Asm parser range checking on .<size> <value> directives.

For example, ".byte 256" would previously assert() when emitting an object
file. Now it generates a diagnostic that the literal value is out of range.

rdar://9686950


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134069 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 15 insertions, 3 deletions

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 7b62db2..db188f7 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -28,6 +28,7 @@
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/raw_ostream.h"
@@ -1612,13 +1613,18 @@ bool AsmParser::ParseDirectiveValue(unsigned Size) {
 
     for (;;) {
       const MCExpr *Value;
+      SMLoc ExprLoc = getLexer().getLoc();
       if (ParseExpression(Value))
         return true;
 
       // Special case constant expressions to match code generator.
-      if (const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(Value))
-        getStreamer().EmitIntValue(MCE->getValue(), Size, DEFAULT_ADDRSPACE);
-      else
+      if (const MCConstantExpr *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, DEFAULT_ADDRSPACE);
+      } else
         getStreamer().EmitValue(Value, Size, DEFAULT_ADDRSPACE);
 
       if (getLexer().is(AsmToken::EndOfStatement))
diff --git a/test/MC/AsmParser/exprs-invalid.s b/test/MC/AsmParser/exprs-invalid.s
index dc27d80..88b2a0a 100644
--- a/test/MC/AsmParser/exprs-invalid.s
+++ b/test/MC/AsmParser/exprs-invalid.s
@@ -6,3 +6,9 @@
 
 // CHECK-ERRORS: error: invalid hexadecimal number
 .long 80+0xzz
+
+// CHECK-ERRORS: error: literal value out of range for directive
+.byte 256
+
+// CHECK-ERRORS: error: literal value out of range for directive
+.long 4e71cf69 // double floating point constant due to missing "0x"