[clang] Correct source locations for instantiations of function templates.

This change corrects some cases where the source location for an instantiated specialization of a function template or a member function of a class template was assigned the location of a non-defining declaration rather than the location of the definition the specialization was instantiated from. Fixes #26057 Reviewed By: cor3ntin Differential Revision: https://reviews.llvm.org/D64087

Author: tahonermann

clang/docs/ReleaseNotes.rst

@@ -291,6 +291,12 @@ Bug Fixes to C++ Support
  pointers on win32.
  (`#62594 <https://github.com/llvm/llvm-project/issues/62594>`_)
 
+- Fixed some cases where the source location for an instantiated specialization
+ of a function template or a member function of a class template was assigned
+ the location of a non-defining declaration rather than the location of the
+ definition the specialization was instantiated from.
+ (`#26057 <https://github.com/llvm/llvm-project/issues/26057>`_`)
+
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 - Fixed an import failure of recursive friend class template.

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -4990,8 +4990,10 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
  // unimported module.
  Function->setVisibleDespiteOwningModule();
 
- // Copy the inner loc start from the pattern.
+ // Copy the source locations from the pattern.
+ Function->setLocation(PatternDecl->getLocation());
  Function->setInnerLocStart(PatternDecl->getInnerLocStart());
+ Function->setRangeEnd(PatternDecl->getEndLoc());
 
  EnterExpressionEvaluationContext EvalContext(
  *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);

clang/test/CXX/class/class.compare/class.compare.default/p1.cpp

@@ -209,10 +209,10 @@ bool operator==(e *, int *) = default; // expected-error{{must have at least one
 
 namespace p2085_2 {
 template <class T> struct S6 {
- // expected-error@+2{{found 'const int &'}}
- // expected-error@+1{{found 'const float &'}}
  bool operator==(T const &) const;
 };
+// expected-error@+2{{found 'const int &'}}
+// expected-error@+1{{found 'const float &'}}
 template <class T> bool S6<T>::operator==(T const &) const = default;
 
 template struct S6<int>; // expected-note{{S6<int>::operator==' requested}}

clang/test/SemaCXX/cxx2b-consteval-propagate.cpp

@@ -102,14 +102,14 @@ constexpr int f(T t) {
 
 namespace forward_declare_consteval{
 template <typename T>
-constexpr int f(T t); // expected-note {{'f<int>' defined here}}
+constexpr int f(T t);
 
 auto a = &f<char>;
 auto b = &f<int>; // expected-error {{immediate function 'f<int>' used before it is defined}} \
  // expected-note {{in instantiation of function template specialization}}
 
 template <typename T>
-constexpr int f(T t) {
+constexpr int f(T t) { // expected-note {{'f<int>' defined here}}
  return id(t); // expected-note {{'f<int>' is an immediate function because its body contains a call to a consteval function 'id' and that call is not a constant expression}}
 }
 }

clang/test/SemaCXX/member-init.cpp

@@ -164,11 +164,11 @@ struct A {
 
 namespace explicit_instantiation {
 template<typename T> struct X {
- X(); // expected-note {{in instantiation of default member initializer 'explicit_instantiation::X<float>::n' requested here}}
+ X();
  int n = T::error; // expected-error {{type 'float' cannot be used prior to '::' because it has no members}}
 };
 template struct X<int>; // ok
-template<typename T> X<T>::X() {}
+template<typename T> X<T>::X() {} // expected-note {{in instantiation of default member initializer 'explicit_instantiation::X<float>::n' requested here}}
 template struct X<float>; // expected-note {{in instantiation of member function 'explicit_instantiation::X<float>::X' requested here}}
 }
 
@@ -197,3 +197,15 @@ void foo(T v) {
 }
 template void foo(int);
 }
+
+namespace GH26057 {
+template<typename T>
+struct S {
+ S();
+ int dm = T::error; // expected-error {{type 'int' cannot be used prior to '::' because it has no members}}
+};
+template<typename T>
+S<T>::S() = default; // expected-note {{in instantiation of default member initializer 'GH26057::S<int>::dm' requested here}} \
+ // expected-note {{in evaluation of exception specification for 'GH26057::S<int>::S' needed here}}
+template struct S<int>; // expected-note {{in instantiation of member function 'GH26057::S<int>::S' requested here}}
+}

clang/test/SemaTemplate/virtual-member-functions.cpp

@@ -7,10 +7,10 @@
 
 namespace PR5557 {
 template <class T> struct A {
- A(); // expected-note{{instantiation}}
+ A();
  virtual int a(T x);
 };
-template<class T> A<T>::A() {}
+template<class T> A<T>::A() {} // expected-note{{instantiation}}
 
 template<class T> int A<T>::a(T x) { 
  return *x; // expected-error{{requires pointer operand}}
@@ -33,10 +33,10 @@ void X<int>::f() { }
 namespace PR5557_dtor {
 template <class T> struct A {
  A(); // Don't have an implicit constructor.
- ~A(); // expected-note{{instantiation}}
+ ~A();
  virtual int a(T x);
 };
-template<class T> A<T>::~A() {}
+template<class T> A<T>::~A() {} // expected-note{{instantiation}}
 
 template<class T> int A<T>::a(T x) { 
  return *x; // expected-error{{requires pointer operand}}