[PATCH v2 09/13] env: Use string pointer instead of indexes in env_get_f()

Marek Behún
2021-10-13T15:47:40Z

From: Marek Behún <marek.behun@nic.cz>

Since we no longer use env_get_char() to access n-th character of
linearized environment data, but rather access the arrays themselves, we
can convert the iteration to use string pointers instead of position
indexes.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
cmd/nvedit.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/cmd/nvedit.c b/cmd/nvedit.c
index 7c99a693ea..6eabd51209 100644
--- a/cmd/nvedit.c
+++ b/cmd/nvedit.c
@@ -706,17 +706,17 @@ char *from_env(const char *envvar)
return ret;
}

-static int env_match(const char *env, const char *s1, int i2)
+static const char *matching_name_get_value(const char *p, const char *name)
{
- while (*s1 == env[i2++] && *s1 != '\0')
- if (*s1++ == '=')
- return i2;
+ while (*name == *p++ && *name != '\0')
+ if (*name++ == '=')
+ return p;

- /* We can look at env[i2-1] because i2 was incremented at least once. */
- if (*s1 == '\0' && env[i2-1] == '=')
- return i2;
+ /* We can look at p[-1] because p was incremented at least once. */
+ if (*name == '\0' && p[-1] == '=')
+ return p;

- return -1;
+ return NULL;
}

/*
@@ -724,8 +724,7 @@ static int env_match(const char *env, const char *s1, int i2)
*/
int env_get_f(const char *name, char *buf, unsigned len)
{
- const char *env;
- int i, nxt;
+ const char *env, *p, *nxt;

if (name == NULL || *name == '\0')
return -1;
@@ -735,20 +734,21 @@ int env_get_f(const char *name, char *buf, unsigned len)
else
env = (const char *)gd->env_addr;

- for (i = 0; env[i] != '\0'; i = nxt + 1) {
- int val, n;
+ for (p = env; *p != '\0'; p = nxt + 1) {
+ const char *value;
+ int n;

- for (nxt = i; env[nxt] != '\0'; ++nxt)
- if (nxt >= CONFIG_ENV_SIZE)
+ for (nxt = p; *nxt != '\0'; ++nxt)
+ if (nxt - env >= CONFIG_ENV_SIZE)
return -1;

- val = env_match(env, name, i);
- if (val < 0)
+ value = matching_name_get_value(p, name);
+ if (value == NULL)
continue;

/* found; copy out */
for (n = 0; n < len; ++n, ++buf) {
- *buf = env[val++];
+ *buf = *value++;
if (*buf == '\0')
return n;
}
--
2.32.0