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| author | Aaron Crane <arc@cpan.org> | 2017-10-12 13:47:22 +0200 |
|---|---|---|
| committer | Aaron Crane <arc@cpan.org> | 2017-10-21 16:51:21 +0100 |
| commit | 1c1d7d5ba0bc33e7bea0a9aeb2d420fc5a8128ab (patch) | |
| tree | 74492a42f48126a77646de9420baebc6c28041bf /uconfig.h | |
| parent | 04322328fc4bc2863d0bc74339ed92d33b7eaba7 (diff) | |
| download | perl-1c1d7d5ba0bc33e7bea0a9aeb2d420fc5a8128ab.tar.gz | |
Don't look for a "safe" memcpy()
C89 says that, if you want to copy overlapping memory blocks, you must use
memmove(), and that attempt to copy overlapping memory blocks using memcpy()
yields undefined behaviour. So we should never even attempt to probe for a
system memcpy() implementation that just happens to handle overlapping
memory blocks. In particular, the compiler might compile the probe program
in such a way that Configure thinks overlapping memcpy() works even when it
doesn't.
This has the additional advantage of removing a Configure probe that needs
to execute a target-platform program on the build host.
Diffstat (limited to 'uconfig.h')
| -rw-r--r-- | uconfig.h | 12 |
1 files changed, 2 insertions, 10 deletions
@@ -1084,14 +1084,6 @@ */ /*#define HAS_SAFE_BCOPY / **/ -/* HAS_SAFE_MEMCPY: - * This symbol, if defined, indicates that the memcpy routine is available - * to copy potentially overlapping memory blocks. If you need to - * copy overlapping memory blocks, you should check HAS_MEMMOVE and - * use memmove() instead, if available. - */ -/*#define HAS_SAFE_MEMCPY / **/ - /* HAS_SANE_MEMCMP: * This symbol, if defined, indicates that the memcmp routine is available * and can be used to compare relative magnitudes of chars with their high @@ -5427,6 +5419,6 @@ #endif /* Generated from: - * 7ff89cdb1fe8ce0204ce7e895ef3799d115d4e499f4b93f639ab96b64a63d57e config_h.SH - * bd4d12ab7495a044625abc3e1128f6939bdb50a02a59ae3a1b8bf64433002191 uconfig.sh + * d9687e4eb62ebccd02be4a08612dc1bcfd95119f0008203aee08f29c997ebfc3 config_h.SH + * 4fb77492d82d8e37400b5d34c71f1c2489d5dc04e82e61ec78998af0fdd60d99 uconfig.sh * ex: set ro: */ |