Add a pkg command for producing a dependency graph

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>

main/Makemodule.am

@@ -28,6 +28,9 @@ pkg_SOURCES += main/cmd/install.c
 pkg_SOURCES += main/cmd/buildstrategy/buildstrategy.h
 pkg_SOURCES += main/cmd/buildstrategy/buildstrategy.c
 
+# depgraph command
+pkg_SOURCES += main/cmd/depgraph.c
+
 # unpack command
 pkg_SOURCES += main/cmd/unpack.c
 

main/cmd/depgraph.c

@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: ISC */
+#include <stdbool.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+
+#include "depgraph.h"
+#include "command.h"
+
+static const struct option long_opts[] = {
+	{ "no-dependencies", no_argument, NULL, 'd' },
+	{ "repo-dir", required_argument, NULL, 'R' },
+	{ NULL, 0, NULL, 0 },
+};
+
+static const char *short_opts = "dR:";
+
+static void print_dot_graph(struct pkg_dep_list *list)
+{
+	struct pkg_dep_node *it;
+	size_t i;
+
+	printf("digraph dependencies {\n");
+
+	for (it = list->head; it != NULL; it = it->next) {
+		for (i = 0; i < it->num_deps; ++i) {
+			printf("\t\"%s\" -> \"%s\";\n",
+			       it->name, it->deps[i]->name);
+		}
+	}
+
+	printf("}\n");
+}
+
+static int cmd_depgraph(int argc, char **argv)
+{
+	int i, repofd = AT_FDCWD, ret = EXIT_FAILURE;
+	struct pkg_dep_list list;
+	bool resolve_deps = true;
+
+	memset(&list, 0, sizeof(list));
+
+	for (;;) {
+		i = getopt_long(argc, argv, short_opts, long_opts, NULL);
+		if (i == -1)
+			break;
+
+		switch (i) {
+		case 'd':
+			resolve_deps = false;
+			break;
+		case 'R':
+			if (repofd != AT_FDCWD) {
+				fputs("repo specified more than once\n",
+				      stderr);
+				tell_read_help(argv[0]);
+				goto out;
+			}
+			repofd = open(optarg, O_RDONLY | O_DIRECTORY);
+			if (repofd < 0) {
+				perror(optarg);
+				goto out;
+			}
+			break;
+		default:
+			tell_read_help(argv[0]);
+			goto out;
+		}
+	}
+
+	for (i = optind; i < argc; ++i) {
+		if (append_pkg(&list, argv[i]) == NULL)
+			goto out;
+	}
+
+	if (resolve_deps) {
+		if (collect_dependencies(repofd, &list))
+			goto out;
+	}
+
+	print_dot_graph(&list);
+	ret = EXIT_SUCCESS;
+out:
+	if (repofd != AT_FDCWD)
+		close(repofd);
+	pkg_list_cleanup(&list);
+	return ret;
+}
+
+static command_t depgraph = {
+	.cmd = "depgraph",
+	.usage = "[OPTIONS...] PACKAGES...",
+	.s_desc = "produces a DOT language dependency graph",
+	.l_desc =
+"Fetches a number of packages from a repository directory by name and\n"
+"produces a DOT language dependency graph for the packages.\n"
+"\n"
+"Possible options:\n"
+"  --repo-dir, -R <path>     Specify the input repository path to fetch the\n"
+"                            packages from.\n"
+"  --no-dependencies, -d     Do not resolve dependencies, only process the\n"
+"                            packages listed on the command line.\n",
+	.run_cmd = cmd_depgraph,
+};
+
+REGISTER_COMMAND(depgraph)