On Mar 29, 6:05 am, greg <g...@cosc.canterbury.ac.nzwrote:
In my quest to eliminate C compiler warnings from
Pyrex output, I've discovered some utterly bizarre
behaviour from gcc 3.3.
The following code:
void g(struct foo *x) {
}
void f(void) {
void (*h)(struct foo *);
h = g;
}
produces the following warning:
blarg.c: In function `f':
blarg.c:6: warning: assignment from incompatible pointer type
However, adding the following line at the top:
typedef struct foo Foo;
makes the warning go away. The mere *presence* of
the typedef is all that's needed -- it doesn't even
have to be used.
This looks like a bug in gcc to me -- what do people
think?
Was there no (forward) declaration nor
definition of struct foo ahead of your functions?
I get no warnings with this:
struct foo; /* forward declaration */
void g(struct foo *x) {
}
void f(void) {
void (*h)(struct foo *);
h = g;
}
Using:
Target: powerpc-apple-darwin8
Configured with: /private/var/tmp/gcc/gcc-5026.obj~19/src/configure --
disable-checking --prefix=/usr --mandir=/share/man --enable-
languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^+.-]*$/s/
$/-4.0/ --with-gxx-include-dir=/include/gcc/darwin/4.0/c++ --
build=powerpc-apple-darwin8 --host=powerpc-apple-darwin8 --
target=powerpc-apple-darwin8
Thread model: posix
gcc version 4.0.0 (Apple Computer, Inc. build 5026)
--
Hope this helps,
Steven