| Message ID | CAE+uiWYwGEeAHs7LiTaxyQZgkTdJ7Y1Pvzaf8pVi0WxbBBJv7A@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On 11 April 2016 at 20:09, Prasad Ghangal <prasad.ghangal@gmail.com> wrote: > > Hi! > > This is proposed patch for > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48116 (-Wreturn-type does > not work as advertised) > > Currently gcc doesn't give any warning with -Wreturn-type or -Wall > option for test cases like : > > void x (void) { } > void y(void) { return x(); } > > > applying this patch gives: > > $gcc foo.c -S -Wreturn-type > foo.c: In function ‘y’: > foo.c:2:23: warning: ISO C forbids ‘return’ with expression, in > function returning void [-Wreturn-type] > void y(void) { return x(); } > ^~~ > foo.c:2:6: note: declared here > void y(void) { return x(); } > ^ > > $gcc foo.c -S -Wall > foo.c: In function ‘y’: > foo.c:2:23: warning: ISO C forbids ‘return’ with expression, in > function returning void [-Wreturn-type] > void y(void) { return x(); } > ^~~ > foo.c:2:6: note: declared here > void y(void) { return x(); } > ^ > > $gcc foo.c -S -pedantic > foo.c: In function ‘y’: > foo.c:2:23: warning: ISO C forbids ‘return’ with expression, in > function returning void [-Wpedantic] > void y(void) { return x(); } > ^~~ > foo.c:2:6: note: declared here > void y(void) { return x(); } > ^ > > > I have fully bootstrapped and tested on x86_64-pc-linux. > > > > Thanks, > Prasad Ghangal *PING* https://gcc.gnu.org/ml/gcc-patches/2016-04/msg00474.html Is this patch OK for gcc 7? Thanks, Prasad Ghangal
On Mon, 11 Apr 2016, Prasad Ghangal wrote: > Hi! > > This is proposed patch for > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48116 (-Wreturn-type does > not work as advertised) I think that this is actually a documentation bug and should be fixed by changing the documentation, not by changing the code. That is, the patch <https://gcc.gnu.org/ml/gcc-patches/2007-02/msg01102.html> that added the assertion about return with a value from functions returning void was mistaken: if the expression is non-void, the diagnostic is mandatory, and if it's a void expression, this is a legitimate, long-standing extension to ISO C, taken from ISO C++, and should be documented as such and not warned for except with -pedantic. So there should be two documentation changes: (a) correct the description of -Wreturn-type and (b) explicitly document return of void expressions from functions returning void as a GNU C extension taken from ISO C++.
Index: gcc/c/ChangeLog =================================================================== diff --git a/trunk/gcc/c/ChangeLog b/trunk/gcc/c/ChangeLog --- a/trunk/gcc/c/ChangeLog (revision 234872) +++ b/trunk/gcc/c/ChangeLog (working copy) @@ -1,3 +1,8 @@ +2016-04-11 Prasad Ghangal <prasad.ghangal@gmail.com> + + PR c/48116 + * c-typeck.c (c_finish_return): Check -Wreturn-type option + 2016-04-04 Marek Polacek <polacek@redhat.com> PR c/70307 Index: gcc/c/c-typeck.c =================================================================== diff --git a/trunk/gcc/c/c-typeck.c b/trunk/gcc/c/c-typeck.c --- a/trunk/gcc/c/c-typeck.c (revision 234872) +++ b/trunk/gcc/c/c-typeck.c (working copy) @@ -9680,6 +9680,10 @@ warned_here = pedwarn (xloc, 0, "%<return%> with a value, in function returning void"); + else if (warn_return_type) + warned_here = warning_at + (xloc, OPT_Wreturn_type, "ISO C forbids " + "%<return%> with expression, in function returning void"); else warned_here = pedwarn (xloc, OPT_Wpedantic, "ISO C forbids " Index: gcc/testsuite/ChangeLog =================================================================== diff --git a/trunk/gcc/testsuite/ChangeLog b/trunk/gcc/testsuite/ChangeLog --- a/trunk/gcc/testsuite/ChangeLog (revision 234872) +++ b/trunk/gcc/testsuite/ChangeLog (working copy) @@ -1,3 +1,8 @@ +2016-04-11 Prasad Ghangal <prasad.ghangal@gmail.com> + + PR c/48116 + * gcc.dg/pr48116.c: New test + 2016-04-10 Paolo Carlini <paolo.carlini@oracle.com> PR c++/69066 Index: gcc/testsuite/gcc.dg/pr48116.c =================================================================== diff --git a/trunk/gcc/testsuite/gcc.dg/pr48116.c b/trunk/gcc/testsuite/gcc.dg/pr48116.c new file mode 10644 --- /dev/null (revision 0) +++ b/trunk/gcc/testsuite/gcc.dg/pr48116.c (working copy) @@ -0,0 +1,6 @@ +/* PR c/48116 */ +/* { dg-do compile } */ +/* { dg-options "-Wreturn-type" } */ + +static void f() {} +static void g() { return f(); } /* { dg-warning "forbids 'return'" "missing return" } */ Index: libatomic/ChangeLog =================================================================== diff --git a/trunk/libatomic/ChangeLog b/trunk/libatomic/ChangeLog --- a/trunk/libatomic/ChangeLog (revision 234872) +++ b/trunk/libatomic/ChangeLog (working copy) @@ -1,3 +1,8 @@ +2016-04-11 Prasad Ghangal <prasad.ghangal@gmail.com> + + PR c/48116 + * flag.c (atomic_flag_clear_explicit): Remove return + 2016-01-06 Szabolcs Nagy <szabolcs.nagy@arm.com> PR other/67627 Index: libatomic/flag.c =================================================================== diff --git a/trunk/libatomic/flag.c b/trunk/libatomic/flag.c --- a/trunk/libatomic/flag.c (revision 234872) +++ b/trunk/libatomic/flag.c (working copy) @@ -60,5 +60,5 @@ (atomic_flag_clear_explicit) (volatile atomic_flag *object, memory_order order) { - return atomic_flag_clear_explicit (object, order); + atomic_flag_clear_explicit (object, order); } Index: libgomp/ChangeLog =================================================================== diff --git a/trunk/libgomp/ChangeLog b/trunk/libgomp/ChangeLog --- a/trunk/libgomp/ChangeLog (revision 234872) +++ b/trunk/libgomp/ChangeLog (working copy) @@ -1,3 +1,12 @@ +2016-04-11 Prasad Ghangal <prasad.ghangal@gmail.com> + + PR c/48116 + * fortran.c (omp_set_default_device_): Remove return + * fortran.c (omp_set_default_device_8_): Likewise + * target.c (GOMP_target): Split return and call on separate lines + * target.c (GOMP_target_data): Likewise + * target.c (GOMP_taget_data_ext): Likewise + 2016-04-08 Cesar Philippidis <cesar@codesourcery.com> PR lto/70289 Index: libgomp/fortran.c =================================================================== diff --git a/trunk/libgomp/fortran.c b/trunk/libgomp/fortran.c --- a/trunk/libgomp/fortran.c (revision 234872) +++ b/trunk/libgomp/fortran.c (working copy) @@ -526,13 +526,13 @@ void omp_set_default_device_ (const int32_t *device_num) { - return omp_set_default_device (*device_num); + omp_set_default_device (*device_num); } void omp_set_default_device_8_ (const int64_t *device_num) { - return omp_set_default_device (TO_INT (*device_num)); + omp_set_default_device (TO_INT (*device_num)); } int32_t Index: libgomp/target.c =================================================================== diff --git a/trunk/libgomp/target.c b/trunk/libgomp/target.c --- a/trunk/libgomp/target.c (revision 234872) +++ b/trunk/libgomp/target.c (working copy) @@ -1465,7 +1465,10 @@ /* All shared memory devices should use the GOMP_target_ext function. */ || devicep->capabilities & GOMP_OFFLOAD_CAP_SHARED_MEM || !(fn_addr = gomp_get_target_fn_addr (devicep, fn))) - return gomp_target_fallback (fn, hostaddrs); + { + gomp_target_fallback (fn, hostaddrs); + return; + } struct target_mem_desc *tgt_vars = gomp_map_vars (devicep, mapnum, hostaddrs, NULL, sizes, kinds, false, @@ -1616,7 +1619,10 @@ if (devicep == NULL || !(devicep->capabilities & GOMP_OFFLOAD_CAP_OPENMP_400) || (devicep->capabilities & GOMP_OFFLOAD_CAP_SHARED_MEM)) - return gomp_target_data_fallback (); + { + gomp_target_data_fallback (); + return; + } struct target_mem_desc *tgt = gomp_map_vars (devicep, mapnum, hostaddrs, NULL, sizes, kinds, false, @@ -1635,7 +1641,10 @@ if (devicep == NULL || !(devicep->capabilities & GOMP_OFFLOAD_CAP_OPENMP_400) || devicep->capabilities & GOMP_OFFLOAD_CAP_SHARED_MEM) - return gomp_target_data_fallback (); + { + gomp_target_data_fallback (); + return; + } struct target_mem_desc *tgt = gomp_map_vars (devicep, mapnum, hostaddrs, NULL, sizes, kinds, true,
Hi! This is proposed patch for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48116 (-Wreturn-type does not work as advertised) Currently gcc doesn't give any warning with -Wreturn-type or -Wall option for test cases like : void x (void) { } void y(void) { return x(); } applying this patch gives: $gcc foo.c -S -Wreturn-type foo.c: In function ‘y’: foo.c:2:23: warning: ISO C forbids ‘return’ with expression, in function returning void [-Wreturn-type] void y(void) { return x(); } ^~~ foo.c:2:6: note: declared here void y(void) { return x(); } ^ $gcc foo.c -S -Wall foo.c: In function ‘y’: foo.c:2:23: warning: ISO C forbids ‘return’ with expression, in function returning void [-Wreturn-type] void y(void) { return x(); } ^~~ foo.c:2:6: note: declared here void y(void) { return x(); } ^ $gcc foo.c -S -pedantic foo.c: In function ‘y’: foo.c:2:23: warning: ISO C forbids ‘return’ with expression, in function returning void [-Wpedantic] void y(void) { return x(); } ^~~ foo.c:2:6: note: declared here void y(void) { return x(); } ^ I have fully bootstrapped and tested on x86_64-pc-linux. Thanks, Prasad Ghangal