[PATCH olang v1 5/5] semantics: add scope to all nodes

[Carlos Maniero <carlos@maniero.me>]

Instead of manually adding scopes to nodes as needed, now the scope is a
base attribute. This makes the implementation simpler and consistent so
we no longer need to think if some node kind requires or not the scope.

Signed-off-by: Carlos Maniero <carlos@maniero.me>
---
 src/ast.h            |  5 +----
 src/codegen_x86_64.c | 15 ++++++++-------
 src/type_checker.c   | 12 +++++-------
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/src/ast.h b/src/ast.h
index 7c5e9af..abc12e2 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -30,6 +30,7 @@
     {                                                                          \
         ast_node_kind_t kind;                                                  \
         token_loc_t loc;                                                       \
+        scope_t *scope;                                                        \
     }
 
 /**
@@ -88,7 +89,6 @@ typedef struct ast_fn_definition
     type_t *return_type;
     bool _extern;
     ast_node_t *block;
-    scope_t *scope;
 } ast_fn_definition_t;
 
 typedef struct ast_fn_call
@@ -96,7 +96,6 @@ typedef struct ast_fn_call
     AST_NODE_HEAD;
     string_view_t id;
     list_t *args;
-    scope_t *scope;
 } ast_fn_call_t;
 
 typedef struct ast_var_definition
@@ -105,7 +104,6 @@ typedef struct ast_var_definition
     string_view_t id;
     type_t *type;
     ast_node_t *value;
-    scope_t *scope;
 } ast_var_definition_t;
 
 typedef enum
@@ -127,7 +125,6 @@ typedef struct ast_ref
 {
     AST_NODE_HEAD;
     string_view_t id;
-    scope_t *scope;
 } ast_ref_t;
 
 typedef enum ast_binary_op_kind
diff --git a/src/codegen_x86_64.c b/src/codegen_x86_64.c
index 9006250..616fa2b 100644
--- a/src/codegen_x86_64.c
+++ b/src/codegen_x86_64.c
@@ -143,7 +143,7 @@ codegen_x86_64_emit_expression(codegen_x86_64_t *codegen, ast_node_t *expr_node)
         case AST_NODE_REF: {
             ast_ref_t ref = expr_node->as_ref;
 
-            symbol_t *symbol = scope_lookup(ref.scope, ref.id);
+            symbol_t *symbol = scope_lookup(expr_node->scope, ref.id);
             assert(symbol);
 
             size_t offset = codegen_x86_64_get_stack_offset(codegen, symbol);
@@ -159,7 +159,7 @@ codegen_x86_64_emit_expression(codegen_x86_64_t *codegen, ast_node_t *expr_node)
         case AST_NODE_FN_CALL: {
             ast_fn_call_t fn_call = expr_node->as_fn_call;
 
-            symbol_t *symbol = scope_lookup(fn_call.scope, fn_call.id);
+            symbol_t *symbol = scope_lookup(expr_node->scope, fn_call.id);
             assert(symbol);
 
             size_t i = 0;
@@ -597,7 +597,7 @@ codegen_x86_64_emit_expression(codegen_x86_64_t *codegen, ast_node_t *expr_node)
                     switch (bin_op.lhs->kind) {
                         case AST_NODE_REF: {
                             ast_ref_t ref = bin_op.lhs->as_ref;
-                            scope_t *scope = ref.scope;
+                            scope_t *scope = bin_op.lhs->scope;
 
                             symbol_t *symbol = scope_lookup(scope, ref.id);
                             assert(symbol);
@@ -668,7 +668,8 @@ codegen_x86_64_emit_expression(codegen_x86_64_t *codegen, ast_node_t *expr_node)
 
                     ast_ref_t ref = unary_op.operand->as_ref;
 
-                    symbol_t *symbol = scope_lookup(ref.scope, ref.id);
+                    symbol_t *symbol =
+                        scope_lookup(unary_op.operand->scope, ref.id);
                     assert(symbol);
 
                     size_t offset =
@@ -722,7 +723,7 @@ codegen_x86_64_emit_block(codegen_x86_64_t *codegen, ast_block_t *block)
 
             case AST_NODE_VAR_DEF: {
                 ast_var_definition_t var_def = node->as_var_def;
-                scope_t *scope = var_def.scope;
+                scope_t *scope = node->scope;
 
                 symbol_t *symbol = scope_lookup(scope, var_def.id);
                 assert(symbol);
@@ -908,7 +909,7 @@ codegen_x86_64_emit_function(codegen_x86_64_t *codegen,
 
         ast_fn_param_t *param = item->value;
 
-        symbol_t *symbol = scope_lookup(fn_def->scope, param->id);
+        symbol_t *symbol = scope_lookup(fn_def->base.scope, param->id);
         assert(symbol);
 
         // FIXME: add offset according to the param size
@@ -926,7 +927,7 @@ codegen_x86_64_emit_function(codegen_x86_64_t *codegen,
         ++i;
     }
 
-    size_t local_size = calculate_fn_local_size(fn_def->scope);
+    size_t local_size = calculate_fn_local_size(fn_def->base.scope);
 
     if (local_size != 0) {
         fprintf(codegen->out, "    sub $%ld, %%rsp\n", local_size);
diff --git a/src/type_checker.c b/src/type_checker.c
index 235d711..cc87832 100644
--- a/src/type_checker.c
+++ b/src/type_checker.c
@@ -108,6 +108,8 @@ populate_scope(checker_t *checker, scope_t *scope, ast_node_t *ast)
     assert(checker);
     assert(scope);
 
+    ast->scope = scope;
+
     switch (ast->kind) {
         case AST_NODE_TRANSLATION_UNIT: {
             list_item_t *item = list_head(ast->as_translation_unit.decls);
@@ -121,7 +123,7 @@ populate_scope(checker_t *checker, scope_t *scope, ast_node_t *ast)
 
         case AST_NODE_FN_DEF: {
             ast_fn_definition_t *fn_def = &ast->as_fn_def;
-            fn_def->scope = scope_push(scope);
+            ast->scope = scope_push(scope);
 
             type_resolve(fn_def->return_type);
             symbol_t *symbol =
@@ -136,20 +138,18 @@ populate_scope(checker_t *checker, scope_t *scope, ast_node_t *ast)
                 type_resolve(param->type);
                 symbol_t *symbol =
                     symbol_new(checker->arena, param->id, param->type);
-                scope_insert(fn_def->scope, symbol);
+                scope_insert(ast->scope, symbol);
 
                 item = list_next(item);
             }
 
             if (ast->as_fn_def.block != NULL) {
-                populate_scope(checker, fn_def->scope, ast->as_fn_def.block);
+                populate_scope(checker, ast->scope, ast->as_fn_def.block);
             }
             return;
         }
 
         case AST_NODE_FN_CALL: {
-            ast->as_fn_call.scope = scope;
-
             list_item_t *item = list_head(ast->as_fn_call.args);
 
             while (item != NULL) {
@@ -223,14 +223,12 @@ populate_scope(checker_t *checker, scope_t *scope, ast_node_t *ast)
                 symbol_new(checker->arena, id, ast->as_var_def.type);
 
             scope_insert(scope, symbol);
-            ast->as_var_def.scope = scope;
 
             populate_scope(checker, scope, ast->as_var_def.value);
             return;
         }
 
         case AST_NODE_REF: {
-            ast->as_ref.scope = scope;
             return;
         }
 
-- 
2.46.1