Commit Graph

9 Commits

Author SHA1 Message Date
Rafael Espindola 056190c348 Don't make _gp absolute.
_gp points to a position in the file, so it is not really absolute. It
is also simpler to not force it to be absolute, so if there is no
strong ABI requirement we should not do it.

llvm-svn: 313333
2017-09-15 01:49:01 +00:00
Simon Atanasyan 6a4eb75c46 [ELF][MIPS] Make _gp, _gp_disp, __gnu_local_gp global symbols
These MIPS specific symbols should be global because in general they can
have an arbitrary value. By default this value is a fixed offset from .got
section.

This patch adds more checks to the mips-gp-local.s test case but marks
it as XFAIL because LLD does not allow redefinition of absolute symbols
value by a linker script. This should be fixed by D27276.

Differential revision: https://reviews.llvm.org/D27524

llvm-svn: 289025
2016-12-08 06:19:47 +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 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 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
Simon Atanasyan 3a5b6e2750 [ELF][MIPS] Do not create dynamic relocations against _gp_disp symbol
MIPS _gp_disp designates offset between start of function and gp pointer
into GOT therefore any relocations against it do not require dynamic
relocation.

llvm-svn: 257492
2016-01-12 17:31:45 +00:00
Simon Atanasyan 49f98c742c [ELF][MIPS] Do not use 'sed' to modify binary files
On Windows different versions of 'sed' work in different text/binary
mode by default. If default mode is text, sed produces corrupted binary
files. Unfortunately there is no standard command line option to select
the mode. Some 'sed' support '-b' to switch to binary mode, while other
ones support '--text' option and does not have '-b' option at all.

llvm-svn: 257471
2016-01-12 12:38:43 +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