main: add pkg_queue for mergemaster operation

main.c

@@ -42,16 +42,37 @@ print_libs(pkg_t *pkg, void *unused)
 		printf("%s ", pkg->libs);
 }
 
+typedef struct pkg_queue_ {
+	struct pkg_queue_ *prev, *next;
+	const char *package;
+} pkg_queue_t;
+
+static pkg_queue_t *
+pkg_queue_push(pkg_queue_t *parent, const char *package)
+{
+	pkg_queue_t *pkgq = calloc(sizeof(pkg_queue_t), 1);
+
+	pkgq->package = package;
+	pkgq->prev = parent;
+	if (pkgq->prev != NULL)
+		pkgq->prev->next = pkgq;
+
+	return pkgq;
+}
+
 int
-handle_package(const char *package)
+pkg_queue_walk(pkg_queue_t *head)
+{
+	int wanted_something = 0;
+	pkg_queue_t *pkgq;
+
+	foreach_list_entry(head, pkgq)
 	{
 		pkg_t *pkg;
 
-	pkg = pkg_find(package);
+		pkg = pkg_find(pkgq->package);
 		if (pkg)
 		{
-		int wanted_something = 0;
-
 			if (want_cflags)
 			{
 				wanted_something++;
@@ -63,22 +84,27 @@ handle_package(const char *package)
 				wanted_something++;
 				pkg_traverse(pkg, print_libs, NULL);
 			}
-
-		if (wanted_something)
-			printf("\n");
 		}
 		else
 		{
-		fprintf(stderr, "dependency '%s' could not be satisfied, see PKG_CONFIG_PATH.\n", package);
+			fprintf(stderr, "dependency '%s' could not be satisfied, see PKG_CONFIG_PATH.\n", pkgq->package);
-		return -1;
+			return EXIT_FAILURE;
 		}
 	}
 
+	if (wanted_something)
+		printf("\n");
+
+	return EXIT_SUCCESS;
+}
+
 int
 main(int argc, const char *argv[])
 {
 	int ret;
 	poptContext opt_context;
+	pkg_queue_t *pkgq = NULL;
+	pkg_queue_t *pkgq_head = NULL;
 
 	struct poptOption options[] = {
 		{ "libs", 0, POPT_ARG_NONE, &want_libs, 0, "output all linker flags" },
@@ -103,10 +129,12 @@ main(int argc, const char *argv[])
 		if (package == NULL)
 			break;
 
-		handle_package(package);
+		pkgq = pkg_queue_push(pkgq, package);
+		if (pkgq_head == NULL)
+			pkgq_head = pkgq;
 	}
 
 	poptFreeContext(opt_context);
 
-	return EXIT_SUCCESS;
+	return pkg_queue_walk(pkgq_head);
 }