[MC] Don't crash when .word is given bogus values

We didn't validate that the .word directive was given a sane value,
leading to crashes when we attempt to write out the object file.

Instead, perform some validation and issue a diagnostic pointing at the
start of the diagnostic.

llvm-svn: 251270

1 files changed, 10 insertions, 1 deletions

diff --git a/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp b/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
index 1ad3d07831a..85d3fa39181 100644
--- a/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
+++ b/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
@@ -1730,10 +1730,19 @@ bool PPCAsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
   if (getLexer().isNot(AsmToken::EndOfStatement)) {
     for (;;) {
       const MCExpr *Value;
+      SMLoc ExprLoc = getLexer().getLoc();
       if (getParser().parseExpression(Value))
         return false;
 
-      getParser().getStreamer().EmitValue(Value, Size);
+      if (const auto *MCE = dyn_cast<MCConstantExpr>(Value)) {
+        assert(Size <= 8 && "Invalid size");
+        uint64_t IntValue = MCE->getValue();
+        if (!isUIntN(8 * Size, IntValue) && !isIntN(8 * Size, IntValue))
+          return Error(ExprLoc, "literal value out of range for directive");
+        getStreamer().EmitIntValue(IntValue, Size);
+      } else {
+        getStreamer().EmitValue(Value, Size, ExprLoc);
+      }
 
       if (getLexer().is(AsmToken::EndOfStatement))
         break;