initial commit

+ Lots of code copied from ek, so didn't have to start from scratch, but
  might mean there are some quirks here and there that made sense in ek
  but not necessarily here.

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;
+}