[Bug c/53066] New: Wshadow should not warn for shadowing an extern function

[Bug c/53066] New: Wshadow should not warn for shadowing an extern function

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53066

             Bug #: 53066
           Summary: Wshadow should not warn for shadowing an extern
                    function
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: manu@gcc.gnu.org


As described by Linus here:
http://lkml.indiana.edu/hypermail/linux/kernel/0611.3/1020.html

This makes Wshadow useless on real code.

[Bug c/53066] Wshadow should not warn for shadowing an extern function

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53066

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch

--- Comment #1 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2012-04-21 16:41:42 UTC ---
Testing this patch:

--- gcc/c-decl.c        (revision 186353)
+++ gcc/c-decl.c        (working copy)
@@ -2570,12 +2570,19 @@ warn_if_shadowing (tree new_decl)
          }
        else if (TREE_CODE (old_decl) == PARM_DECL)
          warning (OPT_Wshadow, "declaration of %q+D shadows a parameter",
                   new_decl);
        else if (DECL_FILE_SCOPE_P (old_decl))
-         warning (OPT_Wshadow, "declaration of %q+D shadows a global "
-                  "declaration", new_decl);
+         {
+           /* Do not warn for variables shadowing a function
+              declaration.  */
+           if (TREE_CODE (old_decl) == FUNCTION_DECL)
+             break;
+           warning_at (DECL_SOURCE_LOCATION (new_decl), OPT_Wshadow, 
+                       "declaration of %qD shadows a global declaration",
+                       new_decl);
+         }
        else if (TREE_CODE (old_decl) == FUNCTION_DECL
                 && DECL_BUILT_IN (old_decl))
          {
            warning (OPT_Wshadow, "declaration of %q+D shadows "
                     "a built-in function", new_decl);

[Bug c/53066] Wshadow should not warn for shadowing an extern function

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53066

--- Comment #2 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2012-10-29 20:17:34 UTC ---
Author: manu
Date: Mon Oct 29 20:17:23 2012
New Revision: 192963

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192963
Log:
2012-10-29  Manuel López-Ibáñez  <manu@gcc.gnu.org>

    PR c/53066
c/
    * c-decl.c (warn_if_shadowing): Do not warn if a variable
    shadows a function, unless the variable is a function or a
    pointer-to-function.
gcc/
    * tree.h (FUNCTION_POINTER_TYPE_P): New.
testsuite/
    * gcc.dg/Wshadow-4.c: New.
    * gcc.dg/Wshadow-4.h: New.


Added:
    trunk/gcc/testsuite/gcc.dg/Wshadow-4.c
    trunk/gcc/testsuite/gcc.dg/Wshadow-4.h
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-decl.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree.h

[Bug c/53066] Wshadow should not warn for shadowing an extern function

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53066

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.8.0

--- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2012-10-29 20:20:15 UTC ---
FIXED in GCC 4.8