MIR Parser: Report an error when parsing duplicate memory operand flags.

llvm-svn: 244240

lib/CodeGen/MIRParser/MIParser.cpp

@@ -1059,6 +1059,7 @@ bool MIParser::getUint64(uint64_t &Result) {
 }
 
 bool MIParser::parseMemoryOperandFlag(unsigned &Flags) {
+  const unsigned OldFlags = Flags;
   switch (Token.kind()) {
   case MIToken::kw_volatile:
     Flags |= MachineMemOperand::MOVolatile;
@@ -1069,11 +1070,14 @@ bool MIParser::parseMemoryOperandFlag(unsigned &Flags) {
   case MIToken::kw_invariant:
     Flags |= MachineMemOperand::MOInvariant;
     break;
-  // TODO: report an error when we specify the same flag more than once.
   // TODO: parse the target specific memory operand flags.
   default:
     llvm_unreachable("The current token should be a memory operand flag");
   }
+  if (OldFlags == Flags)
+    // We know that the same flag is specified more than once when the flags
+    // weren't modified.
+    return error("duplicate '" + Token.stringValue() + "' memory operand flag");
   lex();
   return false;
 }

test/CodeGen/MIR/X86/duplicate-memory-operand-flag.mir

@@ -0,0 +1,29 @@
+# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+
+--- |
+
+  define i32 @volatile_inc(i32* %x) {
+  entry:
+    %0 = load volatile i32, i32* %x
+    %1 = add i32 %0, 1
+    store volatile i32 %1, i32* %x
+    ret i32 %1
+  }
+
+...
+---
+name:            volatile_inc
+tracksRegLiveness: true
+liveins:
+  - { reg: '%rdi' }
+body:
+  - id:          0
+    name:        entry
+    liveins:     [ '%rdi' ]
+    instructions:
+# CHECK: [[@LINE+1]]:55: duplicate 'volatile' memory operand flag
+      - '%eax = MOV32rm %rdi, 1, _, 0, _ :: (volatile volatile load 4 from %ir.x)'
+      - '%eax = INC32r killed %eax, implicit-def dead %eflags'
+      - 'MOV32mr killed %rdi, 1, _, 0, _, %eax :: (volatile store 4 into %ir.x)'
+      - 'RETQ %eax'
+...