Here the problem is that we issue a bogus "missing initializer" warning
even for zero-initializer "{ 0 }". So in case we're sure we have such
a zero-initializer, suppress the warning. If the constructor has a single
element which is not zero, don't set anything; it might be a constructor
from another init level, which is checked at a different time.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2015-01-29 Marek Polacek <pola...@redhat.com>
PR c/64709
* c-typeck.c (pop_init_level): If constructor_elements has
exactly one element with integer_zerop value, set constructor_zeroinit
to 1. Remove braces around warning_init call.
* gcc.dg/pr64709.c: New test.
--- gcc/c/c-typeck.c.jj 2015-01-27 09:13:05.091753264 +0100
+++ gcc/c/c-typeck.c 2015-01-29 19:01:30.841668899 +0100
@@ -7557,20 +7557,28 @@ pop_init_level (location_t loc, int impl
}
}
- /* Initialization with { } counts as zeroinit. */
- if (vec_safe_length (constructor_elements) == 0)
- constructor_zeroinit = 1;
- /* If the constructor has more than one element, it can't be { 0 }. */
- else if (vec_safe_length (constructor_elements) != 1)
- constructor_zeroinit = 0;
+ switch (vec_safe_length (constructor_elements))
+ {
+ case 0:
+ /* Initialization with { } counts as zeroinit. */
+ constructor_zeroinit = 1;
+ break;
+ case 1:
+ /* This might be zeroinit as well. */
+ if (integer_zerop ((*constructor_elements)[0].value))
+ constructor_zeroinit = 1;
+ break;
+ default:
+ /* If the constructor has more than one element, it can't be { 0 }. */
+ constructor_zeroinit = 0;
+ break;
+ }
/* Warn when some structs are initialized with direct aggregation. */
if (!implicit && found_missing_braces && warn_missing_braces
&& !constructor_zeroinit)
- {
- warning_init (loc, OPT_Wmissing_braces,
- "missing braces around initializer");
- }
+ warning_init (loc, OPT_Wmissing_braces,
+ "missing braces around initializer");
/* Warn when some struct elements are implicitly initialized to zero. */
if (warn_missing_field_initializers
--- gcc/testsuite/gcc.dg/pr64709.c.jj 2015-01-29 19:00:37.816566266 +0100
+++ gcc/testsuite/gcc.dg/pr64709.c 2015-01-29 19:00:32.675653268 +0100
@@ -0,0 +1,10 @@
+/* PR c/64709 */
+/* { dg-do compile } */
+/* { dg-options "-Wmissing-field-initializers" } */
+
+struct S { int a, b; };
+void
+foo (void)
+{
+ struct S s[] = { { 1, 2 }, { 0 } }; /* { dg-bogus "missing initializer for
field" } */
+}
Marek
