Commit Graph

6 Commits

Author SHA1 Message Date
Simon Atanasyan 7b8481bf95 [ELF][MIPS] Fix predicate used for sorting MIPS dynamic symbol tables
Now it conforms requirement for std::stable_sort predicates. That
resolves build-bot failures on Windows hosts.

llvm-svn: 273151
2016-06-20 11:37:56 +00:00
Simon Atanasyan 4132511cdc [ELF][MIPS] Support GOT entries for non-preemptible symbols with different addends
There are two motivations for this patch. The first one is a preparation
for support MIPS TLS relocations. It might sound like a joke but for GOT
entries related to TLS relocations MIPS ABI uses almost regular approach
with creation of dynamic relocations for each GOT enty etc. But we need
to separate these 'regular' TLS related entries from MIPS specific local
and global parts of GOT. ABI declare simple solution - all TLS related
entries allocated at the end of GOT after local/global parts. The second
motivation it to support GOT relocations for non-preemptible symbols
with addends. If we have more than one GOT relocations against symbol S
with different addends we need to create GOT entries for each unique
Symbol/Addend pairs.

So we store all MIPS GOT entries in separate containers. For non-preemptible
symbols we have to maintain two data structures. The first one is MipsLocal
vector. Each entry corresponds to the GOT entry from the 'local' part
of the GOT contains the symbol's address plus addend. The second one
is MipsLocalMap. It is a map from Symbol/Addend pair to the GOT index.

Differential Revision: http://reviews.llvm.org/D21297

llvm-svn: 273127
2016-06-19 21:39:37 +00:00
Peter Collingbourne 0a68cf50f8 ELF: Do not create copy relocations for references in writable sections.
They are unnecessary, as the dynamic loader can apply the original relocations
directly. This was also resulting in the creation of copy relocations in PIEs.

Differential Revision: http://reviews.llvm.org/D19089

llvm-svn: 266273
2016-04-14 01:48:11 +00:00
Simon Atanasyan 49bc69b9bb [ELF][MIPS] Enumerate absolute MIPS relocations in the isRelRelative
This commit does two related thing. At first, it enumerates supported
absolute MIPS relocations in the `MipsTargetInfo<ELFT>::isRelRelative`
method. In that case the code is shorter and the case switch does not
tend to grow. At second, it prevents R_MIPS_COPY and PLT creation for
relative relocations. For almost all relative MIPS relocations like
R_MIPS_PC19_S2, R_MIPS_PCHI16 etc it does not have a sence. The only
exception is R_MIPS_PC32. GNU linker creates a copy relocation or PLT
entry for it. But I could not find any real test case uses R_MIPS_PC32
with DSO defined symbol as a target. So for now I prefer to skip this
case to simplify the LLD code.

llvm-svn: 261822
2016-02-25 05:03:52 +00:00
Simon Atanasyan 2287dc3bf8 [ELF][MIPS] Add lazy relocation support for MIPS
The patch adds lazy relocation support for MIPS and R_MIPS_26 relocation
handing.

R_MIPS_26 relocation might require PLT entry creation. In that case it
is fully supported by the patch. But if the relocation target is a local
symbol we need to use a different expression to calculate the relocation
result. This case is not implemented yet because there is no method to
get know the kind of relocation target in the `relocateOne` routine.

Differential Revision: http://reviews.llvm.org/D16982

llvm-svn: 260424
2016-02-10 19:57:19 +00:00
Simon Atanasyan e1bfc2e793 [ELF][MIPS] Support R_MIPS_COPY relocation
Generate R_MIPS_COPY relocation for 'static' relocations against object
symbols defined in a shared libraries.

llvm-svn: 260083
2016-02-08 10:05:13 +00:00