------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- P A R . C H 1 1 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2004 Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ pragma Style_Checks (All_Checks); -- Turn off subprogram body ordering check. Subprograms are in order -- by RM section rather than alphabetical with Sinfo.CN; use Sinfo.CN; separate (Par) package body Ch11 is -- Local functions, used only in this chapter function P_Exception_Handler return Node_Id; function P_Exception_Choice return Node_Id; --------------------------------- -- 11.1 Exception Declaration -- --------------------------------- -- Parsed by P_Identifier_Declaration (3.3.1) ------------------------------------------ -- 11.2 Handled Sequence Of Statements -- ------------------------------------------ -- HANDLED_SEQUENCE_OF_STATEMENTS ::= -- SEQUENCE_OF_STATEMENTS -- [exception -- EXCEPTION_HANDLER -- {EXCEPTION_HANDLER}] -- Error_Recovery : Cannot raise Error_Resync function P_Handled_Sequence_Of_Statements return Node_Id is Handled_Stmt_Seq_Node : Node_Id; begin Handled_Stmt_Seq_Node := New_Node (N_Handled_Sequence_Of_Statements, Token_Ptr); Set_Statements (Handled_Stmt_Seq_Node, P_Sequence_Of_Statements (SS_Extm_Sreq)); if Token = Tok_Exception then Scan; -- past EXCEPTION Set_Exception_Handlers (Handled_Stmt_Seq_Node, Parse_Exception_Handlers); end if; return Handled_Stmt_Seq_Node; end P_Handled_Sequence_Of_Statements; ----------------------------- -- 11.2 Exception Handler -- ----------------------------- -- EXCEPTION_HANDLER ::= -- when [CHOICE_PARAMETER_SPECIFICATION :] -- EXCEPTION_CHOICE {| EXCEPTION_CHOICE} => -- SEQUENCE_OF_STATEMENTS -- CHOICE_PARAMETER_SPECIFICATION ::= DEFINING_IDENTIFIER -- Error recovery: cannot raise Error_Resync function P_Exception_Handler return Node_Id is Scan_State : Saved_Scan_State; Handler_Node : Node_Id; Choice_Param_Node : Node_Id; begin Handler_Node := New_Node (N_Exception_Handler, Token_Ptr); T_When; -- Test for possible choice parameter present if Token = Tok_Identifier then Choice_Param_Node := Token_Node; Save_Scan_State (Scan_State); -- at identifier Scan; -- past identifier if Token = Tok_Colon then if Ada_Version = Ada_83 then Error_Msg_SP ("(Ada 83) choice parameter not allowed!"); end if; Scan; -- past : Change_Identifier_To_Defining_Identifier (Choice_Param_Node); Set_Choice_Parameter (Handler_Node, Choice_Param_Node); elsif Token = Tok_Others then Error_Msg_AP ("missing "":"""); Change_Identifier_To_Defining_Identifier (Choice_Param_Node); Set_Choice_Parameter (Handler_Node, Choice_Param_Node); else Restore_Scan_State (Scan_State); -- to identifier end if; end if; -- Loop through exception choices Set_Exception_Choices (Handler_Node, New_List); loop Append (P_Exception_Choice, Exception_Choices (Handler_Node)); exit when Token /= Tok_Vertical_Bar; Scan; -- past vertical bar end loop; TF_Arrow; Set_Statements (Handler_Node, P_Sequence_Of_Statements (SS_Sreq_Whtm)); return Handler_Node; end P_Exception_Handler; ------------------------------------------ -- 11.2 Choice Parameter Specification -- ------------------------------------------ -- Parsed by P_Exception_Handler (11.2) ---------------------------- -- 11.2 Exception Choice -- ---------------------------- -- EXCEPTION_CHOICE ::= exception_NAME | others -- Error recovery: cannot raise Error_Resync. If an error occurs, then the -- scan pointer is advanced to the next arrow or vertical bar or semicolon. function P_Exception_Choice return Node_Id is begin if Token = Tok_Others then Scan; -- past OTHERS return New_Node (N_Others_Choice, Prev_Token_Ptr); else return P_Name; -- exception name end if; exception when Error_Resync => Resync_Choice; return Error; end P_Exception_Choice; --------------------------- -- 11.3 Raise Statement -- --------------------------- -- RAISE_STATEMENT ::= raise [exception_NAME]; -- The caller has verified that the initial token is RAISE -- Error recovery: can raise Error_Resync function P_Raise_Statement return Node_Id is Raise_Node : Node_Id; begin Raise_Node := New_Node (N_Raise_Statement, Token_Ptr); Scan; -- past RAISE if Token /= Tok_Semicolon then Set_Name (Raise_Node, P_Name); end if; TF_Semicolon; return Raise_Node; end P_Raise_Statement; ------------------------------ -- Parse_Exception_Handlers -- ------------------------------ -- This routine scans out a list of exception handlers appearing in a -- construct as: -- exception -- EXCEPTION_HANDLER {EXCEPTION_HANDLER} -- The caller has scanned out the EXCEPTION keyword -- Control returns after scanning the last exception handler, presumably -- at the keyword END, but this is not checked in this routine. -- Error recovery: cannot raise Error_Resync function Parse_Exception_Handlers return List_Id is Handler : Node_Id; Handlers_List : List_Id; begin Handlers_List := New_List; P_Pragmas_Opt (Handlers_List); if Token = Tok_End then Error_Msg_SC ("must have at least one exception handler!"); else loop Handler := P_Exception_Handler; Append (Handler, Handlers_List); -- Note: no need to check for pragmas here. Although the -- syntax officially allows them in this position, they -- will have been swallowed up as part of the statement -- sequence of the handler we just scanned out. exit when Token /= Tok_When; end loop; end if; return Handlers_List; end Parse_Exception_Handlers; end Ch11;