Add symbol scoping for proper parsing.

1 files changed, 47 insertions, 0 deletions

diff --git a/scope.c b/scope.c
new file mode 100644
index 00000000..3f86f622
--- /dev/null
+++ b/scope.c
@@ -0,0 +1,47 @@
+/*
+ * Symbol scoping.
+ *
+ * This is pretty trivial.
+ */
+#include <stdlib.h>
+#include <string.h>
+
+#include "lib.h"
+#include "symbol.h"
+#include "scope.h"
+
+static struct scope
+	 base_scope = { .next = &base_scope },
+	*current_scope = &base_scope;
+
+void bind_scope(struct symbol *sym)
+{
+	add_symbol(&current_scope->symbols, sym);
+}
+
+void start_symbol_scope(void)
+{
+	struct scope *scope = __alloc_bytes(sizeof(*scope));
+	memset(scope, 0, sizeof(*scope));
+	scope->next = current_scope;
+	current_scope = scope;
+}
+
+static void remove_symbol_scope(struct symbol *sym)
+{
+	struct symbol **ptr = sym->id_list;
+
+	while (*ptr != sym)
+		ptr = &(*ptr)->next_id;
+	*ptr = sym->next_id;
+}
+
+void end_symbol_scope(void)
+{
+	struct scope *scope = current_scope;
+	struct symbol_list *symbols = scope->symbols;
+
+	current_scope = scope->next;
+	scope->symbols = NULL;
+	symbol_iterate(symbols, remove_symbol_scope);
+}