Reimplement constructor declarator parsing to cope with template-ids

that name constructors, the endless joys of out-of-line constructor
definitions, and various other corner cases that the previous hack
never imagined. Fixes PR5688 and tightens up semantic analysis for
constructor names.

Additionally, fixed a problem where we wouldn't properly enter the
declarator scope of a parenthesized declarator. We were entering the
scope, then leaving it when we saw the ")"; now, we re-enter the
declarator scope before parsing the parameter list.

Note that we are forced to perform some tentative parsing within a
class (call it C) to tell the difference between

  C(int); // constructor

and

  C (f)(int); // member function

which is rather unfortunate. And, although it isn't necessary for
correctness, we use the same tentative-parsing mechanism for
out-of-line constructors to improve diagnostics in icky cases like:

  C::C C::f(int); // error: C::C refers to the constructor name, but
                  // we complain nicely and recover by treating it as
                  // a type.

llvm-svn: 93322

4 files changed, 72 insertions, 7 deletions

diff --git a/clang/test/CXX/basic/basic.lookup/basic.lookup.qual/class.qual/p2.cpp b/clang/test/CXX/basic/basic.lookup/basic.lookup.qual/class.qual/p2.cpp
new file mode 100644
index 00000000000..7ecedd5a6a0
--- /dev/null
+++ b/clang/test/CXX/basic/basic.lookup/basic.lookup.qual/class.qual/p2.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+struct X0 {
+  X0 f1();
+  X0 f2();
+};
+
+template<typename T>
+struct X1 {
+  X1<T>(int);
+  (X1<T>)(float);
+  X1 f2();
+  X1 f2(int);
+  X1 f2(float);
+};
+
+// Error recovery: out-of-line constructors whose names have template arguments.
+template<typename T> X1<T>::X1<T>(int) { } // expected-error{{out-of-line constructor for 'X1' cannot have template arguments}}
+template<typename T> (X1<T>::X1<T>)(float) { } // expected-error{{out-of-line constructor for 'X1' cannot have template arguments}}
+
+// Error recovery: out-of-line constructor names intended to be types
+X0::X0 X0::f1() { return X0(); } // expected-error{{qualified reference to 'X0' is a constructor name rather than a type wherever a constructor can be declared}}
+
+struct X0::X0 X0::f2() { return X0(); }
+
+template<typename T> X1<T>::X1<T> X1<T>::f2() { } // expected-error{{qualified reference to 'X1' is a constructor name rather than a template name wherever a constructor can be declared}}
+template<typename T> X1<T>::X1<T> (X1<T>::f2)(int) { } // expected-error{{qualified reference to 'X1' is a constructor name rather than a template name wherever a constructor can be declared}}
+template<typename T> struct X1<T>::X1<T> (X1<T>::f2)(float) { }
diff --git a/clang/test/CXX/special/class.ctor/p1.cpp b/clang/test/CXX/special/class.ctor/p1.cpp
new file mode 100644
index 00000000000..9500a7d2346
--- /dev/null
+++ b/clang/test/CXX/special/class.ctor/p1.cpp
@@ -0,0 +1,42 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+struct X0 {
+  struct type { };
+
+  X0();
+  X0(int);
+  (X0)(float);
+  X0 (f0)(int);
+  X0 (f0)(type);
+  
+  X0 f1();
+  X0 f1(double);
+};
+
+X0::X0() { }
+(X0::X0)(int) { }
+
+X0 (X0::f0)(int) { return X0(); }
+
+template<typename T>
+struct X1 {
+  struct type { };
+
+  X1<T>();
+  X1<T>(int);
+  (X1<T>)(float);
+  X1(float, float);
+  (X1)(double);
+  X1<T> (f0)(int);
+  X1<T> (f0)(type);
+  X1 (f1)(int);
+  X1 (f1)(type);
+
+  template<typename U> X1(U);
+  X1 f2();
+  X1 f2(int);
+};
+
+template<typename T> X1<T>::X1() { }
+template<typename T> (X1<T>::X1)(double) { }
+template<typename T> X1<T> X1<T>::f1(int) { return 0; }
+template<typename T> X1<T> (X1<T>::f1)(type) { return 0; }
diff --git a/clang/test/SemaTemplate/injected-class-name.cpp b/clang/test/SemaTemplate/injected-class-name.cpp
index 1a65aeb3d6c..482eae14ba5 100644
--- a/clang/test/SemaTemplate/injected-class-name.cpp
+++ b/clang/test/SemaTemplate/injected-class-name.cpp
@@ -11,11 +11,7 @@ struct X<int***> {
   typedef X<int***> *ptr;
 };
 
-// FIXME: EDG rejects this in their strict-conformance mode, but I
-// don't see any wording making this ill-formed.  Actually,
-// [temp.local]p2 might make it ill-formed. Are we "in the scope of
-// the class template specialization?"
-X<float>::X<int> xi = x;
+X<float>::X<int> xi = x; // expected-error{{qualified reference to 'X' is a constructor name rather than a template name wherever a constructor can be declared}}
 
 // [temp.local]p1:
 
diff --git a/clang/test/SemaTemplate/instantiate-member-class.cpp b/clang/test/SemaTemplate/instantiate-member-class.cpp
index 8a19d74cdde..742abcc569c 100644
--- a/clang/test/SemaTemplate/instantiate-member-class.cpp
+++ b/clang/test/SemaTemplate/instantiate-member-class.cpp
@@ -14,8 +14,8 @@ public:
 X<int>::C *c1;
 X<float>::C *c2;
 
-X<int>::X *xi;
-X<float>::X *xf;
+X<int>::X *xi; // expected-error{{qualified reference to 'X' is a constructor name rather than a type wherever a constructor can be declared}}
+X<float>::X *xf; // expected-error{{qualified reference to 'X' is a constructor name rather than a type wherever a constructor can be declared}}
 
 void test_naming() {
   c1 = c2; // expected-error{{incompatible type assigning 'X<float>::C *', expected 'X<int>::C *'}}