Commit Graph

3 Commits

Author SHA1 Message Date
George Rimar da4f43a4b4 [llvm-mc] - Produce R_X86_64_PLT32 for "call/jmp foo".
For instructions like call foo and jmp foo patch changes
relocation produced from R_X86_64_PC32 to R_X86_64_PLT32.
Relocation can be used as a marker for 32-bit PC-relative branches.
Linker will reduce PLT32 relocation to PC32 if function is defined locally.

Differential revision: https://reviews.llvm.org/D43383

llvm-svn: 325569
2018-02-20 10:17:57 +00:00
Rafael Espindola 35d6189f0f Compute A-B when A or B is weak.
Similar to r235222, but for the weak symbol case.

In an "ideal" assembler/object format an expression would always refer to the
final value and A-B would only be computed from a section in the same
comdat as A and B with A and B strong.

Unfortunately that is not the case with debug info on ELF, so we need an
heuristic.  Since we need an heuristic, we may as well use the same one as
gas:

* call weak_sym : produces a relocation, even if in the same section.
* A - weak_sym and weak_sym -A: don't produce a relocation if we can
  compute it.

This fixes pr23272 and changes the fix of pr22815 to match what gas does.

llvm-svn: 235227
2015-04-17 21:15:17 +00:00
Rafael Espindola c9e7068cdd Don't be over eager in evaluating a subtraction with a weak symbol.
In a subtraction of the form A - B, if B is weak, there is no way to represent
that on ELF since all relocations add the value of a symbol.

llvm-svn: 233139
2015-03-24 23:48:44 +00:00