Commit Graph

10911 Commits

Author SHA1 Message Date
Shoaib Meenai 663518d61a [COFF] Unify output section code. NFC
Peter Collingbourne suggested moving the switch to the top of the
function, so that all the code that cares about the output section for a
symbol is in the same place.

Differential Revision: https://reviews.llvm.org/D47497

llvm-svn: 333472
2018-05-29 22:49:56 +00:00
Shoaib Meenai 4e51833611 [COFF] Simplify symbol table output section computation
Rather than using a loop to compare symbol RVAs to the starting RVAs of
sections to determine which section a symbol belongs to, just get the
output section of a symbol directly via its chunk, and bail if the
symbol doesn't have an output section, which avoids having to hardcode
logic for handling dead symbols, CodeView symbols, etc. This was
suggested by Reid Kleckner; thank you.

This also fixes writing out symbol tables in the presence of RVA table
input sections (e.g. .sxdata and .gfids). Such sections aren't written
to the output file directly, so their RVA is 0, and the loop would thus
fail to find an output section for them, resulting in a segfault. Extend
some existing tests to cover this case.

Fixes PR37584.

Differential Revision: https://reviews.llvm.org/D47391

llvm-svn: 333450
2018-05-29 19:07:47 +00:00
Jonas Devlieghere 1fc7fc4db8 [COFF] Update CV register names.
Update tests to use the new prefix for CodeView registers added in
r333421.

llvm-svn: 333425
2018-05-29 14:58:41 +00:00
Sean Fertile ef0f7496d1 [PPC64] Support General-Dynamic tls.
Adds handling of all the relocation types for general-dynamic thread local
storage.

Differential Revision: https://reviews.llvm.org/D47325

llvm-svn: 333420
2018-05-29 14:34:38 +00:00
Simon Atanasyan dc86ba4b8b [ELF][MIPS] Add test case to cover handling of microMIPS relocations in 64-bit mode
llvm-svn: 333418
2018-05-29 14:20:05 +00:00
Rui Ueyama 1fa3c728b9 Fix retpoline PLT for x86-64 when used for >4GB address.
Previously, we wrote only the least significant 32 bits.

llvm-svn: 333313
2018-05-25 21:14:45 +00:00
Rui Ueyama 95d6ca52ac Add a comment for retpoline PLT.
llvm-svn: 333312
2018-05-25 21:02:47 +00:00
Rui Ueyama 7ae70fc14a Fix a bug that we truncated GOTPLT entries to 32 bits.
llvm-svn: 333294
2018-05-25 18:26:14 +00:00
James Henderson 620c4ffdab Add llvm-bcanalyzer as an LLD test dependency
Recently an LLD test change was made that introduced the use of
llvm-bcanalyzer. This change adds the tool to the list of LLD test
dependencies.

Reviewed by: rdhindsa, ruiu

Patch by Owen Reynolds.

llvm-svn: 333277
2018-05-25 14:15:02 +00:00
Sean Fertile 4b25b3e4a6 Fix regex in lld ppc64-ifunc test.
One of the regexes for reading in a hex address was missing the a-f part.

llvm-svn: 333209
2018-05-24 17:07:16 +00:00
Sean Fertile fd69969e54 [PPC64] Set the IRelative relocation type.
Set the IRelative relocation type and extend the related test to verify.
Differential Revision: https://reviews.llvm.org/D46877

llvm-svn: 333203
2018-05-24 16:32:14 +00:00
Zaara Syeda 85197a0842 [PPC64] Add .toc section after .got section
PPC64 maintains a compiler managed got in the .toc section. When accessing a
global variable through got-indirect access, a .toc entry is created for the
variable. The relocation for the got-indirect access will refer to the .toc
section rather than the symbol that is actually accessed. The .toc entry
contains the address of the global variable. We evaluate the offset from
r2 (which is the TOC base) to the address of the toc entry for the global
variable. Currently, the .toc is not near the .got. This causes errors because
the offset from r2 to the toc section is too large. The linker needs to add
all the .toc input sections to the .got output section, merging the compiler
managed got with the linker got. This ensures that the offsets from the TOC
base to the toc entries are not too large.

This patch puts the .toc section right after the .got section.

Differential Revision: https://reviews.llvm.org/D45833

llvm-svn: 333199
2018-05-24 15:59:41 +00:00
Fangrui Song bdbe5d8477 Revert "[ELF] Simplify. NFC"
This reverts commit cc6f052261096dc9d4c9d3123e37b023c3e171df.

llvm-svn: 333099
2018-05-23 16:51:23 +00:00
Nicola Zaghen 5c4fb4566d Replace last DEBUG occurrence with LLVM_DEBUG in lld.
llvm-svn: 333084
2018-05-23 14:03:01 +00:00
Peter Collingbourne 7ab7f149b2 ELF: Do not ICF sections named with a C identifier.
A user program may enumerate sections named with a C identifier using
__start_* and __stop_* symbols. We cannot ICF any such sections because
that could change program semantics.

Differential Revision: https://reviews.llvm.org/D47242

llvm-svn: 333054
2018-05-23 02:14:28 +00:00
Peter Collingbourne 11dc7fcae2 ELF: Do not ICF two sections with different output sections.
Note that this doesn't do the right thing in the case where there is
a linker script. We probably need to move output section assignment
before ICF to get the correct behaviour here.

Differential Revision: https://reviews.llvm.org/D47241

llvm-svn: 333052
2018-05-23 01:58:43 +00:00
Sam Clegg 610ac3bd42 [WebAssembly] Fix crash when relocation synbol is not live
When a symbol is GC'd it can still be references by relocations
in the debug sections, but such symbols are not assigned virtual
addresses.

This change adds a new global data symbol which gets GC'd but
should still appears in the output debug info, albeit with a 0
address.

Fixes 37555

Differential Revision: https://reviews.llvm.org/D47238

llvm-svn: 333047
2018-05-23 01:38:00 +00:00
Peter Collingbourne 52d0abd781 Add missing REQUIRES: x86.
llvm-svn: 333043
2018-05-22 23:30:44 +00:00
Peter Collingbourne 3a9e2ca051 ELF: Allow ICF on .data.rel.ro sections.
Differential Revision: https://reviews.llvm.org/D47234

llvm-svn: 333040
2018-05-22 23:22:35 +00:00
Sam Clegg f377030a95 [WebAssembly] Remove dead code from LEB compression pass.
There are only certain relocation types that can exist in the
wasm code section and they are all LEB types.  Remove the dead
code for handling the other (I32) reloc types.

Differential Revision: https://reviews.llvm.org/D47226

llvm-svn: 333030
2018-05-22 20:52:20 +00:00
Sam Clegg 3ad27e92bc Code cleanup in preparation for adding LTO for wasm. NFC.
- Move some common code into Common/rrorHandler.cpp and
  Common/Strings.h.
- Don't use `fatal` when incompatible bitcode files are
  encountered.
- Rename NameRef variable to just Name

See D47162

Differential Revision: https://reviews.llvm.org/D47206

llvm-svn: 333021
2018-05-22 20:20:25 +00:00
Sam Clegg 65a91288fc [WebAssembly] Fix two bugs in LEB compression: properly calculate function body offset, and write I32 values.
* Gets function size field from right location
* Writes I32 values during compression

Patch by Yury Delendik

Differential Revision: https://reviews.llvm.org/D47204

llvm-svn: 333002
2018-05-22 17:06:55 +00:00
Rui Ueyama f1894fe37e Move code to improve readability. NFC.
llvm-svn: 332995
2018-05-22 16:19:38 +00:00
Rui Ueyama 47055bb197 Simplify. NFC.
We can directly assign to a std::pair without std::tie.

llvm-svn: 332994
2018-05-22 16:16:09 +00:00
Fangrui Song bfd08534b0 [ELF] Simplify. NFC
llvm-svn: 332952
2018-05-22 06:28:00 +00:00
Fangrui Song 8d3fcb45e6 CommandFlags.def -> CommandFlags.inc, leftover after r329840
llvm-svn: 332951
2018-05-22 06:12:23 +00:00
Rui Ueyama 0dd56dcdd4 Handle --plugin-opt= options as alias options.
Previously, we had a loop to iterate over options starting with
`--plugin-opt=` and parse them by hand. But we can make OptTable
do that job for us.

Differential Revision: https://reviews.llvm.org/D47167

llvm-svn: 332935
2018-05-22 02:53:11 +00:00
Rui Ueyama 9867c9e2bf Fix typo.
llvm-svn: 332859
2018-05-21 18:12:46 +00:00
James Henderson 1a7aaf3cd5 [ELF] Update due to API change in .debug_line parsing
See r332845.

Reviewed by: grimar

Differential Revision: https://reviews.llvm.org/D46832

llvm-svn: 332846
2018-05-21 15:31:23 +00:00
Richard Trieu 6ac211667d Fix unused variable warning in non-debug builds.
llvm-svn: 332789
2018-05-19 00:37:23 +00:00
Sam Clegg fb983cda8a [WebAssembly] Add option to remove LEB padding at relocate sites
This change adds the ability for lld to remove LEB padding from
code section. This effectively shrinks the size of the resulting
binary in proportion to the number of code relocations.

Since there will be a performance cost this is currently only active for
-O1 and above. Some toolchains may instead want to perform this
compression as a post linker step (for example running a binary through
binaryen will automatically compress these values).

I imagine we might want to make this the default in the future.

Differential Revision: https://reviews.llvm.org/D46416

llvm-svn: 332783
2018-05-18 23:28:05 +00:00
Peter Collingbourne e3f652973e Support: Simplify endian stream interface. NFCI.
Provide some free functions to reduce verbosity of endian-writing
a single value, and replace the endianness template parameter with
a field.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47032

llvm-svn: 332757
2018-05-18 19:46:24 +00:00
Han Shen 3aede9283c Mitigate relocation overflow [part 2 of 2]
_init_array_start/end are placed at 0 if no ".init_array" presents,
this causes .text relocation against them become more prone to overflow.
This CL sets ".init_array" address to that of ".text" to mitigate the situation.

Review: https://reviews.llvm.org/D46200
llvm-svn: 332688
2018-05-18 03:01:06 +00:00
Zachary Turner c762666e87 Resubmit [pdb] Change /DEBUG:GHASH to emit 8 byte hashes."
This fixes the remaining failing tests, so resubmitting with no
functional change.

llvm-svn: 332676
2018-05-17 22:55:15 +00:00
Zachary Turner 1de9fce151 Revert "[pdb] Change /DEBUG:GHASH to emit 8 byte hashes."
A few tests haven't been properly updated, so reverting while
I have time to investigate proper fixes.

llvm-svn: 332672
2018-05-17 21:49:25 +00:00
Zachary Turner 3c4c8a0937 [pdb] Change /DEBUG:GHASH to emit 8 byte hashes.
Previously we emitted 20-byte SHA1 hashes.  This is overkill
for identifying debug info records, and has the negative side
effect of making object files bigger and links slower.  By
using only the last 8 bytes of a SHA1, we get smaller object
files and ~10% faster links.

This modifies the format of the .debug$H section by adding a new
value for the hash algorithm field, so that the linker will still
work when its object files have an old format.

Differential Revision: https://reviews.llvm.org/D46855

llvm-svn: 332669
2018-05-17 21:22:48 +00:00
Reid Kleckner ef77870857 Fix lld wasm debug info test on Windows (path separator, sigh)
llvm-svn: 332668
2018-05-17 21:10:31 +00:00
Reid Kleckner f40f85868e [codeview] Include record prefix in global type hashing
The prefix includes type kind, which is important to preserve. Two
different type leafs can easily have the same interior record contents
as another type.

We ran into this issue in PR37492 where a bitfield type record collided
with a const modifier record. Their contents were bitwise identical, but
their kinds were different.

llvm-svn: 332664
2018-05-17 20:47:22 +00:00
Rui Ueyama 52d783962f Fix typo in error message.
llvm-svn: 332658
2018-05-17 20:25:35 +00:00
Rui Ueyama b75d19c36c Make ALIGN work with -r in linker scripts
Patch by Mark Kettenis.

Make ALIGN work in linker scripts used with the -r option. This works in
GNU ld (ld.bfd) and is used to generate the "random gap" object for
linking the OpenBSD kernel.

Differential Revision: https://reviews.llvm.org/D46839

llvm-svn: 332656
2018-05-17 20:22:39 +00:00
Rui Ueyama f06d494f46 Improve error message for -thinlto-object-suffix-replace and simplify code.
llvm-svn: 332643
2018-05-17 18:27:12 +00:00
Zachary Turner c8dd6ccc8a [COFF] Add /Brepro and /TIMESTAMP options.
Previously we would always write a hash of the binary into the
PE file, for reproducible builds.  This breaks AppCompat, which
is a feature of Windows that relies on the timestamp in the PE
header being set to a real value (or at the very least, a value
that satisfies certain properties).

To address this, we put the old behavior of writing the hash
behind the /Brepro flag, which mimics MSVC linker behavior.  We
also match MSVC default behavior, which is to write an actual
timestamp to the PE header.  Finally, we add the /TIMESTAMP
option (an lld extension) so that the user can specify the exact
value to be used in case he/she manually constructs a value which
is both reproducible and satisfies AppCompat.

Differential Revision: https://reviews.llvm.org/D46966

llvm-svn: 332613
2018-05-17 15:11:01 +00:00
George Rimar 848405b164 [ELF] - Do not crash when do --gc-sections for non-allocatable metadata sections.
Currently, LLD marks all non-allocatable sections except SHF_REL[A] as Live
when doing GC.

This can be a reason of the crash when SHF_LINK_ORDER sections
are involved, because their parents can be dead.

We should do GC for them correctly. The patch implements it.

Differential revision: https://reviews.llvm.org/D46880

llvm-svn: 332589
2018-05-17 10:00:34 +00:00
Fangrui Song 121078bee7 [ELF] PowerOpen ABI -> Power Architecture 64-bit v2 ABI. NFC
Reviewers: sfertile, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D46904

llvm-svn: 332572
2018-05-17 05:34:29 +00:00
Rumeet Dhindsa d2eb089a0e Add support for ThinLTO plugin option thinlto-object-suffix-replace
Differential Revision: https://reviews.llvm.org/D46608

llvm-svn: 332527
2018-05-16 21:04:08 +00:00
Sam Clegg cfeb646f80 [WebAssembly] Fix R_WEBASSEMBLY_FUNCTION_OFFSET_I32 relocation entries
Fixes: lld: warning: unexpected existing value for R_WEBASSEMBLY_FUNCTION_OFFSET_I32: existing=839 expected=838

The existing solution is trying to erroneously recover correct offset of
the function code from the body (which is not a function segment that
includes its size, locals, and code).

The D46763 is trying to maintain the offset of the function code
allowing properly calculate the new relocation entry.

Patch by Yury Delendik

Differential Revision: https://reviews.llvm.org/D46765

llvm-svn: 332412
2018-05-15 22:27:50 +00:00
Benjamin Kramer 5455038d98 [lld] Make helpers static. NFC.
llvm-svn: 332408
2018-05-15 22:01:54 +00:00
Martin Storsjo 0366155500 [MinGW] Handle the GNU ld option -Map for outputting a linker map
Differential Revision: https://reviews.llvm.org/D46872

llvm-svn: 332398
2018-05-15 21:12:29 +00:00
Han Shen b56030ee9e [lld] Mitigate relocation overflow [part 1 of 2].
This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC
sections. We do this to mitigate the possibility that huge .dynsym and
.dynstr sections placed between ro-data and text sections cause
relocation overflow.

Differential Revision: https://reviews.llvm.org/D45788

llvm-svn: 332374
2018-05-15 17:02:35 +00:00
Fangrui Song c505e06134 Remove \brief commands from doxygen comments.
Summary: This is similar to D46290 D46320.

Reviewers: ruiu, grimar

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D46861

llvm-svn: 332372
2018-05-15 16:40:54 +00:00
Nicola Zaghen e7245b429b [lld] Update uses of DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM

Differential Revision: https://reviews.llvm.org/D44977

llvm-svn: 332351
2018-05-15 13:36:20 +00:00
Peter Smith dbef8cc67c [ELF] Implement --keep-unique option
The --keep-unique <symbol> option is taken from gold. The intention is that
<symbol> will be prevented from being folded by ICF. Although not
specifically mentioned in the documentation <symbol> only matches
global symbols, with a warning if the symbol is not found.

The implementation finds the Section defining <symbol> and removes it from
the set of sections considered for ICF.

Differential Revision: https://reviews.llvm.org/D46755

llvm-svn: 332332
2018-05-15 08:57:21 +00:00
Martin Storsjo b7d50115ba [MinGW] Add a LLD specific option -pdb
This allows producing pdb debug info. This is an LLD specific option
since GCC and GNU binutils doesn't support the PDB file format.

Differential Revision: https://reviews.llvm.org/D46796

llvm-svn: 332327
2018-05-15 06:34:18 +00:00
Sam Clegg 65d6380cd6 [WebAssembly] Allow signautre of entry function to be flexible
Since we a no longer using this function for the wasm start
section we don't actually care what its signature is.

Differential Revision: https://reviews.llvm.org/D46594

llvm-svn: 332308
2018-05-14 23:01:16 +00:00
Sam Clegg 3876d89a1b [WebAssembly] Update to match llvm changes
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D46849

llvm-svn: 332306
2018-05-14 22:42:33 +00:00
Peter Collingbourne 62f7af712c COFF: Allow ICFing sections with different alignments.
The combined section gets the maximum alignment of all sections.

Differential Revision: https://reviews.llvm.org/D46786

llvm-svn: 332273
2018-05-14 18:36:51 +00:00
Zaara Syeda 6b8b868db5 [ELF][PPC64] Fix getRelExpr for R_PPC64_REL64
The relocation R_PPC64_REL64 should return R_PC for getRelExpr since it
computes S + A - P.

Differential Revision: https://reviews.llvm.org/D46766

llvm-svn: 332259
2018-05-14 16:39:45 +00:00
Zaara Syeda c87e16718f [ELF][PPC64] Fix getRelExpr for R_PPC64_REL32
The relocation R_PPC64_REL32 should return R_PC for getRelExpr since it
computes S + A - P.

Differential Revision: https://reviews.llvm.org/D46586

llvm-svn: 332252
2018-05-14 15:26:44 +00:00
George Rimar 8f2b2f4e04 [ELF] - Simplify. NFC.
llvm-svn: 332242
2018-05-14 13:21:09 +00:00
Peter Smith 796fb999b3 [ELF] Do not error for missing version when symbol has local version.
If a symbol with an undefined version in a DSO is not going to be
exported into the dynamic symbol table then do not give an error message
for the missing version. This can happen with the --exclude-libs option
which implicitly gives all symbols in a static library the local version.
This matches the behavior of ld.gold and is exploited by the Bionic
dynamic linker on Arm.

Differential Revision: https://reviews.llvm.org/D43126

llvm-svn: 332224
2018-05-14 10:13:56 +00:00
Peter Collingbourne 107f55005b COFF: ICF a section and its associated sections as a unit.
This is needed to avoid merging two functions with identical
instructions but different xdata. It also reduces binary size by
deduplicating identical pdata sections.

Fixes PR35337.

Differential Revision: https://reviews.llvm.org/D46672

llvm-svn: 332169
2018-05-12 02:12:40 +00:00
Peter Collingbourne d25dfe9bda COFF: Add a flag for disabling string tail merging.
We discovered (crbug.com/838449#c24) that string tail merging can
negatively affect compressed binary size, so provide a flag to turn
it off for users who care more about compressed size than uncompressed
size.

Differential Revision: https://reviews.llvm.org/D46780

llvm-svn: 332149
2018-05-11 22:21:36 +00:00
Rumeet Dhindsa ebb7f5c71a Update input file in test
llvm-svn: 332139
2018-05-11 20:50:27 +00:00
Rumeet Dhindsa 2ef385e150 Update test to not check for output file
Differential Revision: https://reviews.llvm.org/D46771

llvm-svn: 332134
2018-05-11 20:28:45 +00:00
Rumeet Dhindsa 304d0d5560 Splitting thinlto.ll test file and renaming other test files.
Differential Revision: https://reviews.llvm.org/D46731

llvm-svn: 332128
2018-05-11 19:37:08 +00:00
Sean Fertile c12f051112 [PPC64] isRelExpr should return true for the PPC Call Exprs.
Both R_PPC_CALL and R_PPC_CALL_PLT Exprs map to the R_PPC64_REL24 relocation
which has the form Sym + addend - P.

Differential Revision: https://reviews.llvm.org/D46654

llvm-svn: 332127
2018-05-11 19:31:19 +00:00
Martin Storsjo 5fb6437012 [MachO] Don't write test files to /tmp, remove them afterwards.
This matches what is done in MachONormalizedFileBinaryWriterTests.cpp
already.

Differential Revision: https://reviews.llvm.org/D46743

llvm-svn: 332114
2018-05-11 18:19:02 +00:00
George Rimar 4c9ae67bb7 [ELF] - Revert of: r332038, r332054, r332060, r332061, r332062, r332063
This reverts "Mitigate relocation overflow [part 1 of 2]." and the following commits which
were trying to fix the bots.

At the moment of r332082, bots are still failing and we need to find the reason of test case breakages first of all.
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/17042/steps/test/logs/stdio
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/29845/steps/test/logs/stdio

llvm-svn: 332085
2018-05-11 08:11:25 +00:00
Fangrui Song a119322c1d [ELF] Fix test
llvm-svn: 332063
2018-05-10 23:57:38 +00:00
Fangrui Song fa0700a978 [ELF] Fix tests after rL332038
llvm-svn: 332062
2018-05-10 23:55:41 +00:00
Fangrui Song c638db5913 [ELF] --warn-backref: don't report backref to weak symbols.
Summary:
Suppose we visit symbols in this order:

1. weak definition of foo in a lazy object
2. reference of foo
3 (optional). definition of foo

bfd/gold allows 123 but not 12.

Current --warn-backrefs implementation will report both cases as a backward reference. With this change, both 123 (intended) and 12 (unintended) are allowed. The usage of weak definitions usually imply there are also global definitions, so the trade-off is justified.

Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D46624

llvm-svn: 332061
2018-05-10 23:53:05 +00:00
Fangrui Song f6f7e0940a [ELF] Fix two tests after D45788
llvm-svn: 332060
2018-05-10 23:51:37 +00:00
Peter Collingbourne b6c5a3045b COFF: Allow ICF on vtable sections.
Differential Revision: https://reviews.llvm.org/D46734

llvm-svn: 332059
2018-05-10 23:31:58 +00:00
Han Shen b3f2172ce4 Fix test cases failure caused by revision 332038.
The previous CL changes the order of output sections, which causes address changes in test cases.

Review: https://reviews.llvm.org/D46730
llvm-svn: 332054
2018-05-10 22:32:39 +00:00
Han Shen 6c0881c3cd Mitigate relocation overflow [part 1 of 2].
This CL is to mitigate R_X86_64_PC32 relocation overflow problems for huge binaries that has near 4G allocated sections.

By examining those binaries, there're 2 issues contributes to the problem:
1). huge ".dynsym" and ".dynstr" stands in the way between .rodata and .text
2). _init_array_start/end are placed at 0 if no ".init_array" presents, this causes .text relocation against them become more prone to overflow.

This CL addresses 1st problem (the 2nd will be addressed in another CL.) by assigning a smaller sortrank to .dynsym and .dynstr thus they no longer stand in between.

llvm-svn: 332038
2018-05-10 20:44:42 +00:00
Peter Collingbourne e28faed768 COFF: Don't create unnecessary thunks.
A thunk is only needed if a relocation points to the undecorated
import name.

Differential Revision: https://reviews.llvm.org/D46673

llvm-svn: 332019
2018-05-10 19:01:28 +00:00
Sam Clegg 668447677a [WebAssembly] Add a flag to control merging data segments
Merging data segments produces smaller code sizes because each segment
has some boilerplate. Therefore, merging data segments is generally the
right approach, especially with wasm where binaries are typically
delivered over the network.

However, when analyzing wasm binaries, it can be helpful to get a
conservative picture of which functions are using which data
segments[0]. Perhaps there is a large data segment that you didn't
expect to be included in the wasm, introduced by some library you're
using, and you'd like to know which library it was. In this scenario,
merging data segments only makes the analysis worse.

Alternatively, perhaps you will remove some dead functions by-hand[1]
that can't be statically proven dead by the compiler or lld, and
removing these functions might make some data garbage collect-able, and
you'd like to run `--gc-sections` again so that this now-unused data can
be collected. If the segments were originally merged, then a single use
of the merged data segment will entrench all of the data.

[0] https://github.com/rustwasm/twiggy
[1] https://github.com/fitzgen/wasm-snip

Patch by Nick Fitzgerald!

Differential Revision: https://reviews.llvm.org/D46417

llvm-svn: 332013
2018-05-10 18:23:51 +00:00
Nico Weber cac2b3349e lld-link: Add --color-diagnostics(={always,never,auto})?, --no-color-diagnostics flags.
This is most useful when using lld-link on a non-Win host (but it might become
useful on Windows too if lld also grows a fansi-escape-codes flag).

Also make the help for --color-diagnostic mention the valid values in ELF and
wasm, and print the flag name with two dashes in diags, since the one-dash form
is seen as a list of many one-letter flags in some contexts.

https://reviews.llvm.org/D46693

llvm-svn: 332012
2018-05-10 18:19:02 +00:00
Sam Clegg d6beb320b4 [WebAssembly] Simplify writing of exports section. NFC.
Differential Revision: https://reviews.llvm.org/D43963

llvm-svn: 332011
2018-05-10 18:10:34 +00:00
Sam Clegg 262e09018b [WebAssembly] Remove final -wasm component of target triple. NFC.
This has been the default for a while now.

llvm-svn: 332009
2018-05-10 17:59:41 +00:00
Simon Atanasyan d9802236d5 [ELF][MIPS] Add test case to check some microMIPS R6 relocations. NFC
llvm-svn: 331995
2018-05-10 15:56:27 +00:00
Simon Atanasyan dd995bd790 [ELF][MIPS] Add test case to check N32 ABI PLT generation. NFC
llvm-svn: 331994
2018-05-10 15:56:22 +00:00
George Rimar 6b3801824c [ELF] - Improve the test cases for notes sections.
A minor clean up and improvement for our tests for notes sections.

Differential revision: https://reviews.llvm.org/D46690

llvm-svn: 331980
2018-05-10 13:45:34 +00:00
Ed Maste 6556aa6848 [ELF] Omit PT_NOTE for SHT_NOTE without SHF_ALLOC
A non-alloc note section should not have a PT_NOTE program header.

Found while linking ghc (Haskell compiler) with lld on FreeBSD.
ghc emits a .debug-ghc-link-info note section (as the name suggests, it
contains link information) as a SHT_NOTE section without SHF_ALLOC set.

For this case ld.bfd does not emit a PT_NOTE segment for the
.debug-ghc-link-info section.  lld previously emitted a PT_NOTE with
p_vaddr = 0 and FreeBSD's rtld segfaulted when trying to parse a note at
address 0.

llvm.org/pr37361

Differential Revision:	https://reviews.llvm.org/D46623

llvm-svn: 331973
2018-05-10 11:12:18 +00:00
James Henderson d621037788 [ELF] Rework debug line parsing to use llvm::Error and callbacks (LLD-side)
Reviewed by: ruiu, grimar, espindola

Differential Revision: https://reviews.llvm.org/D44562

Summary:
r331971 changes the debug line parser interface to report LLVM errors in an
interface that different executables can use, rather than always being printed
directly as warnings to stderr. This change allows LLD to make use of the new
interface and call its own warning methods to report problems.

llvm-svn: 331972
2018-05-10 10:52:21 +00:00
Martin Storsjo 5c84d442f5 [COFF] Fix dangling StringRefs from SVN 331900
llvm-svn: 331912
2018-05-09 19:07:10 +00:00
Martin Storsjo 0ca06f7950 [COFF] Allow specifying export forwarding in a def file
Previously this was only supported when specified on the command line
or in directives.

Differential Revision: https://reviews.llvm.org/D46244

llvm-svn: 331900
2018-05-09 18:19:41 +00:00
Benjamin Kramer 9a85470a57 [wasm] Update test for variables->retainedNodes rename.
This fixes the test after LLVM r331841.

llvm-svn: 331862
2018-05-09 10:09:23 +00:00
Martin Storsjo 97379ff6b2 [COFF] Improve correctness of def parsing for GNU features
The operator == used for exporting a function with a different
name in the DLL compared to the name in the import library
(which is useful for adding linker level aliases for function
in the import library) is a feature distinct and different from
the operator = used for exporting a function with a different
name (both in import library and DLL) than in the implementation
producing the DLL.

When creating an import library using dlltool, from a def file that
contains forwards (Func = OtherDll.Func), this shouldn't affect the
produced import library, which should still behave just as if it
was a normal exported function.

This clears a lot of confusion and subtle misunderstandings, and
avoids a parameter that was used to avoid creating weak aliases
when invoked from lld. (This parameter was added previously due to
the existing conflation of the two features.)

Differential Revision: https://reviews.llvm.org/D46245

llvm-svn: 331860
2018-05-09 09:22:03 +00:00
Simon Atanasyan d62b3e8f5d [ELF][MIPS] Add test case to cover LA25 r6 thunks generation. NFC
llvm-svn: 331851
2018-05-09 06:51:58 +00:00
Sean Fertile 49914cc807 [PPC64] Add lazy symbol resolution stubs.
Adds support for .glink resolver stubs from the example implementation in the V2
ABI (Section 4.2.5.3. Procedure Linkage Table). The stubs are written to the
PltSection, and the sections are renamed to match the PPC64 ABI:
    .got.plt --> .plt    Type = SHT_NOBITS
    .plt     --> .glink

And adds the DT_PPC64_GLINK dynamic tag to the dynamic section when the plt is
not empty.

Differential Revision: https://reviews.llvm.org/D45642

llvm-svn: 331840
2018-05-09 02:07:53 +00:00
Sriraman Tallam 8244c9c489 Fix test by adding -triple=x86_64-unknown-linux
llvm-svn: 331828
2018-05-09 00:20:45 +00:00
Sriraman Tallam be01d2e3de New option -z keep-text-section-prefix to keep text sections with prefixes separate.
Separate output sections for selected text section prefixes to enable TLB optimizations and for readablilty.

Differential Revision: https://reviews.llvm.org/D45841

llvm-svn: 331823
2018-05-08 23:19:50 +00:00
Rumeet Dhindsa b5b7d6e19c Add support for LTO plugin option obj-path
Differential Revision: https://reviews.llvm.org/D46598

llvm-svn: 331817
2018-05-08 22:37:57 +00:00
Rumeet Dhindsa 1888326b2d Update ThinLTO Indexing logic
Instead of writing empty index for file, this patch tracks the state of files in ObjectToIndexFileState. If the files are not indexed , only then we emit the empty files

Differential Revision: https://reviews.llvm.org/D46480

llvm-svn: 331803
2018-05-08 20:12:07 +00:00
Rui Ueyama d31b54b3c1 Refactor BitcodeCompiler::add(). NFC.
This change makes it explicit that the main loop iterates over a
parallel array, Syms and ObjSyms.

llvm-svn: 331780
2018-05-08 17:50:54 +00:00
Rui Ueyama 2f9fa42892 Fix a bug that a copy of a large vector was created. NFC.
llvm-svn: 331779
2018-05-08 17:50:43 +00:00
Simon Atanasyan 610e621c99 [ELF][MIPS] Fix test case in attempt to restore Windows build-bot. NFC
llvm-svn: 331774
2018-05-08 16:11:40 +00:00
Simon Atanasyan 0560050668 [ELF][MIPS] Fix calculation of GP relative relocations in case of relocatable output
Some MIPS relocations depend on "gp" value. By default, this value has
0x7ff0 offset from a .got section. But relocatable files produced by a
compiler or a linker might redefine this default value and we have to
use it for a calculation of the relocation result. When we generate EXE
or DSO it's trivial. Generating a relocatable output is more difficult
case because the linker does calculate relocations in this case and
cannot store individual "gp" values used by each input object file.
As a workaround we add the "gp" value to the relocation addend.

This fixes https://llvm.org/pr31149

Differential revision: https://reviews.llvm.org/D45972

llvm-svn: 331772
2018-05-08 15:34:06 +00:00
Peter Smith 24d906630b [LLD][ELF][AArch64] Increase test coverage of AArch64ErrataFix [NFC]
In the recognise test convert some ST1 multiple structure to ST1 single
structure to test the isST1SingleOpcode() function.

Differential Revision: https://reviews.llvm.org/D46263

llvm-svn: 331752
2018-05-08 09:36:24 +00:00
Peter Smith f6ed9dd41d [LLD][ELF] Add test cases to improve code coverage of Thunks [NFC]
Add two test cases to improve the code coverage of ThunkSection creation
when there are no existing ThunkSections in range. There are two test
cases, one where a new section can be created and another to trigger the
"InputSection too large for range extension thunk" error message. A recent
code coverage report showed that this section of code wasn't covered by a
test case.

Differential Revision: https://reviews.llvm.org/D46261

llvm-svn: 331751
2018-05-08 09:26:06 +00:00
Fangrui Song 95851515d7 Add a CIE with length 0 unconditionally.
Summary: This is not technically required, but glibc unwind-dw2-fde.c classify_object_over_fdes expects there is a CIE record length 0 as a terminator.

Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D46566

llvm-svn: 331708
2018-05-08 01:19:16 +00:00
Rui Ueyama cdf8d06426 Rename a local variable whose scope is very narrow. NFC.
llvm-svn: 331703
2018-05-07 23:43:48 +00:00
Rui Ueyama ac403ef7f0 Improve error message for --plugin-opt=thinlto-prefix-replace.
llvm-svn: 331700
2018-05-07 23:24:25 +00:00
Rui Ueyama d432f216d1 Rename Config::ThinLTOIndexOnlyObjectFiles -> Config::ThinLTOIndexOnlyArg.
llvm-svn: 331699
2018-05-07 23:24:16 +00:00
Rui Ueyama 397dffd81b Split BitcodeCompiler::init() into two functions. NFC.
Previously, code to initialize Backend and code to initialize Conf are
intermingled in init(), though they don't depend on each other.

Differential Revision: https://reviews.llvm.org/D46554

llvm-svn: 331698
2018-05-07 23:24:07 +00:00
Rumeet Dhindsa 4fb5119215 Add support for thinlto option ( thinlto-emit-imports-files) to emit import files for thinlink.
Differential Revision: https://reviews.llvm.org/D46400

llvm-svn: 331696
2018-05-07 23:14:12 +00:00
Rui Ueyama 554adb2e97 Do not call exit() directly from lld.
Our promise is that as long as there's no fatal error (i.e. broken
file is given to the linker), our main function returns to the caller.
So we can't use exit() in the regular code path.

Differential Revision: https://reviews.llvm.org/D46442

llvm-svn: 331690
2018-05-07 22:11:34 +00:00
Rui Ueyama d54f1c2fed Refactor ThinLTO-related code in BitcodeCompiler.cpp. NFC.
Summary: Refactor ThinLTO-related code in BitcodeCompiler.cpp. NFC.

Reviewers: rdhindsa, espindola

Subscribers: emaste, inglorion, arichardson, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D46549

llvm-svn: 331689
2018-05-07 22:11:24 +00:00
Rumeet Dhindsa d48f236a7e Add test to ensure lld writes linked files to linked objects file for ThinLTO Indexing Only option.
Differential Revision: https://reviews.llvm.org/D46542

llvm-svn: 331671
2018-05-07 20:28:02 +00:00
Rui Ueyama f64f345e1b Do not pass Config members to simplify function signature. NFC.
llvm-svn: 331658
2018-05-07 17:59:52 +00:00
Rui Ueyama 4454b3d1eb Parse --thinlto-prefix-replace early so that we don't need to parse it later. NFC.
llvm-svn: 331657
2018-05-07 17:59:43 +00:00
Rui Ueyama e4ba06eda6 Use StringRef instead of `const std::string &`. NFC.
llvm-svn: 331656
2018-05-07 17:59:34 +00:00
Rui Ueyama 66a9f257b6 Refactor BitcodeCompiler::createLTO. NFC.
llvm-svn: 331655
2018-05-07 17:46:28 +00:00
Roman Lebedev 7cb6896732 ELF Thunks: fix build error: missing 'overrides'
llvm-svn: 331608
2018-05-06 19:50:04 +00:00
Sean Fertile d2e887d2f6 [PPC64] Emit plt call stubs to the text section rather then the plt section.
On PowerPC calls to functions through the plt must be done through a call stub
that is responsible for:
1) Saving the toc pointer to the stack.
2) Loading the target functions address from the plt into both r12 and the
   count register.
3) Indirectly branching to the target function.

Previously we have been emitting these call stubs to the .plt section, however
the .plt section should be reserved for the lazy symbol resolution stubs. This
patch moves the call stubs to the text section by moving the implementation from
writePlt to the thunk framework.

Differential Revision: https://reviews.llvm.org/D46204

llvm-svn: 331607
2018-05-06 19:13:29 +00:00
Andrea Di Biagio 25c1a2f0d1 Fix -Wunused-variable warning introduced at r331566.
llvm-svn: 331589
2018-05-05 10:53:31 +00:00
Sam Clegg 752494bfe3 [WebAssembly] Check function signatures by default
But only produce a warning (for now) unless --fatal-warnings
is passed.

Differential Revision: https://reviews.llvm.org/D46484

llvm-svn: 331574
2018-05-05 01:23:07 +00:00
Sam Clegg 60609c9f12 Add llvm-dwarfdump tool_patterns
Differential Revision: https://reviews.llvm.org/D46481

llvm-svn: 331572
2018-05-05 00:32:26 +00:00
Sam Clegg c1953144ac [WebAssembly] Only perform sanity checking of relocation targets in debug builds
Also:
- Reduce the error to a warning so that debug and release
  versions can still link the same inputs.
- Add another check to verify the input LEB is padded to 5 bytes

Differential Revision: https://reviews.llvm.org/D46479

llvm-svn: 331571
2018-05-05 00:18:43 +00:00
Sam Clegg d177ab2a5f [WebAssembly] Add support for debug (DWARF) sections
Specifically add support for custom sections that contain
relocations, and for the two new relocation types needed
by DWARF sections.

See: https://reviews.llvm.org/D44184

Patch by Yury Delendik!

Differential Revision: https://reviews.llvm.org/D44184

llvm-svn: 331566
2018-05-04 23:14:42 +00:00
Simon Atanasyan b6211d9084 [ELF][MIPS] Reorganize isMipsPIC routine. NFC
llvm-svn: 331555
2018-05-04 20:48:53 +00:00
Simon Atanasyan 86a1219d30 [ELF][MIPS] Add STO_MIPS_MICROMIPS flag to symbols point to microMIPS PLT records
llvm-svn: 331554
2018-05-04 20:48:47 +00:00
Peter Collingbourne e5ad31d376 Object: The default alignment of a section without alignment flags is 16.
Differential Revision: https://reviews.llvm.org/D46420

llvm-svn: 331538
2018-05-04 16:45:57 +00:00
Zaara Syeda edc7a8c1e5 [PPC64] Remove support for ELF V1 ABI in LLD - buildbot fix
Fix buildbot error, failure to build with msvc due to error C2446
Use switch instead of ternary operator.

Differential Revision: https://reviews.llvm.org/D46316

llvm-svn: 331534
2018-05-04 16:04:04 +00:00
Zaara Syeda f61b0733a8 [PPC64] Remove support for ELF V1 ABI in LLD
The current support for V1 ABI in LLD is incomplete.
This patch removes V1 ABI support and changes the default behavior to V2 ABI,
issuing an error when using the V1 ABI. It also updates the testcases to V2
and removes any V1 specific tests.

Differential Revision: https://reviews.llvm.org/D46316

llvm-svn: 331529
2018-05-04 15:09:49 +00:00
Peter Smith 2689d9f4f0 [ELF][AArch64] Add aarch64_elf64_le_vec emulation
Android AOSP has started specifying -m aarch64_elf64_le_vec as supported
by gold and BFD. This is a simple change to add the emulation so that LLD
doesn't immediately error when used as a linker in an AOSP build.

Differential Revision: https://reviews.llvm.org/D46429

llvm-svn: 331521
2018-05-04 14:28:29 +00:00
Peter Smith 9c116180a4 [ELF][AArch64] Add REQUIRES aarch64 to test [NFC]
Forgot to add REQUIRES aarch64 to the test I recently added for D46255.

llvm-svn: 331513
2018-05-04 09:10:18 +00:00
Peter Smith e72d3d32bb [ELF][AArch64] Implement the AArch64 TLSLD_LDST_LO12 family of relocs
Implement the following relocations for AArch64:
R_AARCH64_TLSLE_LDST8_TPREL_LO12_NC
R_AARCH64_TLSLE_LDST16_TPREL_LO12_NC
R_AARCH64_TLSLE_LDST32_TPREL_LO12_NC
R_AARCH64_TLSLE_LDST64_TPREL_LO12_NC
R_AARCH64_TLSLE_LDST128_TPREL_LO12_NC

These are specified in ELF for the 64-bit Arm Architecture.

Fixes pr36727

Differential Revision: https://reviews.llvm.org/D46255

llvm-svn: 331511
2018-05-04 08:53:34 +00:00
Martin Storsjo cc80776eff [COFF] Implement the remaining ARM64 relocations
Now only IMAGE_REL_ARM64_ABSOLUTE and IMAGE_REL_ARM64_TOKEN
are unhandled.

Also add range checks for the existing BRANCH26 relocation.

Differential Revision: https://reviews.llvm.org/D46354

llvm-svn: 331505
2018-05-04 06:06:27 +00:00
Rumeet Dhindsa 9c2af27f80 Added ThinLTO test to verify that index files are not generated if thinlto-index-only is not enabled.
Differential Revision: https://reviews.llvm.org/D46405

llvm-svn: 331478
2018-05-03 20:13:38 +00:00
Simon Atanasyan bc4da23133 [ELF][MIPS] Check that a section has a valid reference to a file in the isMipsPIC routine
llvm-svn: 331470
2018-05-03 17:33:10 +00:00
Sam Clegg a0f095ebd7 [WebAssembly] Add --stack-first option which places the shadow stack at start of linear memory
Fixes https://bugs.llvm.org/show_bug.cgi?id=37181

Differential Revision: https://reviews.llvm.org/D46141

llvm-svn: 331467
2018-05-03 17:21:53 +00:00
Peter Smith 2e54353b86 [LLD][AArch64] Simplify relocations sharing same encoding [NFC]
The code to encode the result in relocateOne for the relocations:
R_AARCH64_LD64_GOT_LO12_NC
R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC
R_AARCH64_TLSDESC_LD64_LO12

is equivalent to that for R_AARCH64_LDST64_ABS_LO12_NC. This is described
in the ABI as "Set the LD/ST immediate field bits [11:3] of X. No overflow
check; check that X&7 =0.
    
Differential Revision: https://reviews.llvm.org/D46247

llvm-svn: 331452
2018-05-03 12:59:52 +00:00
David Zarzycki f161de4e7d [CMake] Fix BUILD_SHARED_LIBS regression due to r331405
llvm-svn: 331444
2018-05-03 10:03:45 +00:00
Rumeet Dhindsa 437f66d06d Update Error Message
https://reviews.llvm.org/D46375

llvm-svn: 331426
2018-05-03 01:54:14 +00:00
Rumeet Dhindsa b082a8790c Updated ThinLTO test to not include forward or backward slash for testing
Differential Revision: https://reviews.llvm.org/D46372

llvm-svn: 331419
2018-05-03 00:28:51 +00:00
Rumeet Dhindsa d366e36bbf Added support for ThinLTO plugin options : thinlto-index-only and thinlto-prefix-replace
Differential Revision: https://reviews.llvm.org/D46034

llvm-svn: 331405
2018-05-02 21:40:07 +00:00
Zaara Syeda 116c0424da Fix warning: result of 32-bit shift implicitly converted to 64 bits - NFC
Fix warning caused by rL331046.

Differential Revision: https://reviews.llvm.org/D45729

llvm-svn: 331181
2018-04-30 14:37:28 +00:00
Ed Maste 59c4962c1d Add -warn-backrefs (r329636) to lld's man page
llvm-svn: 331133
2018-04-29 02:18:48 +00:00
Fangrui Song 8c07d06da9 Migrate from std::pointer_to_unary_function as it is removed in C++17
llvm-svn: 331097
2018-04-28 00:12:02 +00:00
Rafael Espindola bd4d2acb11 Don't create a temporary DenseMap for each input .eh_frame.
These maps are small, but we are creating an destroying one for each
input .eh_frame.

This patch reduces the total memory allocation from 765.54MB to
749.19MB. The peak is still the same: 563.7MB.

llvm-svn: 331075
2018-04-27 20:19:28 +00:00
Rafael Espindola f1652d4c60 Split .eh_frame sections in parellel.
We can now split them in the same spot we split merge sections.

llvm-svn: 331064
2018-04-27 18:17:36 +00:00
Rafael Espindola 9bf1006278 Split merge sections early.
Now that getSectionPiece is fast (uses a hash) it is probably OK to
split merge sections early.

The reason I want to do this is to split eh_frame sections in the same
place.

This does mean that we have to decompress early. Given that the only
compressed sections are debug info, I don't think we are missing much.

It is a small improvement: 0.5% on the geometric mean.

llvm-svn: 331058
2018-04-27 16:29:57 +00:00
Zaara Syeda 82dd99e08e [PPC64] Add offset to local entry point when calling functions without plt
PPC64 V2 ABI describes two entry points to a function. The global entry point
sets up the TOC base pointer. When calling a local function, the call should
branch to the local entry point rather than the global entry point.
Section 3.4.1 describes using the 3 most significant bits of the st_other
field to find out how many instructions there are between the local and global
entry point. This patch adds the correct offset required to branch to the local
entry point of a function.

Differential Revision: https://reviews.llvm.org/D45729

llvm-svn: 331046
2018-04-27 15:41:19 +00:00
Rui Ueyama 50bf643cfb Do not set RequiresNullTerminator. NFC.
When reading object files, we don't need '\0' at end of each file.

llvm-svn: 331045
2018-04-27 15:32:04 +00:00
Fangrui Song 1f3e2b2966 [ELF] Fix typo. NFC
llvm-svn: 331018
2018-04-27 05:50:40 +00:00
Shoaib Meenai 1b1f97ac60 [ELF] Clarify help wording for --symbol-ordering-file
The input file for this option should contain a list of symbols, not a
list of sections, so explicitly refer to ordering symbols (but keep the
reference to laying out sections, since that's how the option must
operate). Referring to the file itself as the "symbol ordering file" is
consistent with --warn-symbol-ordering and less ambiguous than "symbol
file" (albeit slightly redundant).

Differential Revision: https://reviews.llvm.org/D46099

llvm-svn: 331000
2018-04-26 22:25:04 +00:00
Roman Lebedev d338222a8c [LLD][WASM] Handle WASM_SYMBOL_TYPE_SECTION in toString().
Fixes build. If this is not the desired solution, please revert.
WasmSymbolType was changed in rL330982 / D44184

llvm-svn: 330984
2018-04-26 20:00:11 +00:00
Rafael Espindola 40f46bc3e6 Delete unused variable.
llvm-svn: 330978
2018-04-26 19:21:07 +00:00
Sam Clegg 2b8b179867 [WebAssembly] Add version to linking section (to match llvm-side change)
Differential Revision: https://reviews.llvm.org/D46070

llvm-svn: 330971
2018-04-26 18:17:21 +00:00
Rafael Espindola ab44b923f5 Add a comment. NFC.
llvm-svn: 330967
2018-04-26 18:03:04 +00:00
Rafael Espindola ab0cce5f1f Replace SharedSymbols with Defined when creating copy relocations.
This is slightly simpler to read IMHO. Now if a symbol has a position
in the file, it is Defined.

The main motivation is that with this a SharedSymbol doesn't need a
section, which reduces the size of SymbolUnion.

With this the peak allocation when linking chromium goes from 568.1 to
564.2 MB.

llvm-svn: 330966
2018-04-26 17:58:58 +00:00
Rafael Espindola 06cb7c8773 Simplify processRelocAux.
It returns a different Expr only in the case of creating a function
symbol pointing to its plt entry. We can just add a call to
addPltEntry to avoid that and return void.

With this patch further simplifications of how we handle copy
relocations are possible.

llvm-svn: 330960
2018-04-26 17:22:44 +00:00
Rafael Espindola f4a9d56a9a Delete GotPltIndex.
It was always an offset of PltIndex.

This doesn't reduce the size of the structures, but makes it easier to
do so in a followup patch.

llvm-svn: 330953
2018-04-26 16:09:30 +00:00
Rafael Espindola faa3b8a554 Add a test. NFC.
This would have fund a bug in a patch I am working on.

llvm-svn: 330925
2018-04-26 06:10:18 +00:00
Rui Ueyama b774c3c0e5 Simplify. NFC.
llvm-svn: 330892
2018-04-26 01:38:29 +00:00
Bob Haarman 947647d0c1 [COFF] more informative "broken object file" diagnostics
Summary:
When a symbol refers to a special section or a section that doesn't
exist, lld would fatal with "broken object file". This change gives a
different message for each scenario, and includes the name of the
file, name of the symbol, and the section being referred to.

Reviewers: pcc, ruiu

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46090

llvm-svn: 330883
2018-04-25 23:33:19 +00:00
Rui Ueyama 5fcebff485 Remove unused features from StringRefZ and move it to Symbols.h.
Differential Revision: https://reviews.llvm.org/D46087

llvm-svn: 330879
2018-04-25 22:34:21 +00:00
Rafael Espindola 1eeb26293d Pack symbols a bit more.
Before this patch:

Symbol 56
Defined 80
Undefined 56
SharedSymbol 88
LazyArchive 72
LazyObject 56

With this patch

Symbol 48
Defined 72
Undefined 48
SharedSymbol 80
LazyArchive 64
LazyObject 48

The result is that peak allocation when linking chromium (according to
heaptrack) goes from 578 to 568 MB.

llvm-svn: 330874
2018-04-25 21:44:37 +00:00
Rafael Espindola 047f857642 Also demote lazy symbols.
This is not a big simplification right now, but the special cases for
lazy symbols have been a common source of bugs in the past.

llvm-svn: 330869
2018-04-25 20:46:08 +00:00
Hans Wennborg 03ca8f4fd0 [COFF] Don't set the tsaware bit on DLLs
It doesn't apply to DLLs, and link.exe doesn't set it.

Differential Revision: https://reviews.llvm.org/D46077

llvm-svn: 330868
2018-04-25 20:32:00 +00:00
George Rimar d30a78b3fe [ELF] - Eliminate the AssertCommand.
Currently, LLD supports ASSERT as a separate command.

We support two forms now.

Assign expression-form: . = ASSERT(0x100)
(old GNU ld required it and some scripts in the wild are still using
something like . = ASSERT((_end - _text <= (512 * 1024 * 1024)), "kernel image bigger than KERNEL_IMAGE_SIZE");

Nowadays above is not a mandatory form and command-like form is commonly used:
ASSERT(<expr>, "text);

The return value of the ASSERT is Dot. That was implemented in D30171.
It looks like (2) is just a short version of (1) then.

GNU ld does *not* list ASSERT as a SECTIONS command:
https://sourceware.org/binutils/docs/ld/SECTIONS.html#SECTIONS

Given above we probably can change ASSERT to be an assignment to Dot. 
That makes the rest of the code much simpler. Patch do that.

Differential revision: https://reviews.llvm.org/D45434

llvm-svn: 330814
2018-04-25 11:16:31 +00:00
Rafael Espindola 61376d9bed Bring r329960 back.
The fix is to copy Used when replacing the symbol.

Original message:

Do not keep shared symbols created from garbage-collected eliminated DSOs.

If all references to a DSO happen to be weak, and if the DSO is
specified with --as-needed, the DSO is not added to DT_NEEDED.
If that happens, we also need to eliminate shared symbols created
from the DSO. Otherwise, they become dangling references that point
to non-exsitent DSO.

Fixes https://bugs.llvm.org/show_bug.cgi?id=36991

Differential Revision: https://reviews.llvm.org/D45536

llvm-svn: 330788
2018-04-25 00:29:13 +00:00
Bob Haarman 8832f88996 [COFF] create MemoryBuffers without requiring NUL terminators
Summary:
In a number of places in the COFF linker, we were calling
MemoryBuffer::getFile() with default parameters. This causes LLVM to
NUL-terminate the buffers, which can prevent them from being memory
mapped. Since we operate on binary and do not use NUL as an indicator
of the end of the file content, this change causes us to not require
the NUL terminator anymore.

Reviewers: ruiu, pcc

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45909

llvm-svn: 330786
2018-04-24 23:16:39 +00:00
Rui Ueyama ffa650a183 Style fix.
llvm-svn: 330785
2018-04-24 23:09:57 +00:00
Rafael Espindola a8d0b87f50 Add a test. NFC.
This would have found the issue in r329960.

llvm-svn: 330784
2018-04-24 23:03:58 +00:00
Sam Clegg 1bfdabacfe [WebAssembly] Match llvm-side change to reloc section header
Differential Revision: https://reviews.llvm.org/D45795

llvm-svn: 330750
2018-04-24 18:11:47 +00:00
George Rimar de83cbf37e [ELF] - Never use std::sort.
It turns out we should not use the std::sort anymore.
r327219 added a new wrapper llvm::sort (D39245).
When EXPENSIVE_CHECKS is defined, it shuffles the
input container and that helps to find non-deterministic
ordering.

Patch changes code to use llvm::sort and std::stable_sort
instead of std::sort

Differential revision: https://reviews.llvm.org/D45969

llvm-svn: 330702
2018-04-24 09:55:39 +00:00
George Rimar 19f9b814dd [ELF] - Refactor lazy symbol duplicated code.
Our code for LazyObject and LazyArchive duplicates.

This patch extracts the common part to remove
the duplication.

Differential revision: https://reviews.llvm.org/D45516

llvm-svn: 330701
2018-04-24 09:41:56 +00:00
Zachary Turner d6fce2e9db [COFF] Alias /DEBUG:FULL to /DEBUG
With MSVC linker, /DEBUG is an alias of /DEBUG:FASTLINK, and if
you don't want /DEBUG:FASTLINK you have to explicitly specify
/DEBUG:FULL.

LLD doesn't support /DEBUG:FASTLINK, and so our standard /DEBUG
option is what MSVC calls /DEBUG:FULL.  To provide command line
compatibility with MSVC, we should also support /DEBUG:FULL, and
since it's the same as what LLD already does for /DEBUG, just
alias it.

llvm-svn: 330647
2018-04-23 20:54:08 +00:00
Rui Ueyama d134d2e509 Remove duplicate "error:" from an error message.
This patch also simplifies the code a bit which wasn't committed in
https://reviews.llvm.org/r330600.

llvm-svn: 330644
2018-04-23 20:34:35 +00:00
Zaara Syeda 25b488b0ea [PPC64] Fix toc restore nops offset for V2 ABI
The PPC64 V2 ABI restores the toc base by loading from an offset of 24 from r1.
This patch fixes the offset and updates the testcases from V1 to V2. It also
issues an error when a nop is missing after a call to an external function.

Differential Revision: https://reviews.llvm.org/D45892

llvm-svn: 330600
2018-04-23 15:01:24 +00:00
George Rimar 97df22f110 [ELF] - Simplify. NFC.
llvm-svn: 330597
2018-04-23 14:41:49 +00:00
Fangrui Song c8ac0a6f97 [ELF] Swap argument names: use Old to refer to original symbol and New for incoming one
Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D45905

llvm-svn: 330491
2018-04-20 22:50:15 +00:00
Bob Haarman 8679a7ecea Fix nullptr passed to memcpy in lld/COFF/Chunks.cpp
Summary:
ubsan found that we sometimes pass nullptr to memcpy in
SectionChunk::writeTo(). This change adds a check that avoids that.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45789

llvm-svn: 330490
2018-04-20 22:16:09 +00:00
Peter Collingbourne c8f5c05d41 COFF: Document /pdbaltpath.
llvm-svn: 330488
2018-04-20 22:11:28 +00:00
Peter Collingbourne 9106b2becd Use /pdbaltpath to avoid a path length dependency.
llvm-svn: 330485
2018-04-20 21:54:55 +00:00
Peter Collingbourne 3d636edc56 COFF: Merge .xdata into .rdata by default.
Differential Revision: https://reviews.llvm.org/D45804

llvm-svn: 330484
2018-04-20 21:32:37 +00:00
Peter Collingbourne 326f419335 COFF: Merge .bss into .data by default.
Differential Revision: https://reviews.llvm.org/D45803

llvm-svn: 330483
2018-04-20 21:30:36 +00:00
Rui Ueyama 88fe5c9557 Add -z {combreloc,copyreloc,noexecstack,lazy,relro,text}.
Differential Revision: https://reviews.llvm.org/D45902

llvm-svn: 330482
2018-04-20 21:24:08 +00:00
Peter Collingbourne 71c7de5b77 COFF: Preserve section type when processing /section flag.
It turns out that we were dropping this before.

Differential Revision: https://reviews.llvm.org/D45802

llvm-svn: 330481
2018-04-20 21:23:16 +00:00
Peter Collingbourne 381b3d8aa3 COFF: Use (name, output characteristics) as a key when grouping input sections into output sections.
This is what link.exe does and lets us avoid needing to worry about
merging output characteristics while adding input sections to output
sections.

With this change we can't process /merge in the same way as before
because sections with different output characteristics can still
be merged into one another. So this change moves the processing of
/merge to just before we assign addresses. In the case where there
are multiple output sections with the same name, link.exe only merges
the first section with the source name into the first section with
the target name, and we do the same.

At the same time I also implemented transitive merging (which means
that /merge:.c=.b /merge:.b=.a merges both .c and .b into .a).

This isn't quite enough though because link.exe has a special case for
.CRT in 32-bit mode: it processes sections whose output characteristics
are DATA | R | W as though the output characteristics were DATA | R
(so that they get merged into things like constructor lists in the
expected way). Chromium has a few such sections, and it turns out
that those sections were causing the problem that resulted in r318699
(merge .xdata into .rdata) being reverted: because of the previous
permission merging semantics, the .CRT sections were causing the entire
.rdata section to become writable, which caused the SEH runtime to
crash because it apparently requires .xdata to be read-only. This
change also implements the same special case.

This should unblock being able to merge .xdata into .rdata by default,
as well as .bss into .data, both of which will be done in followups.

Differential Revision: https://reviews.llvm.org/D45801

llvm-svn: 330479
2018-04-20 21:10:33 +00:00
Sterling Augustine 7026d3bac4 Under some scenarios, the current directory isn't writable
during a test. Set the output path to avoid that problem.

llvm-svn: 330464
2018-04-20 18:45:24 +00:00
Zachary Turner 041eb6fef6 [LLD/PDB] Remove improper assert.
It's possible to have an empty object file, for example if you
just compile an empty .c file.  This file won't have any sections
so asserting that a file has chunks is definitely wrong.

llvm-svn: 330461
2018-04-20 18:36:51 +00:00
Zachary Turner 194be871b9 [LLD/PDB] Emit first section contribution for DBI Module Descriptor.
Part of the DBI stream is a list of variable length structures
describing each module that contributes to the final executable.

One member of this structure is a section contribution entry that
describes the first section contribution in the output file for
the given module.

We have been leaving this structure unpopulated until now, so with
this patch it is now filled out correctly.

Differential Revision: https://reviews.llvm.org/D45832

llvm-svn: 330457
2018-04-20 18:00:46 +00:00
Nicholas Wilson 358af38d37 [WebAssembly] Implement -print-gc-sections, to better test GC of globals
Differential Revision: https://reviews.llvm.org/D44311

llvm-svn: 330456
2018-04-20 17:28:12 +00:00
Nicholas Wilson a1e299f58b [WebAssembly] Implement GC for imports
Differential Revision: https://reviews.llvm.org/D44313

llvm-svn: 330454
2018-04-20 17:18:06 +00:00
Nicholas Wilson 6c7fe30a1c [WebAssembly] Implement --print-gc-sections for synthetic functions
Enables cleaning up confusion between which name variables are mangled
and which are unmangled, and --print-gc-sections then excersises and
tests that.

Differential Revision: https://reviews.llvm.org/D44440

llvm-svn: 330449
2018-04-20 17:09:18 +00:00
Fangrui Song 2416d7fcb2 [ELF] --warn-backrefs: use the same GroupId for object files in the same --{start,end}-lib
Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D45849

llvm-svn: 330443
2018-04-20 16:33:01 +00:00
Rafael Espindola a59aacf52b Fix trap instruction on pp64.
The test was passing on a big endian host, but just because od with x4
was compensating for it.

llvm-svn: 330386
2018-04-20 01:21:24 +00:00
Fangrui Song b72daf00f4 [ELF] Increase NextGroupId with --end-group
Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D45846

llvm-svn: 330379
2018-04-19 23:23:23 +00:00
Sam Clegg 0dbe57e752 [WebAssembly] Fix bug where reloc addends were written as unsigned
Relocation addends can be negative so should be written as
signed LEBs. This bug meant that writing value between 64
and 128 would be incorrectly interpreted as negative by the
object file readers.

Differential Revision: https://reviews.llvm.org/D45825

llvm-svn: 330374
2018-04-19 22:48:03 +00:00
Rafael Espindola 991c1cd5f7 Add a test. NFC.
We have relatively few tests on the contents of non alloc
sections. This one would have found a bug in a patch I am working on.

llvm-svn: 330369
2018-04-19 21:58:28 +00:00
Peter Collingbourne be084eca5b COFF: Remove OutputSection::getPermissions() and getCharacteristics().
All callers can just access the header directly.

Differential Revision: https://reviews.llvm.org/D45800

llvm-svn: 330367
2018-04-19 21:48:37 +00:00
Peter Collingbourne fa322abee9 COFF: Rename Chunk::getPermissions to getOutputCharacteristics.
In an upcoming change I will need to make a distinction between section
type (code, data, bss) and permissions. The term that I use for both
of these things is "output characteristics".

Differential Revision: https://reviews.llvm.org/D45799

llvm-svn: 330361
2018-04-19 20:03:24 +00:00
Rafael Espindola 4809e2c11d Define InputSection::getOffset inline.
This is much simpler than the other section types and there are many
places where the section type is statically know.

llvm-svn: 330350
2018-04-19 18:00:46 +00:00
Rafael Espindola f4d6e8caea Simplify Repl handling.
Now that we don't ICF synthetic sections, we can go back to the old
logic on whose responsibility it is to check Repl.

The idea is that Sec->something() will not check Repl. It is the
responsibility of the caller to find the correct Sec.

llvm-svn: 330346
2018-04-19 17:26:50 +00:00
Rafael Espindola aded409325 Simplify getOffset for synthetic sections.
We had a single symbol using -1 with a synthetic section. It is
simpler to just update its value.

This is not a big will by itself, but will allow having a simple
getOffset for InputSeciton.

llvm-svn: 330340
2018-04-19 16:54:30 +00:00
Rafael Espindola 6275a7aa39 Rename MergeInputSection::getOffset.
Unlike the getOffset in the base class, this one computes the offset
in the parent synthetic section, not the final output section.

llvm-svn: 330339
2018-04-19 16:05:07 +00:00