Commit Graph

14121 Commits

Author SHA1 Message Date
Reid Kleckner e73203a561 [PDB] Check the type server guid when ghashing
Previously we simply didn't check this. Prereq to make the test suite
pass with ghash enabled by default.

Differential Revision: https://reviews.llvm.org/D102885
2021-05-20 16:36:12 -07:00
Martin Storsjö 33b71ec9c6 [LLD] [COFF] Fix automatic export of symbols from LTO objects
Differential Revision: https://reviews.llvm.org/D101569
2021-05-21 00:36:58 +03:00
Wouter van Oortmerssen 3a293cbf13 [WebAssembly] Fix PIC/GOT codegen for wasm64
__table_base is know 64-bit, since in LLVM it represents a function pointer offset
__table_base32 is a copy in wasm32 for use in elem init expr, since no truncation may be used there.
New reloc R_WASM_TABLE_INDEX_REL_SLEB64 added

Differential Revision: https://reviews.llvm.org/D101784
2021-05-20 09:59:31 -07:00
Sam Clegg 356b85edd7 [lld][WebAssembly] Fix for string tail merging and -r/--relocatable
Ensure that both SyntheticMergedChunk and all MergeInfoChunks that it
comprises are assigned the correct output section.  Without this we
would crash when outputting relocations in --relocatable mode.

Fixes: https://github.com/emscripten-core/emscripten/issues/14220

Differential Revision: https://reviews.llvm.org/D102806
2021-05-19 15:25:58 -07:00
Reid Kleckner 12dd8df38b [PDB] Do not record PGO or coverage public symbols
These symbols are long, and they tend to cause the PDB file size to
overflow. They are generally not necessary when debugging problems in
user code.

This change reduces the size of chrome.dll.pdb with coverage from
6,937,108,480 bytes to 4,690,210,816 bytes.

Differential Revision: https://reviews.llvm.org/D102719
2021-05-19 12:41:31 -07:00
Nico Weber fd09a764eb [lld/mac] Remove dead declaration 2021-05-19 14:18:03 -04:00
Mariusz Ceier 9383e9c1e6 Fix lld macho standalone build by including llvm/Config/llvm-config.h instead of llvm/Config/config.h
lld/MachO/Driver.cpp and lld/MachO/SyntheticSections.cpp include
llvm/Config/config.h which doesn't exist when building standalone lld.

This patch replaces llvm/Config/config.h include with llvm/Config/llvm-config.h
just like it is in lld/ELF/Driver.cpp and HAVE_LIBXAR with LLVM_HAVE_LIXAR and
moves LLVM_HAVE_LIBXAR from config.h to llvm-config.h

Also it adds LLVM_HAVE_LIBXAR to LLVMConfig.cmake and links liblldMachO2.so
with XAR_LIB if LLVM_HAVE_LIBXAR is set.

Differential Revision: https://reviews.llvm.org/D102084
2021-05-19 11:15:07 -04:00
Reid Kleckner ac2226b0f5 [PDB] Improve error handling when writes fail
Handle PDB writing errors like any other error in LLD: emit an error and
continue. This allows the linker to print timing data and summary data
after linking, which can be helpful for finding PDB size problems. Also
report how large the file would have been.

Example output:

lld-link: error: Output data is larger than 4 GiB. File size would have been 6,937,108,480
lld-link: error: failed to write PDB file ./chrome.dll.pdb
                                    Summary
--------------------------------------------------------------------------------
          33282 Input OBJ files (expanded from all cmd-line inputs)
              4 PDB type server dependencies
              0 Precomp OBJ dependencies
       33396931 Input type records
... snip ...
  Input File Reading:           59756 ms ( 45.5%)
  GC:                            7500 ms (  5.7%)
  ICF:                           3336 ms (  2.5%)
  Code Layout:                   6329 ms (  4.8%)
  PDB Emission (Cumulative):    46192 ms ( 35.2%)
    Add Objects:                27609 ms ( 21.0%)
      Type Merging:             16740 ms ( 12.8%)
      Symbol Merging:           10761 ms (  8.2%)
    Publics Stream Layout:       9383 ms (  7.1%)
    TPI Stream Layout:           1678 ms (  1.3%)
    Commit to Disk:              3461 ms (  2.6%)
--------------------------------------------------
Total Link Time:               131244 ms (100.0%)

Differential Revision: https://reviews.llvm.org/D102713
2021-05-18 13:17:17 -07:00
Sam Clegg 876d49baad [lld][WebAssembly] Convert test to assembly. NFC.
Differential Revision: https://reviews.llvm.org/D102704
2021-05-18 12:31:13 -07:00
Sam Clegg 45b7cf9955 [lld][WebAssembly] Enable string tail merging in debug sections
This is a followup to https://reviews.llvm.org/D97657 which
applied string tail merging to data segments.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=48828

Differential Revision: https://reviews.llvm.org/D102436
2021-05-18 12:25:39 -07:00
Nico Weber b4ead2c37b [lld/mac] Correctly set nextdefsym
In LC_DYSYMTAB, private externs were still emitted as exported symbols instead
of as locals.

Fixes PR50373. See bug for details.

Differential Revision: https://reviews.llvm.org/D102662
2021-05-18 13:53:55 -04:00
Martin Storsjö dd7575ba44 [LLD] [MinGW] Pass the canExitEarly parameter through properly
The MinGW driver passed a hardcoded true to this parameter
since 6f4e255219, but when the MinGW driver got the
canExitEarly parameter for consistency in b11386f9be, this
call was missed so it wasn't passed on properly.
2021-05-18 15:09:07 +03:00
Nico Weber 095c520fb4 [lld/mac] Propagate -(un)exported_symbol(s_list) to privateExtern in Driver
That way, it's done only once instead of every time shouldExportSymbol() is
called.

Possibly a bit faster:

    % ministat at_main at_symtodo
    x at_main
    + at_symtodo
        N           Min           Max        Median           Avg        Stddev
    x  30     3.9732189      4.114846      4.024621     4.0304692   0.037022865
    +  30       3.93766     4.0510042     3.9973931      3.991469   0.028472565
    Difference at 95.0% confidence
            -0.0390002 +/- 0.0170714
            -0.967635% +/- 0.423559%
            (Student's t, pooled s = 0.0330256)

In other runs with n=30 it makes no perf difference, so maybe it's just noise.
But being able to quickly and conveniently answer "is this symbol exported?"
is useful for fixing PR50373 and for implementing -dead_strip, so this seems
like a good change regardless.

No behavior change.

Differential Revision: https://reviews.llvm.org/D102661
2021-05-18 07:42:58 -04:00
Alexander Shaposhnikov dc2c6cf274 [lld][MachO] Adjust isCodeSection signature
This diff changes the type of the argument of isCodeSection to const InputSection *.
NFC.

Test plan: make check-lld-macho

Differential revision: https://reviews.llvm.org/D102664
2021-05-17 22:09:47 -07:00
Sam Clegg 5a9b25e15b [lld][WebAssembly] Refactor input chunk class hierarchy. NFC
The main motivation for this refactor is to remove the subclass
relationship between the InputSegment and MergeInputSegment and
SyntenticMergedInputSegment so that we can use the merging classes for
debug sections which are not data segments.

In the process of refactoring I also remove all the virtual functions
from the class hierarchy and try to reuse techniques used in the ELF
linker (see `lld/ELF/InputSections.h`).

Differential Revision: https://reviews.llvm.org/D102546
2021-05-17 21:01:17 -07:00
Nico Weber bc588f9961 [lld/mac] Inline a check
`match()` can only return for non-empty vectors, but at least in
non-LTO builds that isn't clear to the compiler. Help it out.
This is a minor but measurable speedup on my machine (but less
than what we might've lost in https://reviews.llvm.org/D100818#2764272 --
bot note higher N on this measurement here, so higher confidence here):

    % ministat at_main at_branch
    x at_main
    + at_branch
        N           Min           Max        Median           Avg        Stddev
    x  30     3.9243979     4.0395119      3.987375     3.9826236   0.027567796
    +  30     3.8495831     4.0009291      3.931325     3.9347135   0.037832878
    Difference at 95.0% confidence
            -0.0479101 +/- 0.0171102
            -1.20298% +/- 0.429622%
            (Student's t, pooled s = 0.0331007)

No behavior change.

Eventually we should apply these lists at symbol parse time instead of
every time shouldExportSymbol() though :)

Differential Revision: https://reviews.llvm.org/D102655
2021-05-17 20:04:45 -04:00
Markus Böck 65271ffe84 [lld][MinGW] Introduce aliases for -Bdynamic and -Bstatic
Besides -Bdynamic and -Bstatic, ld documents additional aliases for both of these options. Instead of -Bstatic, one may write -dn, -non_shared or -static. Instead of -Bdynamic one may write -dy or -call_shared. Source: https://sourceware.org/binutils/docs-2.36/ld/Options.html

This patch adds those aliases to the MinGW driver of lld for the sake of ld compatibility.

Encountered this case while compiling a static Qt 6.1 distribution and got build failures as -static was passed directly to the linker, instead of through the compiler driver.

Differential Revision: https://reviews.llvm.org/D102637
2021-05-17 22:13:26 +02:00
Nico Weber 4a12248ee2 [lld/mac] Honor REFERENCED_DYAMICALLY, set it on __mh_execute_header
Has the effect that `__mh_execute_header` stays in the symbol table of
outputs even after running `strip` on the output. I don't know if that's
important for anything -- my motivation for the patch is just is to make
the output more similar to ld64.

(Corresponds to symbolTableInAndNeverStrip in ld64.)

Differential Revision: https://reviews.llvm.org/D102619
2021-05-17 14:22:12 -04:00
Mateusz Mikuła 84306ef9c4 [LLD][MinGW] Add --fatal-warnings and --no-fatal-warnings flags
Differential Revision: https://reviews.llvm.org/D102514
2021-05-17 10:40:31 +03:00
Harald van Dijk d62413452f
[lld][X86] Restore gotEntrySize.
D62727 removed GotEntrySize and GotPltEntrySize with a comment that they
are always equal to wordsize(), but that is not entirely true: X32 has a
word size of 4, but needs 8-byte GOT entries. This restores gotEntrySize
for both, adjusted for current naming conventions, but defaults it to
config->wordsize to keep things simple for architectures other than
x86_64.

This partially reverts D62727.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D102509
2021-05-17 00:13:00 +01:00
Sam Clegg 119f61af3a [lld][WebAssembly] Remove unused method declaration. NFC
This method was removed in https://reviews.llvm.org/D102265
but the declaration was missed.
2021-05-14 15:54:33 -07:00
Mateusz Mikuła f84a4cb0df [LLD][MinGW] Ignore --no-undefined flag
AFAIK this is the default behaviour when this flag is not passed.

Differential Revision: https://reviews.llvm.org/D102516
2021-05-14 23:47:50 +03:00
Fangrui Song 5741dc87a5 [test] Improve x86-64-plt.s 2021-05-14 10:38:40 -07:00
Fangrui Song 4adf7a7604 [ELF] Add -Bno-symbolic
This option will be available in GNU ld 2.27 (https://sourceware.org/bugzilla/show_bug.cgi?id=27834).
This option can cancel previously specified -Bsymbolic and
-Bsymbolic-functions.  This is useful for excluding some links when the
default uses -Bsymbolic-functions.

Reviewed By: jhenderson, peter.smith

Differential Revision: https://reviews.llvm.org/D102383
2021-05-14 09:40:32 -07:00
Fangrui Song da9b6d0656 [ELF][test] Improve -Bsymbolic & -Bsymbolic-functions test
Previously there was no test checking that -Bsymbolic-functions only applies to STT_FUNC symbols.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D102461
2021-05-14 09:33:43 -07:00
Reid Kleckner ee23f8b36f [COFF] Remove a truncation assertion from setRVA
LLD already produces a nice error message when sections exceed 4GB, and
this setRVA assertion causes LLD to crash instead of diagnosing the
error properly.

No test because we don't want slow tests that create 4GB files.
2021-05-13 19:37:14 -07:00
Sam Clegg cd01430ff1 [lld][WebAssembly] Allow data symbols to extend past end of segment
This fixes a bug with string merging with string symbols that contain
NULLs, as is the case in the `merge-string.s` test.

The bug only showed when we run with `--relocatable` and then try read
the resulting object back in.  In this case we would end up with string
symbols that extend past the end of the segment in which they live.

The problem comes from the fact that sections which are flagged as
string mergable assume that all strings are NULL terminated.  The
merging algorithm will drop trailing chars that follow a NULL since they
are essentially unreachable.  However, the "size" attribute (in the
symbol table) of such a truncated symbol is not updated resulting a
symbol size that can overlap the end of the segment.

I verified that this can happen in ELF too given the right conditions
and the its harmless enough.  In practice Strings that contain embedded
null should not be part of a mergable section.

Differential Revision: https://reviews.llvm.org/D102281
2021-05-12 13:43:37 -07:00
Sam Clegg 3041b16f73 [WebAssembly] Add TLS data segment flag: WASM_SEG_FLAG_TLS
Previously the linker was relying solely on the name of the segment
to imply TLS.

Differential Revision: https://reviews.llvm.org/D102202
2021-05-12 13:31:02 -07:00
Fangrui Song a8053399cd [ELF][AVR] Add explicit relocation types to getRelExpr 2021-05-12 12:38:27 -07:00
Martin Storsjö 7e0768329c [LLD] [COFF] Fix including the personality function for DWARF EH when linking with --gc-sections
Since c579a5b1d9 we don't traverse
.eh_frame when doing GC. But the exception handling personality
function needs to be included, and is only referenced from within
.eh_frame.

Differential Revision: https://reviews.llvm.org/D102138
2021-05-12 22:23:01 +03:00
Shoaib Meenai 56f7e5a822 [cmake] Add support for multiple distributions
LLVM's build system contains support for configuring a distribution, but
it can often be useful to be able to configure multiple distributions
(e.g. if you want separate distributions for the tools and the
libraries). Add this support to the build system, along with
documentation and usage examples.

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D89177
2021-05-12 11:13:18 -07:00
Greg McGary 93c8559baf [lld-macho] Implement branch-range-extension thunks
Extend the range of calls beyond an architecture's limited branch range by first calling a thunk, which loads the far address into a scratch register (x16 on ARM64) and branches through it.

Other ports (COFF, ELF) use multiple passes with successively-refined guesses regarding the expansion of text-space imposed by thunk-space overhead. This MachO algorithm places thunks during MergedOutputSection::finalize() in a single pass using exact thunk-space overheads. Thunks are kept in a separate vector to avoid the overhead of inserting into the `inputs` vector of `MergedOutputSection`.

FIXME:
* arm64-stubs.s test is broken
* add thunk tests
* Handle thunks to DylibSymbol in MergedOutputSection::finalize()

Differential Revision: https://reviews.llvm.org/D100818
2021-05-12 09:44:58 -07:00
Sam Clegg 19cedd3cd3 [lld][WebAssembly] Fix for string merging + negative addends
Don't include the relocation addend when calculating the
virtual address of a symbol.  Instead just pass the symbol's
offset and add the addend afterwards.

Without this fix we hit the `offset is outside the section`
error in MergeInputSegment::getSegmentPiece.

This fixes a real world error we were are seeing in emscripten.

Differential Revision: https://reviews.llvm.org/D102271
2021-05-11 17:47:57 -07:00
Sam Clegg b49a798e71 [lld][WebAssembly] Remove relocation target verification
We have this extra step in wasm-ld that doesn't exist in other lld
backend which verifies the existing contents of the relocation targets.
This was originally intended as an extra form of double checking and an
aid to compiler developers.   However it has always been somewhat
controversial and there have been suggestions in the past the we simply
remove it.

My motivation for removing it now is that its causing me a headache
when trying to fix an issue with negative addends.  In the case of
negative addends that final result can be wrapped/negative but this
checking code would require significant modification to be able to deal
with that case.  For example with some test cases I'm looking at I'm
seeing error like this:

```
wasm-ld: warning: /usr/local/google/home/sbc/dev/wasm/llvm-build/tools/lld/test/wasm/Output/merge-string.s.tmp.o:(.rodata_relocs): unexpected existing value for R_WASM_MEMORY_ADDR_I32: existing=FFFFFFFA expected=FFFFFFFFFFFFFFFA
```

Rather than try to refactor `calcExpectedValue` to somehow return two
different types of results (32 and 64-bit) depending on the relocation
type, I think we can just remove this code.

Differential Revision: https://reviews.llvm.org/D102265
2021-05-11 12:05:14 -07:00
Sam Clegg b2f227c6c8 [lld][WebAssembly] Convert test to assembly. NFC.
Differential Revision: https://reviews.llvm.org/D102264
2021-05-11 11:37:53 -07:00
Nico Weber 9ab49ae55d [lld/mac] Implement -sectalign
clang sometimes passes this flag along (see D68351), so we should implement it.

Differential Revision: https://reviews.llvm.org/D102247
2021-05-11 13:31:32 -04:00
Martin Storsjö 518b7f9135 [LLD] [COFF] Add an assert regarding the RVA of exported symbols. NFC.
As this isn't handled as a regular relocation, the normal handling of
maybeReportRelocationToDiscarded in Chunks.cpp doesn't apply here.

This would have caught the issue fixed by
82de4e0753.

Differential Revision: https://reviews.llvm.org/D102115
2021-05-11 13:04:01 +03:00
Igor Kudrin 70c23e232e [LLD] Improve reporting unresolved symbols in shared libraries
Currently, when reporting unresolved symbols in shared libraries, if an
undefined symbol is firstly seen in a regular object file that shadows
the reference for the same symbol in a shared object. As a result, the
error for the unresolved symbol in the shared library is not reported.
If referencing sections in regular object files are discarded because of
'--gc-sections', no reports about such symbols are generated, and the
linker finishes successfully, generating an output image that fails on
the run.

The patch fixes the issue by keeping symbols, which should be checked,
for each shared library separately.

Differential Revision: https://reviews.llvm.org/D101996
2021-05-11 12:48:29 +07:00
Sam Clegg 3b8d2be527 Reland: "[lld][WebAssembly] Initial support merging string data"
This change was originally landed in: 5000a1b4b9
It was reverted in: 061e071d8c

This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657
2021-05-10 16:03:38 -07:00
Nico Weber 061e071d8c Revert "[lld][WebAssembly] Initial support merging string data"
This reverts commit 5000a1b4b9.
Breaks tests, see https://reviews.llvm.org/D97657#2749151

Easily repros locally with `ninja check-llvm-mc-webassembly`.
2021-05-10 18:28:28 -04:00
Sam Clegg 5000a1b4b9 [lld][WebAssembly] Initial support merging string data
This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657
2021-05-10 13:15:12 -07:00
Jez Ng b1c3c2e4fc [lld-macho] Fix order file arch filtering
We had a hardcoded check and a stale TODO, written back when we only had
support for one architecture.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D102154
2021-05-10 15:45:54 -04:00
Jez Ng 2516b0b526 [lld-macho] Treat undefined symbols uniformly
In particular, we should apply the `-undefined` behavior to all
such symbols, include those that are specified via the command line
(i.e.  `-e`, `-u`, and `-exported_symbol`). ld64 supports this too.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D102143
2021-05-10 15:45:54 -04:00
Jez Ng 3d5e5066f1 [lld-macho][nfc] Clean up tests
* Remove unnecessary `rm -rf %t`s
* Have lc-linker-option.ll use the right comment marker
2021-05-10 15:45:54 -04:00
Fangrui Song 1f44fee521 [lld-macho] Improve an external weak def test
The rebase table entry is untested.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D102150
2021-05-10 10:35:44 -07:00
Sam Clegg bda8b84884 [lld][WebAssembly] Disallow exporting of TLS symbols
Cross module TLS is currently not supported by our ABI.  This
change makes explicitly exporting a TLS symbol into an error
and prevents implicit exporting (via --export-all).

See https://github.com/emscripten-core/emscripten/issues/14120

Differential Revision: https://reviews.llvm.org/D102044
2021-05-10 09:58:44 -07:00
Fangrui Song 7a0231ae59 [llvm-objdump][MachO] Print a newline before lazy bind/bind/weak/exports trie
This adds a separator between two pieces of information.

Reviewed By: #lld-macho, alexshap

Differential Revision: https://reviews.llvm.org/D102114
2021-05-10 09:16:18 -07:00
Jez Ng 75f74f2673 [lld-macho] Add llvm-otool as a test dependency
This unbreaks my local build, which is configured to build only parts of
LLVM.
2021-05-09 21:12:58 -04:00
Nico Weber 7f673fcaa9 [lld/mac] Fix alignment on subsections
On a section with alignment of 16, subsections aligned to 16-byte
boundaries should keep their 16-byte alignment.

Fixes PR50274. (The same bug could have happened with -order_file
previously.)

Differential Revision: https://reviews.llvm.org/D102139
2021-05-09 21:00:56 -04:00
Jez Ng 0f8854f7f5 [lld-macho] Don't reference entry symbol for non-executables
This would cause us to pull in symbols (and code) that should
be unused.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D102137
2021-05-09 20:30:26 -04:00