MINOR: config: centralize the ".if"/".elif" condition parser and evaluator

Instead of duplicating the condition evaluations, let's have a single
function cfg_eval_condition() that returns true/false/error. It takes
less code and will ease its extension.

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 0048a12cbb13277b4e464c944399bb64be030f91..e5585ff609251e68d820001c6f205df4977b553a 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1634,6 +1634,25 @@ static int cfg_parse_global_def_path(char **args, int section_type, struct proxy
        return ret;
 }
 
+/* evaluate a condition on a .if/.elif line. The condition is already tokenized
+ * in <err>. Returns -1 on error (in which case err is filled with a message,
+ * and only in this case), 0 if the condition is false, 1 if it's true.
+ */
+static int cfg_eval_condition(char **args, char **err)
+{
+       char *end;
+       long val;
+
+       if (!*args[0]) /* note: empty = false */
+               return 0;
+
+       val = strtol(args[0], &end, 0);
+       if (end && *end == '\0')
+               return val != 0;
+
+       memprintf(err, "unparsable conditional expression '%s'.\n", args[0]);
+       return -1;
+}
 
 /*
  * This function reads and parses the configuration file given in the argument.
@@ -1848,6 +1867,9 @@ next_line:
                /* check for config macros */
                if (*args[0] == '.') {
                        if (strcmp(args[0], ".if") == 0) {
+                               char *errmsg = NULL;
+                               int cond;
+
                                nested_cond_lvl++;
                                if (nested_cond_lvl >= MAXNESTEDCONDS) {
                                        ha_alert("parsing [%s:%d]: too many nested '.if', max is %d.\n", file, linenum, MAXNESTEDCONDS);
@@ -1862,20 +1884,28 @@ next_line:
                                     nested_conds[nested_cond_lvl - 1] == NESTED_COND_ELIF_SKIP ||
                                     nested_conds[nested_cond_lvl - 1] == NESTED_COND_ELSE_DROP)) {
                                        nested_conds[nested_cond_lvl] = NESTED_COND_IF_SKIP;
-                               } else if (!*args[1] || *args[1] == '0') {
-                                       /* empty = false */
-                                       nested_conds[nested_cond_lvl] = NESTED_COND_IF_DROP;
-                               } else if (atoi(args[1]) != 0) {
-                                       /* true */
-                                       nested_conds[nested_cond_lvl] = NESTED_COND_IF_TAKE;
-                               } else {
-                                       ha_alert("parsing [%s:%d]: unparsable conditional expression '%s'.\n", file, linenum, args[1]);
+                                       goto next_line;
+                               }
+
+                               cond = cfg_eval_condition(args + 1, &errmsg);
+                               if (cond < 0) {
+                                       ha_alert("parsing [%s:%d]: %s in '.if'\n", file, linenum, errmsg);
+                                       free(errmsg);
                                        err_code |= ERR_ALERT | ERR_FATAL | ERR_ABORT;
                                        goto err;
                                }
+
+                               if (cond)
+                                       nested_conds[nested_cond_lvl] = NESTED_COND_IF_TAKE;
+                               else
+                                       nested_conds[nested_cond_lvl] = NESTED_COND_IF_DROP;
+
                                goto next_line;
                        }
                        else if (strcmp(args[0], ".elif") == 0) {
+                               char *errmsg = NULL;
+                               int cond;
+
                                if (!nested_cond_lvl) {
                                        ha_alert("parsing [%s:%d]: lone '.elif' with no matching '.if'.\n", file, linenum);
                                        err_code |= ERR_ALERT | ERR_FATAL | ERR_ABORT;
@@ -1894,17 +1924,22 @@ next_line:
                                    nested_conds[nested_cond_lvl] == NESTED_COND_ELIF_TAKE ||
                                    nested_conds[nested_cond_lvl] == NESTED_COND_ELIF_SKIP) {
                                        nested_conds[nested_cond_lvl] = NESTED_COND_ELIF_SKIP;
-                               } else if (!*args[1] || *args[1] == '0') {
-                                       /* empty = false */
-                                       nested_conds[nested_cond_lvl] = NESTED_COND_ELIF_DROP;
-                               } else if (atoi(args[1]) != 0) {
-                                       /* true */
-                                       nested_conds[nested_cond_lvl] = NESTED_COND_ELIF_TAKE;
-                               } else {
-                                       ha_alert("parsing [%s:%d]: unparsable conditional expression '%s'.\n", file, linenum, args[1]);
+                                       goto next_line;
+                               }
+
+                               cond = cfg_eval_condition(args + 1, &errmsg);
+                               if (cond < 0) {
+                                       ha_alert("parsing [%s:%d]: %s in '.elif'\n", file, linenum, errmsg);
+                                       free(errmsg);
                                        err_code |= ERR_ALERT | ERR_FATAL | ERR_ABORT;
                                        goto err;
                                }
+
+                               if (cond)
+                                       nested_conds[nested_cond_lvl] = NESTED_COND_ELIF_TAKE;
+                               else
+                                       nested_conds[nested_cond_lvl] = NESTED_COND_ELIF_DROP;
+
                                goto next_line;
                        }
                        else if (strcmp(args[0], ".else") == 0) {