Commit Graph

488 Commits

Author SHA1 Message Date
Rui Ueyama da805c4800 Use uint16_t instead of size_t for symbol version ID.
Because it is uint16_t in the ELF spec. Using size_t was confusing.

llvm-svn: 287198
2016-11-17 03:39:21 +00:00
Rui Ueyama aade0e29ad Add single quotes to a warning message for consistency.
llvm-svn: 287197
2016-11-17 03:32:41 +00:00
Rui Ueyama 77d917de57 Simplify handleAnonymousVersion even more.
We used to create a vector contantaining all version definitions
with wildcards because doing that was efficient. All patterns were
compiled to a regexp and matched against symbol names. Because
a regexp can be converted to a DFA, matching against union of patterns
is as cheap as matching against one patter.

We are no longer converting them to regexp. Our own glob pattern
handler doesn't do such optimization. Therefore, creating a vector
no longer makes sense.

llvm-svn: 287196
2016-11-17 03:19:34 +00:00
Rui Ueyama 4162baa4bb Simplify. NFC.
llvm-svn: 287192
2016-11-17 02:16:06 +00:00
Rui Ueyama 94bcfae26d Split scanVersionScript. NFC.
llvm-svn: 287191
2016-11-17 02:09:42 +00:00
George Rimar 17c65af82f [ELF] - Separate locals list from versions.
This change separates all versioned locals to be a separate list in config,
that was suggested by Rafael and simplifies the logic a bit.

Differential revision: https://reviews.llvm.org/D26754

llvm-svn: 287132
2016-11-16 18:46:23 +00:00
Rafael Espindola 95eae57d78 Don't error if __tls_get_addr is defined.
Turns out some systems do define it. Not producing an error in this
case matches gold and bfd.

llvm-svn: 287125
2016-11-16 18:01:41 +00:00
George Rimar e0fc24210d [ELF] - Added support for extern "c++" local symbols in version script.
Previously we did not support them,
patch implements this functionality

Differential revision: https://reviews.llvm.org/D26604

llvm-svn: 287124
2016-11-16 17:59:10 +00:00
Eugene Leviant afaa934304 [ELF] Add Section() to expression object
This allows making symbols containing ADDR(section) synthetic,
and defining synthetic symbols outside SECTIONS block.

Differential revision: https://reviews.llvm.org/D25441

llvm-svn: 287090
2016-11-16 09:49:39 +00:00
Rui Ueyama 8249214299 Refactor symbol version assignmnt code.
The code to handle symbol versions is getting tricky and hard to
understand, so it is probably time to simplify it. This patch does
the following.

 - Add `DemangledSyms` variable to SymbolTable so that we don't
   need to pass it around to findDemangled.
 - Define `initDemangledSyms` to initialize the variable lazily.
 - hasExternCpp is removed because we no longer have to initialize
   the map eagerly.
 - scanScriptVersion is split.
 - Comments are updated.

llvm-svn: 287002
2016-11-15 18:41:52 +00:00
Rui Ueyama baf7ee3c5e Rename variables of type SymbolVersion.
In this file, `sym` was used for both SymbolBody and SymbolVersion
although the two are completely different.

llvm-svn: 286992
2016-11-15 17:51:09 +00:00
George Rimar 463984d4bf [ELF] - Better diagnostic for relative relocation to an absolute value error.
Patch adds a filename to that error message.

I faced next error when debugged one of FreeBSD port:
error: relocation R_X86_64_PLT32 cannot refer to absolute symbol __tls_get_addr

error message was poor and this patch improves it to show the locations 
of symbol declaration and using.

Differential revision: https://reviews.llvm.org/D26508

llvm-svn: 286940
2016-11-15 08:07:14 +00:00
George Rimar 92ca6f4b7d [ELF] - Fix mistype. NFC.
llvm-svn: 286801
2016-11-14 09:56:35 +00:00
George Rimar bb6c01e7c3 [ELF] - Add support for locals list in version script.
Previously we did not support anything except "local: *", patch changes that.

Actually GNU rules of proccessing wildcards are more complex than that (http://www.airs.com/blog/archives/300):
There are 2 iteration for wildcards, at first iteration "*" wildcards are ignored and handled at second iteration.

Since we previously decided not to implement such complex rules,
I suggest solution that is implemented in this patch. So for "local: *" case nothing changes,
but if we have wildcarded locals,
they are processed before wildcarded globals. 

This should fix several FreeBSD ports, one of them is jpeg-turbo-1.5.1 and
currently blocks about 5k of ports.

Differential revision: https://reviews.llvm.org/D26395

llvm-svn: 286713
2016-11-12 07:04:15 +00:00
Teresa Johnson 1e390897ba Mirror the llvm changes that split Bitcode/ReaderWriter.h
The change in D26502 splits ReaderWriter.h, which contains the APIs
into both the BitReader and BitWriter libraries, into BitcodeReader.h
and BitcodeWriter.h.

Change lld uses to the appropriate split header, removing it
completely in one case where it wasn't needed.

llvm-svn: 286568
2016-11-11 05:35:22 +00:00
Rui Ueyama 1bdaf3e30c Remove an overloaded function to simplify.
This version of addRegular is almost identical to the other except
it lacked "size" parameter.

llvm-svn: 286416
2016-11-09 23:37:40 +00:00
Rafael Espindola e08e78df6d Make OutputSectionBase a class instead of class template.
The disadvantage is that we use uint64_t instad of uint32_t for some
value in 32 bit files. The advantage is a substantially simpler code,
faster builds and less code duplication.

llvm-svn: 286414
2016-11-09 23:23:45 +00:00
Rui Ueyama edc183e437 Simplify getLocation() function.
All tests pass without the first parameter, so I guess we don't need it.

Differential Revision: https://reviews.llvm.org/D26411

llvm-svn: 286287
2016-11-08 20:30:19 +00:00
Rui Ueyama 9c5a69d2ac Rename a function to avoid function overloading. NFC.
llvm-svn: 286282
2016-11-08 20:02:23 +00:00
Eugene Leviant 825e538559 [ELF] Better error reporting for duplicate symbol
Differential revision: https://reviews.llvm.org/D26397

llvm-svn: 286244
2016-11-08 16:26:32 +00:00
Simon Atanasyan 9e0297b8bc [ELF][MIPS] N32 ABI support
In short the patch introduces support for linking object file conform
MIPS N32 ABI [1]. This ABI is similar to N64 ABI but uses 32-bit
pointer size.

The most non-trivial requirement of this ABI is one more relocation
packing format. N64 ABI puts multiple relocation type into the single
relocation record. The N32 ABI uses series of successive relocations
with the same offset for this purpose. In this patch, new function
`mergeMipsN32RelTypes` handle this case and "convert" N32 relocation to
the N64 relocation so the rest of the code keep unchanged.

For now, linker does not support series of relocations applied to sections
without SHF_ALLOC bit. Probably later I will add the support or insert
some sort of assert into the `relocateNonAlloc` routine to catch this
case.

[1] ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/MIPS-N32-ABI-Handbook.pdf

Differential revision: https://reviews.llvm.org/D26298

llvm-svn: 286052
2016-11-05 22:58:01 +00:00
Rui Ueyama f91282e1cf Add [<chars>] to the glob matcher to eliminate use of llvm::Regex.
Previously, it didn't support the character class, so we couldn't
eliminate the use fo llvm::Regex. Now that it is supported, we
can remove compileGlobPattern, which converts a glob pattern to
a regex.

This patch contains optimization for exact/prefix/suffix matches.

Differential Revision: https://reviews.llvm.org/D26284

llvm-svn: 285949
2016-11-03 17:57:38 +00:00
George Rimar bcba39ab9c [ELF] - Check that .dynsym is present in DSO if SHT_GNU_versym section is.
When we have SHT_GNU_versym section, it is should be associated with symbol table
section. Usually (and in out implementation) it is .dynsym.
In case when .dynsym is absent (due to broken object for example), 
lld crashes in parseVerdefs() when accesses null pointer:

Versym = reinterpret_cast<const Elf_Versym *>(this->ELFObj.base() +
                                              VersymSec->sh_offset) +
         this->Symtab->sh_info;

DIfferential revision: https://reviews.llvm.org/D25553

llvm-svn: 285796
2016-11-02 10:16:25 +00:00
Rui Ueyama 55518e7dd8 Consolidate BumpPtrAllocators.
Previously, we have a lot of BumpPtrAllocators, but all these
allocators virtually have the same lifetime because they are
not freed until the linker finishes its job. This patch aggregates
them into a single allocator.

Differential revision: https://reviews.llvm.org/D26042

llvm-svn: 285452
2016-10-28 20:57:25 +00:00
Rafael Espindola 093abab817 Don't create a dummy ELF to process a binary file.
Now that it is easy to create input section and symbols, this is
simple.

llvm-svn: 285322
2016-10-27 17:45:40 +00:00
Rafael Espindola 5ceeb60c6e Have on addRegular forward to another. NFC.
Another step in making it easier to create symbols without an ELf_Sym.

llvm-svn: 285241
2016-10-26 20:57:14 +00:00
Rui Ueyama 8fcc3afdd1 Move a helper function that doesn't depend on a class out of the class.
llvm-svn: 285220
2016-10-26 18:28:08 +00:00
Rui Ueyama 5ce977ccd0 Define a helper function to demangle symbols.
llvm-svn: 285219
2016-10-26 18:28:06 +00:00
Rafael Espindola 5da1d88492 Reduce the number of allocators.
We used to have one allocator per file, which reduces the advantage of
using an allocator in the first place.

This is a small speed up is most cases. The largest speedup was in
1.014X in chromium no-gc. The largest slowdown was scylla at 1.003X.

llvm-svn: 285205
2016-10-26 15:34:24 +00:00
Rafael Espindola 8b2c8536e5 Use a CachedHashString for comdats too.
We were already using it in the larger sets/maps. This provides about
1% speedup in linking xul and chromium.

llvm-svn: 284862
2016-10-21 19:49:42 +00:00
George Rimar a4c7e74d4b [ELF] - Applied clang format. NFC.
llvm-svn: 284705
2016-10-20 08:36:42 +00:00
Justin Lebar 3c11e93831 Use CachedHashStringRef instead of CachedHash<StringRef>.
Summary:
This uses one less word on 64-bit platforms, so should be a strict
improvement.  This change also lets us get rid of llvm::CachedHash.

Reviewers: rafael, timshen

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25646

llvm-svn: 284502
2016-10-18 17:50:36 +00:00
Davide Italiano bcdd6c60a0 [ThinLTO] Avoid archive member collisions.
This fixes PR30665.

Differential Revision:  https://reviews.llvm.org/D25495

llvm-svn: 284034
2016-10-12 19:35:54 +00:00
Rui Ueyama d31e13f287 Rename warning -> warn.
It's better because it's a verb.

llvm-svn: 282763
2016-09-29 21:00:23 +00:00
Davide Italiano 786d8e33db [ELF/LTO] Switch to the new resolution-based API.
Differential Revision:  https://reviews.llvm.org/D24492

llvm-svn: 282656
2016-09-29 00:40:08 +00:00
George Rimar 31c25ae90a Recommit r281318 "[ELF] - Versionscript: support mangled symbols with the same name."
Previouly bot was failing:
http://lab.llvm.org:8011/builders/clang-with-lto-ubuntu/builds/413/steps/test-stage1-compiler/logs/stdio
Fixed possible segfault, so commit should bix the buildbot.

Initial commit message:

This is PR30312. Info from bug page:

Both of these symbols demangle to abc::abc():
_ZN3abcC1Ev
_ZN3abcC2Ev
(These would be abc's complete object constructor and base object constructor, respectively.)
however with "abc::abc()" in the version script only one of the two receives the symbol version.

Patch fixes that.
It uses testcase created by Ed Maste (D24306).

Differential revision: https://reviews.llvm.org/D24336

llvm-svn: 281605
2016-09-15 12:44:38 +00:00
Rui Ueyama 38dbd3eea9 Simplify InputFile ownership management.
Previously, all input files were owned by the symbol table.
Files were created at various places, such as the Driver, the lazy
symbols, or the bitcode compiler, and the ownership of new files
was transferred to the symbol table using std::unique_ptr.
All input files were then free'd when the symbol table is freed
which is on program exit.

I think we don't have to transfer ownership just to free all
instance at once on exit.

In this patch, all instances are automatically collected to a
vector and freed on exit. In this way, we no longer have to
use std::unique_ptr.

Differential Revision: https://reviews.llvm.org/D24493

llvm-svn: 281425
2016-09-14 00:05:51 +00:00
George Rimar 84ba4ae11d revert: [ELF] - Versionscript: support mangled symbols with the same name.
Something broked BBots:
281318 failed on step 9:
http://lab.llvm.org:8011/builders/clang-with-lto-ubuntu/builds/413

r281317 built step 9 green:
http://lab.llvm.org:8011/builders/clang-with-lto-ubuntu/builds/415

Initial revision commits were:
This is PR30312. Info from bug page:

Both of these symbols demangle to abc::abc():
_ZN3abcC1Ev
_ZN3abcC2Ev
(These would be abc's complete object constructor and base object constructor, respectively.)
however with "abc::abc()" in the version script only one of the two receives the symbol version.

Patch fixes that.
It uses testcase created by Ed Maste (D24306).

Differential revision: https://reviews.llvm.org/D24336

llvm-svn: 281411
2016-09-13 22:26:12 +00:00
Rui Ueyama ea26504c19 Split scanVersionScript. NFC.
llvm-svn: 281393
2016-09-13 20:51:30 +00:00
Rui Ueyama fbde710497 Add comments.
llvm-svn: 281388
2016-09-13 20:41:06 +00:00
George Rimar e2051efcbe [ELF] - Versionscript: support mangled symbols with the same name.
This is PR30312. Info from bug page:

Both of these symbols demangle to abc::abc():
_ZN3abcC1Ev
_ZN3abcC2Ev
(These would be abc's complete object constructor and base object constructor, respectively.)
however with "abc::abc()" in the version script only one of the two receives the symbol version.

Patch fixes that.
It uses testcase created by Ed Maste (D24306).

Differential revision: https://reviews.llvm.org/D24336

llvm-svn: 281318
2016-09-13 10:45:39 +00:00
Michael J. Spencer 0cb8a70adc [ELF] Fix memory leak in BinaryFile handling.
llvm-svn: 281129
2016-09-10 01:42:43 +00:00
Michael J. Spencer a9424f39c4 [ELF] Add support for -b binary
Implemented by building an ELF file in memory.

elf, default, and binary match gold behavior.

Differential Revision: https://reviews.llvm.org/D24060

llvm-svn: 281108
2016-09-09 22:08:04 +00:00
George Rimar cd574a5e46 Recommit [ELF] - Versionscript: do not treat non-wildcarded names as wildcards.
Fixed code that was not checked before on windows for me, because of testcases that are
disabled on that platform atm.

Inital commit message:
"[ELF] - Versionscript: do not treat non-wildcarded names as wildcards."
Previously we incorrectly handled cases when symbol name in extern c++ tag
was enclosed in quotes. Next case was treated as wildcard:

GLIBCXX_3.4 {                                                                   
    extern "C++" {  
    "aaa*"
   }
But it should have not. Quotes around aaa here means that we should have do exact
name matching.
That is PR30268 which has name with pointer is interpreted as wildcard by lld:

extern "C++" {                                                              
    "operator delete[](void*)";

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D24229

llvm-svn: 281049
2016-09-09 14:35:36 +00:00
George Rimar 6368525eea Revert r281045, it broke BB.
Broken BB:
http://lab.llvm.org:8011/builders/lld-x86_64-darwin13/builds/27211

llvm-svn: 281046
2016-09-09 14:16:00 +00:00
George Rimar b5e77c47fb Recommit [ELF] - Versionscript: do not treat non-wildcarded names as wildcards.
Fixed code that was not checked by testcases that are disabled on windows.

Inital commit message:
"[ELF] - Versionscript: do not treat non-wildcarded names as wildcards."
Previously we incorrectly handled cases when symbol name in extern c++ tag
was enclosed in quotes. Next case was treated as wildcard:

GLIBCXX_3.4 {                                                                   
    extern "C++" {  
    "aaa*"
   }
But it should have not. Quotes around aaa here means that we should have do exact
name matching.
That is PR30268 which has name with pointer is interpreted as wildcard by lld:

extern "C++" {                                                              
    "operator delete[](void*)";

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D24229

llvm-svn: 281045
2016-09-09 13:58:07 +00:00
George Rimar 08b1862caf [ELF] - Revert r281038 to see if that unbreaks build bot.
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/19703

llvm-svn: 281041
2016-09-09 12:56:55 +00:00
George Rimar d220384376 [ELF] - Versionscript: do not treat non-wildcarded names as wildcards.
Previously we incorrectly handled cases when symbol name in extern c++ tag
was enclosed in quotes. Next case was treated as wildcard:

GLIBCXX_3.4 {                                                                   
    extern "C++" {  
    "aaa*"
   }
But it should have not. Quotes around aaa here means that we should have do exact
name matching.
That is PR30268 which has name with pointer is interpreted as wildcard by lld:

extern "C++" {                                                              
    "operator delete[](void*)";

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D24229

llvm-svn: 281038
2016-09-09 12:22:28 +00:00
Rafael Espindola 868fc9279e Handle globs in global symbol names.
Fixes pr28775.

llvm-svn: 280947
2016-09-08 14:50:55 +00:00
Rui Ueyama dad2b88c7d Update comments.
llvm-svn: 280548
2016-09-02 22:15:08 +00:00
George Rimar c91930a17f [ELF] - Use std::regex instead of hand written logic in elf::globMatch()
Use std::regex instead of hand written matcher.

Patch based on code and ideas of Rui Ueyama.

Differential revision: https://reviews.llvm.org/D23829

llvm-svn: 280544
2016-09-02 21:17:20 +00:00
Rafael Espindola 0509876f3f Remove redundant argument. NFC.
llvm-svn: 280243
2016-08-31 13:49:23 +00:00
Rafael Espindola 8db87291ef Internalize common variables.
Before this lld was always creating common symbols itself. It worked,
but prevented them from being internalized when possible.

Now it preserves common symbols is the bitcode and they are internalized.

Fixes pr30184.

llvm-svn: 280242
2016-08-31 13:42:08 +00:00
Rafael Espindola e7553e4eac Delete unnecessary template.
llvm-svn: 280237
2016-08-31 13:28:33 +00:00
Rafael Espindola a6c9744a6c Delete DefinedBitcode.
Given that we almost always want to handle it as DefinedRegular, just
use DefinedRegular.

llvm-svn: 280226
2016-08-31 12:30:34 +00:00
Rafael Espindola cceb92a075 Pass Binding instead of IsWeak to addBitcode.
We were computing the binding on both the caller and callee.

llvm-svn: 280156
2016-08-30 20:53:26 +00:00
Davide Italiano 35af5b3d21 [LTO] Fix the logic for dropping unnamed_addr.
Differential Revision:  https://reviews.llvm.org/D24037

llvm-svn: 280144
2016-08-30 20:15:03 +00:00
George Rimar 7af6452927 [ELF] - Use early return. NFC.
This addresses forgotten review comment for r280067:
"[ELF] - Versionscript: support wildcards for extern "c++" tag."

llvm-svn: 280068
2016-08-30 09:39:36 +00:00
George Rimar 397cd87a69 [ELF] - Versionscript: support wildcards for extern "c++" tag.
Previously for extern keyword only names in quotes (exact match) was supported.
Patch adds support for wildcards, so next scripts can be handled properly:

LIBSAMPLE_1.0 {
   global:            
     extern "C++" {  
       foo*;   
   };                  
 };

Differential revision: https://reviews.llvm.org/D23794

llvm-svn: 280067
2016-08-30 09:35:03 +00:00
George Rimar c3ec9d0cbf [ELF] - Cleanup of scanVersionScript(): do not change local Demangled variable. NFC.
llvm-svn: 280066
2016-08-30 09:29:37 +00:00
George Rimar e1937bb524 [ELF] - Give automatically generated __start_* and __stop_* symbols default visibility.
This patch is opposite to D19024, which made this symbols to be hidden by default.

Unfortunately FreeBSD loader wants to see
start_set_modmetadata_set/stop_set_modmetadata_set in the dynamic symbol table. 
They were not placed there because had hidden visibility.

Patch makes them to have default visibility again.

Differential revision: https://reviews.llvm.org/D23552

llvm-svn: 279262
2016-08-19 15:36:32 +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
Rui Ueyama dace838138 Simplify symbol version handling.
r275711 for "speedng up symbol version handling" was committed
by misunderstanding; the benchmark number was measured with
a debug build. The number with a release build didn't actually change.
This patch removes false optimizations added in that patch.

llvm-svn: 276267
2016-07-21 13:13:21 +00:00
George Rimar b084125dbf [ELF] - Fixed integral constant overflow warning under MSVS 2015. NFC.
Under MSVS 2015 I observed integral constant overflow warning when aggregate initialization was used
to init the bit field. Patch fixes that.

llvm-svn: 276118
2016-07-20 14:26:48 +00:00
Rui Ueyama e33579072d Remove SymbolBody::PlaceholderKind.
In the last patch for --trace-symbol, I introduced a new symbol type
PlaceholderKind and store it to SymVector storage. It made all code
that iterates over SymVector to recognize and skip PlaceholderKind
symbols. I found that that's annoying.

In this patch, I removed PlaceholderKind and stop storing them to SymVector.
Now the information whether a symbol is being watched by --trace-symbol
is stored to the Symtab hash table.

llvm-svn: 275747
2016-07-18 01:35:00 +00:00
Rui Ueyama d6328526ba Iterate over SymVector instead of Symtab hash table.
SymVector contains all symbols, so we can iterate either Symtab or SymVector
to visit all symbols. Iterating over SymVector makes the next change for
--trace-symbol possible.

llvm-svn: 275746
2016-07-18 01:34:57 +00:00
Rui Ueyama 69c778c084 Implement almost-zero-cost --trace-symbol.
--trace-symbol is a command line option to watch a symbol.
Previosly, we looked up a hash table for a new symbol if the
option is given. Any code that looks up a hash table for each
symbol is expensive because the linker handles a lot of symbols.
In our design, we look up a hash table strictly only once
for a symbol, so --trace-symbol was an exception.

This patch improves efficiency of the option by merging the
hash table into the symbol table.

Instead of looking up a separate hash table with a string,
this patch sets `Traced` flag to symbols specified by --trace-symbol.
So, if you insert a symbol and get a symbol with `Traced` flag on,
you know that you need to print out a log message for the symbol.
This is nearly zero cost.

llvm-svn: 275716
2016-07-17 17:50:09 +00:00
Rui Ueyama 2a7c1c1507 Print out file names for common symbols for --trace-symbol.
Previously, there was no way to get a file name for a DefinedCommon
symbol. This patch adds it.

llvm-svn: 275712
2016-07-17 17:36:22 +00:00
Rui Ueyama 663b8c2769 Handle versioned symbols efficiently.
Versions can be assigned to symbols in two different ways.
One is the usual version scripts, and the other is special
symbol suffix '@'. If a symbol contains '@', the string after
that is considered to specify a version name.

Previously, we look for '@' for all symbols.

Anything that works on every symbol can be expensive because
the linker has to handle a lot of symbols. The search for '@'
was not an exception.

In this patch, I made two optimizations.

The first optimization is to handle '@' only when at least one
version is defined. If no versions are defined, no versions can
be assigned to any symbols, so it's waste of time to search for '@'.

The second optimization is to scan only suffixes of symbol names
instead of entire symbol names. Symbol names can be very long, but
symbol versions are usually short, so scanning entire symbol names
is waste of time, too.

There are some error cases which we no longer be able to detect
with this patch. I don't think it's a major drawback because they
are minor errors. Speed is more important.

This change improves LLD with debug info self-link time from
6.6993 seconds to 6.3426 seconds (or -5.3%).

Differential Revision: https://reviews.llvm.org/D22433

llvm-svn: 275711
2016-07-17 17:23:17 +00:00
Rui Ueyama 434b56179e Add a pointer to a source file to SymbolBody.
Previously, each subclass of SymbolBody had a pointer to a source
file from which it was created. So, there was no single way to get
a source file for a symbol. We had getSourceFile<ELFT>(), but the
function was a bit inconvenient as it's a template.

This patch makes SymbolBody have a pointer to a source file.
If a symbol is not created from a file, the pointer has a nullptr.

llvm-svn: 275701
2016-07-17 03:11:46 +00:00
Rui Ueyama 818bb2f8dc Remove redundant namespace specifiers.
llvm-svn: 275694
2016-07-16 18:55:47 +00:00
Rui Ueyama 962b277d2d Resurrect code that was lost in conflicting commits.
llvm-svn: 275693
2016-07-16 18:45:25 +00:00
George Rimar 50dcece2a0 Recommit r275257 "[ELF] - Implement extern "c++" version script tag"
BSD toolchain contains a bug:
https://sourceforge.net/p/elftoolchain/tickets/491/

In short demangler works differently, fix was to update the testcase.
It should fix the FreeBSD bot failture:
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/19432/steps/test_lld/logs/stdio

Original commit message was:
[ELF] - Implement extern "c++" version script tag

Patch implements 'extern' version script tag.
Currently only values in quotes(") are supported.

Matching of externs is performed in the same pass as exact match of globals.

Differential revision: http://reviews.llvm.org/D21930

llvm-svn: 275682
2016-07-16 12:26:39 +00:00
Rui Ueyama af469d47e9 Rename SymbolVersions VersionDefinitions.
SymbolVersions sounds like it had versions for a symbol, so rename it.

llvm-svn: 275674
2016-07-16 04:09:27 +00:00
Rui Ueyama bc94dd9b28 Rename Version VersionDefinition.
The identifier `Version` was used too often in the code to handle
symbol versions. The struct that contains version definitions is
named `Version`. Local variables for version ID are named `Version`.
Local varaible for version string are named `Version`.

This patch give them different names.

llvm-svn: 275673
2016-07-16 04:02:00 +00:00
Rui Ueyama c9b4c073b2 Simplify. NFC.
llvm-svn: 275670
2016-07-16 03:12:16 +00:00
Rui Ueyama 2506866ff6 Simplify default symbol version management. NFC.
llvm-svn: 275669
2016-07-16 03:08:26 +00:00
George Rimar dd64bb38bd Reverted r275257 "[ELF] - Implement extern "c++" version script tag"
It broke build bots:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/8204
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/19432

llvm-svn: 275258
2016-07-13 08:19:04 +00:00
George Rimar e05103ea11 [ELF] - Implement extern "c++" version script tag
Patch implements 'extern' version script tag.
Currently only values in quotes(") are supported.

Matching of externs is performed in the same pass as exact match of globals.

Differential revision: http://reviews.llvm.org/D21930

llvm-svn: 275257
2016-07-13 07:46:00 +00:00
George Rimar 7899d48dff [ELF] - Add Id field to Version struct.
That helps to avoid expressions like I + 2 in code
that assigns version number to symbols.

Change was suggested by Rui Ueyama.

Differential revision: http://reviews.llvm.org/D22086

llvm-svn: 275159
2016-07-12 07:44:40 +00:00
George Rimar c61bcd80af [ELF] - Do not error out when version declaration not found when building executable.
When building executable usually version script is absent.
Before this patch error was shown in the case when
symbol name contained version and there was no script to match it.
  Instead of error out patch allows
to create new version declaration in this case and use it.
gnu linkers do the same.

That is PR28359.

Differential revision: http://reviews.llvm.org/D21890

llvm-svn: 274828
2016-07-08 06:47:28 +00:00
Rui Ueyama f4d9338dfb Move demangle() from Symbols.cpp to Strings.cpp.
Symbols.cpp contains functions to handle ELF symbols.
demangle() function is essentially a function to work on a
string rather than on an ELF symbol. So Strings.cpp is a
better place to put that function.

This change also make demangle to demangle symbols unconditionally.
Previously, it demangled symbols only when Config->Demangle is true.

llvm-svn: 274804
2016-07-07 23:04:15 +00:00
George Rimar f73a25812f [ELF] - Fixed incorrect logic of version assignments when mixing wildcards with values matching.
Previously we had incorrect logic here. Imagine we would have the next script:

LIBSAMPLE_1.0
{
  global:
   a_2;
 local:
  *;
};

LIBSAMPLE_2.0
{
  global:
   a*;
};
According to previous logic it would assign version 1 to a_2 and then
would try to reassign it to version 2 because of applying wildcard a*.
And show a warning about that.

Generally Ian Lance Tailor wrote about next rules that should be applied:
(http://www.airs.com/blog/archives/300)

Here are the current rules for gold:

"If there is an exact match for the mangled name, we use it. If there is more than one exact match, we give a warning, and we use the first tag in the script which matches. If a symbol has an exact match as both global and local for the same version tag, we give an error.
Otherwise, we look for an extern C++ or an extern Java exact match. If we find an exact match, we use it. If there is more than one exact match, we give a warning, and we use the first tag in the script which matches. If a symbol has an exact match as both global and local for the same version tag, we give an error.
Otherwise, we look through the wildcard patterns, ignoring “*” patterns. We look through the version tags in reverse order. For each version tag, we look through the global patterns and then the local patterns. We use the first match we find (i.e., the last matching version tag in the file).
Otherwise, we use the “*” pattern if there is one. We give a warning if there are multiple “*” patterns."

Patch makes wildcard matching to be in revered order and to follow after the regular naming matching.

Differential revision: http://reviews.llvm.org/D21894

llvm-svn: 274739
2016-07-07 07:45:27 +00:00
George Rimar dbbf60e590 [ELF] - Check the input bitcode files for compatibility.
Previously BC files were not checked for the same platform etc,
That lead to confusing error "Invalid section header entry size (e_shentsize) in ELF header" when
mixing files for different architectures.

Patch fixes PR28324.

Differential revision: http://reviews.llvm.org/D21832

llvm-svn: 274113
2016-06-29 09:46:00 +00:00
George Rimar 9fc1d4ed75 [ELF] - Updated comments. NFC.
As was suggested by Rafael Espíndola.

llvm-svn: 274111
2016-06-29 08:36:36 +00:00
Rui Ueyama 93c9af425e Create Strings.cpp and move string manipulation functions to that file.
llvm-svn: 274109
2016-06-29 08:01:32 +00:00
Rui Ueyama 722830a51b Rename matchStr -> globMatch.
llvm-svn: 274103
2016-06-29 05:32:09 +00:00
Rui Ueyama 48e4251e1d Make SymbolTable::findAll to return only defined symbols.
We allowed the function to return a vector that contains nullptrs
which is weird. This change makes the function to return only
defined symbols.

Differential Revision: http://reviews.llvm.org/D21828

llvm-svn: 274099
2016-06-29 04:47:39 +00:00
Davide Italiano 8e1131dc46 [ELF] Support for wildcard in version scripts.
Example:

VERSION_1.0 {
  global: foo*;
  local: *; }

now correctly matches all the symbols which name starts with
`foo`.

Differential Revision:  http://reviews.llvm.org/D21732

llvm-svn: 274091
2016-06-29 02:46:51 +00:00
Rui Ueyama 5e64d3fb94 Refactor ELF type inference functions.
Previously, we initialized Config->EKind and Config->EMachine when
we instantiate ELF objects. That was not an ideal location to do that
because the logic was buried too deep inside a concrete logic.

This patch moves the code to the driver so that the initialization
becomes explicit.

Differential Revision: http://reviews.llvm.org/D21784

llvm-svn: 274089
2016-06-29 01:30:50 +00:00
George Rimar 4365158689 [ELF] - Implemented support of default/non-default symbols versions
t is possible to create new version of symbol instead of depricated one
using combination of version script and asm commands. For example:

__asm__(".symver b_1,b@LIBSAMPLE_1.0");
int b_1() { return 10; }
__asm__(".symver b_2,b@@LIBSAMPLE_2.0");
int b_2() { return 20; }

This code makes b_2() to be default implementation for b().
b_1() is used for compatibility with binaries compiled against
library of older version LIBSAMPLE_1.0.

This patch implements support for above functionality in lld.

Differential revision: http://reviews.llvm.org/D21681

llvm-svn: 274002
2016-06-28 08:21:10 +00:00
George Rimar 36b2c0a683 [ELF] - Implemented --no-undefined-version flag
Option checks for cases where a version script explicitly lists
a symbol, but the symbol is not defined and errors out such
cases if any.

Differential revision: http://reviews.llvm.org/D21745

llvm-svn: 273998
2016-06-28 08:07:26 +00:00
Davide Italiano 4fdc648592 [ELF] Warn for duplicate symbols in version scripts instead of erroring out.
Emitting an error in this case breaks real-world application (e.g. libreoffice).
See http://reviews.llvm.org/D21555 for context.

Differential Revision:  http://reviews.llvm.org/D21781

llvm-svn: 273989
2016-06-28 03:40:49 +00:00
Rui Ueyama d60dae8a6a Implement --trace-symbol=symbol option.
Patch by Shridhar Joshi.

This option provides names of all the link time modules which define and
reference symbols requested by user. This helps to speed up application
development by detecting references causing undefined symbols.
It also helps in detecting symbols being resolved to wrong (unintended)
definitions in case of applications containing multiple definitions for
same symbols with different types, bindings.

Implements PR28226.

llvm-svn: 273536
2016-06-23 07:00:17 +00:00
George Rimar 50b80359c0 [ELF] - Do not allow to mix global symbols versions.
For next version script:
VER1{
  global:
  a;
};

VER2{
  global:
  a;
};
gold would produce warning like:
"warning: using 'VER1' as version for 'a' which is also named in version 'VER2' in script."

Documentation also says we do not want this duplications (https://people.freebsd.org/~deischen/symver/library_versioning.txt):
"Note that you do not want to duplicate symbols in the map file. The .symver directives are all that is required to add compatibility
symbols into old versions."

This patch restricts such mixing and makes lld to produce error in this case.

Differential revision: http://reviews.llvm.org/D21555

llvm-svn: 273396
2016-06-22 09:10:38 +00:00
George Rimar d3566309eb [ELF] - Recommit r273143("[ELF] - Basic versioned symbols support implemented.")
With fix:
-soname flag was not set in testcase. Hash calculated for base def was different on local
and bot machines because filename fos used for calculating.

Initial commit message:
Patch implements basic support of versioned symbols.
There is no wildcards patterns matching except local: *;
There is no support for hierarchies.
There is no support for symbols overrides (@ vs @@ not handled).

This patch allows programs that using simple scripts to link and run.

Differential revision: http://reviews.llvm.org/D21018

llvm-svn: 273152
2016-06-20 11:55:12 +00:00
George Rimar d03f97211a Revert r273143 "[ELF] - Basic versioned symbols support implemented."
It broke buildbot:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast

llvm-svn: 273146
2016-06-20 10:29:53 +00:00
George Rimar c31fee2212 [ELF] - Basic versioned symbols support implemented.
Patch implements basic support of versioned symbols.
There is no wildcards patterns matching except local: *;
There is no support for hierarchies.
There is no support for symbols overrides (@ vs @@ not handled).

This patch allows programs that using simple scripts to link and run.

Differential revision: http://reviews.llvm.org/D21018

llvm-svn: 273143
2016-06-20 10:16:33 +00:00
Rafael Espindola f70fb04e4f Make local: optional.
Doing that in an anonymous version is a bit silly, but this opens the
way for supporting it in general.

Since we don't support actual versions, for now we just disable the
version script if we detect that it is missing a local.

llvm-svn: 273000
2016-06-17 13:38:09 +00:00
Rafael Espindola cc70da39ff Internalize symbols in comdats.
We were dropping the CanOmitFromDynSym bit when creating undefined
symbols because of comdat.

llvm-svn: 272812
2016-06-15 17:56:10 +00:00
Rafael Espindola 65c65ce897 Don't include --start-lib/--end-lib files twice.
This should never happen with correct programs, but it is trivial
write a testcase where lld would crash or report duplicated
symbols. We now behave like when an archive is used and include the
file only once.

llvm-svn: 272724
2016-06-14 21:56:36 +00:00
Rafael Espindola 07543a8c2d Use a reference instead of a pointer. NFC.
llvm-svn: 272719
2016-06-14 21:40:23 +00:00
Peter Collingbourne ca8c994818 ELF: Compute used bit for --as-needed during symbol resolution.
We can now use this to decide whether to emit a verneed during the final
pass over the symbols. We were previously wrongly creating a verneed entry
in the case where all references to a DSO's symbols were weak.

In a future change we may also want to use the used bit to control whether
shared symbols are preemptible and appear in the dynsym. This seems a little
tricky to do at the moment because isNeeded() is templated.

The only other functional change here is that we emit a DT_NEEDED for DSOs
whose symbols are all preempted by objects that appear later in the link. But
that doesn't seem too important to me.

Differential Revision: http://reviews.llvm.org/D21171

llvm-svn: 272282
2016-06-09 18:01:35 +00:00
Rafael Espindola 78db5a9dca Print member name in undefined symbol error.
llvm-svn: 268976
2016-05-09 21:40:06 +00:00
Peter Collingbourne f3a2b0e8f7 ELF: Fix regression in TLS attribute mismatch logic.
Introduce a special symbol type to indicate that we have not yet seen a type
for the symbol, so we should not report TLS mismatches for that symbol.

Differential Revision: http://reviews.llvm.org/D19836

llvm-svn: 268411
2016-05-03 18:03:47 +00:00
Peter Collingbourne c357278a38 ELF: Remove the function SymbolTable<ELFT>::findFile.
We already have the function SymbolBody::getSourceFile which does the same thing.

llvm-svn: 268353
2016-05-03 01:48:25 +00:00
Peter Collingbourne 6a4225962d ELF: Forbid all relative relocations to absolute symbols in PIC, except for weak undefined.
Weak undefined symbols resolve to the image base. This is a little strange,
but it allows us to link function calls to such symbols. Normally such a
call will be guarded with a comparison, which will load a zero from the GOT.

There's one example of such a function call in crti.o in Linux's CRT.

As part of this change, I also needed to make the synthetic start and end
symbols image base relative in the case where their sections were empty,
so that PC-relative references to those symbols would continue to work.

Differential Revision: http://reviews.llvm.org/D19844

llvm-svn: 268350
2016-05-03 01:21:08 +00:00
Rui Ueyama 6d0cd2b62b Teach Undefined symbols from which file they are created from.
This patch increases the size of Undefined by the size of a pointer,
but it wouldn't actually increase the size of memory that LLD uses
because we are not allocating the exact size but the size of the
largest SymbolBody.

llvm-svn: 268310
2016-05-02 21:30:42 +00:00
Peter Collingbourne 4f9527065c ELF: New symbol table design.
This patch implements a new design for the symbol table that stores
SymbolBodies within a memory region of the Symbol object. Symbols are mutated
by constructing SymbolBodies in place over existing SymbolBodies, rather
than by mutating pointers. As mentioned in the initial proposal [1], this
memory layout helps reduce the cache miss rate by improving memory locality.

Performance numbers:

           old(s) new(s)
Without debug info:
chrome      7.178  6.432 (-11.5%)
LLVMgold.so 0.505  0.502 (-0.5%)
clang       0.954  0.827 (-15.4%)
llvm-as     0.052  0.045 (-15.5%)
With debug info:
scylla      5.695  5.613 (-1.5%)
clang      14.396 14.143 (-1.8%)

Performance counter results show that the fewer required indirections is
indeed the cause of the improved performance. For example, when linking
chrome, stalled cycles decreases from 14,556,444,002 to 12,959,238,310, and
instructions per cycle increases from 0.78 to 0.83. We are also executing
many fewer instructions (15,516,401,933 down to 15,002,434,310), probably
because we spend less time allocating SymbolBodies.

The new mechanism by which symbols are added to the symbol table is by calling
add* functions on the SymbolTable.

In this patch, I handle local symbols by storing them inside "unparented"
SymbolBodies. This is suboptimal, but if we do want to try to avoid allocating
these SymbolBodies, we can probably do that separately.

I also removed a few members from the SymbolBody class that were only being
used to pass information from the input file to the symbol table.

This patch implements the new design for the ELF linker only. I intend to
prepare a similar patch for the COFF linker.

[1] http://lists.llvm.org/pipermail/llvm-dev/2016-April/098832.html

Differential Revision: http://reviews.llvm.org/D19752

llvm-svn: 268178
2016-05-01 04:55:03 +00:00
George Rimar 9fc5908674 [ELF] Fixed warning. NFC.
SymbolTable.cpp:298:36: warning: enumeral and non-enumeral type in conditional expression [-Wextra]
     Sym->Binding = New->isShared() ? STB_GLOBAL : New->Binding;
                                    ^

llvm-svn: 268040
2016-04-29 13:32:30 +00:00
Rui Ueyama 62ee16faa8 Remove Size from Undefined symbol.
There seems to be no reason to keep st_size of undefined symbols.
This patch removes the member for it. This patch will change outputs
in cases that undefined symbols are copied to output, but I think
this is unimportant.

Differential Revision: http://reviews.llvm.org/D19574

llvm-svn: 267826
2016-04-28 00:26:54 +00:00
Rui Ueyama 1b70d666ae Do not lookup the symbol table twice for each --wrap.
llvm-svn: 267822
2016-04-28 00:03:38 +00:00
Peter Collingbourne 60976ed7c0 ELF: Merge UndefinedBitcode and UndefinedElf. NFC.
Differential Revision: http://reviews.llvm.org/D19566

llvm-svn: 267640
2016-04-27 00:05:06 +00:00
Peter Collingbourne 892d498017 ELF: Re-implement -u directly and remove CanKeepUndefined flag.
The semantics of the -u flag are to load the lazy symbol named by the flag. We
were previously relying on this behavior falling out of symbol resolution
against a synthetic undefined symbol, but that didn't quite give us the
correct behavior, so we needed a flag to mark symbols created with -u so
we could treat them specially in the writer. However, it's simpler and less
error prone to implement the required behavior directly and remove the flag.

This fixes an issue where symbols loaded with -u would receive hidden
visibility even when the definition in an object file had wider visibility.

Differential Revision: http://reviews.llvm.org/D19560

llvm-svn: 267639
2016-04-27 00:05:03 +00:00
Rafael Espindola 9e32e4fe86 Store the binding in the Symbol.
This remove a fixme, cleans up the weak undef interaction with archives and
lets us keep weak undefs still weak if they resolve to shared.

llvm-svn: 267555
2016-04-26 13:50:46 +00:00
Rui Ueyama 209f6cb055 Add more comment.
llvm-svn: 267260
2016-04-23 01:10:13 +00:00
Rui Ueyama 4255475139 Add comments.
llvm-svn: 267259
2016-04-23 00:26:32 +00:00
Peter Collingbourne 66ac1d6152 ELF: Implement basic support for --version-script.
This patch only implements support for version scripts of the form:
  { [ global: symbol1; symbol2; [...]; symbolN; ] local: *; };
No wildcards are supported, other than for the local entry. Symbol versioning
is also not supported.

It works by introducing a new Symbol flag which tracks whether a symbol
appears in the global section of a version script.

This patch also simplifies the logic in SymbolBody::isPreemptible(), and
teaches it to handle the case where symbols with default visibility in DSOs
do not appear in the dynamic symbol table because of a version script.

Fixes PR27482.

Differential Revision: http://reviews.llvm.org/D19430

llvm-svn: 267208
2016-04-22 20:21:26 +00:00
Peter Collingbourne e8d466293a Update an out of date comment.
llvm-svn: 267200
2016-04-22 19:56:45 +00:00
Peter Collingbourne dadcc17ead ELF: Move Visibility, IsUsedInRegularObj and MustBeInDynSym flags to Symbol.
These are properties of a symbol name, rather than a particular instance
of a symbol in an object file. We can simplify the code by collecting these
properties in Symbol.

The MustBeInDynSym flag has been renamed ExportDynamic, as its semantics
have been changed to be the same as those of --dynamic-list and
--export-dynamic-symbol, which do not cause hidden symbols to be exported.

Differential Revision: http://reviews.llvm.org/D19400

llvm-svn: 267183
2016-04-22 18:42:48 +00:00
Davide Italiano bc176631cd [LTO] Implement parallel Codegen for LTO using splitCodeGen.
Parallelism level can be chosen using the new --lto-jobs=K option
where K is the number of threads used for CodeGen. It currently
defaults to 1.

llvm-svn: 266484
2016-04-15 22:38:10 +00:00
Rafael Espindola 7f0b727235 Specialize the symbol table data structure a bit.
We never need to iterate over the K,V pairs, so we can avoid copying the
key as MapVector does.

This is a small speedup on most benchmarks.

llvm-svn: 266364
2016-04-14 20:42:43 +00:00
Adhemerval Zanella 9df0720766 ELF: Implement --dynamic-list
This patch implements the --dynamic-list option, which adds a list of
global symbol that either should not be bounded by default definition
when creating shared libraries, or add in dynamic symbol table in the
case of creating executables.

The patch modifies the ScriptParserBase class to use a list of Token
instead of StringRef, which contains information if the token is a
quoted or unquoted strings. It is used to use a faster search for
exact match symbol name.

The input file follow a similar format of linker script with some
simplifications (it does not have scope or node names). It leads
to a simplified parser define in DynamicList.{cpp,h}.

Different from ld/gold neither glob pattern nor mangled names
(extern 'C++') are currently supported.

llvm-svn: 266227
2016-04-13 18:51:11 +00:00
George Rimar 2a78fceb2c [ELF] - Change -t implementation to print which archive members are used.
Previously each archive file was reported no matter were it's member used or not,
like:
lib/libLLVMSupport.a

Now lld prints line for each used internal file, like:
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/StringSaver.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/Host.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/ConvertUTF.c.o)

That should be consistent with what gold do.

This fixes PR27243.

Differential revision: http://reviews.llvm.org/D19011

llvm-svn: 266220
2016-04-13 18:07:57 +00:00
Peter Collingbourne f6e9b4ec24 ELF: Use hidden visibility for all DefinedSynthetic symbols.
This simplifies the code by allowing us to remove the visibility argument
to functions that create synthetic symbols.

The only functional change is that the visibility of the MIPS "_gp" symbol
is now hidden. Because this symbol is defined in every executable or DSO, it
would be difficult to observe a visibility change here.

Differential Revision: http://reviews.llvm.org/D19033

llvm-svn: 266208
2016-04-13 16:57:28 +00:00
Rafael Espindola 8caf33c483 Cleanup the handling of MustBeInDynSym and IsUsedInRegularObj.
Now MustBeInDynSym is only true if the symbol really must be in the
dynamic symbol table.

IsUsedInRegularObj is only true if the symbol is used in a .o or -u. Not
a .so or a .bc.

A benefit is that this is now done almost entirilly during symbol
resolution. The only exception is copy relocations because of aliases.

This includes a small fix in that protected symbols in .so don't force
executable symbols to be exported.

This also opens the way for implementing internalize for -shared.

llvm-svn: 265826
2016-04-08 18:39:03 +00:00
Rui Ueyama f8baa66056 ELF: Implement --start-lib and --end-lib
start-lib and end-lib are options to link object files in the same
semantics as archive files. If an object is in start-lib and end-lib,
the object is linked only when the file is needed to resolve
undefined symbols. That means, if an object is in start-lib and end-lib,
it behaves as if it were in an archive file.

In this patch, I introduced a new notion, LazyObjectFile. That is
analogous to Archive file type, but that works for a single object
file instead of for an archive file.

http://reviews.llvm.org/D18814

llvm-svn: 265710
2016-04-07 19:24:51 +00:00
Rafael Espindola f47657301b Change the type hierarchy for undefined symbols.
We have to differentiate undefined symbols from bitcode and undefined
symbols from other sources.

Undefined symbols from bitcode should not inhibit the symbol being
internalized. Undefined symbols from other sources should.

llvm-svn: 265536
2016-04-06 13:22:41 +00:00
Rafael Espindola 5cea969dca Fix another case of propagating IsUsedRegularObj.
I have an idea on how to clean this up, but lets get the tests passing
first.

llvm-svn: 265374
2016-04-05 01:38:43 +00:00
Peter Collingbourne d0856a6bb2 ELF: Make SymbolBody::compare a non-template function.
Differential Revision: http://reviews.llvm.org/D18781

llvm-svn: 265372
2016-04-05 00:47:58 +00:00
Peter Collingbourne e8afa4971c ELF: Preserve MustBeInDynSym for bitcode symbols.
Make sure to copy the MustBeInDynSym field when replacing shared symbols with
bitcode symbols, and when replacing bitcode symbols with regular symbols
in addCombinedLtoObject. Fixes interposition of DSO symbols with bitcode
symbols in the main executable.

Differential Revision: http://reviews.llvm.org/D18780

llvm-svn: 265371
2016-04-05 00:47:55 +00:00
Rafael Espindola ccfe3cb3d6 Don't store an Elf_Sym for most symbols.
Our symbol representation was redundant, and some times would get out of
sync. It had an Elf_Sym, but some fields were copied to SymbolBody.

Different parts of the code were checking the bits in SymbolBody and
others were checking Elf_Sym.

There are two general approaches to fix this:
* Copy the required information and don't store and Elf_Sym.
* Don't copy the information and always use the Elf_Smy.

The second way sounds tempting, but has a big problem: we would have to
template SymbolBody. I started doing it, but it requires templeting
*everything* and creates a bit chicken and egg problem at the driver
where we have to find ELFT before we can create an ArchiveFile for
example.

As much as possible I compared the test differences with what gold and
bfd produce to make sure they are still valid. In most cases we are just
adding hidden visibility to a local symbol, which is harmless.

In most tests this is a small speedup. The only slowdown was scylla
(1.006X). The largest speedup was clang with no --build-id, -O3 or
--gc-sections (i.e.: focus on the relocations): 1.019X.

llvm-svn: 265293
2016-04-04 14:04:16 +00:00
Davide Italiano c4965009bd [ELF] Prefer 'auto' over explicit type for consistency.
llvm-svn: 265250
2016-04-02 23:47:54 +00:00
Davide Italiano 4fda708624 [LTO] Fix symbols which were internalized incorrectly.
If a symbol is defined in an archive, when we replace its body
the isUsedInRegularObj wasn't set correctly. Internalize makes
its decision based on that bit so we ended up internalizing
symbols that we shouldn't (because they're referenced).
This should fix. Thanks to Peter and Rafael for discussion
and help diagnosing the issue!

Found during LTO of unittests.

llvm-svn: 265208
2016-04-02 02:10:40 +00:00
Rui Ueyama 01ddc06484 Make BitcodeCompiler::compile a non-template function. NFC.
llvm-svn: 264770
2016-03-29 19:08:46 +00:00
Davide Italiano 04d6aa2b38 [LTO] Include in .symtab/.dynsym symbols introduced by optimizations.
Some optimizations, e.g. SimplifyLibCalls, can replace functions with
others as part of the lowering, e.g. printf => puts.
The new symbols don't have the isUsedInRegularObj flag set so they
don't get included in the final symbol table (and dynamic symbol
table), and the dynamic linker gets confused. Include  them as a fix.

Differential Revision: http://reviews.llvm.org/D18357

llvm-svn: 264688
2016-03-29 00:15:52 +00:00
Rui Ueyama 259924869b ELF: Create LTO.{cpp,h} and move LTO-related code to that file.
The code for LTO has been growing, so now is probably a good time to
move it to its own file. SymbolTable.cpp is for symbol table, and
because compiling bitcode files are semantically not a part of
symbol table, this is I think a good thing to do.

http://reviews.llvm.org/D18370

llvm-svn: 264091
2016-03-22 20:52:10 +00:00
Sean Silva 3baa23b50c [lto] Provide a file name for the combined LTO object.
Otherwise, we get diagnostics like:

    undefined symbol: foo in

Which isn't particularly useful.

llvm-svn: 264089
2016-03-22 20:25:32 +00:00
Davide Italiano ac8737ac60 [ELF] Refactor run of LTO passes into an helper. NFC.
Requested by: Rui Ueyama.

llvm-svn: 263851
2016-03-18 23:22:40 +00:00
Davide Italiano c20c061749 [LTO] Call the optimizer before invoking codegen.
This is the required plumbing needed to run the LTO passes.

Differential Revision:  http://reviews.llvm.org/D18235

llvm-svn: 263761
2016-03-17 23:35:34 +00:00
George Rimar 786e866fea [ELF] - -pie/--pic-executable option implemented
-pie
--pic-executable

Create a position independent executable.  This is currently only
 supported on ELF platforms.  Position independent executables are
 similar to shared libraries in that they are relocated by the
 dynamic linker to the virtual address the OS chooses for them
 (which can vary between invocations).  Like normal dynamically
 linked executables they can be executed and symbols defined in the
 executable cannot be overridden by shared libraries.

Differential revision: http://reviews.llvm.org/D18183

llvm-svn: 263693
2016-03-17 05:57:33 +00:00
George Rimar 777f96304e Recommit of r263252, [ELF] - Change all messages to lowercase to be consistent.
which was reverted because included
unrelative changes by mistake.

Original commit message:

[ELF] - Change all messages to lowercase to be consistent.

That is directly opposite to http://reviews.llvm.org/D18045,
which was reverted.

This patch changes all messages to start from lowercase letter if
they were not before.

That is done to be consistent with clang.

Differential revision: http://reviews.llvm.org/D18085

llvm-svn: 263337
2016-03-12 08:31:34 +00:00
Rui Ueyama f714955402 Revert r263252: "[ELF] - Change all messages to lowercase to be consistent."
This reverts commit r263252 because the change contained unrelated changes.

llvm-svn: 263272
2016-03-11 18:46:51 +00:00
George Rimar 96bcdae1a5 [ELF] - Change all messages to lowercase to be consistent.
That is directly opposite to http://reviews.llvm.org/D18045,
which was reverted.

This patch changes all messages to start from lowercase letter if
they were not before.

That is done to be consistent with clang.

Differential revision: http://reviews.llvm.org/D18085

llvm-svn: 263252
2016-03-11 16:40:55 +00:00
Rafael Espindola 36a73d2deb More MSVC fixes.
llvm-svn: 263251
2016-03-11 16:32:46 +00:00
Rafael Espindola 9b3acf9098 Avoid calling getNamedValue.
In lld we usually avoid hash lookups. In addition to that, IR names are
not fully mangled, so it is best to avoid using them whenever possible.

llvm-svn: 263248
2016-03-11 16:11:47 +00:00
George Rimar 5761042db7 This reverts the r263125
It was discussed to make all messages be 
lowercase to be consistent with clang.
(also reverts the r263128 which fixed 
build bot fail after r263125)

Original commit message:
[ELF] - Consistent spelling for error/warning messages

Previously error and warnings were not consistent in lld.
Some of them started from lowercase letter, others from
uppercase. Also there was one or two which had a dot at the end.
This patch changes all messages to start from uppercase letter if
they were not before.

Differential revision: http://reviews.llvm.org/D18045

llvm-svn: 263240
2016-03-11 14:43:02 +00:00
Rafael Espindola 67d72c02bc Create a SymbolBody for locals.
pr26878 shows a case where locals have to be in the got.

llvm-svn: 263222
2016-03-11 12:06:30 +00:00
Sean Silva b1b5cc83f1 [lto] Make sure that ctors are added to the combined module.
Summary:
More generally, appending linkage is a special case that we don't want
to create a SymbolBody for.

Reviewers: rafael, ruiu

Subscribers: Bigcheese, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18012

llvm-svn: 263179
2016-03-11 00:50:05 +00:00
George Rimar e094388861 [ELF] - Consistent spelling for error/warning messages
Previously error and warnings were not consistent in lld.
Some of them started from lowercase letter, others from
uppercase. Also there was one or two which had a dot at the end.
This patch changes all messages to start from uppercase letter if
they were not before.

Differential revision: http://reviews.llvm.org/D18045

llvm-svn: 263125
2016-03-10 16:58:34 +00:00
Sean Silva 4aaeac6ad3 [lto] Add saving the LTO .o file to -save-temps.
Summary:
This implements another part of -save-temps.
After this, the only remaining part is dumping the optimized bitcode. But
currently LLD's LTO doesn't have a non-intrusive place to put this.
Eventually we probably will and it will make sense to add it then.

Reviewers: ruiu, rafael

Subscribers: joker.eph, Bigcheese, llvm-commits

Differential Revision: http://reviews.llvm.org/D18009

llvm-svn: 263070
2016-03-09 22:30:05 +00:00
Sean Silva c43ec673b9 Update for Rui's comments on D18006
Somehow I missed them.

llvm-svn: 263057
2016-03-09 20:06:24 +00:00
Sean Silva 35ef3d95eb [lto] Add beginning of -save-temps option.
Summary:
This is useful for debugging issues with LTO.
The option follows the analogous option in ld64 and the gold plugin (per
Rafael's suggestion).

For starters, this only dumps the combined bitcode file.
In a future patch I will add dumping for the .o file.

The naming of the output follows ld64's convention which is slightly more
consistent IMO (consistent `.lto.<extension>` for all the files).

Reviewers: rafael, ruiu

Subscribers: joker.eph, Bigcheese, llvm-commits

Differential Revision: http://reviews.llvm.org/D18006

llvm-svn: 263055
2016-03-09 20:01:08 +00:00
Sean Silva 50d27ff3c1 [lto] Don't lazy load metadata for now.
Summary:
At the very least we hit

    Assertion failed: (((Flags & RF_HaveUnmaterializedMetadata) || Node->isResolved()) && "Unexpected unresolved node"), function MapMetadataImpl, file /Users/Sean/pg/llvm/lib/Transforms/Utils/ValueMapper.cpp, line 375.

on the included test case.

We currently do things like parse the module twice to keep the
implementation minimal. I think it makes sense to add start with eager
loading for similar reasons.

Reviewers: rafael

Subscribers: ruiu, Bigcheese, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D17982

llvm-svn: 263045
2016-03-09 18:38:40 +00:00
George Rimar 2f0fab53e4 [ELF] - Simplify a SymbolBody class interface a bit.
Get rid of few accessors in that class, and replace
them with direct fields access.

Differential revision: http://reviews.llvm.org/D17879

llvm-svn: 262796
2016-03-06 06:26:18 +00:00
Rafael Espindola 7f6d50b229 Use IRMover directly.
This has a few advantages:
* If lld selected a non bitcode symbol, be the bitcode GV is not merged
* lib/Linker is not redoing symbol resolution.

llvm-svn: 262773
2016-03-05 14:51:51 +00:00
Davide Italiano 255730cdc5 [ELF] Generalize symbol type handling.
SymbolBody constructor and friends take isFunc and isTLS boolean arguments.
ELF symbols have already a type so than be easily passed as argument.
If we want to support another type, this scheme is not good enough, that is,
the current code logic would require passing another `bool isObject` around.
Up to two argument, this stretching exercise was a little bit goofy but
still acceptable, but with more types to support, is just too much, IMHO.

Change the code so that the type is passed instead.

Differential Revision:   http://reviews.llvm.org/D17871

llvm-svn: 262684
2016-03-04 01:55:28 +00:00
Rafael Espindola 75714f618c Rename 'fatal' to 'check' when it doesn't always fail.
llvm-svn: 262666
2016-03-03 22:24:39 +00:00
Rafael Espindola 1130935c4a Simplify error handling.
This makes fatal return T when there is no error. This avoids the need
for quite a few temporaries.

llvm-svn: 262626
2016-03-03 16:21:44 +00:00
Rafael Espindola cdf3a2a5be 1Fix handling of undef in partial LTO.
llvm-svn: 262497
2016-03-02 18:21:46 +00:00
Rafael Espindola 3ca9ee0c53 LTO: Use the correct relocation model.
llvm-svn: 262492
2016-03-02 17:21:06 +00:00
Rafael Espindola 4de44b7ef8 Handle comdat in LTO.
llvm-svn: 262489
2016-03-02 15:43:50 +00:00
George Rimar aa4dc20f09 [ELF] - Create _DYNAMIC symbol for dynamic output
lld needs to provide _DYNAMIC symbol when creating a shared library
both bfd and gold do that.

This should fix the https://llvm.org/bugs/show_bug.cgi?id=26732

Differential revision: http://reviews.llvm.org/D17607

llvm-svn: 262348
2016-03-01 16:23:13 +00:00
Rafael Espindola 9bcbfd7d42 Remove bogus assert.
llvm-svn: 262219
2016-02-29 13:46:39 +00:00
Rafael Espindola e0df00b91f Rename elf2 to elf.
llvm-svn: 262159
2016-02-28 00:25:54 +00:00
Rafael Espindola 18f0950783 Report duplicated symbols in bitcode.
llvm-svn: 262076
2016-02-26 21:49:38 +00:00
Rafael Espindola 297ce4ece9 Make SymbolBodies private.
This makes BitcodeFile a bit closer to ObjectFile.

If anyone prefers I can go the other way and delete getSymbols from
ObjectFile.

llvm-svn: 262072
2016-02-26 21:31:34 +00:00
Rafael Espindola 8176d57d62 Handle a weak undefined tls to archive member.
A weak undefined should not fetch archive members, so we have to keep
the Lazy symbol.

That means the lazy symbol has to encode information about the original
weak undef.

Fixes pr25762.

llvm-svn: 261591
2016-02-22 23:19:29 +00:00
Rafael Espindola 5e8b54afdb Remove a trivial getter.
llvm-svn: 261590
2016-02-22 23:16:05 +00:00
Rafael Espindola 9f77ef0c08 Add initial LTO support.
llvm-svn: 260726
2016-02-12 20:54:57 +00:00
Rafael Espindola abebed982a Rename IsUsedInDynamicReloc to MustBeInDynSym.
The variable was marking various cases where a symbol must be included
in the dynamic symbol table. Being used by a dynamic relocation was only
one of them.

llvm-svn: 259889
2016-02-05 15:27:15 +00:00
Rui Ueyama 71c066d8cf ELF: Include archive names in error messages.
If object files are drawn from archive files, the error message should
be something like "conflict symbols in foo.a(bar.o) and baz.o" instead
of "conflict symbols in bar.o and baz.o". This patch implements that.

llvm-svn: 259475
2016-02-02 08:22:41 +00:00
Rui Ueyama 16ba669c87 ELF: Report duplicate symbols as many as possible instead of the first one.
http://reviews.llvm.org/D16647

llvm-svn: 259233
2016-01-29 19:41:13 +00:00
Rui Ueyama 64cfffd333 ELF: Rename error -> fatal and redefine error as a non-noreturn function.
In many situations, we don't want to exit at the first error even in the
process model. For example, it is better to report all undefined symbols
rather than reporting the first one that the linker picked up randomly.

In order to handle such errors, we don't need to wrap everything with
ErrorOr (thanks for David Blaikie for pointing this out!) Instead, we
can set a flag to record the fact that we found an error and keep it
going until it reaches a reasonable checkpoint.

This idea should be applicable to other places. For example, we can
ignore broken relocations and check for errors after visiting all relocs.

In this patch, I rename error to fatal, and introduce another version of
error which doesn't call exit. That function instead sets HasError to true.
Once HasError becomes true, it stays true, so that we know that there
was an error if it is true.

I think introducing a non-noreturn error reporting function is by itself
a good idea, and it looks to me that this also provides a gradual path
towards lld-as-a-library (or at least embed-lld-to-your-program) without
sacrificing code readability with lots of ErrorOr's.

http://reviews.llvm.org/D16641

llvm-svn: 259069
2016-01-28 18:40:06 +00:00
Rafael Espindola 65e80b963a Rename IgnoredWeak to Ignored.
Thanks to Rui for the suggestion.

llvm-svn: 258189
2016-01-19 21:19:52 +00:00
Rafael Espindola 3a6a0a0109 Delete addIgnoredStrong.
It is not needed now that we resolve symbols is shared libraries
correctly.

llvm-svn: 258104
2016-01-19 00:05:54 +00:00
Rui Ueyama a4a628fb51 Demangle symbols when including them in error messages.
llvm-svn: 257647
2016-01-13 18:55:39 +00:00
Rui Ueyama 09eb0b3b3f Rename IgnoredUndef -> Ignored since it is not an undefined symbol.
Also rename Ignored -> IgnoredWeak and IgnoredStrong -> Ignored,
since strong symbol is a norm.

llvm-svn: 257507
2016-01-12 19:24:55 +00:00
Simon Atanasyan 188558e5eb [ELF][MIPS] Prevent substitution of _gp_disp symbol
On MIPS O32 ABI, _gp_disp is a magic symbol designates offset between
start of function and gp pointer into GOT. To make seal with such symbol
we add new method addIgnoredStrong(). It adds ignored symbol with global
binding to prevent the symbol substitution. The addIgnored call is not
enough here because this call adds a weak symbol which might be
substituted by symbol from shared library.

Differential Revision: http://reviews.llvm.org/D16084

llvm-svn: 257449
2016-01-12 06:23:57 +00:00
Rui Ueyama 131e0ffa10 Use shorter name. NFC.
llvm-svn: 257217
2016-01-08 22:17:42 +00:00
Rui Ueyama 8b4879aec0 Remove an empty constructor.
We used to have code in SymbolTable constructor to add entry symbols, etc.
That code has been moved to Driver. We can remove the constructor.

llvm-svn: 257214
2016-01-08 22:06:25 +00:00
Rui Ueyama b4de595c46 Add comments.
llvm-svn: 257212
2016-01-08 22:01:33 +00:00
Rui Ueyama 79c7373232 ELF: Consistently return SymbolBody * from SymbolTable::add functions.
For historical reasons, some add* functions for SymbolTable returns a
pointer to a SymbolBody, while some are not. This patch is to make them
consistently return a pointer to a newly added symbol.

llvm-svn: 257211
2016-01-08 21:53:28 +00:00
Rui Ueyama deb154001d ELF: Implement --wrap.
In this patch, all symbols are resolved normally and then wrap options
are applied. Renaming is implemented by mutating `Body` pointers of
Symbols. (As a result, Symtab.find(SymbolName)->getName() may return
a string that's different from SymbolName, but that is by design.
I designed the symbol and the symbol table to allow this kind of
operations.)

http://reviews.llvm.org/D15896

llvm-svn: 257075
2016-01-07 17:20:07 +00:00
Rui Ueyama 52d3b67c1d Rename Comdats -> ComdatGroups.
I usually prefer short names, but in this case the new descriptive
name should improve readability a bit.

llvm-svn: 256899
2016-01-06 02:06:33 +00:00
Rui Ueyama 7c713319b9 Rename SharedFile::parse -> SharedFile::parseRest.
Unlike ObjectFile or ArchiveFile, SharedFile had two parse functions,
parseSoName() and parse(). parse must have been called after parseSoName,
but that requirement was not obvious from their names. (So it looked
like you could call parse() on a shared object file right away.)

This patch rename parseRest. It is now obvious that there's no single
parse function for the shared object file.

llvm-svn: 256898
2016-01-06 01:56:36 +00:00
Rui Ueyama f588ac4663 Simplify. NFC.
llvm-svn: 256879
2016-01-06 00:09:41 +00:00
Rui Ueyama 2e0a9fff12 Fix local variable naming.
llvm-svn: 256878
2016-01-06 00:09:39 +00:00
Rui Ueyama c9559d9378 Add comments.
llvm-svn: 256872
2016-01-05 20:47:37 +00:00
Rui Ueyama 2ef58a18af Remove SymbolTable::isUndefined.
Because it can be implemented outside of the symbol table.

llvm-svn: 256869
2016-01-05 20:35:16 +00:00
Rui Ueyama 2a65a49bcf Make findFile() a member function of SymbolTable to simplify. NFC.
llvm-svn: 256867
2016-01-05 20:01:29 +00:00
Rui Ueyama a246e094bc Factor out static members from DefinedRegular.
This patch moves statically-allocated Elf_Sym objects out
of DefinedRegular class, so that the class definition becomes
smaller.

llvm-svn: 256408
2015-12-25 06:12:18 +00:00
Rafael Espindola 02ce26a1b4 Delete DefinedAbsolute.
There are 3 symbol types that a .bc can provide during lto: defined,
undefined, common.

Defined and undefined symbols have already been refactored. I was
working on common and noticed that absolute symbols would become an
oddity: They would be the only symbol type present in a .o but not in
a.bc.

Looking a bit more, other than the special section number they were only
used for special rules for computing values. In that way they are
similar to TLS, and we don't have a DefinedTLS.

This patch deletes it. With it we have a reasonable rule of the thumb
for having a symbol kind: It exists if it has special resolution
semantics.

llvm-svn: 256383
2015-12-24 14:22:24 +00:00
Rui Ueyama 01a65b19cf Add comments.
llvm-svn: 256380
2015-12-24 10:37:32 +00:00
Rafael Espindola 4d4b06a0f8 Split Defined and DefinedElf.
This is similar to what was done for Undefined and opens the way for
having a symbol defined in bitcode.

llvm-svn: 256354
2015-12-24 00:47:42 +00:00
Rafael Espindola 21f7bd4ba1 Simplify memory management.
We no longer need an explicit delete or a polymorphic destructor.

llvm-svn: 256333
2015-12-23 14:35:51 +00:00
Rafael Espindola 05b0375e93 Fix an asan found leak.
I will make better use of std::unique_ptr in followup patch.

llvm-svn: 256310
2015-12-23 01:14:37 +00:00
Rafael Espindola 5d7593bc59 Split Undefined and UndefinedElf.
I am working on adding LTO support to the new ELF lld.

In order to do that, it will be necessary to represent defined and
undefined symbols that are not from ELF files. One way to do it is to
change the symbol hierarchy to look like

Defined : SymbolBody
Undefined : SymbolBody

DefinedElf<ELFT> : Defined
UndefinedElf<ELFT> : Undefined

Another option would be to use bogus Elf_Sym, but I think that is
getting a bit too hackish.

This patch does the Undefined/UndefinedElf. Split. The next one
will do the Defined/DefinedElf split.

llvm-svn: 256289
2015-12-22 23:00:50 +00:00
Rafael Espindola 8a9f90e669 Refactor duplicated code. NFC.
llvm-svn: 256180
2015-12-21 19:09:19 +00:00
Rui Ueyama 62d0e3297b ELF: Rename isTLS -> isTls for consistency.
llvm-svn: 255855
2015-12-17 00:04:18 +00:00
Rui Ueyama 3554f59f5d ELF: Remove a dumb constructor.
Symbol is a struct and can be initialized using an initializer.

llvm-svn: 255854
2015-12-17 00:01:25 +00:00
Rui Ueyama 6192c122f4 ELF: Move shouldUseRela to Writer.cpp.
The function was used only in Writer.cpp and did not depend on SymbolTable.
There is no reason to have that function in SymbolTable.cpp.

llvm-svn: 255850
2015-12-16 23:33:56 +00:00
Rui Ueyama 25b44c9b2b ELF: Make checkCompatibility a non-member function.
Because the function does not use any member of SymbolTable class.

llvm-svn: 255849
2015-12-16 23:31:22 +00:00
Rui Ueyama 38dcc9e355 Simplify. NFC.
llvm-svn: 255846
2015-12-16 23:25:31 +00:00
Rui Ueyama c5b9512958 ELF: Remove duplicate code.
We had duplicate code that were called before addMemberFile.
This patch makes them to be called at beginning of addMemberFile.

llvm-svn: 255845
2015-12-16 23:23:14 +00:00
Rui Ueyama 8957574549 ELF: Remove SymbolTable::addELFFile.
addELFFile was called only from addFile, and what it did was actually
just adding a file to the symbol table. There seems to be no reason
to separate the two.

llvm-svn: 255839
2015-12-16 22:59:13 +00:00
Rui Ueyama a71f3a71cc Do not omit * from auto.
We don't do that in other places in the same file.

llvm-svn: 255833
2015-12-16 22:36:10 +00:00
Rui Ueyama dd7d998919 ELF: Drop 'Sym' suffix from member function names for consistency.
Since the functions are members of SymbolTable class, it is obvious
that they are adding symbols.

llvm-svn: 255832
2015-12-16 22:31:14 +00:00
Rui Ueyama 533336a368 ELF: Factor out common code. NFC.
llvm-svn: 255830
2015-12-16 22:26:48 +00:00
Rui Ueyama f09040120f ELF: Separate error message generation from call of error() or warning().
Previously reportConflict returned only when the third argument is false.
Now it always returns a value.

llvm-svn: 255829
2015-12-16 22:26:45 +00:00
Simon Atanasyan 09dae7c3e7 [ELF][MIPS] Handle R_MIPS_HI16/LO16 relocations against _gp_disp symbol
The `_gp_disp` is a magic symbol designates offset between start of
function and gp pointer into GOT. Only `R_MIPS_HI16` and `R_MIPS_LO16`
relocations are permitted with `_gp_disp`. The patch adds the `_gp_disp`
as an ignored symbol and adjusts symbol value before call the `relocateOne`
for `R_MIPS_HI16/LO16` relocations.

Differential Revision: http://reviews.llvm.org/D15480

llvm-svn: 255768
2015-12-16 14:45:09 +00:00
Igor Kudrin 4bc5ad4c37 [ELF] Prevent SEGFAULT in case of conflict with an internally defined symbol.
Differential Revision: http://reviews.llvm.org/D14832

llvm-svn: 253588
2015-11-19 19:08:45 +00:00
Igor Kudrin 15cd9ffd1e [ELF2] Add GOT section for MIPS target.
This patch implements R_MIPS_GOT16 relocation for global symbols in order to
generate some entries in GOT. Only reserved and global entries are supported
for now. For the detailed description about GOT in MIPS, see "Global Offset
Table" in Chapter 5 in the followin document:
ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf

In addition, the platform specific symbol "_gp" is added, see "Global Data
Symbols" in Chapter 6 in the aforementioned document.

Differential revision: http://reviews.llvm.org/D14211

llvm-svn: 252275
2015-11-06 07:43:03 +00:00
Rui Ueyama c7cc6ecf08 ELF2: Use ELFT to template OutputSections.
This patch is to use ELFT instead of Is64Bits to template OutputSection
and its subclasses. This increases code size slightly because it creates
two identical functions for some classes, but that's only 20 KB out of
33 MB, so it's negligible.

This is as per discussion with Rafael. He's not fan of the idea but OK
with this. We'll revisit later to this topic.

llvm-svn: 250466
2015-10-15 22:27:29 +00:00
Rui Ueyama d9189ceb23 ELF2: Implement __start_SECNAME and __stop_SECNAME.
If a section name is valid as a C identifier (which is rare because of
the leading '.'), linkers are expected to define __start_<secname> and
__stop_<secname> symbols. They are at beginning and end of the section,
respectively. This is not requested by the ELF standard, but GNU ld and
gold provide this feature.

llvm-svn: 250432
2015-10-15 17:11:03 +00:00
Rafael Espindola ae81a7bf49 Use OutputSectionBase in a few cases where we don't need a OutputSection.
NFC. This is just preparation for adding a new OutputSection dedicated to
SHF_MERGE input sections.

llvm-svn: 250419
2015-10-15 15:29:53 +00:00
Rui Ueyama 690db6786e Simplify.
llvm-svn: 250337
2015-10-14 22:32:10 +00:00
Rui Ueyama 34f2924675 ELF2: Add comments.
llvm-svn: 250215
2015-10-13 19:51:57 +00:00
Rui Ueyama 93bfee5f70 ELF2: Avoid using "finalize" as a function name.
"finalize" does not give a hint about what that function is actually
going to do. This patch make it more specific by renaming scanShlibUndefined.
Also add a comment that we basically ignore undefined symbols in DSOs except
this function.

llvm-svn: 250191
2015-10-13 18:10:33 +00:00
Rui Ueyama f8432d97f3 ELF2: Fix BSD's __progname symbol issue.
BSD's DSO files have undefined symbol "__progname" which is defined
in crt1.o. On that system, both user programs and system shared
libraries depend on each other.

In general, we need to put symbols defined by user programs which are
referenced by shared libraries to user program's .dynsym.

http://reviews.llvm.org/D13637

llvm-svn: 250176
2015-10-13 16:34:14 +00:00
Rui Ueyama e717a7195b ELF2: Rename ElfKind -> EKind.
ELFKind as a type name and ElfKind is a variable name was too subtle.

llvm-svn: 250172
2015-10-13 16:20:50 +00:00
Rui Ueyama 3d45179d56 ELF2: Split SymbolTable::addFile(). NFC.
llvm-svn: 250073
2015-10-12 18:03:21 +00:00
Rafael Espindola b9ca7bb6ab Delete getFirstELF.
llvm-svn: 250030
2015-10-12 11:52:31 +00:00
Rafael Espindola dfce5a25cb Simplify the InputFile type hierarchy by removing unnecessary middle classses.
llvm-svn: 250006
2015-10-12 02:22:58 +00:00
Rafael Espindola af70764aa1 Simplify the InputFile type hierarchy.
Now that the SymbolTable is templated, we don't need the ELFData class or
multiple inheritance.

llvm-svn: 250005
2015-10-12 01:55:32 +00:00
Rafael Espindola 9afbac479f Handle a crash in conflict detection with archive members.
llvm-svn: 249996
2015-10-11 20:19:20 +00:00
Rafael Espindola 525914defd Detect incompatible files when one of them comes from an archive.
llvm-svn: 249968
2015-10-11 03:36:49 +00:00
Rui Ueyama ff77768569 ELF2: Move Target and entry initialization from SymbolTable to Driver.
SymbolTable was not a right place for initialization. We had to do that
because Driver didn't know what type of ELF objects are being handled.
We taught Driver that, so we can now move this code to Driver.

llvm-svn: 249904
2015-10-09 21:12:40 +00:00
Rui Ueyama 3ce825ed26 ELF2: Make SymbolTable a template class.
SymbolTable was not a template class. Instead we had switch-case-based
type dispatch to call desired functions. We had to do that because
SymbolTable was created before we know what ELF type objects had been
passed.

Every time I tried to add a new function to the symbol table, I had to
define a dispatcher which consist of a single switch statement.

It also brought an restriction what the driver can do. For example,
we cannot add undefined symbols before any files are added to the symbol
table. That's because no symbols can be added until the symbol table
knows the ELF type, but when it knows about that, it's too late.

In this patch, the driver makes a decision on what ELF type objects
are being handled. Then the driver creates a SymbolTable object for
an appropriate ELF type.

http://reviews.llvm.org/D13544

llvm-svn: 249902
2015-10-09 21:07:25 +00:00
Rafael Espindola 444576d4c4 Add support for comdats.
The implementation is a direct translation to c++ of the rules in the ELF spec.

llvm-svn: 249881
2015-10-09 19:25:07 +00:00
Igor Kudrin 65bddeaacf [ELF2] Check for TLS mismatch in symbol resolution.
The linker should generate an error if a TLS symbol is resolved
for a non-TLS reference and vice versa.

The patch addresses PR24244 (https://llvm.org/bugs/show_bug.cgi?id=24244)

Differential Revision: http://reviews.llvm.org/D13550

llvm-svn: 249817
2015-10-09 09:58:39 +00:00
Rui Ueyama aca48ffb41 ELF2: Inititalize other symbols only once as well.
llvm-svn: 249645
2015-10-08 00:44:28 +00:00
Rui Ueyama 833ce281db ELF2: Make member variable names shorter.
I'm going to use them in other patches, and the names feel too long
despite their narrow scope.

llvm-svn: 249642
2015-10-08 00:29:00 +00:00
Rui Ueyama 9ea49c7948 ELF2: Initialize SyntheticOptional only once.
llvm-svn: 249636
2015-10-07 23:46:11 +00:00
Rui Ueyama e1f91529c8 ELF2: Rename dupError() -> reportConflict().
llvm-svn: 249622
2015-10-07 21:37:24 +00:00
Denis Protivensky 1ef7b3ff55 [ELF2] Handle -m option
Parse and apply emulation given with -m option.
Check input files to match ELF type and machine architecture provided with -m.

Differential Revision: http://reviews.llvm.org/D13055

llvm-svn: 249529
2015-10-07 09:13:03 +00:00
Rafael Espindola c05ad3dedb Create linker generated symbols earlier.
We were incorrectly deciding that a dynamic relocation was needed for them.

llvm-svn: 249512
2015-10-07 02:51:44 +00:00
Michael J. Spencer f32446fb65 [elf2] Correctly determine if we should ignore missing __tls_get_addr.
llvm-svn: 249462
2015-10-06 20:39:09 +00:00
Rafael Espindola 85a6e0f870 Never fetch members for weak undefined symbols.
We were still fetching them when the archive was seen first.

We should experiment with just letting lazy symbols get to compare, it
might be cleaner for ELF.

llvm-svn: 249417
2015-10-06 15:18:50 +00:00
Rafael Espindola b90582dbbd Avoid recursive calls to init (we would crash).
llvm-svn: 249412
2015-10-06 15:03:52 +00:00
Rafael Espindola 8614c566e2 Handle strong undefined symbols fetching members after a weak undefined.
This is a case that requires --start-group --end-group with regular ELF
linkers. Fortunately it is still possible to handle it with lazy symbols without
taking a second look at archives.

Thanks to Michael Spencer for the bug report.

llvm-svn: 249406
2015-10-06 14:33:58 +00:00
Michael J. Spencer 4c46f57a49 [elf2] Ignore __tls_get_addr when static linking.
llvm-svn: 249365
2015-10-06 00:45:42 +00:00
Denis Protivensky 22220d5d5f [ELF2] Add --undefined option
Add symbol specified with -u as undefined which may cause additional
object files from archives to be linked into the resulting binary.

Differential Revision: http://reviews.llvm.org/D13345

llvm-svn: 249295
2015-10-05 09:43:57 +00:00
Rafael Espindola b2a5cafb37 Weak undefined symbols should not fetch archive members.
llvm-svn: 249160
2015-10-02 17:41:22 +00:00
Rafael Espindola 5d41326751 Still define __init_array_(start|end) if there is no .init_array.
This matches the behavior of other linkers and seems necessary to link
in some older systems.

llvm-svn: 249077
2015-10-01 21:22:26 +00:00
Rafael Espindola d31088b37a Simplify instantiation. NFC.
llvm-svn: 249074
2015-10-01 21:18:37 +00:00
Rafael Espindola 6a3b5ded8a Don't include shared libraries multiple times.
llvm-svn: 249061
2015-10-01 19:52:48 +00:00
Igor Kudrin 2696bbeb93 [ELF2] Add --[no-]whole-archive command line switches
Summary:
If --whole-archive is used, all symbols from the following archives are added to the output. --no-whole-archive restores default behavior. These switches can be used multiple times.

NB. We have to keep an ArchiveFile instance within SymbolTable even if --whole-archive mode is active since it can be a thin archive which contains just names of external files. In that case actual memory buffers for the archive members will be stored within the File member of ArchiveFile class.

Reviewers: rafael, ruiu

Subscribers: grimar, llvm-commits

Projects: #lld

Differential Revision: http://reviews.llvm.org/D13286

llvm-svn: 249045
2015-10-01 18:02:21 +00:00
Rui Ueyama 9d4c6d771b [ELF2] Implemented --entry flag.
Patch from George Rimar!

llvm-svn: 248806
2015-09-29 16:40:13 +00:00
Simon Atanasyan 49829a1bfe [ELF2] Add initial MIPS support
Besides a trivial MIPS support the patch introduces new TargetInfo class
member getDefaultEntry() to override default name of the entry symbol.
MIPS uses __start for that.

Differential Revision:  http://reviews.llvm.org/D13227

llvm-svn: 248779
2015-09-29 05:34:03 +00:00