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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- P A R . C H 5 --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING3. If not, go to --
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-- http://www.gnu.org/licenses for a complete copy of the license. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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pragma Style_Checks (All_Checks);
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-- Turn off subprogram body ordering check. Subprograms are in order
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-- by RM section rather than alphabetical
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separate (Par)
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package body Ch5 is
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-- Local functions, used only in this chapter
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function P_Case_Statement return Node_Id;
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function P_Case_Statement_Alternative return Node_Id;
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function P_Condition return Node_Id;
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function P_Exit_Statement return Node_Id;
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function P_Goto_Statement return Node_Id;
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function P_If_Statement return Node_Id;
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function P_Label return Node_Id;
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function P_Loop_Parameter_Specification return Node_Id;
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function P_Null_Statement return Node_Id;
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function P_Assignment_Statement (LHS : Node_Id) return Node_Id;
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-- Parse assignment statement. On entry, the caller has scanned the left
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-- hand side (passed in as Lhs), and the colon-equal (or some symbol
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-- taken to be an error equivalent such as equal).
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function P_Begin_Statement (Block_Name : Node_Id := Empty) return Node_Id;
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-- Parse begin-end statement. If Block_Name is non-Empty on entry, it is
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-- the N_Identifier node for the label on the block. If Block_Name is
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-- Empty on entry (the default), then the block statement is unlabeled.
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function P_Declare_Statement (Block_Name : Node_Id := Empty) return Node_Id;
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-- Parse declare block. If Block_Name is non-Empty on entry, it is
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-- the N_Identifier node for the label on the block. If Block_Name is
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-- Empty on entry (the default), then the block statement is unlabeled.
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function P_For_Statement (Loop_Name : Node_Id := Empty) return Node_Id;
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-- Parse for statement. If Loop_Name is non-Empty on entry, it is
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-- the N_Identifier node for the label on the loop. If Loop_Name is
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-- Empty on entry (the default), then the for statement is unlabeled.
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function P_Loop_Statement (Loop_Name : Node_Id := Empty) return Node_Id;
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-- Parse loop statement. If Loop_Name is non-Empty on entry, it is
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-- the N_Identifier node for the label on the loop. If Loop_Name is
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-- Empty on entry (the default), then the loop statement is unlabeled.
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function P_While_Statement (Loop_Name : Node_Id := Empty) return Node_Id;
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-- Parse while statement. If Loop_Name is non-Empty on entry, it is
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-- the N_Identifier node for the label on the loop. If Loop_Name is
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-- Empty on entry (the default), then the while statement is unlabeled.
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function Set_Loop_Block_Name (L : Character) return Name_Id;
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-- Given a letter 'L' for a loop or 'B' for a block, returns a name
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-- of the form L_nn or B_nn where nn is a serial number obtained by
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-- incrementing the variable Loop_Block_Count.
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procedure Then_Scan;
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-- Scan past THEN token, testing for illegal junk after it
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---------------------------------
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-- 5.1 Sequence of Statements --
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---------------------------------
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-- SEQUENCE_OF_STATEMENTS ::= STATEMENT {STATEMENT}
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-- STATEMENT ::=
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-- {LABEL} SIMPLE_STATEMENT | {LABEL} COMPOUND_STATEMENT
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-- SIMPLE_STATEMENT ::= NULL_STATEMENT
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-- | ASSIGNMENT_STATEMENT | EXIT_STATEMENT
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-- | GOTO_STATEMENT | PROCEDURE_CALL_STATEMENT
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-- | RETURN_STATEMENT | ENTRY_CALL_STATEMENT
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-- | REQUEUE_STATEMENT | DELAY_STATEMENT
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-- | ABORT_STATEMENT | RAISE_STATEMENT
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-- | CODE_STATEMENT
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-- COMPOUND_STATEMENT ::=
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-- IF_STATEMENT | CASE_STATEMENT
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-- | LOOP_STATEMENT | BLOCK_STATEMENT
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-- | ACCEPT_STATEMENT | SELECT_STATEMENT
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-- This procedure scans a sequence of statements. The caller sets SS_Flags
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-- to indicate acceptable termination conditions for the sequence:
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-- SS_Flags.Eftm Terminate on ELSIF
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-- SS_Flags.Eltm Terminate on ELSE
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-- SS_Flags.Extm Terminate on EXCEPTION
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-- SS_Flags.Ortm Terminate on OR
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-- SS_Flags.Tatm Terminate on THEN ABORT (Token = ABORT on return)
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-- SS_Flags.Whtm Terminate on WHEN
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-- SS_Flags.Unco Unconditional terminate after scanning one statement
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-- In addition, the scan is always terminated by encountering END or the
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-- end of file (EOF) condition. If one of the six above terminators is
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-- encountered with the corresponding SS_Flags flag not set, then the
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-- action taken is as follows:
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-- If the keyword occurs to the left of the expected column of the end
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-- for the current sequence (as recorded in the current end context),
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-- then it is assumed to belong to an outer context, and is considered
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-- to terminate the sequence of statements.
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-- If the keyword occurs to the right of, or in the expected column of
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-- the end for the current sequence, then an error message is output,
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-- the keyword together with its associated context is skipped, and
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-- the statement scan continues until another terminator is found.
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-- Note that the first action means that control can return to the caller
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-- with Token set to a terminator other than one of those specified by the
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-- SS parameter. The caller should treat such a case as equivalent to END.
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-- In addition, the flag SS_Flags.Sreq is set to True to indicate that at
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-- least one real statement (other than a pragma) is required in the
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-- statement sequence. During the processing of the sequence, this
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-- flag is manipulated to indicate the current status of the requirement
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-- for a statement. For example, it is turned off by the occurrence of a
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-- statement, and back on by a label (which requires a following statement)
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-- Error recovery: cannot raise Error_Resync. If an error occurs during
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-- parsing a statement, then the scan pointer is advanced past the next
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-- semicolon and the parse continues.
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function P_Sequence_Of_Statements (SS_Flags : SS_Rec) return List_Id is
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Statement_Required : Boolean;
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-- This flag indicates if a subsequent statement (other than a pragma)
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-- is required. It is initialized from the Sreq flag, and modified as
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-- statements are scanned (a statement turns it off, and a label turns
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-- it back on again since a statement must follow a label).
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Declaration_Found : Boolean := False;
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-- This flag is set True if a declaration is encountered, so that the
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-- error message about declarations in the statement part is only
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-- given once for a given sequence of statements.
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Scan_State_Label : Saved_Scan_State;
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Scan_State : Saved_Scan_State;
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Statement_List : List_Id;
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Block_Label : Name_Id;
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Id_Node : Node_Id;
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Name_Node : Node_Id;
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procedure Junk_Declaration;
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-- Procedure called to handle error of declaration encountered in
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-- statement sequence.
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procedure Test_Statement_Required;
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-- Flag error if Statement_Required flag set
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----------------------
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-- Junk_Declaration --
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----------------------
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procedure Junk_Declaration is
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begin
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if (not Declaration_Found) or All_Errors_Mode then
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Error_Msg_SC -- CODEFIX
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("declarations must come before BEGIN");
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Declaration_Found := True;
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end if;
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Skip_Declaration (Statement_List);
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end Junk_Declaration;
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-----------------------------
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-- Test_Statement_Required --
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-----------------------------
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procedure Test_Statement_Required is
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begin
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if Statement_Required then
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Error_Msg_BC ("statement expected");
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end if;
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end Test_Statement_Required;
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-- Start of processing for P_Sequence_Of_Statements
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begin
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Statement_List := New_List;
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Statement_Required := SS_Flags.Sreq;
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loop
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Ignore (Tok_Semicolon);
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begin
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if Style_Check then
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Style.Check_Indentation;
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end if;
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-- Deal with reserved identifier (in assignment or call)
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if Is_Reserved_Identifier then
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Save_Scan_State (Scan_State); -- at possible bad identifier
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Scan; -- and scan past it
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-- We have an reserved word which is spelled in identifier
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-- style, so the question is whether it really is intended
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-- to be an identifier.
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if
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-- If followed by a semicolon, then it is an identifier,
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-- with the exception of the cases tested for below.
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(Token = Tok_Semicolon
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and then Prev_Token /= Tok_Return
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and then Prev_Token /= Tok_Null
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and then Prev_Token /= Tok_Raise
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and then Prev_Token /= Tok_End
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and then Prev_Token /= Tok_Exit)
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-- If followed by colon, colon-equal, or dot, then we
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-- definitely have an identifier (could not be reserved)
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or else Token = Tok_Colon
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or else Token = Tok_Colon_Equal
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or else Token = Tok_Dot
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-- Left paren means we have an identifier except for those
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-- reserved words that can legitimately be followed by a
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-- left paren.
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or else
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(Token = Tok_Left_Paren
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and then Prev_Token /= Tok_Case
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and then Prev_Token /= Tok_Delay
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and then Prev_Token /= Tok_If
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and then Prev_Token /= Tok_Elsif
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and then Prev_Token /= Tok_Return
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and then Prev_Token /= Tok_When
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and then Prev_Token /= Tok_While
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and then Prev_Token /= Tok_Separate)
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then
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-- Here we have an apparent reserved identifier and the
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-- token past it is appropriate to this usage (and would
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-- be a definite error if this is not an identifier). What
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-- we do is to use P_Identifier to fix up the identifier,
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-- and then fall into the normal processing.
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Restore_Scan_State (Scan_State); -- back to the ID
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Scan_Reserved_Identifier (Force_Msg => False);
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-- Not a reserved identifier after all (or at least we can't
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-- be sure that it is), so reset the scan and continue.
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else
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Restore_Scan_State (Scan_State); -- back to the reserved word
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end if;
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end if;
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-- Now look to see what kind of statement we have
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case Token is
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-- Case of end or EOF
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when Tok_End | Tok_EOF =>
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-- These tokens always terminate the statement sequence
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Test_Statement_Required;
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exit;
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-- Case of ELSIF
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when Tok_Elsif =>
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-- Terminate if Eftm set or if the ELSIF is to the left
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-- of the expected column of the end for this sequence
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if SS_Flags.Eftm
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or else Start_Column < Scope.Table (Scope.Last).Ecol
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then
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Test_Statement_Required;
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exit;
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-- Otherwise complain and skip past ELSIF Condition then
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else
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Error_Msg_SC ("ELSIF not allowed here");
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Scan; -- past ELSIF
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Discard_Junk_Node (P_Expression_No_Right_Paren);
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Then_Scan;
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Statement_Required := False;
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end if;
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-- Case of ELSE
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when Tok_Else =>
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-- Terminate if Eltm set or if the else is to the left
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-- of the expected column of the end for this sequence
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if SS_Flags.Eltm
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or else Start_Column < Scope.Table (Scope.Last).Ecol
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then
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Test_Statement_Required;
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exit;
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-- Otherwise complain and skip past else
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else
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Error_Msg_SC ("ELSE not allowed here");
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Scan; -- past ELSE
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Statement_Required := False;
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end if;
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-- Case of exception
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when Tok_Exception =>
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Test_Statement_Required;
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-- If Extm not set and the exception is not to the left
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-- of the expected column of the end for this sequence, then
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-- we assume it belongs to the current sequence, even though
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-- it is not permitted.
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if not SS_Flags.Extm and then
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Start_Column >= Scope.Table (Scope.Last).Ecol
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then
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Error_Msg_SC ("exception handler not permitted here");
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Scan; -- past EXCEPTION
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Discard_Junk_List (Parse_Exception_Handlers);
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end if;
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349 |
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-- Always return, in the case where we scanned out handlers
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351 |
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-- that we did not expect, Parse_Exception_Handlers returned
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-- with Token being either end or EOF, so we are OK
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exit;
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-- Case of OR
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when Tok_Or =>
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-- Terminate if Ortm set or if the or is to the left
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|
|
-- of the expected column of the end for this sequence
|
362 |
|
|
|
363 |
|
|
if SS_Flags.Ortm
|
364 |
|
|
or else Start_Column < Scope.Table (Scope.Last).Ecol
|
365 |
|
|
then
|
366 |
|
|
Test_Statement_Required;
|
367 |
|
|
exit;
|
368 |
|
|
|
369 |
|
|
-- Otherwise complain and skip past or
|
370 |
|
|
|
371 |
|
|
else
|
372 |
|
|
Error_Msg_SC ("OR not allowed here");
|
373 |
|
|
Scan; -- past or
|
374 |
|
|
Statement_Required := False;
|
375 |
|
|
end if;
|
376 |
|
|
|
377 |
|
|
-- Case of THEN (deal also with THEN ABORT)
|
378 |
|
|
|
379 |
|
|
when Tok_Then =>
|
380 |
|
|
Save_Scan_State (Scan_State); -- at THEN
|
381 |
|
|
Scan; -- past THEN
|
382 |
|
|
|
383 |
|
|
-- Terminate if THEN ABORT allowed (ATC case)
|
384 |
|
|
|
385 |
|
|
exit when SS_Flags.Tatm and then Token = Tok_Abort;
|
386 |
|
|
|
387 |
|
|
-- Otherwise we treat THEN as some kind of mess where we
|
388 |
|
|
-- did not see the associated IF, but we pick up assuming
|
389 |
|
|
-- it had been there!
|
390 |
|
|
|
391 |
|
|
Restore_Scan_State (Scan_State); -- to THEN
|
392 |
|
|
Append_To (Statement_List, P_If_Statement);
|
393 |
|
|
Statement_Required := False;
|
394 |
|
|
|
395 |
|
|
-- Case of WHEN (error because we are not in a case)
|
396 |
|
|
|
397 |
|
|
when Tok_When | Tok_Others =>
|
398 |
|
|
|
399 |
|
|
-- Terminate if Whtm set or if the WHEN is to the left
|
400 |
|
|
-- of the expected column of the end for this sequence
|
401 |
|
|
|
402 |
|
|
if SS_Flags.Whtm
|
403 |
|
|
or else Start_Column < Scope.Table (Scope.Last).Ecol
|
404 |
|
|
then
|
405 |
|
|
Test_Statement_Required;
|
406 |
|
|
exit;
|
407 |
|
|
|
408 |
|
|
-- Otherwise complain and skip when Choice {| Choice} =>
|
409 |
|
|
|
410 |
|
|
else
|
411 |
|
|
Error_Msg_SC ("WHEN not allowed here");
|
412 |
|
|
Scan; -- past when
|
413 |
|
|
Discard_Junk_List (P_Discrete_Choice_List);
|
414 |
|
|
TF_Arrow;
|
415 |
|
|
Statement_Required := False;
|
416 |
|
|
end if;
|
417 |
|
|
|
418 |
|
|
-- Cases of statements starting with an identifier
|
419 |
|
|
|
420 |
|
|
when Tok_Identifier =>
|
421 |
|
|
Check_Bad_Layout;
|
422 |
|
|
|
423 |
|
|
-- Save scan pointers and line number in case block label
|
424 |
|
|
|
425 |
|
|
Id_Node := Token_Node;
|
426 |
|
|
Block_Label := Token_Name;
|
427 |
|
|
Save_Scan_State (Scan_State_Label); -- at possible label
|
428 |
|
|
Scan; -- past Id
|
429 |
|
|
|
430 |
|
|
-- Check for common case of assignment, since it occurs
|
431 |
|
|
-- frequently, and we want to process it efficiently.
|
432 |
|
|
|
433 |
|
|
if Token = Tok_Colon_Equal then
|
434 |
|
|
Scan; -- past the colon-equal
|
435 |
|
|
Append_To (Statement_List,
|
436 |
|
|
P_Assignment_Statement (Id_Node));
|
437 |
|
|
Statement_Required := False;
|
438 |
|
|
|
439 |
|
|
-- Check common case of procedure call, another case that
|
440 |
|
|
-- we want to speed up as much as possible.
|
441 |
|
|
|
442 |
|
|
elsif Token = Tok_Semicolon then
|
443 |
|
|
Append_To (Statement_List,
|
444 |
|
|
P_Statement_Name (Id_Node));
|
445 |
|
|
Scan; -- past semicolon
|
446 |
|
|
Statement_Required := False;
|
447 |
|
|
|
448 |
|
|
-- Check for case of "go to" in place of "goto"
|
449 |
|
|
|
450 |
|
|
elsif Token = Tok_Identifier
|
451 |
|
|
and then Block_Label = Name_Go
|
452 |
|
|
and then Token_Name = Name_To
|
453 |
|
|
then
|
454 |
|
|
Error_Msg_SP -- CODEFIX
|
455 |
|
|
("goto is one word");
|
456 |
|
|
Append_To (Statement_List, P_Goto_Statement);
|
457 |
|
|
Statement_Required := False;
|
458 |
|
|
|
459 |
|
|
-- Check common case of = used instead of :=, just so we
|
460 |
|
|
-- give a better error message for this special misuse.
|
461 |
|
|
|
462 |
|
|
elsif Token = Tok_Equal then
|
463 |
|
|
T_Colon_Equal; -- give := expected message
|
464 |
|
|
Append_To (Statement_List,
|
465 |
|
|
P_Assignment_Statement (Id_Node));
|
466 |
|
|
Statement_Required := False;
|
467 |
|
|
|
468 |
|
|
-- Check case of loop label or block label
|
469 |
|
|
|
470 |
|
|
elsif Token = Tok_Colon
|
471 |
|
|
or else (Token in Token_Class_Labeled_Stmt
|
472 |
|
|
and then not Token_Is_At_Start_Of_Line)
|
473 |
|
|
then
|
474 |
|
|
T_Colon; -- past colon (if there, or msg for missing one)
|
475 |
|
|
|
476 |
|
|
-- Test for more than one label
|
477 |
|
|
|
478 |
|
|
loop
|
479 |
|
|
exit when Token /= Tok_Identifier;
|
480 |
|
|
Save_Scan_State (Scan_State); -- at second Id
|
481 |
|
|
Scan; -- past Id
|
482 |
|
|
|
483 |
|
|
if Token = Tok_Colon then
|
484 |
|
|
Error_Msg_SP
|
485 |
|
|
("only one label allowed on block or loop");
|
486 |
|
|
Scan; -- past colon on extra label
|
487 |
|
|
|
488 |
|
|
-- Use the second label as the "real" label
|
489 |
|
|
|
490 |
|
|
Scan_State_Label := Scan_State;
|
491 |
|
|
|
492 |
|
|
-- We will set Error_name as the Block_Label since
|
493 |
|
|
-- we really don't know which of the labels might
|
494 |
|
|
-- be used at the end of the loop or block!
|
495 |
|
|
|
496 |
|
|
Block_Label := Error_Name;
|
497 |
|
|
|
498 |
|
|
-- If Id with no colon, then backup to point to the
|
499 |
|
|
-- Id and we will issue the message below when we try
|
500 |
|
|
-- to scan out the statement as some other form.
|
501 |
|
|
|
502 |
|
|
else
|
503 |
|
|
Restore_Scan_State (Scan_State); -- to second Id
|
504 |
|
|
exit;
|
505 |
|
|
end if;
|
506 |
|
|
end loop;
|
507 |
|
|
|
508 |
|
|
-- Loop_Statement (labeled Loop_Statement)
|
509 |
|
|
|
510 |
|
|
if Token = Tok_Loop then
|
511 |
|
|
Append_To (Statement_List,
|
512 |
|
|
P_Loop_Statement (Id_Node));
|
513 |
|
|
|
514 |
|
|
-- While statement (labeled loop statement with WHILE)
|
515 |
|
|
|
516 |
|
|
elsif Token = Tok_While then
|
517 |
|
|
Append_To (Statement_List,
|
518 |
|
|
P_While_Statement (Id_Node));
|
519 |
|
|
|
520 |
|
|
-- Declare statement (labeled block statement with
|
521 |
|
|
-- DECLARE part)
|
522 |
|
|
|
523 |
|
|
elsif Token = Tok_Declare then
|
524 |
|
|
Append_To (Statement_List,
|
525 |
|
|
P_Declare_Statement (Id_Node));
|
526 |
|
|
|
527 |
|
|
-- Begin statement (labeled block statement with no
|
528 |
|
|
-- DECLARE part)
|
529 |
|
|
|
530 |
|
|
elsif Token = Tok_Begin then
|
531 |
|
|
Append_To (Statement_List,
|
532 |
|
|
P_Begin_Statement (Id_Node));
|
533 |
|
|
|
534 |
|
|
-- For statement (labeled loop statement with FOR)
|
535 |
|
|
|
536 |
|
|
elsif Token = Tok_For then
|
537 |
|
|
Append_To (Statement_List,
|
538 |
|
|
P_For_Statement (Id_Node));
|
539 |
|
|
|
540 |
|
|
-- Improper statement follows label. If we have an
|
541 |
|
|
-- expression token, then assume the colon was part
|
542 |
|
|
-- of a misplaced declaration.
|
543 |
|
|
|
544 |
|
|
elsif Token not in Token_Class_Eterm then
|
545 |
|
|
Restore_Scan_State (Scan_State_Label);
|
546 |
|
|
Junk_Declaration;
|
547 |
|
|
|
548 |
|
|
-- Otherwise complain we have inappropriate statement
|
549 |
|
|
|
550 |
|
|
else
|
551 |
|
|
Error_Msg_AP
|
552 |
|
|
("loop or block statement must follow label");
|
553 |
|
|
end if;
|
554 |
|
|
|
555 |
|
|
Statement_Required := False;
|
556 |
|
|
|
557 |
|
|
-- Here we have an identifier followed by something
|
558 |
|
|
-- other than a colon, semicolon or assignment symbol.
|
559 |
|
|
-- The only valid possibility is a name extension symbol
|
560 |
|
|
|
561 |
|
|
elsif Token in Token_Class_Namext then
|
562 |
|
|
Restore_Scan_State (Scan_State_Label); -- to Id
|
563 |
|
|
Name_Node := P_Name;
|
564 |
|
|
|
565 |
|
|
-- Skip junk right parens in this context
|
566 |
|
|
|
567 |
|
|
Ignore (Tok_Right_Paren);
|
568 |
|
|
|
569 |
|
|
-- Check context following call
|
570 |
|
|
|
571 |
|
|
if Token = Tok_Colon_Equal then
|
572 |
|
|
Scan; -- past colon equal
|
573 |
|
|
Append_To (Statement_List,
|
574 |
|
|
P_Assignment_Statement (Name_Node));
|
575 |
|
|
Statement_Required := False;
|
576 |
|
|
|
577 |
|
|
-- Check common case of = used instead of :=
|
578 |
|
|
|
579 |
|
|
elsif Token = Tok_Equal then
|
580 |
|
|
T_Colon_Equal; -- give := expected message
|
581 |
|
|
Append_To (Statement_List,
|
582 |
|
|
P_Assignment_Statement (Name_Node));
|
583 |
|
|
Statement_Required := False;
|
584 |
|
|
|
585 |
|
|
-- Check apostrophe cases
|
586 |
|
|
|
587 |
|
|
elsif Token = Tok_Apostrophe then
|
588 |
|
|
Append_To (Statement_List,
|
589 |
|
|
P_Code_Statement (Name_Node));
|
590 |
|
|
Statement_Required := False;
|
591 |
|
|
|
592 |
|
|
-- The only other valid item after a name is ; which
|
593 |
|
|
-- means that the item we just scanned was a call.
|
594 |
|
|
|
595 |
|
|
elsif Token = Tok_Semicolon then
|
596 |
|
|
Append_To (Statement_List,
|
597 |
|
|
P_Statement_Name (Name_Node));
|
598 |
|
|
Scan; -- past semicolon
|
599 |
|
|
Statement_Required := False;
|
600 |
|
|
|
601 |
|
|
-- A slash following an identifier or a selected
|
602 |
|
|
-- component in this situation is most likely a period
|
603 |
|
|
-- (see location of keys on keyboard).
|
604 |
|
|
|
605 |
|
|
elsif Token = Tok_Slash
|
606 |
|
|
and then (Nkind (Name_Node) = N_Identifier
|
607 |
|
|
or else
|
608 |
|
|
Nkind (Name_Node) = N_Selected_Component)
|
609 |
|
|
then
|
610 |
|
|
Error_Msg_SC ("""/"" should be "".""");
|
611 |
|
|
Statement_Required := False;
|
612 |
|
|
raise Error_Resync;
|
613 |
|
|
|
614 |
|
|
-- Else we have a missing semicolon
|
615 |
|
|
|
616 |
|
|
else
|
617 |
|
|
TF_Semicolon;
|
618 |
|
|
Statement_Required := False;
|
619 |
|
|
end if;
|
620 |
|
|
|
621 |
|
|
-- If junk after identifier, check if identifier is an
|
622 |
|
|
-- instance of an incorrectly spelled keyword. If so, we
|
623 |
|
|
-- do nothing. The Bad_Spelling_Of will have reset Token
|
624 |
|
|
-- to the appropriate keyword, so the next time round the
|
625 |
|
|
-- loop we will process the modified token. Note that we
|
626 |
|
|
-- check for ELSIF before ELSE here. That's not accidental.
|
627 |
|
|
-- We don't want to identify a misspelling of ELSE as
|
628 |
|
|
-- ELSIF, and in particular we do not want to treat ELSEIF
|
629 |
|
|
-- as ELSE IF.
|
630 |
|
|
|
631 |
|
|
else
|
632 |
|
|
Restore_Scan_State (Scan_State_Label); -- to identifier
|
633 |
|
|
|
634 |
|
|
if Bad_Spelling_Of (Tok_Abort)
|
635 |
|
|
or else Bad_Spelling_Of (Tok_Accept)
|
636 |
|
|
or else Bad_Spelling_Of (Tok_Case)
|
637 |
|
|
or else Bad_Spelling_Of (Tok_Declare)
|
638 |
|
|
or else Bad_Spelling_Of (Tok_Delay)
|
639 |
|
|
or else Bad_Spelling_Of (Tok_Elsif)
|
640 |
|
|
or else Bad_Spelling_Of (Tok_Else)
|
641 |
|
|
or else Bad_Spelling_Of (Tok_End)
|
642 |
|
|
or else Bad_Spelling_Of (Tok_Exception)
|
643 |
|
|
or else Bad_Spelling_Of (Tok_Exit)
|
644 |
|
|
or else Bad_Spelling_Of (Tok_For)
|
645 |
|
|
or else Bad_Spelling_Of (Tok_Goto)
|
646 |
|
|
or else Bad_Spelling_Of (Tok_If)
|
647 |
|
|
or else Bad_Spelling_Of (Tok_Loop)
|
648 |
|
|
or else Bad_Spelling_Of (Tok_Or)
|
649 |
|
|
or else Bad_Spelling_Of (Tok_Pragma)
|
650 |
|
|
or else Bad_Spelling_Of (Tok_Raise)
|
651 |
|
|
or else Bad_Spelling_Of (Tok_Requeue)
|
652 |
|
|
or else Bad_Spelling_Of (Tok_Return)
|
653 |
|
|
or else Bad_Spelling_Of (Tok_Select)
|
654 |
|
|
or else Bad_Spelling_Of (Tok_When)
|
655 |
|
|
or else Bad_Spelling_Of (Tok_While)
|
656 |
|
|
then
|
657 |
|
|
null;
|
658 |
|
|
|
659 |
|
|
-- If not a bad spelling, then we really have junk
|
660 |
|
|
|
661 |
|
|
else
|
662 |
|
|
Scan; -- past identifier again
|
663 |
|
|
|
664 |
|
|
-- If next token is first token on line, then we
|
665 |
|
|
-- consider that we were missing a semicolon after
|
666 |
|
|
-- the identifier, and process it as a procedure
|
667 |
|
|
-- call with no parameters.
|
668 |
|
|
|
669 |
|
|
if Token_Is_At_Start_Of_Line then
|
670 |
|
|
Append_To (Statement_List,
|
671 |
|
|
P_Statement_Name (Id_Node));
|
672 |
|
|
T_Semicolon; -- to give error message
|
673 |
|
|
Statement_Required := False;
|
674 |
|
|
|
675 |
|
|
-- Otherwise we give a missing := message and
|
676 |
|
|
-- simply abandon the junk that is there now.
|
677 |
|
|
|
678 |
|
|
else
|
679 |
|
|
T_Colon_Equal; -- give := expected message
|
680 |
|
|
raise Error_Resync;
|
681 |
|
|
end if;
|
682 |
|
|
|
683 |
|
|
end if;
|
684 |
|
|
end if;
|
685 |
|
|
|
686 |
|
|
-- Statement starting with operator symbol. This could be
|
687 |
|
|
-- a call, a name starting an assignment, or a qualified
|
688 |
|
|
-- expression.
|
689 |
|
|
|
690 |
|
|
when Tok_Operator_Symbol =>
|
691 |
|
|
Check_Bad_Layout;
|
692 |
|
|
Name_Node := P_Name;
|
693 |
|
|
|
694 |
|
|
-- An attempt at a range attribute or a qualified expression
|
695 |
|
|
-- must be illegal here (a code statement cannot possibly
|
696 |
|
|
-- allow qualification by a function name).
|
697 |
|
|
|
698 |
|
|
if Token = Tok_Apostrophe then
|
699 |
|
|
Error_Msg_SC ("apostrophe illegal here");
|
700 |
|
|
raise Error_Resync;
|
701 |
|
|
end if;
|
702 |
|
|
|
703 |
|
|
-- Scan possible assignment if we have a name
|
704 |
|
|
|
705 |
|
|
if Expr_Form = EF_Name
|
706 |
|
|
and then Token = Tok_Colon_Equal
|
707 |
|
|
then
|
708 |
|
|
Scan; -- past colon equal
|
709 |
|
|
Append_To (Statement_List,
|
710 |
|
|
P_Assignment_Statement (Name_Node));
|
711 |
|
|
else
|
712 |
|
|
Append_To (Statement_List,
|
713 |
|
|
P_Statement_Name (Name_Node));
|
714 |
|
|
end if;
|
715 |
|
|
|
716 |
|
|
TF_Semicolon;
|
717 |
|
|
Statement_Required := False;
|
718 |
|
|
|
719 |
|
|
-- Label starting with << which must precede real statement
|
720 |
|
|
|
721 |
|
|
when Tok_Less_Less =>
|
722 |
|
|
Append_To (Statement_List, P_Label);
|
723 |
|
|
Statement_Required := True;
|
724 |
|
|
|
725 |
|
|
-- Pragma appearing as a statement in a statement sequence
|
726 |
|
|
|
727 |
|
|
when Tok_Pragma =>
|
728 |
|
|
Check_Bad_Layout;
|
729 |
|
|
Append_To (Statement_List, P_Pragma);
|
730 |
|
|
|
731 |
|
|
-- Abort_Statement
|
732 |
|
|
|
733 |
|
|
when Tok_Abort =>
|
734 |
|
|
Check_Bad_Layout;
|
735 |
|
|
Append_To (Statement_List, P_Abort_Statement);
|
736 |
|
|
Statement_Required := False;
|
737 |
|
|
|
738 |
|
|
-- Accept_Statement
|
739 |
|
|
|
740 |
|
|
when Tok_Accept =>
|
741 |
|
|
Check_Bad_Layout;
|
742 |
|
|
Append_To (Statement_List, P_Accept_Statement);
|
743 |
|
|
Statement_Required := False;
|
744 |
|
|
|
745 |
|
|
-- Begin_Statement (Block_Statement with no declare, no label)
|
746 |
|
|
|
747 |
|
|
when Tok_Begin =>
|
748 |
|
|
Check_Bad_Layout;
|
749 |
|
|
Append_To (Statement_List, P_Begin_Statement);
|
750 |
|
|
Statement_Required := False;
|
751 |
|
|
|
752 |
|
|
-- Case_Statement
|
753 |
|
|
|
754 |
|
|
when Tok_Case =>
|
755 |
|
|
Check_Bad_Layout;
|
756 |
|
|
Append_To (Statement_List, P_Case_Statement);
|
757 |
|
|
Statement_Required := False;
|
758 |
|
|
|
759 |
|
|
-- Block_Statement with DECLARE and no label
|
760 |
|
|
|
761 |
|
|
when Tok_Declare =>
|
762 |
|
|
Check_Bad_Layout;
|
763 |
|
|
Append_To (Statement_List, P_Declare_Statement);
|
764 |
|
|
Statement_Required := False;
|
765 |
|
|
|
766 |
|
|
-- Delay_Statement
|
767 |
|
|
|
768 |
|
|
when Tok_Delay =>
|
769 |
|
|
Check_Bad_Layout;
|
770 |
|
|
Append_To (Statement_List, P_Delay_Statement);
|
771 |
|
|
Statement_Required := False;
|
772 |
|
|
|
773 |
|
|
-- Exit_Statement
|
774 |
|
|
|
775 |
|
|
when Tok_Exit =>
|
776 |
|
|
Check_Bad_Layout;
|
777 |
|
|
Append_To (Statement_List, P_Exit_Statement);
|
778 |
|
|
Statement_Required := False;
|
779 |
|
|
|
780 |
|
|
-- Loop_Statement with FOR and no label
|
781 |
|
|
|
782 |
|
|
when Tok_For =>
|
783 |
|
|
Check_Bad_Layout;
|
784 |
|
|
Append_To (Statement_List, P_For_Statement);
|
785 |
|
|
Statement_Required := False;
|
786 |
|
|
|
787 |
|
|
-- Goto_Statement
|
788 |
|
|
|
789 |
|
|
when Tok_Goto =>
|
790 |
|
|
Check_Bad_Layout;
|
791 |
|
|
Append_To (Statement_List, P_Goto_Statement);
|
792 |
|
|
Statement_Required := False;
|
793 |
|
|
|
794 |
|
|
-- If_Statement
|
795 |
|
|
|
796 |
|
|
when Tok_If =>
|
797 |
|
|
Check_Bad_Layout;
|
798 |
|
|
Append_To (Statement_List, P_If_Statement);
|
799 |
|
|
Statement_Required := False;
|
800 |
|
|
|
801 |
|
|
-- Loop_Statement
|
802 |
|
|
|
803 |
|
|
when Tok_Loop =>
|
804 |
|
|
Check_Bad_Layout;
|
805 |
|
|
Append_To (Statement_List, P_Loop_Statement);
|
806 |
|
|
Statement_Required := False;
|
807 |
|
|
|
808 |
|
|
-- Null_Statement
|
809 |
|
|
|
810 |
|
|
when Tok_Null =>
|
811 |
|
|
Check_Bad_Layout;
|
812 |
|
|
Append_To (Statement_List, P_Null_Statement);
|
813 |
|
|
Statement_Required := False;
|
814 |
|
|
|
815 |
|
|
-- Raise_Statement
|
816 |
|
|
|
817 |
|
|
when Tok_Raise =>
|
818 |
|
|
Check_Bad_Layout;
|
819 |
|
|
Append_To (Statement_List, P_Raise_Statement);
|
820 |
|
|
Statement_Required := False;
|
821 |
|
|
|
822 |
|
|
-- Requeue_Statement
|
823 |
|
|
|
824 |
|
|
when Tok_Requeue =>
|
825 |
|
|
Check_Bad_Layout;
|
826 |
|
|
Append_To (Statement_List, P_Requeue_Statement);
|
827 |
|
|
Statement_Required := False;
|
828 |
|
|
|
829 |
|
|
-- Return_Statement
|
830 |
|
|
|
831 |
|
|
when Tok_Return =>
|
832 |
|
|
Check_Bad_Layout;
|
833 |
|
|
Append_To (Statement_List, P_Return_Statement);
|
834 |
|
|
Statement_Required := False;
|
835 |
|
|
|
836 |
|
|
-- Select_Statement
|
837 |
|
|
|
838 |
|
|
when Tok_Select =>
|
839 |
|
|
Check_Bad_Layout;
|
840 |
|
|
Append_To (Statement_List, P_Select_Statement);
|
841 |
|
|
Statement_Required := False;
|
842 |
|
|
|
843 |
|
|
-- While_Statement (Block_Statement with while and no loop)
|
844 |
|
|
|
845 |
|
|
when Tok_While =>
|
846 |
|
|
Check_Bad_Layout;
|
847 |
|
|
Append_To (Statement_List, P_While_Statement);
|
848 |
|
|
Statement_Required := False;
|
849 |
|
|
|
850 |
|
|
-- Anything else is some kind of junk, signal an error message
|
851 |
|
|
-- and then raise Error_Resync, to merge with the normal
|
852 |
|
|
-- handling of a bad statement.
|
853 |
|
|
|
854 |
|
|
when others =>
|
855 |
|
|
|
856 |
|
|
if Token in Token_Class_Declk then
|
857 |
|
|
Junk_Declaration;
|
858 |
|
|
|
859 |
|
|
else
|
860 |
|
|
Error_Msg_BC ("statement expected");
|
861 |
|
|
raise Error_Resync;
|
862 |
|
|
end if;
|
863 |
|
|
end case;
|
864 |
|
|
|
865 |
|
|
-- On error resynchronization, skip past next semicolon, and, since
|
866 |
|
|
-- we are still in the statement loop, look for next statement. We
|
867 |
|
|
-- set Statement_Required False to avoid an unnecessary error message
|
868 |
|
|
-- complaining that no statement was found (i.e. we consider the
|
869 |
|
|
-- junk to satisfy the requirement for a statement being present).
|
870 |
|
|
|
871 |
|
|
exception
|
872 |
|
|
when Error_Resync =>
|
873 |
|
|
Resync_Past_Semicolon_Or_To_Loop_Or_Then;
|
874 |
|
|
Statement_Required := False;
|
875 |
|
|
end;
|
876 |
|
|
|
877 |
|
|
exit when SS_Flags.Unco;
|
878 |
|
|
|
879 |
|
|
end loop;
|
880 |
|
|
|
881 |
|
|
return Statement_List;
|
882 |
|
|
|
883 |
|
|
end P_Sequence_Of_Statements;
|
884 |
|
|
|
885 |
|
|
--------------------
|
886 |
|
|
-- 5.1 Statement --
|
887 |
|
|
--------------------
|
888 |
|
|
|
889 |
|
|
-- Parsed by P_Sequence_Of_Statements (5.1), except for the case
|
890 |
|
|
-- of a statement of the form of a name, which is handled here. The
|
891 |
|
|
-- argument passed in is the tree for the name which has been scanned
|
892 |
|
|
-- The returned value is the corresponding statement form.
|
893 |
|
|
|
894 |
|
|
-- This routine is also used by Par.Prag for processing the procedure
|
895 |
|
|
-- call that appears as the second argument of a pragma Assert.
|
896 |
|
|
|
897 |
|
|
-- Error recovery: cannot raise Error_Resync
|
898 |
|
|
|
899 |
|
|
function P_Statement_Name (Name_Node : Node_Id) return Node_Id is
|
900 |
|
|
Stmt_Node : Node_Id;
|
901 |
|
|
|
902 |
|
|
begin
|
903 |
|
|
-- Case of Indexed component, which is a procedure call with arguments
|
904 |
|
|
|
905 |
|
|
if Nkind (Name_Node) = N_Indexed_Component then
|
906 |
|
|
declare
|
907 |
|
|
Prefix_Node : constant Node_Id := Prefix (Name_Node);
|
908 |
|
|
Exprs_Node : constant List_Id := Expressions (Name_Node);
|
909 |
|
|
|
910 |
|
|
begin
|
911 |
|
|
Change_Node (Name_Node, N_Procedure_Call_Statement);
|
912 |
|
|
Set_Name (Name_Node, Prefix_Node);
|
913 |
|
|
Set_Parameter_Associations (Name_Node, Exprs_Node);
|
914 |
|
|
return Name_Node;
|
915 |
|
|
end;
|
916 |
|
|
|
917 |
|
|
-- Case of function call node, which is a really a procedure call
|
918 |
|
|
|
919 |
|
|
elsif Nkind (Name_Node) = N_Function_Call then
|
920 |
|
|
declare
|
921 |
|
|
Fname_Node : constant Node_Id := Name (Name_Node);
|
922 |
|
|
Params_List : constant List_Id :=
|
923 |
|
|
Parameter_Associations (Name_Node);
|
924 |
|
|
|
925 |
|
|
begin
|
926 |
|
|
Change_Node (Name_Node, N_Procedure_Call_Statement);
|
927 |
|
|
Set_Name (Name_Node, Fname_Node);
|
928 |
|
|
Set_Parameter_Associations (Name_Node, Params_List);
|
929 |
|
|
return Name_Node;
|
930 |
|
|
end;
|
931 |
|
|
|
932 |
|
|
-- Case of call to attribute that denotes a procedure. Here we
|
933 |
|
|
-- just leave the attribute reference unchanged.
|
934 |
|
|
|
935 |
|
|
elsif Nkind (Name_Node) = N_Attribute_Reference
|
936 |
|
|
and then Is_Procedure_Attribute_Name (Attribute_Name (Name_Node))
|
937 |
|
|
then
|
938 |
|
|
return Name_Node;
|
939 |
|
|
|
940 |
|
|
-- All other cases of names are parameterless procedure calls
|
941 |
|
|
|
942 |
|
|
else
|
943 |
|
|
Stmt_Node :=
|
944 |
|
|
New_Node (N_Procedure_Call_Statement, Sloc (Name_Node));
|
945 |
|
|
Set_Name (Stmt_Node, Name_Node);
|
946 |
|
|
return Stmt_Node;
|
947 |
|
|
end if;
|
948 |
|
|
|
949 |
|
|
end P_Statement_Name;
|
950 |
|
|
|
951 |
|
|
---------------------------
|
952 |
|
|
-- 5.1 Simple Statement --
|
953 |
|
|
---------------------------
|
954 |
|
|
|
955 |
|
|
-- Parsed by P_Sequence_Of_Statements (5.1)
|
956 |
|
|
|
957 |
|
|
-----------------------------
|
958 |
|
|
-- 5.1 Compound Statement --
|
959 |
|
|
-----------------------------
|
960 |
|
|
|
961 |
|
|
-- Parsed by P_Sequence_Of_Statements (5.1)
|
962 |
|
|
|
963 |
|
|
-------------------------
|
964 |
|
|
-- 5.1 Null Statement --
|
965 |
|
|
-------------------------
|
966 |
|
|
|
967 |
|
|
-- NULL_STATEMENT ::= null;
|
968 |
|
|
|
969 |
|
|
-- The caller has already checked that the current token is null
|
970 |
|
|
|
971 |
|
|
-- Error recovery: cannot raise Error_Resync
|
972 |
|
|
|
973 |
|
|
function P_Null_Statement return Node_Id is
|
974 |
|
|
Null_Stmt_Node : Node_Id;
|
975 |
|
|
|
976 |
|
|
begin
|
977 |
|
|
Null_Stmt_Node := New_Node (N_Null_Statement, Token_Ptr);
|
978 |
|
|
Scan; -- past NULL
|
979 |
|
|
TF_Semicolon;
|
980 |
|
|
return Null_Stmt_Node;
|
981 |
|
|
end P_Null_Statement;
|
982 |
|
|
|
983 |
|
|
----------------
|
984 |
|
|
-- 5.1 Label --
|
985 |
|
|
----------------
|
986 |
|
|
|
987 |
|
|
-- LABEL ::= <<label_STATEMENT_IDENTIFIER>>
|
988 |
|
|
|
989 |
|
|
-- STATEMENT_IDENTIFIER ::= DIRECT_NAME
|
990 |
|
|
|
991 |
|
|
-- The IDENTIFIER of a STATEMENT_IDENTIFIER shall be an identifier
|
992 |
|
|
-- (not an OPERATOR_SYMBOL)
|
993 |
|
|
|
994 |
|
|
-- The caller has already checked that the current token is <<
|
995 |
|
|
|
996 |
|
|
-- Error recovery: can raise Error_Resync
|
997 |
|
|
|
998 |
|
|
function P_Label return Node_Id is
|
999 |
|
|
Label_Node : Node_Id;
|
1000 |
|
|
|
1001 |
|
|
begin
|
1002 |
|
|
Label_Node := New_Node (N_Label, Token_Ptr);
|
1003 |
|
|
Scan; -- past <<
|
1004 |
|
|
Set_Identifier (Label_Node, P_Identifier (C_Greater_Greater));
|
1005 |
|
|
T_Greater_Greater;
|
1006 |
|
|
Append_Elmt (Label_Node, Label_List);
|
1007 |
|
|
return Label_Node;
|
1008 |
|
|
end P_Label;
|
1009 |
|
|
|
1010 |
|
|
-------------------------------
|
1011 |
|
|
-- 5.1 Statement Identifier --
|
1012 |
|
|
-------------------------------
|
1013 |
|
|
|
1014 |
|
|
-- Statement label is parsed by P_Label (5.1)
|
1015 |
|
|
|
1016 |
|
|
-- Loop label is parsed by P_Loop_Statement (5.5), P_For_Statement (5.5)
|
1017 |
|
|
-- or P_While_Statement (5.5)
|
1018 |
|
|
|
1019 |
|
|
-- Block label is parsed by P_Begin_Statement (5.6) or
|
1020 |
|
|
-- P_Declare_Statement (5.6)
|
1021 |
|
|
|
1022 |
|
|
-------------------------------
|
1023 |
|
|
-- 5.2 Assignment Statement --
|
1024 |
|
|
-------------------------------
|
1025 |
|
|
|
1026 |
|
|
-- ASSIGNMENT_STATEMENT ::=
|
1027 |
|
|
-- variable_NAME := EXPRESSION;
|
1028 |
|
|
|
1029 |
|
|
-- Error recovery: can raise Error_Resync
|
1030 |
|
|
|
1031 |
|
|
function P_Assignment_Statement (LHS : Node_Id) return Node_Id is
|
1032 |
|
|
Assign_Node : Node_Id;
|
1033 |
|
|
|
1034 |
|
|
begin
|
1035 |
|
|
Assign_Node := New_Node (N_Assignment_Statement, Prev_Token_Ptr);
|
1036 |
|
|
Set_Name (Assign_Node, LHS);
|
1037 |
|
|
Set_Expression (Assign_Node, P_Expression_No_Right_Paren);
|
1038 |
|
|
TF_Semicolon;
|
1039 |
|
|
return Assign_Node;
|
1040 |
|
|
end P_Assignment_Statement;
|
1041 |
|
|
|
1042 |
|
|
-----------------------
|
1043 |
|
|
-- 5.3 If Statement --
|
1044 |
|
|
-----------------------
|
1045 |
|
|
|
1046 |
|
|
-- IF_STATEMENT ::=
|
1047 |
|
|
-- if CONDITION then
|
1048 |
|
|
-- SEQUENCE_OF_STATEMENTS
|
1049 |
|
|
-- {elsif CONDITION then
|
1050 |
|
|
-- SEQUENCE_OF_STATEMENTS}
|
1051 |
|
|
-- [else
|
1052 |
|
|
-- SEQUENCE_OF_STATEMENTS]
|
1053 |
|
|
-- end if;
|
1054 |
|
|
|
1055 |
|
|
-- The caller has checked that the initial token is IF (or in the error
|
1056 |
|
|
-- case of a mysterious THEN, the initial token may simply be THEN, in
|
1057 |
|
|
-- which case, no condition (or IF) was scanned).
|
1058 |
|
|
|
1059 |
|
|
-- Error recovery: can raise Error_Resync
|
1060 |
|
|
|
1061 |
|
|
function P_If_Statement return Node_Id is
|
1062 |
|
|
If_Node : Node_Id;
|
1063 |
|
|
Elsif_Node : Node_Id;
|
1064 |
|
|
Loc : Source_Ptr;
|
1065 |
|
|
|
1066 |
|
|
procedure Add_Elsif_Part;
|
1067 |
|
|
-- An internal procedure used to scan out a single ELSIF part. On entry
|
1068 |
|
|
-- the ELSIF (or an ELSE which has been determined should be ELSIF) is
|
1069 |
|
|
-- scanned out and is in Prev_Token.
|
1070 |
|
|
|
1071 |
|
|
procedure Check_If_Column;
|
1072 |
|
|
-- An internal procedure used to check that THEN, ELSE, or ELSIF
|
1073 |
|
|
-- appear in the right place if column checking is enabled (i.e. if
|
1074 |
|
|
-- they are the first token on the line, then they must appear in
|
1075 |
|
|
-- the same column as the opening IF).
|
1076 |
|
|
|
1077 |
|
|
procedure Check_Then_Column;
|
1078 |
|
|
-- This procedure carries out the style checks for a THEN token
|
1079 |
|
|
-- Note that the caller has set Loc to the Source_Ptr value for
|
1080 |
|
|
-- the previous IF or ELSIF token. These checks apply only to a
|
1081 |
|
|
-- THEN at the start of a line.
|
1082 |
|
|
|
1083 |
|
|
function Else_Should_Be_Elsif return Boolean;
|
1084 |
|
|
-- An internal routine used to do a special error recovery check when
|
1085 |
|
|
-- an ELSE is encountered. It determines if the ELSE should be treated
|
1086 |
|
|
-- as an ELSIF. A positive decision (TRUE returned, is made if the ELSE
|
1087 |
|
|
-- is followed by a sequence of tokens, starting on the same line as
|
1088 |
|
|
-- the ELSE, which are not expression terminators, followed by a THEN.
|
1089 |
|
|
-- On entry, the ELSE has been scanned out.
|
1090 |
|
|
|
1091 |
|
|
procedure Add_Elsif_Part is
|
1092 |
|
|
begin
|
1093 |
|
|
if No (Elsif_Parts (If_Node)) then
|
1094 |
|
|
Set_Elsif_Parts (If_Node, New_List);
|
1095 |
|
|
end if;
|
1096 |
|
|
|
1097 |
|
|
Elsif_Node := New_Node (N_Elsif_Part, Prev_Token_Ptr);
|
1098 |
|
|
Loc := Prev_Token_Ptr;
|
1099 |
|
|
Set_Condition (Elsif_Node, P_Condition);
|
1100 |
|
|
Check_Then_Column;
|
1101 |
|
|
Then_Scan;
|
1102 |
|
|
Set_Then_Statements
|
1103 |
|
|
(Elsif_Node, P_Sequence_Of_Statements (SS_Eftm_Eltm_Sreq));
|
1104 |
|
|
Append (Elsif_Node, Elsif_Parts (If_Node));
|
1105 |
|
|
end Add_Elsif_Part;
|
1106 |
|
|
|
1107 |
|
|
procedure Check_If_Column is
|
1108 |
|
|
begin
|
1109 |
|
|
if RM_Column_Check and then Token_Is_At_Start_Of_Line
|
1110 |
|
|
and then Start_Column /= Scope.Table (Scope.Last).Ecol
|
1111 |
|
|
then
|
1112 |
|
|
Error_Msg_Col := Scope.Table (Scope.Last).Ecol;
|
1113 |
|
|
Error_Msg_SC ("(style) this token should be@");
|
1114 |
|
|
end if;
|
1115 |
|
|
end Check_If_Column;
|
1116 |
|
|
|
1117 |
|
|
procedure Check_Then_Column is
|
1118 |
|
|
begin
|
1119 |
|
|
if Token_Is_At_Start_Of_Line and then Token = Tok_Then then
|
1120 |
|
|
Check_If_Column;
|
1121 |
|
|
|
1122 |
|
|
if Style_Check then
|
1123 |
|
|
Style.Check_Then (Loc);
|
1124 |
|
|
end if;
|
1125 |
|
|
end if;
|
1126 |
|
|
end Check_Then_Column;
|
1127 |
|
|
|
1128 |
|
|
function Else_Should_Be_Elsif return Boolean is
|
1129 |
|
|
Scan_State : Saved_Scan_State;
|
1130 |
|
|
|
1131 |
|
|
begin
|
1132 |
|
|
if Token_Is_At_Start_Of_Line then
|
1133 |
|
|
return False;
|
1134 |
|
|
|
1135 |
|
|
else
|
1136 |
|
|
Save_Scan_State (Scan_State);
|
1137 |
|
|
|
1138 |
|
|
loop
|
1139 |
|
|
if Token in Token_Class_Eterm then
|
1140 |
|
|
Restore_Scan_State (Scan_State);
|
1141 |
|
|
return False;
|
1142 |
|
|
else
|
1143 |
|
|
Scan; -- past non-expression terminating token
|
1144 |
|
|
|
1145 |
|
|
if Token = Tok_Then then
|
1146 |
|
|
Restore_Scan_State (Scan_State);
|
1147 |
|
|
return True;
|
1148 |
|
|
end if;
|
1149 |
|
|
end if;
|
1150 |
|
|
end loop;
|
1151 |
|
|
end if;
|
1152 |
|
|
end Else_Should_Be_Elsif;
|
1153 |
|
|
|
1154 |
|
|
-- Start of processing for P_If_Statement
|
1155 |
|
|
|
1156 |
|
|
begin
|
1157 |
|
|
If_Node := New_Node (N_If_Statement, Token_Ptr);
|
1158 |
|
|
|
1159 |
|
|
Push_Scope_Stack;
|
1160 |
|
|
Scope.Table (Scope.Last).Etyp := E_If;
|
1161 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1162 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1163 |
|
|
Scope.Table (Scope.Last).Labl := Error;
|
1164 |
|
|
Scope.Table (Scope.Last).Node := If_Node;
|
1165 |
|
|
|
1166 |
|
|
if Token = Tok_If then
|
1167 |
|
|
Loc := Token_Ptr;
|
1168 |
|
|
Scan; -- past IF
|
1169 |
|
|
Set_Condition (If_Node, P_Condition);
|
1170 |
|
|
|
1171 |
|
|
-- Deal with misuse of IF expression => used instead
|
1172 |
|
|
-- of WHEN expression =>
|
1173 |
|
|
|
1174 |
|
|
if Token = Tok_Arrow then
|
1175 |
|
|
Error_Msg_SC ("THEN expected");
|
1176 |
|
|
Scan; -- past the arrow
|
1177 |
|
|
Pop_Scope_Stack; -- remove unneeded entry
|
1178 |
|
|
raise Error_Resync;
|
1179 |
|
|
end if;
|
1180 |
|
|
|
1181 |
|
|
Check_Then_Column;
|
1182 |
|
|
|
1183 |
|
|
else
|
1184 |
|
|
Error_Msg_SC ("no IF for this THEN");
|
1185 |
|
|
Set_Condition (If_Node, Error);
|
1186 |
|
|
end if;
|
1187 |
|
|
|
1188 |
|
|
Then_Scan;
|
1189 |
|
|
|
1190 |
|
|
Set_Then_Statements
|
1191 |
|
|
(If_Node, P_Sequence_Of_Statements (SS_Eftm_Eltm_Sreq));
|
1192 |
|
|
|
1193 |
|
|
-- This loop scans out else and elsif parts
|
1194 |
|
|
|
1195 |
|
|
loop
|
1196 |
|
|
if Token = Tok_Elsif then
|
1197 |
|
|
Check_If_Column;
|
1198 |
|
|
|
1199 |
|
|
if Present (Else_Statements (If_Node)) then
|
1200 |
|
|
Error_Msg_SP ("ELSIF cannot appear after ELSE");
|
1201 |
|
|
end if;
|
1202 |
|
|
|
1203 |
|
|
Scan; -- past ELSIF
|
1204 |
|
|
Add_Elsif_Part;
|
1205 |
|
|
|
1206 |
|
|
elsif Token = Tok_Else then
|
1207 |
|
|
Check_If_Column;
|
1208 |
|
|
Scan; -- past ELSE
|
1209 |
|
|
|
1210 |
|
|
if Else_Should_Be_Elsif then
|
1211 |
|
|
Error_Msg_SP ("ELSE should be ELSIF");
|
1212 |
|
|
Add_Elsif_Part;
|
1213 |
|
|
|
1214 |
|
|
else
|
1215 |
|
|
-- Here we have an else that really is an else
|
1216 |
|
|
|
1217 |
|
|
if Present (Else_Statements (If_Node)) then
|
1218 |
|
|
Error_Msg_SP ("only one ELSE part allowed");
|
1219 |
|
|
Append_List
|
1220 |
|
|
(P_Sequence_Of_Statements (SS_Eftm_Eltm_Sreq),
|
1221 |
|
|
Else_Statements (If_Node));
|
1222 |
|
|
else
|
1223 |
|
|
Set_Else_Statements
|
1224 |
|
|
(If_Node, P_Sequence_Of_Statements (SS_Eftm_Eltm_Sreq));
|
1225 |
|
|
end if;
|
1226 |
|
|
end if;
|
1227 |
|
|
|
1228 |
|
|
-- If anything other than ELSE or ELSIF, exit the loop. The token
|
1229 |
|
|
-- had better be END (and in fact it had better be END IF), but
|
1230 |
|
|
-- we will let End_Statements take care of checking that.
|
1231 |
|
|
|
1232 |
|
|
else
|
1233 |
|
|
exit;
|
1234 |
|
|
end if;
|
1235 |
|
|
end loop;
|
1236 |
|
|
|
1237 |
|
|
End_Statements;
|
1238 |
|
|
return If_Node;
|
1239 |
|
|
|
1240 |
|
|
end P_If_Statement;
|
1241 |
|
|
|
1242 |
|
|
--------------------
|
1243 |
|
|
-- 5.3 Condition --
|
1244 |
|
|
--------------------
|
1245 |
|
|
|
1246 |
|
|
-- CONDITION ::= boolean_EXPRESSION
|
1247 |
|
|
|
1248 |
|
|
function P_Condition return Node_Id is
|
1249 |
|
|
Cond : Node_Id;
|
1250 |
|
|
|
1251 |
|
|
begin
|
1252 |
|
|
Cond := P_Expression_No_Right_Paren;
|
1253 |
|
|
|
1254 |
|
|
-- It is never possible for := to follow a condition, so if we get
|
1255 |
|
|
-- a := we assume it is a mistyped equality. Note that we do not try
|
1256 |
|
|
-- to reconstruct the tree correctly in this case, but we do at least
|
1257 |
|
|
-- give an accurate error message.
|
1258 |
|
|
|
1259 |
|
|
if Token = Tok_Colon_Equal then
|
1260 |
|
|
while Token = Tok_Colon_Equal loop
|
1261 |
|
|
Error_Msg_SC (""":="" should be ""=""");
|
1262 |
|
|
Scan; -- past junk :=
|
1263 |
|
|
Discard_Junk_Node (P_Expression_No_Right_Paren);
|
1264 |
|
|
end loop;
|
1265 |
|
|
|
1266 |
|
|
return Cond;
|
1267 |
|
|
|
1268 |
|
|
-- Otherwise check for redundant parens
|
1269 |
|
|
|
1270 |
|
|
else
|
1271 |
|
|
if Style_Check
|
1272 |
|
|
and then Paren_Count (Cond) > 0
|
1273 |
|
|
then
|
1274 |
|
|
Style.Check_Xtra_Parens (First_Sloc (Cond));
|
1275 |
|
|
end if;
|
1276 |
|
|
|
1277 |
|
|
-- And return the result
|
1278 |
|
|
|
1279 |
|
|
return Cond;
|
1280 |
|
|
end if;
|
1281 |
|
|
end P_Condition;
|
1282 |
|
|
|
1283 |
|
|
-------------------------
|
1284 |
|
|
-- 5.4 Case Statement --
|
1285 |
|
|
-------------------------
|
1286 |
|
|
|
1287 |
|
|
-- CASE_STATEMENT ::=
|
1288 |
|
|
-- case EXPRESSION is
|
1289 |
|
|
-- CASE_STATEMENT_ALTERNATIVE
|
1290 |
|
|
-- {CASE_STATEMENT_ALTERNATIVE}
|
1291 |
|
|
-- end case;
|
1292 |
|
|
|
1293 |
|
|
-- The caller has checked that the first token is CASE
|
1294 |
|
|
|
1295 |
|
|
-- Can raise Error_Resync
|
1296 |
|
|
|
1297 |
|
|
function P_Case_Statement return Node_Id is
|
1298 |
|
|
Case_Node : Node_Id;
|
1299 |
|
|
Alternatives_List : List_Id;
|
1300 |
|
|
First_When_Loc : Source_Ptr;
|
1301 |
|
|
|
1302 |
|
|
begin
|
1303 |
|
|
Case_Node := New_Node (N_Case_Statement, Token_Ptr);
|
1304 |
|
|
|
1305 |
|
|
Push_Scope_Stack;
|
1306 |
|
|
Scope.Table (Scope.Last).Etyp := E_Case;
|
1307 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1308 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1309 |
|
|
Scope.Table (Scope.Last).Labl := Error;
|
1310 |
|
|
Scope.Table (Scope.Last).Node := Case_Node;
|
1311 |
|
|
|
1312 |
|
|
Scan; -- past CASE
|
1313 |
|
|
Set_Expression (Case_Node, P_Expression_No_Right_Paren);
|
1314 |
|
|
TF_Is;
|
1315 |
|
|
|
1316 |
|
|
-- Prepare to parse case statement alternatives
|
1317 |
|
|
|
1318 |
|
|
Alternatives_List := New_List;
|
1319 |
|
|
P_Pragmas_Opt (Alternatives_List);
|
1320 |
|
|
First_When_Loc := Token_Ptr;
|
1321 |
|
|
|
1322 |
|
|
-- Loop through case statement alternatives
|
1323 |
|
|
|
1324 |
|
|
loop
|
1325 |
|
|
-- If we have a WHEN or OTHERS, then that's fine keep going. Note
|
1326 |
|
|
-- that it is a semantic check to ensure the proper use of OTHERS
|
1327 |
|
|
|
1328 |
|
|
if Token = Tok_When or else Token = Tok_Others then
|
1329 |
|
|
Append (P_Case_Statement_Alternative, Alternatives_List);
|
1330 |
|
|
|
1331 |
|
|
-- If we have an END, then probably we are at the end of the case
|
1332 |
|
|
-- but we only exit if Check_End thinks the END was reasonable.
|
1333 |
|
|
|
1334 |
|
|
elsif Token = Tok_End then
|
1335 |
|
|
exit when Check_End;
|
1336 |
|
|
|
1337 |
|
|
-- Here if token is other than WHEN, OTHERS or END. We definitely
|
1338 |
|
|
-- have an error, but the question is whether or not to get out of
|
1339 |
|
|
-- the case statement. We don't want to get out early, or we will
|
1340 |
|
|
-- get a slew of junk error messages for subsequent when tokens.
|
1341 |
|
|
|
1342 |
|
|
-- If the token is not at the start of the line, or if it is indented
|
1343 |
|
|
-- with respect to the current case statement, then the best guess is
|
1344 |
|
|
-- that we are still supposed to be inside the case statement. We
|
1345 |
|
|
-- complain about the missing WHEN, and discard the junk statements.
|
1346 |
|
|
|
1347 |
|
|
elsif not Token_Is_At_Start_Of_Line
|
1348 |
|
|
or else Start_Column > Scope.Table (Scope.Last).Ecol
|
1349 |
|
|
then
|
1350 |
|
|
Error_Msg_BC ("WHEN (case statement alternative) expected");
|
1351 |
|
|
|
1352 |
|
|
-- Here is a possibility for infinite looping if we don't make
|
1353 |
|
|
-- progress. So try to process statements, otherwise exit
|
1354 |
|
|
|
1355 |
|
|
declare
|
1356 |
|
|
Error_Ptr : constant Source_Ptr := Scan_Ptr;
|
1357 |
|
|
begin
|
1358 |
|
|
Discard_Junk_List (P_Sequence_Of_Statements (SS_Whtm));
|
1359 |
|
|
exit when Scan_Ptr = Error_Ptr and then Check_End;
|
1360 |
|
|
end;
|
1361 |
|
|
|
1362 |
|
|
-- Here we have a junk token at the start of the line and it is
|
1363 |
|
|
-- not indented. If Check_End thinks there is a missing END, then
|
1364 |
|
|
-- we will get out of the case, otherwise we keep going.
|
1365 |
|
|
|
1366 |
|
|
else
|
1367 |
|
|
exit when Check_End;
|
1368 |
|
|
end if;
|
1369 |
|
|
end loop;
|
1370 |
|
|
|
1371 |
|
|
-- Make sure we have at least one alternative
|
1372 |
|
|
|
1373 |
|
|
if No (First_Non_Pragma (Alternatives_List)) then
|
1374 |
|
|
Error_Msg
|
1375 |
|
|
("WHEN expected, must have at least one alternative in case",
|
1376 |
|
|
First_When_Loc);
|
1377 |
|
|
return Error;
|
1378 |
|
|
|
1379 |
|
|
else
|
1380 |
|
|
Set_Alternatives (Case_Node, Alternatives_List);
|
1381 |
|
|
return Case_Node;
|
1382 |
|
|
end if;
|
1383 |
|
|
end P_Case_Statement;
|
1384 |
|
|
|
1385 |
|
|
-------------------------------------
|
1386 |
|
|
-- 5.4 Case Statement Alternative --
|
1387 |
|
|
-------------------------------------
|
1388 |
|
|
|
1389 |
|
|
-- CASE_STATEMENT_ALTERNATIVE ::=
|
1390 |
|
|
-- when DISCRETE_CHOICE_LIST =>
|
1391 |
|
|
-- SEQUENCE_OF_STATEMENTS
|
1392 |
|
|
|
1393 |
|
|
-- The caller has checked that the initial token is WHEN or OTHERS
|
1394 |
|
|
-- Error recovery: can raise Error_Resync
|
1395 |
|
|
|
1396 |
|
|
function P_Case_Statement_Alternative return Node_Id is
|
1397 |
|
|
Case_Alt_Node : Node_Id;
|
1398 |
|
|
|
1399 |
|
|
begin
|
1400 |
|
|
if Style_Check then
|
1401 |
|
|
Style.Check_Indentation;
|
1402 |
|
|
end if;
|
1403 |
|
|
|
1404 |
|
|
Case_Alt_Node := New_Node (N_Case_Statement_Alternative, Token_Ptr);
|
1405 |
|
|
T_When; -- past WHEN (or give error in OTHERS case)
|
1406 |
|
|
Set_Discrete_Choices (Case_Alt_Node, P_Discrete_Choice_List);
|
1407 |
|
|
TF_Arrow;
|
1408 |
|
|
Set_Statements (Case_Alt_Node, P_Sequence_Of_Statements (SS_Sreq_Whtm));
|
1409 |
|
|
return Case_Alt_Node;
|
1410 |
|
|
end P_Case_Statement_Alternative;
|
1411 |
|
|
|
1412 |
|
|
-------------------------
|
1413 |
|
|
-- 5.5 Loop Statement --
|
1414 |
|
|
-------------------------
|
1415 |
|
|
|
1416 |
|
|
-- LOOP_STATEMENT ::=
|
1417 |
|
|
-- [LOOP_STATEMENT_IDENTIFIER:]
|
1418 |
|
|
-- [ITERATION_SCHEME] loop
|
1419 |
|
|
-- SEQUENCE_OF_STATEMENTS
|
1420 |
|
|
-- end loop [loop_IDENTIFIER];
|
1421 |
|
|
|
1422 |
|
|
-- ITERATION_SCHEME ::=
|
1423 |
|
|
-- while CONDITION
|
1424 |
|
|
-- | for LOOP_PARAMETER_SPECIFICATION
|
1425 |
|
|
|
1426 |
|
|
-- The parsing of loop statements is handled by one of three functions
|
1427 |
|
|
-- P_Loop_Statement, P_For_Statement or P_While_Statement depending
|
1428 |
|
|
-- on the initial keyword in the construct (excluding the identifier)
|
1429 |
|
|
|
1430 |
|
|
-- P_Loop_Statement
|
1431 |
|
|
|
1432 |
|
|
-- This function parses the case where no iteration scheme is present
|
1433 |
|
|
|
1434 |
|
|
-- The caller has checked that the initial token is LOOP. The parameter
|
1435 |
|
|
-- is the node identifiers for the loop label if any (or is set to Empty
|
1436 |
|
|
-- if there is no loop label).
|
1437 |
|
|
|
1438 |
|
|
-- Error recovery : cannot raise Error_Resync
|
1439 |
|
|
|
1440 |
|
|
function P_Loop_Statement (Loop_Name : Node_Id := Empty) return Node_Id is
|
1441 |
|
|
Loop_Node : Node_Id;
|
1442 |
|
|
Created_Name : Node_Id;
|
1443 |
|
|
|
1444 |
|
|
begin
|
1445 |
|
|
Push_Scope_Stack;
|
1446 |
|
|
Scope.Table (Scope.Last).Labl := Loop_Name;
|
1447 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1448 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1449 |
|
|
Scope.Table (Scope.Last).Etyp := E_Loop;
|
1450 |
|
|
|
1451 |
|
|
Loop_Node := New_Node (N_Loop_Statement, Token_Ptr);
|
1452 |
|
|
TF_Loop;
|
1453 |
|
|
|
1454 |
|
|
if No (Loop_Name) then
|
1455 |
|
|
Created_Name :=
|
1456 |
|
|
Make_Identifier (Sloc (Loop_Node),
|
1457 |
|
|
Chars => Set_Loop_Block_Name ('L'));
|
1458 |
|
|
Set_Comes_From_Source (Created_Name, False);
|
1459 |
|
|
Set_Has_Created_Identifier (Loop_Node, True);
|
1460 |
|
|
Set_Identifier (Loop_Node, Created_Name);
|
1461 |
|
|
Scope.Table (Scope.Last).Labl := Created_Name;
|
1462 |
|
|
else
|
1463 |
|
|
Set_Identifier (Loop_Node, Loop_Name);
|
1464 |
|
|
end if;
|
1465 |
|
|
|
1466 |
|
|
Append_Elmt (Loop_Node, Label_List);
|
1467 |
|
|
Set_Statements (Loop_Node, P_Sequence_Of_Statements (SS_Sreq));
|
1468 |
|
|
End_Statements (Loop_Node);
|
1469 |
|
|
return Loop_Node;
|
1470 |
|
|
end P_Loop_Statement;
|
1471 |
|
|
|
1472 |
|
|
-- P_For_Statement
|
1473 |
|
|
|
1474 |
|
|
-- This function parses a loop statement with a FOR iteration scheme
|
1475 |
|
|
|
1476 |
|
|
-- The caller has checked that the initial token is FOR. The parameter
|
1477 |
|
|
-- is the node identifier for the block label if any (or is set to Empty
|
1478 |
|
|
-- if there is no block label).
|
1479 |
|
|
|
1480 |
|
|
-- Note: the caller fills in the Identifier field if a label was present
|
1481 |
|
|
|
1482 |
|
|
-- Error recovery: can raise Error_Resync
|
1483 |
|
|
|
1484 |
|
|
function P_For_Statement (Loop_Name : Node_Id := Empty) return Node_Id is
|
1485 |
|
|
Loop_Node : Node_Id;
|
1486 |
|
|
Iter_Scheme_Node : Node_Id;
|
1487 |
|
|
Loop_For_Flag : Boolean;
|
1488 |
|
|
Created_Name : Node_Id;
|
1489 |
|
|
|
1490 |
|
|
begin
|
1491 |
|
|
Push_Scope_Stack;
|
1492 |
|
|
Scope.Table (Scope.Last).Labl := Loop_Name;
|
1493 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1494 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1495 |
|
|
Scope.Table (Scope.Last).Etyp := E_Loop;
|
1496 |
|
|
|
1497 |
|
|
Loop_For_Flag := (Prev_Token = Tok_Loop);
|
1498 |
|
|
Scan; -- past FOR
|
1499 |
|
|
Iter_Scheme_Node := New_Node (N_Iteration_Scheme, Token_Ptr);
|
1500 |
|
|
Set_Loop_Parameter_Specification
|
1501 |
|
|
(Iter_Scheme_Node, P_Loop_Parameter_Specification);
|
1502 |
|
|
|
1503 |
|
|
-- The following is a special test so that a miswritten for loop such
|
1504 |
|
|
-- as "loop for I in 1..10;" is handled nicely, without making an extra
|
1505 |
|
|
-- entry in the scope stack. We don't bother to actually fix up the
|
1506 |
|
|
-- tree in this case since it's not worth the effort. Instead we just
|
1507 |
|
|
-- eat up the loop junk, leaving the entry for what now looks like an
|
1508 |
|
|
-- unmodified loop intact.
|
1509 |
|
|
|
1510 |
|
|
if Loop_For_Flag and then Token = Tok_Semicolon then
|
1511 |
|
|
Error_Msg_SC ("LOOP belongs here, not before FOR");
|
1512 |
|
|
Pop_Scope_Stack;
|
1513 |
|
|
return Error;
|
1514 |
|
|
|
1515 |
|
|
-- Normal case
|
1516 |
|
|
|
1517 |
|
|
else
|
1518 |
|
|
Loop_Node := New_Node (N_Loop_Statement, Token_Ptr);
|
1519 |
|
|
|
1520 |
|
|
if No (Loop_Name) then
|
1521 |
|
|
Created_Name :=
|
1522 |
|
|
Make_Identifier (Sloc (Loop_Node),
|
1523 |
|
|
Chars => Set_Loop_Block_Name ('L'));
|
1524 |
|
|
Set_Comes_From_Source (Created_Name, False);
|
1525 |
|
|
Set_Has_Created_Identifier (Loop_Node, True);
|
1526 |
|
|
Set_Identifier (Loop_Node, Created_Name);
|
1527 |
|
|
Scope.Table (Scope.Last).Labl := Created_Name;
|
1528 |
|
|
else
|
1529 |
|
|
Set_Identifier (Loop_Node, Loop_Name);
|
1530 |
|
|
end if;
|
1531 |
|
|
|
1532 |
|
|
TF_Loop;
|
1533 |
|
|
Set_Statements (Loop_Node, P_Sequence_Of_Statements (SS_Sreq));
|
1534 |
|
|
End_Statements (Loop_Node);
|
1535 |
|
|
Set_Iteration_Scheme (Loop_Node, Iter_Scheme_Node);
|
1536 |
|
|
Append_Elmt (Loop_Node, Label_List);
|
1537 |
|
|
return Loop_Node;
|
1538 |
|
|
end if;
|
1539 |
|
|
end P_For_Statement;
|
1540 |
|
|
|
1541 |
|
|
-- P_While_Statement
|
1542 |
|
|
|
1543 |
|
|
-- This procedure scans a loop statement with a WHILE iteration scheme
|
1544 |
|
|
|
1545 |
|
|
-- The caller has checked that the initial token is WHILE. The parameter
|
1546 |
|
|
-- is the node identifier for the block label if any (or is set to Empty
|
1547 |
|
|
-- if there is no block label).
|
1548 |
|
|
|
1549 |
|
|
-- Error recovery: cannot raise Error_Resync
|
1550 |
|
|
|
1551 |
|
|
function P_While_Statement (Loop_Name : Node_Id := Empty) return Node_Id is
|
1552 |
|
|
Loop_Node : Node_Id;
|
1553 |
|
|
Iter_Scheme_Node : Node_Id;
|
1554 |
|
|
Loop_While_Flag : Boolean;
|
1555 |
|
|
Created_Name : Node_Id;
|
1556 |
|
|
|
1557 |
|
|
begin
|
1558 |
|
|
Push_Scope_Stack;
|
1559 |
|
|
Scope.Table (Scope.Last).Labl := Loop_Name;
|
1560 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1561 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1562 |
|
|
Scope.Table (Scope.Last).Etyp := E_Loop;
|
1563 |
|
|
|
1564 |
|
|
Loop_While_Flag := (Prev_Token = Tok_Loop);
|
1565 |
|
|
Iter_Scheme_Node := New_Node (N_Iteration_Scheme, Token_Ptr);
|
1566 |
|
|
Scan; -- past WHILE
|
1567 |
|
|
Set_Condition (Iter_Scheme_Node, P_Condition);
|
1568 |
|
|
|
1569 |
|
|
-- The following is a special test so that a miswritten for loop such
|
1570 |
|
|
-- as "loop while I > 10;" is handled nicely, without making an extra
|
1571 |
|
|
-- entry in the scope stack. We don't bother to actually fix up the
|
1572 |
|
|
-- tree in this case since it's not worth the effort. Instead we just
|
1573 |
|
|
-- eat up the loop junk, leaving the entry for what now looks like an
|
1574 |
|
|
-- unmodified loop intact.
|
1575 |
|
|
|
1576 |
|
|
if Loop_While_Flag and then Token = Tok_Semicolon then
|
1577 |
|
|
Error_Msg_SC ("LOOP belongs here, not before WHILE");
|
1578 |
|
|
Pop_Scope_Stack;
|
1579 |
|
|
return Error;
|
1580 |
|
|
|
1581 |
|
|
-- Normal case
|
1582 |
|
|
|
1583 |
|
|
else
|
1584 |
|
|
Loop_Node := New_Node (N_Loop_Statement, Token_Ptr);
|
1585 |
|
|
TF_Loop;
|
1586 |
|
|
|
1587 |
|
|
if No (Loop_Name) then
|
1588 |
|
|
Created_Name :=
|
1589 |
|
|
Make_Identifier (Sloc (Loop_Node),
|
1590 |
|
|
Chars => Set_Loop_Block_Name ('L'));
|
1591 |
|
|
Set_Comes_From_Source (Created_Name, False);
|
1592 |
|
|
Set_Has_Created_Identifier (Loop_Node, True);
|
1593 |
|
|
Set_Identifier (Loop_Node, Created_Name);
|
1594 |
|
|
Scope.Table (Scope.Last).Labl := Created_Name;
|
1595 |
|
|
else
|
1596 |
|
|
Set_Identifier (Loop_Node, Loop_Name);
|
1597 |
|
|
end if;
|
1598 |
|
|
|
1599 |
|
|
Set_Statements (Loop_Node, P_Sequence_Of_Statements (SS_Sreq));
|
1600 |
|
|
End_Statements (Loop_Node);
|
1601 |
|
|
Set_Iteration_Scheme (Loop_Node, Iter_Scheme_Node);
|
1602 |
|
|
Append_Elmt (Loop_Node, Label_List);
|
1603 |
|
|
return Loop_Node;
|
1604 |
|
|
end if;
|
1605 |
|
|
end P_While_Statement;
|
1606 |
|
|
|
1607 |
|
|
---------------------------------------
|
1608 |
|
|
-- 5.5 Loop Parameter Specification --
|
1609 |
|
|
---------------------------------------
|
1610 |
|
|
|
1611 |
|
|
-- LOOP_PARAMETER_SPECIFICATION ::=
|
1612 |
|
|
-- DEFINING_IDENTIFIER in [reverse] DISCRETE_SUBTYPE_DEFINITION
|
1613 |
|
|
|
1614 |
|
|
-- Error recovery: cannot raise Error_Resync
|
1615 |
|
|
|
1616 |
|
|
function P_Loop_Parameter_Specification return Node_Id is
|
1617 |
|
|
Loop_Param_Specification_Node : Node_Id;
|
1618 |
|
|
|
1619 |
|
|
ID_Node : Node_Id;
|
1620 |
|
|
Scan_State : Saved_Scan_State;
|
1621 |
|
|
|
1622 |
|
|
begin
|
1623 |
|
|
Loop_Param_Specification_Node :=
|
1624 |
|
|
New_Node (N_Loop_Parameter_Specification, Token_Ptr);
|
1625 |
|
|
|
1626 |
|
|
Save_Scan_State (Scan_State);
|
1627 |
|
|
ID_Node := P_Defining_Identifier (C_In);
|
1628 |
|
|
Set_Defining_Identifier (Loop_Param_Specification_Node, ID_Node);
|
1629 |
|
|
|
1630 |
|
|
if Token = Tok_Left_Paren then
|
1631 |
|
|
Error_Msg_SC ("subscripted loop parameter not allowed");
|
1632 |
|
|
Restore_Scan_State (Scan_State);
|
1633 |
|
|
Discard_Junk_Node (P_Name);
|
1634 |
|
|
|
1635 |
|
|
elsif Token = Tok_Dot then
|
1636 |
|
|
Error_Msg_SC ("selected loop parameter not allowed");
|
1637 |
|
|
Restore_Scan_State (Scan_State);
|
1638 |
|
|
Discard_Junk_Node (P_Name);
|
1639 |
|
|
end if;
|
1640 |
|
|
|
1641 |
|
|
T_In;
|
1642 |
|
|
|
1643 |
|
|
if Token = Tok_Reverse then
|
1644 |
|
|
Scan; -- past REVERSE
|
1645 |
|
|
Set_Reverse_Present (Loop_Param_Specification_Node, True);
|
1646 |
|
|
end if;
|
1647 |
|
|
|
1648 |
|
|
Set_Discrete_Subtype_Definition
|
1649 |
|
|
(Loop_Param_Specification_Node, P_Discrete_Subtype_Definition);
|
1650 |
|
|
return Loop_Param_Specification_Node;
|
1651 |
|
|
|
1652 |
|
|
exception
|
1653 |
|
|
when Error_Resync =>
|
1654 |
|
|
return Error;
|
1655 |
|
|
end P_Loop_Parameter_Specification;
|
1656 |
|
|
|
1657 |
|
|
--------------------------
|
1658 |
|
|
-- 5.6 Block Statement --
|
1659 |
|
|
--------------------------
|
1660 |
|
|
|
1661 |
|
|
-- BLOCK_STATEMENT ::=
|
1662 |
|
|
-- [block_STATEMENT_IDENTIFIER:]
|
1663 |
|
|
-- [declare
|
1664 |
|
|
-- DECLARATIVE_PART]
|
1665 |
|
|
-- begin
|
1666 |
|
|
-- HANDLED_SEQUENCE_OF_STATEMENTS
|
1667 |
|
|
-- end [block_IDENTIFIER];
|
1668 |
|
|
|
1669 |
|
|
-- The parsing of block statements is handled by one of the two functions
|
1670 |
|
|
-- P_Declare_Statement or P_Begin_Statement depending on whether or not
|
1671 |
|
|
-- a declare section is present
|
1672 |
|
|
|
1673 |
|
|
-- P_Declare_Statement
|
1674 |
|
|
|
1675 |
|
|
-- This function parses a block statement with DECLARE present
|
1676 |
|
|
|
1677 |
|
|
-- The caller has checked that the initial token is DECLARE
|
1678 |
|
|
|
1679 |
|
|
-- Error recovery: cannot raise Error_Resync
|
1680 |
|
|
|
1681 |
|
|
function P_Declare_Statement
|
1682 |
|
|
(Block_Name : Node_Id := Empty)
|
1683 |
|
|
return Node_Id
|
1684 |
|
|
is
|
1685 |
|
|
Block_Node : Node_Id;
|
1686 |
|
|
Created_Name : Node_Id;
|
1687 |
|
|
|
1688 |
|
|
begin
|
1689 |
|
|
Block_Node := New_Node (N_Block_Statement, Token_Ptr);
|
1690 |
|
|
|
1691 |
|
|
Push_Scope_Stack;
|
1692 |
|
|
Scope.Table (Scope.Last).Etyp := E_Name;
|
1693 |
|
|
Scope.Table (Scope.Last).Lreq := Present (Block_Name);
|
1694 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1695 |
|
|
Scope.Table (Scope.Last).Labl := Block_Name;
|
1696 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1697 |
|
|
|
1698 |
|
|
Scan; -- past DECLARE
|
1699 |
|
|
|
1700 |
|
|
if No (Block_Name) then
|
1701 |
|
|
Created_Name :=
|
1702 |
|
|
Make_Identifier (Sloc (Block_Node),
|
1703 |
|
|
Chars => Set_Loop_Block_Name ('B'));
|
1704 |
|
|
Set_Comes_From_Source (Created_Name, False);
|
1705 |
|
|
Set_Has_Created_Identifier (Block_Node, True);
|
1706 |
|
|
Set_Identifier (Block_Node, Created_Name);
|
1707 |
|
|
Scope.Table (Scope.Last).Labl := Created_Name;
|
1708 |
|
|
else
|
1709 |
|
|
Set_Identifier (Block_Node, Block_Name);
|
1710 |
|
|
end if;
|
1711 |
|
|
|
1712 |
|
|
Append_Elmt (Block_Node, Label_List);
|
1713 |
|
|
Parse_Decls_Begin_End (Block_Node);
|
1714 |
|
|
return Block_Node;
|
1715 |
|
|
end P_Declare_Statement;
|
1716 |
|
|
|
1717 |
|
|
-- P_Begin_Statement
|
1718 |
|
|
|
1719 |
|
|
-- This function parses a block statement with no DECLARE present
|
1720 |
|
|
|
1721 |
|
|
-- The caller has checked that the initial token is BEGIN
|
1722 |
|
|
|
1723 |
|
|
-- Error recovery: cannot raise Error_Resync
|
1724 |
|
|
|
1725 |
|
|
function P_Begin_Statement
|
1726 |
|
|
(Block_Name : Node_Id := Empty)
|
1727 |
|
|
return Node_Id
|
1728 |
|
|
is
|
1729 |
|
|
Block_Node : Node_Id;
|
1730 |
|
|
Created_Name : Node_Id;
|
1731 |
|
|
|
1732 |
|
|
begin
|
1733 |
|
|
Block_Node := New_Node (N_Block_Statement, Token_Ptr);
|
1734 |
|
|
|
1735 |
|
|
Push_Scope_Stack;
|
1736 |
|
|
Scope.Table (Scope.Last).Etyp := E_Name;
|
1737 |
|
|
Scope.Table (Scope.Last).Lreq := Present (Block_Name);
|
1738 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1739 |
|
|
Scope.Table (Scope.Last).Labl := Block_Name;
|
1740 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1741 |
|
|
|
1742 |
|
|
if No (Block_Name) then
|
1743 |
|
|
Created_Name :=
|
1744 |
|
|
Make_Identifier (Sloc (Block_Node),
|
1745 |
|
|
Chars => Set_Loop_Block_Name ('B'));
|
1746 |
|
|
Set_Comes_From_Source (Created_Name, False);
|
1747 |
|
|
Set_Has_Created_Identifier (Block_Node, True);
|
1748 |
|
|
Set_Identifier (Block_Node, Created_Name);
|
1749 |
|
|
Scope.Table (Scope.Last).Labl := Created_Name;
|
1750 |
|
|
else
|
1751 |
|
|
Set_Identifier (Block_Node, Block_Name);
|
1752 |
|
|
end if;
|
1753 |
|
|
|
1754 |
|
|
Append_Elmt (Block_Node, Label_List);
|
1755 |
|
|
|
1756 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
1757 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
1758 |
|
|
Scan; -- past BEGIN
|
1759 |
|
|
Set_Handled_Statement_Sequence
|
1760 |
|
|
(Block_Node, P_Handled_Sequence_Of_Statements);
|
1761 |
|
|
End_Statements (Handled_Statement_Sequence (Block_Node));
|
1762 |
|
|
return Block_Node;
|
1763 |
|
|
end P_Begin_Statement;
|
1764 |
|
|
|
1765 |
|
|
-------------------------
|
1766 |
|
|
-- 5.7 Exit Statement --
|
1767 |
|
|
-------------------------
|
1768 |
|
|
|
1769 |
|
|
-- EXIT_STATEMENT ::=
|
1770 |
|
|
-- exit [loop_NAME] [when CONDITION];
|
1771 |
|
|
|
1772 |
|
|
-- The caller has checked that the initial token is EXIT
|
1773 |
|
|
|
1774 |
|
|
-- Error recovery: can raise Error_Resync
|
1775 |
|
|
|
1776 |
|
|
function P_Exit_Statement return Node_Id is
|
1777 |
|
|
Exit_Node : Node_Id;
|
1778 |
|
|
|
1779 |
|
|
function Missing_Semicolon_On_Exit return Boolean;
|
1780 |
|
|
-- This function deals with the following specialized situation
|
1781 |
|
|
--
|
1782 |
|
|
-- when 'x' =>
|
1783 |
|
|
-- exit [identifier]
|
1784 |
|
|
-- when 'y' =>
|
1785 |
|
|
--
|
1786 |
|
|
-- This looks like a messed up EXIT WHEN, when in fact the problem
|
1787 |
|
|
-- is a missing semicolon. It is called with Token pointing to the
|
1788 |
|
|
-- WHEN token, and returns True if a semicolon is missing before
|
1789 |
|
|
-- the WHEN as in the above example.
|
1790 |
|
|
|
1791 |
|
|
-------------------------------
|
1792 |
|
|
-- Missing_Semicolon_On_Exit --
|
1793 |
|
|
-------------------------------
|
1794 |
|
|
|
1795 |
|
|
function Missing_Semicolon_On_Exit return Boolean is
|
1796 |
|
|
State : Saved_Scan_State;
|
1797 |
|
|
|
1798 |
|
|
begin
|
1799 |
|
|
if not Token_Is_At_Start_Of_Line then
|
1800 |
|
|
return False;
|
1801 |
|
|
|
1802 |
|
|
elsif Scope.Table (Scope.Last).Etyp /= E_Case then
|
1803 |
|
|
return False;
|
1804 |
|
|
|
1805 |
|
|
else
|
1806 |
|
|
Save_Scan_State (State);
|
1807 |
|
|
Scan; -- past WHEN
|
1808 |
|
|
Scan; -- past token after WHEN
|
1809 |
|
|
|
1810 |
|
|
if Token = Tok_Arrow then
|
1811 |
|
|
Restore_Scan_State (State);
|
1812 |
|
|
return True;
|
1813 |
|
|
else
|
1814 |
|
|
Restore_Scan_State (State);
|
1815 |
|
|
return False;
|
1816 |
|
|
end if;
|
1817 |
|
|
end if;
|
1818 |
|
|
end Missing_Semicolon_On_Exit;
|
1819 |
|
|
|
1820 |
|
|
-- Start of processing for P_Exit_Statement
|
1821 |
|
|
|
1822 |
|
|
begin
|
1823 |
|
|
Exit_Node := New_Node (N_Exit_Statement, Token_Ptr);
|
1824 |
|
|
Scan; -- past EXIT
|
1825 |
|
|
|
1826 |
|
|
if Token = Tok_Identifier then
|
1827 |
|
|
Set_Name (Exit_Node, P_Qualified_Simple_Name);
|
1828 |
|
|
|
1829 |
|
|
elsif Style_Check then
|
1830 |
|
|
-- This EXIT has no name, so check that
|
1831 |
|
|
-- the innermost loop is unnamed too.
|
1832 |
|
|
|
1833 |
|
|
Check_No_Exit_Name :
|
1834 |
|
|
for J in reverse 1 .. Scope.Last loop
|
1835 |
|
|
if Scope.Table (J).Etyp = E_Loop then
|
1836 |
|
|
if Present (Scope.Table (J).Labl)
|
1837 |
|
|
and then Comes_From_Source (Scope.Table (J).Labl)
|
1838 |
|
|
then
|
1839 |
|
|
-- Innermost loop in fact had a name, style check fails
|
1840 |
|
|
|
1841 |
|
|
Style.No_Exit_Name (Scope.Table (J).Labl);
|
1842 |
|
|
end if;
|
1843 |
|
|
|
1844 |
|
|
exit Check_No_Exit_Name;
|
1845 |
|
|
end if;
|
1846 |
|
|
end loop Check_No_Exit_Name;
|
1847 |
|
|
end if;
|
1848 |
|
|
|
1849 |
|
|
if Token = Tok_When and then not Missing_Semicolon_On_Exit then
|
1850 |
|
|
Scan; -- past WHEN
|
1851 |
|
|
Set_Condition (Exit_Node, P_Condition);
|
1852 |
|
|
|
1853 |
|
|
-- Allow IF instead of WHEN, giving error message
|
1854 |
|
|
|
1855 |
|
|
elsif Token = Tok_If then
|
1856 |
|
|
T_When;
|
1857 |
|
|
Scan; -- past IF used in place of WHEN
|
1858 |
|
|
Set_Condition (Exit_Node, P_Expression_No_Right_Paren);
|
1859 |
|
|
end if;
|
1860 |
|
|
|
1861 |
|
|
TF_Semicolon;
|
1862 |
|
|
return Exit_Node;
|
1863 |
|
|
end P_Exit_Statement;
|
1864 |
|
|
|
1865 |
|
|
-------------------------
|
1866 |
|
|
-- 5.8 Goto Statement --
|
1867 |
|
|
-------------------------
|
1868 |
|
|
|
1869 |
|
|
-- GOTO_STATEMENT ::= goto label_NAME;
|
1870 |
|
|
|
1871 |
|
|
-- The caller has checked that the initial token is GOTO (or TO in the
|
1872 |
|
|
-- error case where GO and TO were incorrectly separated).
|
1873 |
|
|
|
1874 |
|
|
-- Error recovery: can raise Error_Resync
|
1875 |
|
|
|
1876 |
|
|
function P_Goto_Statement return Node_Id is
|
1877 |
|
|
Goto_Node : Node_Id;
|
1878 |
|
|
|
1879 |
|
|
begin
|
1880 |
|
|
Goto_Node := New_Node (N_Goto_Statement, Token_Ptr);
|
1881 |
|
|
Scan; -- past GOTO (or TO)
|
1882 |
|
|
Set_Name (Goto_Node, P_Qualified_Simple_Name_Resync);
|
1883 |
|
|
Append_Elmt (Goto_Node, Goto_List);
|
1884 |
|
|
No_Constraint;
|
1885 |
|
|
TF_Semicolon;
|
1886 |
|
|
return Goto_Node;
|
1887 |
|
|
end P_Goto_Statement;
|
1888 |
|
|
|
1889 |
|
|
---------------------------
|
1890 |
|
|
-- Parse_Decls_Begin_End --
|
1891 |
|
|
---------------------------
|
1892 |
|
|
|
1893 |
|
|
-- This function parses the construct:
|
1894 |
|
|
|
1895 |
|
|
-- DECLARATIVE_PART
|
1896 |
|
|
-- begin
|
1897 |
|
|
-- HANDLED_SEQUENCE_OF_STATEMENTS
|
1898 |
|
|
-- end [NAME];
|
1899 |
|
|
|
1900 |
|
|
-- The caller has built the scope stack entry, and created the node to
|
1901 |
|
|
-- whose Declarations and Handled_Statement_Sequence fields are to be
|
1902 |
|
|
-- set. On return these fields are filled in (except in the case of a
|
1903 |
|
|
-- task body, where the handled statement sequence is optional, and may
|
1904 |
|
|
-- thus be Empty), and the scan is positioned past the End sequence.
|
1905 |
|
|
|
1906 |
|
|
-- If the BEGIN is missing, then the parent node is used to help construct
|
1907 |
|
|
-- an appropriate missing BEGIN message. Possibilities for the parent are:
|
1908 |
|
|
|
1909 |
|
|
-- N_Block_Statement declare block
|
1910 |
|
|
-- N_Entry_Body entry body
|
1911 |
|
|
-- N_Package_Body package body (begin part optional)
|
1912 |
|
|
-- N_Subprogram_Body procedure or function body
|
1913 |
|
|
-- N_Task_Body task body
|
1914 |
|
|
|
1915 |
|
|
-- Note: in the case of a block statement, there is definitely a DECLARE
|
1916 |
|
|
-- present (because a Begin statement without a DECLARE is handled by the
|
1917 |
|
|
-- P_Begin_Statement procedure, which does not call Parse_Decls_Begin_End.
|
1918 |
|
|
|
1919 |
|
|
-- Error recovery: cannot raise Error_Resync
|
1920 |
|
|
|
1921 |
|
|
procedure Parse_Decls_Begin_End (Parent : Node_Id) is
|
1922 |
|
|
Body_Decl : Node_Id;
|
1923 |
|
|
Body_Sloc : Source_Ptr;
|
1924 |
|
|
Decls : List_Id;
|
1925 |
|
|
Decl : Node_Id;
|
1926 |
|
|
Parent_Nkind : Node_Kind;
|
1927 |
|
|
Spec_Node : Node_Id;
|
1928 |
|
|
HSS : Node_Id;
|
1929 |
|
|
|
1930 |
|
|
procedure Missing_Begin (Msg : String);
|
1931 |
|
|
-- Called to post a missing begin message. In the normal case this is
|
1932 |
|
|
-- posted at the start of the current token. A special case arises when
|
1933 |
|
|
-- P_Declarative_Items has previously found a missing begin, in which
|
1934 |
|
|
-- case we replace the original error message.
|
1935 |
|
|
|
1936 |
|
|
procedure Set_Null_HSS (Parent : Node_Id);
|
1937 |
|
|
-- Construct an empty handled statement sequence and install in Parent
|
1938 |
|
|
-- Leaves HSS set to reference the newly constructed statement sequence.
|
1939 |
|
|
|
1940 |
|
|
-------------------
|
1941 |
|
|
-- Missing_Begin --
|
1942 |
|
|
-------------------
|
1943 |
|
|
|
1944 |
|
|
procedure Missing_Begin (Msg : String) is
|
1945 |
|
|
begin
|
1946 |
|
|
if Missing_Begin_Msg = No_Error_Msg then
|
1947 |
|
|
Error_Msg_BC (Msg);
|
1948 |
|
|
else
|
1949 |
|
|
Change_Error_Text (Missing_Begin_Msg, Msg);
|
1950 |
|
|
|
1951 |
|
|
-- Purge any messages issued after than, since a missing begin
|
1952 |
|
|
-- can cause a lot of havoc, and it is better not to dump these
|
1953 |
|
|
-- cascaded messages on the user.
|
1954 |
|
|
|
1955 |
|
|
Purge_Messages (Get_Location (Missing_Begin_Msg), Prev_Token_Ptr);
|
1956 |
|
|
end if;
|
1957 |
|
|
end Missing_Begin;
|
1958 |
|
|
|
1959 |
|
|
------------------
|
1960 |
|
|
-- Set_Null_HSS --
|
1961 |
|
|
------------------
|
1962 |
|
|
|
1963 |
|
|
procedure Set_Null_HSS (Parent : Node_Id) is
|
1964 |
|
|
Null_Stm : Node_Id;
|
1965 |
|
|
|
1966 |
|
|
begin
|
1967 |
|
|
Null_Stm :=
|
1968 |
|
|
Make_Null_Statement (Token_Ptr);
|
1969 |
|
|
Set_Comes_From_Source (Null_Stm, False);
|
1970 |
|
|
|
1971 |
|
|
HSS :=
|
1972 |
|
|
Make_Handled_Sequence_Of_Statements (Token_Ptr,
|
1973 |
|
|
Statements => New_List (Null_Stm));
|
1974 |
|
|
Set_Comes_From_Source (HSS, False);
|
1975 |
|
|
|
1976 |
|
|
Set_Handled_Statement_Sequence (Parent, HSS);
|
1977 |
|
|
end Set_Null_HSS;
|
1978 |
|
|
|
1979 |
|
|
-- Start of processing for Parse_Decls_Begin_End
|
1980 |
|
|
|
1981 |
|
|
begin
|
1982 |
|
|
Decls := P_Declarative_Part;
|
1983 |
|
|
|
1984 |
|
|
-- Check for misplacement of later vs basic declarations in Ada 83
|
1985 |
|
|
|
1986 |
|
|
if Ada_Version = Ada_83 then
|
1987 |
|
|
Decl := First (Decls);
|
1988 |
|
|
|
1989 |
|
|
-- Loop through sequence of basic declarative items
|
1990 |
|
|
|
1991 |
|
|
Outer : while Present (Decl) loop
|
1992 |
|
|
if Nkind (Decl) /= N_Subprogram_Body
|
1993 |
|
|
and then Nkind (Decl) /= N_Package_Body
|
1994 |
|
|
and then Nkind (Decl) /= N_Task_Body
|
1995 |
|
|
and then Nkind (Decl) not in N_Body_Stub
|
1996 |
|
|
then
|
1997 |
|
|
Next (Decl);
|
1998 |
|
|
|
1999 |
|
|
-- Once a body is encountered, we only allow later declarative
|
2000 |
|
|
-- items. The inner loop checks the rest of the list.
|
2001 |
|
|
|
2002 |
|
|
else
|
2003 |
|
|
Body_Sloc := Sloc (Decl);
|
2004 |
|
|
|
2005 |
|
|
Inner : while Present (Decl) loop
|
2006 |
|
|
if Nkind (Decl) not in N_Later_Decl_Item
|
2007 |
|
|
and then Nkind (Decl) /= N_Pragma
|
2008 |
|
|
then
|
2009 |
|
|
if Ada_Version = Ada_83 then
|
2010 |
|
|
Error_Msg_Sloc := Body_Sloc;
|
2011 |
|
|
Error_Msg_N
|
2012 |
|
|
("(Ada 83) decl cannot appear after body#", Decl);
|
2013 |
|
|
end if;
|
2014 |
|
|
end if;
|
2015 |
|
|
|
2016 |
|
|
Next (Decl);
|
2017 |
|
|
end loop Inner;
|
2018 |
|
|
end if;
|
2019 |
|
|
end loop Outer;
|
2020 |
|
|
end if;
|
2021 |
|
|
|
2022 |
|
|
-- Here is where we deal with the case of IS used instead of semicolon.
|
2023 |
|
|
-- Specifically, if the last declaration in the declarative part is a
|
2024 |
|
|
-- subprogram body still marked as having a bad IS, then this is where
|
2025 |
|
|
-- we decide that the IS should really have been a semicolon and that
|
2026 |
|
|
-- the body should have been a declaration. Note that if the bad IS
|
2027 |
|
|
-- had turned out to be OK (i.e. a decent begin/end was found for it),
|
2028 |
|
|
-- then the Bad_Is_Detected flag would have been reset by now.
|
2029 |
|
|
|
2030 |
|
|
Body_Decl := Last (Decls);
|
2031 |
|
|
|
2032 |
|
|
if Present (Body_Decl)
|
2033 |
|
|
and then Nkind (Body_Decl) = N_Subprogram_Body
|
2034 |
|
|
and then Bad_Is_Detected (Body_Decl)
|
2035 |
|
|
then
|
2036 |
|
|
-- OK, we have the case of a bad IS, so we need to fix up the tree.
|
2037 |
|
|
-- What we have now is a subprogram body with attached declarations
|
2038 |
|
|
-- and a possible statement sequence.
|
2039 |
|
|
|
2040 |
|
|
-- First step is to take the declarations that were part of the bogus
|
2041 |
|
|
-- subprogram body and append them to the outer declaration chain.
|
2042 |
|
|
-- In other words we append them past the body (which we will later
|
2043 |
|
|
-- convert into a declaration).
|
2044 |
|
|
|
2045 |
|
|
Append_List (Declarations (Body_Decl), Decls);
|
2046 |
|
|
|
2047 |
|
|
-- Now take the handled statement sequence of the bogus body and
|
2048 |
|
|
-- set it as the statement sequence for the outer construct. Note
|
2049 |
|
|
-- that it may be empty (we specially allowed a missing BEGIN for
|
2050 |
|
|
-- a subprogram body marked as having a bad IS -- see below).
|
2051 |
|
|
|
2052 |
|
|
Set_Handled_Statement_Sequence (Parent,
|
2053 |
|
|
Handled_Statement_Sequence (Body_Decl));
|
2054 |
|
|
|
2055 |
|
|
-- Next step is to convert the old body node to a declaration node
|
2056 |
|
|
|
2057 |
|
|
Spec_Node := Specification (Body_Decl);
|
2058 |
|
|
Change_Node (Body_Decl, N_Subprogram_Declaration);
|
2059 |
|
|
Set_Specification (Body_Decl, Spec_Node);
|
2060 |
|
|
|
2061 |
|
|
-- Final step is to put the declarations for the parent where
|
2062 |
|
|
-- they belong, and then fall through the IF to scan out the
|
2063 |
|
|
-- END statements.
|
2064 |
|
|
|
2065 |
|
|
Set_Declarations (Parent, Decls);
|
2066 |
|
|
|
2067 |
|
|
-- This is the normal case (i.e. any case except the bad IS case)
|
2068 |
|
|
-- If we have a BEGIN, then scan out the sequence of statements, and
|
2069 |
|
|
-- also reset the expected column for the END to match the BEGIN.
|
2070 |
|
|
|
2071 |
|
|
else
|
2072 |
|
|
Set_Declarations (Parent, Decls);
|
2073 |
|
|
|
2074 |
|
|
if Token = Tok_Begin then
|
2075 |
|
|
if Style_Check then
|
2076 |
|
|
Style.Check_Indentation;
|
2077 |
|
|
end if;
|
2078 |
|
|
|
2079 |
|
|
Error_Msg_Col := Scope.Table (Scope.Last).Ecol;
|
2080 |
|
|
|
2081 |
|
|
if RM_Column_Check
|
2082 |
|
|
and then Token_Is_At_Start_Of_Line
|
2083 |
|
|
and then Start_Column /= Error_Msg_Col
|
2084 |
|
|
then
|
2085 |
|
|
Error_Msg_SC ("(style) BEGIN in wrong column, should be@");
|
2086 |
|
|
|
2087 |
|
|
else
|
2088 |
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
2089 |
|
|
end if;
|
2090 |
|
|
|
2091 |
|
|
Scope.Table (Scope.Last).Sloc := Token_Ptr;
|
2092 |
|
|
Scan; -- past BEGIN
|
2093 |
|
|
Set_Handled_Statement_Sequence (Parent,
|
2094 |
|
|
P_Handled_Sequence_Of_Statements);
|
2095 |
|
|
|
2096 |
|
|
-- No BEGIN present
|
2097 |
|
|
|
2098 |
|
|
else
|
2099 |
|
|
Parent_Nkind := Nkind (Parent);
|
2100 |
|
|
|
2101 |
|
|
-- A special check for the missing IS case. If we have a
|
2102 |
|
|
-- subprogram body that was marked as having a suspicious
|
2103 |
|
|
-- IS, and the current token is END, then we simply confirm
|
2104 |
|
|
-- the suspicion, and do not require a BEGIN to be present
|
2105 |
|
|
|
2106 |
|
|
if Parent_Nkind = N_Subprogram_Body
|
2107 |
|
|
and then Token = Tok_End
|
2108 |
|
|
and then Scope.Table (Scope.Last).Etyp = E_Suspicious_Is
|
2109 |
|
|
then
|
2110 |
|
|
Scope.Table (Scope.Last).Etyp := E_Bad_Is;
|
2111 |
|
|
|
2112 |
|
|
-- Otherwise BEGIN is not required for a package body, so we
|
2113 |
|
|
-- don't mind if it is missing, but we do construct a dummy
|
2114 |
|
|
-- one (so that we have somewhere to set End_Label).
|
2115 |
|
|
|
2116 |
|
|
-- However if we have something other than a BEGIN which
|
2117 |
|
|
-- looks like it might be statements, then we signal a missing
|
2118 |
|
|
-- BEGIN for these cases as well. We define "something which
|
2119 |
|
|
-- looks like it might be statements" as a token other than
|
2120 |
|
|
-- END, EOF, or a token which starts declarations.
|
2121 |
|
|
|
2122 |
|
|
elsif Parent_Nkind = N_Package_Body
|
2123 |
|
|
and then (Token = Tok_End
|
2124 |
|
|
or else Token = Tok_EOF
|
2125 |
|
|
or else Token in Token_Class_Declk)
|
2126 |
|
|
then
|
2127 |
|
|
Set_Null_HSS (Parent);
|
2128 |
|
|
|
2129 |
|
|
-- These are cases in which a BEGIN is required and not present
|
2130 |
|
|
|
2131 |
|
|
else
|
2132 |
|
|
Set_Null_HSS (Parent);
|
2133 |
|
|
|
2134 |
|
|
-- Prepare to issue error message
|
2135 |
|
|
|
2136 |
|
|
Error_Msg_Sloc := Scope.Table (Scope.Last).Sloc;
|
2137 |
|
|
Error_Msg_Node_1 := Scope.Table (Scope.Last).Labl;
|
2138 |
|
|
|
2139 |
|
|
-- Now issue appropriate message
|
2140 |
|
|
|
2141 |
|
|
if Parent_Nkind = N_Block_Statement then
|
2142 |
|
|
Missing_Begin ("missing BEGIN for DECLARE#!");
|
2143 |
|
|
|
2144 |
|
|
elsif Parent_Nkind = N_Entry_Body then
|
2145 |
|
|
Missing_Begin ("missing BEGIN for ENTRY#!");
|
2146 |
|
|
|
2147 |
|
|
elsif Parent_Nkind = N_Subprogram_Body then
|
2148 |
|
|
if Nkind (Specification (Parent))
|
2149 |
|
|
= N_Function_Specification
|
2150 |
|
|
then
|
2151 |
|
|
Missing_Begin ("missing BEGIN for function&#!");
|
2152 |
|
|
else
|
2153 |
|
|
Missing_Begin ("missing BEGIN for procedure&#!");
|
2154 |
|
|
end if;
|
2155 |
|
|
|
2156 |
|
|
-- The case for package body arises only when
|
2157 |
|
|
-- we have possible statement junk present.
|
2158 |
|
|
|
2159 |
|
|
elsif Parent_Nkind = N_Package_Body then
|
2160 |
|
|
Missing_Begin ("missing BEGIN for package body&#!");
|
2161 |
|
|
|
2162 |
|
|
else
|
2163 |
|
|
pragma Assert (Parent_Nkind = N_Task_Body);
|
2164 |
|
|
Missing_Begin ("missing BEGIN for task body&#!");
|
2165 |
|
|
end if;
|
2166 |
|
|
|
2167 |
|
|
-- Here we pick up the statements after the BEGIN that
|
2168 |
|
|
-- should have been present but was not. We don't insist
|
2169 |
|
|
-- on statements being present if P_Declarative_Part had
|
2170 |
|
|
-- already found a missing BEGIN, since it might have
|
2171 |
|
|
-- swallowed a lone statement into the declarative part.
|
2172 |
|
|
|
2173 |
|
|
if Missing_Begin_Msg /= No_Error_Msg
|
2174 |
|
|
and then Token = Tok_End
|
2175 |
|
|
then
|
2176 |
|
|
null;
|
2177 |
|
|
else
|
2178 |
|
|
Set_Handled_Statement_Sequence (Parent,
|
2179 |
|
|
P_Handled_Sequence_Of_Statements);
|
2180 |
|
|
end if;
|
2181 |
|
|
end if;
|
2182 |
|
|
end if;
|
2183 |
|
|
end if;
|
2184 |
|
|
|
2185 |
|
|
-- Here with declarations and handled statement sequence scanned
|
2186 |
|
|
|
2187 |
|
|
if Present (Handled_Statement_Sequence (Parent)) then
|
2188 |
|
|
End_Statements (Handled_Statement_Sequence (Parent));
|
2189 |
|
|
else
|
2190 |
|
|
End_Statements;
|
2191 |
|
|
end if;
|
2192 |
|
|
|
2193 |
|
|
-- We know that End_Statements removed an entry from the scope stack
|
2194 |
|
|
-- (because it is required to do so under all circumstances). We can
|
2195 |
|
|
-- therefore reference the entry it removed one past the stack top.
|
2196 |
|
|
-- What we are interested in is whether it was a case of a bad IS.
|
2197 |
|
|
|
2198 |
|
|
if Scope.Table (Scope.Last + 1).Etyp = E_Bad_Is then
|
2199 |
|
|
Error_Msg ("|IS should be "";""", Scope.Table (Scope.Last + 1).S_Is);
|
2200 |
|
|
Set_Bad_Is_Detected (Parent, True);
|
2201 |
|
|
end if;
|
2202 |
|
|
|
2203 |
|
|
end Parse_Decls_Begin_End;
|
2204 |
|
|
|
2205 |
|
|
-------------------------
|
2206 |
|
|
-- Set_Loop_Block_Name --
|
2207 |
|
|
-------------------------
|
2208 |
|
|
|
2209 |
|
|
function Set_Loop_Block_Name (L : Character) return Name_Id is
|
2210 |
|
|
begin
|
2211 |
|
|
Name_Buffer (1) := L;
|
2212 |
|
|
Name_Buffer (2) := '_';
|
2213 |
|
|
Name_Len := 2;
|
2214 |
|
|
Loop_Block_Count := Loop_Block_Count + 1;
|
2215 |
|
|
Add_Nat_To_Name_Buffer (Loop_Block_Count);
|
2216 |
|
|
return Name_Find;
|
2217 |
|
|
end Set_Loop_Block_Name;
|
2218 |
|
|
|
2219 |
|
|
---------------
|
2220 |
|
|
-- Then_Scan --
|
2221 |
|
|
---------------
|
2222 |
|
|
|
2223 |
|
|
procedure Then_Scan is
|
2224 |
|
|
begin
|
2225 |
|
|
TF_Then;
|
2226 |
|
|
|
2227 |
|
|
while Token = Tok_Then loop
|
2228 |
|
|
Error_Msg_SC ("redundant THEN");
|
2229 |
|
|
TF_Then;
|
2230 |
|
|
end loop;
|
2231 |
|
|
|
2232 |
|
|
if Token = Tok_And or else Token = Tok_Or then
|
2233 |
|
|
Error_Msg_SC ("unexpected logical operator");
|
2234 |
|
|
Scan; -- past logical operator
|
2235 |
|
|
|
2236 |
|
|
if (Prev_Token = Tok_And and then Token = Tok_Then)
|
2237 |
|
|
or else
|
2238 |
|
|
(Prev_Token = Tok_Or and then Token = Tok_Else)
|
2239 |
|
|
then
|
2240 |
|
|
Scan;
|
2241 |
|
|
end if;
|
2242 |
|
|
|
2243 |
|
|
Discard_Junk_Node (P_Expression);
|
2244 |
|
|
end if;
|
2245 |
|
|
|
2246 |
|
|
if Token = Tok_Then then
|
2247 |
|
|
Scan;
|
2248 |
|
|
end if;
|
2249 |
|
|
end Then_Scan;
|
2250 |
|
|
|
2251 |
|
|
end Ch5;
|