Commit Graph

9481 Commits

Author SHA1 Message Date
George Rimar 1b45d377e3 [ELF] - Cleanup of processSectionCommands().
The way we handle ONLY_IF_RO/ONLY_IF_RW constraints in
processSectionCommands is a bit tricky. If input sections
does no satisfy given constraint we remove command from
commands list. It seems too complex, what we can do instead
is to make the OutputCommand empty. So that at later steps
LLD will remove it just like it deal with other empty output commands.
That allows to simplify the loop a bit.

Differential revision: https://reviews.llvm.org/D39094

llvm-svn: 317082
2017-11-01 08:40:28 +00:00
George Rimar 82f0c42dad [ELF] - Teach LLD to report line numbers for data symbols.
This is PR34826.

Currently LLD is unable to report line number when reporting
duplicate declaration of some variable.

That happens because for extracting line information we always use
.debug_line section content which describes mapping from machine
instructions to source file locations, what does not help for
variables as does not describe them.

In this patch I am taking the approproate information about
variables locations from the .debug_info section.

Differential revision: https://reviews.llvm.org/D38721

llvm-svn: 317080
2017-11-01 07:42:38 +00:00
Rui Ueyama 700b1f8a56 Add --no-omagic and --no-print-gc-sections.
llvm-svn: 317068
2017-11-01 02:04:43 +00:00
Rui Ueyama 9fa2813803 Do not access beyond the end of local symbols.
This patch resurrects code that was removed in r317007 to not access
beyond allocated memory for a symbol.

Differential Revision: https://reviews.llvm.org/D39458

llvm-svn: 317039
2017-10-31 21:26:42 +00:00
Rui Ueyama 95c142e208 Revert r316305: Remove a fast lookup table from MergeInputSection.
This reverts commit r316305 because performance regression was observed.

llvm-svn: 317026
2017-10-31 19:14:06 +00:00
James Henderson 50baa593f1 [ELF] Remove unnecessary function call. NFC.
StringTableSection does not implement postThunkContents, so calling it on these 
sections is pointless (it calls an empty virtual function), and we can remove it.

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D39460

llvm-svn: 317014
2017-10-31 17:28:44 +00:00
Rui Ueyama f78d097340 Remove a redundant union member.
This removes DefinedCOFF from SymbolUnion because DefinedCOFF is
not a leaf class. Pointed out by pcc.

llvm-svn: 317013
2017-10-31 17:07:47 +00:00
Rui Ueyama 616cd99194 [COFF] Merge Symbol and SymbolBody.
llvm-svn: 317007
2017-10-31 16:10:24 +00:00
Rui Ueyama f1f00841d9 Merge SymbolBody and Symbol into one class, SymbolBody.
SymbolBody and Symbol were separated classes due to a historical reason.
Symbol used to be a pointer to a SymbolBody, and the relationship
between Symbol and SymbolBody was n:1.

r2681780 changed that. Since that patch, SymbolBody and Symbol are
allocated next to each other to improve memory locality, and they have
1:1 relationship now. So, the separation of Symbol and SymbolBody no
longer makes sense.

This patch merges them into one class. In order to avoid updating too
many places, I chose SymbolBody as a unified name. I'll rename it Symbol
in a follow-up patch.

Differential Revision: https://reviews.llvm.org/D39406

llvm-svn: 317006
2017-10-31 16:07:41 +00:00
George Rimar f173a6309f [ELF] - Remove useless code. NFC.
We set Type and Flags inside OutputSection::addSection,
so this lines looks to be excessive.

llvm-svn: 317002
2017-10-31 14:21:30 +00:00
Oleg Ranevskyy 0cf24ed9aa [lld] Fix --exclude-libs broken when --whole-archive is used
Summary:
**Problem**
`--exclude-libs` does not work for static libraries affected by the `--whole-archive` option.

**Description**
`--exclude-libs` creates a list of static library paths and does library lookups in this list.
`--whole-archive` splits the static libraries that follow it into separate objects. As a result, lld no longer sees static libraries among linked files and does no `--exclude-libs` lookups.

**Solution**
The proposed solution is to make `--exclude-libs` consider object files too. When lld finds an object file it checks whether this file originates from an archive and, if so, looks the archive up in the `--exclude-libs` list.

Reviewers: ruiu, rafael

Reviewed By: ruiu

Subscribers: asl, ikudrin, llvm-commits, emaste

Tags: #lld

Differential Revision: https://reviews.llvm.org/D39353

llvm-svn: 316998
2017-10-31 13:51:06 +00:00
George Rimar f9b04fd91f [ELF] - Simplify output section creation.
When there is no SECTION commands given, all sections are
technically orphans, but now we handle script orphans sections
and regular "orphans" sections for non-scripted case differently,
though we can handle them at one place.

Patch do that change.

Differential revision: https://reviews.llvm.org/D39045

llvm-svn: 316984
2017-10-31 10:31:58 +00:00
Jake Ehrlich 1128dc5e30 Give .note.gnu.build-id section alignment 4
All SHT_NOTE sections should have minimum alignment 4.

Differential Revision: https://reviews.llvm.org/D38907

llvm-svn: 316961
2017-10-30 22:08:11 +00:00
Rafael Espindola 458173e802 Use 64 bits for the shared symbol size again.
We might want to drop support for such large symbols, but that should
be an explicit decision with a testcase.

llvm-svn: 316931
2017-10-30 17:43:16 +00:00
Rafael Espindola 566dbdc2fd Skip abs symbols when handling copy reloc aliases.
Since we now only check st_value, we have to consider the case where
the section index is special.

llvm-svn: 316928
2017-10-30 17:26:12 +00:00
George Rimar a6b1fbece1 [ELF] - Stop sorting input sections in createSections().
It does not seem that createSections() is a good place for
applying sorting. Patch changes code to do that inside
sortSections(), which looks more appropriate place.

Differential revision: https://reviews.llvm.org/D39371

llvm-svn: 316893
2017-10-30 10:12:49 +00:00
Rui Ueyama 27f95a9ac3 Remove unnecessary code.
Discarded section's Repl always points to itself, so returning
Sec is not different from returning Sec->Repl.

llvm-svn: 316880
2017-10-29 23:41:16 +00:00
Rui Ueyama ea1398eeb3 Move "Assigned" bit from SectionBase to InputSectionBase.
This bit is to manage whether an input section has already been assigned
to some output section by linker scripts or not. So it logically belongs
to InputSectionBase. SectionBase is a common base class for input and
output sections, so that wasn't the right place to define the bit.

llvm-svn: 316879
2017-10-29 23:32:23 +00:00
Rui Ueyama 63edd9f831 Remove an obscure comment.
llvm-svn: 316878
2017-10-29 22:38:00 +00:00
Peter Collingbourne e662436114 ELF: Correctly set edata if there are no .bss sections.
edata needs to be set to the end of the last mapped initialized
section. We were previously mishandling the case where there were no
non-mapped sections by setting it to the end of the last section in
the output file.

Differential Revision: https://reviews.llvm.org/D39399

llvm-svn: 316877
2017-10-29 22:31:48 +00:00
Rui Ueyama da4d26dfa3 Initialize members not by assignment but by the member initializer list.
llvm-svn: 316876
2017-10-29 22:26:52 +00:00
Rui Ueyama b6f4e722b1 Fix ubsan error that shift amount 64 is too large.
llvm-svn: 316863
2017-10-29 16:49:42 +00:00
Rui Ueyama ac6472535b Remove a redundant temporary variable.
llvm-svn: 316862
2017-10-29 16:46:39 +00:00
Rui Ueyama da42135cef Fix ubsan error.
This patch fixes ubsan's "shift exponent 64 is too large for 32-bit type
'int'" error.

llvm-svn: 316849
2017-10-28 22:18:29 +00:00
Rui Ueyama bd730e3ca7 Reduce sizeof(Symbol) from 104 bytes to 88 bytes.
Finding aliases for shared symbols doesn't need st_shndx because
we can just compare st_value.

llvm-svn: 316848
2017-10-28 22:18:17 +00:00
Rui Ueyama 4a22edabec Do not handle DefinedCommon symbols in the MapFile writer.
Because of r314495 which converts DefinedCommon symbols to DefinedRegular
symbols, common symbols are no longer reachable to the MapFile writer.
So the code to handle common symbols is now dead.

llvm-svn: 316846
2017-10-28 21:11:38 +00:00
Rui Ueyama 1392e84caf Rename V -> Ver for readability.
llvm-svn: 316842
2017-10-28 20:16:11 +00:00
Rui Ueyama 7f9694a42d Pass symbol attributes instead of ElfSym to Shared symbol ctor.
This change allows us to use less templates for Shared symbol and
the functions that deals with shared symbols.

llvm-svn: 316841
2017-10-28 20:15:56 +00:00
Rui Ueyama f405b11224 Simplify error handling.
I don't think we have to aim for precise bug compatibility.
We can return a nullptr if a section is consumed by the linker, and
the rest should naturally work.

llvm-svn: 316817
2017-10-28 00:05:12 +00:00
Rui Ueyama da524d021a Remove unnecessary namespace specifiers.
llvm-svn: 316812
2017-10-27 23:29:58 +00:00
Rui Ueyama 7833afdd6b Inline trivial symbol constructors.
llvm-svn: 316811
2017-10-27 23:26:46 +00:00
Rui Ueyama bda337a8d8 Rename isInCurrentDSO -> isInCurrentOutput.
DSO is short for dynamic shared object, so the function name was a
little confusing because it sounded like it didn't work when we were
a creating statically-linked executable or something.

What we mean by "DSO" here is the current output file that we are
creating. Thus the new name. Alternatively, we could call it the current
ELF module, but "module" is a overloaded word, so I avoided that.

llvm-svn: 316809
2017-10-27 22:54:16 +00:00
Rui Ueyama 8f6e8ed9dd Remove trailing whitespace.
llvm-svn: 316787
2017-10-27 19:23:12 +00:00
Rafael Espindola bc2b1650d7 Handle all symbol types in --trace.
One case I was not sure was lazy symbols. bfd skips them completely,
but that is probably an artifact of how they implement archives.

llvm-svn: 316782
2017-10-27 18:30:11 +00:00
Rui Ueyama 3fa55c5026 Instead of enclosing an entire file, add lld:: specifier for public functions.
llvm-svn: 316776
2017-10-27 18:04:49 +00:00
Peter Collingbourne 5c54f15c55 ELF: Add support for emitting dynamic relocations in the Android relocation packing format.
The Android relocation packing format is a more compact
format for dynamic relocations in executables and DSOs
that is based on delta encoding and SLEBs. An overview
of the format can be found in the Android source code:
https://android.googlesource.com/platform/bionic/+/refs/heads/master/tools/relocation_packer/src/delta_encoder.h

This patch implements relocation packing using that format.

This implementation uses a more intelligent algorithm for compressing
relative relocations than Android's own relocation packer. As a
result it can generally create smaller relocation sections than
that packer. If I link Chromium for Android targeting ARM32 I get a
.rel.dyn of size 174693 bytes, as compared to 371832 bytes with gold
and the Android packer.

Differential Revision: https://reviews.llvm.org/D39152

llvm-svn: 316775
2017-10-27 17:49:40 +00:00
George Rimar 90dacc256f [ELF] - Ignore non-absolute R_386_GOTPC relocation in debug sections.
This is for PR34852.

GCC 8.0 or earlier have a bug that it emits R_386_GOTPC relocations
against _GLOBAL_OFFSET_TABLE for .debug_info. The bug seems to have
been fixed in 2017: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82630,
but we do not want LLD to report errors for such inputs.
In this patch we ignore such relocations.

Differential revision: https://reviews.llvm.org/D38625

llvm-svn: 316761
2017-10-27 11:49:24 +00:00
George Rimar 3396bf07a2 [ELF] - Stop naming relocation sections with first input section name.
It was reported (https://reviews.llvm.org/D38724#902841) that when we use 
-ffunction-sections --emit-relocs build, REL[A] output section receives the name of first
input section, like .rela.text.first_function_in_text rather than .rela.text.

It is probably not really an issue as sh_info still points to correct target section, but
it does not look clean in output and allows internal section name to leak there,
what at least looks confusing and is not consistent with ld.bfd.

Patch changes this behavior so that target output section name is used as a base.

Differential revision: https://reviews.llvm.org/D39242

llvm-svn: 316760
2017-10-27 11:38:31 +00:00
George Rimar 96b1157814 [ELF] - Simplify reporting of garbage collected sections.
This moves reporting of garbage collected sections right after
we do GC. That simplifies things.

Differential revision: https://reviews.llvm.org/D39058

llvm-svn: 316759
2017-10-27 11:32:22 +00:00
Peter Smith 7f92294e9b [ELF][ARM] Add missing REQUIRES: arm to tests
My apologies I missed REQUIRES: arm from a couple of Arm specific tests.

llvm-svn: 316755
2017-10-27 09:16:46 +00:00
Peter Smith 6c9df3fce5 [ELF] Add support for multiple passes to createThunks()
This change allows Thunks to be added on multiple passes. To do this we must
merge only the thunks added in each pass, and deal with thunks that have
drifted out of range of their callers.

A thunk may end out of range of its caller if enough thunks are added in
between the caller and the thunk. To handle this we create another thunk.

Differential Revision: https://reviews.llvm.org/D34692

llvm-svn: 316754
2017-10-27 09:07:10 +00:00
Peter Smith 75030b6d56 [ELF] Introduce range extension thunks for ARM
This change adds initial support for range extension thunks. All thunks must
be created within the first pass so some corner cases are not supported. A
follow up patch will add support for multiple passes.

With this change the existing tests arm-branch-error.s and
arm-thumb-branch-error.s now no longer fail with an out of range branch.
These have been renamed and tests added for the range extension thunk.

Differential Revision: https://reviews.llvm.org/D34691

llvm-svn: 316752
2017-10-27 09:04:11 +00:00
Peter Smith f0c70f8d34 [ELF] Pre-create ThunkSections at Target specific intervals
When an OutputSection is larger than the branch range for a Target we
need to place thunks such that they are always in range of their caller,
and sufficiently spaced to maximise the number of callers that can use
the thunk. We use the simple heuristic of placing the
ThunkSection at intervals corresponding to a target specific branch range.
If the OutputSection is small we put the thunks at the end of the executable
sections.

Differential Revision: https://reviews.llvm.org/D34689

llvm-svn: 316751
2017-10-27 08:58:28 +00:00
Peter Smith 4a8e11595c [ELF] Record created ThunkSections in InputSectionDescription [NFC].
Instead of maintaining a map of the std::vector to ThunkSections, record the
ThunkSections directly in InputSectionDescription.

Differential Revision: https://reviews.llvm.org/D37743

llvm-svn: 316750
2017-10-27 08:56:20 +00:00
Rui Ueyama 0f46e45b03 Simplify logic to find the last executable segment. NFC.
llvm-svn: 316742
2017-10-27 05:08:39 +00:00
Rui Ueyama df15559c80 Fix typo.
llvm-svn: 316741
2017-10-27 04:59:33 +00:00
Rui Ueyama f9c66e4b80 Remove a boolean flag `Create`. NFC.
llvm-svn: 316738
2017-10-27 04:15:28 +00:00
Rui Ueyama 79048e4c5c Define a file-local write32 as a wrapper for endian::write32.
llvm-svn: 316736
2017-10-27 03:59:34 +00:00
Rui Ueyama 25f30880f5 Do not use InputSection::getFile<ELFT>() if InputSection::File suffices. NFC.
llvm-svn: 316735
2017-10-27 03:25:04 +00:00
Rui Ueyama 02551abdca De-template EhFrameHdr. NFC.
llvm-svn: 316734
2017-10-27 03:14:24 +00:00