[Microsoft][C++] Clang doesn't support a use of "this" pointer inside inline asm

Clang doesn’t support a use of “this” pointer inside inline asm.
When I tried to compile a class or a struct (see example) with an inline asm that contains "this" pointer.
Clang returns with an error.
This patch fixes that.

error: expected unqualified-id
For example:
'''
struct A {
    void f() {
          __asm mov eax, this
              // error: expected unqualified-id
                  }
};
'''
Differential Revision: http://reviews.llvm.org/D15115

llvm-svn: 255645

2 files changed, 18 insertions, 12 deletions

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index e125b805b25..cc4fa2ec597 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -1696,7 +1696,8 @@ llvm::Value* CodeGenFunction::EmitAsmInput(
   if (Info.allowsRegister() || !Info.allowsMemory())
     if (CodeGenFunction::hasScalarEvaluationKind(InputExpr->getType()))
       return EmitScalarExpr(InputExpr);
-
+  if (InputExpr->getStmtClass() == Expr::CXXThisExprClass)
+    return EmitScalarExpr(InputExpr);
   InputExpr = InputExpr->IgnoreParenNoopCasts(getContext());
   LValue Dest = EmitLValue(InputExpr);
   return EmitAsmInputLValue(Info, Dest, InputExpr->getType(), ConstraintStr,
diff --git a/clang/lib/Parse/ParseStmtAsm.cpp b/clang/lib/Parse/ParseStmtAsm.cpp
index d3281393f92..f469a064f89 100644
--- a/clang/lib/Parse/ParseStmtAsm.cpp
+++ b/clang/lib/Parse/ParseStmtAsm.cpp
@@ -215,17 +215,22 @@ ExprResult Parser::ParseMSAsmIdentifier(llvm::SmallVectorImpl<Token> &LineToks,
   // Require an identifier here.
   SourceLocation TemplateKWLoc;
   UnqualifiedId Id;
-  bool Invalid =
-      ParseUnqualifiedId(SS,
-                         /*EnteringContext=*/false,
-                         /*AllowDestructorName=*/false,
-                         /*AllowConstructorName=*/false,
-                         /*ObjectType=*/ParsedType(), TemplateKWLoc, Id);
-
-  // Perform the lookup.
-  ExprResult Result = Actions.LookupInlineAsmIdentifier(
-      SS, TemplateKWLoc, Id, Info, IsUnevaluatedContext);
-
+  bool Invalid = true;
+  ExprResult Result;
+  if (Tok.is(tok::kw_this)) {
+    Result = ParseCXXThis();
+    Invalid = false;
+  } else {
+    Invalid =
+        ParseUnqualifiedId(SS,
+                           /*EnteringContext=*/false,
+                           /*AllowDestructorName=*/false,
+                           /*AllowConstructorName=*/false,
+                           /*ObjectType=*/ParsedType(), TemplateKWLoc, Id);
+    // Perform the lookup.
+    Result = Actions.LookupInlineAsmIdentifier(SS, TemplateKWLoc, Id, Info,
+                                               IsUnevaluatedContext);
+  }
   // While the next two tokens are 'period' 'identifier', repeatedly parse it as
   // a field access. We have to avoid consuming assembler directives that look
   // like '.' 'else'.