parser: Registry identifiers on scope

We are parsing variables/functions and checking if they are defined on
scope. Otherwise we fail the parsing with a nice message.

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

8 files changed, 58 insertions, 12 deletions

diff --git a/src/ast.c b/src/ast.c
index d3e9a28..49d772a 100644
--- a/src/ast.c
+++ b/src/ast.c
@@ -108,6 +108,13 @@ ast_node_init_variable_declaration(ast_node_t *node, string_view_t variable_name
 }
 
 void
+ast_node_init_variable(ast_node_t *node, ast_identifier_t *identifier)
+{
+  node->kind = AST_VARIABLE;
+  node->data = (ast_node_data_t){ .variable_ex = { .identifier = identifier } };
+}
+
+void
 ast_node_init_identifier(ast_node_t *node, string_view_t name)
 {
   node->kind = AST_IDENTIFIER;
diff --git a/src/ast.h b/src/ast.h
index e25f1bb..4fd1d1d 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -37,6 +37,11 @@ typedef struct ast_identifier_t
   string_view_t name;
 } ast_identifier_t;
 
+typedef struct ast_variable_t
+{
+  ast_identifier_t *identifier;
+} ast_variable_t;
+
 typedef struct ast_function_declaration_t
 {
   ast_identifier_t identifier;
@@ -91,6 +96,7 @@ typedef enum
   AST_RETURN_STMT,
   AST_UNKOWN_NODE,
   AST_VARIABLE_DECLARATION,
+  AST_VARIABLE
 } ast_node_kind_t;
 
 typedef union
@@ -99,8 +105,9 @@ typedef union
   ast_function_declaration_t function;
   ast_literal_t literal;
   ast_return_stmt_t return_stmt;
-  ast_variable_declaration_t variable;
+  ast_variable_declaration_t variable; // FIXME: Rename to variable_declaration
   ast_identifier_t identifier;
+  ast_variable_t variable_ex; // FIXME: Rename to variable
 } ast_node_data_t;
 
 typedef struct ast_node_t
@@ -127,5 +134,7 @@ ast_node_init_variable_declaration(ast_node_t *node, string_view_t variable_name
 // FIXME: use the naming convention
 void
 ast_literal_integer_create(ast_node_t *node, uint32_t number);
+void
+ast_node_init_variable(ast_node_t *node, ast_identifier_t *identifier);
 
 #endif /* AST_H */
diff --git a/src/gas_assembly_generator.c b/src/gas_assembly_generator.c
index ea76c5f..f09b60d 100644
--- a/src/gas_assembly_generator.c
+++ b/src/gas_assembly_generator.c
@@ -61,6 +61,9 @@ gas_assembly_generator_compile(gas_assembly_generator_t *gen, ast_node_t *ast)
     case AST_VARIABLE_DECLARATION:
       assert(false && "TODO: ast variable declaration not implemented yet");
       break;
+    case AST_VARIABLE:
+      assert(false && "TODO: ast variable not implemented yet");
+      break;
     case AST_UNKOWN_NODE:
       assert(false && "unreachable");
   }
diff --git a/src/parser.c b/src/parser.c
index 6b954c2..469fa99 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -24,14 +24,16 @@
 #include "ast.h"
 #include "lexer.h"
 #include "parser.h"
+#include "scope.h"
 #include "vector.h"
 
 void
-parser_init(parser_t *parser, lexer_t *lexer)
+parser_init(parser_t *parser, lexer_t *lexer, scope_t *scope)
 {
   assert(parser && "parser must be defined");
   assert(lexer && "lexer must be defined");
   parser->lexer = lexer;
+  parser->scope = scope;
   parser->errors_len = 0;
 }
 
@@ -134,8 +136,16 @@ parser_parse_factor(parser_t *parser, ast_node_t *node)
         return false;
       return true;
     case TOKEN_NAME:
-      /// FIXME: Check if the identifier is defined
       ast_node_init_identifier(node, token.value);
+      // TODO: Check node kind, today accepts only variables
+      if (scope_get(parser->scope, token.value) == NULL) {
+        parser_error_t error;
+        error.token = token;
+        sprintf(error.message, "identifier '" SVFMT "' not defined", SVARG(&token.value));
+        parser->errors[parser->errors_len++] = error;
+        return false;
+      }
+
       return true;
     default: {
       parser_error_t error;
@@ -143,7 +153,7 @@ parser_parse_factor(parser_t *parser, ast_node_t *node)
       sprintf(error.message, "unexpected '%s (" SVFMT ")' token", token_kind_to_str(token.kind), SVARG(&token.value));
       parser->errors[parser->errors_len++] = error;
       return false;
-   }
+    }
   }
 }
 
@@ -247,6 +257,7 @@ parser_parse_variable_definition(parser_t *parser, string_view_t variable_name,
   }
 
   ast_node_init_variable_declaration(node, variable_name, type, expression);
+  scope_push(parser->scope, &node->data.variable.identifier, node);
 
   return true;
 }
@@ -333,11 +344,17 @@ parser_parse_function_declaration(parser_t *parser, ast_node_t *node)
     return false;
 
   vector_t *body = vector_new();
+  ast_node_init_function_declaration(node, func_name_token.value, return_type, body);
+  scope_push(parser->scope, &node->data.function.identifier, node);
+
+  scope_enter(parser->scope);
 
-  if (!parser_parse_block_declarations(parser, body))
+  if (!parser_parse_block_declarations(parser, body)) {
+    scope_leave(parser->scope);
     return false;
+  }
 
-  ast_node_init_function_declaration(node, func_name_token.value, return_type, body);
+  scope_leave(parser->scope);
 
   return true;
 }
diff --git a/src/parser.h b/src/parser.h
index bdf0c5a..d3e1431 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -19,6 +19,7 @@
 
 #include "ast.h"
 #include "lexer.h"
+#include "scope.h"
 #include "string_view.h"
 
 typedef struct parser_error_t
@@ -30,13 +31,14 @@ typedef struct parser_error_t
 typedef struct parser_t
 {
   lexer_t *lexer;
+  scope_t *scope;
   int errors_len;
   // FIXME: replace with vector
   parser_error_t errors[1];
 } parser_t;
 
 void
-parser_init(parser_t *parser, lexer_t *lexer);
+parser_init(parser_t *parser, lexer_t *lexer, scope_t *scope);
 
 bool
 parser_parse_function_declaration(parser_t *parser, ast_node_t *node);
diff --git a/src/pipac.c b/src/pipac.c
index b31b8b5..2041218 100644
--- a/src/pipac.c
+++ b/src/pipac.c
@@ -22,6 +22,7 @@
 #include "gas_assembly_generator.h"
 #include "lexer.h"
 #include "parser.h"
+#include "scope.h"
 #include "string_view.h"
 
 static void
@@ -62,8 +63,9 @@ main(int argc, char **argv)
   lexer_t lexer;
   lexer_init(&lexer, filepath);
 
+  scope_t *scope = scope_new();
   parser_t parser;
-  parser_init(&parser, &lexer);
+  parser_init(&parser, &lexer, scope);
 
   ast_node_t *func = ast_node_new();
 
@@ -74,6 +76,7 @@ main(int argc, char **argv)
 
   generate_gas_x86_64_linux(func);
 
+  scope_destroy(scope);
   ast_node_destroy(func);
   return EXIT_SUCCESS;
 }
diff --git a/src/scope.c b/src/scope.c
index 5b696ad..662e59c 100644
--- a/src/scope.c
+++ b/src/scope.c
@@ -54,7 +54,7 @@ scope_new(void)
 void
 scope_destroy(scope_t *scope)
 {
-  if (scope->stack->size) {
+  if (scope->stack->size != 1) {
     fprintf(stderr,
             "Stack not cleaned before destroying. This may lead to memory leaks.\n"
             "Please make sure to call the leave function before destroying it.");
@@ -97,7 +97,7 @@ scope_leave(scope_t *scope)
 }
 
 ast_node_t *
-scope_get(scope_t *scope, ast_identifier_t *identifier)
+scope_get(scope_t *scope, string_view_t name)
 {
   for (size_t i = scope->stack->size; i > 0; i--) {
     vector_t *current_level = vector_at(scope->stack, i - 1);
@@ -105,7 +105,7 @@ scope_get(scope_t *scope, ast_identifier_t *identifier)
     for (size_t j = 0; j < current_level->size; j++) {
       scope_item_t *item = vector_at(current_level, j);
 
-      if (string_view_eq(identifier->name, item->identifier->name)) {
+      if (string_view_eq(name, item->identifier->name)) {
         return item->node;
       }
     }
diff --git a/src/scope.h b/src/scope.h
index c221703..2636990 100644
--- a/src/scope.h
+++ b/src/scope.h
@@ -14,6 +14,9 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
+#ifndef SCOPE_H
+#define SCOPE_H
+
 #include "ast.h"
 #include "string_view.h"
 #include "vector.h"
@@ -41,6 +44,8 @@ void
 scope_leave(scope_t *scope);
 
 ast_node_t *
-scope_get(scope_t *scope, ast_identifier_t *identifier);
+scope_get(scope_t *scope, string_view_t name);
 void
 scope_push(scope_t *scope, ast_identifier_t *identifier, ast_node_t *node);
+
+#endif /* SCOPE_H */