corelang/parse_decl.c

function Token *
parse__get_name(Parser *p){
  Token *name = token_next(p);
  token_next(p);
  token_next(p);
  return name;
}

function void 
parse_note_list(Parser *ctx, AST_Node *parent) {
  if(token_match(ctx, TK_OpenParen)) {
    do {
      Token *name = token_expect(ctx, TK_Identifier);
      AST_Node *current = ast_note(ctx, name, name->intern_val, 0);
      ast_node_push_note(parent, current);
      parse_note_list(ctx, current);
      if(token_match(ctx, TK_Assign)) {
        current->expr = parse_expr(ctx);
      }
    } while(token_match(ctx, TK_Comma));
    token_expect(ctx, TK_CloseParen);
  }
}

function void 
parse__notes(Parser *ctx, AST_Node *result) {
  while(token_match(ctx, TK_At)) {
    Token *name = token_expect(ctx, TK_Identifier);
    AST_Node *current = ast_note(ctx, name, name->intern_val, 0);
    ast_node_push_note(result, current);
    parse_note_list(ctx, current);
    if(token_match(ctx, TK_Assign)) {
      current->expr = parse_expr(ctx);
    }
  }
}

function AST_Node
parse_notes(Parser *p){
  AST_Node result = {};
  parse__notes(p, &result);
  return result;
}

function AST_Node *
parse_enum(Parser *p, Token *name){
  AST_Node *result = 0;
  if(token_expect(p, TK_OpenBrace)){
    result = ast_enum(p, name, name->intern_val);
    do{
      AST_Node notes = parse_notes(p);
      Token *token = token_match(p, TK_Identifier);
      if(token){
        Expr *expr = 0;
        if(token_match(p, TK_Assign)){
          expr = parse_expr(p);
        }
        
        AST_Node *child = ast_enum_child(p, token, token->intern_val, expr);
        ast_node_pass_note_list(child,&notes);
        ast_node_push_child(result, child);
      }
      else{
        break;
      }
    } while(token_match(p, TK_Comma));
    token_expect(p, TK_CloseBrace);
  }
  return result;
}

function AST_Node *
parse_variable(Parser *p, Token *name){
  AST_Node *result = 0;
  Token *type_token = token_expect(p, TK_Identifier);
  if(type_token){
    AST_Node *type = symbol_require_type(p, type_token);
    Token *star;
    while((star  = token_match(p, TK_Mul))){
      type = ast_type_pointer(p, star, type);
    }
    while((star  = token_match(p, TK_OpenBracket))){
      Expr *expr = parse_expr(p);
      type = ast_type_array(p, star, type, expr);
      token_expect(p, TK_CloseBracket);
    }
    Expr *expr = 0;
    if(token_match(p, TK_Assign)){
      expr = parse_expr(p);
    }
    result = ast_variable(p, name, name->intern_val, type, expr);
  }
  return result;
}

function AST_Node *
parse_struct(Parser *p, Token *name, AST_Kind kind, B32 is_global){
  AST_Node *result = 0;
  if(token_expect(p, TK_OpenBrace)){
    result = ast_struct(p, name, name?name->intern_val:(Intern_String){}, kind);
    if(is_global) symbol_register(p, result);
    
    for(;;){
      AST_Node notes = parse_notes(p);
      AST_Node *mem = 0;
      Token *mem_name = token_match(p, TK_Identifier);
      if(mem_name){
        if(token_expect(p, TK_Colon)){
          
          if(token_match_keyword(p, keyword_struct)){
            mem = parse_struct(p, mem_name, AK_Struct, false);
          }
          else if(token_match_keyword(p, keyword_union)){
            mem = parse_struct(p, mem_name, AK_Union, false);
          }
          //else if(token_match_keyword(p, keyword_enum)){
          //mem = parse_enum(p, mem_name);
          //}
          else if(token_is(p, TK_Identifier)){
            mem = parse_variable(p, mem_name);
            token_expect(p, TK_Semicolon);
          }
          else parser_push_error(p, mem_name, "Unrecognized token while parsing struct");
          
          if(mem){
            ast_node_pass_note_list(mem, &notes);
            ast_node_push_child(result, mem);
          }
          
        }
        else{
          break;
        }
      }
      else if(token_match_keyword(p, keyword_union) &&
              token_match(p, TK_Colon)){
        mem = parse_struct(p, 0, AK_Union, false);
        ast_node_pass_note_list(mem, &notes);
        ast_node_push_child(result, mem);
      }
      else if(token_match_keyword(p, keyword_struct) &&
              token_match(p, TK_Colon)){
        mem = parse_struct(p, 0, AK_Struct, false);
        ast_node_pass_note_list(mem, &notes);
        ast_node_push_child(result, mem);
      }
      else if(token_expect(p, TK_CloseBrace)){
        break;
      }
      else{
        break;
      }
    }
  }
  return result;
}

function AST_Node *
parse_typedef(Parser *p, Token *name){
  Token *type_token = token_expect(p, TK_Identifier);
  AST_Node *type = symbol_require_type(p, type_token);
  AST_Node *result = ast_typedef(p, name, name->intern_val, type);
  token_expect(p, TK_Semicolon);
  return result;
}

function AST_Node_List *
parse(Parser *p){
  AST_Node_List *result = ast_node_new(p, AK_List, token_get(p), intern_empty);
  
  for(;;){
    AST_Node *node = 0;
    AST_Node notes = parse_notes(p);
    
    if(token_is(p, TK_End)){
      break;
    }
    else if(token_is(p, TK_Error)){
      break;
    }
    else if(token_is(p, TK_Identifier) &&  // Peeking to be more error averse
            token_peek_is(p, 1, TK_Colon)){
      if(token_peek_is_keyword(p, 2, keyword_struct)){
        node = parse_struct(p, parse__get_name(p), AK_Struct, true);
        symbol_register(p, node);
      }
      else if(token_peek_is_keyword(p, 2, keyword_union)){
        node = parse_struct(p, parse__get_name(p), AK_Union, true);
        symbol_register(p, node);
      }
      else if(token_peek_is_keyword(p, 2, keyword_enum)){
        node = parse_enum(p, parse__get_name(p));
        symbol_register(p, node);
      }
      else if(token_peek_is_keyword(p, 2, keyword_typedef)){
        node = parse_typedef(p, parse__get_name(p));
        symbol_register(p, node);
      }
      else{
        token_next(p);
      }
    }
    else{
      token_next(p);
    }
    
    
    if(node){
      ast_node_pass_note_list(node, &notes);
      ast_node_push_child(result, node);
    }
    else if(notes.first_note != 0){
      parser_push_error(p, token_get(p), "Warning: notes got lost");
    }
  }
  
  return result;
}