https://gcc.gnu.org/g:7825c07bbaf503c47ecedd87e3d64be003b24f2c
commit r15-1929-g7825c07bbaf503c47ecedd87e3d64be003b24f2c
Author: Martin Uecker <uec...@tugraz.at>
Date: Sat Jun 29 15:53:43 2024 +0200
c: Fix ICE for redeclaration of structs with different alignment [PR114727]
For redeclarations of struct in C23, if one has an alignment attribute
that makes the alignment different, we later get an ICE in verify_types.
This patches disallows such redeclarations by declaring such types to
be different.
PR c/114727
gcc/c/
* c-typeck.cc (tagged_types_tu_compatible): Add test.
gcc/testsuite/
* gcc.dg/pr114727.c: New test.
Diff:
---
gcc/c/c-typeck.cc | 3 +++
gcc/testsuite/gcc.dg/pr114727.c | 6 ++++++
2 files changed, 9 insertions(+)
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index e486ac04f9cf..455dc374b481 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -1603,6 +1603,9 @@ tagged_types_tu_compatible_p (const_tree t1, const_tree
t2,
!= TYPE_REVERSE_STORAGE_ORDER (t2)))
return false;
+ if (TYPE_USER_ALIGN (t1) != TYPE_USER_ALIGN (t2))
+ data->different_types_p = true;
+
/* For types already being looked at in some active
invocation of this function, assume compatibility.
The cache is built as a linked list on the stack
diff --git a/gcc/testsuite/gcc.dg/pr114727.c b/gcc/testsuite/gcc.dg/pr114727.c
new file mode 100644
index 000000000000..12949590ce09
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr114727.c
@@ -0,0 +1,6 @@
+/* { dg-do compile }
+ * { dg-options "-std=c23 -g" } */
+
+#define Y [[gnu::aligned(128)]]
+extern struct Y foo { int x; } x;
+struct foo { int x; }; /* { dg-error "redefinition" } */
