[mips][micromips] Fix how values in .gcc_except_table are calculated
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
diff --git a/llvm/lib/MC/MCExpr.cpp b/llvm/lib/MC/MCExpr.cpp
index d8091e4..7ca935f 100644
--- a/llvm/lib/MC/MCExpr.cpp
+++ b/llvm/lib/MC/MCExpr.cpp
@@ -558,6 +558,11 @@
if (Asm->isThumbFunc(&SA))
Addend |= 1;
+ // If symbol is labeled as micromips, we set low-bit to ensure
+ // correct offset in .gcc_except_table
+ if (Asm->getBackend().isMicroMips(&SA))
+ Addend |= 1;
+
// Clear the symbol expr pointers to indicate we have folded these
// operands.
A = B = nullptr;