1 files changed, 153 insertions, 0 deletions
diff --git a/src/scope.c b/src/scope.c
new file mode 100644
index 0000000..290dfd6
--- /dev/null
+++ b/src/scope.c
@@ -0,0 +1,153 @@
+#include <stddef.h>
+#include <stdlib.h>
+
+#include <posthaste/scope.h>
+#include <posthaste/debug.h>
+#include <posthaste/vec.h>
+
+struct scope {
+	size_t id;
+	struct scope *parent;
+
+	const char *fname;
+	const char *buf;
+
+	struct vec visible;
+};
+
+struct vec scopes = {0};
+
+struct scope *create_scope()
+{
+	static size_t counter = 0;
+	if (vec_uninit(scopes)) {
+		scopes = vec_create(sizeof(struct scope *));
+	}
+
+	struct scope *scope = calloc(1, sizeof(struct scope));
+	if (!scope)
+		return NULL;
+
+	scope->visible = vec_create(sizeof(struct ast *));
+	scope->id = counter++;
+
+	vect_append(struct scope *, scopes, &scope);
+	return scope;
+}
+
+void scope_add_scope(struct scope *parent, struct scope *scope)
+{
+	scope->parent = parent;
+	scope->fname = parent->fname;
+	scope->buf = parent->buf;
+}
+
+void scope_set_file(struct scope *scope, const char *fname, const char *buf)
+{
+	scope->fname = fname;
+	scope->buf = buf;
+}
+
+struct ast *scope_find(struct scope *scope, char *id)
+{
+	/* not particularly fast, but good enough for now */
+	foreach_vec(vi, scope->visible) {
+		struct ast *n = vect_at(struct ast *, scope->visible, vi);
+		if (same_id(n->id, id))
+			return n;
+	}
+
+	return NULL;
+}
+
+struct ast *file_scope_find(struct scope *scope, char *id)
+{
+	struct ast *exists = scope_find(scope, id);
+	if (exists)
+		return exists;
+
+	if (scope->parent)
+		return file_scope_find(scope->parent, id);
+
+	return NULL;
+}
+
+int scope_add_var(struct scope *scope, struct ast *var)
+{
+	struct ast *exists = scope_find(scope, var_id(var));
+	if (exists) {
+		semantic_error(scope, var, "var redefined");
+		semantic_error(scope, exists, "previously here");
+		return -1;
+	}
+
+	vect_append(struct ast *, scope->visible, &var);
+	return 0;
+}
+
+int scope_add_formal(struct scope *scope, struct ast *formal)
+{
+	struct ast *exists = scope_find(scope, formal_id(formal));
+	if (exists) {
+		semantic_error(scope, formal, "formal redefined");
+		semantic_error(scope, exists, "previously here");
+		return -1;
+	}
+
+	vect_append(struct ast *, scope->visible, &formal);
+	return 0;
+}
+
+int scope_add_proc(struct scope *scope, struct ast *proc)
+{
+	struct ast *exists = scope_find(scope, proc_id(proc));
+	if (exists) {
+		semantic_error(scope, proc, "proc redefined");
+		semantic_error(scope, exists, "previously here");
+		return -1;
+	}
+
+	vect_append(struct ast *, scope->visible, &proc);
+	return 0;
+}
+
+int scope_add_func(struct scope *scope, struct ast *func)
+{
+	struct ast *exists = scope_find(scope, func_id(func));
+	if (exists) {
+		semantic_error(scope, func, "func redefined");
+		semantic_error(scope, exists, "previously here");
+		return -1;
+	}
+
+	vect_append(struct ast *, scope->visible, &func);
+	return 0;
+}
+
+static void destroy_scope(struct scope *scope)
+{
+	vec_destroy(&scope->visible);
+	free(scope);
+}
+
+void destroy_scopes()
+{
+	foreach_vec(si, scopes) {
+		struct scope *s = vect_at(struct scope *, scopes, si);
+		destroy_scope(s);
+	}
+
+	vec_destroy(&scopes);
+}
+
+void semantic_error(struct scope *scope, struct ast *n, const char *msg, ...)
+{
+	va_list args;
+	va_start(args, msg);
+	struct src_issue issue;
+	issue.loc = n->loc;
+	issue.fname = scope->fname;
+	issue.buf = scope->buf;
+	vsrc_issue(issue, msg, args);
+	va_end(args);
+}