depinfo: Add support of weakdeps

Weak dependencies are similar to "pre softdep" and are also optional,
but unlike them kmod will not load such modules. Such dependencies are
intended to indicate optional dependencies between modules.

Link: https://politreco.com/2024/08/linux-module-dependencies/
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=61842868de13aa7fd7391c626e889f4d6f1450bf
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>

Author: legionus

utils/depinfo/kmod-depinfo.c

@@ -352,41 +352,45 @@ static int
 depinfo_alias(struct kmod_ctx *ctx, const char *alias, enum alias_need req);
 
 static int
-process_depends(struct kmod_ctx *ctx, const char *depends)
+__process_depends(struct kmod_ctx *ctx, const char *depends, const char *delim, enum alias_need req)
 {
 	int ret = 0;
 	char *s, *str, *token, *saveptr = NULL;
 	s = str = strdup(depends);
 
-	while ((token = strtok_r(str, ",", &saveptr)) != NULL) {
-		if (depinfo_alias(ctx, token, ALIAS_REQUIRED) < 0)
+	while ((token = strtok_r(str, delim, &saveptr)) != NULL) {
+		if (depinfo_alias(ctx, token, req) < 0)
 			ret = -1;
 		str = NULL;
 	}
 	free(s);
 	return ret;
 }
 
+
+static int
+process_depends(struct kmod_ctx *ctx, const char *depends)
+{
+	return __process_depends(ctx, depends, ",", ALIAS_REQUIRED);
+}
+
 static int
 process_soft_depends(struct kmod_ctx *ctx, const char *depends)
 {
-	int ret = 0;
-	char *s, *str, *token, *saveptr = NULL;
 	size_t len = strlen(depends);
-	s = str = strdup(depends);
 
-	if (len > 5 && !strncmp("pre: ", s, 5))
-		str += 5;
-	else if (len > 6 && !strncmp("post: ", s, 6))
-		str += 6;
+	if (len > 5 && !strncmp("pre: ", depends, 5))
+		depends += 5;
+	else if (len > 6 && !strncmp("post: ", depends, 6))
+		depends += 6;
 
-	while ((token = strtok_r(str, " ", &saveptr)) != NULL) {
-		if (depinfo_alias(ctx, token, ALIAS_OPTIONAL) < 0)
-			ret = -1;
-		str = NULL;
-	}
-	free(s);
-	return ret;
+	return __process_depends(ctx, depends, " ", ALIAS_OPTIONAL);
+}
+
+static int
+process_weak_depends(struct kmod_ctx *ctx, const char *depends)
+{
+	return __process_depends(ctx, depends, " ", ALIAS_OPTIONAL);
 }
 
 static int
@@ -440,6 +444,9 @@ depinfo(struct kmod_ctx *ctx, struct kmod_module *mod)
 			} else if (!strcmp("softdep", key)) {
 				if (process_soft_depends(ctx, val) < 0)
 					ret = -1;
+			} else if (!strcmp("weakdep", key)) {
+				if (process_weak_depends(ctx, val) < 0)
+					ret = -1;
 			}
 		}
 		if ((opts & SHOW_FIRMWARE) && !strcmp("firmware", key))