On Sat, Sep 07, 2024 at 10:17:14PM +0100, Peter Frost wrote:
> v2 Patch:
> * adds proper changelog text
> * fixes typo in c.opt
>
> Currently the behaviour of Wmissing-field-initializers is inconsistent
> between C and C++. The C warning assumes that missing designated
> initializers are deliberate, and does not warn. The C++ warning does warn
> for missing designated initializers.
>
> This patch changes the behaviour of Wmissing-field-initializers to
> universally not warn about missing designated initializers, and adds a new
> warning for specifically for missing designated initializers.
>
> NOTE TO MAINTAINERS: This is my first gcc contribution, so I don't have
> git write access.
Thanks for the patch and sorry for the delay.
New options need to be documented in doc/invoke.texi; you can follow
-Wmissing-field-initializers in this case.
> Successfully tested on x86_64-pc-linux-gnu.
>
> PR c/39589
>
> gcc/c-family/ChangeLog:
>
> * c.opt: Added new option Wmissing-designated-initializers, enabled by
> Wextra
Usually we'd say:
* c.opt (Wmissing-designated-initializers): New option.
> gcc/c/ChangeLog:
>
> * c-typeck.cc (pop_init_level): Generate warning for missing designated
> initializers rather than always ignore
Please add a '.' at the end.
> gcc/cp/ChangeLog:
>
> * typeck2.cc (process_init_constructor_record): Add check if missing
> initializer is designated, warn as appropriate
Here too.
> gcc/testsuite/ChangeLog:
>
> * g++.dg/diagnostic/base.C: Change flags
> * gcc.dg/20011021-1.c: Fix test, missing designated initializers can
> generate a warning now
> * gcc.dg/missing-field-init-1.c: Change flags
> * gcc.dg/pr60784.c: Change flags
Here too.
> * g++.dg/warn/missing-designated-initializers-1.C: New test.
> * g++.dg/warn/missing-designated-initializers-2.C: New test.
> * gcc.dg/missing-designated-initializers-1.c: New test.
> * gcc.dg/missing-designated-initializers-2.c: New test.
>
>
> ---
> gcc/c-family/c.opt | 4 +++
> gcc/c/c-typeck.cc | 36 +++++++++++--------
> gcc/cp/typeck2.cc | 20 ++++++++---
> gcc/testsuite/g++.dg/diagnostic/base.C | 4 +--
> .../warn/missing-designated-initializers-1.C | 11 ++++++
> .../warn/missing-designated-initializers-2.C | 11 ++++++
> gcc/testsuite/gcc.dg/20011021-1.c | 4 +--
> .../missing-designated-initializers-1.c | 13 +++++++
> .../missing-designated-initializers-2.c | 13 +++++++
> gcc/testsuite/gcc.dg/missing-field-init-1.c | 2 +-
> gcc/testsuite/gcc.dg/pr60784.c | 2 +-
> 11 files changed, 96 insertions(+), 24 deletions(-)
> create mode 100644
> gcc/testsuite/g++.dg/warn/missing-designated-initializers-1.C
> create mode 100644
> gcc/testsuite/g++.dg/warn/missing-designated-initializers-2.C
> create mode 100644 gcc/testsuite/gcc.dg/missing-designated-initializers-1.c
> create mode 100644 gcc/testsuite/gcc.dg/missing-designated-initializers-2.c
>
> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
> index 491aa02e1a3..81e52f1417e 100644
> --- a/gcc/c-family/c.opt
> +++ b/gcc/c-family/c.opt
> @@ -977,6 +977,10 @@ Wmissing-field-initializers
> C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning
> EnabledBy(Wextra)
> Warn about missing fields in struct initializers.
>
> +Wmissing-designated-initializers
> +C ObjC C++ ObjC++ Var(warn_missing_designated_initializers) Warning
> EnabledBy(Wextra)
> +Warn about missing designated initializers in struct initializers.
> +
Since you're adding a new option, c.opt.urls needs to be regenerated. All you
should need for that is to:
$ make html
$ make regenerate-opt-urls
in the builddir. And I think you need to enable all languages when configuring
GCC for that to work. Let me know if you're having trouble with this.
> Wmissing-format-attribute
> C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
> ;
> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
> index 094e41fa202..72b544e8f67 100644
> --- a/gcc/c/c-typeck.cc
> +++ b/gcc/c/c-typeck.cc
> @@ -9795,7 +9795,7 @@ pop_init_level (location_t loc, int implicit,
> }
>
> /* Warn when some struct elements are implicitly initialized to zero. */
> - if (warn_missing_field_initializers
> + if ((warn_missing_field_initializers ||
> warn_missing_designated_initializers)
> && constructor_type
> && TREE_CODE (constructor_type) == RECORD_TYPE
> && constructor_unfilled_fields)
> @@ -9806,21 +9806,29 @@ pop_init_level (location_t loc, int implicit,
> || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
> constructor_unfilled_fields = DECL_CHAIN
> (constructor_unfilled_fields);
>
> - if (constructor_unfilled_fields
> - /* Do not warn if this level of the initializer uses member
> - designators; it is likely to be deliberate. */
> - && !constructor_designated
> - /* Do not warn about initializing with { 0 } or with { }. */
> - && !constructor_zeroinit)
> - {
> - if (warning_at (input_location, OPT_Wmissing_field_initializers,
> + if (constructor_unfilled_fields
> + /* Do not warn about initializing with { 0 } or with { }. */
> + && !constructor_zeroinit)
> + {
> + if (!constructor_designated)
> + {
> + if (warning_at (input_location,
> OPT_Wmissing_field_initializers,
> "missing initializer for field %qD of %qT",
> - constructor_unfilled_fields,
> - constructor_type))
> - inform (DECL_SOURCE_LOCATION (constructor_unfilled_fields),
> + constructor_unfilled_fields, constructor_type))
> + inform (DECL_SOURCE_LOCATION
> (constructor_unfilled_fields),
> + "%qD declared here", constructor_unfilled_fields);
> + }
> + else if (warn_missing_designated_initializers)
I think this could be just "else".
> + {
> + if (warning_at (
> + input_location,
> OPT_Wmissing_designated_initializers,
> + "missing designated initializer for field %qD of
> %qT",
> + constructor_unfilled_fields, constructor_type))
> + inform (DECL_SOURCE_LOCATION
> (constructor_unfilled_fields),
The formatting should be more like:
if (warning_at (input_location, OPT_Wmissing_designated_initializers,
"..."))
inform (...);
> "%qD declared here", constructor_unfilled_fields);
> - }
> - }
> + }
> + }
> + }
>
> /* Pad out the end of the structure. */
> if (p->replacement_value.value)
> diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc
> index 30a6fbe95c9..6d21caf53d7 100644
> --- a/gcc/cp/typeck2.cc
> +++ b/gcc/cp/typeck2.cc
> @@ -1822,8 +1822,14 @@ process_init_constructor_record (tree type, tree init,
> int nested, int flags,
> if ((complain & tf_warning)
> && !cp_unevaluated_operand
> && !EMPTY_CONSTRUCTOR_P (init))
> - warning (OPT_Wmissing_field_initializers,
> - "missing initializer for member %qD", field);
> + {
> + if (CONSTRUCTOR_IS_DESIGNATED_INIT (init))
> + warning (OPT_Wmissing_designated_initializers,
> + "missing designated initializer for member %qD", field);
> + else
> + warning (OPT_Wmissing_field_initializers,
> + "missing initializer for member %qD", field);
> + }
Formatting: the warning calls seem to be indented incorrectly.
The convention is:
if (foo)
warning (...,
"foo");
else
warning (...,
"bar");
> }
> else
> {
> @@ -1853,8 +1859,14 @@ process_init_constructor_record (tree type, tree init,
> int nested, int flags,
> && !cp_unevaluated_operand
> && !EMPTY_CONSTRUCTOR_P (init)
> && !is_really_empty_class (fldtype, /*ignore_vptr*/false))
> - warning (OPT_Wmissing_field_initializers,
> - "missing initializer for member %qD", field);
> + {
> + if (CONSTRUCTOR_IS_DESIGNATED_INIT (init))
> + warning (OPT_Wmissing_designated_initializers,
> + "missing designated initializer for member %qD", field);
> + else
> + warning (OPT_Wmissing_field_initializers,
> + "missing initializer for member %qD", field);
> + }
Here too.
>
> if (!zero_init_p (fldtype) || skipped < 0)
> {
> diff --git a/gcc/testsuite/g++.dg/diagnostic/base.C
> b/gcc/testsuite/g++.dg/diagnostic/base.C
> index 1540414072e..d8c644f78f5 100644
> --- a/gcc/testsuite/g++.dg/diagnostic/base.C
> +++ b/gcc/testsuite/g++.dg/diagnostic/base.C
> @@ -1,6 +1,6 @@
> // PR c++/110745
> // { dg-do compile { target c++17 } }
> -// { dg-options "-Wmissing-field-initializers" }
> +// { dg-options "-Wmissing-designated-initializers" }
>
> struct B { int i; };
> struct D : B {
> @@ -11,6 +11,6 @@ struct D : B {
> int
> main ()
> {
> - D d = {.x=1, .y=2}; // { dg-warning "missing initializer for member
> .D::B." }
> + D d = {.x=1, .y=2}; // { dg-warning "missing designated initializer for
> member .D::B." }
> (void)d;
> }
> diff --git a/gcc/testsuite/g++.dg/warn/missing-designated-initializers-1.C
> b/gcc/testsuite/g++.dg/warn/missing-designated-initializers-1.C
> new file mode 100644
> index 00000000000..86afafc5e9b
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/warn/missing-designated-initializers-1.C
> @@ -0,0 +1,11 @@
Please add
/* PR c/39589 */
to the new tests.
> +/* { dg-do compile } */
> +/* { dg-options "-Wextra -Wmissing-designated-initializers" } */
> +
> +struct s { int a, b, c; };
> +struct s s1 = { .a = 1, .b = 2, .c = 3 };
> +struct s s2 = { .a = 1, .b = 2 }; /* { dg-warning "missing designated
> initializer" } */
> +struct s s3 = { .a = 1 }; /* { dg-warning "missing designated initializer" }
> */
> +
> +struct s s6[] = { { .a = 1, .b = 2, .c = 3 }, { .a = 4 } }; /* { dg-warning
> "missing designated initializer" } */
> +struct s s7[] = { { .a = 1 }, { .a = 2, .b = 3, .c = 4 } }; /* { dg-warning
> "missing designated initializer" } */
> +struct s s8[] = { { 1, 2, 3 }, { .a = 4 } }; /* { dg-warning "missing
> designated initializer" } */
> diff --git a/gcc/testsuite/g++.dg/warn/missing-designated-initializers-2.C
> b/gcc/testsuite/g++.dg/warn/missing-designated-initializers-2.C
> new file mode 100644
> index 00000000000..b47af7baac5
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/warn/missing-designated-initializers-2.C
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wextra -Wno-missing-designated-initializers" } */
> +
> +struct s { int a, b, c; };
> +struct s s1 = { .a = 1, .b = 2, .c = 3 };
> +struct s s2 = { .a = 1, .b = 2 }; /* { dg-bogus "missing designated
> initializer" } */
> +struct s s3 = { .a = 1 }; /* { dg-bogus "missing designated initializer" } */
> +
> +struct s s6[] = { { .a = 1, .b = 2, .c = 3 }, { .a = 4 } }; /* { dg-bogus
> "missing designated initializer" } */
> +struct s s7[] = { { .a = 1 }, { .a = 2, .b = 3, .c = 4 } }; /* { dg-bogus
> "missing designated initializer" } */
> +struct s s8[] = { { 1, 2, 3 }, { .a = 4 } }; /* { dg-bogus "missing
> designated initializer" } */
> diff --git a/gcc/testsuite/gcc.dg/20011021-1.c
> b/gcc/testsuite/gcc.dg/20011021-1.c
> index 2d567a75381..66964541d05 100644
> --- a/gcc/testsuite/gcc.dg/20011021-1.c
> +++ b/gcc/testsuite/gcc.dg/20011021-1.c
> @@ -29,7 +29,7 @@ struct multilevel
>
> struct t T0 = { 1 }; /* { dg-warning "missing init" } */
>
> -struct t T1 = { .a = 1 }; /* { dg-bogus "(missing|near) init" } */
> +struct t T1 = { .a = 1 }; /* { dg-warning "missing designated
> initializer" } */
>
> union u U0 = { 1 }; /* { dg-warning "initialization of union" } */
> union u U1 = { .i = 1 }; /* { dg-bogus "initialization of union" } */
> @@ -37,7 +37,7 @@ union u U1 = { .i = 1 }; /* { dg-bogus "initialization
> of union" } */
> struct multilevel M =
> {
> 12,
> - { .b = 3 }, /* { dg-bogus "missing init" } */
> + { .b = 3 }, /* { dg-warning "missing designated
> initializer" } */
> { 4 }, /* { dg-warning "initialization of union" } */
> { .n = 9 }, /* { dg-bogus "initialization of union"
> } */
> /* "string here" */
> diff --git a/gcc/testsuite/gcc.dg/missing-designated-initializers-1.c
> b/gcc/testsuite/gcc.dg/missing-designated-initializers-1.c
> new file mode 100644
> index 00000000000..817386785f3
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/missing-designated-initializers-1.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wextra -Wmissing-designated-initializers" } */
> +
> +struct s { int a, b, c; };
> +struct s s1 = { .a = 1, .b = 2, .c = 3 };
> +struct s s2 = { .a = 1, .b = 2 }; /* { dg-warning "missing designated
> initializer" } */
> +struct s s3 = { .a = 1 }; /* { dg-warning "missing designated initializer" }
> */
> +struct s s4 = { .a = 1, 2 }; /* { dg-warning "missing designated
> initializer" } */
> +struct s s5 = { .a = 1, 2, 3 }; /* { dg-bogus "missing designated
> initializer" } */
> +
> +struct s s6[] = { { .a = 1, .b = 2, .c = 3 }, { .a = 4 } }; /* { dg-warning
> "missing designated initializer" } */
> +struct s s7[] = { { .a = 1 }, { .a = 2, .b = 3, .c = 4 } }; /* { dg-warning
> "missing designated initializer" } */
> +struct s s8[] = { { 1, 2, 3 }, { .a = 4 } }; /* { dg-warning "missing
> designated initializer" } */
> diff --git a/gcc/testsuite/gcc.dg/missing-designated-initializers-2.c
> b/gcc/testsuite/gcc.dg/missing-designated-initializers-2.c
> new file mode 100644
> index 00000000000..dc2c6bb51f3
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/missing-designated-initializers-2.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wextra -Wno-missing-designated-initializers" } */
> +
> +struct s { int a, b, c; };
> +struct s s1 = { .a = 1, .b = 2, .c = 3 };
> +struct s s2 = { .a = 1, .b = 2 }; /* { dg-bogus "missing designated
> initializer" } */
> +struct s s3 = { .a = 1 }; /* { dg-bogus "missing designated initializer" } */
> +struct s s4 = { .a = 1, 2 }; /* { dg-bogus "missing designated initializer"
> } */
> +struct s s5 = { .a = 1, 2, 3 }; /* { dg-bogus "missing designated
> initializer" } */
> +
> +struct s s6[] = { { .a = 1, .b = 2, .c = 3 }, { .a = 4 } }; /* { dg-bogus
> "missing designated initializer" } */
> +struct s s7[] = { { .a = 1 }, { .a = 2, .b = 3, .c = 4 } }; /* { dg-bogus
> "missing designated initializer" } */
> +struct s s8[] = { { 1, 2, 3 }, { .a = 4 } }; /* { dg-bogus "missing
> designated initializer" } */
> diff --git a/gcc/testsuite/gcc.dg/missing-field-init-1.c
> b/gcc/testsuite/gcc.dg/missing-field-init-1.c
> index 5f32b021f0a..cd43fcc4f06 100644
> --- a/gcc/testsuite/gcc.dg/missing-field-init-1.c
> +++ b/gcc/testsuite/gcc.dg/missing-field-init-1.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-Wextra -Wno-missing-field-initializers -std=c99" } */
> +/* { dg-options "-Wextra -Wno-missing-field-initializers
> -Wno-missing-designated-initializers -std=c99" } */
>
> struct s { int a, b, c; };
> struct s s1 = { 1, 2, 3 };
> diff --git a/gcc/testsuite/gcc.dg/pr60784.c b/gcc/testsuite/gcc.dg/pr60784.c
> index 82b512f7c2e..60532831f4f 100644
> --- a/gcc/testsuite/gcc.dg/pr60784.c
> +++ b/gcc/testsuite/gcc.dg/pr60784.c
> @@ -1,6 +1,6 @@
> /* PR c/60784 */
> /* { dg-do compile } */
> -/* { dg-options "-Wextra -std=c99" } */
> +/* { dg-options "-Wextra -Wno-missing-designated-initializers -std=c99" } */
>
> struct A { int i, j; };
> struct B { struct A a; } b1 = { .a.i = 1, .a.j = 1 };
> --
> 2.39.2
>
Marek
