Commit Graph

14981 Commits

Author SHA1 Message Date
Keith Smiley a6298fb160 [lld-macho] Add support for -add_empty_section
This is a ld64 option equivalent to `-sectcreate seg sect /dev/null`
that's useful for creating sections like the RESTRICT section.

Differential Revision: https://reviews.llvm.org/D117749
2022-01-30 10:03:41 -08:00
Keith Smiley 0ab09a9009 [test][lld-macho] Improve LC_FUNCTION_STARTS test coverage
Previously functions that aren't included in the symtab were also
excluded from the function starts. Symbols missing from function starts
degrades the debugger experience in the case you don't have debug info
for them.

Differential Revision: https://reviews.llvm.org/D114275
2022-01-30 09:46:36 -08:00
Fangrui Song 5a2020d069 [ELF] copyShtGroup: replace unordered_set<uint32_t> with DenseSet<uint32_t>. NFC
We don't need to support the empty/tombstone key section index.
2022-01-30 01:18:41 -08:00
Fangrui Song f318fd9bf8 [ELF] crtbegin/crtend test: replace std::regex with hand-written matcher. NFC
My x86-64 lld executable is 18KiB smaller.
2022-01-30 01:11:19 -08:00
Fangrui Song a7f9c002cd [ELF][test] Test {crtbegin,crtend}{S,T}.o 2022-01-30 01:08:10 -08:00
Fangrui Song fcd8817da5 [ELF] Simplify maybeCompress with lld::split. NFC 2022-01-30 00:44:19 -08:00
Fangrui Song bc1369fae3 [ELF] Optimize MergeInputSection::splitNonStrings with resize_for_overwrite. NFC 2022-01-30 00:10:52 -08:00
Fangrui Song 988a03c585 [ELF] Add some Mips*Section to InStruct and change make<Mips*Section> to std::make_unique
Similar to D116143. My x86-64 lld executable is 20+KiB smaller.
2022-01-29 23:55:29 -08:00
Fangrui Song c0b986aa0c [ELF] Remove make<std::unique_ptr<MemoryBuffer>>. NFC 2022-01-29 23:35:15 -08:00
Fangrui Song 8d8fce87bb [ELF] De-template getErrorPlace. NFC 2022-01-29 23:05:54 -08:00
Fangrui Song 72a005bf19 [ELF] De-template getAndFeatures. NFC 2022-01-29 20:11:59 -08:00
Fangrui Song d754c0b64f [ELF] Make errorOrWarn opaque to decrease code size. NFC
In my x86-64 lld, .text is -3.08Ki smaller.
2022-01-29 19:31:09 -08:00
Fangrui Song ee647d4c96 [ELF] Optimize obj.getSectionIndex. NFC 2022-01-29 18:01:58 -08:00
Fangrui Song 5d00d37617 [ELF] Simplify eSyms. NFC 2022-01-29 17:00:38 -08:00
Fangrui Song d86435c230 [ELF] createInputSection: remove unneeded argument. NFC 2022-01-29 16:52:32 -08:00
Fangrui Song ee7720acd6 [ELF] Avoid repeated getObj construction in getSectionIndex. NFC 2022-01-29 16:51:00 -08:00
Fangrui Song 94e97e668c [ELF] Reorder InputSectionBase::parent. NFC
Move it before others.
2022-01-29 16:20:40 -08:00
Fangrui Song b204d7c459 [ELF] Reorder InputFile members. NFC
`symbols` is used frequently. Moving it before others can decrease offsets.
2022-01-29 16:10:52 -08:00
Fangrui Song 469c4124ab [ELF] --gdb-index: switch to SmallVector. NFC 2022-01-29 15:24:56 -08:00
Fangrui Song da0e5b885b [ELF] Refactor -z combreloc
* `RelocationBaseSection::addReloc` increases `numRelativeRelocs`, which
  duplicates the work done by RelocationSection<ELFT>::writeTo.
* --pack-dyn-relocs=android has inappropropriate DT_RELACOUNT.
  AndroidPackedRelocationSection does not necessarily place relative relocations
  in the front and DT_RELACOUNT might cause semantics error (though our
  implementation doesn't and Android bionic doesn't use DT_RELACOUNT anyway.)

Move `llvm::partition` to a new function `partitionRels` and compute
`numRelativeRelocs` there. Now `RelocationBaseSection::addReloc` is trivial and
can be moved to the header to enable inlining.

The rest of DynamicReloc and `-z combreloc` handling is moved to the
non-template `RelocationBaseSection::computeRels` to decrease code size. My
x86-64 lld executable is 44+KiB smaller.

While here, rename `sort` to `combreloc`.
2022-01-29 14:45:58 -08:00
Mateusz Mikuła 460830a9c6 [LLD][MinGW] Add --heap argument support
Noticed in https://github.com/msys2/MINGW-packages/pull/10567.

Differential Revision: https://reviews.llvm.org/D118405
2022-01-30 00:01:45 +02:00
Fangrui Song f097c108b8 [ELF][test] Improve INSERT [AFTER|BEFORE] and adjustSectionsBeforeSorting tests 2022-01-28 22:21:13 -08:00
Petr Hosek 71dcd9bd04 [ELF] Change the search order for dependent libraries
When processing dependent libraries, if there's a directory of the same
name as the library being searched for, either in the current directory
or earlier in the search order, LLD will try to open it and report an
error. This is because LLD uses file existence check. To address this
issue we reverse the order, searching the library by basename first
and only considering search paths later, and current directory last.

Differential Revision: https://reviews.llvm.org/D118498
2022-01-28 20:46:01 -08:00
Fangrui Song 33b38339a0 [lld] Add module name to LTO inline asm diagnostic
Close #52781: for LTO, the inline asm diagnostic uses `<inline asm>` as the file
name (lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp) and it is unclear which
module has the issue.

With this patch, we will see the module name (say `asm.o`) before `<inline asm>` with ThinLTO.

```
% clang -flto=thin -c asm.c && myld.lld asm.o -e f
ld.lld: error: asm.o <inline asm>:1:2: invalid instruction mnemonic 'invalid'
        invalid
        ^~~~~~~
```

For regular LTO, unfortunately the original module name is lost and we only get
ld-temp.o.

Reviewed By: #lld-macho, ychen, Jez Ng

Differential Revision: https://reviews.llvm.org/D118434
2022-01-28 11:32:42 -08:00
Roger Kim 422084332a [lld][Macho] Include dead-stripped symbols in mapfile
ld64 outputs dead stripped symbols when using the -dead-strip flag. This change mimics that behavior for lld.

ld64's -dead_strip flag outputs:
```
$ ld -map map basics.o -o out -dead_strip -L/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib -lSystem
$ cat map
# Path: out
# Arch: x86_64
# Object files:
[  0] linker synthesized
[  1] basics.o
# Sections:
# Address       Size            Segment Section
0x100003F97     0x00000021      __TEXT  __text
0x100003FB8     0x00000048      __TEXT  __unwind_info
0x100004000     0x00000008      __DATA_CONST    __got
0x100008000     0x00000010      __DATA  __ref_section
0x100008010     0x00000001      __DATA  __common
# Symbols:
# Address       Size            File  Name
0x100003F97     0x00000006      [  1] _ref_local
0x100003F9D     0x00000001      [  1] _ref_private_extern
0x100003F9E     0x0000000C      [  1] _main
0x100003FAA     0x00000006      [  1] _no_dead_strip_globl
0x100003FB0     0x00000001      [  1] _ref_from_no_dead_strip_globl
0x100003FB1     0x00000006      [  1] _no_dead_strip_local
0x100003FB7     0x00000001      [  1] _ref_from_no_dead_strip_local
0x100003FB8     0x00000048      [  0] compact unwind info
0x100004000     0x00000008      [  0] non-lazy-pointer-to-local: _ref_com
0x100008000     0x00000008      [  1] _ref_data
0x100008008     0x00000008      [  1] l_ref_data
0x100008010     0x00000001      [  1] _ref_com

# Dead Stripped Symbols:
#               Size            File  Name
<<dead>>        0x00000006      [  1] _unref_extern
<<dead>>        0x00000001      [  1] _unref_local
<<dead>>        0x00000007      [  1] _unref_private_extern
<<dead>>        0x00000001      [  1] _ref_private_extern_u
<<dead>>        0x00000008      [  1] _unref_data
<<dead>>        0x00000008      [  1] l_unref_data
<<dead>>        0x00000001      [  1] _unref_com
```

Reviewed By: int3, #lld-macho, thevinster

Differential Revision: https://reviews.llvm.org/D114737
2022-01-28 10:51:27 -08:00
Alexander Shaposhnikov 0d71f2e097 [lld][ELF] Cleanup %t directory in tests, NFC 2022-01-28 08:41:52 +00:00
Sam Clegg 875ee937ae [lld][WebAssembly] Handle TLS symbols in older object file
In older versions of llvm (e.g. llvm 13), symbols were not individually
flagged as TLS.  In this case, the indent was to implicitly mark any
symbols defined in TLS segments as TLS.  However, we were not performing
this implicit conversion if the segment was explicitly marked as TLS

As it happens, llvm 13 was branched between the addition of the segment
flag and the addition of the symbol flag. See:

- segment flag added: https://reviews.llvm.org/D102202
- symbol flag added: https://reviews.llvm.org/D109426

Testing this is tricky because the assembler will imply the TLS status
of the symbol based on the segment its declared in, so we are forced to
use a yaml file here.

Fixes: https://github.com/emscripten-core/emscripten/issues/15891

Differential Revision: https://reviews.llvm.org/D118414
2022-01-27 17:27:09 -08:00
Fangrui Song 3bc152769d [ELF] Parallelize computeIsPreemptible 2022-01-26 23:45:04 -08:00
Fangrui Song 1372d53639 [ELF] Optimize two vector. NFC 2022-01-26 23:10:40 -08:00
Fangrui Song afeb4a6628 [ELF] Optimize -Map. NFC
getVA is slow. Avoid calling it in the llvm::sort comparator.
2022-01-26 22:51:31 -08:00
Fangrui Song 14b7785c09 [ELF] Simplify InputSection::writeTo. NFC 2022-01-26 22:03:26 -08:00
Fangrui Song 913914f0f8 [ELF] Simplify writing the Elf_Chdr header. NFC
And avoiding changing `size` in `writeTo`.
2022-01-26 10:23:56 -08:00
Benjamin Kramer f15014ff54 Revert "Rename llvm::array_lengthof into llvm::size to match std::size from C++17"
This reverts commit ef82063207.

- It conflicts with the existing llvm::size in STLExtras, which will now
  never be called.
- Calling it without llvm:: breaks C++17 compat
2022-01-26 16:55:53 +01:00
serge-sans-paille ef82063207 Rename llvm::array_lengthof into llvm::size to match std::size from C++17
As a conquence move llvm::array_lengthof from STLExtras.h to
STLForwardCompat.h (which is included by STLExtras.h so no build
breakage expected).
2022-01-26 16:17:45 +01:00
Fangrui Song 3704abaa16 [ELF] --gdb-index: replace vector<uint8_t> with unique_ptr<uint8_t[]>. NFC 2022-01-25 23:53:23 -08:00
Fangrui Song 571d6a7120 [ELF] Optimize .relr.dyn to not grow vector<uint64_t>. NFC 2022-01-25 23:33:40 -08:00
Fangrui Song 9fac78d0e1 [ELF] Simplify and optimize .relr.dyn NFC 2022-01-25 22:50:03 -08:00
Fangrui Song 2a80c3dbe1 [ELF] Clarify that Z_BEST_SPEED==1 in a comment. NFC 2022-01-25 22:40:53 -08:00
Fangrui Song 07bd467643 [ELF] --build-id: replace vector<uint8_t> with unique_ptr<uint8_t[]>. NFC
We can't use C++20 make_unique_for_overwrite yet.
2022-01-25 22:39:43 -08:00
Fangrui Song 7438dbe078 [ELF] Cast size to size_t. NFC
To fix

../../chromeclang/bin/../include/c++/v1/__algorithm/min.h:39:1: note: candidate template ignored: deduced conflicting types for parameter '_Tp' ('unsigned long' vs. 'unsigned long long')

on macOS arm64.
2022-01-25 22:38:24 -08:00
Fangrui Song 223f9dea3d [ELF] maybeCompress: replace vector<uint8_t> with unique_ptr<uint8_t[]>. NFC
And mention that it is zero-initialized. I do not notice a speed-up if
changed to be uninitialized by forcing the zero filler in writeTo.
2022-01-25 22:15:44 -08:00
Puyan Lotfi 227d18b3a8 [lld][macho][NFC] Make MachO/start-end.s test less britle by checking for _main:
In start-end.s there is a lit check line `# SEG: _main` to begin the
check at the start of the function main where `_main` is the Darwin name
mangling for C main. Because the text file that FileCheck is getting as
input has the path of the compiler build in it from llvm-mc and
llvm-objdump, and because of the lack of a trailing colon in this check
line we end up inadvertently matching against the line of text with the
compiler path in it in the case where said path contains "_main" some
place. This can be very likely if the compiler branch has "main" or
"_main" in it.

To fix this I include the training : since that will match on the
function label and not the path line.
2022-01-25 19:23:51 -08:00
Fangrui Song 4cdc441690 [ELF] Parallelize --compress-debug-sections=zlib
When linking a Debug build clang (265MiB SHF_ALLOC sections, 920MiB uncompressed
debug info), in a --threads=1 link "Compress debug sections" takes 2/3 time and
in a --threads=8 link "Compress debug sections" takes ~70% time.

This patch splits a section into 1MiB shards and calls zlib `deflake` parallelly.

DEFLATE blocks are a bit sequence. We need to ensure every shard starts
at a byte boundary for concatenation. We use Z_SYNC_FLUSH for all shards
but the last to flush the output to a byte boundary. (Z_FULL_FLUSH can
be used as well, but Z_FULL_FLUSH clears the hash table which just
wastes time.)

The last block requires the BFINAL flag. We call deflate with Z_FINISH
to set the flag as well as flush the output to a byte boundary. Under
the hood, all of Z_SYNC_FLUSH, Z_FULL_FLUSH, and Z_FINISH emit a
non-compressed block (called stored block in zlib). RFC1951 says "Any
bits of input up to the next byte boundary are ignored."

In a --threads=8 link, "Compress debug sections" is 5.7x as fast and the total
speed is 2.54x. Because the hash table for one shard is not shared with the next
shard, the output is slightly larger. Better compression ratio can be achieved
by preloading the window size from the previous shard as dictionary
(`deflateSetDictionary`), but that is overkill.

```
# 1MiB shards
% bloaty clang.new -- clang.old
    FILE SIZE        VM SIZE
 --------------  --------------
  +0.3%  +129Ki  [ = ]       0    .debug_str
  +0.1%  +105Ki  [ = ]       0    .debug_info
  +0.3%  +101Ki  [ = ]       0    .debug_line
  +0.2% +2.66Ki  [ = ]       0    .debug_abbrev
  +0.0% +1.19Ki  [ = ]       0    .debug_ranges
  +0.1%  +341Ki  [ = ]       0    TOTAL

# 2MiB shards
% bloaty clang.new -- clang.old
    FILE SIZE        VM SIZE
 --------------  --------------
  +0.2% +74.2Ki  [ = ]       0    .debug_line
  +0.1% +72.3Ki  [ = ]       0    .debug_str
  +0.0% +69.9Ki  [ = ]       0    .debug_info
  +0.1%    +976  [ = ]       0    .debug_abbrev
  +0.0%    +882  [ = ]       0    .debug_ranges
  +0.0%  +218Ki  [ = ]       0    TOTAL
```

Bonus in not using zlib::compress

* we can compress a debug section larger than 4GiB
* peak memory usage is lower because for most shards the output size is less
  than 50% input size (all less than 55% for a large binary I tested, but
  decreasing the initial output size does not decrease memory usage)

Reviewed By: ikudrin

Differential Revision: https://reviews.llvm.org/D117853
2022-01-25 10:29:04 -08:00
Leonard Grey a5c9d71780 [lld-macho] Move order file and call graph sorting into SectionPriorities
See https://reviews.llvm.org/D117354 for context and discussion.
2022-01-25 12:18:15 -05:00
Leonard Grey f23d57a632 [lld-macho] Rename CallGraphSort.{h,cpp} to SectionPriorities
This is in preparation for moving the code that parses and processes
order files into this file.

See https://reviews.llvm.org/D117354 for context and discussion.
2022-01-25 12:15:14 -05:00
Fangrui Song c03fdd3403 [ELF] Fix the branch range computation when reusing a thunk
Notation: dst is `t->getThunkTargetSym()->getVA()`

On AArch64, when `src-0x8000000-r_addend <= dst < src-0x8000000`, the condition
`target->inBranchRange(rel.type, src, rel.sym->getVA(rel.addend))` may
incorrectly consider a thunk reusable.
`rel.addend = -getPCBias(rel.type)` resets the addend to 0 for AArch64/PPC
and the zero addend is used by `rel.sym->getVA(rel.addend)` to check
out-of-range relocations.

See the test for a case this computation is wrong:
`error: a.o:(.text_high+0x4): relocation R_AARCH64_JUMP26 out of range: -134217732 is not in [-134217728, 134217727]`
I have seen a real world case with r_addend=19960.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D117734
2022-01-24 09:03:21 -08:00
serge-sans-paille 5f290c090a Move STLFunctionalExtras out of STLExtras
Only using that change in StringRef already decreases the number of
preoprocessed lines from 7837621 to 7776151 for LLVMSupport

Perhaps more interestingly, it shows that many files were relying on the
inclusion of StringRef.h to have the declaration from STLExtras.h. This
patch tries hard to patch relevant part of llvm-project impacted by this
hidden dependency removal.

Potential impact:
- "llvm/ADT/StringRef.h" no longer includes <memory>,
  "llvm/ADT/Optional.h" nor "llvm/ADT/STLExtras.h"

Related Discourse thread:
https://llvm.discourse.group/t/include-what-you-use-include-cleanup/5831
2022-01-24 14:13:21 +01:00
Peter Smith a08447d0de [LLD][ELF][AArch64] Update test with incorrect REQUIRES line [NFC]
D54759 introduced aarch64-combined-dynrel.s and
aarch64-combined-dynrel-ifunc.s . Unfortunately the requires line
at the top was AArch64 instead of aarch64 which means they were never
run. Update the tests to use aarch64 and fix to match current lld output.

Differential Revision: https://reviews.llvm.org/D117896
2022-01-24 10:04:28 +00:00
Sam Clegg ac2f3df839 [lld][WebAssembly] Remove redundant config setting
Unresolved symbols are not currently reported when building with
`-shared` or `-pie` so setting unresolvedSymbols doesn't have any
effect.

Differential Revision: https://reviews.llvm.org/D117737
2022-01-20 15:21:56 -08:00
Roger Kim f84023a812 [lld][macho] Stop grouping symbols by sections in mapfile.
As per [Bug 50689](https://bugs.llvm.org/show_bug.cgi?id=50689),

```
2. getSectionSyms() puts all the symbols into a map of section -> symbols, but this seems unnecessary. This was likely copied from the ELF port, which prints a section header before the list of symbols it contains. But the Mach-O map file doesn't print these headers.
```

This diff removes `getSectionSyms()` and keeps all symbols in a flat vector.

What does ld64's mapfile look like?
```
$ llvm-mc -filetype=obj -triple=x86_64-apple-darwin test.s -o test.o
$ llvm-mc -filetype=obj -triple=x86_64-apple-darwin foo.s -o foo.o
$ ld -map map test.o foo.o -o out -L/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib -lSystem
```

```
[  0] linker synthesized
[  1] test.o
[  2] foo.o
0x100003FB7     0x00000001      __TEXT  __text
0x100003FB8     0x00000000      __TEXT  obj
0x100003FB8     0x00000048      __TEXT  __unwind_info
0x100004000     0x00000001      __DATA  __common
0x100003FB7     0x00000001      [  1] _main
0x100003FB8     0x00000000      [  2] _foo
0x100003FB8     0x00000048      [  0] compact unwind info
0x100004000     0x00000001      [  1] _number
```

Perf numbers when linking chromium framework on a 16-Core Intel Xeon W Mac Pro:
```
base           diff           difference (95% CI)
sys_time   1.406 ± 0.020  1.388 ± 0.019  [  -1.9% ..   -0.6%]
user_time  5.557 ± 0.023  5.914 ± 0.020  [  +6.2% ..   +6.6%]
wall_time  4.455 ± 0.041  4.436 ± 0.035  [  -0.8% ..   -0.0%]
samples    35             35
```

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D114735
2022-01-20 12:16:37 -08:00