1 files changed, 217 insertions, 0 deletions
diff --git a/src/scope.c b/src/scope.c
new file mode 100644
index 0000000..869e0d6
--- /dev/null
+++ b/src/scope.c
@@ -0,0 +1,217 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+/* Copyright 2024 Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
+
+/** @file scope.c
+ *
+ * Implementations for scope handling stuff.
+ */
+
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include <fwd/debug.h>
+#include <fwd/scope.h>
+
+struct scope *create_scope()
+{
+	/* if I ever try making the parser multithreaded, this should be atomic. */
+	static size_t counter = 0;
+
+	struct scope *scope = calloc(1, sizeof(struct scope));
+	if (!scope) {
+		internal_error("ran out of memory allocating scope");
+		return NULL;
+	}
+
+	scope->number = counter++;
+	return scope;
+}
+
+static void destroy_visible(struct visible *visible)
+{
+	struct visible *prev = visible, *cur;
+	if (prev)
+		do {
+			cur = prev->next;
+			free(prev);
+		} while ((prev = cur));
+}
+
+void destroy_scope(struct scope *scope)
+{
+	if (!scope)
+		return;
+
+	if (!scope->parent) {
+		free((void *)scope->fctx.fbuf);
+		free((void *)scope->fctx.fname);
+	}
+
+	destroy_visible(scope->symbols);
+
+	struct scope *prev = scope->children, *cur;
+	if (prev)
+		do {
+			cur = prev->next;
+			destroy_scope(prev);
+		} while ((prev = cur));
+
+	free(scope);
+}
+
+static struct visible *create_visible(char *id, struct ast *node)
+{
+	struct visible *visible = calloc(1, sizeof(struct visible));
+	if (!visible)
+		return NULL;
+
+	visible->id = id;
+	visible->node = node;
+	return visible;
+}
+
+struct visible *create_var(struct scope *scope, char *id, struct ast *var)
+{
+	struct visible *n = create_visible(id, var);
+	if (!n)
+		return NULL;
+
+	n->next = scope->symbols;
+	scope->symbols = n;
+
+	return n;
+}
+
+struct visible *create_proc(struct scope *scope, char *id, struct ast *proc)
+{
+	struct visible *n = create_visible(id, proc);
+	if (!n)
+		return NULL;
+
+	n->next = scope->symbols;
+	scope->symbols = n;
+
+	return n;
+}
+
+int scope_add_var(struct scope *scope, struct ast *var)
+{
+	struct ast *exists = scope_find_symbol(scope, var_id(var));
+	if (exists) {
+		semantic_error(scope->fctx, var, "var redefined");
+		semantic_info(scope->fctx, exists, "previously here");
+		return -1;
+	}
+
+	create_var(scope, var_id(var), var);
+	return 0;
+}
+
+int scope_add_proc(struct scope *scope, struct ast *proc)
+{
+	assert(proc->k == AST_PROC_DEF);
+	struct ast *exists = file_scope_find_symbol(scope, proc_id(proc));
+	if (exists) {
+		semantic_error(scope->fctx, proc, "proc redefined");
+		semantic_info(scope->fctx, exists, "previously here");
+		return -1;
+	}
+
+	/* always add to scope, do resolve checking later */
+	create_proc(scope, proc_id(proc), proc);
+	return 0;
+}
+
+static struct ast *scope_find_visible(struct visible *v, char *id)
+{
+	if (!v)
+		return NULL;
+
+	foreach_visible(n, v) {
+		struct ast *node = n->node;
+		if (same_id(node->s, id))
+			return node;
+	}
+
+	return NULL;
+}
+
+struct ast *scope_find_proc(struct scope *scope, char *id)
+{
+	struct ast *n = scope_find_visible(scope->symbols, id);
+	if (!n)
+		return NULL;
+
+	if (n->k != AST_PROC_DEF)
+		return NULL;
+
+	return n;
+}
+
+struct ast *file_scope_find_proc(struct scope *scope, char *id)
+{
+	struct ast *n = file_scope_find_symbol(scope, id);
+	if (!n)
+		return NULL;
+
+	if (n->k != AST_PROC_DEF)
+		return NULL;
+
+	return n;
+}
+
+struct ast *scope_find_symbol(struct scope *scope, char *id)
+{
+	return scope_find_visible(scope->symbols, id);
+}
+
+struct ast *file_scope_find_symbol(struct scope *scope, char *id)
+{
+	if (!scope)
+		return NULL;
+
+	struct ast *found = scope_find_symbol(scope, id);
+	if (found)
+		return found;
+
+	return file_scope_find_symbol(scope->parent, id);
+}
+
+struct ast *scope_find_var(struct scope *scope, char *id)
+{
+	struct ast *n = scope_find_visible(scope->symbols, id);
+	if (!n)
+		return NULL;
+
+	if (n->k != AST_VAR_DEF)
+		return NULL;
+
+	return n;
+}
+
+struct ast *file_scope_find_var(struct scope *scope, char *id)
+{
+	if (!scope)
+		return NULL;
+
+	struct ast *found = scope_find_var(scope, id);
+	if (found)
+		return found;
+
+	return file_scope_find_var(scope->parent, id);
+}
+
+void scope_add_scope(struct scope *parent, struct scope *child)
+{
+	assert(parent);
+	assert(child);
+
+	child->fctx = parent->fctx;
+	child->parent = parent;
+	child->next = parent->children;
+	parent->children = child;
+}