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[MC] Don't crash on division by zero. 

Differential Revision:	http://reviews.llvm.org/D12776

llvm-svn: 247471
This commit is contained in:
Davide Italiano 2015-09-11 20:47:35 +00:00
parent 84bf8a3bc4
commit 63cee81c3c
2 changed files with 17 additions and 1 deletions
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12
llvm/lib/MC/MCExpr.cpp
View File

@ -739,7 +739,17 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
case MCBinaryExpr::Add: Result = LHS + RHS; break;
case MCBinaryExpr::And: Result = LHS & RHS; break;
case MCBinaryExpr::Div: Result = LHS / RHS; break;
case MCBinaryExpr::Div: {
// Handle division by zero. gas just emits a warning and keeps going,
// we try to be stricter.
// FIXME: Currently the caller of this function has no way to understand
// we're bailing out because of 'division by zero'. Therefore, it will
// emit a 'expected relocatable expression' error. It would be nice to
// change this code to emit a better diagnostic.
if (RHS == 0)
return false;
Result = LHS / RHS; break;
}
case MCBinaryExpr::EQ: Result = LHS == RHS; break;
case MCBinaryExpr::GT: Result = LHS > RHS; break;
case MCBinaryExpr::GTE: Result = LHS >= RHS; break;

6
llvm/test/MC/ELF/div-by-zero.s Normal file
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@ -0,0 +1,6 @@
// Check that llvm-mc doesn't crash on division by zero.
// RUN: not llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s 2> %t
// RUN: FileCheck -input-file %t %s
// CHECK: expected relocatable expression
.int 1/0