strv: multiple cleanups

- turn strv_merge into strv_extend_strv.
   appending strv b to the end of strv a instead of creating a new strv
- strv_append: remove in favor of strv_extend and strv_push.
- strv_remove: write slightly more elegant
- strv_remove_prefix: remove unused function
- strv_overlap: use strv_contains
- strv_printf: STRV_FOREACH handles NULL correctly

3 files changed, 52 insertions, 195 deletions

diff --git a/src/shared/path-lookup.c b/src/shared/path-lookup.c
index 1a47ea9ce7..e2ca9420d9 100644
--- a/src/shared/path-lookup.c
+++ b/src/shared/path-lookup.c
@@ -90,9 +90,9 @@ static char** user_dirs(
         };
 
         const char *home, *e;
-        char *config_home = NULL, *data_home = NULL;
-        char **config_dirs = NULL, **data_dirs = NULL;
-        char **r = NULL, **t;
+        _cleanup_free_ char *config_home = NULL, *data_home = NULL;
+        _cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
+        char **r = NULL;
 
         /* Implement the mechanisms defined in
          *
@@ -150,89 +150,48 @@ static char** user_dirs(
                 goto fail;
 
         /* Now merge everything we found. */
-        if (generator_early) {
-                t = strv_append(r, generator_early);
-                if (!t)
+        if (generator_early)
+                if (strv_extend(&r, generator_early) < 0)
                         goto fail;
-                strv_free(r);
-                r = t;
-        }
 
-        if (config_home) {
-                t = strv_append(r, config_home);
-                if (!t)
+        if (config_home)
+                if (strv_extend(&r, config_home) < 0)
                         goto fail;
-                strv_free(r);
-                r = t;
-        }
 
-        if (!strv_isempty(config_dirs)) {
-                t = strv_merge_concat(r, config_dirs, "/systemd/user");
-                if (!t)
-                        goto finish;
-                strv_free(r);
-                r = t;
-        }
+        if (!strv_isempty(config_dirs))
+                if (strv_extend_strv_concat(&r, config_dirs, "/systemd/user") < 0)
+                        goto fail;
 
-        t = strv_merge(r, (char**) config_unit_paths);
-        if (!t)
+        if (strv_extend_strv(&r, (char**) config_unit_paths) < 0)
                 goto fail;
-        strv_free(r);
-        r = t;
 
-        if (generator) {
-                t = strv_append(r, generator);
-                if (!t)
+        if (generator)
+                if (strv_extend(&r, generator) < 0)
                         goto fail;
-                strv_free(r);
-                r = t;
-        }
 
-        if (data_home) {
-                t = strv_append(r, data_home);
-                if (!t)
+        if (data_home)
+                if (strv_extend(&r, data_home) < 0)
                         goto fail;
-                strv_free(r);
-                r = t;
-        }
 
-        if (!strv_isempty(data_dirs)) {
-                t = strv_merge_concat(r, data_dirs, "/systemd/user");
-                if (!t)
+        if (!strv_isempty(data_dirs))
+                if (strv_extend_strv_concat(&r, data_dirs, "/systemd/user") < 0)
                         goto fail;
-                strv_free(r);
-                r = t;
-        }
 
-        t = strv_merge(r, (char**) data_unit_paths);
-        if (!t)
+        if (strv_extend_strv(&r, (char**) data_unit_paths) < 0)
                 goto fail;
-        strv_free(r);
-        r = t;
 
-        if (generator_late) {
-                t = strv_append(r, generator_late);
-                if (!t)
+        if (generator_late)
+                if (strv_extend(&r, generator_late) < 0)
                         goto fail;
-                strv_free(r);
-                r = t;
-        }
 
         if (!path_strv_make_absolute_cwd(r))
                 goto fail;
 
-finish:
-        free(config_home);
-        strv_free(config_dirs);
-        free(data_home);
-        strv_free(data_dirs);
-
         return r;
 
 fail:
         strv_free(r);
-        r = NULL;
-        goto finish;
+        return NULL;
 }
 
 int lookup_paths_init(
diff --git a/src/shared/strv.c b/src/shared/strv.c
index 607c221ae6..13deba7be7 100644
--- a/src/shared/strv.c
+++ b/src/shared/strv.c
@@ -166,72 +166,38 @@ char **strv_new(const char *x, ...) {
         return r;
 }
 
-char **strv_merge(char **a, char **b) {
-        char **r, **k;
-
-        if (!a)
-                return strv_copy(b);
-
-        if (!b)
-                return strv_copy(a);
-
-        r = new(char*, strv_length(a) + strv_length(b) + 1);
-        if (!r)
-                return NULL;
-
-        for (k = r; *a; k++, a++) {
-                *k = strdup(*a);
-                if (!*k)
-                        goto fail;
-        }
+int strv_extend_strv(char ***a, char **b) {
+        int r;
+        char **s;
 
-        for (; *b; k++, b++) {
-                *k = strdup(*b);
-                if (!*k)
-                        goto fail;
+        STRV_FOREACH(s, b) {
+                r = strv_extend(a, *s);
+                if (r < 0)
+                        return r;
         }
 
-        *k = NULL;
-        return r;
-
-fail:
-        strv_free(r);
-        return NULL;
+        return 0;
 }
 
-char **strv_merge_concat(char **a, char **b, const char *suffix) {
-        char **r, **k;
-
-        /* Like strv_merge(), but appends suffix to all strings in b, before adding */
+int strv_extend_strv_concat(char ***a, char **b, const char *suffix) {
+        int r;
+        char **s;
 
-        if (!b)
-                return strv_copy(a);
+        STRV_FOREACH(s, b) {
+                char *v;
 
-        r = new(char*, strv_length(a) + strv_length(b) + 1);
-        if (!r)
-                return NULL;
+                v = strappend(*s, suffix);
+                if (!v)
+                        return -ENOMEM;
 
-        k = r;
-        if (a)
-                for (; *a; k++, a++) {
-                        *k = strdup(*a);
-                        if (!*k)
-                                goto fail;
+                r = strv_push(a, v);
+                if (r < 0) {
+                        free(v);
+                        return r;
                 }
-
-        for (; *b; k++, b++) {
-                *k = strappend(*b, suffix);
-                if (!*k)
-                        goto fail;
         }
 
-        *k = NULL;
-        return r;
-
-fail:
-        strv_free(r);
-        return NULL;
-
+        return 0;
 }
 
 char **strv_split(const char *s, const char *separator) {
@@ -393,37 +359,6 @@ char *strv_join_quoted(char **l) {
         return NULL;
 }
 
-char **strv_append(char **l, const char *s) {
-        char **r, **k;
-
-        if (!l)
-                return strv_new(s, NULL);
-
-        if (!s)
-                return strv_copy(l);
-
-        r = new(char*, strv_length(l)+2);
-        if (!r)
-                return NULL;
-
-        for (k = r; *l; k++, l++) {
-                *k = strdup(*l);
-                if (!*k)
-                        goto fail;
-        }
-
-        k[0] = strdup(s);
-        if (!k[0])
-                goto fail;
-
-        k[1] = NULL;
-        return r;
-
-fail:
-        strv_free(r);
-        return NULL;
-}
-
 int strv_push(char ***l, char *value) {
         char **c;
         unsigned n;
@@ -484,40 +419,11 @@ char **strv_remove(char **l, const char *s) {
         /* Drops every occurrence of s in the string list, edits
          * in-place. */
 
-        for (f = t = l; *f; f++) {
-
-                if (streq(*f, s)) {
-                        free(*f);
-                        continue;
-                }
-
-                *(t++) = *f;
-        }
-
-        *t = NULL;
-        return l;
-}
-
-char **strv_remove_prefix(char **l, const char *s) {
-        char **f, **t;
-
-        if (!l)
-                return NULL;
-
-        assert(s);
-
-        /* Drops every occurrence of a string prefixed with s in the
-         * string list, edits in-place. */
-
-        for (f = t = l; *f; f++) {
-
-                if (startswith(*f, s)) {
+        for (f = t = l; *f; f++)
+                if (streq(*f, s))
                         free(*f);
-                        continue;
-                }
-
-                *(t++) = *f;
-        }
+                else
+                        *(t++) = *f;
 
         *t = NULL;
         return l;
@@ -586,14 +492,11 @@ char **strv_split_nulstr(const char *s) {
 }
 
 bool strv_overlap(char **a, char **b) {
-        char **i, **j;
+        char **i;
 
-        STRV_FOREACH(i, a) {
-                STRV_FOREACH(j, b) {
-                        if (streq(*i, *j))
-                                return true;
-                }
-        }
+        STRV_FOREACH(i, a)
+                if (strv_contains(b, *i))
+                        return true;
 
         return false;
 }
@@ -616,9 +519,6 @@ char **strv_sort(char **l) {
 void strv_print(char **l) {
         char **s;
 
-        if (!l)
-                return;
-
         STRV_FOREACH(s, l)
                 puts(*s);
 }
diff --git a/src/shared/strv.h b/src/shared/strv.h
index daf9ad0d0b..715bc5419c 100644
--- a/src/shared/strv.h
+++ b/src/shared/strv.h
@@ -36,14 +36,12 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(char**, strv_free);
 char **strv_copy(char * const *l);
 unsigned strv_length(char * const *l) _pure_;
 
-char **strv_merge(char **a, char **b);
-char **strv_merge_concat(char **a, char **b, const char *suffix);
-char **strv_append(char **l, const char *s);
+int strv_extend_strv(char ***a, char **b);
+int strv_extend_strv_concat(char ***a, char **b, const char *suffix);
 int strv_extend(char ***l, const char *value);
 int strv_push(char ***l, char *value);
 
 char **strv_remove(char **l, const char *s);
-char **strv_remove_prefix(char **l, const char *s);
 char **strv_uniq(char **l);
 
 #define strv_contains(l, s) (!!strv_find((l), (s)))