From: Martin Uecker <uecker@tugraz.at>
To: gcc-patches@gcc.gnu.org
Cc: Joseph Myers <joseph@codesourcery.com>
Subject: [C PATCH] c: flag for tag compatibility rules
Date: Sat, 26 Aug 2023 18:26:55 +0200 [thread overview]
Message-ID: <157a7b1266c6d3b46b2be59f878d8469abdd21bc.camel@tugraz.at> (raw)
In-Reply-To: <4b3866a8cc9b48f3be97c004dedbac8e9149da63.camel@tugraz.at>
Add a flag to turn tag compatibility rules on or off
independent from the language version.
gcc/c-family:
* c.opt (flag_tag_compat): New flag.
gcc/c:
* c-decl.cc (diagnose_mismatched_decls, start_struct,
finish_struct, start_enum, finish_enum): Support flag.
* c-typeck.cc (composite_type_internal): Support flag.
gcc/doc:
* invoke.texi: Document flag.
gcc/testsuite:
* gcc.dg/asan/pr81470.c: Turn off tag compatibility.
* gcc.dg/c99-tag-1.c: Turn off tag compatibility.
* gcc.dg/c99-tag-2.c: Turn off tag compatibility.
* gcc.dg/decl-3.c: Turn off tag compatibility.
* gcc.dg/enum-redef-1.c: Turn off tag compatibility.
* gcc.dg/pr17188-1.c: Turn off tag compatibility.
* gcc.dg/pr18809-1.c: Turn off tag compatibility.
* gcc.dg/pr39084.c: Turn off tag compatibility.
* gcc.dg/pr79983.c: Turn off tag compatibility.
---
gcc/c-family/c.opt | 3 +++
gcc/c/c-decl.cc | 12 ++++++------
gcc/c/c-typeck.cc | 2 +-
gcc/doc/invoke.texi | 5 +++++
gcc/testsuite/gcc.dg/asan/pr81460.c | 1 +
gcc/testsuite/gcc.dg/c99-tag-1.c | 2 +-
gcc/testsuite/gcc.dg/c99-tag-2.c | 2 +-
gcc/testsuite/gcc.dg/decl-3.c | 1 +
gcc/testsuite/gcc.dg/enum-redef-1.c | 2 ++
gcc/testsuite/gcc.dg/pr17188-1.c | 2 +-
gcc/testsuite/gcc.dg/pr18809-1.c | 1 +
gcc/testsuite/gcc.dg/pr39084.c | 2 +-
gcc/testsuite/gcc.dg/pr79983.c | 2 +-
13 files changed, 25 insertions(+), 12 deletions(-)
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 2242524cd3e..f95f12ba249 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -2214,6 +2214,9 @@ Enum(strong_eval_order) String(some) Value(1)
EnumValue
Enum(strong_eval_order) String(all) Value(2)
+ftag-compat
+C Var(flag_tag_compat) Init(1)
+
ftemplate-backtrace-limit=
C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
Set the maximum number of template instantiation notes for a single warning or error.
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 2137ba8b845..6d1e0d5c382 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -2094,7 +2094,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
given scope. */
if (TREE_CODE (olddecl) == CONST_DECL)
{
- if (flag_isoc2x
+ if ((flag_isoc2x || flag_tag_compat)
&& TYPE_NAME (DECL_CONTEXT (newdecl))
&& DECL_CONTEXT (newdecl) != DECL_CONTEXT (olddecl)
&& TYPE_NAME (DECL_CONTEXT (newdecl)) == TYPE_NAME (DECL_CONTEXT (olddecl)))
@@ -8723,7 +8723,7 @@ start_struct (location_t loc, enum tree_code code, tree name,
/* For C2X, even if we already have a completed definition,
we do not use it. We will check for consistency later. */
- if (flag_isoc2x && ref && TYPE_SIZE (ref))
+ if ((flag_isoc2x || flag_tag_compat) && ref && TYPE_SIZE (ref))
ref = NULL_TREE;
if (ref && TREE_CODE (ref) == code)
@@ -9515,7 +9515,7 @@ finish_struct (location_t loc, tree t, tree fieldlist, tree attributes,
}
/* Check for consistency with previous definition */
- if (flag_isoc2x)
+ if (flag_isoc2x || flag_tag_compat)
{
tree vistype = previous_tag (t);
if (vistype
@@ -9534,7 +9534,7 @@ finish_struct (location_t loc, tree t, tree fieldlist, tree attributes,
C_TYPE_BEING_DEFINED (t) = 0;
/* Set type canonical based on equivalence class. */
- if (flag_isoc2x)
+ if (flag_isoc2x || flag_tag_compat)
{
if (NULL == c_struct_htab)
c_struct_htab = hash_table<c_struct_hasher>::create_ggc (61);
@@ -9672,7 +9672,7 @@ start_enum (location_t loc, struct c_enum_contents *the_enum, tree name,
if (name != NULL_TREE)
enumtype = lookup_tag (ENUMERAL_TYPE, name, true, &enumloc);
- if (flag_isoc2x && enumtype != NULL_TREE
+ if ((flag_isoc2x || flag_tag_compat) && enumtype != NULL_TREE
&& TREE_CODE (enumtype) == ENUMERAL_TYPE
&& TYPE_VALUES (enumtype) != NULL_TREE)
enumtype = NULL_TREE;
@@ -9941,7 +9941,7 @@ finish_enum (tree enumtype, tree values, tree attributes)
struct_parse_info->struct_types.safe_push (enumtype);
/* Check for consistency with previous definition */
- if (flag_isoc2x)
+ if (flag_isoc2x || flag_tag_compat)
{
tree vistype = previous_tag (enumtype);
if (vistype
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 357367eab09..b99f0c3e2fd 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -512,7 +512,7 @@ composite_type_internal (tree t1, tree t2, struct composite_cache* cache)
case RECORD_TYPE:
case UNION_TYPE:
- if (flag_isoc2x && !comptypes_same_p (t1, t2))
+ if ((flag_isoc2x || flag_tag_compat) && !comptypes_same_p (t1, t2))
{
gcc_checking_assert (COMPLETE_TYPE_P (t1) && COMPLETE_TYPE_P (t2));
gcc_checking_assert (comptypes (t1, t2));
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index a32dabf0405..d7a21ca8678 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -2911,6 +2911,11 @@ the target (the default). This option is not supported for C++.
@strong{Warning:} the @option{-fsso-struct} switch causes GCC to generate
code that is not binary compatible with code generated without it if the
specified endianness is not the native endianness of the target.
+
+@item -ftag-compat
+@opindex ftag-compat
+This option makes tagged types that are structurally equivalent compatible
+and allows identical redeclarations of tagged types in the same scope.
@end table
@node C++ Dialect Options
diff --git a/gcc/testsuite/gcc.dg/asan/pr81460.c b/gcc/testsuite/gcc.dg/asan/pr81460.c
index 00c1bb7c9f2..98ea40edb56 100644
--- a/gcc/testsuite/gcc.dg/asan/pr81460.c
+++ b/gcc/testsuite/gcc.dg/asan/pr81460.c
@@ -1,5 +1,6 @@
/* PR sanitizer/80460 */
/* { dg-do compile } */
+/* { dg-options "-fno-tag-compat" } */
int
f (int a, struct { int b[a]; } c) /* { dg-warning "anonymous struct declared inside parameter list will not be visible outside of this definition or declaration" } */
diff --git a/gcc/testsuite/gcc.dg/c99-tag-1.c b/gcc/testsuite/gcc.dg/c99-tag-1.c
index d7011d2cbec..1b52234ee3f 100644
--- a/gcc/testsuite/gcc.dg/c99-tag-1.c
+++ b/gcc/testsuite/gcc.dg/c99-tag-1.c
@@ -1,7 +1,7 @@
/* Test for handling of tags (6.7.2.3). */
/* Origin: Joseph Myers <jsm28@cam.ac.uk> */
/* { dg-do compile } */
-/* { dg-options "-std=iso9899:1999 -pedantic-errors" } */
+/* { dg-options "-std=iso9899:1999 -pedantic-errors -fno-tag-compat" } */
void
foo (void)
diff --git a/gcc/testsuite/gcc.dg/c99-tag-2.c b/gcc/testsuite/gcc.dg/c99-tag-2.c
index 22cf90e27d3..b12c7bcd964 100644
--- a/gcc/testsuite/gcc.dg/c99-tag-2.c
+++ b/gcc/testsuite/gcc.dg/c99-tag-2.c
@@ -2,7 +2,7 @@
not match one declared in an outer scope. */
/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
/* { dg-do compile } */
-/* { dg-options "-std=iso9899:1999 -pedantic-errors" } */
+/* { dg-options "-std=iso9899:1999 -pedantic-errors -fno-tag-compat" } */
struct s;
struct t { struct s *p; } x;
diff --git a/gcc/testsuite/gcc.dg/decl-3.c b/gcc/testsuite/gcc.dg/decl-3.c
index cba0b906db3..66204270337 100644
--- a/gcc/testsuite/gcc.dg/decl-3.c
+++ b/gcc/testsuite/gcc.dg/decl-3.c
@@ -1,5 +1,6 @@
/* PR c/9928 */
/* { dg-do compile } */
+/* { dg-options "-fno-tag-compat" } */
enum { CODES }; /* { dg-message "note: previous definition" } */
enum { CODES }; /* { dg-error "conflicting types|redeclaration of enumerator" } */
diff --git a/gcc/testsuite/gcc.dg/enum-redef-1.c b/gcc/testsuite/gcc.dg/enum-redef-1.c
index b3fa6cbf8f1..837992f7441 100644
--- a/gcc/testsuite/gcc.dg/enum-redef-1.c
+++ b/gcc/testsuite/gcc.dg/enum-redef-1.c
@@ -1,3 +1,5 @@
+/* { dg-options "-fno-tag-compat" } */
+
enum a { A };
enum a { B }; /* { dg-bogus "nested redefinition" } */
/* { dg-error "redeclaration of 'enum a'" "" { target *-*-* } .-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr17188-1.c b/gcc/testsuite/gcc.dg/pr17188-1.c
index 522a14f7d75..bb31ba30b5d 100644
--- a/gcc/testsuite/gcc.dg/pr17188-1.c
+++ b/gcc/testsuite/gcc.dg/pr17188-1.c
@@ -3,7 +3,7 @@
diagnosed. Bug 17188. */
/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
/* { dg-do compile } */
-/* { dg-options "" } */
+/* { dg-options "-fno-tag-compat" } */
struct s0 { }; /* { dg-message "note: originally defined here" } */
struct s0;
diff --git a/gcc/testsuite/gcc.dg/pr18809-1.c b/gcc/testsuite/gcc.dg/pr18809-1.c
index 5be41809da6..d7f55feae61 100644
--- a/gcc/testsuite/gcc.dg/pr18809-1.c
+++ b/gcc/testsuite/gcc.dg/pr18809-1.c
@@ -1,6 +1,7 @@
/* PR c/18809 */
/* Origin: Andrew Pinski <pinskia@gcc.gnu.org> */
+/* { dg-options "-pedantic-errors -fno-tag-compat" } */
/* { dg-do compile } */
void foo(enum E e) {} /* { dg-error "forward ref" "forward" } */
diff --git a/gcc/testsuite/gcc.dg/pr39084.c b/gcc/testsuite/gcc.dg/pr39084.c
index ff731492154..776fbea6750 100644
--- a/gcc/testsuite/gcc.dg/pr39084.c
+++ b/gcc/testsuite/gcc.dg/pr39084.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -fno-tag-compat" } */
struct color { int i; }; /* { dg-message "note: originally defined here" } */
static const struct color col;
diff --git a/gcc/testsuite/gcc.dg/pr79983.c b/gcc/testsuite/gcc.dg/pr79983.c
index 1e292d42108..c9fe72f9169 100644
--- a/gcc/testsuite/gcc.dg/pr79983.c
+++ b/gcc/testsuite/gcc.dg/pr79983.c
@@ -1,6 +1,6 @@
/* PR c/79983 */
/* { dg-do compile } */
-/* { dg-options "" } */
+/* { dg-options "-fno-tag-compat" } */
struct S;
struct S { int i; }; /* { dg-message "originally defined here" } */
--
2.30.2
prev parent reply other threads:[~2023-08-26 16:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-26 16:19 c23 type compatibility rules, v2 Martin Uecker
2023-08-26 16:20 ` [C PATCH 1/6] c: reorganize recursive type checking Martin Uecker
2023-09-06 20:59 ` Joseph Myers
2023-09-10 8:17 ` [C PATCH 1/6 v2] " Martin Uecker
2023-09-11 20:28 ` Joseph Myers
2023-08-26 16:22 ` [C PATCH 2/6] c23: recursive type checking of tagged type Martin Uecker
2023-11-07 23:06 ` Joseph Myers
2023-08-26 16:23 ` [C PATCH 3/6] c23: tag compatibility rules for struct and unions Martin Uecker
2023-11-07 23:18 ` Joseph Myers
2023-08-26 16:24 ` [C PATCH 4/6] c23: tag compatibility rules for enums Martin Uecker
2023-11-07 23:20 ` Joseph Myers
2023-08-26 16:25 ` [C PATCH 5/6] c23: aliasing of compatible tagged types Martin Uecker
2023-08-26 16:26 ` [C PATCH 6/6] c23: construct composite type for " Martin Uecker
2023-11-07 23:45 ` Joseph Myers
2023-08-26 16:26 ` Martin Uecker [this message]
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