With new compiler (gcc >= 9 ?) building uClibc-ng now gives this sort of warnings:
./include/libc-symbols.h:426:25: warning: '__EI_localeconv' specifies less restrictive attribute than its target 'localeconv': 'nothrow' [-Wmissing-attributes]
426 | extern __typeof (name) __EI_##name __attribute__((alias (__hidden_asmname1 (,#local))))
| ^~~~~
./include/libc-symbols.h:429:29: note: in expansion of macro '__hidden_ver1'
429 | # define hidden_def(name) __hidden_ver1(__GI_##name, name, name);
| ^~~~~~~~~~~~~
./include/libc-symbols.h:497:32: note: in expansion of macro 'hidden_def'
497 | # define libc_hidden_def(name) hidden_def (name)
| ^~~~~~~~~~
libc/misc/locale/locale.c:306:1: note: in expansion of macro 'libc_hidden_def'
306 | libc_hidden_def(localeconv)
| ^~~~~~~~~~~~~~~
In file included from libc/misc/locale/localeconv.c:8:
libc/misc/locale/locale.c:261:15: note: '__EI_localeconv' target declared here
261 | struct lconv *localeconv(void)
| ^~~~~~~~~~
The fix is mostly being backported/adapted from glibc.
---
include/libc-symbols.h | 14 ++++++++++----
include/sys/cdefs.h | 11 +++++++++++
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index 4dc05c76e..2254375ad 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -156,6 +156,11 @@
# define ASM_LINE_SEP ;
#endif
+#ifndef __attribute_copy__
+/* Provide an empty definition when cdefs.h is not included. */
+# define __attribute_copy__(arg)
+#endif
+
#ifndef __ASSEMBLER__
/* GCC understands weak symbols and aliases; use its interface where
possible, instead of embedded assembly language. */
@@ -163,13 +168,13 @@
/* Define ALIASNAME as a strong alias for NAME. */
# define strong_alias(name, aliasname) _strong_alias(name, aliasname)
# define _strong_alias(name, aliasname) \
- extern __typeof (name) aliasname __attribute__ ((alias (#name)));
+ extern __typeof (name) aliasname __attribute__ ((alias (#name))) __attribute_copy__ (name);
/* Same, but does not check for type match. Use sparingly.
Example: strong_alias(stat,stat64) may fail, this one works: */
# define strong_alias_untyped(name, aliasname) \
_strong_alias_untyped(name, aliasname)
# define _strong_alias_untyped(name, aliasname) \
- extern __typeof (aliasname) aliasname __attribute__ ((alias (#name)));
+ extern __typeof (aliasname) aliasname __attribute__ ((alias (#name))) __attribute_copy__ (name);
# ifdef HAVE_WEAK_SYMBOLS
@@ -182,7 +187,7 @@
If weak aliases are not available, this defines a strong alias. */
# define weak_alias(name, aliasname) _weak_alias (name, aliasname)
# define _weak_alias(name, aliasname) \
- extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
+ extern __typeof (name) aliasname __attribute__ ((weak, alias (#name))) __attribute_copy__ (name);
/* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */
# define weak_extern(symbol) _weak_extern (weak symbol)
@@ -423,7 +428,8 @@ FIXME! - ?
# define __hidden_asmname2(prefix, name) #prefix name
# define __hidden_ver1(local, internal, name) \
extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
- extern __typeof (name) __EI_##name __attribute__((alias (__hidden_asmname1 (,#local))))
+ extern __typeof (name) __EI_##name __attribute__((alias (__hidden_asmname1 (,#local)))) \
+ __attribute_copy__ (name)
# define hidden_ver(local, name) __hidden_ver1(local, __GI_##name, name);
# define hidden_data_ver(local, name) hidden_ver(local, name)
# define hidden_def(name) __hidden_ver1(__GI_##name, name, name);
diff --git a/include/sys/cdefs.h b/include/sys/cdefs.h
index a4359a05c..5c4daebcd 100644
--- a/include/sys/cdefs.h
+++ b/include/sys/cdefs.h
@@ -330,6 +330,17 @@
# endif
#endif
+/* Undefine (also defined in libc-symbols.h). */
+#undef __attribute_copy__
+#if __GNUC_PREREQ (9, 0)
+/* Copies attributes from the declaration or type referenced by
+ the argument. */
+# define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
+#else
+# define __attribute_copy__(arg)
+#endif
+
+
/* GCC 4.3 and above allow passing all anonymous arguments of an
__extern_always_inline function to some other vararg function. */
#if __GNUC_PREREQ (4,3)
--
2.17.1
