Re: [C PATCH] Better column info for initializers (PR c/60139)
On Thu, May 01, 2014 at 11:55:38PM +, Joseph S. Myers wrote:
On Fri, 25 Apr 2014, Marek Polacek wrote:
Another minor fix: use loc instead of input_location. Also add
missing OPT_Wpedantic.
Why do you say it's missing? A default pedwarn generally means this is
dubious code, not allowed by ISO C, but we don't want to make it a hard
error (and the trend is more to making such things hard errors, rather
than limiting them to -pedantic).
For the *first* such change (not computable at load time), I think it's
already conditional on (pedantic !flag_isoc99), based on the setting of
require_constant_elements, and so using OPT_Wpedantic is appropriate. But
I think the second represents an undesirable change to how the compiler
behaves - code such as
int f();
int a = 1 ? 1 : f();
*should* be diagnosed by default rather than needing -pedantic. If you
Yeah, this case is even now diagnosted by default (for this we warn in
digest_init).
think this case also only affects for form of diagnostics that were
already only given if pedantic, please explain further why this is the
case.
Right. I added OPT_Wpedantic to second pedwarn_init (initializer
element is not a constant expression), because this warning was
output only when using -pedantic and C89, but it didn't say [-Wpedantic],
thus it looked like the warning is enabled by default. The reason
is that this pedwarn is guarded by require_constant_elements, which
is, as you said, dependent on (pedantic !flag_isoc99) in
start_init. Just for the record, this pedwarn warns e.g. on
double sin (double);
void
fn (int *p)
{
double d[] = { sin (1.0) };
}
So the patch doesn't suppress any warnings, it only adds
[-Wpedantic] where it should be (there might be other cases where
[-Wpedantic] is missing).
Marek
Re: [C PATCH] Better column info for initializers (PR c/60139)
On Fri, 25 Apr 2014, Marek Polacek wrote: Another minor fix: use loc instead of input_location. Also add missing OPT_Wpedantic. Why do you say it's missing? A default pedwarn generally means this is dubious code, not allowed by ISO C, but we don't want to make it a hard error (and the trend is more to making such things hard errors, rather than limiting them to -pedantic). For the *first* such change (not computable at load time), I think it's already conditional on (pedantic !flag_isoc99), based on the setting of require_constant_elements, and so using OPT_Wpedantic is appropriate. But I think the second represents an undesirable change to how the compiler behaves - code such as int f(); int a = 1 ? 1 : f(); *should* be diagnosed by default rather than needing -pedantic. If you think this case also only affects for form of diagnostics that were already only given if pedantic, please explain further why this is the case. -- Joseph S. Myers jos...@codesourcery.com
Re: [C PATCH] Better column info for initializers (PR c/60139)
On 04/25/2014 08:44 AM, Marek Polacek wrote: 2014-04-25 Marek Polacek pola...@redhat.com PR c/60139 * c-typeck.c (output_init_element): Pass OPT_Wpedantic to pedwarn and pedwarn_init. Use loc insted of input_location. * gcc.dg/pr60139.c: New test. Ok. r~
[C PATCH] Better column info for initializers (PR c/60139)
Another minor fix: use loc instead of input_location. Also add
missing OPT_Wpedantic.
After this is in, my plan is to make pedwarn_init and error_init
static (I already have a patch for that) and then add location
argument to error_init and pass proper location to it, and to
pedwarn_init as well -- that should greatly improve initializer
warnings/errors.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2014-04-25 Marek Polacek pola...@redhat.com
PR c/60139
* c-typeck.c (output_init_element): Pass OPT_Wpedantic to pedwarn
and pedwarn_init. Use loc insted of input_location.
* gcc.dg/pr60139.c: New test.
diff --git gcc/c/c-typeck.c gcc/c/c-typeck.c
index 62c72df..a82801f 100644
--- gcc/c/c-typeck.c
+++ gcc/c/c-typeck.c
@@ -8255,12 +8255,12 @@ output_init_element (location_t loc, tree value, tree
origtype,
value = error_mark_node;
}
else if (require_constant_elements)
- pedwarn (input_location, 0,
+ pedwarn (loc, OPT_Wpedantic,
initializer element is not computable at load time);
}
else if (!maybe_const
(require_constant_value || require_constant_elements))
-pedwarn_init (input_location, 0,
+pedwarn_init (loc, OPT_Wpedantic,
initializer element is not a constant expression);
/* Issue -Wc++-compat warnings about initializing a bitfield with
diff --git gcc/testsuite/gcc.dg/pr60139.c gcc/testsuite/gcc.dg/pr60139.c
index e69de29..a63d8b5 100644
--- gcc/testsuite/gcc.dg/pr60139.c
+++ gcc/testsuite/gcc.dg/pr60139.c
@@ -0,0 +1,14 @@
+/* PR c/60139 */
+/* { dg-do compile } */
+/* { dg-options -Wpedantic } */
+/* { dg-prune-output .*near initialization for.* } */
+
+double sin (double);
+void
+fn (int *p)
+{
+ int **a[] = { p, /* { dg-warning 17:initializer element is not computable
at load time } */
+ (void *) 0, p }; /* { dg-warning 28:initializer element is
not computable at load time } */
+ double d[] = { sin (1.0), /* { dg-warning 18:initializer element is not a
constant expression } */
+ 8.8, sin (1.0), 2.6 }; /* { dg-warning 23:initializer
element is not a constant expression } */
+}
Marek
