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authorH.J. Lu <hongjiu.lu@intel.com>2016-02-18 11:00:33 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2016-02-18 14:55:29 -0200
commit16396c41deab45f715ffd813280d9d685b3b281e (patch)
tree5ed0830f0b3524559d6a099c3a19af14223ef28a /bits
parent6400ae6ecf6376af230d3ec82a8541848d3239e9 (diff)
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Add _STRING_INLINE_unaligned and string_private.h
As discussed in

https://sourceware.org/ml/libc-alpha/2015-10/msg00403.html

the setting of _STRING_ARCH_unaligned currently controls the external
GLIBC ABI as well as selecting the use of unaligned accesses withing
GLIBC.

Since _STRING_ARCH_unaligned was recently changed for AArch64, this
would potentially break the ABI in GLIBC 2.23, so split the uses and add
_STRING_INLINE_unaligned to select the string ABI. This setting must be
fixed for each target, while _STRING_ARCH_unaligned may be changed from
release to release.  _STRING_ARCH_unaligned is used unconditionally in
glibc.  But <bits/string.h>, which defines _STRING_ARCH_unaligned, isn't
included with -Os.  Since _STRING_ARCH_unaligned is internal to glibc and
may change between glibc releases, it should be made private to glibc.
_STRING_ARCH_unaligned should defined in the new string_private.h heade
file which is included unconditionally from internal <string.h> for glibc
build.

	[BZ #19462]
	* bits/string.h (_STRING_ARCH_unaligned): Renamed to ...
	(_STRING_INLINE_unaligned): This.
	* include/string.h: Include <string_private.h>.
	* string/bits/string2.h: Replace _STRING_ARCH_unaligned with
	_STRING_INLINE_unaligned.
	* sysdeps/aarch64/bits/string.h (_STRING_ARCH_unaligned): Removed.
	(_STRING_INLINE_unaligned): New.
	* sysdeps/aarch64/string_private.h: New file.
	* sysdeps/generic/string_private.h: Likewise.
	* sysdeps/m68k/m680x0/m68020/string_private.h: Likewise.
	* sysdeps/s390/string_private.h: Likewise.
	* sysdeps/x86/string_private.h: Likewise.
	* sysdeps/m68k/m680x0/m68020/bits/string.h
	(_STRING_ARCH_unaligned): Renamed to ...
	(_STRING_INLINE_unaligned): This.
	* sysdeps/s390/bits/string.h (_STRING_ARCH_unaligned): Renamed
	to ...
	(_STRING_INLINE_unaligned): This.
	* sysdeps/sparc/bits/string.h (_STRING_ARCH_unaligned): Renamed
	to ...
	(_STRING_INLINE_unaligned): This.
	* sysdeps/x86/bits/string.h (_STRING_ARCH_unaligned): Renamed
	to ...
	(_STRING_INLINE_unaligned): This.
Diffstat (limited to 'bits')
-rw-r--r--bits/string.h8
1 files changed, 6 insertions, 2 deletions
diff --git a/bits/string.h b/bits/string.h
index b88a6bc601..89c627c182 100644
--- a/bits/string.h
+++ b/bits/string.h
@@ -8,7 +8,11 @@
 #ifndef _BITS_STRING_H
 #define _BITS_STRING_H	1
 
-/* Define if architecture can access unaligned multi-byte variables.  */
-#define _STRING_ARCH_unaligned   0
+/* Define whether to use the unaligned string inline ABI.
+   The string inline functions are an external ABI, thus cannot be changed
+   after the first release of a new target (unlike _STRING_ARCH_unaligned
+   which may be changed from release to release).  Targets must support
+   unaligned accesses in hardware if either define is set to true.  */
+#define _STRING_INLINE_unaligned   0
 
 #endif /* bits/string.h */