Re: [PATCH] c-pragma: adding a data field to pragma_handler

[Pierre Vittet <piervit@pvittet.com>]

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Hello,

I am sorry, my editor (vim) was not correctly configure (I used 
http://gcc.gnu.org/ml/gcc/2011-03/msg00425.html to improve it). I guess 
it is ok now.
If I still have issue, I will post on the mailing list if there is some 
tips for vim otherway I will use Emacs (I am not very comfortable with 
it for now ;).

Pierre Vittet

On 03/06/2011 17:47, Basile Starynkevitch wrote:
> On Fri, 03 Jun 2011 17:31:25 +0200
> Pierre Vittet<piervit@pvittet.com>  wrote:
>
>    
>> Thank you for your answer!
>>
>> I send you a new patch
>> I have corrected the errors you raised.
>>
>> I have make my patch compatible with the old use of c_register_pragma
>> and c_register_pragma_with_expansion.
>>      
> I find the patch quite interesting, but I cannot approve it.
>
>   void
> +c_register_pragma_with_expansion_and_data (const char *space, const char *name,
> +				                                   pragma_handler_2arg handler,
> +                                           void * data)
>
> Perhaps there are some spaces (vs tabs) issues here.
>
> Cheers
>    


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Index: gcc/c-family/c-pragma.c
===================================================================
--- gcc/c-family/c-pragma.c	(revision 174521)
+++ gcc/c-family/c-pragma.c	(working copy)
@@ -1148,12 +1148,12 @@ handle_pragma_float_const_decimal64 (cpp_reader *A
 }
 
 /* A vector of registered pragma callbacks.  */
+/* This is never freed as we need it during the whole execution.  */
+DEF_VEC_O (internal_pragma_handler);
+DEF_VEC_ALLOC_O (internal_pragma_handler, heap);
 
-DEF_VEC_O (pragma_handler);
-DEF_VEC_ALLOC_O (pragma_handler, heap);
+static VEC(internal_pragma_handler, heap) *registered_pragmas;
 
-static VEC(pragma_handler, heap) *registered_pragmas;
-
 typedef struct
 {
   const char *space;
@@ -1216,7 +1216,7 @@ c_pp_lookup_pragma (unsigned int id, const char **
 
 static void
 c_register_pragma_1 (const char *space, const char *name,
-		     pragma_handler handler, bool allow_expansion)
+                     internal_pragma_handler ihandler, bool allow_expansion)
 {
   unsigned id;
 
@@ -1235,8 +1235,9 @@ c_register_pragma_1 (const char *space, const char
     }
   else
     {
-      VEC_safe_push (pragma_handler, heap, registered_pragmas, &handler);
-      id = VEC_length (pragma_handler, registered_pragmas);
+      VEC_safe_push (internal_pragma_handler, heap, registered_pragmas,
+                     &ihandler);
+      id = VEC_length (internal_pragma_handler, registered_pragmas);
       id += PRAGMA_FIRST_EXTERNAL - 1;
 
       /* The C++ front end allocates 6 bits in cp_token; the C front end
@@ -1248,28 +1249,90 @@ c_register_pragma_1 (const char *space, const char
 				allow_expansion, false);
 }
 
+/* Register a C pragma handler, using a space and a name.  It disallows pragma
+expansion (if you want it, use c_register_pragma_with_expansion instead).  */
 void
-c_register_pragma (const char *space, const char *name, pragma_handler handler)
+c_register_pragma (const char *space, const char *name,
+                   pragma_handler_1arg handler)
 {
-  c_register_pragma_1 (space, name, handler, false);
+  internal_pragma_handler ihandler;
+
+  ihandler.handler.handler_1arg = handler;
+  ihandler.extra_data = false;
+  ihandler.data = NULL;
+  c_register_pragma_1 (space, name, ihandler, false);
 }
 
+/* Register a C pragma handler, using a space and a name, it also carries an
+extra data field which can be used by the handler.  It disallows pragma
+expansion (if you want it, use c_register_pragma_with_expansion instead).  */
 void
+c_register_pragma_with_data (const char *space, const char *name,
+                             pragma_handler_2arg handler, void * data)
+{
+  internal_pragma_handler ihandler;
+
+  ihandler.handler.handler_2arg = handler;
+  ihandler.extra_data = true;
+  ihandler.data = data;
+  c_register_pragma_1 (space, name, ihandler, false);
+}
+
+/* Register a C pragma handler, using a space and a name.  It allows pragma
+expansion as in the following exemple:
+  #define NUMBER 10
+  #pragma count (NUMBER)
+Name expansion is still disallowed.  */
+void
 c_register_pragma_with_expansion (const char *space, const char *name,
-				  pragma_handler handler)
+				  pragma_handler_1arg handler)
 {
-  c_register_pragma_1 (space, name, handler, true);
+  internal_pragma_handler ihandler;
+
+  ihandler.handler.handler_1arg = handler;
+  ihandler.extra_data = false;
+  ihandler.data = NULL;
+  c_register_pragma_1 (space, name, ihandler, true);
 }
 
+/* Register a C pragma handler, using a space and a name, it also carries an
+extra data field which can be used by the handler.  It allows pragma expansion
+as in the following exemple:
+  #define NUMBER 10
+  #pragma count (NUMBER)
+Name expansion is still disallowed.  */
 void
+c_register_pragma_with_expansion_and_data (const char *space, const char *name,
+                                           pragma_handler_2arg handler,
+                                           void * data)
+{
+  internal_pragma_handler ihandler;
+
+  ihandler.handler.handler_2arg = handler;
+  ihandler.extra_data = true;
+  ihandler.data = data;
+  c_register_pragma_1 (space, name, ihandler, true);
+}
+
+void
 c_invoke_pragma_handler (unsigned int id)
 {
-  pragma_handler handler;
+  internal_pragma_handler * ihandler;
+  pragma_handler_1arg handler_1arg;
+  pragma_handler_2arg handler_2arg;
 
   id -= PRAGMA_FIRST_EXTERNAL;
-  handler = *VEC_index (pragma_handler, registered_pragmas, id);
-
-  handler (parse_in);
+  ihandler = VEC_index (internal_pragma_handler, registered_pragmas, id);
+  if (ihandler->extra_data)
+    {
+      handler_2arg = ihandler->handler.handler_2arg;
+      handler_2arg (parse_in, ihandler->data);
+    }
+  else
+    {
+      handler_1arg = ihandler->handler.handler_1arg;
+      handler_1arg (parse_in);
+    }
 }
 
 /* Set up front-end pragmas.  */
@@ -1308,7 +1371,8 @@ init_pragma (void)
   c_register_pragma ("STDC", "FLOAT_CONST_DECIMAL64",
 		     handle_pragma_float_const_decimal64);
 
-  c_register_pragma_with_expansion (0, "redefine_extname", handle_pragma_redefine_extname);
+  c_register_pragma_with_expansion (0, "redefine_extname",
+                                    handle_pragma_redefine_extname);
   c_register_pragma (0, "extern_prefix", handle_pragma_extern_prefix);
 
   c_register_pragma_with_expansion (0, "message", handle_pragma_message);
Index: gcc/c-family/c-pragma.h
===================================================================
--- gcc/c-family/c-pragma.h	(revision 174521)
+++ gcc/c-family/c-pragma.h	(working copy)
@@ -84,10 +84,39 @@ extern bool pop_visibility (int);
 extern void init_pragma (void);
 
 /* Front-end wrappers for pragma registration.  */
-typedef void (*pragma_handler)(struct cpp_reader *);
-extern void c_register_pragma (const char *, const char *, pragma_handler);
-extern void c_register_pragma_with_expansion (const char *, const char *,
-					      pragma_handler);
+typedef void (*pragma_handler_1arg)(struct cpp_reader *);
+/* A second pragma handler, which adds a void * argument allowing to pass extra
+data to the handler.  */
+typedef void (*pragma_handler_2arg)(struct cpp_reader *, void *);
+
+/* This union permits abstact the different handlers.  */
+union gen_pragma_handler {
+  pragma_handler_1arg handler_1arg;
+  pragma_handler_2arg handler_2arg;
+};
+/* Internally use to keep the data of the handler.  The field extra_data permit
+to know if handler is a pragma_handler_1arg (extra_data is false), or a
+pragma_handler_2arg (extra_data is true).  */
+struct internal_pragma_handler_d {
+  union gen_pragma_handler handler;
+  bool extra_data;
+  void * data;
+};
+typedef struct internal_pragma_handler_d internal_pragma_handler;
+
+extern void c_register_pragma (const char * space, const char * name,
+                               pragma_handler_1arg handler);
+extern void c_register_pragma_with_data (const char * space, const char * name,
+                                         pragma_handler_2arg handler,
+                                         void * data);
+
+extern void c_register_pragma_with_expansion (const char * space,
+                                              const char * name,
+                                              pragma_handler_1arg handler);
+extern void c_register_pragma_with_expansion_and_data (const char * space,
+                                                       const char * name,
+                                                   pragma_handler_2arg handler,
+                                                       void * data);
 extern void c_invoke_pragma_handler (unsigned int);
 
 extern void maybe_apply_pragma_weak (tree);