basic/strv: introduce STRV_IGNORE macro (#3601)

to hide casting of '-1' strings and make code cleaner.

diff --git a/src/basic/strv.c b/src/basic/strv.c
index 87b11d00dc1eeca3eb80b9377ce8fceefc6ada71..47f7a72959285046981e2dfdbfaddcabae077585 100644 (file)
--- a/src/basic/strv.c
+++ b/src/basic/strv.c
@@ -139,16 +139,16 @@ char **strv_new_ap(const char *x, va_list ap) {
         va_list aq;
 
         /* As a special trick we ignore all listed strings that equal
-         * (const char*) -1. This is supposed to be used with the
+         * STRV_IGNORE. This is supposed to be used with the
          * STRV_IFNOTNULL() macro to include possibly NULL strings in
          * the string list. */
 
         if (x) {
-                n = x == (const char*) -1 ? 0 : 1;
+                n = x == STRV_IGNORE ? 0 : 1;
 
                 va_copy(aq, ap);
                 while ((s = va_arg(aq, const char*))) {
-                        if (s == (const char*) -1)
+                        if (s == STRV_IGNORE)
                                 continue;
 
                         n++;
@@ -162,7 +162,7 @@ char **strv_new_ap(const char *x, va_list ap) {
                 return NULL;
 
         if (x) {
-                if (x != (const char*) -1) {
+                if (x != STRV_IGNORE) {
                         a[i] = strdup(x);
                         if (!a[i])
                                 goto fail;
@@ -171,7 +171,7 @@ char **strv_new_ap(const char *x, va_list ap) {
 
                 while ((s = va_arg(ap, const char*))) {
 
-                        if (s == (const char*) -1)
+                        if (s == STRV_IGNORE)
                                 continue;
 
                         a[i] = strdup(s);

diff --git a/src/basic/strv.h b/src/basic/strv.h
index 591a452e90d032234b6f9e594cae0ddccccaafa8..c95a637b43d811b229b5eddf7328c2970142207a 100644 (file)
--- a/src/basic/strv.h
+++ b/src/basic/strv.h
@@ -77,8 +77,10 @@ bool strv_equal(char **a, char **b);
 char **strv_new(const char *x, ...) _sentinel_;
 char **strv_new_ap(const char *x, va_list ap);
 
+#define STRV_IGNORE ((const char *) -1)
+
 static inline const char* STRV_IFNOTNULL(const char *x) {
-        return x ? x : (const char *) -1;
+        return x ? x : STRV_IGNORE;
 }
 
 static inline bool strv_isempty(char * const *l) {