Switch more of Sema::CheckInitializerTypes over to

InitializationSequence. Specially, switch initialization of a C++
class type (either copy- or direct-initialization). 

Also, make sure that we create an elidable copy-construction when
performing copy initialization of a C++ class variable. Fixes PR5826.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91750 91177308-0d34-0410-b5e6-96231b3b80d8

16 files changed, 106 insertions, 118 deletions

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index b9c1897a1e..b2ff5ee105 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -578,14 +578,14 @@ def warn_field_is_uninit : Warning<"field is uninitialized when used here">,
   InGroup<DiagGroup<"uninitialized">>;
 
 def err_temp_copy_no_viable : Error<
-  "no viable copy constructor %select{throwing|returning}0 object of type %1">;
+  "no viable copy constructor %select{copying variable|copying parameter|"
+  "returning object|throwing object}0 of type %1">;
 def err_temp_copy_ambiguous : Error<
-  "ambiguous copy constructor call when %select{throwing|returning}0 object of "
-  "type %1">;
+  "ambiguous copy constructor call when %select{copying variable|copying "
+  "parameter|returning object|throwing object}0 of type %1">;
 def err_temp_copy_deleted : Error<
-  "%select{throwing|returning}0 object of type %1 invokes deleted copy "
-  "constructor">;
-  
+  "%select{copying variable|copying parameter|returning object|throwing "
+  "object}0 of type %1 invokes deleted copy constructor">;
   
 // C++0x decltype
 def err_cannot_determine_declared_type_of_overloaded_function : Error<
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 60de672c0a..6f11a87d11 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -222,79 +222,15 @@ bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType,
     //   -- If the destination type is a (possibly cv-qualified) class
     //      type:
     if (getLangOptions().CPlusPlus && DeclType->isRecordType()) {
-      QualType DeclTypeC = Context.getCanonicalType(DeclType);
-      QualType InitTypeC = Context.getCanonicalType(Init->getType());
-
-      //   -- If the initialization is direct-initialization, or if it is
-      //      copy-initialization where the cv-unqualified version of the
-      //      source type is the same class as, or a derived class of, the
-      //      class of the destination, constructors are considered.
-      if ((DeclTypeC.getLocalUnqualifiedType() 
-                                     == InitTypeC.getLocalUnqualifiedType()) ||
-          IsDerivedFrom(InitTypeC, DeclTypeC)) {
-        const CXXRecordDecl *RD =
-          cast<CXXRecordDecl>(DeclType->getAs<RecordType>()->getDecl());
-
-        // No need to make a CXXConstructExpr if both the ctor and dtor are
-        // trivial.
-        if (RD->hasTrivialConstructor() && RD->hasTrivialDestructor())
-          return false;
-
-        ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
-
-        // FIXME: Poor location information
-        InitializationKind InitKind
-          = InitializationKind::CreateCopy(Init->getLocStart(), 
-                                           SourceLocation());
-        if (DirectInit)
-          InitKind = InitializationKind::CreateDirect(Init->getLocStart(),
-                                                      SourceLocation(), 
-                                                      SourceLocation());
-        CXXConstructorDecl *Constructor
-          = PerformInitializationByConstructor(DeclType, 
-                                               MultiExprArg(*this, 
-                                                            (void **)&Init, 1),
-                                               InitLoc, Init->getSourceRange(),
-                                               InitEntity, InitKind,
-                                               ConstructorArgs);
-        if (!Constructor)
-          return true;
-
-        OwningExprResult InitResult =
-          BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(),
-                                DeclType, Constructor,
-                                move_arg(ConstructorArgs));
-        if (InitResult.isInvalid())
-          return true;
-
-        Init = InitResult.takeAs<Expr>();
-        return false;
-      }
+      InitializationSequence InitSeq(*this, Entity, Kind, &Init, 1);
+      OwningExprResult CurInit = InitSeq.Perform(*this, Entity, Kind,
+                                          MultiExprArg(*this, (void**)&Init, 1),
+                                                 &DeclType);
+      if (CurInit.isInvalid())
+        return true;
 
-      //   -- Otherwise (i.e., for the remaining copy-initialization
-      //      cases), user-defined conversion sequences that can
-      //      convert from the source type to the destination type or
-      //      (when a conversion function is used) to a derived class
-      //      thereof are enumerated as described in 13.3.1.4, and the
-      //      best one is chosen through overload resolution
-      //      (13.3). If the conversion cannot be done or is
-      //      ambiguous, the initialization is ill-formed. The
-      //      function selected is called with the initializer
-      //      expression as its argument; if the function is a
-      //      constructor, the call initializes a temporary of the
-      //      destination type.
-      // FIXME: We're pretending to do copy elision here; return to this when we
-      // have ASTs for such things.
-      if (!PerformImplicitConversion(Init, DeclType, Sema::AA_Initializing))
-        return false;
-
-      if (InitEntity)
-        return Diag(InitLoc, diag::err_cannot_initialize_decl)
-          << InitEntity << (int)(Init->isLvalue(Context) == Expr::LV_Valid)
-          << Init->getType() << Init->getSourceRange();
-      return Diag(InitLoc, diag::err_cannot_initialize_decl_noname)
-        << DeclType << (int)(Init->isLvalue(Context) == Expr::LV_Valid)
-        << Init->getType() << Init->getSourceRange();
+      Init = CurInit.takeAs<Expr>();
+      return false;
     }
 
     // C99 6.7.8p16.
@@ -2014,6 +1950,26 @@ DeclarationName InitializedEntity::getName() const {
   return DeclarationName();
 }
 
+DeclaratorDecl *InitializedEntity::getDecl() const {
+  switch (getKind()) {
+  case EK_Variable:
+  case EK_Parameter:
+  case EK_Member:
+    return VariableOrMember;
+
+  case EK_Result:
+  case EK_Exception:
+  case EK_New:
+  case EK_Temporary:
+  case EK_Base:
+  case EK_ArrayOrVectorElement:
+    return 0;
+  }
+  
+  // Silence GCC warning
+  return 0;
+}
+
 //===----------------------------------------------------------------------===//
 // Initialization sequence
 //===----------------------------------------------------------------------===//
@@ -3051,25 +3007,32 @@ static bool shouldBindAsTemporary(const InitializedEntity &Entity,
 /// thrown), make the copy. 
 static Sema::OwningExprResult CopyIfRequiredForEntity(Sema &S,
                                             const InitializedEntity &Entity,
+                                             const InitializationKind &Kind,
                                              Sema::OwningExprResult CurInit) {
   SourceLocation Loc;
-  bool isReturn = false;
   
   switch (Entity.getKind()) {
   case InitializedEntity::EK_Result:
     if (Entity.getType().getType()->isReferenceType())
       return move(CurInit);
-    isReturn = true;
     Loc = Entity.getReturnLoc();
     break;
       
   case InitializedEntity::EK_Exception:
-    isReturn = false;
     Loc = Entity.getThrowLoc();
     break;
     
   case InitializedEntity::EK_Variable:
+    if (Entity.getType().getType()->isReferenceType() ||
+        Kind.getKind() != InitializationKind::IK_Copy)
+      return move(CurInit);
+    Loc = Entity.getDecl()->getLocation();
+    break;
+
   case InitializedEntity::EK_Parameter:
+    // FIXME: Do we need this initialization for a parameter?
+    return move(CurInit);
+
   case InitializedEntity::EK_New:
   case InitializedEntity::EK_Temporary:
   case InitializedEntity::EK_Base:
@@ -3110,21 +3073,21 @@ static Sema::OwningExprResult CopyIfRequiredForEntity(Sema &S,
       
   case OR_No_Viable_Function:
     S.Diag(Loc, diag::err_temp_copy_no_viable)
-      << isReturn << CurInitExpr->getType()
+      << (int)Entity.getKind() << CurInitExpr->getType()
       << CurInitExpr->getSourceRange();
     S.PrintOverloadCandidates(CandidateSet, false);
     return S.ExprError();
       
   case OR_Ambiguous:
     S.Diag(Loc, diag::err_temp_copy_ambiguous)
-      << isReturn << CurInitExpr->getType()
+      << (int)Entity.getKind() << CurInitExpr->getType()
       << CurInitExpr->getSourceRange();
     S.PrintOverloadCandidates(CandidateSet, true);
     return S.ExprError();
     
   case OR_Deleted:
     S.Diag(Loc, diag::err_temp_copy_deleted)
-      << isReturn << CurInitExpr->getType()
+      << (int)Entity.getKind() << CurInitExpr->getType()
       << CurInitExpr->getSourceRange();
     S.Diag(Best->Function->getLocation(), diag::note_unavailable_here)
       << Best->Function->isDeleted();
@@ -3364,7 +3327,7 @@ InitializationSequence::Perform(Sema &S,
                                                          false));
       
       if (!IsCopy)
-        CurInit = CopyIfRequiredForEntity(S, Entity, move(CurInit));
+        CurInit = CopyIfRequiredForEntity(S, Entity, Kind, move(CurInit));
       break;
     }
         
@@ -3425,7 +3388,7 @@ InitializationSequence::Perform(Sema &S,
         CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>());
       
       if (!Elidable)
-        CurInit = CopyIfRequiredForEntity(S, Entity, move(CurInit));
+        CurInit = CopyIfRequiredForEntity(S, Entity, Kind, move(CurInit));
       break;
     }
         
diff --git a/lib/Sema/SemaInit.h b/lib/Sema/SemaInit.h
index c42badd3f8..1987ad0734 100644
--- a/lib/Sema/SemaInit.h
+++ b/lib/Sema/SemaInit.h
@@ -195,7 +195,11 @@ public:
   
   /// \brief Retrieve the name of the entity being initialized.
   DeclarationName getName() const;
-  
+
+  /// \brief Retrieve the variable, parameter, or field being
+  /// initialized.
+  DeclaratorDecl *getDecl() const;
+
   /// \brief Determine the location of the 'return' keyword when initializing
   /// the result of a function call.
   SourceLocation getReturnLoc() const {
diff --git a/test/CXX/temp/temp.decls/temp.class/temp.static/p1-inst.cpp b/test/CXX/temp/temp.decls/temp.class/temp.static/p1-inst.cpp
index d02e5f3e57..aa53ebc580 100644
--- a/test/CXX/temp/temp.decls/temp.class/temp.static/p1-inst.cpp
+++ b/test/CXX/temp/temp.decls/temp.class/temp.static/p1-inst.cpp
@@ -8,13 +8,13 @@ struct X {
 };
 
 template<typename T> 
-  T X<T>::value = 17; // expected-error{{initialize}}
+  T X<T>::value = 17; // expected-error{{no viable conversion}}
 
 struct InitOkay {
   InitOkay(int) { }
 };
 
-struct CannotInit { };
+struct CannotInit { }; // expected-note{{candidate function}}
 
 int &returnInt() { return X<int>::value; }
 float &returnFloat() { return X<float>::value; }
diff --git a/test/CXX/temp/temp.decls/temp.class/temp.static/p1.cpp b/test/CXX/temp/temp.decls/temp.class/temp.static/p1.cpp
index 58479cda26..3cefeb821e 100644
--- a/test/CXX/temp/temp.decls/temp.class/temp.static/p1.cpp
+++ b/test/CXX/temp/temp.decls/temp.class/temp.static/p1.cpp
@@ -6,13 +6,13 @@ struct X0 {
 };
 
 template<typename T>
-T X0<T>::value = 0; // expected-error{{initialize}}
+T X0<T>::value = 0; // expected-error{{no viable conversion}}
 
 struct X1 { 
   X1(int);
 };
 
-struct X2 { };
+struct X2 { }; // expected-note{{candidate function}}
 
 int& get_int() { return X0<int>::value; }
 X1& get_X1() { return X0<X1>::value; }
diff --git a/test/CXX/temp/temp.param/p3.cpp b/test/CXX/temp/temp.param/p3.cpp
index 7576aae478..67d648ea97 100644
--- a/test/CXX/temp/temp.param/p3.cpp
+++ b/test/CXX/temp/temp.param/p3.cpp
@@ -15,7 +15,7 @@ template<template<class T> class Y> struct X1 {
 // could be interpreted as either a non-type template-parameter or a
 // type-parameter (because its identifier is the name of an already
 // existing class) is taken as a type-parameter. For example, 
-class T { /* ... */ }; 
+class T { /* ... */ };  // expected-note{{candidate function}}
 int i; 
 
 template<class T, T i> struct X2 {
@@ -23,6 +23,6 @@ template<class T, T i> struct X2 {
   { 
     T t1 = i; //template-parameters T and i 
     ::T t2 = ::i; // global namespace members T and i  \
-    // expected-error{{cannot initialize}}
+    // expected-error{{no viable conversion}}
   } 
 };
diff --git a/test/CodeGenCXX/constructor-init.cpp b/test/CodeGenCXX/constructor-init.cpp
index ae6014fc66..a0a35fa16f 100644
--- a/test/CodeGenCXX/constructor-init.cpp
+++ b/test/CodeGenCXX/constructor-init.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -emit-llvm -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -emit-llvm -o - | FileCheck %s
 
 extern "C" int printf(...);
 
@@ -59,3 +59,24 @@ int main() {
   n1.PR();
 }
 
+// PR5826
+template <class T> struct A {
+  A() {}
+  A(int) {}
+  A(const A&) {}
+  ~A() {}
+  operator int() {return 0;}
+};
+
+// CHECK: define void @_Z1fv()
+void f() {
+  // CHECK: call void @_ZN1AIsEC1Ei
+  A<short> a4 = 97;
+
+  // CHECK-NEXT: store i32 17
+  int i = 17;
+
+  // CHECK-NEXT: call void @_ZN1AIsED1Ev
+  // CHECK-NOT: call void @_ZN1AIsED1Ev
+  // CHECK: ret void
+}
diff --git a/test/SemaCXX/condition.cpp b/test/SemaCXX/condition.cpp
index 7a51f7e096..aede25e3f7 100644
--- a/test/SemaCXX/condition.cpp
+++ b/test/SemaCXX/condition.cpp
@@ -16,8 +16,8 @@ void test() {
   for (;s;) ; // expected-error {{value of type 'struct S' is not contextually convertible to 'bool'}}
   switch (s) {} // expected-error {{statement requires expression of integer type ('struct S' invalid)}}
 
-  while (struct S {} x=0) ; // expected-error {{types may not be defined in conditions}} expected-error {{cannot initialize 'x' with an rvalue of type 'int'}} expected-error {{value of type 'struct S' is not contextually convertible to 'bool'}}
-  while (struct {} x=0) ; // expected-error {{types may not be defined in conditions}} expected-error {{cannot initialize 'x' with an rvalue of type 'int'}} expected-error {{value of type 'struct <anonymous>' is not contextually convertible to 'bool'}}
+  while (struct S {} x=0) ; // expected-error {{types may not be defined in conditions}} expected-error {{no viable conversion}} expected-error {{value of type 'struct S' is not contextually convertible to 'bool'}} expected-note{{candidate function}}
+  while (struct {} x=0) ; // expected-error {{types may not be defined in conditions}} expected-error {{no viable conversion}} expected-error {{value of type 'struct <anonymous>' is not contextually convertible to 'bool'}} expected-note{{candidate function}}
   switch (enum {E} x=0) ; // expected-error {{types may not be defined in conditions}} expected-error {{incompatible type}}
 
   if (int x=0) { // expected-note 2 {{previous definition is here}}
diff --git a/test/SemaCXX/conversion-function.cpp b/test/SemaCXX/conversion-function.cpp
index fca5a4a72a..db322f4a3d 100644
--- a/test/SemaCXX/conversion-function.cpp
+++ b/test/SemaCXX/conversion-function.cpp
@@ -56,14 +56,14 @@ public:
 
 // This used to crash Clang.
 struct Flip;
-struct Flop {
+struct Flop { // expected-note{{candidate function}}
   Flop();
-  Flop(const Flip&);
+  Flop(const Flip&); // expected-note{{candidate function}}
 };
 struct Flip {
-  operator Flop() const;
+  operator Flop() const; // expected-note{{candidate function}}
 };
-Flop flop = Flip(); // expected-error {{cannot initialize 'flop' with an rvalue of type 'struct Flip'}}
+Flop flop = Flip(); // expected-error {{conversion from 'struct Flip' to 'struct Flop' is ambiguous}}
 
 // This tests that we don't add the second conversion declaration to the list of user conversions
 struct C {
diff --git a/test/SemaCXX/converting-constructor.cpp b/test/SemaCXX/converting-constructor.cpp
index e0e614ebe5..e78798b82c 100644
--- a/test/SemaCXX/converting-constructor.cpp
+++ b/test/SemaCXX/converting-constructor.cpp
@@ -27,7 +27,7 @@ public:
   FromShort(short s);
 };
 
-class FromShortExplicitly {
+class FromShortExplicitly { // expected-note{{candidate function}}
 public:
   explicit FromShortExplicitly(short s);
 };
@@ -36,7 +36,7 @@ void explicit_constructor(short s) {
   FromShort fs1(s);
   FromShort fs2 = s;
   FromShortExplicitly fse1(s);
-  FromShortExplicitly fse2 = s; // expected-error{{error: cannot initialize 'fse2' with an lvalue of type 'short'}}
+  FromShortExplicitly fse2 = s; // expected-error{{no viable conversion}}
 }
 
 // PR5519
diff --git a/test/SemaCXX/copy-initialization.cpp b/test/SemaCXX/copy-initialization.cpp
index 8df0c6340f..ad149232a4 100644
--- a/test/SemaCXX/copy-initialization.cpp
+++ b/test/SemaCXX/copy-initialization.cpp
@@ -2,17 +2,17 @@
 class X {
 public:
   explicit X(const X&);
-  X(int*); // expected-note{{candidate function}}
+  X(int*); // expected-note 2{{candidate function}}
   explicit X(float*);
 };
 
 class Y : public X { };
 
 void f(Y y, int *ip, float *fp) {
-  X x1 = y; // expected-error{{no matching constructor for initialization of 'x1'; candidate is:}}
+  X x1 = y; // expected-error{{no matching constructor for initialization of 'class X'}}
   X x2 = 0;
   X x3 = ip;
-  X x4 = fp; // expected-error{{cannot initialize 'x4' with an lvalue of type 'float *'}}
+  X x4 = fp; // expected-error{{no viable conversion}}
 }
 
 struct foo {
diff --git a/test/SemaCXX/dcl_init_aggr.cpp b/test/SemaCXX/dcl_init_aggr.cpp
index f7dc8f11c7..98aa7218f5 100644
--- a/test/SemaCXX/dcl_init_aggr.cpp
+++ b/test/SemaCXX/dcl_init_aggr.cpp
@@ -115,9 +115,9 @@ B2 b2_2 = { 4, d2, 0 };
 B2 b2_3 = { c2, a2, a2 };
 
 // C++ [dcl.init.aggr]p15:
-union u { int a; char* b; };
+union u { int a; char* b; }; // expected-note{{candidate function}}
 u u1 = { 1 }; 
 u u2 = u1; 
-u u3 = 1; // expected-error{{cannot initialize 'u3' with an rvalue of type 'int'}}
+u u3 = 1; // expected-error{{no viable conversion}}
 u u4 = { 0, "asdf" };  // expected-error{{excess elements in union initializer}}
 u u5 = { "asdf" }; // expected-error{{incompatible type initializing 'char const [5]', expected 'int'}}
diff --git a/test/SemaCXX/default1.cpp b/test/SemaCXX/default1.cpp
index 497a6b10ac..eab54f47b9 100644
--- a/test/SemaCXX/default1.cpp
+++ b/test/SemaCXX/default1.cpp
@@ -22,10 +22,10 @@ struct X {
 
 void j(X x = 17);
 
-struct Y {
+struct Y { // expected-note 2{{candidate}}
   explicit Y(int);
 };
 
-void k(Y y = 17); // expected-error{{cannot initialize 'y' with an rvalue of type 'int'}}
+void k(Y y = 17); // expected-error{{no viable conversion}}
 
-void kk(Y = 17); // expected-error{{cannot initialize a value of type 'struct Y' with an rvalue of type 'int'}}
+void kk(Y = 17); // expected-error{{no viable conversion}}
diff --git a/test/SemaCXX/nested-name-spec.cpp b/test/SemaCXX/nested-name-spec.cpp
index dc8eda5994..454af5ef19 100644
--- a/test/SemaCXX/nested-name-spec.cpp
+++ b/test/SemaCXX/nested-name-spec.cpp
@@ -178,7 +178,7 @@ bool (foo_S::value);
 
 
 namespace somens {
-  struct a { };
+  struct a { }; // expected-note{{candidate function}}
 }
 
 template <typename T>
@@ -189,7 +189,7 @@ class foo {
 // PR4452 / PR4451
 foo<somens:a> a2;  // expected-error {{unexpected ':' in nested name specifier}}
 
-somens::a a3 = a2; // expected-error {{cannot initialize 'a3' with an lvalue of type 'foo<somens::a>'}}
+somens::a a3 = a2; // expected-error {{no viable conversion}}
 
 // typedefs and using declarations.
 namespace test1 {
diff --git a/test/SemaTemplate/default-expr-arguments.cpp b/test/SemaTemplate/default-expr-arguments.cpp
index 4c2f5465dc..df3cc96ba2 100644
--- a/test/SemaTemplate/default-expr-arguments.cpp
+++ b/test/SemaTemplate/default-expr-arguments.cpp
@@ -6,9 +6,9 @@ class C { C(int a0 = 0); };
 template<>
 C<char>::C(int a0);
 
-struct S { };
+struct S { }; // expected-note 3 {{candidate function}}
 
-template<typename T> void f1(T a, T b = 10) { } // expected-error{{cannot initialize 'b' with an rvalue of type 'int'}}
+template<typename T> void f1(T a, T b = 10) { } // expected-error{{no viable conversion}}
 
 template<typename T> void f2(T a, T b = T()) { }
 
@@ -26,8 +26,8 @@ void g() {
 }
 
 template<typename T> struct F {
-  F(T t = 10); // expected-error{{cannot initialize 't' with an rvalue of type 'int'}}
-  void f(T t = 10); // expected-error{{cannot initialize 't' with an rvalue of type 'int'}}
+  F(T t = 10); // expected-error{{no viable conversion}}
+  void f(T t = 10); // expected-error{{no viable conversion}}
 };
 
 struct FD : F<int> { };
diff --git a/test/SemaTemplate/fun-template-def.cpp b/test/SemaTemplate/fun-template-def.cpp
index 867b1c643e..cc28553ebc 100644
--- a/test/SemaTemplate/fun-template-def.cpp
+++ b/test/SemaTemplate/fun-template-def.cpp
@@ -8,7 +8,7 @@
 // Fake typeid, lacking a typeinfo header.
 namespace std { class type_info {}; }
 
-struct dummy {};
+struct dummy {}; // expected-note{{candidate function}}
 
 template<typename T>
 int f0(T x) {
@@ -40,7 +40,7 @@ T f1(T t1, U u1, int i1)
   delete t1;
 
   dummy d1 = sizeof(t1); // FIXME: delayed checking okay?
-  dummy d2 = offsetof(T, foo); // expected-error {{cannot initialize 'd2'}}
+  dummy d2 = offsetof(T, foo); // expected-error {{no viable conversion}}
   dummy d3 = __alignof(u1); // FIXME: delayed checking okay?
   i1 = typeid(t1); // expected-error {{incompatible type assigning}}