[Bug c/59717] New: better warning when using functions when including appropriate header files

[Bug c/59717] New: better warning when using functions when including appropriate header files

[metherid at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59717

            Bug ID: 59717
           Summary: better warning when using functions when including
                    appropriate header files
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: metherid at gmail dot com

Clang produces a better warning suggesting the appropriate header file compared
to GCC.  Test program included

$gcc testwarning.c 

testwarning.c: In function ‘main’:
testwarning.c:4:2: warning: incompatible implicit declaration of built-in
function ‘strcpy’ [enabled by default]
  strcpy(teststr, "foo");
  ^

rahul@mether ~/work> clang test

testfor  testfor.c  testwarning.c  
rahul@mether ~/work> clang testwarning.c 
testwarning.c:4:2: warning: implicitly declaring library function 'strcpy' with
      type 'char *(char *, const char *)'
        strcpy(teststr, "foo");
        ^
testwarning.c:4:2: note: please include the header <string.h> or explicitly
      provide a declaration for 'strcpy'

---

cat testwarning.c 
int main (void) {

    char *teststr;
    strcpy(teststr, "foo");
---
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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/59712] unordered_map : clang fails with "member access into incomplete type"
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idY712

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|major                       |normal

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This is not Severity=major, libstdc++ is designed for use with GCC not Clang.

[Bug c/59717] better warning when using functions when including appropriate header files

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59717

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
           Severity|normal                      |enhancement

[Bug c/59717] better warning when using functions without including appropriate header files

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59717

Steven Bosscher <steven at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-01-25
                 CC|                            |steven at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Steven Bosscher <steven at gcc dot gnu.org> ---
Can be implemented by adding header names in the builtins.def files.

[Bug c/59717] better warning when using functions without including appropriate header files

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59717

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |mpolacek at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |5.0

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
On it.

[Bug c/59717] better warning when using functions without including appropriate header files

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59717

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.

[Bug c/59717] better warning when using functions without including appropriate header files

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59717

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Author: mpolacek
Date: Tue Oct  7 17:49:46 2014
New Revision: 215979

URL: https://gcc.gnu.org/viewcvs?rev=215979&root=gcc&view=rev
Log:
    PR c/59717
    * c-decl.c (header_for_builtin_fn): New function.
    (implicitly_declare): Suggest which header to include.

    * gcc.dg/pr59717.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr59717.c
Modified:
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-decl.c
    trunk/gcc/testsuite/ChangeLog