Patch to improve ir-gen for constructors with default argument

expressions and a test case.

llvm-svn: 78213

clang/lib/Sema/Sema.h

@@ -1672,6 +1672,14 @@ public:
                                     CXXConstructorDecl *Constructor,
                                     QualType DeclInitType, 
                                     Expr **Exprs, unsigned NumExprs);
+  
+  /// BuildCXXConstructExpr - Creates a complete call to a constructor,
+  /// including handling of its default argument expressions.
+  Expr * BuildCXXConstructExpr(ASTContext &C,
+                               QualType DeclInitType,
+                               CXXConstructorDecl *Constructor,
+                               bool Elidable,
+                               Expr **Exprs, unsigned NumExprs);
 
   /// FinalizeVarWithDestructor - Prepare for calling destructor on the
   /// constructed variable.

clang/lib/Sema/SemaDeclCXX.cpp

@@ -2356,13 +2356,16 @@ void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
   CopyConstructor->setUsed();
 }
 
-void Sema::InitializeVarWithConstructor(VarDecl *VD, 
-                                        CXXConstructorDecl *Constructor,
-                                        QualType DeclInitType, 
-                                        Expr **Exprs, unsigned NumExprs) {
-  CXXConstructExpr *Temp = CXXConstructExpr::Create(Context, DeclInitType, 
+/// BuildCXXConstructExpr - Creates a complete call to a constructor,
+/// including handling of its default argument expressions.
+Expr *Sema::BuildCXXConstructExpr(ASTContext &C,
+                                  QualType DeclInitType, 
+                                  CXXConstructorDecl *Constructor,
+                                  bool Elidable,
+                                  Expr **Exprs, unsigned NumExprs) {
+  CXXConstructExpr *Temp = CXXConstructExpr::Create(C, DeclInitType, 
                                                     Constructor, 
-                                                    false, Exprs, NumExprs);
+                                                    Elidable, Exprs, NumExprs);
   // default arguments must be added to constructor call expression.
   FunctionDecl *FDecl = cast<FunctionDecl>(Constructor);
   unsigned NumArgsInProto = FDecl->param_size();
@@ -2379,10 +2382,19 @@ void Sema::InitializeVarWithConstructor(VarDecl *VD,
       for (unsigned I = 0, N = E->getNumTemporaries(); I != N; ++I)
         ExprTemporaries.push_back(E->getTemporary(I));
     }
-    Expr *Arg = new (Context) CXXDefaultArgExpr(FDecl->getParamDecl(j));
+    Expr *Arg = new (C) CXXDefaultArgExpr(FDecl->getParamDecl(j));
     Temp->setArg(j, Arg);
   }
-  
+  return Temp;
+}
+
+void Sema::InitializeVarWithConstructor(VarDecl *VD, 
+                                        CXXConstructorDecl *Constructor,
+                                        QualType DeclInitType, 
+                                        Expr **Exprs, unsigned NumExprs) {
+  Expr *Temp = BuildCXXConstructExpr(Context,
+                                     DeclInitType, Constructor, 
+                                     false, Exprs, NumExprs);  
   MarkDeclarationReferenced(VD->getLocation(), Constructor);
   VD->setInit(Context, Temp);
 }

clang/lib/Sema/SemaExprCXX.cpp

@@ -911,8 +911,8 @@ Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
     assert(!ToType->isReferenceType());
     
     // FIXME: Keep track of whether the copy constructor is elidable or not.
-    From = CXXConstructExpr::Create(Context, ToType, 
-                                    SCS.CopyConstructor, false, &From, 1);
+    From = BuildCXXConstructExpr(Context,
+                                 ToType, SCS.CopyConstructor, false, &From, 1);
     return false;
   }
 

clang/lib/Sema/SemaInit.cpp

@@ -177,8 +177,8 @@ bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType,
         if (!Constructor)
           return true;
         
-        Init = CXXConstructExpr::Create(Context, DeclType, Constructor, false, 
-                                        &Init, 1);
+        Init = BuildCXXConstructExpr(Context,
+                                     DeclType, Constructor, false, &Init, 1);
         return false;
       }
       

clang/lib/Sema/SemaTemplateInstantiateExpr.cpp

@@ -1073,11 +1073,11 @@ TemplateExprInstantiator::VisitCXXConstructExpr(CXXConstructExpr *E) {
     Args.push_back(ArgInst.takeAs<Expr>());
   }
 
-  return SemaRef.Owned(CXXConstructExpr::Create(SemaRef.Context, T,
-                                                E->getConstructor(), 
-                                                E->isElidable(),
-                                                Args.takeAs<Expr>(), 
-                                                Args.size()));
+  return SemaRef.Owned(SemaRef.BuildCXXConstructExpr(SemaRef.Context, T,
+                                             E->getConstructor(), 
+                                             E->isElidable(),
+                                             Args.takeAs<Expr>(), 
+                                             Args.size()));
 }
 
 Sema::OwningExprResult 

clang/test/CodeGenCXX/constructor-default-arg.cpp

@@ -0,0 +1,30 @@
+// RUN: clang-cc %s -emit-llvm -o %t &&
+// RUN: grep 'call void @_ZN1XC1ERK1Xiii' %t | count 3
+
+extern "C" int printf(...);
+
+
+struct C {
+	C() : iC(6) {}
+	int iC;
+};
+
+int foo() {
+  return 6;
+};
+
+class X { // ...
+public: 
+	X(int) {}
+	X(const X&, int i = 1, int j = 2, int k = foo()) {
+		printf("X(const X&, %d, %d, %d)\n", i, j, k);
+	}
+};
+
+int main()
+{
+	X a(1);
+	X b(a, 2);
+	X c = b;
+	X d(a, 5, 6);
+}