Index: llvm/trunk/lib/MC/MCExpr.cpp =================================================================== --- llvm/trunk/lib/MC/MCExpr.cpp +++ llvm/trunk/lib/MC/MCExpr.cpp @@ -739,7 +739,17 @@ 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; Index: llvm/trunk/test/MC/ELF/div-by-zero.s =================================================================== --- llvm/trunk/test/MC/ELF/div-by-zero.s +++ llvm/trunk/test/MC/ELF/div-by-zero.s @@ -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