Bit-fields need additional checks for type compatiblity.
Bootstrapped and regression tested on x86_64.
c: correct type compatibility for bit-fields [PR117828]
Add missing test for consistency of bit-fields when comparing tagged
types for compatibility.
PR c/117828
gcc/c/ChangeLog:
* c-typeck.c (tagged_types_tu_compatible_p): Add check.
gcc/testsuite/ChangeLog:
* c23-tag-bitfields-1.c: New test.
* pr117828.c: New test.
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 23ce0fc788d..dd13f212cd5 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -1909,18 +1909,33 @@ tagged_types_tu_compatible_p (const_tree t1, const_tree
t2,
gcc_assert (TREE_CODE (s1) == FIELD_DECL);
gcc_assert (TREE_CODE (s2) == FIELD_DECL);
+ tree ft1 = TREE_TYPE (s1);
+ tree ft2 = TREE_TYPE (s2);
+
if (DECL_NAME (s1) != DECL_NAME (s2))
return false;
if (DECL_ALIGN (s1) != DECL_ALIGN (s2))
return false;
+ if (DECL_C_BIT_FIELD (s1) != DECL_C_BIT_FIELD (s2))
+ return false;
+
+ if (DECL_C_BIT_FIELD (s1))
+ {
+ if (!tree_int_cst_equal (DECL_SIZE (s1), DECL_SIZE (s2)))
+ return false;
+
+ ft1 = DECL_BIT_FIELD_TYPE (s1);
+ ft2 = DECL_BIT_FIELD_TYPE (s2);
+ }
+
data->anon_field = !DECL_NAME (s1);
data->pointedto = false;
const struct tagged_tu_seen_cache *cache = data->cache;
data->cache = &entry;
- bool ret = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2),
data);
+ bool ret = comptypes_internal (ft1, ft2, data);
data->cache = cache;
if (!ret)
return false;
diff --git a/gcc/testsuite/gcc.dg/c23-tag-bitfields-1.c
b/gcc/testsuite/gcc.dg/c23-tag-bitfields-1.c
new file mode 100644
index 00000000000..d775d9f67a1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-tag-bitfields-1.c
@@ -0,0 +1,51 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c23" } */
+
+struct bar0 { int r : 16; };
+struct bar0 { int r : 16; };
+
+struct bar1 { int r : 16; };
+struct bar1 { int r : 17; }; /* { dg-error "redefinition" }
*/
+
+extern struct { int r : 14; } a;
+extern struct { int r : 14; } b;
+
+extern struct { int r : 14; } x;
+extern struct { int r : 13; } x; /* { dg-error "conflicting" } */
+
+struct bar2 { int s; int: 0; };
+struct bar2 { int s; int: 15; }; /* { dg-error "redefinition" }
*/
+
+struct bar3 { int s; int : 0; };
+struct bar3 { int s; }; /* { dg-error
"redefinition" } */
+
+struct bar4 { int r : 3; };
+struct bar4 { const int r : 3; }; /* { dg-error "redefinition" }
*/
+
+struct bar5 { int r : 16; };
+struct bar5 { int r; }; /* { dg-error
"redefinition" } */
+
+union ubar { int r : 16; };
+union ubar { int r : 16; };
+
+union ubar1 { int r : 16; };
+union ubar1 { int r : 17; }; /* { dg-error "redefinition" }
*/
+
+extern union { int r : 14; } c;
+extern union { int r : 14; } d;
+
+extern union { int r : 14; } y;
+extern union { int r : 13; } y; /* { dg-error
"conflicting" } */
+
+union ubar2 { int s; int : 0; };
+union ubar2 { int s; int : 15; }; /* { dg-error "redefinition" }
*/
+
+union ubar3 { int s: 3; int: 0; };
+union ubar3 { int s: 3; }; /* { dg-error "redefinition" }
*/
+
+union ubar4 { int r : 3; };
+union ubar4 { const int r : 3; }; /* { dg-error "redefinition" }
*/
+
+union ubar5 { int r : 16; };
+union ubar5 { int r; }; /* { dg-error
"redefinition" } */
+
diff --git a/gcc/testsuite/gcc.dg/pr117828.c b/gcc/testsuite/gcc.dg/pr117828.c
new file mode 100644
index 00000000000..a219f8e51a2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr117828.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-g" } */
+
+struct {
+ struct {
+ int Reserved : 32;
+ } u;
+} v;
+struct {
+ struct {
+ int Reserved;
+ } u;
+} w;
+
+
