[llvm] r251270 - [MC] Don't crash when .word is given bogus values

[David Majnemer via llvm-commits]

Author: majnemer
Date: Sun Oct 25 21:45:50 2015
New Revision: 251270

URL: http://llvm.org/viewvc/llvm-project?rev=251270&view=rev
Log:
[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.

Modified:
    llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
    llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp
    llvm/trunk/test/MC/AsmParser/exprs-invalid.s

Modified: llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp?rev=251270&r1=251269&r2=251270&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp Sun Oct 25 21:45:50 2015
@@ -1730,10 +1730,19 @@ bool PPCAsmParser::ParseDirectiveWord(un
   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;

Modified: llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp?rev=251270&r1=251269&r2=251270&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp (original)
+++ llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp Sun Oct 25 21:45:50 2015
@@ -2831,10 +2831,19 @@ bool X86AsmParser::ParseDirectiveWord(un
   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;

Modified: llvm/trunk/test/MC/AsmParser/exprs-invalid.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AsmParser/exprs-invalid.s?rev=251270&r1=251269&r2=251270&view=diff
==============================================================================
--- llvm/trunk/test/MC/AsmParser/exprs-invalid.s (original)
+++ llvm/trunk/test/MC/AsmParser/exprs-invalid.s Sun Oct 25 21:45:50 2015
@@ -12,3 +12,6 @@
 
 // CHECK-ERRORS: error: literal value out of range for directive
 .long 4e71cf69 // double floating point constant due to missing "0x"
+
+// CHECK-ERRORS: error: literal value out of range for directive
+.word 0xfffffffff