[C PATCH] Fix ICE with -g and -std=c23 related to incomplete types [PR114361]

[Martin Uecker <uecker@tugraz.at>]

I did not copy TYPE_CANONICAL to incomplete variants
when they are completed.



Bootstrapped and regession tested on x86_64



Fix ICE with -g and -std=c23 related to incomplete types [PR114361]

We did not copy TYPE_CANONICAL to the incomplete variants when
completing a structure.

            PR c/114361

    gcc/c/
            * c-decl.c (finish_struct): Set TYPE_CANONICAL when completing
	    strucute types.

    gcc/testsuite/
            * gcc.dg/pr114361.c: New test.
            * gcc.dg/c23-tag-incomplete-1.c: New test.
            * gcc.dg/c23-tag-incomplete-2.c: New test.
---
 gcc/c/c-decl.cc                             |  1 +
 gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c | 14 ++++++++++++++
 gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c | 13 +++++++++++++
 gcc/testsuite/gcc.dg/pr114361.c             | 11 +++++++++++
 4 files changed, 39 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c
 create mode 100644 gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c
 create mode 100644 gcc/testsuite/gcc.dg/pr114361.c

diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index c747abe9f4e..f2083b9d96f 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -9722,6 +9722,7 @@ finish_struct (location_t loc, tree t, tree fieldlist, tree attributes,
       C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t);
       C_TYPE_VARIABLY_MODIFIED (x) = C_TYPE_VARIABLY_MODIFIED (t);
       C_TYPE_INCOMPLETE_VARS (x) = NULL_TREE;
+      TYPE_CANONICAL (x) = TYPE_CANONICAL (t);
     }
 
   /* Update type location to the one of the definition, instead of e.g.
diff --git a/gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c b/gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c
new file mode 100644
index 00000000000..82d652569e9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-tag-incomplete-1.c
@@ -0,0 +1,14 @@
+/* { dg-do compile }
+ * { dg-options "-std=c23 -g" } */
+
+struct a;
+typedef struct a b;
+
+void g() {
+    struct a { b* x; };
+}
+
+struct a { b* x; };
+
+
+
diff --git a/gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c b/gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c
new file mode 100644
index 00000000000..bc47a04ece5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-tag-incomplete-2.c
@@ -0,0 +1,13 @@
+/* { dg-do compile }
+ * { dg-options "-std=c23 -g" } */
+
+struct a;
+typedef struct a b;
+
+void f() {
+	extern struct a { b* x; } t;
+}
+
+extern struct a { b* x; } t;
+
+
diff --git a/gcc/testsuite/gcc.dg/pr114361.c b/gcc/testsuite/gcc.dg/pr114361.c
new file mode 100644
index 00000000000..0f3feb53566
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr114361.c
@@ -0,0 +1,11 @@
+/* PR c/114361 */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu23 -g" } */
+
+void f()
+{
+    typedef struct foo bar;
+    typedef __typeof( ({ (struct foo { bar *x; }){ }; }) ) wuz;
+    struct foo { wuz *x; };
+}
+
-- 
2.39.2