From: Patrick Palka <ppalka@redhat.com>
To: gcc-patches@gcc.gnu.org
Cc: libstdc++@gcc.gnu.org, jason@redhat.com,
Patrick Palka <ppalka@redhat.com>
Subject: [PATCH 1/2] c++: correct __has_attribute(init_priority)
Date: Fri, 4 Nov 2022 11:05:24 -0400 [thread overview]
Message-ID: <20221104150525.2968778-1-ppalka@redhat.com> (raw)
Currently __has_attribute(init_priority) always returns true, even on
targets that don't actually support init priorities, and when using
the attribute on such targets, we issue a hard error that init
priorities are unsupported. This makes it impossible to conditionally
use the attribute by querying __has_attribute.
This patch fixes this by adding the attribute to the attribute table
only if the target supports init priorities, so that __has_attribute
returns false appropriately. Thus on such targets we'll now treat it as
just another unrecognized attribute, so using it gives a -Wattribute
warning instead of an error.
gcc/cp/ChangeLog:
* tree.cc (cxx_attribute_table): Add entry for init_priority
only if SUPPORTS_INIT_PRIORITY.
(handle_init_priority_attribute): Assert SUPPORTS_INIT_PRIORITY
is true.
gcc/testsuite/ChangeLog:
* g++.dg/special/initpri3.C: New test.
---
gcc/cp/tree.cc | 20 +++++++-------------
gcc/testsuite/g++.dg/special/initpri3.C | 9 +++++++++
2 files changed, 16 insertions(+), 13 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/special/initpri3.C
diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index 45348c58bb6..c30bbeb0839 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -5010,8 +5010,10 @@ const struct attribute_spec cxx_attribute_table[] =
{
/* { name, min_len, max_len, decl_req, type_req, fn_type_req,
affects_type_identity, handler, exclude } */
+#if SUPPORTS_INIT_PRIORITY
{ "init_priority", 1, 1, true, false, false, false,
handle_init_priority_attribute, NULL },
+#endif
{ "abi_tag", 1, -1, false, false, false, true,
handle_abi_tag_attribute, NULL },
{ NULL, 0, 0, false, false, false, false, NULL, NULL }
@@ -5039,7 +5041,7 @@ const struct attribute_spec std_attribute_table[] =
/* Handle an "init_priority" attribute; arguments as in
struct attribute_spec.handler. */
-static tree
+ATTRIBUTE_UNUSED static tree
handle_init_priority_attribute (tree* node,
tree name,
tree args,
@@ -5103,18 +5105,10 @@ handle_init_priority_attribute (tree* node,
pri);
}
- if (SUPPORTS_INIT_PRIORITY)
- {
- SET_DECL_INIT_PRIORITY (decl, pri);
- DECL_HAS_INIT_PRIORITY_P (decl) = 1;
- return NULL_TREE;
- }
- else
- {
- error ("%qE attribute is not supported on this platform", name);
- *no_add_attrs = true;
- return NULL_TREE;
- }
+ gcc_assert (SUPPORTS_INIT_PRIORITY);
+ SET_DECL_INIT_PRIORITY (decl, pri);
+ DECL_HAS_INIT_PRIORITY_P (decl) = 1;
+ return NULL_TREE;
}
/* DECL is being redeclared; the old declaration had the abi tags in OLD,
diff --git a/gcc/testsuite/g++.dg/special/initpri3.C b/gcc/testsuite/g++.dg/special/initpri3.C
new file mode 100644
index 00000000000..a181abdd0b1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/special/initpri3.C
@@ -0,0 +1,9 @@
+// Verify __has_attribute(init_priority) is false whenever the platform
+// doesn't support it, and is treated as an unrecognized attribute.
+
+#if !__has_attribute(init_priority)
+#error init_priority /* { dg-error "" "" { target { ! init_priority } } } */
+#endif
+
+struct A { A(); } a __attribute__((init_priority(500)));
+// { dg-warning "attribute directive ignored" "" { target { ! init_priority } } .-1 }
--
2.38.1.385.g3b08839926
next reply other threads:[~2022-11-04 15:05 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-04 15:05 Patrick Palka [this message]
2022-11-04 15:05 ` [PATCH 2/2] libstdc++: Move stream initialization into compiled library [PR44952] Patrick Palka
2022-11-04 15:24 ` Jonathan Wakely
2022-11-04 16:31 ` Patrick Palka
2022-11-04 16:42 ` Jonathan Wakely
2022-11-04 16:57 ` Florian Weimer
2022-11-04 17:47 ` Patrick Palka
2022-11-04 18:16 ` Florian Weimer
2022-11-15 16:10 ` Hans-Peter Nilsson
2022-11-04 15:55 ` [PATCH 1/2] c++: correct __has_attribute(init_priority) Jason Merrill
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