Support for constructing composite type for structs and unions
in C23.
gcc/c:
* c-typeck.cc (composite_type_internal): Adapted from
composite_type to support structs and unions.
(composite_type): New wrapper function.
(build_conditional_operator): Return composite type.
gcc/testsuite:
* gcc.dg/c2x-tag-composite-1.c: New test.
* gcc.dg/c2x-tag-composite-2.c: New test.
* gcc.dg/c2x-tag-composite-3.c: New test.
* gcc.dg/c2x-tag-composite-4.c: New test.
---
gcc/c/c-typeck.cc | 114 +++++++++++++++++----
gcc/testsuite/gcc.dg/c2x-tag-composite-1.c | 26 +++++
gcc/testsuite/gcc.dg/c2x-tag-composite-2.c | 16 +++
gcc/testsuite/gcc.dg/c2x-tag-composite-3.c | 17 +++
gcc/testsuite/gcc.dg/c2x-tag-composite-4.c | 21 ++++
5 files changed, 176 insertions(+), 18 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/c2x-tag-composite-1.c
create mode 100644 gcc/testsuite/gcc.dg/c2x-tag-composite-2.c
create mode 100644 gcc/testsuite/gcc.dg/c2x-tag-composite-3.c
create mode 100644 gcc/testsuite/gcc.dg/c2x-tag-composite-4.c
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 2489fa1e3d1..357367eab09 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -381,8 +381,15 @@ build_functype_attribute_variant (tree ntype, tree otype,
tree attrs)
nonzero; if that isn't so, this may crash. In particular, we
assume that qualifiers match. */
+struct composite_cache {
+ tree t1;
+ tree t2;
+ tree composite;
+ struct composite_cache* next;
+};
+
tree
-composite_type (tree t1, tree t2)
+composite_type_internal (tree t1, tree t2, struct composite_cache* cache)
{
enum tree_code code1;
enum tree_code code2;
@@ -425,7 +432,8 @@ composite_type (tree t1, tree t2)
{
tree pointed_to_1 = TREE_TYPE (t1);
tree pointed_to_2 = TREE_TYPE (t2);
- tree target = composite_type (pointed_to_1, pointed_to_2);
+ tree target = composite_type_internal (pointed_to_1,
+ pointed_to_2, cache);
t1 = build_pointer_type_for_mode (target, TYPE_MODE (t1), false);
t1 = build_type_attribute_variant (t1, attributes);
return qualify_type (t1, t2);
@@ -433,7 +441,8 @@ composite_type (tree t1, tree t2)
case ARRAY_TYPE:
{
- tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
+ tree elt = composite_type_internal (TREE_TYPE (t1), TREE_TYPE (t2),
+ cache);
int quals;
tree unqual_elt;
tree d1 = TYPE_DOMAIN (t1);
@@ -501,9 +510,61 @@ composite_type (tree t1, tree t2)
return build_type_attribute_variant (t1, attributes);
}
- case ENUMERAL_TYPE:
case RECORD_TYPE:
case UNION_TYPE:
+ if (flag_isoc2x && !comptypes_same_p (t1, t2))
+ {
+ gcc_checking_assert (COMPLETE_TYPE_P (t1) && COMPLETE_TYPE_P (t2));
+ gcc_checking_assert (comptypes (t1, t2));
+
+ /* If a composite type for these two types is already under
+ construction, return it. */
+
+ for (struct composite_cache *c = cache; c != NULL; c = c->next)
+ if (c->t1 == t1 && c->t2 == t2)
+ return c->composite;
+
+ /* Otherwise, create a new type node and link it into the cache. */
+
+ tree n = make_node (code1);
+ struct composite_cache cache2 = { t1, t2, n, cache };
+ cache = &cache2;
+
+ tree f1 = TYPE_FIELDS (t1);
+ tree f2 = TYPE_FIELDS (t2);
+ tree fields = NULL_TREE;
+
+ for (tree a = f1, b = f2; a && b;
+ a = DECL_CHAIN (a), b = DECL_CHAIN (b))
+ {
+ tree ta = TREE_TYPE (a);
+ tree tb = TREE_TYPE (b);
+
+ gcc_assert (DECL_NAME (a) == DECL_NAME (b));
+ gcc_assert (comptypes (ta, tb));
+
+ tree f = build_decl (input_location, FIELD_DECL, DECL_NAME (a),
+ composite_type_internal (ta, tb, cache));
+
+ DECL_FIELD_CONTEXT (f) = n;
+ DECL_CHAIN (f) = fields;
+ fields = f;
+ }
+
+ TYPE_NAME (n) = TYPE_NAME (t1);
+ TYPE_FIELDS (n) = nreverse (fields);
+ TYPE_ATTRIBUTES (n) = attributes;
+ layout_type (n);
+ n = build_type_attribute_variant (n, attributes);
+ n = qualify_type (n, t1);
+
+ gcc_checking_assert (comptypes (n, t1));
+ gcc_checking_assert (comptypes (n, t2));
+
+ return n;
+ }
+ /* FALLTHRU */
+ case ENUMERAL_TYPE:
if (attributes != NULL)
{
/* Try harder not to create a new aggregate type. */
@@ -518,7 +579,8 @@ composite_type (tree t1, tree t2)
/* Function types: prefer the one that specified arg types.
If both do, merge the arg types. Also merge the return types. */
{
- tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
+ tree valtype = composite_type_internal (TREE_TYPE (t1),
+ TREE_TYPE (t2), cache);
tree p1 = TYPE_ARG_TYPES (t1);
tree p2 = TYPE_ARG_TYPES (t2);
int len;
@@ -563,6 +625,16 @@ composite_type (tree t1, tree t2)
for (; p1 && p1 != void_list_node;
p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
{
+ tree mv1 = TREE_VALUE (p1);
+ if (mv1 && mv1 != error_mark_node
+ && TREE_CODE (mv1) != ARRAY_TYPE)
+ mv1 = TYPE_MAIN_VARIANT (mv1);
+
+ tree mv2 = TREE_VALUE (p2);
+ if (mv2 && mv2 != error_mark_node
+ && TREE_CODE (mv2) != ARRAY_TYPE)
+ mv2 = TYPE_MAIN_VARIANT (mv2);
+
/* A null type means arg type is not specified.
Take whatever the other function type has. */
if (TREE_VALUE (p1) == NULL_TREE)
@@ -583,10 +655,6 @@ composite_type (tree t1, tree t2)
&& TREE_VALUE (p1) != TREE_VALUE (p2))
{
tree memb;
- tree mv2 = TREE_VALUE (p2);
- if (mv2 && mv2 != error_mark_node
- && TREE_CODE (mv2) != ARRAY_TYPE)
- mv2 = TYPE_MAIN_VARIANT (mv2);
for (memb = TYPE_FIELDS (TREE_VALUE (p1));
memb; memb = DECL_CHAIN (memb))
{
@@ -596,8 +664,9 @@ composite_type (tree t1, tree t2)
mv3 = TYPE_MAIN_VARIANT (mv3);
if (comptypes (mv3, mv2))
{
- TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
- TREE_VALUE (p2));
+ TREE_VALUE (n) = composite_type_internal (TREE_TYPE
(memb),
+ TREE_VALUE
(p2),
+ cache);
pedwarn (input_location, OPT_Wpedantic,
"function types not truly compatible in ISO
C");
goto parm_done;
@@ -608,10 +677,6 @@ composite_type (tree t1, tree t2)
&& TREE_VALUE (p2) != TREE_VALUE (p1))
{
tree memb;
- tree mv1 = TREE_VALUE (p1);
- if (mv1 && mv1 != error_mark_node
- && TREE_CODE (mv1) != ARRAY_TYPE)
- mv1 = TYPE_MAIN_VARIANT (mv1);
for (memb = TYPE_FIELDS (TREE_VALUE (p2));
memb; memb = DECL_CHAIN (memb))
{
@@ -621,15 +686,17 @@ composite_type (tree t1, tree t2)
mv3 = TYPE_MAIN_VARIANT (mv3);
if (comptypes (mv3, mv1))
{
- TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
- TREE_VALUE (p1));
+ TREE_VALUE (n)
+ = composite_type_internal (TREE_TYPE (memb),
+ TREE_VALUE (p1),
+ cache);
pedwarn (input_location, OPT_Wpedantic,
"function types not truly compatible in ISO
C");
goto parm_done;
}
}
}
- TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2));
+ TREE_VALUE (n) = composite_type_internal (mv1, mv2, cache);
parm_done: ;
}
@@ -641,7 +708,13 @@ composite_type (tree t1, tree t2)
default:
return build_type_attribute_variant (t1, attributes);
}
+}
+tree
+composite_type (tree t1, tree t2)
+{
+ struct composite_cache cache = { };
+ return composite_type_internal (t1, t2, &cache);
}
/* Return the type of a conditional expression between pointers to
@@ -5480,6 +5553,11 @@ build_conditional_expr (location_t colon_loc, tree
ifexp, bool ifexp_bcp,
result_type = type2;
else if (code1 == POINTER_TYPE && code2 == NULLPTR_TYPE)
result_type = type1;
+ else if (RECORD_OR_UNION_TYPE_P (type1) && RECORD_OR_UNION_TYPE_P (type2)
+ && comptypes (TYPE_MAIN_VARIANT (type1),
+ TYPE_MAIN_VARIANT (type2)))
+ result_type = composite_type (TYPE_MAIN_VARIANT (type1),
+ TYPE_MAIN_VARIANT (type2));
if (!result_type)
{
diff --git a/gcc/testsuite/gcc.dg/c2x-tag-composite-1.c
b/gcc/testsuite/gcc.dg/c2x-tag-composite-1.c
new file mode 100644
index 00000000000..aae11f6cee2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-tag-composite-1.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c2x" } */
+
+void b(void)
+{
+ int n = 3;
+
+ extern struct f { char (*x)[3]; char (*y)[]; } q;
+ { extern struct f { char (*x)[]; char (*y)[4]; } q;
+ _Static_assert(3 == sizeof(*q.x), "");
+ _Static_assert(4 == sizeof(*q.y), "");
+ }
+ { extern struct f { char (*x)[2]; char (*y)[]; } q; (void)q; } /* {
dg-error "conflicting" } */
+
+ { struct f { char (*x)[n]; char (*y)[3]; }* qp = &q; (void)*qp; }
+ (void)q;
+
+ static struct g { int a; char buf[n]; } *p; (void)p;
+ { static struct g { int a; char buf[3]; } *p; (void)p; }
+
+ static struct h { int a; void (*s)(char buf[n]); } *t; (void)t;
+ { static struct h { int a; void (*s)(char buf[3]); } *t; (void)t; }
+}
+
+
+
diff --git a/gcc/testsuite/gcc.dg/c2x-tag-composite-2.c
b/gcc/testsuite/gcc.dg/c2x-tag-composite-2.c
new file mode 100644
index 00000000000..dfc4336751a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-tag-composite-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c2x" } */
+
+
+struct foo { int (*(*i)(void))[]; } x;
+
+
+void f(void)
+{
+ const struct foo { int (*(*i)())[3]; } y;
+ _Static_assert(3 * sizeof(int) == sizeof(*((1 ? &x : &y)->i())), "");
+}
+
+void g(struct foo { int x; } a);
+void g(const struct foo { int x; } a);
+
diff --git a/gcc/testsuite/gcc.dg/c2x-tag-composite-3.c
b/gcc/testsuite/gcc.dg/c2x-tag-composite-3.c
new file mode 100644
index 00000000000..02159f3c44d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-tag-composite-3.c
@@ -0,0 +1,17 @@
+/* { dg-do compile }
+ * { dg-options "-std=c2x" }
+ */
+
+// bit-fields
+
+extern struct foo { int x:3; } x;
+struct foo { int x:3; } y;
+
+void f(void)
+{
+ extern typeof(*(1 ? &x : &y)) x;
+ &x.x; /* { dg-error "bit-field" } */
+}
+
+struct foo { int x:2; }; /* { dg-error "redefinition" }
*/
+
diff --git a/gcc/testsuite/gcc.dg/c2x-tag-composite-4.c
b/gcc/testsuite/gcc.dg/c2x-tag-composite-4.c
new file mode 100644
index 00000000000..1bd98cc1a44
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-tag-composite-4.c
@@ -0,0 +1,21 @@
+/* { dg-do compile }
+ * { dg-options "-std=c2x" }
+ */
+
+// conditional operator
+
+void f(void)
+{
+ struct foo { int x; } a;
+ struct foo { int x; } b;
+ 1 ? a : b;
+}
+
+struct bar { int x; } a;
+
+void g(void)
+{
+ struct bar { int x; } b;
+ 1 ? a : b;
+}
+
--
2.30.2
[C PATCH 6/6] c23: construct composite type for tagged types
Martin Uecker via Gcc-patches Sat, 26 Aug 2023 09:26:26 -0700
- c23 type compatibility rules, v2 Martin Uecker via Gcc-patches
- [C PATCH 1/6] c: reorganize recursive ... Martin Uecker via Gcc-patches
- Re: [C PATCH 1/6] c: reorganize re... Joseph Myers
- [C PATCH 1/6 v2] c: reorganize... Martin Uecker via Gcc-patches
- Re: [C PATCH 1/6 v2] c: re... Joseph Myers
- [C PATCH 2/6] c23: recursive type check... Martin Uecker via Gcc-patches
- [C PATCH 3/6] c23: tag compatibility ru... Martin Uecker via Gcc-patches
- [C PATCH 4/6] c23: tag compatibility ru... Martin Uecker via Gcc-patches
- [C PATCH 5/6] c23: aliasing of compatib... Martin Uecker via Gcc-patches
- [C PATCH 6/6] c23: construct composite ... Martin Uecker via Gcc-patches
- [C PATCH] c: flag for tag compatibility... Martin Uecker via Gcc-patches
