Ping.
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64918#c6 is not addressed in
this patch, it's something to be looked at before closing the PR.)
On Fri, Apr 24, 2015 at 12:36:25AM +0200, Marek Polacek wrote:
> As discussed in the PR, the "initialized field with side-effects overwritten"
> warning is sometimes not so useful, so it probably makes sense to provide an
> option so that users are able to specifically enable/disable it. Since the
> warning is enabled by default at present, it is enabled by default even with
> this patch, unlike -Woverride-init, which is in -Wextra.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2015-04-24 Marek Polacek <pola...@redhat.com>
>
> PR c/64918
> * c.opt (Woverride-init-side-effects): New option.
>
> * c-typeck.c (add_pending_init): Use OPT_Woverride_init_side_effects.
> (output_init_element): Likewise.
>
> * doc/invoke.texi: Document -Woverride-init-side-effects.
>
> * gcc.dg/Woverride-init-side-effects-1.c: New test.
> * gcc.dg/Woverride-init-side-effects-2.c: New test.
>
> diff --git gcc/c-family/c.opt gcc/c-family/c.opt
> index 983f4a8..50dc8ec 100644
> --- gcc/c-family/c.opt
> +++ gcc/c-family/c.opt
> @@ -709,6 +709,10 @@ Woverride-init
> C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
> Warn about overriding initializers without side effects
>
> +Woverride-init-side-effects
> +C ObjC Var(warn_override_init_side_effects) Init(1) Warning
> +Warn about overriding initializers with side effects
> +
> Wpacked-bitfield-compat
> C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
> Warn about packed bit-fields whose offset changed in GCC 4.4
> diff --git gcc/c/c-typeck.c gcc/c/c-typeck.c
> index 91735b5..635b568 100644
> --- gcc/c/c-typeck.c
> +++ gcc/c/c-typeck.c
> @@ -7978,7 +7978,7 @@ add_pending_init (location_t loc, tree purpose, tree
> value, tree origtype,
> if (!implicit)
> {
> if (TREE_SIDE_EFFECTS (p->value))
> - warning_init (loc, 0,
> + warning_init (loc, OPT_Woverride_init_side_effects,
> "initialized field with side-effects "
> "overwritten");
> else if (warn_override_init)
> @@ -8008,7 +8008,7 @@ add_pending_init (location_t loc, tree purpose, tree
> value, tree origtype,
> if (!implicit)
> {
> if (TREE_SIDE_EFFECTS (p->value))
> - warning_init (loc, 0,
> + warning_init (loc, OPT_Woverride_init_side_effects,
> "initialized field with side-effects "
> "overwritten");
> else if (warn_override_init)
> @@ -8540,7 +8540,7 @@ output_init_element (location_t loc, tree value, tree
> origtype,
> if (!implicit)
> {
> if (TREE_SIDE_EFFECTS (constructor_elements->last ().value))
> - warning_init (loc, 0,
> + warning_init (loc, OPT_Woverride_init_side_effects,
> "initialized field with side-effects overwritten");
> else if (warn_override_init)
> warning_init (loc, OPT_Woverride_init,
> diff --git gcc/doc/invoke.texi gcc/doc/invoke.texi
> index a939ff7..ff2ff24 100644
> --- gcc/doc/invoke.texi
> +++ gcc/doc/invoke.texi
> @@ -266,6 +266,7 @@ Objective-C and Objective-C++ Dialects}.
> -Wmissing-field-initializers -Wmissing-include-dirs @gol
> -Wno-multichar -Wnonnull
> -Wnormalized=@r{[}none@r{|}id@r{|}nfc@r{|}nfkc@r{]} @gol
> -Wodr -Wno-overflow -Wopenmp-simd @gol
> +-Woverride-init-side-effects @gol
> -Woverlength-strings -Wpacked -Wpacked-bitfield-compat -Wpadded @gol
> -Wparentheses -Wpedantic-ms-format -Wno-pedantic-ms-format @gol
> -Wpointer-arith -Wno-pointer-to-int-cast @gol
> @@ -5177,6 +5178,13 @@ This warning is included in @option{-Wextra}. To get
> other
> @option{-Wextra} warnings without this one, use @option{-Wextra
> -Wno-override-init}.
>
> +@item -Woverride-init-side-effects @r{(C and Objective-C only)}
> +@opindex Woverride-init-side-effects
> +@opindex Wno-override-init-side-effects
> +Warn if an initialized field with side effects is overridden when
> +using designated initializers (@pxref{Designated Inits, , Designated
> +Initializers}). This warning is enabled by default.
> +
> @item -Wpacked
> @opindex Wpacked
> @opindex Wno-packed
> diff --git gcc/testsuite/gcc.dg/Woverride-init-side-effects-1.c
> gcc/testsuite/gcc.dg/Woverride-init-side-effects-1.c
> index e69de29..50f198d 100644
> --- gcc/testsuite/gcc.dg/Woverride-init-side-effects-1.c
> +++ gcc/testsuite/gcc.dg/Woverride-init-side-effects-1.c
> @@ -0,0 +1,25 @@
> +/* PR c/64918 */
> +/* { dg-do compile } */
> +/* { dg-options "" } */
> +
> +struct S { int m, n; };
> +union U { short s; long int l; };
> +
> +void
> +foo (int i)
> +{
> + int a[] = {
> + [0] = ++i,
> + [1] = i,
> + [0] = 42 /* { dg-warning "initialized field with side-effects
> overwritten" } */
> + };
> + struct S s = {
> + .n = ++i,
> + .m = i,
> + .n = i /* { dg-warning "initialized field with side-effects
> overwritten" } */
> + };
> + union U u = {
> + .s = i--,
> + .l = 42 /* { dg-warning "initialized field with side-effects
> overwritten" } */
> + };
> +}
> diff --git gcc/testsuite/gcc.dg/Woverride-init-side-effects-2.c
> gcc/testsuite/gcc.dg/Woverride-init-side-effects-2.c
> index e69de29..a64e96a 100644
> --- gcc/testsuite/gcc.dg/Woverride-init-side-effects-2.c
> +++ gcc/testsuite/gcc.dg/Woverride-init-side-effects-2.c
> @@ -0,0 +1,25 @@
> +/* PR c/64918 */
> +/* { dg-do compile } */
> +/* { dg-options "-Wno-override-init-side-effects" } */
> +
> +struct S { int m, n; };
> +union U { short s; long int l; };
> +
> +void
> +foo (int i)
> +{
> + int a[] = {
> + [0] = ++i,
> + [1] = i,
> + [0] = 42
> + };
> + struct S s = {
> + .n = ++i,
> + .m = i,
> + .n = i
> + };
> + union U u = {
> + .s = i--,
> + .l = 42
> + };
> +}
>
> Marek
Marek
