Commit Graph

2050 Commits

Author SHA1 Message Date
Simon Atanasyan 1e98e743b0 [ELF][MIPS] Add test case to check using GP0 value in relocation calculation. NFC.
llvm-svn: 266119
2016-04-12 20:37:00 +00:00
Rafael Espindola a161f02db2 Make a test a bit stronger.
We were not testing that we handle addends in here.

llvm-svn: 266076
2016-04-12 14:35:26 +00:00
Rafael Espindola 6f92e14ce2 Use DefinedSynthetic for _gp* symbols.
The test changes to put _gp* in the .got section matches what both bfd
and gold do.

llvm-svn: 266067
2016-04-12 13:26:51 +00:00
Rafael Espindola a22b082e46 Always create a .got on mips.
The _gp* family of symbols is defined as an offset in .got, and it is
not at all clear what should happen when .got is not defined.

This will allow some simplifications on how these symbols are handled.

llvm-svn: 266063
2016-04-12 13:21:13 +00:00
George Rimar f2638d4256 [ELF] Removed redundant llvm-mc call. NFC.
llvm-svn: 266059
2016-04-12 12:01:31 +00:00
Rafael Espindola 9b3f99e50f Devide _gp in the same spot as other mips symbols. NFC.
The test changes are just because of the symbol order.

llvm-svn: 266037
2016-04-12 02:24:43 +00:00
Rafael Espindola 03ef404e97 Simplify the creation of __rel[a]_iplt_{start,end}.
They can be regular DefinedSynthetic.

llvm-svn: 265981
2016-04-11 19:14:59 +00:00
Peter Collingbourne c98de13871 ELF: Set FDE count in .eh_frame_hdr correctly.
It is possible to have FDEs with duplicate PCs if ICF was able to merge
functions with FDEs, or if the input files for some reason contained duplicate
FDEs.  We previously weren't handling this correctly when producing the
contents of the .eh_frame_hdr section; we were dropping entries and leaving
null entries at the end of the section, which confused consumers of unwind
data, such as the backtrace() function.

Fix the bug by setting the FDE count to the number of FDEs actually emitted
into .eh_frame_hdr, rather than the number of FDEs in .eh_frame.

Differential Revision: http://reviews.llvm.org/D18911

llvm-svn: 265957
2016-04-11 16:40:08 +00:00
Peter Collingbourne 7cf73ec4c7 ELF: Implement basic support for module asm in bitcode files.
Differential Revision: http://reviews.llvm.org/D18872

llvm-svn: 265956
2016-04-11 16:39:43 +00:00
Simon Atanasyan 2615c3846f [ELF] Do not skip relocation scanning checking if the symbol gets dynamic COPY relocation already
It is possible that the same symbol referenced by two kinds of
relocations at the same time. The first type requires say GOT entry
creation, the second type requires dynamic copy relocation. For MIPS
targets they might be R_MIPS_GOT16 and R_MIPS_HI16 relocations. For X86
target they might be R_386_GOT32 and R_386_32 respectively.

Now LLD never creates GOT entry for a symbol if this symbol already has
related copy relocation. This patch solves this problem.

Differential Revision: http://reviews.llvm.org/D18862

llvm-svn: 265910
2016-04-10 21:48:55 +00:00
Rui Ueyama 029d89ee57 Fix another crash bug in --start-lib.
The previous fix didn't work for bitcode files. This patch fixes
the remaining issue.

llvm-svn: 265854
2016-04-08 21:38:22 +00:00
Rafael Espindola 1d56225e3c Add an interesting test case we already pass.
We had no tests for the interaction of relocations pointing to tail
merged strings.

llvm-svn: 265853
2016-04-08 21:33:04 +00:00
Rui Ueyama 1f492893ac Fix a crash bug in --start-lib.
Previously, Lazy symbols were created for undefined symbols even though
such symbols cannot be resolved by loading object files. This patch
fixes that bug.

llvm-svn: 265847
2016-04-08 20:49:31 +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
Rafael Espindola a15fb15b05 Don't lower the visibility because of shared symbols.
If a shared library has a protected symbol 'foo', that doesn't imply
that the symbol 'foo' in the output should be protected or not.

llvm-svn: 265794
2016-04-08 16:11:42 +00:00
Rafael Espindola b729b2131d Produce STV_DEFAULT for symbols in shared libraries.
The spec says:
If a symbol definition with STV_PROTECTED visibility from a shared
object is taken as resolving a reference from an executable or another
shared object, the SHN_UNDEF symbol table entry created has STV_DEFAULT
visibility.

llvm-svn: 265792
2016-04-08 15:43:43 +00:00
Adhemerval Zanella 15cba9e7e5 [lld] [ELF/AARCH64] Fix dynamic relocation from PIC GOT access
This patch fixes dynamic relocation creation from GOT access in dynamic
objects on aarch64. Current code creates a plt relative one
(R_AARCH64_JUMP_SLOT) instead of a got relative (R_AARCH64_GLOB_DAT).

It leads the programs fails with:

$ cat t.cc

std::string test = "hello...\n";

int main ()
{
  printf ("%s\n", test.c_str());
  return 0;
}
$ clang++ t.cc -fpic -o t
$ ./t
hello...

Segmentation fault (core dumped)

Due the fact it will try to access the plt instead of the got for
__cxa_atexit registration for the std::string destruction.  It will
lead in a bogus function address in atexit.

llvm-svn: 265784
2016-04-08 14:10:41 +00:00
Rui Ueyama d86ec30168 ELF: Add --build-id=sha1 option.
llvm-svn: 265748
2016-04-07 23:51:56 +00:00
Rui Ueyama 3a41be277a ELF: Implement --build-id=md5.
Previously, we supported only one hash function, FNV-1, so
BuildIdSection directly handled hash computation. In this patch,
I made BuildIdSection an abstract class and defined two subclasses,
BuildIdFnv1 and BuildIdMd5.

llvm-svn: 265737
2016-04-07 22:49:21 +00:00
Rui Ueyama c4354a3c18 ELF: Define -S as an alias for --strip-debug.
llvm-svn: 265723
2016-04-07 21:10:09 +00:00
Rui Ueyama fc6a4b045f ELF: Add --strip-debug option.
If --strip-debug option is given, then all sections whose names start
with ".debug" are removed from output.

llvm-svn: 265722
2016-04-07 21:04:51 +00:00
Rui Ueyama 8c76487ee5 ELF: Add --no-gnu-unique option.
When the option is specified, then all STB_GNU_UNIQUE symbols are
converted to STB_GLOBAL symbols.

llvm-svn: 265717
2016-04-07 20:41:41 +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 56004c577a Don't create dynamic relocs for discarded .eh_frame entries.
This requires knowing input section offsets in output sections before
scanRelocs. This is generally a good thing and should allow further
simplifications in the creation of dynamic relocations.

llvm-svn: 265673
2016-04-07 14:22:09 +00:00
Rafael Espindola 7231c3372f Add a test for the offset of dynamic relocations.
I found that a patch I am working on would have broken this and no
existing test found it.

llvm-svn: 265664
2016-04-07 12:02:42 +00:00
Rafael Espindola 1b6188d2f8 Make this test a bit stronger.
Show that in addition to handling empty .eh_frame, it is merged with any
regular .eh_frame.

llvm-svn: 265588
2016-04-06 19:38:26 +00:00
Ed Schouten 0a04b03ab2 Make TLS work for PIE executables on aarch64.
Similar to r265462, TLS related relocations aren't marked as relative,
meaning that we end up generating R_AARCH64_RELATIVE relocations for
them. This change adds TLS relocations that I've seen on my system. With
this patch applied CloudABI's unit testing binary now passes on aarch64.

Approved by:	ruiu
Differential Revision:	http://reviews.llvm.org/D18816

llvm-svn: 265575
2016-04-06 17:53:31 +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
George Rimar 2348320d4e [ELF] - Teach linkerscript error handler to show full script line and column marker on error.
When error, this adds the text line of script to the output
and a marks exact incorrect token under it:

line 1: <error text here>
UNKNOWN_TAG {
      ^

Differential revision: http://reviews.llvm.org/D18699

llvm-svn: 265523
2016-04-06 08:08:40 +00:00
Rafael Espindola f7085871fd Delete broken code.
A synthetic symbol can be global or local, and with the current
infrastructure we don't need any special code for it.

Fixes PR27228.

llvm-svn: 265478
2016-04-05 22:08:39 +00:00
Rafael Espindola 2d390b6c8b Add a test for relocations in non alloc sections.
We already got this right, but we were not testing it.

llvm-svn: 265471
2016-04-05 21:27:30 +00:00
Ed Schouten 639a333730 Make TLS work for PIE executables on x86-64.
While trying to get PIE work on CloudABI for x86-64, I noticed that even
though GNU ld would generate functional binaries, LLD would not. It
turns out that we generate relocations for referencing TLS objects
inside of the text segment, which shouldn't happen.

This change extends the isRelRelative() function to list some additional
relocation types that should be treated as relative. This makes my C
library unit testing binary work on x86-64.

Approved by:	ruiu
Differential Revision:	http://reviews.llvm.org/D18688
Fixes bug:	https://llvm.org/bugs/show_bug.cgi?id=27174

llvm-svn: 265462
2016-04-05 20:51:50 +00:00
Ed Schouten f2fdd013a2 Don't omit dynamic relocations for the GOT.
Where Clang's AArch64 backend seems to differ from the X86 backend is
that it tends to use the GOT more aggressively.

After getting CloudABI PIEs working on x86-64, I noticed that accessing
global variables would still crash on aarch64. Tracing it down, it turns
out that the GOT was filled with entries assuming the base address was
zero.

It turns out that we skip generating relocations for GOT entries in case
the relocation pointing towards the GOT is relative. Whether the thing
pointing to the GOT is absolute or relative shouldn't make any
difference; the GOT entry itself should contain the absolute address,
thus needs a relocation regardless.

Approved by:	rafael
Differential Revision:	http://reviews.llvm.org/D18739

llvm-svn: 265453
2016-04-05 20:17:33 +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 c393c028a9 Add triple to llvm-mc command line. Should fix Windows bot.
llvm-svn: 265373
2016-04-05 01:05:42 +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
Peter Collingbourne 4cdade6a2f ELF: Create dynamic symbols for symbol aliases of copy relocations.
For each copy relocation that we create, look through the DSO's symbol table
for aliases and create a dynamic symbol for each one. This causes the copy
relocation to correctly interpose any aliases.

Copy relocations are relatively uncommon (on my machine, 56% of binaries in
/usr/bin have no copy relocations probably due to being PIEs, 97% of them
have <10, and the binary with the largest number of them has 97) so it's
probably fine to do this in a relatively inefficient way.

Differential Revision: http://reviews.llvm.org/D18731

llvm-svn: 265354
2016-04-04 22:29:24 +00:00
Rui Ueyama d575edb780 Fix -disable-verify test.
This test didn't actually test the functionality. The new test
verifies that "-verify" is passed if and only if -disable-verify
is not given.

llvm-svn: 265316
2016-04-04 17:42:01 +00:00
Simon Atanasyan 38da8c3bac [ELF][MIPS] Extend test case to check LA25 stubs creation for STO_MIPS_PIC symbols. NFC.
The only way to get an object file with symbols marked by the STO_MIPS_PIC
flag is to link PIC and non-PIC object files and generate a relocatable
output using '-r' command line option. Now LLD is able to generate a relocatable
output but does not mark PIC symbols by the STO_MIPS_PIC flag. So I have
to use binary input mips-sto-pic.o generated by GNU BFD linker.

llvm-svn: 265310
2016-04-04 16:47:31 +00:00
Rafael Espindola c64119a9bf Regenerate test file.
It had been created with a lld version that was producing an invalid
sh_info.

llvm-svn: 265305
2016-04-04 16:02:39 +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 842fa53026 [LTO] Implement -disable-verify, which disables bitcode verification.
So, there are some cases when the IR Linker produces a broken
module (which doesn't pass the verifier) and we end up asserting
inside the verifier. I think it's always a bug producing a module
which does not pass the verifier but there are some cases in which
people can live with the broken module (e.g. if only DebugInfo
metadata are broken). The gold plugin has something similar.

This commit is motivated by a situation I found in the
wild. It seems that somebody else discovered it independently
and reported in PR24923.

llvm-svn: 265258
2016-04-03 03:39:09 +00:00
Davide Italiano 88dbd3b1cf [LTO] Add a test to ensure we reject negative opt level.
We already got this right, but it never hurts adding another
test, in case we'll change the handling in the future, to ensure
we don't break it.

llvm-svn: 265256
2016-04-03 03:12:00 +00:00
Davide Italiano 8848d44e46 [LTO] Reject invalid optimization levels.
llvm-svn: 265255
2016-04-03 02:41:15 +00:00
Davide Italiano 887d76c392 [LTO] Fix -save-temps in case -o is not specified.
Currently we create a file called .lto.bc. In UNIX,
ls(1) by default doesn't show up files starting with
a dot, as they're (only by convention) hidden.
This makes the output of -save-temps a little bit
hard to find. Use "a.out.lto.bc" instead if the
output file is not specified.

While here, change an existing -save-temps test to
exercise this more interesting behaviour.

llvm-svn: 265254
2016-04-03 02:16:56 +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
Sean Silva 8e4ad5dbf8 PR27104: Add -mllvm option
The argv[0] is based on the analogous thing in clang.

llvm-svn: 265206
2016-04-02 01:39:56 +00:00
Rafael Espindola 059f3fb8fb Don't create a plt when LD access is optimized.
llvm-svn: 265203
2016-04-02 00:19:22 +00:00
Rafael Espindola cf3b04dab9 Don't create a PLT when we optimize out the plt use.
llvm-svn: 265202
2016-04-01 23:36:56 +00:00
Rafael Espindola 2ee0092053 Don't apply a recolation that the dynamic linker will rewrite.
This matches the behavior of both bfd and gold. Looks like we just got
here for mips because of a bad ordering of an if else chain.

llvm-svn: 265147
2016-04-01 16:21:09 +00:00