The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=a98e5d78500193dc7aa352e1f60ac2c6529e2c38
commit a98e5d78500193dc7aa352e1f60ac2c6529e2c38 Author: Konstantin Belousov <[email protected]> AuthorDate: 2025-12-03 23:56:26 +0000 Commit: Konstantin Belousov <[email protected]> CommitDate: 2025-12-08 22:34:57 +0000 libc/string: add strdupa(3) and strndupa(3) Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D54066 --- include/string.h | 28 ++++++++++++++++++++++++++++ lib/libc/string/Makefile.inc | 4 +++- lib/libc/string/strdup.3 | 34 +++++++++++++++++++++++++++++++++- 3 files changed, 64 insertions(+), 2 deletions(-) diff --git a/include/string.h b/include/string.h index a3fa96ebb449..e9aa1b55281a 100644 --- a/include/string.h +++ b/include/string.h @@ -154,6 +154,34 @@ void swab(const void * __restrict, void * __restrict, ssize_t); int timingsafe_bcmp(const void *, const void *, size_t); int timingsafe_memcmp(const void *, const void *, size_t); + +#if __has_builtin(__builtin_alloca) +#define strdupa(_Str) (__extension__({ \ + const char *_Str1; \ + size_t _Len; \ + char *_Copy; \ + \ + _Str1 = (_Str); \ + _Len = strlen(_Str1) + 1; \ + _Copy = (char *)__builtin_alloca(_Len); \ + memcpy(_Copy, _Str1, _Len); \ + _Copy; \ +})) + +#define strndupa(_Str, _Maxlen) (__extension__({ \ + const char *_Str1; \ + char *_Copy; \ + size_t _Len; \ + \ + _Str1 = (_Str); \ + _Len = strnlen((_Str1), (_Maxlen)); \ + _Copy = __builtin_alloca(_Len + 1); \ + (void)memcpy(_Copy, _Str1, _Len); \ + _Copy[_Len] = '\0'; \ + _Copy; \ +})) +#endif + #endif /* __BSD_VISIBLE */ #if __POSIX_VISIBLE >= 200112 || defined(_XLOCALE_H_) diff --git a/lib/libc/string/Makefile.inc b/lib/libc/string/Makefile.inc index 13cff22b9a32..dfe4b4b55bec 100644 --- a/lib/libc/string/Makefile.inc +++ b/lib/libc/string/Makefile.inc @@ -174,7 +174,9 @@ MLINKS+=strcoll.3 strcoll_l.3 MLINKS+=strcpy.3 stpcpy.3 \ strcpy.3 stpncpy.3 \ strcpy.3 strncpy.3 -MLINKS+=strdup.3 strndup.3 +MLINKS+=strdup.3 strndup.3 \ + strdup.3 strdupa.3 \ + strdup.3 strndupa.3 MLINKS+=strerror.3 perror.3 \ strerror.3 strerror_l.3 \ strerror.3 strerror_r.3 \ diff --git a/lib/libc/string/strdup.3 b/lib/libc/string/strdup.3 index 576fa122b8d6..5968289f5002 100644 --- a/lib/libc/string/strdup.3 +++ b/lib/libc/string/strdup.3 @@ -30,7 +30,9 @@ .Os .Sh NAME .Nm strdup , -.Nm strndup +.Nm strdupa , +.Nm strndup , +.Nm strndupa .Nd save a copy of a string .Sh LIBRARY .Lb libc @@ -39,7 +41,11 @@ .Ft char * .Fn strdup "const char *str" .Ft char * +.Fn strdupa "const char *str" +.Ft char * .Fn strndup "const char *str" "size_t len" +.Ft char * +.Fn strndupa "const char *str" "size_t len" .Sh DESCRIPTION The .Fn strdup @@ -63,6 +69,19 @@ characters from the string always .Dv NUL terminating the copied string. +.Pp +The +.Fn strdupa +function is identical to +.Fn strdup +but allocates the memory with +.Xr alloca 3 . +Similarly, the +.Fn strndupa +function is identical to +.Fn strndup , +but allocates the memory with +.Xr alloca 3 . .Sh RETURN VALUES If insufficient memory is available, NULL is returned and .Va errno @@ -72,6 +91,7 @@ Otherwise, the .Fn strdup family of functions return a pointer to the copied string. .Sh SEE ALSO +.Xr alloca 3 , .Xr free 3 , .Xr malloc 3 , .Xr wcsdup 3 @@ -84,6 +104,12 @@ The .Fn strndup function is specified by .St -p1003.1-2008 . +The +.Fn strdupa +and +.Fn strndupa +functions are extensions, +taken from glibc. .Sh HISTORY The .Fn strdup @@ -93,3 +119,9 @@ The .Fn strndup function was added in .Fx 7.2 . +The +.Fn strdupa +and +.Fn strndupa +functions were added in +.Fx 15.1 .
