99 lines
2.8 KiB
Diff
99 lines
2.8 KiB
Diff
commit a6ccce23afc2a09a17ac2a86a2b726b58df609df
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Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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Date: Thu Feb 9 10:36:57 2023 -0300
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stdlib: Simplify getenv
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And remove _STRING_ARCH_unaligned usage.
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Checked on x86_64-linux-gnu and i686-linux-gnu.
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Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
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diff --git a/stdlib/getenv.c b/stdlib/getenv.c
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index e359cc925f5a7dcf..0cfaf1412a65cca5 100644
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--- a/stdlib/getenv.c
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+++ b/stdlib/getenv.c
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@@ -15,76 +15,22 @@
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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-#include <endian.h>
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-#include <errno.h>
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-#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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-
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-/* Return the value of the environment variable NAME. This implementation
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- is tuned a bit in that it assumes no environment variable has an empty
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- name which of course should always be true. We have a special case for
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- one character names so that for the general case we can assume at least
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- two characters which we can access. By doing this we can avoid using the
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- `strncmp' most of the time. */
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char *
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getenv (const char *name)
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{
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- char **ep;
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- uint16_t name_start;
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-
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if (__environ == NULL || name[0] == '\0')
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return NULL;
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- if (name[1] == '\0')
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- {
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- /* The name of the variable consists of only one character. Therefore
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- the first two characters of the environment entry are this character
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- and a '=' character. */
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-#if __BYTE_ORDER == __LITTLE_ENDIAN || !_STRING_ARCH_unaligned
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- name_start = ('=' << 8) | *(const unsigned char *) name;
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-#else
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- name_start = '=' | ((*(const unsigned char *) name) << 8);
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-#endif
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- for (ep = __environ; *ep != NULL; ++ep)
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- {
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-#if _STRING_ARCH_unaligned
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- uint16_t ep_start = *(uint16_t *) *ep;
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-#else
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- uint16_t ep_start = (((unsigned char *) *ep)[0]
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- | (((unsigned char *) *ep)[1] << 8));
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-#endif
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- if (name_start == ep_start)
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- return &(*ep)[2];
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- }
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- }
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- else
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+ size_t len = strlen (name);
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+ for (char **ep = __environ; *ep != NULL; ++ep)
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{
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- size_t len = strlen (name);
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-#if _STRING_ARCH_unaligned
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- name_start = *(const uint16_t *) name;
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-#else
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- name_start = (((const unsigned char *) name)[0]
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- | (((const unsigned char *) name)[1] << 8));
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-#endif
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- len -= 2;
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- name += 2;
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-
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- for (ep = __environ; *ep != NULL; ++ep)
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- {
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-#if _STRING_ARCH_unaligned
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- uint16_t ep_start = *(uint16_t *) *ep;
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-#else
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- uint16_t ep_start = (((unsigned char *) *ep)[0]
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- | (((unsigned char *) *ep)[1] << 8));
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-#endif
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-
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- if (name_start == ep_start && !strncmp (*ep + 2, name, len)
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- && (*ep)[len + 2] == '=')
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- return &(*ep)[len + 3];
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- }
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+ if (name[0] == (*ep)[0]
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+ && strncmp (name, *ep, len) == 0 && (*ep)[len] == '=')
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+ return *ep + len + 1;
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}
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return NULL;
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