From: Martin Uecker <uecker@tugraz.at>
To: gcc-patches@gcc.gnu.org
Cc: Joseph Myers <joseph@codesourcery.com>,
"Jiang, Haochen" <haochen.jiang@intel.com>
Subject: [C PATCH] C: Fix type compatibility for structs with variable sized fields.
Date: Wed, 27 Dec 2023 20:23:50 +0100 [thread overview]
Message-ID: <8ec71de2b1c42f2ed75a97cabced6561861791ab.camel@tugraz.at> (raw)
In-Reply-To: <02a9b94e4d653b6f1b9f89a1b62187f46e871738.camel@tugraz.at>
This patch hopefully fixes the test failure we see with gnu23-tag-4.c.
It does for me locally with -march=native (which otherwise reproduces
the problem).
Bootstrapped and regession tested on x86_64
C: Fix type compatibility for structs with variable sized fields.
This fixes the test gcc.dg/gnu23-tag-4.c introduced by commit 23fee88f
which fails for -march=... because the DECL_FIELD_BIT_OFFSET are set
inconsistently for types with and without variable-sized field. This
is fixed by testing for DECL_ALIGN instead. The code is further
simplified by removing some unnecessary conditions, i.e. anon_field is
set unconditionaly and all fields are assumed to be DECL_FIELDs.
gcc/c:
* c-typeck.c (tagged_types_tu_compatible_p): Revise.
gcc/testsuite:
* gcc.dg./c23-tag-9.c: New test.
---
gcc/c/c-typeck.cc | 19 ++++++++-----------
gcc/testsuite/gcc.dg/c23-tag-9.c | 8 ++++++++
2 files changed, 16 insertions(+), 11 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/c23-tag-9.c
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 2d9139d09d2..84ddda1ebab 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -1511,8 +1511,6 @@ tagged_types_tu_compatible_p (const_tree t1, const_tree t2,
if (!data->anon_field && TYPE_STUB_DECL (t1) != TYPE_STUB_DECL (t2))
data->different_types_p = true;
- data->anon_field = false;
-
/* Incomplete types are incompatible inside a TU. */
if (TYPE_SIZE (t1) == NULL || TYPE_SIZE (t2) == NULL)
return false;
@@ -1592,22 +1590,21 @@ tagged_types_tu_compatible_p (const_tree t1, const_tree t2,
s1 && s2;
s1 = DECL_CHAIN (s1), s2 = DECL_CHAIN (s2))
{
- if (TREE_CODE (s1) != TREE_CODE (s2)
- || DECL_NAME (s1) != DECL_NAME (s2))
+ gcc_assert (TREE_CODE (s1) == FIELD_DECL);
+ gcc_assert (TREE_CODE (s2) == FIELD_DECL);
+
+ if (DECL_NAME (s1) != DECL_NAME (s2))
+ return false;
+
+ if (DECL_ALIGN (s1) != DECL_ALIGN (s2))
return false;
- if (!DECL_NAME (s1) && RECORD_OR_UNION_TYPE_P (TREE_TYPE (s1)))
- data->anon_field = true;
+ data->anon_field = !DECL_NAME (s1);
data->cache = &entry;
if (!comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2), data))
return false;
- if (TREE_CODE (s1) == FIELD_DECL
- && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
- DECL_FIELD_BIT_OFFSET (s2)) != 1)
- return false;
-
tree st1 = TYPE_SIZE (TREE_TYPE (s1));
tree st2 = TYPE_SIZE (TREE_TYPE (s2));
diff --git a/gcc/testsuite/gcc.dg/c23-tag-9.c b/gcc/testsuite/gcc.dg/c23-tag-9.c
new file mode 100644
index 00000000000..1d32560ec23
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-tag-9.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c23" } */
+
+struct foo { int x; } x;
+struct foo { alignas(128) int x; } y; /* { dg-error "redefinition" } */
+static_assert(alignof(y) == 128);
+
+
--
2.39.2
next prev parent reply other threads:[~2023-12-27 19:24 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-16 21:36 c23 type compatibility rules, v3 Martin Uecker
2023-11-16 21:38 ` [PATCH 1/4] c23: tag compatibility rules for struct and unions Martin Uecker
2023-11-23 23:17 ` Joseph Myers
2023-11-16 21:38 ` [PATCH 2/4] c23: tag compatibility rules for enums Martin Uecker
2023-11-23 23:26 ` Joseph Myers
2023-11-16 21:39 ` [PATCH 3/4] c23: aliasing of compatible tagged types Martin Uecker
2023-11-23 23:47 ` Joseph Myers
2023-11-26 22:48 ` Martin Uecker
2023-11-27 7:46 ` Richard Biener
2023-11-28 1:00 ` Joseph Myers
2023-11-28 6:49 ` Martin Uecker
2023-11-28 10:47 ` Richard Biener
2023-11-28 11:51 ` Martin Uecker
2023-11-16 21:40 ` [PATCH 4/4] c23: construct composite type for " Martin Uecker
2023-11-27 13:16 ` [V4] [C PATCH 1/4] c23: tag compatibility rules for struct and unions Martin Uecker
2023-12-14 20:53 ` Joseph Myers
2023-11-27 13:16 ` [V4] [PATCH 2/4] c23: tag compatibility rules for enums Martin Uecker
2023-12-14 20:58 ` Joseph Myers
2023-11-27 13:16 ` [V4] [PATCH 3/4] c23: aliasing of compatible tagged types Martin Uecker
2023-12-14 21:10 ` Joseph Myers
2023-11-27 13:16 ` [V4] [PATCH 4/4] c23: construct composite type for " Martin Uecker
2023-12-17 17:41 ` [V5] [C PATCH 1/4] c23: tag compatibility rules for struct and unions Martin Uecker
2023-12-19 21:48 ` Joseph Myers
2023-12-17 17:42 ` [V5] [C PATCH 2/4] c23: tag compatibility rules for enums Martin Uecker
2023-12-19 21:50 ` Joseph Myers
2023-12-17 17:42 ` [V5] [C PATCH 3/4] c23: aliasing of compatible tagged types Martin Uecker
2023-12-19 22:02 ` Joseph Myers
2023-12-17 17:42 ` [V5] [C PATCH 4/4] c23: construct composite type for " Martin Uecker
2023-12-19 22:25 ` Joseph Myers
2023-12-21 21:47 ` [V6] " Martin Uecker
2023-12-22 16:27 ` Joseph Myers
2023-12-27 19:23 ` Martin Uecker [this message]
2023-12-29 15:57 ` [C PATCH] C: Fix type compatibility for structs with variable sized fields Joseph Myers
2024-01-27 16:10 ` Fix ICE with -g and -std=c23 when forming composite types [PR113438] Martin Uecker
2024-01-29 20:27 ` Joseph Myers
2024-04-02 18:54 ` [C PATCH] Fix ICE with -g and -std=c23 related to incomplete types [PR114361] Martin Uecker
2024-04-02 20:31 ` Joseph Myers
2024-04-02 19:02 ` [C PATCH] fix aliasing for structures/unions with incomplete types Martin Uecker
2024-04-02 20:42 ` Joseph Myers
2024-04-02 21:22 ` Martin Uecker
2024-04-03 15:33 ` Joseph Myers
2024-04-14 12:30 ` [C PATCH, v2] Fix ICE with -g and -std=c23 related to incomplete types [PR114361] Martin Uecker
2024-04-14 12:38 ` Martin Uecker
2024-04-15 6:55 ` Richard Biener
2024-04-15 7:38 ` Jakub Jelinek
2024-04-15 7:59 ` Jakub Jelinek
2024-04-15 8:02 ` Richard Biener
2024-04-15 8:05 ` Jakub Jelinek
2024-04-15 10:48 ` [PATCH] c, v3: " Jakub Jelinek
2024-04-15 11:33 ` Richard Biener
2024-04-16 7:20 ` Jakub Jelinek
2024-04-19 20:39 ` Joseph Myers
2024-04-15 7:03 ` [C PATCH, v2] " Jakub Jelinek
2024-05-18 13:27 ` [C PATCH] Fix for some variably modified types not being recognized [PR114831] Martin Uecker
2024-05-18 13:29 ` Martin Uecker
2024-05-20 21:18 ` Joseph Myers
2024-05-18 20:18 ` [C PATCH] Fix for redeclared enumerator initialized with different type [PR115109] Martin Uecker
2024-05-19 10:24 ` [C PATCH, v2] " Martin Uecker
2024-05-20 21:30 ` Joseph Myers
2024-05-21 5:40 ` Martin Uecker
2024-05-23 20:51 ` Joseph Myers
2024-05-21 12:18 ` [C PATCH]: allow aliasing of compatible types derived from enumeral types [PR115157] Martin Uecker
2024-05-23 20:59 ` Joseph Myers
2024-05-23 21:30 ` Ian Lance Taylor
2024-05-23 21:47 ` Martin Uecker
2024-05-23 21:53 ` Ian Lance Taylor
2024-05-24 5:56 ` Richard Biener
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