gas: Compile variable expression with scope support

This patch adds the variable compilation and uses a scope (a stack of
map) to lookup for identities.

Today we use a vector + ref_entry structs in order to achieve the scope
implementation. The ref_entry lacks memory management, we are still no
sure who will be the owner of the pointer.

We also want to replace the scope a hashtable_t type as soon as we get
one.

Signed-off-by: Johnny Richard <johnny@johnnyrichard.com>
Co-authored-by: Carlos Maniero <carlosmaniero@gmail.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/parser.c b/src/parser.c
index 48a9125..f4829ee 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -135,10 +135,10 @@ parser_parse_factor(parser_t *parser, ast_node_t *node)
       if (!drop_expected_token(parser, TOKEN_CPAREN))
         return false;
       return true;
-    case TOKEN_NAME:
-      ast_node_init_identifier(node, token.value);
+    case TOKEN_NAME: {
       // TODO: Check node kind, today accepts only variables
-      if (scope_get(parser->scope, token.value) == NULL) {
+      ast_node_t *var_node = scope_get(parser->scope, token.value);
+      if (var_node == NULL) {
         parser_error_t error;
         error.token = token;
         sprintf(error.message, "identifier '" SVFMT "' not defined", SVARG(&token.value));
@@ -146,7 +146,10 @@ parser_parse_factor(parser_t *parser, ast_node_t *node)
         return false;
       }
 
+      ast_node_init_variable(node, &var_node->data.variable_declaration.identifier);
+
       return true;
+    }
     default: {
       parser_error_t error;
       error.token = token;