Implement template instantiation for exception specifications. Also,

print exception specifications on function types and
declarations. Fixes <rdar://problem/7450999>.

There is some poor source-location information here, because we don't
track locations of the types in exception specifications. Filed PR5719.

Failures during template instantiation of the signature of a function
or function template have wrong point-of-instantiation location
information. I'll tackle that with a separate commit.

llvm-svn: 90863

clang/lib/AST/DeclPrinter.cpp

@@ -361,6 +361,24 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
     }
 
     Proto += ")";
+    
+    if (FT && FT->hasExceptionSpec()) {
+      Proto += " throw(";
+      if (FT->hasAnyExceptionSpec())
+        Proto += "...";
+      else 
+        for (unsigned I = 0, N = FT->getNumExceptions(); I != N; ++I) {
+          if (I)
+            Proto += ", ";
+          
+          
+          std::string ExceptionType;
+          FT->getExceptionType(I).getAsStringInternal(ExceptionType, SubPolicy);
+          Proto += ExceptionType;
+        }
+      Proto += ")";
+    }
+
     if (D->hasAttr<NoReturnAttr>())
       Proto += " __attribute((noreturn))";
     if (CXXConstructorDecl *CDecl = dyn_cast<CXXConstructorDecl>(D)) {

clang/lib/AST/TypePrinter.cpp

@@ -285,6 +285,23 @@ void TypePrinter::PrintFunctionProto(const FunctionProtoType *T,
   }
   
   S += ")";
+
+  if (T->hasExceptionSpec()) {
+    S += " throw(";
+    if (T->hasAnyExceptionSpec())
+      S += "...";
+    else 
+      for (unsigned I = 0, N = T->getNumExceptions(); I != N; ++I) {
+        if (I)
+          S += ", ";
+
+        std::string ExceptionType;
+        Print(T->getExceptionType(I), ExceptionType);
+        S += ExceptionType;
+      }
+    S += ")";
+  }
+
   if (T->getNoReturnAttr())
     S += " __attribute__((noreturn))";
   Print(T->getResultType(), S);

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -1390,6 +1390,43 @@ TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
     }
   }
 
+  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
+  assert(Proto && "Function template without prototype?");
+
+  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
+      Proto->getNoReturnAttr()) {
+    // The function has an exception specification or a "noreturn"
+    // attribute. Substitute into each of the exception types.
+    llvm::SmallVector<QualType, 4> Exceptions;
+    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
+      // FIXME: Poor location information!
+      QualType T
+        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
+                            New->getLocation(), New->getDeclName());
+      if (T.isNull() || 
+          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
+        continue;
+
+      Exceptions.push_back(T);
+    }
+
+    // Rebuild the function type 
+
+    const FunctionProtoType *NewProto
+      = New->getType()->getAs<FunctionProtoType>();
+    assert(NewProto && "Template instantiation without function prototype?");
+    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
+                                                 NewProto->arg_type_begin(),
+                                                 NewProto->getNumArgs(),
+                                                 NewProto->isVariadic(),
+                                                 NewProto->getTypeQuals(),
+                                                 Proto->hasExceptionSpec(),
+                                                 Proto->hasAnyExceptionSpec(),
+                                                 Exceptions.size(),
+                                                 Exceptions.data(),
+                                                 Proto->getNoReturnAttr()));
+  }
+
   return false;
 }
 

clang/test/SemaTemplate/instantiate-exception-spec.cpp

@@ -0,0 +1,11 @@
+// RUN: clang-cc -fsyntax-only -verify %s
+
+// FIXME: the "note" should be down at the call site!
+template<typename T> void f1(T*) throw(T); // expected-error{{incomplete type 'struct Incomplete' is not allowed in exception specification}} \
+                         // expected-note{{instantiation of}}
+struct Incomplete; // expected-note{{forward}}
+
+void test_f1(Incomplete *incomplete_p, int *int_p) {
+  f1(int_p);
+  f1(incomplete_p); 
+}