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10bb9e6fab
* include/ruby/missing.h (explicit_bzero_by_memset_s): call memset_s directly if available. * missing/explicit_bzero.c: optimization is not a matter if memset_s is available. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52824 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
49 lines
890 B
C
49 lines
890 B
C
#include "ruby/missing.h"
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#include <string.h>
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/*
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*BSD have explicit_bzero().
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Windows, OS-X have memset_s().
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Linux has none. *Sigh*
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*/
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/*
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* Following URL explain why memset_s is added to the standard.
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* http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1381.pdf
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*/
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#ifndef FUNC_UNOPTIMIZED
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# define FUNC_UNOPTIMIZED(x) x
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#endif
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#ifndef HAVE_EXPLICIT_BZERO
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/* Similar to bzero(), but have a guarantee not to be eliminated from compiler
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optimization. */
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#ifndef HAVE_MEMSET_S
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FUNC_UNOPTIMIZED(void explicit_bzero(void *b, size_t len));
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#endif
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#undef explicit_bzero
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void
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explicit_bzero(void *b, size_t len)
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{
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#ifdef HAVE_MEMSET_S
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memset_s(b, len, 0, len);
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#else
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{
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/*
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* TODO: volatile is not enough if compiler have a LTO (link time
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* optimization)
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*/
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volatile char* p = (volatile char*)b;
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while(len) {
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*p = 0;
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p++;
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len--;
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}
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}
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#endif
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}
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#endif
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