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| author | Rafael Espindola <rafael.espindola@gmail.com> | 2014-03-20 02:12:01 +0000 |
|---|---|---|
| committer | Rafael Espindola <rafael.espindola@gmail.com> | 2014-03-20 02:12:01 +0000 |
| commit | 7fadc0ea7df49f4fef7da3797ea382d9486cc259 (patch) | |
| tree | a240de0de7267b634fd4b36e1e7673f661941f53 /clang/lib/CodeGen/CodeGenFunction.cpp | |
| parent | 05c152b5d134a878ae8781d6fc3b8619f387c9de (diff) | |
| download | llvm-7fadc0ea7df49f4fef7da3797ea382d9486cc259.zip llvm-7fadc0ea7df49f4fef7da3797ea382d9486cc259.tar.gz llvm-7fadc0ea7df49f4fef7da3797ea382d9486cc259.tar.bz2 | |
Look through variables when computing relocations.
Given
bar = foo + 4
.long bar
MC would eat the 4. GNU as includes it in the relocation. The rule seems to be
that a variable that defines a symbol is used in the relocation and one that
does not define a symbol is evaluated and the result included in the relocation.
Fixing this unfortunately required some other changes:
* Since the variable is now evaluated, it would prevent the ELF writer from
noticing the weakref marker the elf streamer uses. This patch then replaces
that with a VariantKind in MCSymbolRefExpr.
* Using VariantKind then requires us to look past other VariantKind to see
.weakref bar,foo
call bar@PLT
doing this also fixes
zed = foo +2
call zed@PLT
so that is a good thing.
* Looking past VariantKind means that the relocation selection has to use
the fixup instead of the target.
This is a reboot of the previous fixes for MC. I will watch the sanitizer
buildbot and wait for a build before adding back the previous fixes.
llvm-svn: 204294
Diffstat (limited to 'clang/lib/CodeGen/CodeGenFunction.cpp')
0 files changed, 0 insertions, 0 deletions