Commit Graph

265 Commits

Author SHA1 Message Date
Rui Ueyama acb67bcb98 Move a utility function to Strings.cpp.
So that we can use the function from anywhere.

llvm-svn: 284092
2016-10-13 00:13:15 +00:00
Rui Ueyama 5665af836f Fix variable name. NFC.
llvm-svn: 284079
2016-10-12 23:22:59 +00:00
Rui Ueyama 05384080df Support GNU-style ZLIB-compressed input sections.
Previously, we supported only SHF_COMPRESSED sections because it's
new and it's the ELF standard. But there are object files compressed
in the GNU style out there, so we had to support it.

Sections compressed in the GNU style start with ".zdebug_" and
contain different headers than the ELF standard's one. In this
patch, getRawCompressedData is responsible to handle it.

A tricky thing about GNU-style compressed sections is that we have
to rename them when creating output sections. ".zdebug_" prefix
implies the section is compressed. We need to rename ".zdebug_"
".debug" because our output sections are not compressed.
We do that in this patch.

llvm-svn: 284068
2016-10-12 22:36:31 +00:00
Peter Smith 0a259f3b9c [ELF][ARM] Initial implentation of ARM exceptions support
The .ARM.exidx sections contain a table. Each entry has two fields:
- PREL31 offset to the function the table entry describes
- Action to take, either cantunwind, inline unwind, or PREL31 offset to
  .ARM.extab section

The table entries must be sorted in order of the virtual addresses the
first entry of the table describes. Traditionally this is implemented by
the SHF_LINK_ORDER dependency. Instead of implementing this directly we
sort the table entries post relocation. 

The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program
header

Differential revision: https://reviews.llvm.org/D25127

llvm-svn: 283730
2016-10-10 09:39:26 +00:00
Rui Ueyama 8c8ff00b28 Improve comments.
Also use uint64_t instead of uintX_t so that you don't have to
think about two different cases to verify that the code is correct.

llvm-svn: 283585
2016-10-07 19:54:57 +00:00
Rafael Espindola 88b9d66d4a Add () for clarity. NFC.
llvm-svn: 283556
2016-10-07 14:23:28 +00:00
George Rimar 7c213fd17e [ELF] - Check that section alignment is a power of 2.
I found that this check still may be useful in some cases.
At fact since we use uint32_t alignment, then maximum value
that is valid for us is 0x80000000. But some broken files,
for example file from testcase may have greater value.
Because of that offset calculation overflow and crash happens.

Differential revision: https://reviews.llvm.org/D25324

llvm-svn: 283544
2016-10-07 12:27:45 +00:00
Rafael Espindola 5fc2b1d2fe Store the hash in SectionPiece.
This spreads out computing the hash and using it in a hash table. The
speedups are:

firefox
  master 6.811232891
  patch  6.559280249 1.03841162939x faster
chromium
  master 4.369323666
  patch  4.33171853 1.00868134338x faster
chromium fast
  master 1.856679971
  patch  1.850617741 1.00327578725x faster
the gold plugin
  master 0.32917962
  patch  0.325711944 1.01064645023x faster
clang
  master 0.558015452
  patch  0.550284165 1.01404962652x faster
llvm-as
  master 0.032563515
  patch  0.032152077 1.01279662275x faster
the gold plugin fsds
  master 0.356221362
  patch  0.352772162 1.00977741549x faster
clang fsds
  master 0.635096494
  patch  0.627249229 1.01251060127x faster
llvm-as fsds
  master 0.030183188
  patch  0.029889544 1.00982430511x faster
scylla
  master 3.071448906
  patch  2.938484138 1.04524944215x faster

This seems to be because we don't stall as much. When linking firefox
stalled-cycles-frontend goes from 57.56% to 55.55%.

With -O2 the difference is even more significant since we avoid
recomputing the hash. For firefox we go from 9.990295265 to
 9.149627521 seconds (1.09x faster).

llvm-svn: 283367
2016-10-05 19:36:02 +00:00
Rafael Espindola 32aca87bf8 Compact SectionPiece.
It is pretty easy to get the data from the InputSection, so we don't
have to store it.

This opens the way for storing the hash instead.

llvm-svn: 283357
2016-10-05 18:40:00 +00:00
Rafael Espindola 939e9493bf Simplify setting the Live bit in SectionPiece. NFC.
llvm-svn: 283340
2016-10-05 17:02:09 +00:00
George Rimar 422e47a9f5 [ELF] - Do not hang if broken object has option descriptor in .MIPS.options with size of zero.
Previously lld would hang in infinite loop in this case,
patch fixes the issue. Object was found during AFL run.

Differential revision: https://reviews.llvm.org/D25229

llvm-svn: 283208
2016-10-04 10:23:07 +00:00
Simon Atanasyan 3a61cabbb2 [ELF][MIPS] Do not accept non-zero GP0 value for relocatable object only
Follow-up to r282716. Reject input files with non-zero GP0 value only in
case of relocatable object generation. In other case we can handle
arbitrary GP0 value so it does not have a sense to make the restriction
so wide.

llvm-svn: 283194
2016-10-04 08:24:25 +00:00
George Rimar 2c0a7f081a [ELF] - Do not crash on invalid section alignment.
Case was revealed by id_000010,sig_08,src_000000,op_havoc,rep_4 from PR30540.

Out implementation uses uint32 for storing section alignment value,
what seems reasonable, though if value exceeds 32 bits bounds we have
truncation and final value of 0.

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D25082

llvm-svn: 283097
2016-10-03 10:04:38 +00:00
George Rimar f50bafc708 [ELF] - Inlined template argument variable. NFC.
llvm-svn: 282851
2016-09-30 13:46:34 +00:00
Rafael Espindola 2629602f28 Fix another --gc-sections crash.
The missing case was when a merge section was only referenced from
non-alloca sections.

llvm-svn: 282847
2016-09-30 06:48:09 +00:00
Rafael Espindola c1eff79f61 Fix --gc-sections crash.
We would crash when a non-alloca section pointed to a gced part of a
merge section.

That can happen when a C/c++ constant in put in a merge section and
debug info is present.

llvm-svn: 282845
2016-09-30 06:37:29 +00:00
Simon Atanasyan 353fc1e947 [ELF][MIPS] Set GP0 value to zero in case of relocatable object generation
LLD does not update relocations addends when generate a relocatable
object. That is why we should not write a non-zero GP0 value into
the .reginfo and .MIPS.options sections. And we should not accept input
object files with non-zero GP0 value because we cannot handle them
properly.

llvm-svn: 282716
2016-09-29 12:58:48 +00:00
Eugene Leviant d2778848ef Don't GC non-alloc mergeable section pieces
Differential revision: https://reviews.llvm.org/D25033

llvm-svn: 282708
2016-09-29 10:27:10 +00:00
Davide Italiano 03f7005375 [ELF] Resolve weak undefined TLS symbols when no phdr is available.
If we pass --gc-sections to lld and .tbss is not referenced,
the section is reclaimed and lld doesn't create a TLS program header.
R_TLS tries to access the program header -> lld crashes.
Mimic what bfd/gold do in this case and resolve a weak undefined
TLS symbol to the base of the TLS block, i.e. give it a value of zero.

Differential Revision:  https://reviews.llvm.org/D24832

llvm-svn: 282279
2016-09-23 18:47:50 +00:00
Rui Ueyama 2d7fe598f2 Turn a no-op assignment into an assertion.
r279456 guarantees that this condition is always satisfied.

llvm-svn: 281426
2016-09-14 00:09:50 +00:00
Rafael Espindola c7e1e03498 Store an ArrayRef for Data in InputSectionData.
llvm-svn: 281210
2016-09-12 13:13:53 +00:00
Rafael Espindola 54f1614ec1 Revert "Revert "Compact InputSectionData from 64 to 48 bytes. NFC.""
This reverts commit r281096.

The previous link errors should be fixed by r281208.

llvm-svn: 281209
2016-09-12 13:06:10 +00:00
Rafael Espindola 78fe670994 Revert "Compact InputSectionData from 64 to 48 bytes. NFC."
This reverts commit r281084.

The link was failing on some bots. No idea why. I will try to
reproduce it on Monday.

llvm-svn: 281096
2016-09-09 21:20:30 +00:00
Rafael Espindola 82621dcb10 Compact InputSectionData from 64 to 48 bytes. NFC.
llvm-svn: 281084
2016-09-09 19:42:11 +00:00
Rafael Espindola 042a3f209b Compute section names only once.
This simplifies error handling as there is now only one place in the
code that needs to consider the possibility that the name is
corrupted. Before we would do it in every access.

llvm-svn: 280937
2016-09-08 14:06:08 +00:00
Rafael Espindola 16853bb00f Pack InputSectionData from 72 to 64 bytes. NFC.
llvm-svn: 280925
2016-09-08 12:33:41 +00:00
Rafael Espindola 664c6522fa Delete dead field. NFC.
llvm-svn: 280856
2016-09-07 20:37:34 +00:00
Eugene Leviant 97403d15ee Eliminate LayoutInputSection class
Previously we used LayoutInputSection class to correctly assign
symbols defined in linker script. This patch removes it and uses
pointer to preceding input section in SymbolAssignment class instead.

Differential revision: https://reviews.llvm.org/D23661

llvm-svn: 280348
2016-09-01 09:55:57 +00:00
Rafael Espindola 79202c378f Fix the implementation of R_386_GOTPC and R_386_GOTOFF.
They were both pointing to the start of the got, not the end.

Fixes pr28924.

llvm-svn: 280310
2016-08-31 23:24:11 +00:00
Rafael Espindola 7f4f9cd546 Use getSize to find the size of a section. NFC.
llvm-svn: 280305
2016-08-31 23:01:13 +00:00
Rafael Espindola e7553e4eac Delete unnecessary template.
llvm-svn: 280237
2016-08-31 13:28:33 +00:00
George Rimar 3e6833b4b2 [ELF] - Fix for PR28976 - Corrupted section contents when using linker scripts
This is fix for PR28976.

Problem was that in scanRelocs, we computed relocation offset too early 
for case when linkerscript was used. Patch fixes the issue 
delaying the calculation.

Differential revision: https://reviews.llvm.org/D23655

llvm-svn: 279264
2016-08-19 15:46:28 +00:00
Simon Atanasyan 85c6b44817 [ELF][MIPS] Support .MIPS.abiflags section
This section supersedes .reginfo and .MIPS.options sections. But for now
we have to support all three sections for ABI transition period.

llvm-svn: 278482
2016-08-12 06:28:49 +00:00
Eugene Leviant ceabe80e97 [ELF] Symbol assignment within output section description
llvm-svn: 278322
2016-08-11 07:56:43 +00:00
Rui Ueyama d6bd1371fc Include filenames and section names to error messages.
llvm-svn: 277566
2016-08-03 04:39:42 +00:00
George Rimar 7b360f2441 [ELF] - Fix: do not ignore relocations addends when using lld -r
Previously addends were ignored. This is PR28779.
Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D23011

llvm-svn: 277432
2016-08-02 08:49:57 +00:00
Rui Ueyama 0778490428 Remove DefinedCommon::Section.
Since CommonInputSection is a singleton class, we don't need
to store pointers to all DefinedCommon symbols.

llvm-svn: 277410
2016-08-02 01:35:13 +00:00
Rui Ueyama 09d4f177fc Remove dependency to SymbolTable from CommonInputSection.
llvm-svn: 277103
2016-07-29 03:39:44 +00:00
Rui Ueyama ad10c3d8d4 Make CommonInputSection singleton class.
All other singleton instances are accessible globally.
CommonInputSection shouldn't be an exception.

Differential Revision: https://reviews.llvm.org/D22935

llvm-svn: 277034
2016-07-28 21:05:04 +00:00
Eugene Leviant 3e6b027705 [ELF] Allows setting section for common symbols in linker script
llvm-svn: 277023
2016-07-28 19:24:13 +00:00
Rafael Espindola 2deeb6093d Fix PR28575.
Not all relocations from a .eh_frame that point to an executable
section should be ignored. In particular, the relocation finding the
personality function should not.

This is a reduction from trying to bootstrap a static lld on linux.

llvm-svn: 276329
2016-07-21 20:18:30 +00:00
Rafael Espindola 6eae9f2c67 Delete SplitInputSection.
This opens the way for having a different Piece type for EhInputSection.

llvm-svn: 276275
2016-07-21 13:32:37 +00:00
Rafael Espindola 2197311c31 Delete EhInputSection::getOffset.
We no longer need it for relocations in .eh_frame.

The only relocations that point to .eh_frame are the ones trying to
find the output .eh_frame.

This actually fixes a bug in the symbol value code. It was not
handling -1 as an indicator for a piece not being included in the
output.

llvm-svn: 276175
2016-07-20 20:19:58 +00:00
Rafael Espindola 0f7cedaa1e Create thunks before regular relocation scan.
We will need to do something like this to support range extension
thunks since that process is iterative.

Doing this also has the advantage that when doing the regular
relocation scan the offset in the output section is known and we can
just store that. This reduces the number of times we have to run
getOffset and I think will allow a more specialized .eh_frame
representation.

By itself this is already a performance win.

firefox
  master 7.295045737
  patch  7.209466989 0.98826892235
chromium
  master 4.531254468
  patch  4.509221804 0.995137623774
chromium fast
  master 1.836928973
  patch  1.823805241 0.992855612714
the gold plugin
  master 0.379768791
  patch  0.380043405 1.00072310839
clang
  master 0.642698284
  patch  0.642215663 0.999249070657
llvm-as
  master 0.036665467
  patch  0.036456225 0.994293213284
the gold plugin fsds
  master 0.40395817
  patch  0.404384555 1.0010555177
clang fsds
  master 0.722045545
  patch  0.720946135 0.998477367518
llvm-as fsds
  master 0.03292646
  patch  0.032759965 0.994943428477
scylla
  master 3.427376378
  patch  3.368316181 0.98276810292

llvm-svn: 276146
2016-07-20 17:58:07 +00:00
Eugene Leviant e63d81bd05 [ELF] Create output sections in LinkerScript class
llvm-svn: 276121
2016-07-20 14:43:20 +00:00
George Rimar 5d53d1f42c [ELF] - Make few members of Writer to be global and export them for reuse
Creating sections on linkerscript side requires some methods
that can be reused if are exported from writer.

Patch implements that change.

Differential revision: http://reviews.llvm.org/D20104

llvm-svn: 275162
2016-07-12 08:50:42 +00:00
Rui Ueyama ec1b80fd11 Remove unused parameters.
llvm-svn: 275153
2016-07-12 03:49:41 +00:00
Peter Smith fb05cd997c Recommit R274836 Add Thunk support framework for ARM and Mips
The TinyPtrVector of const Thunk<ELFT>* in InputSections.h can cause 
build failures on certain compiler/library combinations when Thunk<ELFT> 
is not a complete type or is an abstract class. Fixed by making Thunk<ELFT>
non Abstract.

type or is an abstract class 

llvm-svn: 274863
2016-07-08 16:10:27 +00:00
Peter Smith eeb827447e Revert R274836 Add Thunk support framework for ARM and Mips
This seems to be causing a buildbot failure on lld-x86_64-freebsd. Will
reproduce locally and fix. 

llvm-svn: 274841
2016-07-08 12:25:50 +00:00
Peter Smith de01b98a26 Add Thunk support framework for ARM and Mips
Generalise the Mips LA25 Thunk code and implement ARM and Thumb
    interworking Thunks.
    
    - Introduce a new module Thunks.cpp to store the Target Specific Thunk
      implementations.
    - DefinedRegular and Shared have a ThunkData field to record Thunk.
    - A Target can have more than one type of Thunk.
    - Support PC-relative calls to Thunks.
    - Support Thunks to PLT entries.
    - Existing Mips LA25 Thunk code integrated.
    - Support for ARMv7A interworking Thunks.
    
    Limitations:
    - Only one Thunk per SymbolBody, this is sufficient for all currently
      implemented Thunks.
    - ARM thunks assume presence of V6T2 MOVT and MOVW instructions.

    Differential revision: http://reviews.llvm.org/D21891

llvm-svn: 274836
2016-07-08 11:13:40 +00:00