1 files changed, 51 insertions, 0 deletions
diff --git a/scope.c b/scope.c
new file mode 100644
index 0000000..cc7d7db
--- /dev/null
+++ b/scope.c
@@ -0,0 +1,51 @@
+static bool add_ident_decls(Block *b, Declaration *d) {
+	bool ret = true;
+	arr_foreach(d->idents, Identifier, ident) {
+		IdentDecl **decls = &(*ident)->decls;
+		if (arr_len(*decls)) {
+			/* check that it hasn't been declared in this block */
+			IdentDecl *prev = arr_last(*decls);
+			if (prev->scope == b) {
+				err_print(d->where, "Re-declaration of identifier in the same block.");
+				info_print(prev->decl->where, "Previous declaration was here.");
+				ret = false;
+				continue;
+			}
+		}
+		ident_add_decl(*ident, d, b);
+	}
+	return ret;
+}
+
+static void remove_ident_decls(Block *b, Declaration *d) {
+	arr_foreach(d->idents, Identifier, ident) {
+		IdentTree *id_info = *ident;
+	    IdentDecl **decls = &id_info->decls;
+		IdentDecl *last_decl = arr_last(*decls);
+		if (last_decl && last_decl->scope == b) {
+			arr_remove_last(decls); /* remove that declaration */
+		}
+	}
+}
+
+/* pass NULL for block for global scope */
+static bool block_enter(Block *b, Statement *stmts) {
+	bool ret = true;
+	arr_foreach(stmts, Statement, stmt) {
+		if (stmt->kind == STMT_DECL) {
+			Declaration *decl = &stmt->decl;
+			if (!add_ident_decls(b, decl))
+				ret = false;
+		}
+	}
+	return ret;
+}
+
+static void block_exit(Block *b, Statement *stmts) {
+	arr_foreach(stmts, Statement, stmt) {
+		if (stmt->kind == STMT_DECL) {
+			Declaration *decl = &stmt->decl;
+			remove_ident_decls(b, decl);
+		}
+	}
+}