X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/720d742f8e74acf1ade85a7d39c02fa5b9528b5a..e89a22bfab22e4d2ee73be49dcb66b51f8d0e892:/src/lalr.h diff --git a/src/lalr.h b/src/lalr.h index 4f11cc51..55e01d8f 100644 --- a/src/lalr.h +++ b/src/lalr.h @@ -1,5 +1,5 @@ /* Compute look-ahead criteria for bison, - Copyright (C) 1984, 1986, 1989 Free Software Foundation, Inc. + Copyright 1984, 1986, 1989, 2000 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -21,6 +21,11 @@ #ifndef LALR_H_ # define LALR_H_ + +/* Import the definition of CORE, SHIFTS and REDUCTIONS. */ +# include "state.h" + + /* Compute how to make the finite state machine deterministic; find which rules need lookahead in each state, and which lookahead tokens they accept. */ @@ -30,25 +35,20 @@ void lalr PARAMS ((void)); /* lalr() builds these data structures. */ -/* goto_map, from_state and to_state --record each shift transition +/* GOTO_MAP, FROM_STATE and TO_STATE -- record each shift transition which accepts a variable (a nonterminal). - from_state[t] is the state number which a transition leads from and - to_state[t] is the state number it leads to. All the transitions - that accept a particular variable are grouped together and - goto_map[i - ntokens] is the index in from_state and to_state of - the first of them. */ + FROM_STATE[T] -- state number which a transition leads from. + TO_STATE[T] -- state number it leads to. + + All the transitions that accept a particular variable are grouped + together and GOTO_MAP[I - NTOKENS] is the index in FROM_STATE and + TO_STATE of the first of them. */ extern short *goto_map; extern short *from_state; extern short *to_state; -/* CONSISTENT[S] is nonzero if no lookahead is needed to decide what - to do in state S. */ - -extern char *consistent; - - /* LARULENO is a vector which records the rules that need lookahead in various states. The elements of LARULENO that apply to state S are those from LOOKAHEADS[S] through LOOKAHEADS[S+1]-1. Each element @@ -66,15 +66,36 @@ extern short *LAruleno; it is a conflict. */ extern unsigned *LA; +#define LA(Rule) (LA + (Rule) * tokensetsize) -extern int tokensetsize; -extern short *lookaheads; -extern short *accessing_symbol; -extern core **state_table; -extern shifts **shift_table; -extern reductions **reduction_table; +/* A structure decorating a state, with additional information. */ +typedef struct state_s +{ + /* A state. */ + core *state; + + /* Its accessing symbol. */ + short accessing_symbol; + + shifts *shifts; + reductions *reductions; + errs *errs; + + /* Nonzero if no lookahead is needed to decide what to do in state + S. */ + char consistent; + short lookaheads; +} state_t; +/* All the decorated states, indexed by the state number. Warning: + there is a state_TABLE in LR0.c, but it is different and static. + */ +extern state_t *state_table; + +extern int tokensetsize; +/* The number of lookaheads. */ +extern size_t nlookaheads; #endif /* !LALR_H_ */