Don't allow MCStreamer::EmitIntValue to output 0-byte integers.
It makes no sense and can hide bugs. In particular, it lead
to left shift by 64 bits, which is an undefined behavior,
properly reported by UBSan.
llvm-svn: 216134
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index c01f3ac..aafc5e1 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -2612,7 +2612,8 @@
for (uint64_t i = 0, e = NumValues; i != e; ++i) {
getStreamer().EmitIntValue(FillExpr, NonZeroFillSize);
- getStreamer().EmitIntValue(0, FillSize - NonZeroFillSize);
+ if (NonZeroFillSize < FillSize)
+ getStreamer().EmitIntValue(0, FillSize - NonZeroFillSize);
}
return false;
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index e7ee9e4..914e337 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -72,7 +72,7 @@
/// EmitIntValue - Special case of EmitValue that avoids the client having to
/// pass in a MCExpr for constant integers.
void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
- assert(Size <= 8 && "Invalid size");
+ assert(1 <= Size && Size <= 8 && "Invalid size");
assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
"Invalid size");
char buf[8];