
Xiaodong Liu 36d4f42c36 [lld] Fix typo for processAux; NFC
Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D125163
2022-05-09 10:21:47 +08:00
Fangrui Song b3d5bb3b30 [ELF] Change (NOLOAD) type mismatch to use SHT_NOBITS instead of SHT_PROGBITS
Placing a non-SHT_NOBITS input section in an output section specified with
(NOLOAD) is fishy but used by some projects. D118840 changed the output type to
SHT_PROGBITS, but using the specified type seems to make more sense and improve
GNU ld compatibility: `(NOLOAD)` seems to change the output section type
regardless of input.

I think we should keep the current type mismatch warning as it does indicate an
error-prone usage.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D125074
2022-05-06 07:49:42 -07:00
Nico Weber 895a72111b [lld/mac] Support writing zippered dylibs and bundles
With -platform_version flags for two distinct platforms,
this writes a LC_BUILD_VERSION header for each.

The motivation is that this is needed for self-hosting with lld as linker
after D124059.

To create a zippered output at the clang driver level, pass

    -target arm64-apple-macos -darwin-target-variant arm64-apple-ios-macabi

to create a zippered dylib.

(In Xcode's clang, `-darwin-target-variant` is spelled just `-target-variant`.)

(If you pass `-target arm64-apple-ios-macabi -target-variant arm64-apple-macos`
instead, ld64 crashes!)

This results in two -platform_version flags being passed to the linker.

ld64 also verifies that the iOS SDK version is at least 13.1. We don't do that
yet. But ld64 also does that for other platforms and we don't. So we need to
do that at some point, but not in this patch.

Only dylib and bundle outputs can be zippered.

I verified that a Catalyst app linked against a dylib created with

    clang -shared foo.cc -o libfoo.dylib \
          -target arm64-apple-macos \
          -target-variant arm64-apple-ios-macabi \
          -Wl,-install_name,@rpath/libfoo.dylib \
          -fuse-ld=$PWD/out/gn/bin/ld64.lld

runs successfully. (The app calls a function `f()` in libfoo.dylib
that returns a const char* "foo", and NSLog(@"%s")s it.)

ld64 is a bit more permissive when writing zippered outputs,
see references to "unzippered twins". That's not implemented yet.
(If anybody wants to implement that, D124275 is a good start.)

Differential Revision: https://reviews.llvm.org/D124887
2022-05-04 19:23:35 -04:00
Jez Ng 19bb38b9c9 [lld-macho][nfc] Set test min version to 11.0
The arm64-apple-macos triple is only valid for versions >= 11.0. (If
one passes arm64-apple-macos10.15 to llvm-mc, the output's min version is still
11.0). In order to write tests easily for both target archs, let's up the
default min version in our tests.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D124562
2022-05-04 18:01:34 -04:00
Fangrui Song 5a44980f0a [ELF] Support custom sections between DATA_SEGMENT_ALIGN and DATA_SEGMENT_RELRO_END
We currently hard code RELRO sections. When a custom section is between
DATA_SEGMENT_ALIGN and DATA_SEGMENT_RELRO_END, we may report a spurious
`error: section: ... is not contiguous with other relro sections`. GNU ld
makes such sections RELRO.

glibc recently switched to default --with-default-link=no. This configuration
places `__libc_atexit` and others between DATA_SEGMENT_ALIGN and
DATA_SEGMENT_RELRO_END. This patch allows such a ld.bfd --verbose
linker script to be fed into lld.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D124656
2022-05-04 01:10:46 -07:00
Douglas Yung 0cb59607dc Mark test icf-safe.s as requiring aarch64 to fix buildbots which don't build that target. 2022-05-03 22:45:43 -07:00
Alex Borcan e29dc0c6fd [lld] Implement safe icf for MachO
This change implements --icf=safe for MachO based on addrsig section that is implemented in D123751.

Reviewed By: int3, #lld-macho

Differential Revision: https://reviews.llvm.org/D123752
2022-05-03 21:01:03 -04:00
Fangrui Song 3bc79808d0 [ELF] Fix branch range computation when picking ThunkSection
Similar to D117734. Take AArch64 as an example when the branch range is +-0x8000000.

getISDThunkSec returns `ts` when `src-0x8000000-r_addend <= tsBase < src-0x8000000`
and the new thunk will be placed in `ts` (`ts->addThunk(t)`). However, the new
thunk (at the end of ts) may be unreachable from src. In the next pass,
`normalizeExistingThunk` reverts the relocation back to the original target.
Then a new thunk is created and the same `ts` is picked as before. The `ts` is
still unreachable.

I have observed it in one test with a sufficiently large r_addend (47664): there
are initially 245 Thunk's, then in each pass 14 new Thunk's are created and get
appended to the unreachable ThunkSection. After 15 passes lld fails with
`thunk creation not converged`.

The new test aarch64-thunk-reuse2.s checks the case.

Without `- pcBias`, arm-thumb-thunk-empty-pass.s and arm-thunk-multipass-plt.s
will fail.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D124653
2022-05-03 08:46:15 -07:00
Fangrui Song 4007756499 [ELF][test] Improve data-segment-relro.test 2022-04-28 22:29:39 -07:00
Shoaib Meenai 7cc328600e [ELF] Prevent LTO stripping of wrapped script-referenced symbols
After 1af25a9860, we stop unconditionally
retaining wrapped symbols, which means that LTO's summary-based global
dead stripping can eliminate them even if they'll be referenced by a
linker script after the wrapping is performed. Mark symbols referenced
in linker scripts as `referenced` in addition to `isUsedInRegularObj`,
so that the wrapping logic correctly sets `referencedAfterWrap` for the
symbols which will be referenced after wrapping, which will prevent LTO
from eliminating them.

An alternative would have been to change the `referencedAfterWrap` logic
to look at `isUsedInRegularObj` in addition to `referenced`, but
`isUsedInRegularObj` is also set in other places (e.g. for the entry
symbol), and it's not clear that we want `referencedAfterWrap` to take
all those places into account, so it seemed better to keep that logic
as-is and instead set `referenced` for linker script-referenced symbols.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D124433
2022-04-26 18:48:26 -07:00
Nico Weber 010acc52a8 [lld/mac] Revert libcompiler_rt.dylib version check change
This reverts D117925 since it's no longer needed after D124336.

Differential Revision: https://reviews.llvm.org/D124354
2022-04-25 06:55:49 -04:00
Nico Weber 3254f46884 [lld/mac] For catalyst outputs, tolerate implicitly linking against mac-only tbd files
Before this,

  clang empty.cc -target x86_64-apple-ios13.1-macabi \
      -framework CoreServices -fuse-ld=lld

would error out with

    ld64.lld: error: path/to/MacOSX.sdk/System/Library/Frameworks/
         CoreServices.framework/Versions/A/Frameworks/CarbonCore.framework/
         Versions/A/CarbonCore.tbd(
             /System/Library/Frameworks/
             CoreServices.framework/Versions/A/Frameworks/CarbonCore.framework/
             Versions/A/CarbonCore) is incompatible with x86_64 (macCatalyst)

Now it works, like with ld64.

Differential Revision: https://reviews.llvm.org/D124336
2022-04-23 21:43:46 -04:00
Jez Ng 013efeec34 [lld-macho] Remove stray debug printf
Accidentally committed as part of b440c25742.
2022-04-22 22:17:24 -04:00
Vincent Lee 9f2272ff51 [lld-macho] Allow dead_strip to work with exported private extern symbols
It seems like we are overly asserting when running `-dead_strip` with
exported symbols. ld64 treats exported private extern symbols as a liveness
root. Loosen the assert to match ld64's behavior.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D124143
2022-04-22 18:45:27 -07:00
Shoaib Meenai 2a04f5c455 [ELF] Drop unused original symbol after wrapping if not defined
We were previously only omitting the original of a wrapped symbol if it
was not used by an object file and undefined. We can tighten the second
condition to drop any symbol that isn't defined instead, which lets us
drop a previous check (added in https://reviews.llvm.org/D118756) that
was only covering some such symbols.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D124065
2022-04-22 16:47:15 -07:00
Shoaib Meenai 1af25a9860 [ELF] Fix wrapping symbols produced during LTO codegen
We were previously not correctly wrapping symbols that were only
produced during LTO codegen and unreferenced before then, or symbols
only referenced from such symbols. The root cause was that we weren't
marking the wrapped symbol as used if we only saw the use after LTO
codegen, leading to the failed wrapping.

Fix this by explicitly tracking whether a symbol will become referenced
after wrapping is done. We can use this property to tell LTO to preserve
such symbols, instead of overload isUsedInRegularObj for this purpose.
Since we're no longer setting isUsedInRegularObj for all symbols which
will be wrapped, its value at the time of performing the wrapping in the
symbol table will accurately reflect whether the symbol was actually
used in an object (including in an LTO-generated object), and we can
propagate that value to the wrapped symbol and thereby ensure we wrap
correctly.

This incorrect wrapping was the only scenario I was aware of where we
produced an invalid PLT relocation, which D123985 started diagnosing,
and with it fixed, we lose the test for that diagnosis. I think it's
worth keeping the diagnosis though, in case we run into other issues in
the future which would be caught by it.

Fixes PR50675.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D124056
2022-04-22 16:45:21 -07:00
Shoaib Meenai b862bcbf44 [ELF] Move SymbolUnion assertions to source file
Otherwise they fires for every single file which includes the header,
which is very noisy when building.

Reviewed By: MaskRay, peter.smith

Differential Revision: https://reviews.llvm.org/D124041
2022-04-22 16:41:14 -07:00
Jez Ng c242e10c74 [lld-macho] Fix ICF crash when comparing symbol relocs
Previously, when encountering a symbol reloc located in a literal section, we
would look up the contents of the literal at the `symbol value + addend` offset
within the literal section. However, it seems that this offset is not guaranteed
to be valid. Instead, we should use just the symbol value to retrieve the
literal's contents, and compare the addend values separately. ld64 seems to do
this.

Reviewed By: #lld-macho, thevinster

Differential Revision: https://reviews.llvm.org/D124223
2022-04-22 15:36:53 -04:00
Jez Ng e6382d23fc [lld-macho][nfc] Simplify unwind section lookup
Previously, we stored a pointer from the ObjFile to its compact unwind
section in order to avoid iterating over the file's sections a second
time. However, given the small number of sections (not subsections) per
file, this caching was really quite unnecessary. We will soon do lookups
for more sections (such as the `__eh_frame` section), so let's simplify
the code first.

Reviewed By: #lld-macho, Roger

Differential Revision: https://reviews.llvm.org/D123434
2022-04-22 15:36:53 -04:00
Keith Smiley 2d8cf26d08 [lld-macho] Fix crash on invalid framework tbd
Previously these would crash because `file` is null in the case there is
an invalid tbd file.

Differential Revision: https://reviews.llvm.org/D124271
2022-04-22 10:26:48 -07:00
Nico Weber 9c00e3d49e [lld/win] Mention in release notes that /winsysroot: currently requires /machine:
Differential Revision: https://reviews.llvm.org/D124254
2022-04-22 09:40:39 -04:00
Nico Weber 889847922d [lld/mac] Warn that writing zippered outputs isn't implemented
A "zippered" dylib contains several LC_BUILD_VERSION load commands, usually
one each for "normal" macOS and one for macCatalyst.

These are usually created by passing something like

   -shared -target arm64-apple-macos -darwin-target-variant arm64-apple-ios13.1-macabi

to clang, which turns it into

    -platform_version macos 12.0.0 12.3 -platform_version "mac catalyst" 14.0.0 15.4

for the linker.

ld64.lld can read these files fine, but it can't write them.  Before this
change, it would just silently use the last -platform_version flag and ignore
the rest.

This change adds a warning that writing zippered dylibs isn't implemented yet
instead.

Sadly, parts of ld64.lld's test suite relied on the previous
"silently use last flag" semantics for its test suite: `%lld` always expanded
to `ld64.lld -platform_version macos 10.15 11.0` and tests that wanted a
different value passed a 2nd `-platform_version` flag later on. But this now
produces a warning if the platform passed to `-platform_version` is not `macos`.

There weren't very many cases of this, so move these to use `%no-arg-lld` and
manually pass `-arch`.

Differential Revision: https://reviews.llvm.org/D124106
2022-04-21 12:05:56 -04:00
Fangrui Song f4a3569d0a [ELF] Fix spurious GOT/PLT assertion failure when .dynsym is discarded
Linux kernel arch/arm64/kernel/vmlinux.lds.S discards .dynsym . D123985 triggers
a spurious assertion failure. Detect the case with
`!mainPart->dynSymTab->getParent()`.
2022-04-20 22:49:49 -07:00
Shoaib Meenai 4641d86e45 [ELF] Shrink binding and type in Symbol
STB_HIPROC and STT_HIPROC are both 15, so we can fit the symbol binding
and type in 4 bits. This gives us an additional byte to use for Symbol
flags (without increasing the type's size), which I'll be making use of
in the next diff.

Reorder type and binding based on a suggestion from @MaskRay, to
optimize st_info computation on little-endian systems (see
https://godbolt.org/z/nMn8Yar43).

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D124042
2022-04-20 10:46:36 -07:00
Shoaib Meenai 610a0e8b53 [ELF] Assert on invalid GOT or PLT relocations
Because of https://llvm.org/PR50675, we can end up producing a PLT
relocation referencing a symbol that's dropped from the dynamic symbol
table, which in turn causes a crash at runtime. We ran into this again
recently, resulting in crashes for our users. A subsequent diff will fix
that issue, but add an assert to catch it if it happens again.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D123985
2022-04-20 10:46:04 -07:00
Eli Friedman 13fc178173 Force GHashCell to be 8-byte-aligned.
Otherwise, with recent versions of libstdc++, clang can't tell that the
atomic operations are properly aligned, and generates calls to
libatomic.  (Actually, because of the use of reinterpret_cast, it wasn't
guaranteed to be aligned, but I think it ended up being aligned in
practice.)

Fixes https://github.com/llvm/llvm-project/issues/54790 , the part where
LLVM failed to build.

Differential Revision: https://reviews.llvm.org/D123872
2022-04-18 08:46:03 -07:00
Pavel Kosov a5b7ea0783 [llvm-objdump] Implemented PrintBranchImmAsAddress for MIPS
Updated MipsInstPrinter to print absolute hex offsets for branch instructions.
It is necessary to make the llvm-objdump output close to the gnu objdump output.
This implementation is based on the implementation for RISC-V.

OS Laboratory. Huawei Russian Research Institute. Saint-Petersburg

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D123764
2022-04-15 23:48:38 +02:00
Fangrui Song b483ce1228 [ELF][ARM] Fix unneeded thunk for branches to hidden undefined weak
Similar to D123750 for AArch64.
2022-04-14 23:58:13 -07:00
Fangrui Song 02eab52866 [ELF][AArch64] Fix unneeded thunk for branches to hidden undefined weak
Similar to D119787 for PPC64.

A hidden undefined weak may change its binding to local before some
`isUndefinedWeak` code, so some `isUndefinedWeak` code needs to be changed to
`isUndefined`. The undefined non-weak case has been errored, so just using
`isUndefined` is fine.

The Linux kernel recently has a usage that a branch from 0xffff800008491ee0
references a hidden undefined weak symbol `vfio_group_set_kvm`.
It relies on the behavior that a branch to undefined weak resolving to the next
instruction, otherwise it'd see spurious relocation out of range errors.

Fixes https://github.com/ClangBuiltLinux/linux/issues/1624

Differential Revision: https://reviews.llvm.org/D123750
2022-04-14 11:32:30 -07:00
Jez Ng 2a6669060f [lld-macho][nfc] De-templatize UnwindInfoSection
Follow-on to {D123276}. Now that we work with an internal
representation of compact unwind entries, we no longer need to template
our UnwindInfoSectionImpl code based on the pointer size of the target
architecture.

I've still kept the split between `UnwindInfoSectionImpl` and
`UnwindInfoSection`. I'd introduced that split in order to do type
erasure, but I think it's still useful to have in order to keep
`UnwindInfoSection`'s definition in the header file clean.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D123277
2022-04-13 16:19:22 -04:00
Tobias Hieta 837d16fb4c [NFC] Simplify /noimplib argument logic 2022-04-13 16:40:30 +02:00
Tobias Hieta 2af4385477 [LLD][COFF] Add support for /noimplib
Mostly for compatibility reasons with link.exe this flag
makes sure we don't write a implib - not even when /implib
is also passed, that's how link.exe works.

Differential Revision: https://reviews.llvm.org/D123591
2022-04-13 16:40:29 +02:00
Tobias Hieta eb4eef9ec4 [LLD][COFF] Add support for /noimplib
Mostly for compatibility reasons with link.exe this flag
makes sure we don't write a implib - not even when /implib
is also passed, that's how link.exe works.

Reviewed By: mstorsjo

Differential Revision: https://reviews.llvm.org/D123591
2022-04-13 10:32:44 +02:00
Jez Ng 1cff723ff5 [lld-macho][nfc] Use includeInSymtab for all symtab-skipping logic
{D123302} got me looking deeper at `includeInSymtab`. I thought it was a
little odd that there were excluded (live) symbols for which
`includeInSymtab` was false; we shouldn't have so many different ways to
exclude a symbol. As such, this diff makes the `L`-prefixed-symbol
exclusion code use `includeInSymtab` too. (Note that as part of our
support for `__eh_frame`, we will also be excluding all `__eh_frame`
symbols from the symtab in a future diff.)

Another thing I noticed is that the `emitStabs` code never has to deal
with excluded symbols because `SymtabSection::finalize()` already
filters them out. As such, I've updated the comments and asserts from
{D123302} to reflect this.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D123433
2022-04-11 15:45:46 -04:00
Nico Weber 75196b99fb [llvm-lib] Add /WX, warn by default on empty inputs, add opt-out
lib.exe by default exits successfully without writing an output
file when no inputs are passed. llvm-lib has the same behavior,
for compatibility.

This behavior interacts poorly with build systems: If a static
library target had no inputs, llvm-lib would not produce an output
file, causing ninja (or make, or a similar system) to successfully
run that step, but then re-run it on the next build.

After this patch, llvm-lib emits a warning in this case, that with
/WX can be turned into an error. That way, ninja (or make, or...)
will mark the initial build as failed.

People who don't like the warning can use /ignore:emptyoutput to
suppress it.

The warning also points out the existing flag /llvmlibempty which
forces creation of an empty .lib file (this is an extension to lib.exe).

Differential Revision: https://reviews.llvm.org/D123517
2022-04-11 13:15:30 -04:00
Vy Nguyen 1477964413 [lld][macho]Fix test to sort symbol table before dumping
Details: The test previously expected a specific order of those symbols, which is not guaranteed (could change simply due to hashing changes, etc).
So we change it to explicitly sort the symbols before checking contents.

PR/53026

Differential Revision: https://reviews.llvm.org/D116813
2022-04-11 12:01:04 -04:00
Jez Ng 82dcf30636 [lld-macho] Use fewer indirections in UnwindInfo implementation
The previous implementation of UnwindInfoSection materialized
all the compact unwind entries & applied their relocations, then parsed
the resulting data to generate the final unwind info. This design had
some unfortunate conseqeuences: since relocations can only be applied
after their referents have had addresses assigned, operations that need
to happen before address assignment must contort themselves. (See
{D113582} and observe how this diff greatly simplifies it.)

Moreover, it made synthesizing new compact unwind entries awkward.
Handling PR50956 will require us to do this synthesis, and is the main
motivation behind this diff.

Previously, instead of generating a new CompactUnwindEntry directly, we
would have had to generate a ConcatInputSection with a number of
`Reloc`s that would then get "flattened" into a CompactUnwindEntry.

This diff introduces an internal representation of `CompactUnwindEntry`
(the former `CompactUnwindEntry` has been renamed to
`CompactUnwindLayout`). The new CompactUnwindEntry stores references to
its personality symbol and LSDA section directly, without the use of
`Reloc` structs.

In addition to being easier to work with, this diff also allows us to
handle unwind info whose personality symbols are located in sections
placed after the `__unwind_info`.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D123276
2022-04-08 23:49:07 -04:00
Matt Arsenault 63fe6d7eae lld/AMDGPU: Fix asserts if no object files are involved in link
Fixes issue 47690. The reproduction steps produced a shared object
from clang directly, and then fed the shared object back into
lld. With no regular object files, this assert was hit. I'm not sure
if we need to or should be looking for equivalent fields in shared
objects.
2022-04-08 14:18:52 -04:00
Jorge Gorbe Moya 627f55b3ae Fix format specifier. NFCI.
Using a portable format specifier avoids a "format specifies type
'unsigned long long' but the argument has type 'uint64_t' (aka 'unsigned
long') [-Werror,-Wformat]" error depending on the exact definition of
`uint64_t`.
2022-04-07 15:26:49 -07:00
Zequan Wu 1da67ecefd [llvm-symbolizer] Fix line offset for inline site.
This fixes the issue when the current line offset is actually for next range.

Maintain a current code range with current line offset and cache next file/line
offset. Update file/line offset after finishing current range.

Differential Revision: https://reviews.llvm.org/D123151
2022-04-07 15:17:59 -07:00
Jez Ng b440c25742 [lld-macho][nfc] Give non-text ConcatOutputSections order-independent finalization
This diff is motivated by my work to add proper DWARF unwind support. As
detailed in PR50956 functions that need DWARF unwind need to have
compact unwind entries synthesized for them. These CU entries encode an
offset within `__eh_frame` that points to the corresponding DWARF FDE.

In order to encode this offset during
`UnwindInfoSectionImpl::finalize()`, we need to first assign values to
`InputSection::outSecOff` for each `__eh_frame` subsection. But
`__eh_frame` is ordered after `__unwind_info` (according to ld64 at
least), which puts us in a bit of a bind: `outSecOff` gets assigned
during finalization, but `__eh_frame` is being finalized after
`__unwind_info`.

But it occurred to me that there's no real need for most
ConcatOutputSections to be finalized sequentially. It's only necessary
for text-containing ConcatOutputSections that may contain branch relocs
which may need thunks. ConcatOutputSections containing other types of
data can be finalized in any order.

This diff moves the finalization logic for non-text sections into a
separate `finalizeContents()` method. This method is called before
section address assignment & unwind info finalization takes place. In
theory we could call these `finalizeContents()` methods in parallel, but
in practice it seems to be faster to do it all on the main thread.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D123279
2022-04-07 18:13:27 -04:00
Fangrui Song be01af4a0f [ELF] Fix non-relocatable-non-emit-relocs --gc-sections to discard .L symbols
This reverts commit 764cd491b1, which I
incorrectly assumed NFC partly because there were no test coverage for the
non-relocatable non-emit-relocs case before 9d6d936243fe343abe89323a27c7241b395af541.

The interaction of {,-r,--emit-relocs} {,--discard-locals} {,--gc-sections} is
complex but without -r/--emit-relocs, --gc-sections does need to discard .L
symbols like --no-gc-sections. The behavior matches GNU ld.
2022-04-07 14:34:32 -07:00
Fangrui Song e25c41803f [ELF][test] Improve discard-locals.s 2022-04-07 14:24:15 -07:00
Nico Weber 2cb3d28b17 [lld/mac] Add some comments and asserts
I was wondering if SymtabSection::emitStabs() should check
defined->includeInSymtab. Add asserts and comments explaining why that's not
necessary.

No behavior change.

Differential Revision: https://reviews.llvm.org/D123302
2022-04-07 15:43:28 -04:00
Jez Ng f004ecf6ec [lld-macho][nfc] Remove indirection when looking up common section members
{D118797} means that we can now check the name/segname of a given
section directly, instead of having to look those properties up on one
of its subsections. This allows us to simplify our code.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D123275
2022-04-07 14:28:52 -04:00
Jez Ng da6b6b3c82 [lld-macho][nfc] Factor out findSymbolAtOffset
Our compact unwind handling code currently has some logic to locate a
symbol at a given offset in an InputSection. The EH frame code will need
to do something similar, so let's factor out the code.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D123301
2022-04-07 09:13:39 -04:00
Nico Weber 8c1ea1ab81 [lld/mac] Don't emit stabs entries for functions folded during ICF
This matches ld64, and makes dsymutil work better with lld's output.
Fixes PR54783, see there for details.

Reduces time needed to run dsymutil on Chromium Framework from 8m30s
(which is already down from 26 min with D123218) to 6m30s and removes
many lines of "could not find object file symbol for symbol" from dsymutil output
(previously: several MB of those messages, now dsymutil is completely silent).

Differential Revision: https://reviews.llvm.org/D123252
2022-04-07 08:09:32 -04:00
Simon Pilgrim 156b94c2d3 Fix "result of 32-bit shift implicitly converted to 64 bits" MSVC warning. NFC. 2022-04-07 11:25:09 +01:00
Nikita Popov b8f50abd04 [lld] Remove support for legacy pass manager
This removes options for performing LTO with the legacy pass
manager in LLD. Options that explicitly enable the new pass manager
are retained as no-ops.

Differential Revision: https://reviews.llvm.org/D123219
2022-04-07 10:17:31 +02:00
Tobias Hieta 0dfa8a019d [LLD][COFF] Fix TypeServerSource matcher with more than one collision
Follow-up from 98bc304e9f - while that
commit fixed when you had two PDBs colliding on the same Guid it didn't
fix the case where you had more than two PDBs using the same Guid.

This commit fixes that and also tests much more carefully that all
the types are correct no matter the order.

Reviewed By: aganea, saudi

Differential Revision: https://reviews.llvm.org/D123185
2022-04-07 09:33:46 +02:00
Fangrui Song c29c19cb53 [ELF] Ignore --no-add-needed
It is used by a few projects like keepassxc and mumble.
Also see https://bugzilla.redhat.com/show_bug.cgi?id=2070813 that Fedora gcc has
an (unneeded) gcc12-no-add-needed.patch which adds --no-add-needed, although
--[no-]add-needed has been deprecated in GNU ld since 2009. Adding this has low
costs and makes several folks happy.

This basically restores 8f13bef575.

Fixes https://github.com/llvm/llvm-project/issues/54756
2022-04-06 22:41:27 -07:00
Jez Ng e4b286211c [lld-macho][nfc] Rearrange order of statements to clarify data dependencies 2022-04-07 00:00:41 -04:00
Nikita Popov ed4e6e0398 [cmake] Remove LLVM_ENABLE_NEW_PASS_MANAGER cmake option
Or rather, error out if it is set to something other than ON. This
removes the ability to enable the legacy pass manager by default,
but does not remove the ability to explicitly enable it through
various flags like -flegacy-pass-manager or -enable-new-pm=0.

I checked, and our test suite definitely doesn't pass with
LLVM_ENABLE_NEW_PASS_MANAGER=OFF anymore.

Differential Revision: https://reviews.llvm.org/D123126
2022-04-06 09:52:21 +02:00
Martin Storsjö 46776f7556 Fix warnings about variables that are set but only used in debug mode
Add void casts to mark the variables used, next to the places where
they are used in assert or `LLVM_DEBUG()` expressions.

Differential Revision: https://reviews.llvm.org/D123117
2022-04-06 10:01:46 +03:00
Argyrios Kyrtzidis 330268ba34 [Support/Hash functions] Change the `final()` and `result()` of the hashing functions to return an array of bytes
Returning `std::array<uint8_t, N>` is better ergonomics for the hashing functions usage, instead of a `StringRef`:

* When returning `StringRef`, client code is "jumping through hoops" to do string manipulations instead of dealing with fixed array of bytes directly, which is more natural
* Returning `std::array<uint8_t, N>` avoids the need for the hasher classes to keep a field just for the purpose of wrapping it and returning it as a `StringRef`

As part of this patch also:

* Introduce `TruncatedBLAKE3` which is useful for using BLAKE3 as the hasher type for `HashBuilder` with non-default hash sizes.
* Make `MD5Result` inherit from `std::array<uint8_t, 16>` which improves & simplifies its API.

Differential Revision: https://reviews.llvm.org/D123100
2022-04-05 21:38:06 -07:00
Mitch Phillips 786c89fed3 [ELF][MTE] Add --android-memtag-* options to synthesize ELF notes
This ELF note is aarch64 and Android-specific. It specifies to the
dynamic loader that specific work should be scheduled to enable MTE
protection of stack and heap regions.

Current synthesis of the ".note.android.memtag" ELF note is done in the
Android build system. We'd like to move that to the compiler. This patch
adds the --memtag-stack, --memtag-heap, and --memtag-mode={async, sync,
none} flags to the linker, which synthesises the note for us.

Future changes will add -fsanitize=memtag* flags to clang which will
pass these through to lld.

Depends on D119381.

Differential Revision: https://reviews.llvm.org/D119384
2022-04-04 11:17:36 -07:00