[Bug c/47772] New: warnings from -Wmissing-field-initializers contradict documentation

[Bug c/47772] New: warnings from -Wmissing-field-initializers contradict documentation

[darren at kulp dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47772

           Summary: warnings from -Wmissing-field-initializers contradict
                    documentation
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: darren@kulp.ch


Created attachment 23367
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23367
testcase re: -Wmissing-field-initializers and designated initializers

According to gcc(1):

-Wmissing-field-initializers
           Warn if a structure's initializer has some fields missing. ... This
option does not warn about designated initializers ....

This I find normally to be true. Attached is a test case that produces the
following warning on GCC 4.2.1, 4.4.4., and 4.5.2:

$ gcc -save-temps -Wmissing-field-initializers  -c test3.c
test3.c:14: warning: missing initializer
test3.c:14: warning: (near initialization for ‘(anonymous)[0].b’)

If the `b' field is initialized either before or after the `a' field, the
warning disappears, but this should not be necessary, according to the
documentation.

[Bug c/47772] warnings from -Wmissing-field-initializers contradict documentation

[darren at kulp dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47772

--- Comment #1 from Darren Kulp <darren at kulp dot ch> 2011-02-16 20:58:17 UTC ---
Here is the output of `gcc -v' on the one system to which I have direct access:

Using built-in specs.
Target: i686-apple-darwin10
Configured with: /var/tmp/gcc/gcc-5646~6/src/configure --disable-checking
--enable-werror --prefix=/usr --mandir=/share/man
--enable-languages=c,objc,c++,obj-c++
--program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib
--build=i686-apple-darwin10 --with-gxx-include-dir=/include/c++/4.2.1
--program-prefix=i686-apple-darwin10- --host=x86_64-apple-darwin10
--target=i686-apple-darwin10
Thread model: posix
gcc version 4.2.1 (Apple Inc. build 5646)

[Bug c/47772] warnings from -Wmissing-field-initializers contradict documentation

[webmaster@sky-siteweb.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47772

Jonathan 'Sky' Squirawski <webmaster@sky-siteweb.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |webmaster@sky-siteweb.com

--- Comment #2 from Jonathan 'Sky' Squirawski <webmaster@sky-siteweb.com> 2011-02-21 16:55:39 UTC ---
I've the same problem with gcc 4.5.2.

Here another test case:

/*==================================*/
typedef struct bar_t {
    int a;
    int b;
} bar_t;

typedef struct foo_ok_t {
    int   bar;
    bar_t foo;
} foo_ok_t;

typedef struct foo_nok_t {
    bar_t bar;
    bar_t foo;
} foo_nok_t;

int main(void) {
    foo_ok_t foo_ok;
    foo_nok_t foo_nok;

    foo_ok = (foo_ok_t){
        .bar = 32,
    };

    foo_nok = (foo_nok_t){
        .bar = (bar_t){ .a = 32, .b = 42 },
    };

    return 0;
}
/*==================================*/


The first assignment doesn't trigger any warning, but the second one gives:
test.c:29:5: warning: missing initializer
test.c:29:5: warning: (near initialization for ‘(anonymous).foo’)

[Bug c/47772] warnings from -Wmissing-field-initializers contradict documentation

[vadmium+gc at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47772

Marty <vadmium+gc at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vadmium+gc at gmail dot com

--- Comment #3 from Marty <vadmium+gc at gmail dot com> 2012-04-18 12:30:44 UTC ---
Possibly related: Bug 36446, Bug 47772

[Bug c/47772] warnings from -Wmissing-field-initializers contradict documentation

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47772

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |manu at gcc dot gnu.org
         Resolution|                            |DUPLICATE

--- Comment #4 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2012-04-18 13:23:42 UTC ---
Duplicated. See my comments in PR36446.

*** This bug has been marked as a duplicate of bug 36446 ***