Commit Graph

516 Commits

Author SHA1 Message Date
Sean Fertile 1a8343fce3 [PPC64] Support R_PPC64_GOT_TLSLD16 relocations.
Add support for the R_PPC64_GOT_TLSLD16 relocations used to build the address of
the tls_index struct used in local-dynamic tls.

Differential Revision: https://reviews.llvm.org/D47538

llvm-svn: 333681
2018-05-31 18:44:12 +00:00
Sean Fertile fb613e552a Rename R_TLSGD/R_TLSLD to add _GOT_FROM_END. NFC.
getRelocTargetVA for R_TLSGD and R_TLSLD RelExprs calculate an offset from the
end of the got, so adjust the names to reflect this.

Differential Revision: https://reviews.llvm.org/D47379

llvm-svn: 333674
2018-05-31 18:07:06 +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
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
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
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
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
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
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 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
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
Rafael Espindola 9c680301b0 Simplify. NFC.
Using getOffset is here was a bit of an overkill. This is being
written and has relocations. This implies it is a .eh_frame or regular
section.

llvm-svn: 330307
2018-04-19 03:51:26 +00:00
Rafael Espindola 719fcd08c6 Don't call getOffset twice. NFC.
Just a bit faster.

llvm-svn: 330306
2018-04-19 02:24:28 +00:00
Rafael Espindola 9b6a65b144 Don't ignore addend when a SHF_MERGE section is dead.
This is similar to r329219, but for the entire section. Like r329219 I
don't expect this to have any real impact, it is just more consistent
and simpler.

llvm-svn: 329367
2018-04-06 01:10:33 +00:00
Rafael Espindola 7bd45502fe Initialize OffsetMap earlier.
Now that getSectionPiece uses OffsetMap, it is advantageous to
initialize it earlier.

llvm-svn: 329242
2018-04-05 00:01:57 +00:00
Rafael Espindola f7c5a10e55 Don't ignore addend in getOffset.
We were ignoring the addend if the piece was dead. I don't expect this
to make a difference in any real world situations, but it is simpler
anyway.

llvm-svn: 329219
2018-04-04 19:13:30 +00:00
Rafael Espindola 6cd7af51e1 Inline initOffsetMap.
In the lld perf builder r328686 had a negative impact in
stalled-cycles-frontend. Somehow that stat is not showing on my
machine, but the attached patch shows an improvement on cache-misses,
which is probably a reasonable proxy.

My working theory is that given a large input the pieces vector is out
of cache by the time initOffsetMap runs.

Both finalizeContents implementation have a convenient location for
initializing the OffsetMap, so this seems the best solution.

llvm-svn: 329117
2018-04-03 21:38:18 +00:00
Rafael Espindola 95f8d303ab Use OffsetMap in getSectionPiece.
OffsetMap maps to a SectionPiece index, but we were not taking
advantage of that in getSectionPiece.

With this patch both getOffset and getSectionPiece use OffsetMap and
the binary search is moved to findSectionPiece.

llvm-svn: 329044
2018-04-03 04:06:14 +00:00
Rafael Espindola 816127ea17 Initialize OffsetMap in a known location.
This is a small optimization and avoids the need to use call_once.

llvm-svn: 328686
2018-03-28 03:20:18 +00:00
Rafael Espindola 92eba0e14a Define a trivial method inline.
llvm-svn: 328685
2018-03-28 03:14:11 +00:00
Rafael Espindola 5a7ca96e2d Store live offsets as uint32_t.
We don't support input merge sections larger than 4gb, so these can be
uint32_t.

llvm-svn: 328684
2018-03-28 02:32:31 +00:00
Rafael Espindola f065390f6c Reduce code duplication a bit. NFC
llvm-svn: 328569
2018-03-26 18:49:31 +00:00
Rafael Espindola 4f058a2c6b Add a SectionBase::getVA helper. NFC.
There were a few too many places duplicating this.

llvm-svn: 328402
2018-03-24 00:35:11 +00:00
Rafael Espindola 4bb482eeac Move a Repl access.
Since SectionBase::getOutputSection handles ICF replaces and
SectionBase::getOffset was handling it in some cases, it is more
consistent to have getOffset always handle it.

llvm-svn: 328391
2018-03-23 23:55:49 +00:00
Rafael Espindola 4376cffb57 Add a minimal fix for PR36878.
When looking for the output section and the output offset the
expectation was that the caller had looked at Repl. That works fine
for InputSections, but in the case of MergeInputSections the caller
doesn't have the section that is actually replaced.

The original testcase was failing because getOutputSection was
returning null. The slightly extended testcase also checks that
getOffset also checks Repl.

I will send a refactoring separetelly.

llvm-svn: 328332
2018-03-23 17:19:18 +00:00
George Rimar 1136ec64e8 [ELF] - Fix crash relative to SHF_LINK_ORDER sections.
Our code assumes all input sections in an output SHF_LINK_ORDER
section has SHF_LINK_ORDER flag. We do not check that and that can cause a crash.

That happens because we call 
std::stable_sort(Sections.begin(), Sections.end(), compareByFilePosition);, 
where compareByFilePosition predicate does not expect to see
null when calls getLinkOrderDep. 

The same might happen when sections refer to non-regular sections. 
Test cases demonstrate the issues, patch fixes them.

Differential revision: https://reviews.llvm.org/D44193

llvm-svn: 327006
2018-03-08 15:06:58 +00:00
George Rimar aa359f87e8 [ELF] - Revert r325877 "[ELF] - Do not crash with --emit-relocs and --icf=all together."
Not latest version of patch was committed by mistake.

llvm-svn: 325878
2018-02-23 10:30:31 +00:00
George Rimar cde84d1cd0 [ELF] - Do not crash with --emit-relocs and --icf=all together.
Previously we would crash because did not mark .rel[a] sections
as dead and they tried to access parent which was not live
after ICF and therefore was null.

Differential revision: https://reviews.llvm.org/D43241

llvm-svn: 325877
2018-02-23 10:27:13 +00:00
Alexander Richardson cfb6093379 Ensure that Elf_Rel addends are always written for dynamic relocations
Summary:
This follows up on r321889 where writing of Elf_Rel addends was partially
moved to RelocationBaseSection. This patch ensures that the addends are
always written to the output section when a input section uses RELA but the
output is REL.

Differential Revision: https://reviews.llvm.org/D42843

llvm-svn: 325328
2018-02-16 10:01:17 +00:00
Igor Kudrin 943f62d9d7 [ELF] Fix use after free in case of using --whole-archive.
Differential Revision: https://reviews.llvm.org/D34554

llvm-svn: 325313
2018-02-16 03:26:53 +00:00
Rui Ueyama 65b620be8a Relax relocation type checking in a non-ALLOC section.
Even though it doesn't make sense, there seems to be multiple programs
in the wild that create PC-relative relocations in non-ALLOC sections.
I believe this is caused by the negligence of GNU linkers to not report
any errors for such relocations.

Currently, lld emits warnings against such relocations and exits.
So, you cannot link any program that contains wrong relocations until
you fix an issue in a program that generates wrong ELF files. It's often
impractical to fix a program because it's not always easy.

This patch relaxes the error checking and emit a warning instead.

Differential Revision: https://reviews.llvm.org/D43351

llvm-svn: 325307
2018-02-16 01:10:51 +00:00
Rui Ueyama 005e7c3d75 Do not use Decompressor::isCompressedELFSection. NFC.
In order to identify a compressed section, we check if a section name
starts with ".zdebug" or the section has SHF_COMPRESSED flag. We already
use the knowledge in this function. So hiding that check in
isCompressedELFSection doesn't make sense.

llvm-svn: 324951
2018-02-12 22:32:57 +00:00
Rui Ueyama 3cd48fb124 Remove 'z' in .zdebug when decompressing a section.
When decompressing a compressed debug section, we drop SHF_COMPRESSED
flag but we didn't drop "z" in ".zdebug" section name. This patch does
that for consistency.

This change also fixes the issue that .zdebug_gnu_pubnames are not
dropped when we are creating a .gdb_index section.

llvm-svn: 324949
2018-02-12 22:25:45 +00:00
Rui Ueyama ac114d27ae s/uncompress/decompress/g.
In lld, we use both "uncompress" and "decompress" which is confusing.
Since LLVM uses "decompress", we should use the same term.

llvm-svn: 324944
2018-02-12 21:56:14 +00:00
Simon Atanasyan 436046630d [ELF][MIPS] Change format of output relocations to Elf_Rel
Initially LLD generates Elf_Rel relocations for O32 ABI and Elf_Rela
relocations for N32 / N64 ABIs. In other words, format of input and
output relocations was always the same. Now LLD generates all output
relocations using Elf_Rel format only. It conforms to ABIs requirement.

The patch suggested by Alexander Richardson.

llvm-svn: 324064
2018-02-02 09:50:07 +00:00
Rafael Espindola c7945c827d Move function to the file where it is used.
llvm-svn: 323780
2018-01-30 16:24:04 +00:00
Rafael Espindola 8d13b213d4 Simplify handling of size relocations.
This is possible now that getSize is not a template.

llvm-svn: 321900
2018-01-05 21:41:17 +00:00
Rafael Espindola 9a84f6b954 Detemplate reportDuplicate.
We normally avoid "switch (Config->EKind)", but in this case I think
it is worth it.

It is only executed when there is an error and it allows detemplating
a lot of code.

llvm-svn: 321404
2017-12-23 17:21:39 +00:00
Rafael Espindola ce3b52c186 Pass an InputFile to the InputSection constructor.
This simplifies toRegularSection and reduces the noise in a followup
patch.

llvm-svn: 321240
2017-12-21 02:11:51 +00:00
Rafael Espindola 604032729c Convert a few more InputFiles to references.
We use null files in sections to represent linker created sections,
so ObjFile<ELFT> is never null.

llvm-svn: 321238
2017-12-21 02:03:39 +00:00
Rafael Espindola 5c73c49c9f Detemplate createCommentSection.
It was only templated so it could create a dummy section header that
was immediately parsed back.

llvm-svn: 321235
2017-12-21 01:21:59 +00:00
Rafael Espindola fc29b8dd63 Remove unnecessary this->. NFC.
llvm-svn: 321081
2017-12-19 16:29:02 +00:00
Rafael Espindola f4fb5fd752 Move Repl to SectionBase.
It is currently in InputSectionBase. Only InputSections are used in
ICF, so Repl should be move to InputSection to clear the class
hierarchy or, like this patch does, to SectionBase for convenience.

The convenience of having it on the base class is that we can just
access the replacement without having to first check if it is an
InputSection. It is a bit less code and a bit faster as some of this
code is very hot.

I got up to 1.77% improvement in clang-gdb-index and no regressions
according to lnt.

llvm-svn: 320654
2017-12-13 22:59:23 +00:00
Rafael Espindola b3973eed3c Move Repl check to a symbol method.
Having a SectionBase method check Repl is inconsistent with how we
handle other section information.

For example, if a section is replaced, Sec->Live is false and it is
natural for Sec->getOutputSection() to be null.

It is the symbol that is moved to the replacement section.

llvm-svn: 320599
2017-12-13 17:46:29 +00:00