Commit Graph

7533 Commits

Author SHA1 Message Date
Fangrui Song e3f3d2abf0 [ELF][test] Improve expression test 2022-06-25 21:11:32 -07:00
Fangrui Song 21bf6bb3d3 [ELF] Fix assertion failure when PROVIDE/HIDDEN/PROVIDE_HIDDEN does not have = 2022-06-25 20:26:47 -07:00
Fangrui Song fe0de25b21 [ELF] Allow an expression to follow = in a symbol assignment
GNU ld doesn't require whitespace before =. Match it.
2022-06-25 20:25:34 -07:00
Fangrui Song b0d6dd3905 [ELF] Fix precedence of ? when there are 2 or more operators on the left hand side
For 1 != 1 <= 1 ? 1 : 2, the current code incorrectly considers that ?
has a higher precedence than != (minPrec).

Also, add a test for right associativity.
2022-06-25 13:48:52 -07:00
Fangrui Song d479b2e4db [ELF] Fix precedence of == and != in expressions
In GNU ld, the == and != operators have lower precedence than < > <= >=.
This behavior matches C.
2022-06-25 13:47:32 -07:00
Fangrui Song 4cb05dc3cb [ELF] Support quoted name in the TARGET command 2022-06-25 12:31:20 -07:00
Fangrui Song 363b29567e [ELF] Support quoted symbol in the ENTRY command
This matches GNU ld and matches other places we unquote the symbol name.

Fixes #56208
2022-06-25 12:19:45 -07:00
Fangrui Song c5578fca16 [ELF][test] Improve linkerscript/entry.s 2022-06-25 12:14:47 -07:00
Peter Collingbourne b064bc18c3 ELF: Do not relax ADRP/LDR -> ADRP/ADD for absolute symbols in PIC.
GOT references to absolute symbols can't be relaxed to use ADRP/ADD in
position-independent code because these instructions produce a relative
address.

Differential Revision: https://reviews.llvm.org/D128492
2022-06-24 08:47:23 -07:00
Nico Weber a2c1f7c90d [lld, ELF and mac] Add --time-trace=<file>, remove --time-trace-file=<file>
`--time-trace=foo` has the same behavior as `--time-trace --time-trace-file=<file>`
had previously.

Also, for mac, make --time-trace-granularity *not* imply --time-trace, to match
behavior of the ELF port.

Differential Revision: https://reviews.llvm.org/D128451
2022-06-23 15:46:22 -04:00
Jin Xin Ng 22f1273357
[ThinLTO][ELF] Add --thinlto-emit-index-files option
Allows ThinLTO indices to be written to disk on-the-fly/as-part-of “normal” linker execution. Previously ThinLTO indices could be written via --thinlto-index-only but that would cause the linker to exit early. For MLGO specifically, this enables saving the ThinLTO index files without having to restart the linker to collect data only available at later stages (i.e. output of --save-temps) of the linker's execution.

Note, this option does not currently work with:
--thinlto-object-suffix-replace, as this is intended to be used to consume minimized IR bitcode files while --thinlto-emit-index-files is intended to be run together with InProcessThinLTO (which cannot parse minimized IR).
--thinlto-prefix-replace  support is left unimplemented but can be implemented if needed

Differential Revision: https://reviews.llvm.org/D127777
2022-06-23 12:35:42 -07:00
Daniel Bertalan ed39fd515a [lld-macho] Use source information in duplicate symbol errors
Similarly to how undefined symbol diagnostics were changed in D128184,
we now show where in the source file duplicate symbols are defined at:

  ld64.lld: error: duplicate symbol: _foo
  >> defined in bar.c:42
  >>            /path/to/bar.o
  >> defined in baz.c:1
  >>            /path/to/libbaz.a(baz.o)

For objects that don't contain DWARF data, the format is unchanged.

A slight difference to undefined symbol diagnostics is that we don't
print the name of the symbol on the third line, as it's already
contained on the first line.

Differential Revision: https://reviews.llvm.org/D128425
2022-06-23 11:07:15 -04:00
Fangrui Song 4512dda6af [ELF][test] Clean up thinlto* 2022-06-22 16:19:17 -07:00
Daniel Bertalan 5792797c5b Reland "[lld-macho] Show source information for undefined references"
The error used to look like this:

  ld64.lld: error: undefined symbol: _foo
  >>> referenced by /path/to/bar.o:(symbol _baz+0x4)

If DWARF line information is available, we now show where in the source
the references are coming from:

  ld64.lld: error: unreferenced symbol: _foo
  >>> referenced by: bar.cpp:42 (/path/to/bar.cpp:42)
  >>>                /path/to/bar.o:(symbol _baz+0x4)

The reland is identical to the first time this landed. The fix was in D128294.
This reverts commit 0cc7ad4175.

Differential Revision: https://reviews.llvm.org/D128184
2022-06-21 18:50:06 -04:00
Daniel Bertalan 77b6efbd82 [ADT] [lld-macho] Check for end iterator deref in filter_iterator_base
If ld64.lld was supplied an object file that had a `__debug_abbrev` or
`__debug_str` section, but didn't have any compile unit DIEs in
`__debug_info`, it would dereference an iterator pointing to the empty
array of DIEs. This underlying issue started causing segmentation faults
when parsing for `__debug_info` was addded in D128184. That commit was
reverted, and this one fixes the invalid dereference to allow relanding
it.

This commit adds an assertion to `filter_iterator_base`'s dereference
operators to catch bugs like this one.

Ran check-llvm, check-clang and check-lld.

Differential Revision: https://reviews.llvm.org/D128294
2022-06-21 15:47:45 -04:00
Nico Weber 0cc7ad4175 Revert "[lld-macho] Show source information for undefined references"
This reverts commit cd7624f153.
See https://reviews.llvm.org/D128184#3597534
2022-06-20 19:15:57 -04:00
Daniel Bertalan cd7624f153 [lld-macho] Show source information for undefined references
The error used to look like this:

  ld64.lld: error: undefined symbol: _foo
  >>> referenced by /path/to/bar.o:(symbol _baz+0x4)

If DWARF line information is available, we now show where in the source
the references are coming from:

  ld64.lld: error: unreferenced symbol: _foo
  >>> referenced by: bar.cpp:42 (/path/to/bar.cpp:42)
  >>>                /path/to/bar.o:(symbol _baz+0x4)

Differential Revision: https://reviews.llvm.org/D128184
2022-06-20 18:49:42 -04:00
Jez Ng 8eeede973c [lld-macho][nfc] Tests for -force_load + regular archive load combinations
I realized we'd forgotten to cover this case (though our existing
behavior is indeed correct / matches ld64's).

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D128025
2022-06-16 23:50:07 -04:00
Daniel Bertalan 0eec7e2a89 Reland "[lld-macho] Group undefined symbol diagnostics by symbol".
This reverts commit 36e7c9a450.

This relands d61341768c with the fix described in
https://reviews.llvm.org/D127753#3587390
2022-06-15 19:22:39 -04:00
Stella Stamenova 36e7c9a450 Revert "[lld-macho] Group undefined symbol diagnostics by symbol"
This reverts commit d61341768c.

This change broke multiple lld tests, including some sanitizer builds: https://lab.llvm.org/buildbot/#/builders/5/builds/24787/steps/19/logs/stdio
2022-06-15 15:42:26 -07:00
Keith Smiley 272bf0fc41
[lld-macho] Add support for exporting no symbols
As an optimization for ld64 sometimes it can be useful to not export any
symbols for top level binaries that don't need any exports, to do this
you can pass `-exported_symbols_list /dev/null`, or new with Xcode 14
(ld64 816) there is a `-no_exported_symbols` flag for the same behavior.
This reproduces this behavior where previously an empty exported symbols
list file would have been ignored.

Differential Revision: https://reviews.llvm.org/D127562
2022-06-15 15:07:27 -07:00
Pengxuan Zheng 9db61c3fe1 [LLD][COFF] Convert file name to lowercase when inserting it into visitedLibs
It seems to be a bug in `LinkerDriver::findFile`, the file name is not converted
to lowercase when being inserted into `visitedLibs`. This is the only exception
in the file and all other places always convert file names to lowercase when
inserting them into `visitedLibs` (or `visitedFiles`).

Reviewed By: thieta, hans

Differential Revision: https://reviews.llvm.org/D127709
2022-06-15 09:39:35 -07:00
Martin Storsjö aefa11166f [LLD] [MinGW] Implement --disable-reloc-section, mapped to /fixed
Since binutils 2.36, GNU ld defaults to emitting base relocations,
and that version added the new option --disable-reloc-section to
disable it.

Differential Revision: https://reviews.llvm.org/D127478
2022-06-15 16:51:20 +03:00
Daniel Bertalan d61341768c [lld-macho] Group undefined symbol diagnostics by symbol
ld64.lld used to print the "undefined symbol" line for each reference to
an undefined symbol previously:

  ld64.lld: error: undefined symbol: _foo
  >>> referenced by /path/to/bar.o:(symbol _baz+0x0)

  ld64.lld: error: undefined symbol: _foo
  >>> referenced by /path/to/bar.o:(symbol _quux+0x1)

Now they are deduplicated:

  ld64.lld: error: undefined symbol: _foo
  >>> referenced by /path/to/bar.o:(symbol _baz+0x0)
  >>> referenced by /path/to/bar.o:(symbol _quux+0x1)

As with the other lld ports, only the first 3 references are printed.

Differential Revision: https://reviews.llvm.org/D127753
2022-06-14 16:38:11 -04:00
Daniel Bertalan f2e92cf60e [lld-macho] Print the name of functions containing undefined references
The error used to look like this:

  ld64.lld: error: undefined symbol: _foo
  >>> referenced by /path/to/bar.o

Now it displays the name of the function that contains the undefined
reference as well:

  ld64.lld: error: undefined symbol: _foo
  >>> referenced by /path/to/bar.o:(symbol _baz+0x4)

Differential Revision: https://reviews.llvm.org/D127696
2022-06-14 09:41:28 -04:00
Daniel Bertalan 5f627cc225 [lld-macho] Fix symbol name returned from InputSection::getLocation
This commit fixes the issue that getLocation always printed the name of
the first symbol in the section.

For clarity, upper_bound is used instead of a linear search for finding
the closest symbol name. Note that this change does not affect
performance: this function is only called when printing errors and
`symbols` typically contains a single symbol because of
.subsections_via_symbols.

Differential Revision: https://reviews.llvm.org/D127670
2022-06-13 15:49:27 -04:00
Jez Ng 224094eb44 [lld-macho] Require aarch64 for eh-frame.s test
Should fix the test failure introduced by D124561.
2022-06-13 14:05:07 -04:00
Jez Ng b422dac240 [lld-macho][reland] Support EH frames under arm64
This reverts commit 10641a42e2.

Differential Revision: https://reviews.llvm.org/D124561
2022-06-13 07:45:27 -04:00
Jez Ng e183bf8e15 [lld-macho][reland] Initial support for EH Frames
This reverts commit 942f4e3a7c.

The additional change required to avoid the assertion errors seen
previously is:

  --- a/lld/MachO/ICF.cpp
  +++ b/lld/MachO/ICF.cpp
  @@ -443,7 +443,9 @@ void macho::foldIdenticalSections() {
                                 /*relocVA=*/0);
           isec->data = copy;
         }
  -    } else {
  +    } else if (!isEhFrameSection(isec)) {
  +      // EH frames are gathered as hashables from unwindEntry above; give a
  +      // unique ID to everything else.
         isec->icfEqClass[0] = ++icfUniqueID;
       }
     }

Differential Revision: https://reviews.llvm.org/D123435
2022-06-13 07:45:16 -04:00
Jez Ng d378268ead [lld-macho] Make `--icf=safe` work with LTO
Just matter of enabling the config option.

(Also changed the platform of the input test file to macOS, since that's
the default that we specify in the `%lld` substitution. The conflict was
causing errors when linking with LTO.)

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D127600
2022-06-12 17:26:08 -04:00
Keith Smiley 7d57c69826
[lld-macho] Add support for -w
This flag suppresses warnings produced by the linker. In ld64 this has
an interesting interaction with -fatal_warnings, it silences the
warnings but the link still fails. Instead of doing that here we still
print the warning and eagerly fail the link in case both are passed,
this seems more reasonable so users can understand why the link fails.

Differential Revision: https://reviews.llvm.org/D127564
2022-06-11 17:38:50 -07:00
Sam Clegg 457f38a7b0 [lld][WebAssembly] Revert moving of data relocations to start function
Back in https://reviews.llvm.org/D117412 we moved the application of
data reloctions to the wasm start function.

However, because the dynamic linker doesn't know the final addresses
at module instantiation time, this proved to be too early and the
relocations could be applied with the wrong values.

Fixes: https://github.com/emscripten-core/emscripten/issues/17150

Differential Revision: https://reviews.llvm.org/D127333
2022-06-09 17:49:35 -07:00
Douglas Yung 942f4e3a7c Revert "[lld-macho] Initial support for EH Frames"
This reverts commit 826be330af.

This was causing a test failure on build bots:
  - https://lab.llvm.org/buildbot/#/builders/36/builds/21770
  - https://lab.llvm.org/buildbot/#/builders/58/builds/23913
2022-06-09 05:25:43 -07:00
Douglas Yung 10641a42e2 Revert "[lld-macho] Support EH frames under arm64"
This reverts commit 977d62c33e.

This change was causing crashes in 2 tests on the buildbots:
  - https://lab.llvm.org/buildbot/#/builders/58/builds/23914
  - https://lab.llvm.org/buildbot/#/builders/36/builds/21771
2022-06-09 05:24:28 -07:00
Jez Ng 977d62c33e [lld-macho] Support EH frames under arm64
For arm64, llvm-mc emits relocations for the target function
address like so:

  ltmp:
    <CIE start>
    ...
    <CIE end>
    ... multiple FDEs ...
    <FDE start>
    <target function address - (ltmp + pcrel offset)>
    ...

If any of the FDEs in `multiple FDEs` get dead-stripped, then `FDE start`
will move to an earlier address, and `ltmp + pcrel offset` will no longer
reflect an accurate pcrel value. To avoid this problem, we "canonicalize"
our relocation by adding an `EH_Frame` symbol at `FDE start`, and updating
the reloc to be `target function address - (EH_Frame + new pcrel offset)`.

Reviewed By: #lld-macho, Roger

Differential Revision: https://reviews.llvm.org/D124561
2022-06-08 23:41:29 -04:00
Jez Ng 826be330af [lld-macho] Initial support for EH Frames
== Background ==

`llvm-mc` generates unwind info in both compact unwind and DWARF
formats. LLD already handles the compact unwind format; this diff gets
us close to handling the DWARF format properly.

== Caveats ==

It's not quite done yet, but I figure it's worth getting this reviewed
and landed first as it's shaping up to be a fairly large code change.

**Known limitations of the current code:**

* Only works for x86_64, for which `llvm-mc` emits "abs-ified"
  relocations as described in 618def651b.
  `llvm-mc` emits regular relocations for ARM EH frames, which we do not
  yet handle correctly.

Since the feature is not ready for real use yet, I've gated it behind a
flag that only gets toggled on during test suite runs. With most of the
new code disabled, we see just a hint of perf regression, so I don't
think it'd be remiss to land this as-is:

             base           diff           difference (95% CI)
  sys_time   1.926 ± 0.168  1.979 ± 0.117  [  -1.2% ..   +6.6%]
  user_time  3.590 ± 0.033  3.606 ± 0.028  [  +0.0% ..   +0.9%]
  wall_time  7.104 ± 0.184  7.179 ± 0.151  [  -0.2% ..   +2.3%]
  samples    30             31

== Design ==

Like compact unwind entries, EH frames are also represented as regular
ConcatInputSections that get pointed to via `Defined::unwindEntry`. This
allows them to be handled generically by e.g. the MarkLive and ICF
code. (But note that unlike compact unwind subsections, EH frame
subsections do end up in the final binary.)

In order to make EH frames "look like" a regular ConcatInputSection,
some processing is required. First, we need to split the `__eh_frame`
section along EH frame boundaries rather than along symbol boundaries.
We do this by decoding the length field of each EH frame. Second, the
abs-ified relocations need to be turned into regular Relocs.

== Next Steps ==

In order to support EH frames on ARM targets, we will either have to
teach LLD how to handle EH frames with explicit relocs, or we can try to
make `llvm-mc` emit abs-ified relocs for ARM as well. I'm hoping to do
the latter as I think it will make the LLD implementation both simpler
and faster to execute.

== Misc ==

The `obj-file-with-stabs.s` test had to be updated as the previous
version would trip assertion errors in the code. It appears that in our
attempt to produce a minimal YAML test input, we created a file with
invalid EH frame data. I've fixed this by re-generating the YAML and not
doing any hand-pruning of it.

Reviewed By: #lld-macho, Roger

Differential Revision: https://reviews.llvm.org/D123435
2022-06-08 23:40:52 -04:00
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
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
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
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
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
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
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 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
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
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
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 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
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
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
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
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
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