[ms-inline asm] Add a helper function, isMSAsmKeyword().

These require special handling, which we don't currently handle.  This is being
put in place to ensure we don't do invalid symbol table lookups or try to parse
invalid assembly.  The test cases just makes sure the latter isn't happening.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162050 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 74d1c59..5493e34 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2762,6 +2762,17 @@
   return Owned(NS);
 }
 
+// isMSAsmKeyword - Return true if this is an MS-style inline asm keyword. These
+// require special handling.
+static bool isMSAsmKeyword(StringRef Name) {
+  bool Ret = llvm::StringSwitch<bool>(Name)
+    .Cases("EVEN", "ALIGN", true) // Alignment directives.
+    .Cases("LENGTH", "SIZE", "TYPE", true) // Type and variable sizes.
+    .Case("_emit", true) // _emit Pseudoinstruction.
+    .Default(false);
+  return Ret;
+}
+
 static void patchMSAsmStrings(Sema &SemaRef, bool &IsSimple,
                               SourceLocation AsmLoc,
                               ArrayRef<Token> AsmToks,
@@ -2795,7 +2806,14 @@
     if (isNewAsm) {
       AsmRegs[NumAsmStrings].resize(AsmToks.size());
       AsmNames[NumAsmStrings].resize(AsmToks.size());
-      Asm = AsmToks[i].getIdentifierInfo()->getName().str();
+
+      StringRef Piece = AsmToks[i].getIdentifierInfo()->getName();
+      // MS-style inline asm keywords require special handling.
+      if (isMSAsmKeyword(Piece))
+        IsSimple = false;
+
+      // TODO: Verify this is a valid opcode.
+      Asm = Piece;
       continue;
     }
 
@@ -2834,6 +2852,13 @@
 
       IsSimple = false;
 
+      // MS-style inline asm keywords require special handling.
+      if (isMSAsmKeyword(Name)) {
+        IsSimple = false;
+        Asm += Name;
+        break;
+      }
+
       // FIXME: Why are we missing this segment register?
       if (Name == "fs") {
         Asm += Name;
diff --git a/test/CodeGen/ms-inline-asm.c b/test/CodeGen/ms-inline-asm.c
index 310fbd1..c140d60 100644
--- a/test/CodeGen/ms-inline-asm.c
+++ b/test/CodeGen/ms-inline-asm.c
@@ -98,3 +98,23 @@
 // CHECK: [[RET:%[a-zA-Z0-9]+]] = load i32* [[J]], align 4
 // CHECK: ret i32 [[RET]]
 }
+
+void t12(void) {
+  __asm EVEN
+  __asm ALIGN
+}
+
+void t13(void) {
+  __asm {
+    _emit 0x4A
+    _emit 0x43
+    _emit 0x4B
+  }
+}
+
+void t14(void) {
+  unsigned arr[10];
+  __asm LENGTH arr ; sizeof(arr)/sizeof(arr[0])
+  __asm SIZE arr   ; sizeof(arr)
+  __asm TYPE arr   ; sizeof(arr[0])
+}