[PATCH] diagnose specializations of deprecated templates (PR c++/84318)

[Martin Sebor <msebor@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 655 bytes --]

While testing my fix for 83871 (handling attributes on explicit
specializations) I noticed another old regression: while GCC 4.4
would diagnose declarations of explicit soecializations of all
primary templates declared deprecated, GCC 4.5 and later only
diagnose declarations of explicit soecializations of class
templates but not those of function or variable templates.

The root cause of this regression is different than 83871 so I
prefer to fix each separately.  The attached patch does that.
Because there is an opportunity to share code between the two
fixes I expect to integrate one into the other (whichever is
approved/committed last).

Martin

[-- Attachment #2: gcc-84318.diff --]
[-- Type: text/x-patch, Size: 3249 bytes --]

PR c++/84318 - attribute deprecated on function templates different than class templates

gcc/cp/ChangeLog:

	PR c++/84318
	* pt.c (check_explicit_specialization): Warn for explicit
	specializations of deprecated primary templates.

gcc/testsuite/ChangeLog:

	PR c++/84318
	* g++.dg/ext/attr-deprecated-2.C: New test.

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index b58c60f..aa5f0dd 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -3104,6 +3104,20 @@ check_explicit_specialization (tree declarator,
 	  else if (VAR_P (decl))
 	    DECL_COMDAT (decl) = false;
 
+	  if (TREE_CODE (gen_tmpl) != TYPE_DECL)
+	    {
+	      tree tmpl = gen_tmpl;
+	      if (DECL_FUNCTION_TEMPLATE_P (tmpl)
+		  || TREE_CODE (tmpl) == TEMPLATE_DECL)
+		tmpl = DECL_TEMPLATE_RESULT (tmpl);
+
+	      /* Diagnose declarations of specializations of
+		 a deprecated primary template.  */
+	      if (TREE_DEPRECATED (tmpl)
+		  || lookup_attribute ("deprecated", DECL_ATTRIBUTES (tmpl)))
+		warn_deprecated_use (tmpl, NULL_TREE);
+	    }
+
 	  /* If this is a full specialization, register it so that we can find
 	     it again.  Partial specializations will be registered in
 	     process_partial_specialization.  */
diff --git a/gcc/testsuite/g++.dg/ext/attr-deprecated-2.C b/gcc/testsuite/g++.dg/ext/attr-deprecated-2.C
new file mode 100644
index 0000000..f639a73
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-deprecated-2.C
@@ -0,0 +1,63 @@
+// PR c++/84318 - attribute deprecated on function templates different
+// than class templates
+// { dg-do compile }
+// { dg-options "-Wall" }
+
+#define DEPRECATED __attribute__ ((deprecated))
+
+template <typename T>
+struct DEPRECATED
+ClassPartial { };                       // { dg-message "declared here" }
+
+// Verify that a partial specialization is diagnosed.
+template <typename T>
+struct ClassPartial<const T> { };       // { dg-warning ".template *<class T> struct ClassPartial. is deprecated" }
+
+
+template <typename T>
+struct
+ClassPartialDeprecated { };
+
+template <typename T>
+struct DEPRECATED
+ClassPartialDeprecated<T*> { };
+
+ClassPartialDeprecated<int> cpdi;
+ClassPartialDeprecated<int*> cpdci;     // { dg-warning "is deprecated" "bug 84347" { xfail *-*-* } }
+
+
+template <typename T>
+struct DEPRECATED
+ClassExplicit { };                      // { dg-message "declared here" }
+
+template <>
+struct
+ClassExplicit<int> { };                 // { dg-warning ".template *<class T> struct ClassExplicit. is deprecated" }
+
+
+template <typename T>
+void DEPRECATED
+FuncExplicit ();                        // { dg-message "declared here" }
+
+template <>
+void
+FuncExplicit<int>();                    // { dg-warning ".void FuncExplicit\\\(\\\). is deprecated" }
+
+
+template <typename T>
+int DEPRECATED
+VarPartial;                             // { dg-message "declared here" }
+
+template <class T>
+int
+VarPartial<const T>;                    // { dg-warning ".VarPartial<T>. is deprecated" }
+
+template <typename T>
+int DEPRECATED
+VarExplicit;                            // { dg-message "declared here" }
+
+template <>
+int
+VarExplicit<int>;                       // { dg-warning ".VarExplicit<T>. is deprecated" }
+
+// { dg-prune-output "variable templates only available" }