toolchain: add a program for compiling ipc interface definitions

ifc can be used to compile .if files into self-contained header-only C
libraries, which can be used to send/receive messages that conform
to the described interface.

toolchain/ifc/interface.c

@@ -0,0 +1,60 @@
+#include "interface.h"
+
+#include "msg.h"
+
+#include <blue/ds/string.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct interface_definition *interface_definition_create(const char *name)
+{
+	struct interface_definition *out = malloc(sizeof *out);
+	if (!out) {
+		return NULL;
+	}
+
+	memset(out, 0x0, sizeof *out);
+
+	out->if_name = b_strdup(name);
+
+	return out;
+}
+
+void interface_definition_destroy(struct interface_definition *iface)
+{
+	b_queue_entry *entry = b_queue_pop_front(&iface->if_msg);
+	while (entry) {
+		struct msg_definition *msg
+			= b_unbox(struct msg_definition, entry, msg_entry);
+		msg_definition_destroy(msg);
+		entry = b_queue_pop_front(&iface->if_msg);
+	}
+
+	free(iface->if_name);
+	free(iface);
+}
+
+bool interface_definition_has_msg(
+	const struct interface_definition *iface,
+	const char *name)
+{
+	b_queue_entry *entry = b_queue_first(&iface->if_msg);
+
+	while (entry) {
+		struct msg_definition *msg
+			= b_unbox(struct msg_definition, entry, msg_entry);
+		if (!strcmp(msg->msg_name, name)) {
+			return true;
+		}
+		entry = b_queue_next(entry);
+	}
+
+	return false;
+}
+
+void interface_definition_add_msg(
+	struct interface_definition *iface,
+	struct msg_definition *msg)
+{
+	b_queue_push_back(&iface->if_msg, &msg->msg_entry);
+}