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/ctx.c

@@ -0,0 +1,52 @@
+#include "ctx.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+static void init_builtin_types(struct ctx *ctx)
+{
+	for (size_t i = 0; i < TYPE_OTHER; i++) {
+		ctx->ctx_builtin_types[i].ty_id = i;
+	}
+}
+
+struct ctx *ctx_create(void)
+{
+	struct ctx *out = malloc(sizeof *out);
+	if (!out) {
+		return NULL;
+	}
+
+	memset(out, 0x0, sizeof *out);
+
+	init_builtin_types(out);
+
+	return out;
+}
+
+void ctx_destroy(struct ctx *ctx)
+{
+	free(ctx);
+}
+
+const struct type *ctx_get_type(struct ctx *ctx, const char *name)
+{
+	if (!strcmp(name, "string")) {
+		return ctx_get_builtin_type(ctx, TYPE_STRING);
+	}
+
+	if (!strcmp(name, "int")) {
+		return ctx_get_builtin_type(ctx, TYPE_INT);
+	}
+
+	return NULL;
+}
+
+const struct type *ctx_get_builtin_type(struct ctx *ctx, enum type_id id)
+{
+	if (id >= TYPE_OTHER) {
+		return NULL;
+	}
+
+	return &ctx->ctx_builtin_types[id];
+}