[v3] c++: designated init of char array by string constant [PR55227]
Commit Message
V3 addresses Jason's review point - it.undoes unnecessary variable renames
(back from arr_init to str_init)
Also address "FIXME: this code is duplicated from reshape_init" in
cp_complete_array_type by always calling reshape_init on init-list.
PR c++/55227
gcc/cp/ChangeLog:
* decl.c (reshape_init_r): Only call has_designator_check when
first_initializer_p or for the inner constructor element.
(cp_complete_array_type): Call reshape_init on braced-init-list.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/desig20.C: New test.
---
gcc/cp/decl.c | 28 ++++++++------------
gcc/testsuite/g++.dg/cpp2a/desig20.C | 48 +++++++++++++++++++++++++++++++++++
2 files changed, 58 insertions(+), 18 deletions(-)
+{
+ return t<void>();
+}
Comments
Attached
(the cut n paste looks like it removed some whitespace formatting)
On 1/17/22 14:29, will wray wrote:
> Attached
> (the cut n paste looks like it removed some whitespace formatting)
Pushed, thanks! I incorporated the introduction from your initial email
in the commit message.
Jason
@@ -6811,6 +6811,7 @@ reshape_init_r (tree type, reshape_iter *d, tree
first_initializer_p,
{
tree str_init = init;
tree stripped_str_init = stripped_init;
+ reshape_iter stripd = {};
/* Strip one level of braces if and only if they enclose a single
element (as allowed by [dcl.init.string]). */
@@ -6818,7 +6819,8 @@ reshape_init_r (tree type, reshape_iter *d, tree
first_initializer_p,
&& TREE_CODE (stripped_str_init) == CONSTRUCTOR
&& CONSTRUCTOR_NELTS (stripped_str_init) == 1)
{
- str_init = (*CONSTRUCTOR_ELTS (stripped_str_init))[0].value;
+ stripd.cur = CONSTRUCTOR_ELT (stripped_str_init, 0);
+ str_init = stripd.cur->value;
stripped_str_init = tree_strip_any_location_wrapper (str_init);
}
@@ -6827,7 +6829,8 @@ reshape_init_r (tree type, reshape_iter *d, tree
first_initializer_p,
array types (one value per array element). */
if (TREE_CODE (stripped_str_init) == STRING_CST)
{
- if (has_designator_problem (d, complain))
+ if ((first_initializer_p && has_designator_problem (d, complain))
+ || (stripd.cur && has_designator_problem (&stripd, complain)))
return error_mark_node;
d->cur++;
return str_init;
@@ -9544,22 +9547,11 @@ cp_complete_array_type (tree *ptype, tree
initial_value, bool do_default)
if (initial_value)
{
/* An array of character type can be initialized from a
- brace-enclosed string constant.
-
- FIXME: this code is duplicated from reshape_init. Probably
- we should just call reshape_init here? */
- if (char_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (*ptype)))
- && TREE_CODE (initial_value) == CONSTRUCTOR
- && !vec_safe_is_empty (CONSTRUCTOR_ELTS (initial_value)))
- {
- vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (initial_value);
- tree value = (*v)[0].value;
- STRIP_ANY_LOCATION_WRAPPER (value);
-
- if (TREE_CODE (value) == STRING_CST
- && v->length () == 1)
- initial_value = value;
- }
+ brace-enclosed string constant so call reshape_init to
+ remove the optional braces from a braced string literal. */
+ if (BRACE_ENCLOSED_INITIALIZER_P (initial_value))
+ initial_value = reshape_init (*ptype, initial_value,
+ tf_warning_or_error);
/* If any of the elements are parameter packs, we can't actually
complete this type now because the array size is dependent. */
b/gcc/testsuite/g++.dg/cpp2a/desig20.C
new file mode 100644
@@ -0,0 +1,48 @@
+// PR c++/55227
+// Test designated initializer for char array by string constant
+
+// { dg-options "" }
+
+struct C {char a[2];};
+
+/* Case a, designated, unbraced, string-literal of the exact same size
+ as the initialized char array; valid and accepted before and after. */
+C a = {.a="a"};
+
+/* Cases b,c,d, designated, braced or mimatched-size, string literal,
+ previously rejected; "C99 designator 'a' outside aggregate initializer". */
+C b = {.a=""};
+C c = {.a={""}};
+C d = {.a={"a"}};
+
+/* Case e, designated char array field and braced, designated array element(s)
+ (with GNU [N]= extension) valid and accepted before and after. */
+C e = {.a={[0]='a'}};
+
+/* Cases f,g,h, braced string literal, 'designated' within inner braces;
+ invalid, previously accepted as positional with 'designator' ignored. */
+C f = {{[0]="a"}}; // { dg-error "C99 designator .0. outside
aggregate initializer" }
+C g = {{.a="a"}}; // { dg-error "C99 designator .a. outside aggregate
initializer" }
+C h = {{.b="a"}}; // { dg-error "C99 designator .b. outside aggregate
initializer" }
+
+char a2[][10] = { [0] = { "aaa" } };
+
+struct D { C c; int a[8]; };
+
+D x = { .c {.a={"a"}}, .a={1,2,3,4,5,6,7,8} };
+
+struct A { union { int a; char c[4]; }; };
+
+A non = { .c = "c++" };
+
+template <class T>
+void t()
+{
+ C ca[] = { {.a=""}, {.a={""}}, };
+
+}
+
+void u()