Commit Graph

11951 Commits

Author SHA1 Message Date
Reid Kleckner c10f80eb7b [COFF] Update LLD yaml test cases to include .bss size
These yaml test cases appear to have been affected by PR41836

Right now what happens is that these empty .bss sections are merged into
.data, then the .data output section ends up having a zero virtual size,
and it is discarded from the output after addresses are assigned.
However, we've already assigned OutputSections to Chunks, so we don't
correctly report the zero-sized chunks that were in there as having been
discarded. Soon, we will report them as discarded, so these test cases
need to be updated to have a non-zero size so they aren't discarded.

llvm-svn: 360476
2019-05-10 22:12:51 +00:00
Fangrui Song 6150407951 [llvm-objdump] Print st_other
Add support for ".hidden" ".internal" ".protected" and " 0x%02x" for
other st_other bits used by some architectures.

Reviewed By: sfertile

Differential Revision: https://reviews.llvm.org/D61718

llvm-svn: 360439
2019-05-10 16:24:57 +00:00
Fangrui Song 6cdd68e386 [PPC64] Define getThunkSectionSpacing() based on the range of R_PPC64_REL24
Suggested by Sean Fertile and Peter Smith.

Thunk section spacing decrease the total number of thunks. I measured a
decrease of 1% or less in some large programs, with no perceivable
slowdown in link time. Override getThunkSectionSpacing() to enable it.
0x2000000 is the farthest point R_PPC64_REL24 can reach. I tried several
numbers and found 0x2000000 works the best. Numbers near 0x2000000 work
as well but let's just use the simpler number.

As demonstrated by the updated tests, this essentially changes placement
of most thunks to the end of the output section. We leverage this
property to fix PR40740 reported by Alfredo Dal'Ava Júnior:

The output section .init consists of input sections from several object
files (crti.o crtbegin.o crtend.o crtn.o). Sections other than the last
one do not have a terminator. With this patch, we create the thunk after
the last .init input section and thus fix the issue. This is not
foolproof but works quite well for such sections (with no terminator) in
practice.

Reviewed By: ruiu, sfertile

Differential Revision: https://reviews.llvm.org/D61720

llvm-svn: 360405
2019-05-10 05:51:00 +00:00
Sam Clegg ea38ac5ba3 [WebAssembly] Don't assume that strongly defined symbols are DSO-local
The current PIC model for WebAssembly is more like ELF in that it
allows symbol interposition.

This means that more functions end up being addressed via the GOT
and fewer directly added to the wasm table.

One effect is a reduction in the number of wasm table entries similar
to the previous attempt in https://reviews.llvm.org/D61539 which was
reverted.

Differential Revision: https://reviews.llvm.org/D61772

llvm-svn: 360402
2019-05-10 01:52:08 +00:00
Reid Kleckner 4c64256b51 [COFF] Simplify Chunk::writeTo and remove OutputSectionOff, NFC
Summary:
Prior to this change, every implementation of writeTo would add
OutputSectionOff to the output section buffer start before writing data.
Instead, do this math in the caller, so that it can be written once
instead of many times.

The output section offset is always equivalent to the difference between
the chunk RVA and the output section RVA, so we can replace the one
remaining usage of OutputSectionOff with that subtraction.

This doesn't change the size of SectionChunk because of alignment
requirements, but I will rearrange the fields in a follow-up change to
accomplish that.

Reviewers: ruiu, aganea

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61696

llvm-svn: 360376
2019-05-09 21:21:22 +00:00
Sam Clegg 08fa01a9b7 Revert "[WebAssembly] Don't generate unused table entries."
This reverts commit b33fdb7768.

This change apparently broke am emscripten test.

llvm-svn: 360367
2019-05-09 19:34:32 +00:00
Ben Dunbobbin 3edca1ac1a [LLD][NFC] Refactor: BuildID hash size now computed in one place.
Differential Revision: https://reviews.llvm.org/D61078

llvm-svn: 360316
2019-05-09 08:08:09 +00:00
Fangrui Song bd086817f6 [ELF] Initialize Target before it may be dereferenced by findAux when reporting "duplicate symbol" error
for (InputFile *F : Files)
      Symtab->addFile<ELFT>(F); // if there is a duplicate symbol error

    ...

    Target = getTarget();

When parsing .debug_info in the object file (for better diagnostics),
DWARF.cpp findAux may dereference the null pointer Target

    auto *DR = dyn_cast<Defined>(&File->getRelocTargetSym(Rel));
    if (!DR) {
      // Broken debug info may point to a non-defined symbol,
      // some asan object files may also contain R_X86_64_NONE
      RelType Type = Rel.getType(Config->IsMips64EL);
      if (Type != Target->NoneRel) /// Target is null

Move the assignment of Target to an earlier place to fix this.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D61712

llvm-svn: 360305
2019-05-09 01:45:53 +00:00
Bob Haarman f3fb7fac32 [lld-link] initialize targets and asmparsers before invoking lib
Summary:
When using lld-link to build static libraries containing object files
with module assembly, the program would crash with "Assertion `T &&
T->hasMCAsmParser()' failed". This change causes the code in lld-link
that initialized Targets, TargetInfos, and AsmParsers (which already
existed) to be run before entering the lib building path (which needs
it). This avoids the error (and is what llvm-lib and llvm-ar do, too).

Fixes PR41803.

Reviewers: ruiu, rnk, hans

Reviewed By: ruiu

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61699

llvm-svn: 360295
2019-05-08 22:11:02 +00:00
Sam Clegg a1282a39ba [WebAssembly] Handle command line options consistently with the ELF backend.
Differential Revision: https://reviews.llvm.org/D61645

llvm-svn: 360266
2019-05-08 16:20:05 +00:00
Reid Kleckner 34e9c41164 [COFF] Store Chunk RVAs and section offsets as uint32_t
Saves 8 bytes on SectionChunk, one of the most commonly allocated data
structures.

llvm-svn: 360188
2019-05-07 20:30:41 +00:00
Simon Atanasyan 3bdb81c26d [mips] Fix ld instruction in PLT entries on MIPS64
Use `ld` and `daddiu` instructions in MIPS64 PLT records. That fixes a
segmentation fault.

Patch by Qiao Pengcheng.

Differential Revision: https://reviews.llvm.org/D61586

llvm-svn: 360187
2019-05-07 20:26:23 +00:00
Simon Atanasyan 494b763cfc [mips] Rename test case. NFC
This test case checks MIPS PLT records for N64 ABI. For the N32 ABI case
there is a separate test case `mips-plt-n32.s`.

llvm-svn: 360186
2019-05-07 20:26:12 +00:00
Sam Clegg b33fdb7768 [WebAssembly] Don't generate unused table entries.
When generating PIC output only relocations of type
R_WASM_TABLE_INDEX_REL_SLEB should generate table entries.

R_WASM_TABLE_INDEX_I32 get resolved at runtime via the auto-generated
__wasm_apply_relocs functions.

R_WASM_TABLE_INDEX_SLEB are not allowed in PIC code.

Differential Revision: https://reviews.llvm.org/D61539

llvm-svn: 360165
2019-05-07 15:46:30 +00:00
Nico Weber 4b81e9f8d1 lld-link: Allow /? as option prefix, like -? is allowed
link.exe seems to allow `/?foo` and `-?foo` in addition to `/foo` and `-foo`.

Since lld-link already supports the `-?foo` spelling, support `/?foo` as well.

Differential Revision: https://reviews.llvm.org/D61375

llvm-svn: 360150
2019-05-07 14:15:35 +00:00
Nico Weber 54743d5767 Add typo correction for command-line flags to ELF and COFF lld drivers
For lld-link, unknown '/'-style flags are treated as filenames on POSIX
systems, so only '-'-style flags get typo correction for now. This
matches clang-cl.

PR37006.

Differential Revision: https://reviews.llvm.org/D61443

llvm-svn: 360145
2019-05-07 13:48:30 +00:00
George Rimar 72f7a98876 [LLD][ELF] - Remove symbol-name-offset.elf binary from test cases.
It was possible to convert the test case to YAML test.
After that, we have only one binary test left in LLD/ELF.

llvm-svn: 360139
2019-05-07 12:59:44 +00:00
Fangrui Song f3994e4dfa [ELF] Reorder BitcodeFiles.empty() to call thinLTOCreateEmptyIndexFiles() in only one place
It makes the --plugin-opt=obj-path= and --plugin-opt=thinlto-index-only=
behavior more consistent - the files will be created in the
BitcodeFiles.empty() case, but I assume whether it behaves this way is
not required by anyone.

LTOObj->run() cannot run with empty BitcodeFiles. There would be an error:

    ld.lld: error: No available targets are compatible with triple ""

Differential Revision: https://reviews.llvm.org/D61635

llvm-svn: 360129
2019-05-07 10:40:26 +00:00
Fangrui Song 912251e82f [PPC64] toc-indirect to toc-relative relaxation
This is based on D54720 by Sean Fertile.

When accessing a global symbol which is not defined in the translation unit,
compilers will generate instructions that load the address from the toc entry.

If the symbol is defined, non-preemptable, and addressable with a 32-bit
signed offset from the toc pointer, the address can be computed
directly. e.g.

    addis 3, 2, .LC0@toc@ha  # R_PPC64_TOC16_HA
    ld    3, .LC0@toc@l(3)   # R_PPC64_TOC16_LO_DS, load the address from a .toc entry
    ld/lwa 3, 0(3)           # load the value from the address

    .section .toc,"aw",@progbits
    .LC0: .tc var[TC],var

can be relaxed to

    addis 3,2,var@toc@ha     # this may be relaxed to a nop,
    addi  3,3,var@toc@l      # then this becomes addi 3,2,var@toc
    ld/lwa 3, 0(3)           # load the value from the address

We can delete the test ppc64-got-indirect.s as its purpose is covered by
newly added ppc64-toc-relax.s and ppc64-toc-relax-constants.s

Reviewed By: ruiu, sfertile

Differential Revision: https://reviews.llvm.org/D60958

llvm-svn: 360112
2019-05-07 04:26:05 +00:00
Sam Clegg 5f8c2edef3 [WebAssembly] Add more test coverage for reloctions against section symbols
The only known user of this relocation type and symbol type is
the debug info sections, but we were not testing the `--relocatable`
output path.

This change adds a minimal test case to cover relocations against
section symbols includes `--relocatable` output.

Differential Revision: https://reviews.llvm.org/D61623

llvm-svn: 360110
2019-05-07 03:53:16 +00:00
Fangrui Song 12fb52007b [AMDGPU][test] Define local symbols used in amdgpu-relocs.s
Differential Revision: https://reviews.llvm.org/D61594

llvm-svn: 360046
2019-05-06 14:17:59 +00:00
Alexander Kornienko 8b92ec521d [lld] A better version of the fix in r359942.
Thanks to George Rimar for the suggestion.

llvm-svn: 360040
2019-05-06 12:11:30 +00:00
Alexander Kornienko 3f796f974d [lld] Specify output file explicitly
The test shouldn't try to create `a.out` in the current directory, which can be
read-only (and it is in our test setup).

llvm-svn: 359942
2019-05-03 23:11:32 +00:00
Reid Kleckner 0a1b1d6e62 Shrink SectionChunk by combining Relocs and SectionName sizes
SectionChunk is one of the most frequently allocated data structures in
LLD, since there are about four per function when optimizations and
debug info are enabled (.text, .pdata, .xdata, .debug$S).

A PE COFF file cannot be larger than 2GB, so there is an inherent limit
on the length of the section name and the number of relocations.
Decompose the ArrayRef and StringRef into pointer and size, and put them
back together in the accessors for section name and relocation list.

I plan to gather complete performance numbers later by padding
SectionChunk with dead data and measuring performance after all the size
optimizations are done.

llvm-svn: 359923
2019-05-03 20:17:14 +00:00
Fangrui Song d45df09435 [ELF] Place SHT_NOTE sections with the same alignment into one PT_NOTE
Summary:
While the generic ABI requires notes to be 8-byte aligned in ELF64, many
vendor-specific notes (from Linux, NetBSD, Solaris, etc) use 4-byte
alignment.

In a PT_NOTE segment, if 4-byte aligned notes are followed by an 8-byte
aligned note, the possible 4-byte padding may make consumers fail to
parse the 8-byte aligned note. See PR41000 for a recent report about
.note.gnu.property (NT_GNU_PROPERTY_TYPE_0).
(Note, for NT_GNU_PROPERTY_TYPE_0, the consumers should probably migrate
to PT_GNU_PROPERTY, but the alignment issue affects other notes as well.)

To fix the issue, don't mix notes with different alignments in one
PT_NOTE. If compilers emit 4-byte aligned notes before 8-byte aligned
notes, we'll create at most 2 segments.

sh_size%sh_addralign=0 is actually implied by the rule for linking
unrecognized sections (in generic ABI), so we don't have to check that.
Notes that match in name, type and attribute flags are concatenated into
a single output section. The compilers have to ensure
sh_size%sh_addralign=0 to make concatenated notes parsable.

An alternative approach is to create a PT_NOTE for each SHT_NOTE, but
we'll have to incur the sizeof(Elf64_Phdr)=56 overhead every time a new
note section is introduced.

Reviewers: ruiu, jakehehrlich, phosek, jhenderson, pcc, espindola

Subscribers: emaste, arichardson, krytarowski, fedor.sergeev, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61296

llvm-svn: 359853
2019-05-03 00:35:49 +00:00
Nico Weber 81862f82ee lld-link: Add /force:multipleres extension to make dupe resource diag non-fatal
As a side benefit, lld-link now reports more than one duplicate resource
entry before exiting with an error even if the new flag is not passed.

llvm-svn: 359829
2019-05-02 21:21:55 +00:00
Fangrui Song 0178cff279 [ELF] --plugin-opt=thinlto-index-only: create empty index files even if all bitcode files are lazy
Summary:
The gold plugin behavior (creating empty index files for lazy bitcode
files) was added in D46034, but it missed the case when there is no
non-lazy bitcode files, e.g.

    ld.lld -shared crti.o crtbeginS.o --start-lib bitcode.o --end-lib ...

crti.o crtbeginS.o are not bitcode, but our distributed build system
wants bitcode.o.thinlto.bc to confirm all expected outputs are created
based on all of the modules provided to the linker.

Differential Revision: https://reviews.llvm.org/D61420

llvm-svn: 359788
2019-05-02 14:05:20 +00:00
Fangrui Song 8be28cdc52 [Object] Change getSectionName() to return Expected<StringRef>
Summary:
It currently receives an output parameter and returns
std::error_code. Expected<StringRef> fits for this purpose perfectly.

Differential Revision: https://reviews.llvm.org/D61421

llvm-svn: 359774
2019-05-02 10:32:03 +00:00
Fangrui Song d8c2fa99c1 [ELF] Delete a cant-write test from test/lto/thinlto-index-only.ll
The test is performed by thinlto-cant-write-index.ll

llvm-svn: 359769
2019-05-02 09:29:24 +00:00
Nico Weber 413517ecfe lld-link: Make "duplicate resource" error message a bit more concise
Reduces the error message from:
    lld-link: error: failed to parse .res file: duplicate resource: type STRINGTABLE (ID 6)/name ID 3/language 1033, in test1.res and in test2.res

To:
    lld-link: error: duplicate resource: type STRINGTABLE (ID 6)/name ID 3/language 1033, in test1.res and in test2.res

Make sure every error message emitted by cvtres contains the name of at
least one ".res" file, so that removing the "failed to parse .res file"
string doesn't lose information.

Differential Revision: https://reviews.llvm.org/D61388

llvm-svn: 359749
2019-05-02 01:52:24 +00:00
Fangrui Song c669ef1721 Delete trailing \r. NFC
llvm-svn: 359745
2019-05-02 00:39:03 +00:00
Ben Dunbobbin 6e32dd6cfd [LLD] Emit dynamic relocations for references to script symbols in -pie links
https://reviews.llvm.org/D55423 caused LLD to stop emitting dynamic relocations for references to script symbols in -pie links.

This patch fixes that regression.

https://reviews.llvm.org/D61298

llvm-svn: 359683
2019-05-01 14:07:31 +00:00
Fangrui Song 5387c2cd17 [llvm-objdump] Print newlines before and after "Disassembly of section ...:"
This improves readability and the behavior is consistent with GNU objdump.

The new test test/tools/llvm-objdump/X86/disassemble-section-name.s
checks we print newlines before and after "Disassembly of section ...:"

Differential Revision: https://reviews.llvm.org/D61127

llvm-svn: 359668
2019-05-01 10:40:48 +00:00
Fangrui Song 4672e52e22 [llvm-readobj] llvm-readobj --elf-output-style=GNU => llvm-readelf
While updating the test, change -l -S to -S -l as the output of -S goes
before -l.

llvm-svn: 359653
2019-05-01 06:02:16 +00:00
Fangrui Song b159906a9a [test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC
Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t => --symbols
-sd => --section-data

llvm-svn: 359651
2019-05-01 05:49:01 +00:00
Andrew Ng 24896d304d [LLD][ELF] /DISCARD/ output sections should not be orphans
/DISCARD/ output sections were being treated as orphans. As a result, if
a /DISCARD/ output section has been assigned a PHDR, it could cause
incorrect assignment of sections to segments.

Differential Revision: https://reviews.llvm.org/D61186

llvm-svn: 359565
2019-04-30 14:31:22 +00:00
Andrew Ng 0f4c58f6f4 [LLD][ELF] Fix getRankProximity to "ignore" not live sections
This is a follow up to r358979 which made findOrphanPos only consider
live sections. Unfortunately, this required change to getRankProximity,
used by findOrphanPos, was missed.

Differential Revision: https://reviews.llvm.org/D61197

llvm-svn: 359554
2019-04-30 12:27:06 +00:00
Nico Weber 99bad37013 Add more lld release notes
llvm-svn: 359518
2019-04-29 23:26:21 +00:00
Nico Weber aec5dcc457 Add some lld-link 9.0 release notes
llvm-svn: 359412
2019-04-29 00:42:05 +00:00
George Rimar dee900ae59 [LLD][ELF] - Do not remove empty sections referenced in LOADADDR/ADDR commands.
This is https://bugs.llvm.org//show_bug.cgi?id=38750.

If script references empty sections in LOADADDR/ADDR commands

.empty  : { *(.empty ) }
.text   : AT(LOADADDR (.empty) + SIZEOF (.empty)) { *(.text) }
then an empty section will be removed and LOADADDR/ADDR will evaluate to null.
It is not that user may expect from using of the generic script, what is a common case.

Differential revision: https://reviews.llvm.org/D54621

llvm-svn: 359279
2019-04-26 06:59:30 +00:00
Fangrui Song 98b70f6705 [ELF] Change std::max<uint64_t> to uint32_t for section alignment
Summary:
We use `uint32_t SectionBase::Alignment` and `uint32_t
PhdrEntry::p_align` despite alignments being 64 bits in ELF64.
Fix the std::max template arguments accordingly.

The currently 160-byte InputSection will become 168 bytes if we make SectionBase::Alignment uint64_t.

Differential Revision: https://reviews.llvm.org/D61171

llvm-svn: 359268
2019-04-26 04:07:58 +00:00
Sam Clegg b685ddf288 [WebAssembly] Always take into account added when applying runtime relocations
The code we generate for applying data relocations at runtime omitted
the symbols with GOT entries.

Also refactor the code to reduce duplication.

Differential Revision: https://reviews.llvm.org/D61111

llvm-svn: 359207
2019-04-25 17:11:54 +00:00
George Rimar 44f2d74aa5 [LLD][ELF] - Convert symbol-index.s testcase to a YAML test case. NFCI.
This removes one more binary object from the inputs and fixes the
test case description.

Previously it said that:
"symbol-index.elf has incorrect type of .symtab section.
There is no symbol bodies because of that and any symbol index becomes incorrect."

But the real reason of the failture was not the incorrect type of a symbol table,
but invalid index of the symbol used in a relocation, what happened because
previous test tried to read .symtab as a SHT_RELA section.

llvm-svn: 359197
2019-04-25 15:08:52 +00:00
George Rimar e043417268 [LLD][ELF] - Move the test to a correct folder, remove excessive input. NFCI.
This test should live in `invalid` folder.

Also it was possible to avoid adding input
with use of `-docnum=x` yaml2obj argument.

llvm-svn: 359194
2019-04-25 14:53:23 +00:00
Nico Weber c0838af754 lld-link: Implement /swaprun: flag
r191276 added this to old LLD, but it never made it to new LLD -- except
that the flag was in Options.td, so it was silently ignored. I figured
it should be easy to implement, so I did that instead of removing the
flags from Options.td.

I then discovered that link.exe also supports comma-separated lists of
'cd' and 'net', which made the parsing code a bit annoying.

The Alias technique in Options.td is to get nice help output.

Differential Revision: https://reviews.llvm.org/D61067

llvm-svn: 359192
2019-04-25 14:02:26 +00:00
Nico Weber 23cb79ff93 llvm-cvtres: Make new dupe resource error a bit friendlier
For well-known type IDs, include the name of the type.

To not duplicate the ID->name map, make llvm-readobj call this new
function as well.  It has slightly different output, so this also
requires updating a few tests.

Differential Revision: https://reviews.llvm.org/D61086

llvm-svn: 359153
2019-04-24 23:26:30 +00:00
Reid Kleckner 54c8182a3f [COFF] Don't emit .gfids sections when CFG is off
Put them on the list of GuardFidChunks instead of the main Chunks list,
even with CFG is off. It will be ignored if CFG is disabled.

llvm-svn: 359137
2019-04-24 20:38:37 +00:00
Sam Clegg f7f00ebc27 [docs] Copy-edit lld/docs/WebAssembly.rst
Fixes small typos in WebAssembly documentation. I first noticed the
sub-heading "Bahavior", and then decided to review the whole file.

Patch by Christoph Siedentop!

Differential Revision: https://reviews.llvm.org/D60987

llvm-svn: 359103
2019-04-24 15:13:35 +00:00
Fangrui Song 5929553868 [ELF] Delete a redundant SHT_NOBITS -> SHT_PROGBITS after D60131
Differential Revision: https://reviews.llvm.org/D61006

llvm-svn: 359099
2019-04-24 14:44:07 +00:00
Fangrui Song 513d3658e7 [PPC64] Consider localentry offset when computing branch distance
Summary:
We don't take localentry offset into account, and thus may fail to
create a long branch when the gap is just a few bytes smaller than 2^25.

relocation R_PPC64_REL24 out of range: 33554432 is not in [-33554432, 33554431]
relocation R_PPC64_REL24 out of range: 33554436 is not in [-33554432, 33554431]

Fix that by adding the offset to the symbol VA.

Differential Revision: https://reviews.llvm.org/D61058

llvm-svn: 359094
2019-04-24 14:03:30 +00:00