When compiling position-independent executables, we now use
DW_EH_PE_pcrel | DW_EH_PE_sdata4. However, the MIPS ABI does not define a
64-bit PC-relative ELF relocation so we cannot use sdata8 for the large
code model case. When using the large code model, we fall back to the
previous behaviour of generating absolute relocations.
With this change clang-generated .o files can be linked by LLD without
having to pass -Wl,-z,notext (which creates text relocations).
This is simpler than the approach used by ld.bfd, which rewrites the
.eh_frame section to convert absolute relocations into relative references.
I saw in D13104 that apparently ld.bfd did not accept pc-relative relocations
for MIPS ouput at some point. However, I also checked that recent ld.bfd
can process the clang-generated .o files so this no longer seems true.
Reviewed By: atanasyan
Differential Revision: https://reviews.llvm.org/D72228
When a landing pad is calculated in a program that is compiled for micromips
with -fPIC flag, it will point to an even address.
Such an error will cause a segmentation fault, as the instructions in
micromips are aligned on odd addresses. This patch sets the last bit of the
offset where a landing pad is, to 1, which will effectively be an odd
address and point to the instruction exactly.
r344591 fixed this issue for -static compilation.
Patch by Aleksandar Beserminji.
Differential Revision: https://reviews.llvm.org/D57677
llvm-svn: 353480
When compiling static executable for micromips, CFI symbols
are incorrectly labeled as MICROMIPS, which cause
".eh_frame_hdr refers to overlapping FDEs." error.
This patch does not label CFI symbols as MICROMIPS, and FDEs do not
overlap anymore. This patch also exposes another bug, which is fixed
here: https://reviews.llvm.org/D52985
Differential Revision: https://reviews.llvm.org/D52987
llvm-svn: 344516
When compiling static executable for micromips, CFI symbols
are incorrectly labeled as MICROMIPS, which cause
".eh_frame_hdr refers to overlapping FDEs." error.
This patch does not label CFI symbols as MICROMIPS, and FDEs do not
overlap anymore. This patch also exposes another bug, which is fixed
here: https://reviews.llvm.org/D52985
Differential Revision: https://reviews.llvm.org/D52987
llvm-svn: 344511
Elvina Yakubova