Commit Graph

278 Commits

Author SHA1 Message Date
Rui Ueyama 1bf618a9da Remove unused condition.
Looks like all tests pass without this `isLocal()`.

Differential Revision: https://reviews.llvm.org/D39780

llvm-svn: 319395
2017-11-30 01:08:09 +00:00
Rafael Espindola dfebd3601d Use Symbol::File directly.
We are already paying the cost of storing a InputFile in every
Symbol, so use it uniformly.

llvm-svn: 319378
2017-11-29 22:47:35 +00:00
Rafael Espindola b262cbe6b7 Replace copyFrom with memcpy.
It was only used for --wrap and I don't think the fields with special
treatment had a meaningful impact on that feature.

llvm-svn: 319265
2017-11-29 00:31:39 +00:00
Rafael Espindola 97d05f95b9 Copy the visibility in copyFrom.
This is simpler and matches bfd's behavior on the changed test.

llvm-svn: 319248
2017-11-28 23:06:09 +00:00
Rafael Espindola b45c164fc2 Handle binding in --wrap.
Copying the binding seems reasonable and matches the bfd behavior.

llvm-svn: 319196
2017-11-28 18:02:22 +00:00
Rui Ueyama 53fe469162 Factor out common code to Common/Strings.cpp.
Differential Revision: https://reviews.llvm.org/D40530

llvm-svn: 319138
2017-11-28 02:15:26 +00:00
Rui Ueyama 7957b08e87 Move MIPS-specific code from Symbols.cpp to MIPS.cpp.
We have a lot of "if (MIPS)" conditions in lld because the MIPS' ABI
is different at various places than other arch's ABIs at where it
don't have to be different, but we at least want to reduce MIPS-ness
from the regular classes.

llvm-svn: 317525
2017-11-07 00:04:22 +00:00
Peter Collingbourne b472aa0268 ELF: Remove function Symbol::isInCurrentOutput().
This function is now equivalent to isDefined().

llvm-svn: 317449
2017-11-06 04:39:07 +00:00
Peter Collingbourne e9a9e0a1e7 ELF: Merge DefinedRegular and Defined.
Now that DefinedRegular is the only remaining derived class of
Defined, we can merge the two classes.

Differential Revision: https://reviews.llvm.org/D39667

llvm-svn: 317448
2017-11-06 04:35:31 +00:00
Peter Collingbourne 6c55a70838 ELF: Remove DefinedCommon.
Common symbols are now represented with a DefinedRegular that points
to a BssSection, even during symbol resolution.

Differential Revision: https://reviews.llvm.org/D39666

llvm-svn: 317447
2017-11-06 04:33:58 +00:00
Rui Ueyama 48882249dd Rename Body -> Sym.
This patch is mechanically created by

  sed -i -e s/Body/Sym/g lld/ELF/*.{cpp,h}

and clang-format-diff.

llvm-svn: 317392
2017-11-04 00:31:04 +00:00
Rui Ueyama f52496e1e0 Rename SymbolBody -> Symbol
Now that we have only SymbolBody as the symbol class. So, "SymbolBody"
is a bit strange name now. This is a mechanical change generated by

  perl -i -pe s/SymbolBody/Symbol/g $(git grep -l SymbolBody lld/ELF lld/COFF)

nd clang-format-diff.

Differential Revision: https://reviews.llvm.org/D39459

llvm-svn: 317370
2017-11-03 21:21:47 +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
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 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
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
Bob Haarman b8a59c8aa5 [lld] unified COFF and ELF error handling on new Common/ErrorHandler
Summary:
The COFF linker and the ELF linker have long had similar but separate
Error.h and Error.cpp files to implement error handling. This change
introduces new error handling code in Common/ErrorHandler.h, changes the
COFF and ELF linkers to use it, and removes the old, separate
implementations.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: smeenai, jyknight, emaste, sdardis, nemanjai, nhaehnle, mgorny, javed.absar, kbarton, fedor.sergeev, llvm-commits

Differential Revision: https://reviews.llvm.org/D39259

llvm-svn: 316624
2017-10-25 22:28:38 +00:00
Rafael Espindola 9c8f853ca9 Refactor duplicated comment. NFC.
llvm-svn: 316455
2017-10-24 16:27:31 +00:00
Shoaib Meenai ba23183ba7 [LLD] Fix typo. NFC
llvm-svn: 315675
2017-10-13 06:11:20 +00:00
Rui Ueyama 662bb00028 Hide SymbolBody::IsLocal.
IsLocal member is initialized by the constructor and will never change.
So we don't want to make it directly accessible.

llvm-svn: 315667
2017-10-13 03:37:26 +00:00
Rui Ueyama ce2f5fdbb8 Add comment.
llvm-svn: 315664
2017-10-13 02:57:59 +00:00
Ben Dunbobbin 73eabf23a4 [ELF] Simpler scheme for handling common symbols
Convert all common symbols to regular symbols after scan.
This means that the downstream code does not to handle common symbols as a special case.

Differential Revision: https://reviews.llvm.org/D38137

llvm-svn: 314495
2017-09-29 09:08:26 +00:00
Rui Ueyama 5bbe4a4deb Rename copy -> copyFrom.
This patch is to improve code readability.

llvm-svn: 314089
2017-09-25 00:57:30 +00:00
Rafael Espindola e05e2f8b34 Keep some relocations with undefined weak symbols.
This fixes pr34301.

As the bug points out, we want to keep some relocations with undefined
weak symbols. This means that we cannot always claim that these
symbols are not preemptible as we do now.

Unfortunately, we cannot also just always claim that they are
preemptible. Doing so would, for example, cause us to try to create a
plt entry when we don't even have a dynamic symbol table.

What almost works is to say that weak undefined symbols are
preemptible if and only if we have a dynamic symbol table. Almost
because we don't want to fail the build trying to create a copy
relocation to a weak undefined.

llvm-svn: 313372
2017-09-15 18:05:02 +00:00
Rafael Espindola c57f8cd7ea Simplify. NFC.
The isShared case was handled by the isInCurrentDSO check.

llvm-svn: 313190
2017-09-13 20:47:53 +00:00
Rafael Espindola 3d9f1c032a Add a helper for checking for weak undef. NFC.
llvm-svn: 313188
2017-09-13 20:43:04 +00:00
Rafael Espindola f6c74c472d Remove CopyRelSecOff from SharedSymbol.
This reduces the size of SharedSymbol which in turn reduces the size
of Symbol from 88 to 80 bytes.

llvm-svn: 313154
2017-09-13 16:59:12 +00:00
Rafael Espindola 7415819186 Handle lazy symbols is Symbol::includeInDynsym.
This should fix the lto bootstrap.

It is somewhat hard to remember about lazy symbols deep down in the
link. It might be worth it replacing them with undefined symbols once
we are done adding files.

llvm-svn: 313103
2017-09-13 00:47:06 +00:00
Ben Dunbobbin 0b95d3784a [ELF] Handle references to garbage collected common symbols
https://reviews.llvm.org/rL312796 meant that references to garbage collected common symbols would cause a segfault.

This change fixes the behaviour for references to stripped common symbols.

Differential Revision: https://reviews.llvm.org/D37718

llvm-svn: 313086
2017-09-12 22:41:45 +00:00
Rafael Espindola 67df57a242 Remove Offset from Common.
It is not needed since it is always 0.

llvm-svn: 313076
2017-09-12 21:19:09 +00:00
Dmitry Mikulin 1e30f07ce7 Currently lld creates a single section to collect all commons. There is no way
to separate commons based on file name patterns. The following linker script
construct does not work because commons are allocated before section placement
is done and the only synthesized BssSection that holds all commons has no file
associated with it:
SECTIONS { .common_0 : { *file0.o(COMMON) }}

This patch changes the allocation of commons to create a section per common
symbol and let the section logic do the layout.

Differential revision: https://reviews.llvm.org/D37489

llvm-svn: 312796
2017-09-08 16:22:43 +00:00
Rafael Espindola db1af69342 Avoid crash with local abs symbol.
llvm-svn: 310736
2017-08-11 17:47:12 +00:00
Rui Ueyama 9c77d27004 Garbage-collect common symbols.
Liveness is usually a notion of input sections, but this patch adds
"liveness" bit to common symbols because they don't belong to any
input section.

This patch is based on https://reviews.llvm.org/D36520

Differential Revision: https://reviews.llvm.org/D36546

llvm-svn: 310617
2017-08-10 15:54:27 +00:00
Rafael Espindola 35c908f20c Compute isPreemtible only once.
This is probably a small optimization, but the main motivation is
having a way of fixing pr34053 that doesn't require a hash lookup in
isPreempitible.

llvm-svn: 310602
2017-08-10 15:05:37 +00:00
Rafael Espindola 6e93d0546a Move File from SymbolBody to Symbol.
With this Symbol has the same size as before, but DefinedRegular goes
from 72 to 64 bytes.

I also find this a bit easier to read. There are fewer places
initializing File for example.

This has a small but measurable speed improvement on all tests (1%
max).

llvm-svn: 310142
2017-08-04 22:31:42 +00:00
Rafael Espindola 0afcef27a1 Remove redundant flag.
llvm-svn: 310079
2017-08-04 17:43:54 +00:00
George Rimar b0d9fbeeeb [ELF] - Recommit r309252 "[ELF] - Fix missing relocation when linking executable with --unresolved-symbols=ignore-all"
With fix for undefined weak symbols in executable.

Original commit message:
This is PR32112. Previously when we linked executable with 
--unresolved-symbols=ignore-all and undefined symbols, like:

_start:
callq und@PLT

we did not create relocations, though it looks in that case
we should delegate handling of such symbols to runtime linker,
hence should emit them. Patch fixes that.

Differential revision: https://reviews.llvm.org/D35724

llvm-svn: 309796
2017-08-02 07:51:08 +00:00
Rafael Espindola aee5a8743e Never export weak undefined from executable.
Before we were doing it with --export-dynamic. That seems incorrect.
The intention of --export-dynamic is to export symbols *defined* in
the executable.

llvm-svn: 309605
2017-07-31 18:52:47 +00:00
George Rimar 13f7dcdbc3 Revert r309252 "[ELF] - Fix missing relocation when linking executable with --unresolved-symbols=ignore-all"
It broke bot:
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/4231

llvm-svn: 309258
2017-07-27 09:25:16 +00:00
George Rimar 678188d48b [ELF] - Fix missing relocation when linking executable with --unresolved-symbols=ignore-all
This is PR32112. Previously when we linked executable with 
--unresolved-symbols=ignore-all and undefined symbols, like:

_start:
callq und@PLT

we did not create relocations, though it looks in that case
we should delegate handling of such symbols to runtime linker,
hence should emit them. Patch fixes that.

Differential revision: https://reviews.llvm.org/D35724

llvm-svn: 309252
2017-07-27 07:31:31 +00:00
Rui Ueyama 709fb2bb10 Rename ObjectFile -> ObjFile.
Rename it because it was too easy to conflict with llvm::object::ObjectFile
which broke buildbots several times.

llvm-svn: 309199
2017-07-26 22:13:32 +00:00
Peter Collingbourne 3e2abdef02 ELF: Reword a somewhat misleading error message.
PT_TLS is a type of program header, so we wouldn't expect to see
one in an object file. This error should probably be referring to
the fact that we didn't see a section with the flag SHF_TLS, which
would normally cause us to create a PT_TLS program header.

Differential Revision: https://reviews.llvm.org/D35395

llvm-svn: 307983
2017-07-14 00:22:46 +00:00
Rafael Espindola cf00d4374e Fix PR33635.
This is a semantic revert of r306036.

We have to change the names, otherwise dynamic relocations will point
to the wrong name.

llvm-svn: 307110
2017-07-05 00:43:18 +00:00
George Rimar 4d2f976208 [ELF] - Resolve references properly when using .symver directive
This is PR28414. 
Previously LLD was unable to link following:
(failed with undefined symbol bar)

Version script:
SOME_VERSION { global: *; };

.global _start
.global bar
.symver _start, bar@@SOME_VERSION
_start:
  jmp bar
Manual has next description:

.symver name, name2@@nodename
In this case, the symbol name must exist and be defined within the file being assembled. It is similar to name2@nodename. 
The difference is name2@@nodename will also be used to resolve references to name2 by the linker
https://sourceware.org/binutils/docs/as/Symver.html

Patch implements that. If we have name@@ver symbol and name is undefined, name@@ver is used to resolve references to name.
If name is defined then multiple definition error is emited, that is consistent with what bfd do.

Differential revision: https://reviews.llvm.org/D33680

llvm-svn: 307077
2017-07-04 13:19:13 +00:00
Rui Ueyama b2269ec4d3 Move copy function from Symbol to SymbolBody.
We could have add this function either Symbol or SymbolBody. I added it
to Symbol at first. But I noticed that if I've added it to SymbolBody,
we could've removed SymbolBody::setName(). So I'll do that in this patch.

llvm-svn: 306590
2017-06-28 19:43:02 +00:00
Rui Ueyama 8e11b6d94b Define Symbol::copyBody function.
This patch adds a utility function to Symbol. This function should
be useful in https://reviews.llvm.org/D33680 too.

llvm-svn: 306587
2017-06-28 19:28:49 +00:00
Rui Ueyama 92c3781959 Add GlobalOffsetTable to ElfSym. NFC.
Most "reserved" symbols are in ElfSym and it looks like there's no
reason to not do the same thing for _GLOBAL_OFFSET_TABLE_. This should
help https://reviews.llvm.org/D34618 too.

llvm-svn: 306292
2017-06-26 15:11:24 +00:00
Rui Ueyama d97265f792 Simplify. NFC.
llvm-svn: 305112
2017-06-09 21:09:08 +00:00
Rafael Espindola db5e56f7b2 Store a single Parent pointer for InputSectionBase.
Before InputSectionBase had an OutputSection pointer, but that was not
always valid. For example, if it was a merge section one actually had
to look at MergeSec->OutSec.

This was brittle and caused bugs like the one fixed by r304260.

We now have a single Parent pointer that points to an OutputSection
for InputSection, but to a SyntheticSection for merge sections and
.eh_frame. This makes it impossible to accidentally access an invalid
OutSec.

llvm-svn: 304338
2017-05-31 20:17:44 +00:00