Current code does not check that a register number is in the 0-31 range.
Sometimes the parser checks that later for some kinds of instructions,
but that leads to unclear / incorrect error messages like that:
% cat test.s
.text
lb $4, 8($32)
% llvm-mc test.s -triple=mips64-unknown-linux
test.s:2:10: error: expected memory with 16-bit signed offset
lb $4, 8($32)
^
Sometimes the parser just crashes:
% cat test.s
.text
lw $4, 8($32)
% llvm-mc test.s -triple=mips64-unknown-linux
This patch resolves the problem by checking that register number after
'$' sign is in the 0-31 range. If the number is out of the range the
parser shows the `invalid register number` error, but treats invalid
register number as a normal one to continue parsing and catch other
possible errors.
Differential Revision: https://reviews.llvm.org/D45919
llvm-svn: 330732
9df3be3ccb