Improve our handling of user-defined conversions as part of overload

resolution. There are two sources of problems involving user-defined
conversions that this change eliminates, along with providing simpler
interfaces for checking implicit conversions:

  - It eliminates a case of infinite recursion found in Boost.

  - It eliminates the search for the constructor needed to copy a temporary
    generated by an implicit conversion from overload
    resolution. Overload resolution assumes that, if it gets a value
    of the parameter's class type (or a derived class thereof), there
    is a way to copy if... even if there isn't. We now model this
    properly.

llvm-svn: 101680

1 files changed, 27 insertions, 1 deletions

diff --git a/clang/test/SemaCXX/conversion-function.cpp b/clang/test/SemaCXX/conversion-function.cpp
index 972409ca5a3..dfc06506419 100644
--- a/clang/test/SemaCXX/conversion-function.cpp
+++ b/clang/test/SemaCXX/conversion-function.cpp
@@ -129,7 +129,7 @@ private:
 };
 
 A1 f() {
-  return "Hello"; // expected-error{{invokes deleted copy constructor}}
+  return "Hello"; // expected-error{{invokes deleted constructor}}
 }
 
 namespace source_locations {
@@ -176,3 +176,29 @@ namespace crazy_declarators {
     *operator int();  // expected-error {{must use a typedef to declare a conversion to 'int *'}}
   };
 }
+
+namespace smart_ptr {
+  class Y { 
+    class YRef { };
+
+    Y(Y&);
+
+  public:
+    Y();
+    Y(YRef);
+
+    operator YRef(); // expected-note{{candidate function}}
+  };
+
+  struct X { // expected-note{{candidate constructor (the implicit copy constructor) not}}
+    explicit X(Y);
+  };
+
+  Y make_Y();
+
+  X f() {
+    X x = make_Y(); // expected-error{{no viable conversion from 'smart_ptr::Y' to 'smart_ptr::X'}}
+    X x2(make_Y());
+    return X(Y());
+  }
+}