[MSVC] Fix for http://llvm.org/PR24132: __declspec(property): double invocations of foo() when compiling foo()->propertyName

[ABataev]

Summary

Removes extra codegen for base expression of MS property call

[ABataev]

Ping

[rnk]

lgtm

Thanks, sorry for the delay, EH was keeping me busy. =/

[ABataev]

I see, no problems, thanks!

Best regards,

Alexey Bataev

Software Engineer
Intel Compiler Team
Intel Corp.

lib/Sema/SemaPseudoObject.cpp

public:
    bool findAtIndexSetter();
 
    ExprResult buildGet() override;
    ExprResult buildSet(Expr *op, SourceLocation, bool) override;
  };
 
  class MSPropertyOpBuilder : public PseudoOpBuilder {
    MSPropertyRefExpr *RefExpr;
+   OpaqueValueExpr *InstanceBase;
 
  public:
    MSPropertyOpBuilder(Sema &S, MSPropertyRefExpr *refExpr) :
      PseudoOpBuilder(S, refExpr->getSourceRange().getBegin()),
-     RefExpr(refExpr) {}
+     RefExpr(refExpr), InstanceBase(nullptr) {}
 
    Expr *rebuildAndCaptureObject(Expr *) override;
    ExprResult buildGet() override;
    ExprResult buildSet(Expr *op, SourceLocation, bool) override;
  };
 }
 
 /// Capture the given expression in an OpaqueValueExpr.
ExprResult ObjCSubscriptOpBuilder::buildSet(Expr *op, SourceLocation opcLoc,
   return msg;
 }
 
 //===----------------------------------------------------------------------===//
 //  MSVC __declspec(property) references
 //===----------------------------------------------------------------------===//
 
 Expr *MSPropertyOpBuilder::rebuildAndCaptureObject(Expr *syntacticBase) {
-  Expr *NewBase = capture(RefExpr->getBaseExpr());
+  InstanceBase = capture(RefExpr->getBaseExpr());
 
   syntacticBase =
-    MSPropertyRefRebuilder(S, NewBase).rebuild(syntacticBase);
+    MSPropertyRefRebuilder(S, InstanceBase).rebuild(syntacticBase);
 
   return syntacticBase;
 }
 
 ExprResult MSPropertyOpBuilder::buildGet() {
   if (!RefExpr->getPropertyDecl()->hasGetter()) {
     S.Diag(RefExpr->getMemberLoc(), diag::err_no_accessor_for_property)
       << 0 /* getter */ << RefExpr->getPropertyDecl();
     return ExprError();
   }
 
   UnqualifiedId GetterName;
   IdentifierInfo *II = RefExpr->getPropertyDecl()->getGetterId();
   GetterName.setIdentifier(II, RefExpr->getMemberLoc());
   CXXScopeSpec SS;
   SS.Adopt(RefExpr->getQualifierLoc());
-  ExprResult GetterExpr = S.ActOnMemberAccessExpr(
-    S.getCurScope(), RefExpr->getBaseExpr(), SourceLocation(),
-    RefExpr->isArrow() ? tok::arrow : tok::period, SS, SourceLocation(),
-    GetterName, nullptr);
+  ExprResult GetterExpr =
+      S.ActOnMemberAccessExpr(S.getCurScope(), InstanceBase, SourceLocation(),
+                              RefExpr->isArrow() ? tok::arrow : tok::period, SS,
+                              SourceLocation(), GetterName, nullptr);
   if (GetterExpr.isInvalid()) {
     S.Diag(RefExpr->getMemberLoc(),
            diag::error_cannot_find_suitable_accessor) << 0 /* getter */
       << RefExpr->getPropertyDecl();
     return ExprError();
   }
 
   MultiExprArg ArgExprs;
if (!RefExpr->getPropertyDecl()->hasSetter()) {
     return ExprError();
   }
 
   UnqualifiedId SetterName;
   IdentifierInfo *II = RefExpr->getPropertyDecl()->getSetterId();
   SetterName.setIdentifier(II, RefExpr->getMemberLoc());
   CXXScopeSpec SS;
   SS.Adopt(RefExpr->getQualifierLoc());
-  ExprResult SetterExpr = S.ActOnMemberAccessExpr(
-    S.getCurScope(), RefExpr->getBaseExpr(), SourceLocation(),
-    RefExpr->isArrow() ? tok::arrow : tok::period, SS, SourceLocation(),
-    SetterName, nullptr);
+  ExprResult SetterExpr =
+      S.ActOnMemberAccessExpr(S.getCurScope(), InstanceBase, SourceLocation(),
+                              RefExpr->isArrow() ? tok::arrow : tok::period, SS,
+                              SourceLocation(), SetterName, nullptr);
   if (SetterExpr.isInvalid()) {
     S.Diag(RefExpr->getMemberLoc(),
            diag::error_cannot_find_suitable_accessor) << 1 /* setter */
       << RefExpr->getPropertyDecl();
     return ExprError();
   }
 
   SmallVector<Expr*, 1> ArgExprs;

test/CodeGenCXX/ms-property.cpp

+// RUN: %clang_cc1 -emit-llvm -triple=x86_64-pc-win32 -fms-compatibility %s -o - | FileCheck %s
+
+class Test1 {
+private:
+  int x_;
+
+public:
+  Test1(int x) : x_(x) {}
+  __declspec(property(get = get_x)) int X;
+  int get_x() const { return x_; }
+  static Test1 *GetTest1() { return new Test1(10); }
+};
+
+// CHECK-LABEL: main
+int main(int argc, char **argv) {
+  // CHECK: [[CALL:%.+]] = call %class.Test1* @"\01?GetTest1@Test1@@SAPEAV1@XZ"()
+  // CHECK-NEXT: call i32 @"\01?get_x@Test1@@QEBAHXZ"(%class.Test1* [[CALL]])
+  return Test1::GetTest1()->X;
+}