PATCH: new flag to say when things are instantiated

[Brendan Kehoe <brendan at zen dot org>]

I've found this feature to be particularly helpful in some situations.  By
making it possible for users to know precisely when the compiler is doing
something for them, it can both help new C++ developers grasp the language
better, and also help you know when seemingly obscure bugs happen due to a
random instantiation you didn't know about.

Ok?

B

2000-11-08  Brendan Kehoe  <brendan@zen.org>

	* decl2.c (warn_instantiations): New variable.
	(lang_decode_option): Set it for -Winstantiations.
	* pt.c (instantiate_decl): If WARN_INSTANTIATIONS, tell the user
	when an instantiatiation has taken place.
	(instantiate_class_template): Likewise for classes.
	* lang-options.h: Add -Winstantiations/-Wno-instantiations.

Index: cp-tree.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/cp-tree.h,v
retrieving revision 1.539
diff -u -p -r1.539 cp-tree.h
--- cp-tree.h	2000/10/31 08:43:16	1.539
+++ cp-tree.h	2000/11/08 16:58:02
@@ -3202,6 +3205,10 @@ extern int warn_multichar;
     declared in a templatized class. This behavior is warned about with
     flag_guiding_decls in do_friend. */
  extern int warn_nontemplate_friend;
+
+/* Nonzero means warn when each variable, function, or type is 
instantiated.  */
+
+extern int warn_instantiations;

  /* in c-common.c */
  extern void declare_function_name               PARAMS ((void));
Index: lang-options.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/lang-options.h,v
retrieving revision 1.36
diff -u -p -r1.36 lang-options.h
--- lang-options.h	2000/06/06 20:11:40	1.36
+++ lang-options.h	2000/11/08 16:58:19
@@ -135,6 +137,8 @@ DEFINE_LANG_NAME ("C++")
    { "-Wold-style-cast", "Warn if a C style cast is used in a program" },
    { "-Wno-old-style-cast", "" },
    { "-Wnon-template-friend", "" },
+  { "-Winstantiations", "Warn on the instantiation of each variable, 
function, and type" },
+  { "-Wno-instantiations", "" },
    { "-Wno-non-template-friend", "Don't warn when non-templatized 
friend functions are declared within a template" },
    { "-Wdeprecated", "" },
    { "-Wno-deprecated", "Don't announce deprecation of compiler 
features" },
Index: pt.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/pt.c,v
retrieving revision 1.475
diff -u -p -r1.475 pt.c
--- pt.c	2000/11/07 22:49:57	1.475
+++ pt.c	2000/11/08 16:59:00
@@ -5119,6 +5119,9 @@ instantiate_class_template (type)
    TYPE_BEING_DEFINED (type) = 0;
    repo_template_used (type);

+  if (warn_instantiations)
+    cp_warning ("instantiated template class `%#T'", type);
+
    /* Now that the class is complete, instantiate default arguments for
       any member functions.  We don't do this earlier because the
       default arguments may reference members of the class.  */
@@ -9675,6 +9678,9 @@ instantiate_decl (d, defer_ok)
  	  DECL_NOT_REALLY_EXTERN (d) = 1;
  	}
        cp_finish_decl (d, DECL_INITIAL (d), NULL_TREE, 0);
+
+      if (warn_instantiations)
+ 
cp_warning ("instantiated variable `%#D'", d);
      }
    else if (TREE_CODE (d) == FUNCTION_DECL)
      {
@@ -9707,6 +9713,9 @@ instantiate_decl (d, defer_ok)

        /* Finish the function.  */
        expand_body (finish_function (0));
+
+      if (warn_instantiations)
+ 
cp_warning ("instantiated function `%#D'", d);
      }

    /* We're not deferring instantiation any more.  */
Index: decl2.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/decl2.c,v
retrieving revision 1.409
diff -u -p -u -2 -p -r1.409 decl2.c
--- decl2.c	2000/11/08 14:03:29	1.409
+++ decl2.c	2000/11/08 17:06:13
@@ -346,4 +357,8 @@ int warn_multichar = 1;
  int warn_nontemplate_friend = 1;

+/* Nonzero means warn when each variable, function, or type is 
instantiated.  */
+
+int warn_instantiations = 0;
+
  /* Nonzero means complain about deprecated features.  */

@@ -774,4 +795,6 @@ lang_decode_option (argc, argv)
        else if (!strcmp (p, "non-template-friend"))
  	warn_nontemplate_friend = setting;
+      else if (!strcmp (p, "instantiations"))
+ 
warn_instantiations = setting;
        else if (!strcmp (p, "deprecated"))
          warn_deprecated = setting;


-- 
Brendan Kehoe

CTO of Nobie.com (http://www.nobie.com/)
        -- Finally true Net marketing in .ie