-- Abstract : -- -- See spec. -- -- Copyright (C) 2017 - 2020 Free Software Foundation, Inc. -- -- This file is part of the WisiToken package. -- -- The WisiToken package is free software; you can redistribute it -- and/or modify it under terms of the GNU General Public License as -- published by the Free Software Foundation; either version 3, or -- (at your option) any later version. This library is distributed in -- the hope that it will be useful, but WITHOUT ANY WARRANTY; without -- even the implied warranty of MERCHAN- TABILITY or FITNESS FOR A -- PARTICULAR PURPOSE. -- -- As a special exception under Section 7 of GPL version 3, you are granted -- additional permissions described in the GCC Runtime Library Exception, -- version 3.1, as published by the Free Software Foundation. pragma License (Modified_GPL); with Ada.Containers; with Ada.Text_IO; with WisiToken.Generate; package body WisiToken.Generate.LR.LR1_Generate is function LR1_Goto_Transitions (Set : in LR1_Items.Item_Set; Symbol : in Token_ID; Has_Empty_Production : in Token_ID_Set; First_Terminal_Sequence : in Token_Sequence_Arrays.Vector; Grammar : in WisiToken.Productions.Prod_Arrays.Vector; Descriptor : in WisiToken.Descriptor) return LR1_Items.Item_Set is use all type Ada.Containers.Count_Type; use Token_ID_Arrays; use LR1_Items; Goto_Set : Item_Set; begin for Item of Set.Set loop if Item.Dot /= No_Index then declare Dot : constant Token_ID_Arrays.Cursor := Productions.Constant_Ref_RHS (Grammar, Item.Prod).Tokens.To_Cursor (Item.Dot); begin if Element (Dot) = Symbol and -- We don't need a state with dot after EOI in the -- accept production. EOI should only appear in the -- accept production. Symbol /= Descriptor.EOI_ID then Goto_Set.Set.Insert ((Item.Prod, To_Index (Next (Dot)), new Token_ID_Set'(Item.Lookaheads.all))); end if; end; end if; end loop; if Goto_Set.Set.Length > 0 then return Closure (Goto_Set, Has_Empty_Production, First_Terminal_Sequence, Grammar, Descriptor); else return Goto_Set; end if; end LR1_Goto_Transitions; function LR1_Item_Sets (Has_Empty_Production : in Token_ID_Set; First_Terminal_Sequence : in Token_Sequence_Arrays.Vector; Grammar : in WisiToken.Productions.Prod_Arrays.Vector; Descriptor : in WisiToken.Descriptor) return LR1_Items.Item_Set_List is use all type Ada.Containers.Count_Type; -- [dragon] algorithm 4.9 pg 231; figure 4.38 pg 232; procedure -- "items", with some optimizations. use LR1_Items; First_State_Index : constant State_Index := 0; C : LR1_Items.Item_Set_List; -- result C_Tree : LR1_Items.Item_Set_Trees.Tree; -- for fast find States_To_Check : State_Index_Queues.Queue; -- [dragon] specifies 'until no more items can be added', but we use -- a queue to avoid checking unecessary states. Ada LR1 has over -- 100,000 states, so this is a significant gain (reduced time from -- 600 seconds to 40). I : State_Index; Dot_IDs : Token_ID_Arrays.Vector; New_Item_Set : Item_Set := Closure ((Set => Item_Lists.To_List ((Prod => (Grammar.First_Index, 0), Dot => Grammar (Grammar.First_Index).RHSs (0).Tokens.First_Index, Lookaheads => new Token_ID_Set'(To_Lookahead (Descriptor.EOI_ID, Descriptor)))), Goto_List => <>, Dot_IDs => <>, State => First_State_Index), Has_Empty_Production, First_Terminal_Sequence, Grammar, Descriptor); Found_State : Unknown_State_Index; begin C.Set_First_Last (First_State_Index, First_State_Index - 1); Add (Grammar, New_Item_Set, C, C_Tree, Descriptor, Include_Lookaheads => True); States_To_Check.Put (First_State_Index); loop exit when States_To_Check.Is_Empty; I := States_To_Check.Get; if Trace_Generate_Table > Outline then Ada.Text_IO.Put ("Checking "); Put (Grammar, Descriptor, C (I), Show_Lookaheads => True, Show_Goto_List => True); end if; Dot_IDs := C (I).Dot_IDs; -- We can't iterate on C (I).Dot_IDs when the loop adds items to C; -- it might be reallocated to grow. for Symbol of Dot_IDs loop -- [dragon] has 'for each grammar symbol X', but LR1_Goto_Transitions -- rejects Symbol that is not in Dot_IDs, so we iterate over that. New_Item_Set := LR1_Goto_Transitions (C (I), Symbol, Has_Empty_Production, First_Terminal_Sequence, Grammar, Descriptor); if New_Item_Set.Set.Length > 0 then -- 'goto (I, X) not empty' Found_State := Find (New_Item_Set, C_Tree, Match_Lookaheads => True); -- 'not in C' if Found_State = Unknown_State then New_Item_Set.State := C.Last_Index + 1; States_To_Check.Put (New_Item_Set.State); Add (Grammar, New_Item_Set, C, C_Tree, Descriptor, Include_Lookaheads => True); if Trace_Generate_Table > Outline then Ada.Text_IO.Put_Line (" adding state" & Unknown_State_Index'Image (C.Last_Index) & ": from state" & Unknown_State_Index'Image (I) & " on " & Image (Symbol, Descriptor)); Put (Grammar, Descriptor, New_Item_Set, Show_Lookaheads => True); end if; C (I).Goto_List.Insert ((Symbol, C.Last_Index)); else -- If there's not already a goto entry between these two sets, create one. if not Is_In ((Symbol, Found_State), Goto_List => C (I).Goto_List) then if Trace_Generate_Table > Outline then Ada.Text_IO.Put_Line (" adding goto on " & Image (Symbol, Descriptor) & " to state" & Unknown_State_Index'Image (Found_State)); end if; C (I).Goto_List.Insert ((Symbol, Found_State)); end if; end if; end if; end loop; end loop; if Trace_Generate_Table > Outline then Ada.Text_IO.New_Line; end if; return C; end LR1_Item_Sets; procedure Add_Actions (Item_Sets : in LR1_Items.Item_Set_List; Grammar : in WisiToken.Productions.Prod_Arrays.Vector; Has_Empty_Production : in Token_ID_Set; First_Nonterm_Set : in Token_Array_Token_Set; Conflict_Counts : out Conflict_Count_Lists.List; Conflicts : out Conflict_Lists.List; Table : in out Parse_Table; Descriptor : in WisiToken.Descriptor) is -- Add actions for all Item_Sets to Table. begin for Item_Set of Item_Sets loop Add_Actions (Item_Set, Table, Grammar, Has_Empty_Production, First_Nonterm_Set, Conflict_Counts, Conflicts, Descriptor); end loop; if Trace_Generate_Table > Outline then Ada.Text_IO.New_Line; end if; end Add_Actions; function Generate (Grammar : in out WisiToken.Productions.Prod_Arrays.Vector; Descriptor : in WisiToken.Descriptor; Known_Conflicts : in Conflict_Lists.List := Conflict_Lists.Empty_List; McKenzie_Param : in McKenzie_Param_Type := Default_McKenzie_Param; Parse_Table_File_Name : in String := ""; Include_Extra : in Boolean := False; Ignore_Conflicts : in Boolean := False; Partial_Recursion : in Boolean := True) return Parse_Table_Ptr is use type Ada.Containers.Count_Type; Ignore_Unused_Tokens : constant Boolean := WisiToken.Trace_Generate_Table > Detail; Ignore_Unknown_Conflicts : constant Boolean := Ignore_Conflicts or WisiToken.Trace_Generate_Table > Detail; Unused_Tokens : constant Boolean := WisiToken.Generate.Check_Unused_Tokens (Descriptor, Grammar); Table : Parse_Table_Ptr; Nullable : constant Token_Array_Production_ID := WisiToken.Generate.Nullable (Grammar); Has_Empty_Production : constant Token_ID_Set := WisiToken.Generate.Has_Empty_Production (Nullable); Recursions : constant WisiToken.Generate.Recursions := (if Partial_Recursion then WisiToken.Generate.Compute_Partial_Recursion (Grammar, Descriptor) else WisiToken.Generate.Compute_Full_Recursion (Grammar, Descriptor)); Minimal_Terminal_Sequences : constant Minimal_Sequence_Array := Compute_Minimal_Terminal_Sequences (Descriptor, Grammar); Minimal_Terminal_First : constant Token_Array_Token_ID := Compute_Minimal_Terminal_First (Descriptor, Minimal_Terminal_Sequences); First_Nonterm_Set : constant Token_Array_Token_Set := WisiToken.Generate.First (Grammar, Has_Empty_Production, Descriptor.First_Terminal); First_Terminal_Sequence : constant Token_Sequence_Arrays.Vector := WisiToken.Generate.To_Terminal_Sequence_Array (First_Nonterm_Set, Descriptor); Item_Sets : constant LR1_Items.Item_Set_List := LR1_Item_Sets (Has_Empty_Production, First_Terminal_Sequence, Grammar, Descriptor); Conflict_Counts : Conflict_Count_Lists.List; Unknown_Conflicts : Conflict_Lists.List; Known_Conflicts_Edit : Conflict_Lists.List := Known_Conflicts; begin if Trace_Generate_Table + Trace_Generate_Minimal_Complete > Outline then Ada.Text_IO.New_Line; Ada.Text_IO.Put_Line ("LR1_Generate:"); if Trace_Generate_Table > Outline then Ada.Text_IO.Put_Line ("Item_Sets:"); LR1_Items.Put (Grammar, Descriptor, Item_Sets); end if; end if; Table := new Parse_Table (State_First => Item_Sets.First_Index, State_Last => Item_Sets.Last_Index, First_Terminal => Descriptor.First_Terminal, Last_Terminal => Descriptor.Last_Terminal, First_Nonterminal => Descriptor.First_Nonterminal, Last_Nonterminal => Descriptor.Last_Nonterminal); if McKenzie_Param = Default_McKenzie_Param then -- Descriminants in Default are wrong Table.McKenzie_Param := (First_Terminal => Descriptor.First_Terminal, Last_Terminal => Descriptor.Last_Terminal, First_Nonterminal => Descriptor.First_Nonterminal, Last_Nonterminal => Descriptor.Last_Nonterminal, Insert => (others => 0), Delete => (others => 0), Push_Back => (others => 0), Undo_Reduce => (others => 0), Minimal_Complete_Cost_Delta => Default_McKenzie_Param.Minimal_Complete_Cost_Delta, Fast_Forward => Default_McKenzie_Param.Fast_Forward, Matching_Begin => Default_McKenzie_Param.Matching_Begin, Ignore_Check_Fail => Default_McKenzie_Param.Ignore_Check_Fail, Task_Count => Default_McKenzie_Param.Task_Count, Check_Limit => Default_McKenzie_Param.Check_Limit, Check_Delta_Limit => Default_McKenzie_Param.Check_Delta_Limit, Enqueue_Limit => Default_McKenzie_Param.Enqueue_Limit); else Table.McKenzie_Param := McKenzie_Param; end if; Add_Actions (Item_Sets, Grammar, Has_Empty_Production, First_Nonterm_Set, Conflict_Counts, Unknown_Conflicts, Table.all, Descriptor); for State in Table.States'Range loop if Trace_Generate_Minimal_Complete > Extra then Ada.Text_IO.Put_Line ("Set_Minimal_Complete_Actions:" & State_Index'Image (State)); end if; WisiToken.Generate.LR.Set_Minimal_Complete_Actions (Table.States (State), LR1_Items.Filter (Item_Sets (State), Grammar, Descriptor, LR1_Items.In_Kernel'Access), Descriptor, Grammar, Nullable, Minimal_Terminal_Sequences, Minimal_Terminal_First); end loop; if Parse_Table_File_Name /= "" then WisiToken.Generate.LR.Put_Parse_Table (Table, Parse_Table_File_Name, "LR1", Grammar, Recursions, Item_Sets, Conflict_Counts, Descriptor, Include_Extra); end if; if Trace_Generate_Table > Outline then Ada.Text_IO.New_Line; Ada.Text_IO.Put_Line ("Has_Empty_Production: " & Image (Has_Empty_Production, Descriptor)); Ada.Text_IO.New_Line; Ada.Text_IO.Put_Line ("Minimal_Terminal_First:"); for ID in Minimal_Terminal_First'Range loop Ada.Text_IO.Put_Line (Image (ID, Descriptor) & " =>" & (if Minimal_Terminal_First (ID) = Invalid_Token_ID then "" else ' ' & Image (Minimal_Terminal_First (ID), Descriptor))); end loop; end if; Delete_Known (Unknown_Conflicts, Known_Conflicts_Edit); if Unknown_Conflicts.Length > 0 then Ada.Text_IO.Put_Line (Ada.Text_IO.Current_Error, "unknown conflicts:"); Put (Unknown_Conflicts, Ada.Text_IO.Current_Error, Descriptor); Ada.Text_IO.New_Line (Ada.Text_IO.Current_Error); WisiToken.Generate.Error := WisiToken.Generate.Error or not Ignore_Unknown_Conflicts; end if; if Known_Conflicts_Edit.Length > 0 then Ada.Text_IO.Put_Line (Ada.Text_IO.Current_Error, "excess known conflicts:"); Put (Known_Conflicts_Edit, Ada.Text_IO.Current_Error, Descriptor); Ada.Text_IO.New_Line (Ada.Text_IO.Current_Error); WisiToken.Generate.Error := WisiToken.Generate.Error or not Ignore_Unknown_Conflicts; end if; WisiToken.Generate.Error := WisiToken.Generate.Error or (Unused_Tokens and not Ignore_Unused_Tokens); return Table; end Generate; end WisiToken.Generate.LR.LR1_Generate;