From a70083a3ed3fc3f69e0bed00220614f9d8263994 Mon Sep 17 00:00:00 2001
From: Akim Demaille <akim@epita.fr>
Date: Mon, 2 Oct 2000 08:00:34 +0000
Subject: [PATCH] * src/reader.h: New file. Propagate its use instead of
tedious list of `extern' and prototypes. * src/reader.c: Formatting changes,
topological sort, s/register//.
---
ChangeLog | 9 +
src/Makefile.am | 2 +-
src/lalr.h | 5 +
src/main.c | 4 +-
src/output.c | 2 +-
src/reader.c | 1714 ++++++++++++++++++++++++-----------------------
src/reader.h | 39 ++
src/state.h | 250 +++----
8 files changed, 1044 insertions(+), 981 deletions(-)
create mode 100644 src/reader.h
diff --git a/ChangeLog b/ChangeLog
index c6550632..d9ea64fc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2000-10-02 Akim Demaille <akim@epita.fr>
+
+ * src/reader.h: New file.
+ Propagate its use instead of tedious list of `extern' and
+ prototypes.
+ * src/reader.c: Formatting changes, topological sort,
+ s/register//.
+
+
2000-10-02 Akim Demaille <akim@epita.fr>
* src/lex.h: Prototype `lex.c' exported functions.
diff --git a/src/Makefile.am b/src/Makefile.am
index 3dd5d6b1..ad5f69d2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -22,7 +22,7 @@ noinst_HEADERS = alloc.h closure.h complain.h \
derives.h \
files.h getargs.h gram.h lalr.h lex.h \
output.h state.h \
- symtab.h system.h types.h
+ reader.h symtab.h system.h types.h
data_DATA = bison.simple bison.hairy
diff --git a/src/lalr.h b/src/lalr.h
index 4f11cc51..c0abb2c7 100644
--- a/src/lalr.h
+++ b/src/lalr.h
@@ -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. */
diff --git a/src/main.c b/src/main.c
index 309e7fc5..e0879836 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,6 +26,8 @@
#include "complain.h"
#include "derives.h"
#include "output.h"
+#include "reader.h"
+#include "lalr.h"
#if 0 /* XXX currently unused. */
/* Nonzero means failure has been detected; don't write a parser file. */
@@ -40,12 +42,10 @@ extern void berror PARAMS((const char *));
extern char *printable_version PARAMS ((int));
extern void openfiles PARAMS ((void));
-extern void reader PARAMS ((void));
extern void reduce_grammar PARAMS ((void));
extern void set_nullable PARAMS ((void));
extern void free_nullable PARAMS ((void));
extern void generate_states PARAMS ((void));
-extern void lalr PARAMS ((void));
extern void initialize_conflicts PARAMS ((void));
extern void finalize_conflicts PARAMS ((void));
extern void verbose PARAMS ((void));
diff --git a/src/output.c b/src/output.c
index 1d1dbd2f..20b33618 100644
--- a/src/output.c
+++ b/src/output.c
@@ -99,6 +99,7 @@
#include "complain.h"
#include "output.h"
#include "lalr.h"
+#include "reader.h"
extern void berror PARAMS((const char *));
@@ -107,7 +108,6 @@ extern short *user_toknums;
extern int final_state;
extern errs **err_table;
-extern void reader_output_yylsp PARAMS ((FILE *));
static int nvectors;
static int nentries;
diff --git a/src/reader.c b/src/reader.c
index f12b017f..2263458a 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,5 +1,6 @@
/* Input parser for bison
- Copyright (C) 1984, 86, 89, 92, 98, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000
+ Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
@@ -19,14 +20,6 @@
Boston, MA 02111-1307, USA. */
-/* Read in the grammar specification and record it in the format
- described in gram.h. All guards are copied into the fguard file
- and all actions into faction, in each case forming the body of a C
- function (yyguard or yyaction) which contains a switch statement to
- decide which guard or action to execute.
-
- The entry point is reader (). */
-
#include "system.h"
#include "getargs.h"
#include "files.h"
@@ -68,46 +61,22 @@ extern int expected_conflicts;
extern char *token_buffer;
extern int maxtoken;
-extern void tabinit PARAMS((void));
-extern void free_symtab PARAMS((void));
-extern void open_extra_files PARAMS((void));
-extern char *printable_version PARAMS((int));
+extern void tabinit PARAMS ((void));
+extern void free_symtab PARAMS ((void));
+extern void open_extra_files PARAMS ((void));
+extern char *printable_version PARAMS ((int));
-typedef
- struct symbol_list
- {
- struct symbol_list *next;
- bucket *sym;
- bucket *ruleprec;
- }
- symbol_list;
-
-
-extern void reader PARAMS((void));
-extern void reader_output_yylsp PARAMS((FILE *));
-
-static void read_declarations PARAMS((void));
-static void copy_definition PARAMS((void));
-static void parse_token_decl PARAMS((int, int));
-static void parse_start_decl PARAMS((void));
-static void parse_type_decl PARAMS((void));
-static void parse_assoc_decl PARAMS((int));
-static void parse_union_decl PARAMS((void));
-static void parse_expect_decl PARAMS((void));
-static char *get_type_name PARAMS((int, symbol_list *));
-static void copy_guard PARAMS((symbol_list *, int));
-static void parse_thong_decl PARAMS((void));
-static void copy_action PARAMS((symbol_list *, int));
-static bucket *gensym PARAMS((void));
-static void readgram PARAMS((void));
-static void record_rule_line PARAMS((void));
-static void packsymbols PARAMS((void));
-static void output_token_defines PARAMS((FILE *));
-static void packgram PARAMS((void));
+typedef struct symbol_list
+{
+ struct symbol_list *next;
+ bucket *sym;
+ bucket *ruleprec;
+}
+symbol_list;
-#if 0
-static int get_type PARAMS((void));
-#endif
+
+extern void reader PARAMS ((void));
+extern void reader_output_yylsp PARAMS ((FILE *));
int lineno;
char **tags;
@@ -120,19 +89,19 @@ static bucket *startval;
they must be unions. */
static int value_components_used;
-static int typed; /* nonzero if %union has been seen. */
+static int typed; /* nonzero if %union has been seen. */
-static int lastprec; /* incremented for each %left, %right or %nonassoc seen */
+static int lastprec; /* incremented for each %left, %right or %nonassoc seen */
-static int gensym_count; /* incremented for each generated symbol */
+static int gensym_count; /* incremented for each generated symbol */
static bucket *errtoken;
static bucket *undeftoken;
/* Nonzero if any action or guard uses the @n construct. */
static int yylsp_needed;
-
+
/*===================\
| Low level lexing. |
\===================*/
@@ -161,9 +130,9 @@ skip_to_char (int target)
static inline int
read_signed_integer (FILE *stream)
{
- register int c = getc (stream);
- register int sign = 1;
- register int n = 0;
+ int c = getc (stream);
+ int sign = 1;
+ int n = 0;
if (c == '-')
{
@@ -207,7 +176,7 @@ copy_string (FILE *fin, FILE *fout, int match)
continue;
}
- putc(c, fout);
+ putc (c, fout);
if (c == '\\')
{
@@ -219,10 +188,10 @@ copy_string (FILE *fin, FILE *fout, int match)
lineno++;
}
- c = getc(fin);
+ c = getc (fin);
}
- putc(c, fout);
+ putc (c, fout);
}
@@ -233,10 +202,10 @@ copy_string (FILE *fin, FILE *fout, int match)
`---------------------------------------------------------------*/
static inline void
-copy_comment2 (FILE *in, FILE *out1, FILE* out2, int c)
+copy_comment2 (FILE *in, FILE *out1, FILE *out2, int c)
{
int cplus_comment;
- register int ended;
+ int ended;
cplus_comment = (c == '/');
putc (c, out1);
@@ -259,9 +228,9 @@ copy_comment2 (FILE *in, FILE *out1, FILE* out2, int c)
if (c == '/')
{
- putc(c, out1);
+ putc (c, out1);
if (out2)
- putc(c, out2);
+ putc (c, out2);
ended = 1;
}
}
@@ -301,206 +270,52 @@ copy_comment (FILE *fin, FILE *fout, int c)
}
-void
-reader (void)
-{
- start_flag = 0;
- startval = NULL; /* start symbol not specified yet. */
-
-#if 0
- /* initially assume token number translation not needed. */
- translations = 0;
-#endif
- /* Nowadays translations is always set to 1, since we give `error' a
- user-token-number to satisfy the Posix demand for YYERRCODE==256.
- */
- translations = 1;
-
- nsyms = 1;
- nvars = 0;
- nrules = 0;
- nitems = 0;
- rline_allocated = 10;
- rline = NEW2 (rline_allocated, short);
-
- typed = 0;
- lastprec = 0;
-
- gensym_count = 0;
-
- semantic_parser = 0;
- pure_parser = 0;
- yylsp_needed = 0;
-
- grammar = NULL;
-
- init_lex ();
- lineno = 1;
-
- /* Initialize the symbol table. */
- tabinit ();
- /* Construct the error token */
- errtoken = getsym ("error");
- errtoken->class = STOKEN;
- errtoken->user_token_number = 256; /* Value specified by POSIX. */
- /* Construct a token that represents all undefined literal tokens.
- It is always token number 2. */
- undeftoken = getsym ("$undefined.");
- undeftoken->class = STOKEN;
- undeftoken->user_token_number = 2;
-
- /* Read the declaration section. Copy %{ ... %} groups to FTABLE
- and FDEFINES file. Also notice any %token, %left, etc. found
- there. */
- putc ('\n', ftable);
- fprintf (ftable, "\
-/* %s, made from %s\n\
- by GNU bison %s. */\n\
-\n",
- noparserflag ? "Bison-generated parse tables" : "A Bison parser",
- infile,
- VERSION);
-
- fputs ("#define YYBISON 1 /* Identify Bison output. */\n\n", ftable);
- read_declarations ();
- /* Start writing the guard and action files, if they are needed. */
- output_headers ();
- /* Read in the grammar, build grammar in list form. Write out
- guards and actions. */
- readgram ();
- /* Now we know whether we need the line-number stack. If we do,
- write its type into the .tab.h file. */
- if (fdefines)
- reader_output_yylsp (fdefines);
- /* Write closing delimiters for actions and guards. */
- output_trailers ();
- if (yylsp_needed)
- fputs ("#define YYLSP_NEEDED\n\n", ftable);
- /* Assign the symbols their symbol numbers. Write #defines for the
- token symbols into FDEFINES if requested. */
- packsymbols ();
- /* Convert the grammar into the format described in gram.h. */
- packgram ();
- /* Free the symbol table data structure since symbols are now all
- referred to by symbol number. */
- free_symtab ();
-}
-
-void
-reader_output_yylsp (FILE *f)
-{
- if (yylsp_needed)
- fprintf(f, LTYPESTR);
-}
-
-/* Read from finput until `%%' is seen. Discard the `%%'. Handle any
- `%' declarations, and copy the contents of any `%{ ... %}' groups
- to fattrs. */
+/*-----------------------------------------------------------------.
+| FIN is pointing to a location (i.e., a `@'). Output to FOUT a |
+| reference to this location. STACK_OFFSET is the number of values |
+| in the current rule so far, which says where to find `$0' with |
+| respect to the top of the stack. |
+`-----------------------------------------------------------------*/
-static void
-read_declarations (void)
+static inline void
+copy_at (FILE *fin, FILE *fout, int stack_offset)
{
- register int c;
- register int tok;
+ int c;
- for (;;)
+ c = getc (fin);
+ if (c == '$')
{
- c = skip_white_space();
-
- if (c == '%')
- {
- tok = parse_percent_token();
-
- switch (tok)
- {
- case TWO_PERCENTS:
- return;
-
- case PERCENT_LEFT_CURLY:
- copy_definition();
- break;
-
- case TOKEN:
- parse_token_decl (STOKEN, SNTERM);
- break;
-
- case NTERM:
- parse_token_decl (SNTERM, STOKEN);
- break;
-
- case TYPE:
- parse_type_decl();
- break;
-
- case START:
- parse_start_decl();
- break;
-
- case UNION:
- parse_union_decl ();
- break;
-
- case EXPECT:
- parse_expect_decl();
- break;
- case THONG:
- parse_thong_decl();
- break;
- case LEFT:
- parse_assoc_decl(LEFT_ASSOC);
- break;
-
- case RIGHT:
- parse_assoc_decl(RIGHT_ASSOC);
- break;
-
- case NONASSOC:
- parse_assoc_decl(NON_ASSOC);
- break;
-
- case SEMANTIC_PARSER:
- if (semantic_parser == 0)
- {
- semantic_parser = 1;
- open_extra_files();
- }
- break;
-
- case PURE_PARSER:
- pure_parser = 1;
- break;
+ fprintf (fout, "yyloc");
+ yylsp_needed = 1;
+ }
+ else if (isdigit (c) || c == '-')
+ {
+ int n;
- case NOOP:
- break;
+ ungetc (c, fin);
+ n = read_signed_integer (fin);
- default:
- complain (_("unrecognized: %s"), token_buffer);
- skip_to_char('%');
- }
- }
- else if (c == EOF)
- fatal (_("no input grammar"));
- else
- {
- complain (_("unknown character: %s"), printable_version(c));
- skip_to_char('%');
- }
+ fprintf (fout, "yylsp[%d]", n - stack_offset);
+ yylsp_needed = 1;
}
+ else
+ complain (_("@%s is invalid"), printable_version (c));
}
-
-
-/* Copy the contents of a `%{ ... %}' into the definitions file. The
- `%{' has already been read. Return after reading the `%}'. */
+
+/*-------------------------------------------------------------------.
+| Copy the contents of a `%{ ... %}' into the definitions file. The |
+| `%{' has already been read. Return after reading the `%}'. |
+`-------------------------------------------------------------------*/
static void
copy_definition (void)
{
- register int c;
+ int c;
/* -1 while reading a character if prev char was %. */
- register int after_percent;
+ int after_percent;
if (!nolinesflag)
- fprintf(fattrs, "#line %d \"%s\"\n", lineno, infile);
+ fprintf (fattrs, "#line %d \"%s\"\n", lineno, infile);
after_percent = 0;
@@ -511,12 +326,12 @@ copy_definition (void)
switch (c)
{
case '\n':
- putc(c, fattrs);
+ putc (c, fattrs);
lineno++;
break;
case '%':
- after_percent = -1;
+ after_percent = -1;
break;
case '\'':
@@ -533,20 +348,19 @@ copy_definition (void)
break;
case EOF:
- fatal ("%s",
- _("unterminated `%{' definition"));
+ fatal ("%s", _("unterminated `%{' definition"));
default:
- putc(c, fattrs);
+ putc (c, fattrs);
}
- c = getc(finput);
+ c = getc (finput);
if (after_percent)
{
if (c == '}')
return;
- putc('%', fattrs);
+ putc ('%', fattrs);
}
after_percent = 0;
@@ -555,17 +369,18 @@ copy_definition (void)
}
-
-/* parse what comes after %token or %nterm.
-For %token, what_is is STOKEN and what_is_not is SNTERM.
-For %nterm, the arguments are reversed. */
+/*-----------------------------------------------------------------.
+| Parse what comes after %token or %nterm. For %token, what_is is |
+| STOKEN and what_is_not is SNTERM. For %nterm, the arguments are |
+| reversed. |
+`-----------------------------------------------------------------*/
static void
parse_token_decl (int what_is, int what_is_not)
{
- register int token = 0;
- register char *typename = 0;
- register struct bucket *symbol = NULL; /* pts to symbol being defined */
+ int token = 0;
+ char *typename = 0;
+ struct bucket *symbol = NULL; /* pts to symbol being defined */
int k;
for (;;)
@@ -577,7 +392,7 @@ parse_token_decl (int what_is, int what_is_not)
if (tmp_char == EOF)
fatal (_("Premature EOF after %s"), token_buffer);
- token = lex();
+ token = lex ();
if (token == COMMA)
{
symbol = NULL;
@@ -585,14 +400,13 @@ parse_token_decl (int what_is, int what_is_not)
}
if (token == TYPENAME)
{
- k = strlen(token_buffer);
- typename = NEW2(k + 1, char);
- strcpy(typename, token_buffer);
+ k = strlen (token_buffer);
+ typename = NEW2 (k + 1, char);
+ strcpy (typename, token_buffer);
value_components_used = 1;
symbol = NULL;
}
- else if (token == IDENTIFIER && *symval->tag == '\"'
- && symbol)
+ else if (token == IDENTIFIER && *symval->tag == '\"' && symbol)
{
translations = 1;
symval->class = STOKEN;
@@ -604,7 +418,7 @@ parse_token_decl (int what_is, int what_is_not)
symbol->alias = symval;
symbol = NULL;
- nsyms--; /* symbol and symval combined are only one symbol */
+ nsyms--; /* symbol and symval combined are only one symbol */
}
else if (token == IDENTIFIER)
{
@@ -621,102 +435,25 @@ parse_token_decl (int what_is, int what_is_not)
{
if (symbol->type_name == NULL)
symbol->type_name = typename;
- else if (strcmp(typename, symbol->type_name) != 0)
+ else if (strcmp (typename, symbol->type_name) != 0)
complain (_("type redeclaration for %s"), symbol->tag);
}
}
else if (symbol && token == NUMBER)
- {
+ {
symbol->user_token_number = numval;
translations = 1;
- }
+ }
else
{
complain (_("`%s' is invalid in %s"),
- token_buffer,
- (what_is == STOKEN) ? "%token" : "%nterm");
- skip_to_char('%');
+ token_buffer, (what_is == STOKEN) ? "%token" : "%nterm");
+ skip_to_char ('%');
}
}
}
-/* parse what comes after %thong
- the full syntax is
- %thong <type> token number literal
- the <type> or number may be omitted. The number specifies the
- user_token_number.
-
- Two symbols are entered in the table, one for the token symbol and
- one for the literal. Both are given the <type>, if any, from the declaration.
- The ->user_token_number of the first is SALIAS and the ->user_token_number
- of the second is set to the number, if any, from the declaration.
- The two symbols are linked via pointers in their ->alias fields.
-
- during output_defines_table, the symbol is reported
- thereafter, only the literal string is retained
- it is the literal string that is output to yytname
-*/
-
-static void
-parse_thong_decl (void)
-{
- register int token;
- register struct bucket *symbol;
- register char *typename = 0;
- int k, usrtoknum;
-
- translations = 1;
- token = lex(); /* fetch typename or first token */
- if (token == TYPENAME) {
- k = strlen(token_buffer);
- typename = NEW2(k + 1, char);
- strcpy(typename, token_buffer);
- value_components_used = 1;
- token = lex(); /* fetch first token */
- }
-
- /* process first token */
-
- if (token != IDENTIFIER)
- {
- complain (_("unrecognized item %s, expected an identifier"),
- token_buffer);
- skip_to_char('%');
- return;
- }
- symval->class = STOKEN;
- symval->type_name = typename;
- symval->user_token_number = SALIAS;
- symbol = symval;
-
- token = lex(); /* get number or literal string */
-
- if (token == NUMBER) {
- usrtoknum = numval;
- token = lex(); /* okay, did number, now get literal */
- }
- else usrtoknum = 0;
-
- /* process literal string token */
-
- if (token != IDENTIFIER || *symval->tag != '\"')
- {
- complain (_("expected string constant instead of %s"),
- token_buffer);
- skip_to_char('%');
- return;
- }
- symval->class = STOKEN;
- symval->type_name = typename;
- symval->user_token_number = usrtoknum;
-
- symval->alias = symbol;
- symbol->alias = symval;
-
- nsyms--; /* symbol and symval combined are only one symbol */
-}
-
/* Parse what comes after %start */
@@ -736,38 +473,76 @@ parse_start_decl (void)
-/* read in a %type declaration and record its information for get_type_name to access */
+/*--------------------------------------------------------------.
+| Get the data type (alternative in the union) of the value for |
+| symbol n in rule rule. |
+`--------------------------------------------------------------*/
-static void
-parse_type_decl (void)
+static char *
+get_type_name (int n, symbol_list * rule)
{
- register int k;
- register char *name;
+ int i;
+ symbol_list *rp;
- if (lex() != TYPENAME)
+ if (n < 0)
{
- complain ("%s", _("%type declaration has no <typename>"));
- skip_to_char('%');
- return;
+ complain (_("invalid $ value"));
+ return NULL;
}
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
+ rp = rule;
+ i = 0;
- for (;;)
+ while (i < n)
{
- register int t;
- int tmp_char = ungetc (skip_white_space (), finput);
-
- if (tmp_char == '%')
- return;
- if (tmp_char == EOF)
- fatal (_("Premature EOF after %s"), token_buffer);
-
- t = lex();
-
- switch (t)
+ rp = rp->next;
+ if (rp == NULL || rp->sym == NULL)
+ {
+ complain (_("invalid $ value"));
+ return NULL;
+ }
+ i++;
+ }
+
+ return rp->sym->type_name;
+}
+
+
+/*-----------------------------------------------------------.
+| read in a %type declaration and record its information for |
+| get_type_name to access |
+`-----------------------------------------------------------*/
+
+static void
+parse_type_decl (void)
+{
+ int k;
+ char *name;
+
+ if (lex () != TYPENAME)
+ {
+ complain ("%s", _("%type declaration has no <typename>"));
+ skip_to_char ('%');
+ return;
+ }
+
+ k = strlen (token_buffer);
+ name = NEW2 (k + 1, char);
+ strcpy (name, token_buffer);
+
+ for (;;)
+ {
+ int t;
+ int tmp_char = ungetc (skip_white_space (), finput);
+
+ if (tmp_char == '%')
+ return;
+ if (tmp_char == EOF)
+ fatal (_("Premature EOF after %s"), token_buffer);
+
+ t = lex ();
+
+ switch (t)
{
case COMMA:
@@ -777,7 +552,7 @@ parse_type_decl (void)
case IDENTIFIER:
if (symval->type_name == NULL)
symval->type_name = name;
- else if (strcmp(name, symval->type_name) != 0)
+ else if (strcmp (name, symval->type_name) != 0)
complain (_("type redeclaration for %s"), symval->tag);
break;
@@ -785,7 +560,7 @@ parse_type_decl (void)
default:
complain (_("invalid %%type declaration due to item: %s"),
token_buffer);
- skip_to_char('%');
+ skip_to_char ('%');
}
}
}
@@ -798,15 +573,15 @@ parse_type_decl (void)
static void
parse_assoc_decl (int assoc)
{
- register int k;
- register char *name = NULL;
- register int prev = 0;
+ int k;
+ char *name = NULL;
+ int prev = 0;
- lastprec++; /* Assign a new precedence level, never 0. */
+ lastprec++; /* Assign a new precedence level, never 0. */
for (;;)
{
- register int t;
+ int t;
int tmp_char = ungetc (skip_white_space (), finput);
if (tmp_char == '%')
@@ -814,15 +589,15 @@ parse_assoc_decl (int assoc)
if (tmp_char == EOF)
fatal (_("Premature EOF after %s"), token_buffer);
- t = lex();
+ t = lex ();
switch (t)
{
case TYPENAME:
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
+ k = strlen (token_buffer);
+ name = NEW2 (k + 1, char);
+ strcpy (name, token_buffer);
break;
case COMMA:
@@ -837,26 +612,27 @@ parse_assoc_decl (int assoc)
complain (_("symbol %s redefined"), symval->tag);
symval->class = STOKEN;
if (name)
- { /* record the type, if one is specified */
+ { /* record the type, if one is specified */
if (symval->type_name == NULL)
symval->type_name = name;
- else if (strcmp(name, symval->type_name) != 0)
+ else if (strcmp (name, symval->type_name) != 0)
complain (_("type redeclaration for %s"), symval->tag);
}
break;
case NUMBER:
if (prev == IDENTIFIER)
- {
+ {
symval->user_token_number = numval;
translations = 1;
- }
- else
- {
- complain (_("invalid text (%s) - number should be after identifier"),
- token_buffer);
- skip_to_char('%');
- }
+ }
+ else
+ {
+ complain (_
+ ("invalid text (%s) - number should be after identifier"),
+token_buffer);
+ skip_to_char ('%');
+ }
break;
case SEMICOLON:
@@ -864,7 +640,7 @@ parse_assoc_decl (int assoc)
default:
complain (_("unexpected item: %s"), token_buffer);
- skip_to_char('%');
+ skip_to_char ('%');
}
prev = t;
@@ -881,8 +657,8 @@ parse_assoc_decl (int assoc)
static void
parse_union_decl (void)
{
- register int c;
- register int count = 0;
+ int c;
+ int count = 0;
if (typed)
complain (_("multiple %s declarations"), "%union");
@@ -936,7 +712,7 @@ parse_union_decl (void)
/* JF don't choke on trailing semi */
c = skip_white_space ();
if (c != ';')
- ungetc (c,finput);
+ ungetc (c, finput);
return;
}
}
@@ -951,20 +727,20 @@ parse_union_decl (void)
static void
parse_expect_decl (void)
{
- register int c;
- register int count;
+ int c;
+ int count;
char buffer[20];
- c = getc(finput);
+ c = getc (finput);
while (c == ' ' || c == '\t')
- c = getc(finput);
+ c = getc (finput);
count = 0;
while (c >= '0' && c <= '9')
{
if (count < 20)
buffer[count++] = c;
- c = getc(finput);
+ c = getc (finput);
}
buffer[count] = 0;
@@ -975,236 +751,199 @@ parse_expect_decl (void)
expected_conflicts = atoi (buffer);
}
-/* that's all of parsing the declaration section */
-
-/* FIN is pointing to a location (i.e., a `@'). Output to FOUT
- a reference to this location. STACK_OFFSET is the number of values
- in the current rule so far, which says where to find `$0' with
- respect to the top of the stack. */
-static inline void
-copy_at (FILE *fin, FILE *fout, int stack_offset)
+
+/*-------------------------------------------------------------------.
+| Parse what comes after %thong. the full syntax is |
+| |
+| %thong <type> token number literal |
+| |
+| the <type> or number may be omitted. The number specifies the |
+| user_token_number. |
+| |
+| Two symbols are entered in the table, one for the token symbol and |
+| one for the literal. Both are given the <type>, if any, from the |
+| declaration. The ->user_token_number of the first is SALIAS and |
+| the ->user_token_number of the second is set to the number, if |
+| any, from the declaration. The two symbols are linked via |
+| pointers in their ->alias fields. |
+| |
+| During OUTPUT_DEFINES_TABLE, the symbol is reported thereafter, |
+| only the literal string is retained it is the literal string that |
+| is output to yytname |
+`-------------------------------------------------------------------*/
+
+static void
+parse_thong_decl (void)
{
- int c;
+ int token;
+ struct bucket *symbol;
+ char *typename = 0;
+ int k, usrtoknum;
- c = getc (fin);
- if (c == '$')
+ translations = 1;
+ token = lex (); /* fetch typename or first token */
+ if (token == TYPENAME)
{
- fprintf (fout, "yyloc");
- yylsp_needed = 1;
+ k = strlen (token_buffer);
+ typename = NEW2 (k + 1, char);
+ strcpy (typename, token_buffer);
+ value_components_used = 1;
+ token = lex (); /* fetch first token */
}
- else if (isdigit(c) || c == '-')
- {
- int n;
- ungetc (c, fin);
- n = read_signed_integer (fin);
+ /* process first token */
- fprintf (fout, "yylsp[%d]", n - stack_offset);
- yylsp_needed = 1;
+ if (token != IDENTIFIER)
+ {
+ complain (_("unrecognized item %s, expected an identifier"),
+ token_buffer);
+ skip_to_char ('%');
+ return;
}
- else
- complain (_("@%s is invalid"), printable_version (c));
-}
-
+ symval->class = STOKEN;
+ symval->type_name = typename;
+ symval->user_token_number = SALIAS;
+ symbol = symval;
-/* Get the data type (alternative in the union) of the value for
- symbol n in rule rule. */
+ token = lex (); /* get number or literal string */
-static char *
-get_type_name (int n, symbol_list *rule)
-{
- register int i;
- register symbol_list *rp;
-
- if (n < 0)
+ if (token == NUMBER)
{
- complain (_("invalid $ value"));
- return NULL;
+ usrtoknum = numval;
+ token = lex (); /* okay, did number, now get literal */
}
+ else
+ usrtoknum = 0;
- rp = rule;
- i = 0;
+ /* process literal string token */
- while (i < n)
+ if (token != IDENTIFIER || *symval->tag != '\"')
{
- rp = rp->next;
- if (rp == NULL || rp->sym == NULL)
- {
- complain (_("invalid $ value"));
- return NULL;
- }
- i++;
+ complain (_("expected string constant instead of %s"), token_buffer);
+ skip_to_char ('%');
+ return;
}
+ symval->class = STOKEN;
+ symval->type_name = typename;
+ symval->user_token_number = usrtoknum;
- return rp->sym->type_name;
-}
-
+ symval->alias = symbol;
+ symbol->alias = symval;
+ nsyms--; /* symbol and symval combined are only one symbol */
+}
-/* After `%guard' is seen in the input file, copy the actual guard
- into the guards file. If the guard is followed by an action, copy
- that into the actions file. STACK_OFFSET is the number of values
- in the current rule so far, which says where to find `$0' with
- respect to the top of the stack, for the simple parser in which the
- stack is not popped until after the guard is run. */
+/*----------------------------------------------------------------.
+| Read from finput until `%%' is seen. Discard the `%%'. Handle |
+| any `%' declarations, and copy the contents of any `%{ ... %}' |
+| groups to fattrs. |
+`----------------------------------------------------------------*/
static void
-copy_guard (symbol_list *rule, int stack_offset)
+read_declarations (void)
{
- register int c;
- register int n;
- register int count;
- register char *type_name;
- int brace_flag = 0;
-
- /* offset is always 0 if parser has already popped the stack pointer */
- if (semantic_parser) stack_offset = 0;
-
- fprintf(fguard, "\ncase %d:\n", nrules);
- if (!nolinesflag)
- fprintf (fguard, "#line %d \"%s\"\n", lineno, infile);
- putc('{', fguard);
-
- count = 0;
- c = getc(finput);
+ int c;
+ int tok;
- while (brace_flag ? (count > 0) : (c != ';'))
+ for (;;)
{
- switch (c)
- {
- case '\n':
- putc(c, fguard);
- lineno++;
- break;
+ c = skip_white_space ();
- case '{':
- putc(c, fguard);
- brace_flag = 1;
- count++;
- break;
+ if (c == '%')
+ {
+ tok = parse_percent_token ();
- case '}':
- putc(c, fguard);
- if (count > 0)
- count--;
- else
+ switch (tok)
{
- complain (_("unmatched %s"), "`}'");
- c = getc(finput); /* skip it */
- }
- break;
+ case TWO_PERCENTS:
+ return;
- case '\'':
- case '"':
- copy_string (finput, fguard, c);
- break;
+ case PERCENT_LEFT_CURLY:
+ copy_definition ();
+ break;
- case '/':
- putc (c, fguard);
- c = getc (finput);
- if (c != '*' && c != '/')
- continue;
- copy_comment (finput, fguard, c);
- break;
+ case TOKEN:
+ parse_token_decl (STOKEN, SNTERM);
+ break;
- case '$':
- c = getc(finput);
- type_name = NULL;
+ case NTERM:
+ parse_token_decl (SNTERM, STOKEN);
+ break;
- if (c == '<')
- {
- register char *cp = token_buffer;
+ case TYPE:
+ parse_type_decl ();
+ break;
- while ((c = getc(finput)) != '>' && c > 0)
- {
- if (cp == token_buffer + maxtoken)
- cp = grow_token_buffer(cp);
+ case START:
+ parse_start_decl ();
+ break;
- *cp++ = c;
- }
- *cp = 0;
- type_name = token_buffer;
+ case UNION:
+ parse_union_decl ();
+ break;
- c = getc(finput);
- }
+ case EXPECT:
+ parse_expect_decl ();
+ break;
+ case THONG:
+ parse_thong_decl ();
+ break;
+ case LEFT:
+ parse_assoc_decl (LEFT_ASSOC);
+ break;
- if (c == '$')
- {
- fprintf(fguard, "yyval");
- if (!type_name)
- type_name = rule->sym->type_name;
- if (type_name)
- fprintf(fguard, ".%s", type_name);
- if(!type_name && typed)
- complain (_("$$ of `%s' has no declared type"),
- rule->sym->tag);
- }
- else if (isdigit(c) || c == '-')
- {
- ungetc (c, finput);
- n = read_signed_integer (finput);
- c = getc (finput);
+ case RIGHT:
+ parse_assoc_decl (RIGHT_ASSOC);
+ break;
- if (!type_name && n > 0)
- type_name = get_type_name(n, rule);
+ case NONASSOC:
+ parse_assoc_decl (NON_ASSOC);
+ break;
- fprintf(fguard, "yyvsp[%d]", n - stack_offset);
- if (type_name)
- fprintf(fguard, ".%s", type_name);
- if (!type_name && typed)
- complain (_("$%d of `%s' has no declared type"),
- n, rule->sym->tag);
- continue;
- }
- else
- complain (_("$%s is invalid"), printable_version (c));
- break;
+ case SEMANTIC_PARSER:
+ if (semantic_parser == 0)
+ {
+ semantic_parser = 1;
+ open_extra_files ();
+ }
+ break;
- case '@':
- copy_at (finput, fguard, stack_offset);
- break;
+ case PURE_PARSER:
+ pure_parser = 1;
+ break;
- case EOF:
- fatal ("%s",
- _("unterminated %guard clause"));
+ case NOOP:
+ break;
- default:
- putc (c, fguard);
+ default:
+ complain (_("unrecognized: %s"), token_buffer);
+ skip_to_char ('%');
+ }
+ }
+ else if (c == EOF)
+ fatal (_("no input grammar"));
+ else
+ {
+ complain (_("unknown character: %s"), printable_version (c));
+ skip_to_char ('%');
}
-
- if (c != '}' || count != 0)
- c = getc(finput);
- }
-
- c = skip_white_space();
-
- fprintf(fguard, ";\n break;}");
- if (c == '{')
- copy_action (rule, stack_offset);
- else if (c == '=')
- {
- c = getc(finput); /* why not skip_white_space -wjh */
- if (c == '{')
- copy_action (rule, stack_offset);
}
- else
- ungetc(c, finput);
}
-
-
-
-/* Assuming that a `{' has just been seen, copy everything up to the
- matching `}' into the actions file. STACK_OFFSET is the number of
- values in the current rule so far, which says where to find `$0'
- with respect to the top of the stack. */
+
+/*-------------------------------------------------------------------.
+| Assuming that a `{' has just been seen, copy everything up to the |
+| matching `}' into the actions file. STACK_OFFSET is the number of |
+| values in the current rule so far, which says where to find `$0' |
+| with respect to the top of the stack. |
+`-------------------------------------------------------------------*/
static void
-copy_action (symbol_list *rule, int stack_offset)
+copy_action (symbol_list * rule, int stack_offset)
{
- register int c;
- register int n;
- register int count;
- register char *type_name;
+ int c;
+ int n;
+ int count;
+ char *type_name;
/* offset is always 0 if parser has already popped the stack pointer */
if (semantic_parser)
@@ -1216,21 +955,21 @@ copy_action (symbol_list *rule, int stack_offset)
putc ('{', faction);
count = 1;
- c = getc(finput);
+ c = getc (finput);
while (count > 0)
{
while (c != '}')
- {
- switch (c)
+ {
+ switch (c)
{
case '\n':
- putc(c, faction);
+ putc (c, faction);
lineno++;
break;
case '{':
- putc(c, faction);
+ putc (c, faction);
count++;
break;
@@ -1248,17 +987,17 @@ copy_action (symbol_list *rule, int stack_offset)
break;
case '$':
- c = getc(finput);
+ c = getc (finput);
type_name = NULL;
if (c == '<')
{
- register char *cp = token_buffer;
+ char *cp = token_buffer;
- while ((c = getc(finput)) != '>' && c > 0)
+ while ((c = getc (finput)) != '>' && c > 0)
{
if (cp == token_buffer + maxtoken)
- cp = grow_token_buffer(cp);
+ cp = grow_token_buffer (cp);
*cp++ = c;
}
@@ -1266,32 +1005,32 @@ copy_action (symbol_list *rule, int stack_offset)
type_name = token_buffer;
value_components_used = 1;
- c = getc(finput);
+ c = getc (finput);
}
if (c == '$')
{
- fprintf(faction, "yyval");
+ fprintf (faction, "yyval");
if (!type_name)
- type_name = get_type_name(0, rule);
+ type_name = get_type_name (0, rule);
if (type_name)
- fprintf(faction, ".%s", type_name);
- if(!type_name && typed)
+ fprintf (faction, ".%s", type_name);
+ if (!type_name && typed)
complain (_("$$ of `%s' has no declared type"),
rule->sym->tag);
}
- else if (isdigit(c) || c == '-')
+ else if (isdigit (c) || c == '-')
{
ungetc (c, finput);
- n = read_signed_integer(finput);
- c = getc(finput);
+ n = read_signed_integer (finput);
+ c = getc (finput);
if (!type_name && n > 0)
- type_name = get_type_name(n, rule);
+ type_name = get_type_name (n, rule);
- fprintf(faction, "yyvsp[%d]", n - stack_offset);
+ fprintf (faction, "yyvsp[%d]", n - stack_offset);
if (type_name)
- fprintf(faction, ".%s", type_name);
- if(!type_name && typed)
+ fprintf (faction, ".%s", type_name);
+ if (!type_name && typed)
complain (_("$%d of `%s' has no declared type"),
n, rule->sym->tag);
continue;
@@ -1309,73 +1048,297 @@ copy_action (symbol_list *rule, int stack_offset)
fatal (_("unmatched %s"), "`{'");
default:
- putc(c, faction);
+ putc (c, faction);
+ }
+
+ c = getc (finput);
+ }
+
+ /* above loop exits when c is '}' */
+
+ if (--count)
+ {
+ putc (c, faction);
+ c = getc (finput);
+ }
+ }
+
+ fprintf (faction, ";\n break;}");
+}
+
+/*-------------------------------------------------------------------.
+| After `%guard' is seen in the input file, copy the actual guard |
+| into the guards file. If the guard is followed by an action, copy |
+| that into the actions file. STACK_OFFSET is the number of values |
+| in the current rule so far, which says where to find `$0' with |
+| respect to the top of the stack, for the simple parser in which |
+| the stack is not popped until after the guard is run. |
+`-------------------------------------------------------------------*/
+
+static void
+copy_guard (symbol_list * rule, int stack_offset)
+{
+ int c;
+ int n;
+ int count;
+ char *type_name;
+ int brace_flag = 0;
+
+ /* offset is always 0 if parser has already popped the stack pointer */
+ if (semantic_parser)
+ stack_offset = 0;
+
+ fprintf (fguard, "\ncase %d:\n", nrules);
+ if (!nolinesflag)
+ fprintf (fguard, "#line %d \"%s\"\n", lineno, infile);
+ putc ('{', fguard);
+
+ count = 0;
+ c = getc (finput);
+
+ while (brace_flag ? (count > 0) : (c != ';'))
+ {
+ switch (c)
+ {
+ case '\n':
+ putc (c, fguard);
+ lineno++;
+ break;
+
+ case '{':
+ putc (c, fguard);
+ brace_flag = 1;
+ count++;
+ break;
+
+ case '}':
+ putc (c, fguard);
+ if (count > 0)
+ count--;
+ else
+ {
+ complain (_("unmatched %s"), "`}'");
+ c = getc (finput); /* skip it */
+ }
+ break;
+
+ case '\'':
+ case '"':
+ copy_string (finput, fguard, c);
+ break;
+
+ case '/':
+ putc (c, fguard);
+ c = getc (finput);
+ if (c != '*' && c != '/')
+ continue;
+ copy_comment (finput, fguard, c);
+ break;
+
+ case '$':
+ c = getc (finput);
+ type_name = NULL;
+
+ if (c == '<')
+ {
+ char *cp = token_buffer;
+
+ while ((c = getc (finput)) != '>' && c > 0)
+ {
+ if (cp == token_buffer + maxtoken)
+ cp = grow_token_buffer (cp);
+
+ *cp++ = c;
+ }
+ *cp = 0;
+ type_name = token_buffer;
+
+ c = getc (finput);
+ }
+
+ if (c == '$')
+ {
+ fprintf (fguard, "yyval");
+ if (!type_name)
+ type_name = rule->sym->type_name;
+ if (type_name)
+ fprintf (fguard, ".%s", type_name);
+ if (!type_name && typed)
+ complain (_("$$ of `%s' has no declared type"),
+ rule->sym->tag);
+ }
+ else if (isdigit (c) || c == '-')
+ {
+ ungetc (c, finput);
+ n = read_signed_integer (finput);
+ c = getc (finput);
+
+ if (!type_name && n > 0)
+ type_name = get_type_name (n, rule);
+
+ fprintf (fguard, "yyvsp[%d]", n - stack_offset);
+ if (type_name)
+ fprintf (fguard, ".%s", type_name);
+ if (!type_name && typed)
+ complain (_("$%d of `%s' has no declared type"),
+ n, rule->sym->tag);
+ continue;
}
+ else
+ complain (_("$%s is invalid"), printable_version (c));
+ break;
- c = getc(finput);
- }
+ case '@':
+ copy_at (finput, fguard, stack_offset);
+ break;
- /* above loop exits when c is '}' */
+ case EOF:
+ fatal ("%s", _("unterminated %guard clause"));
- if (--count)
- {
- putc(c, faction);
- c = getc(finput);
+ default:
+ putc (c, fguard);
}
+
+ if (c != '}' || count != 0)
+ c = getc (finput);
}
- fprintf(faction, ";\n break;}");
+ c = skip_white_space ();
+
+ fprintf (fguard, ";\n break;}");
+ if (c == '{')
+ copy_action (rule, stack_offset);
+ else if (c == '=')
+ {
+ c = getc (finput); /* why not skip_white_space -wjh */
+ if (c == '{')
+ copy_action (rule, stack_offset);
+ }
+ else
+ ungetc (c, finput);
}
+
+
+static void
+record_rule_line (void)
+{
+ /* Record each rule's source line number in rline table. */
+ if (nrules >= rline_allocated)
+ {
+ rline_allocated = nrules * 2;
+ rline = (short *) xrealloc ((char *) rline,
+ rline_allocated * sizeof (short));
+ }
+ rline[nrules] = lineno;
+}
-/* generate a dummy symbol, a nonterminal,
-whose name cannot conflict with the user's names. */
+/*-------------------------------------------------------------------.
+| Generate a dummy symbol, a nonterminal, whose name cannot conflict |
+| with the user's names. |
+`-------------------------------------------------------------------*/
static bucket *
gensym (void)
{
- register bucket *sym;
+ bucket *sym;
sprintf (token_buffer, "@%d", ++gensym_count);
- sym = getsym(token_buffer);
+ sym = getsym (token_buffer);
sym->class = SNTERM;
sym->value = nvars++;
return sym;
}
-/* Parse the input grammar into a one symbol_list structure.
-Each rule is represented by a sequence of symbols: the left hand side
-followed by the contents of the right hand side, followed by a null pointer
-instead of a symbol to terminate the rule.
-The next symbol is the lhs of the following rule.
+#if 0
+/*------------------------------------------------------------------.
+| read in a %type declaration and record its information for |
+| get_type_name to access. This is unused. It is only called from |
+| the #if 0 part of readgram |
+`------------------------------------------------------------------*/
+
+static int
+get_type (void)
+{
+ int k;
+ int t;
+ char *name;
+
+ t = lex ();
+
+ if (t != TYPENAME)
+ {
+ complain (_("invalid %s declaration"), "%type");
+ return t;
+ }
+
+ k = strlen (token_buffer);
+ name = NEW2 (k + 1, char);
+ strcpy (name, token_buffer);
+
+ for (;;)
+ {
+ t = lex ();
+
+ switch (t)
+ {
+ case SEMICOLON:
+ return lex ();
+
+ case COMMA:
+ break;
+
+ case IDENTIFIER:
+ if (symval->type_name == NULL)
+ symval->type_name = name;
+ else if (strcmp (name, symval->type_name) != 0)
+ complain (_("type redeclaration for %s"), symval->tag);
+
+ break;
+
+ default:
+ return t;
+ }
+ }
+}
-All guards and actions are copied out to the appropriate files,
-labelled by the rule number they apply to. */
+#endif
+
+/*------------------------------------------------------------------.
+| Parse the input grammar into a one symbol_list structure. Each |
+| rule is represented by a sequence of symbols: the left hand side |
+| followed by the contents of the right hand side, followed by a |
+| null pointer instead of a symbol to terminate the rule. The next |
+| symbol is the lhs of the following rule. |
+| |
+| All guards and actions are copied out to the appropriate files, |
+| labelled by the rule number they apply to. |
+`------------------------------------------------------------------*/
static void
readgram (void)
{
- register int t;
- register bucket *lhs = NULL;
- register symbol_list *p;
- register symbol_list *p1;
- register bucket *bp;
+ int t;
+ bucket *lhs = NULL;
+ symbol_list *p;
+ symbol_list *p1;
+ bucket *bp;
- symbol_list *crule; /* points to first symbol_list of current rule. */
- /* its symbol is the lhs of the rule. */
- symbol_list *crule1; /* points to the symbol_list preceding crule. */
+ symbol_list *crule; /* points to first symbol_list of current rule. */
+ /* its symbol is the lhs of the rule. */
+ symbol_list *crule1; /* points to the symbol_list preceding crule. */
p1 = NULL;
- t = lex();
+ t = lex ();
while (t != TWO_PERCENTS && t != ENDFILE)
{
if (t == IDENTIFIER || t == BAR)
{
- register int actionflag = 0;
- int rulelength = 0; /* number of symbols in rhs of this rule so far */
+ int actionflag = 0;
+ int rulelength = 0; /* number of symbols in rhs of this rule so far */
int xactions = 0; /* JF for error checking */
bucket *first_rhs = 0;
@@ -1389,11 +1352,11 @@ readgram (void)
start_flag = 1;
}
- t = lex();
+ t = lex ();
if (t != COLON)
{
complain (_("ill-formed rule: initial symbol not followed by colon"));
- unlex(t);
+ unlex (t);
}
}
@@ -1409,7 +1372,7 @@ readgram (void)
record_rule_line ();
- p = NEW(symbol_list);
+ p = NEW (symbol_list);
p->sym = lhs;
crule1 = p1;
@@ -1436,48 +1399,50 @@ readgram (void)
for (;;)
{
- t = lex();
+ t = lex ();
if (t == PREC)
{
- t = lex();
+ t = lex ();
crule->ruleprec = symval;
- t = lex();
+ t = lex ();
}
- if (! (t == IDENTIFIER || t == LEFT_CURLY)) break;
+ if (!(t == IDENTIFIER || t == LEFT_CURLY))
+ break;
/* If next token is an identifier, see if a colon follows it.
- If one does, exit this rule now. */
+ If one does, exit this rule now. */
if (t == IDENTIFIER)
{
- register bucket *ssave;
- register int t1;
+ bucket *ssave;
+ int t1;
ssave = symval;
- t1 = lex();
- unlex(t1);
+ t1 = lex ();
+ unlex (t1);
symval = ssave;
- if (t1 == COLON) break;
+ if (t1 == COLON)
+ break;
- if(!first_rhs) /* JF */
+ if (!first_rhs) /* JF */
first_rhs = symval;
/* Not followed by colon =>
process as part of this rule's rhs. */
}
/* If we just passed an action, that action was in the middle
- of a rule, so make a dummy rule to reduce it to a
- non-terminal. */
+ of a rule, so make a dummy rule to reduce it to a
+ non-terminal. */
if (actionflag)
{
- register bucket *sdummy;
+ bucket *sdummy;
/* Since the action was written out with this rule's */
/* number, we must give the new rule this number */
/* by inserting the new rule before it. */
/* Make a dummy nonterminal, a gensym. */
- sdummy = gensym();
+ sdummy = gensym ();
/* Make a new rule, whose body is empty,
before the current one, so that the action
@@ -1485,18 +1450,19 @@ readgram (void)
nrules++;
nitems++;
record_rule_line ();
- p = NEW(symbol_list);
+ p = NEW (symbol_list);
if (crule1)
crule1->next = p;
- else grammar = p;
+ else
+ grammar = p;
p->sym = sdummy;
- crule1 = NEW(symbol_list);
+ crule1 = NEW (symbol_list);
p->next = crule1;
crule1->next = crule;
/* insert the dummy generated by that rule into this rule. */
nitems++;
- p = NEW(symbol_list);
+ p = NEW (symbol_list);
p->sym = sdummy;
p1->next = p;
p1 = p;
@@ -1507,72 +1473,72 @@ readgram (void)
if (t == IDENTIFIER)
{
nitems++;
- p = NEW(symbol_list);
+ p = NEW (symbol_list);
p->sym = symval;
p1->next = p;
p1 = p;
}
- else /* handle an action. */
+ else /* handle an action. */
{
- copy_action(crule, rulelength);
+ copy_action (crule, rulelength);
actionflag = 1;
xactions++; /* JF */
}
rulelength++;
- } /* end of read rhs of rule */
+ } /* end of read rhs of rule */
/* Put an empty link in the list to mark the end of this rule */
- p = NEW(symbol_list);
+ p = NEW (symbol_list);
p1->next = p;
p1 = p;
if (t == PREC)
{
complain (_("two @prec's in a row"));
- t = lex();
+ t = lex ();
crule->ruleprec = symval;
- t = lex();
+ t = lex ();
}
if (t == GUARD)
{
- if (! semantic_parser)
+ if (!semantic_parser)
complain ("%s",
- _("%guard present but %semantic_parser not specified"));
+ _
+ ("%guard present but %semantic_parser not specified"));
- copy_guard(crule, rulelength);
- t = lex();
+ copy_guard (crule, rulelength);
+ t = lex ();
}
else if (t == LEFT_CURLY)
{
- /* This case never occurs -wjh */
+ /* This case never occurs -wjh */
if (actionflag)
complain (_("two actions at end of one rule"));
- copy_action(crule, rulelength);
+ copy_action (crule, rulelength);
actionflag = 1;
xactions++; /* -wjh */
- t = lex();
+ t = lex ();
}
/* If $$ is being set in default way, report if any type
mismatch. */
else if (!xactions
- && first_rhs
- && lhs->type_name != first_rhs->type_name)
+ && first_rhs && lhs->type_name != first_rhs->type_name)
{
if (lhs->type_name == 0
|| first_rhs->type_name == 0
- || strcmp(lhs->type_name,first_rhs->type_name))
+ || strcmp (lhs->type_name, first_rhs->type_name))
complain (_("type clash (`%s' `%s') on default action"),
lhs->type_name ? lhs->type_name : "",
- first_rhs->type_name ? first_rhs->type_name : "");
+ first_rhs->type_name ? first_rhs->type_name : "");
}
/* Warn if there is no default for $$ but we need one. */
else if (!xactions && !first_rhs && lhs->type_name != 0)
complain (_("empty rule for typed nonterminal, and no action"));
if (t == SEMICOLON)
- t = lex();
+ t = lex ();
}
#if 0
- /* these things can appear as alternatives to rules. */
+ /* these things can appear as alternatives to rules. */
/* NO, they cannot.
a) none of the documentation allows them
b) most of them scan forward until finding a next %
@@ -1580,39 +1546,39 @@ readgram (void)
*/
else if (t == TOKEN)
{
- parse_token_decl(STOKEN, SNTERM);
- t = lex();
+ parse_token_decl (STOKEN, SNTERM);
+ t = lex ();
}
else if (t == NTERM)
{
- parse_token_decl(SNTERM, STOKEN);
- t = lex();
+ parse_token_decl (SNTERM, STOKEN);
+ t = lex ();
}
else if (t == TYPE)
{
- t = get_type();
+ t = get_type ();
}
else if (t == UNION)
{
- parse_union_decl();
- t = lex();
+ parse_union_decl ();
+ t = lex ();
}
else if (t == EXPECT)
{
- parse_expect_decl();
- t = lex();
+ parse_expect_decl ();
+ t = lex ();
}
else if (t == START)
{
- parse_start_decl();
- t = lex();
+ parse_start_decl ();
+ t = lex ();
}
#endif
else
{
complain (_("invalid input: %s"), token_buffer);
- t = lex();
+ t = lex ();
}
}
@@ -1624,15 +1590,15 @@ readgram (void)
if (nrules == 0)
fatal (_("no rules in the input grammar"));
- if (typed == 0 /* JF put out same default YYSTYPE as YACC does */
+ if (typed == 0 /* JF put out same default YYSTYPE as YACC does */
&& !value_components_used)
{
/* We used to use `unsigned long' as YYSTYPE on MSDOS,
- but it seems better to be consistent.
- Most programs should declare their own type anyway. */
- fprintf(fattrs, "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
+ but it seems better to be consistent.
+ Most programs should declare their own type anyway. */
+ fprintf (fattrs, "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
if (fdefines)
- fprintf(fdefines, "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
+ fprintf (fdefines, "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
}
/* Report any undefined symbols and consider them nonterminals. */
@@ -1640,103 +1606,90 @@ readgram (void)
for (bp = firstsymbol; bp; bp = bp->next)
if (bp->class == SUNKNOWN)
{
- complain (_("symbol %s is used, but is not defined as a token and has no rules"),
- bp->tag);
+ complain (_
+ ("symbol %s is used, but is not defined as a token and has no rules"),
+bp->tag);
bp->class = SNTERM;
bp->value = nvars++;
}
ntokens = nsyms - nvars;
}
-
+
+/*--------------------------------------------------------------.
+| For named tokens, but not literal ones, define the name. The |
+| value is the user token number. |
+`--------------------------------------------------------------*/
static void
-record_rule_line (void)
-{
- /* Record each rule's source line number in rline table. */
-
- if (nrules >= rline_allocated)
- {
- rline_allocated = nrules * 2;
- rline = (short *) xrealloc ((char *) rline,
- rline_allocated * sizeof (short));
- }
- rline[nrules] = lineno;
-}
-
-
-#if 0
-/* read in a %type declaration and record its information for get_type_name to access */
-/* this is unused. it is only called from the #if 0 part of readgram */
-static int
-get_type (void)
+output_token_defines (FILE *file)
{
- register int k;
- register int t;
- register char *name;
-
- t = lex();
-
- if (t != TYPENAME)
- {
- complain (_("invalid %s declaration"), "%type");
- return t;
- }
-
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
+ bucket *bp;
+ char *cp, *symbol;
+ char c;
- for (;;)
+ for (bp = firstsymbol; bp; bp = bp->next)
{
- t = lex();
-
- switch (t)
+ symbol = bp->tag; /* get symbol */
+
+ if (bp->value >= ntokens)
+ continue;
+ if (bp->user_token_number == SALIAS)
+ continue;
+ if ('\'' == *symbol)
+ continue; /* skip literal character */
+ if (bp == errtoken)
+ continue; /* skip error token */
+ if ('\"' == *symbol)
{
- case SEMICOLON:
- return lex();
-
- case COMMA:
- break;
-
- case IDENTIFIER:
- if (symval->type_name == NULL)
- symval->type_name = name;
- else if (strcmp(name, symval->type_name) != 0)
- complain (_("type redeclaration for %s"), symval->tag);
+ /* use literal string only if given a symbol with an alias */
+ if (bp->alias)
+ symbol = bp->alias->tag;
+ else
+ continue;
+ }
- break;
+ /* Don't #define nonliteral tokens whose names contain periods. */
+ cp = symbol;
+ while ((c = *cp++) && c != '.');
+ if (c != '\0')
+ continue;
- default:
- return t;
- }
+ fprintf (file, "#define\t%s\t%d\n", symbol,
+ ((translations && !rawtoknumflag)
+ ? bp->user_token_number : bp->value));
+ if (semantic_parser)
+ fprintf (file, "#define\tT%s\t%d\n", symbol, bp->value);
}
+
+ putc ('\n', file);
}
-#endif
-/* Assign symbol numbers, and write definition of token names into
- fdefines. Set up vectors tags and sprec of names and precedences
- of symbols. */
+/*------------------------------------------------------------------.
+| Assign symbol numbers, and write definition of token names into |
+| fdefines. Set up vectors tags and sprec of names and precedences |
+| of symbols. |
+`------------------------------------------------------------------*/
static void
packsymbols (void)
{
- register bucket *bp;
- register int tokno = 1;
- register int i;
- register int last_user_token_number;
+ bucket *bp;
+ int tokno = 1;
+ int i;
+ int last_user_token_number;
static char DOLLAR[] = "$";
/* int lossage = 0; JF set but not used */
- tags = NEW2(nsyms + 1, char *);
+ tags = NEW2 (nsyms + 1, char *);
tags[0] = DOLLAR;
- user_toknums = NEW2(nsyms + 1, short);
+ user_toknums = NEW2 (nsyms + 1, short);
user_toknums[0] = 0;
- sprec = NEW2(nsyms, short);
- sassoc = NEW2(nsyms, short);
+ sprec = NEW2 (nsyms, short);
+ sassoc = NEW2 (nsyms, short);
max_user_token_number = 256;
last_user_token_number = 256;
@@ -1780,10 +1733,10 @@ packsymbols (void)
}
if (bp->user_token_number == SALIAS)
- continue; /* do not do processing below for SALIASs */
+ continue; /* do not do processing below for SALIASs */
- }
- else /* bp->class == STOKEN */
+ }
+ else /* bp->class == STOKEN */
{
bp->value = tokno++;
}
@@ -1805,35 +1758,34 @@ packsymbols (void)
if (translations)
{
- register int j;
+ int j;
- token_translations = NEW2(max_user_token_number+1, short);
+ token_translations = NEW2 (max_user_token_number + 1, short);
/* initialize all entries for literal tokens to 2, the internal
- token number for $undefined., which represents all invalid
- inputs. */
+ token number for $undefined., which represents all invalid
+ inputs. */
for (j = 0; j <= max_user_token_number; j++)
- token_translations[j] = 2;
+ token_translations[j] = 2;
for (bp = firstsymbol; bp; bp = bp->next)
- {
- if (bp->value >= ntokens)
- continue; /* non-terminal */
- if (bp->user_token_number == SALIAS)
+ {
+ if (bp->value >= ntokens)
+ continue; /* non-terminal */
+ if (bp->user_token_number == SALIAS)
continue;
- if (token_translations[bp->user_token_number] != 2)
+ if (token_translations[bp->user_token_number] != 2)
complain (_("tokens %s and %s both assigned number %d"),
tags[token_translations[bp->user_token_number]],
- bp->tag,
- bp->user_token_number);
- token_translations[bp->user_token_number] = bp->value;
- }
+ bp->tag, bp->user_token_number);
+ token_translations[bp->user_token_number] = bp->value;
+ }
}
error_token_number = errtoken->value;
- if (! noparserflag)
- output_token_defines(ftable);
+ if (!noparserflag)
+ output_token_defines (ftable);
if (startval->class == SUNKNOWN)
fatal (_("the start symbol %s is undefined"), startval->tag);
@@ -1844,14 +1796,15 @@ packsymbols (void)
if (definesflag)
{
- output_token_defines(fdefines);
+ output_token_defines (fdefines);
if (!pure_parser)
{
if (spec_name_prefix)
- fprintf(fdefines, "\nextern YYSTYPE %slval;\n", spec_name_prefix);
+ fprintf (fdefines, "\nextern YYSTYPE %slval;\n",
+ spec_name_prefix);
else
- fprintf(fdefines, "\nextern YYSTYPE yylval;\n");
+ fprintf (fdefines, "\nextern YYSTYPE yylval;\n");
}
if (semantic_parser)
@@ -1859,80 +1812,38 @@ packsymbols (void)
{
/* don't make these for dummy nonterminals made by gensym. */
if (*tags[i] != '@')
- fprintf(fdefines, "#define\tNT%s\t%d\n", tags[i], i);
+ fprintf (fdefines, "#define\tNT%s\t%d\n", tags[i], i);
}
#if 0
/* `fdefines' is now a temporary file, so we need to copy its
contents in `done', so we can't close it here. */
- fclose(fdefines);
+ fclose (fdefines);
fdefines = NULL;
#endif
}
}
-/* For named tokens, but not literal ones, define the name. The value
- is the user token number. */
-
-static void
-output_token_defines (FILE *file)
-{
- bucket *bp;
- register char *cp, *symbol;
- register char c;
-
- for (bp = firstsymbol; bp; bp = bp->next)
- {
- symbol = bp->tag; /* get symbol */
-
- if (bp->value >= ntokens) continue;
- if (bp->user_token_number == SALIAS) continue;
- if ('\'' == *symbol) continue; /* skip literal character */
- if (bp == errtoken) continue; /* skip error token */
- if ('\"' == *symbol)
- {
- /* use literal string only if given a symbol with an alias */
- if (bp->alias)
- symbol = bp->alias->tag;
- else
- continue;
- }
-
- /* Don't #define nonliteral tokens whose names contain periods. */
- cp = symbol;
- while ((c = *cp++) && c != '.');
- if (c != '\0') continue;
-
- fprintf (file, "#define\t%s\t%d\n", symbol,
- ((translations && ! rawtoknumflag)
- ? bp->user_token_number
- : bp->value));
- if (semantic_parser)
- fprintf (file, "#define\tT%s\t%d\n", symbol, bp->value);
- }
-
- putc('\n', file);
-}
-
-
-/* convert the rules into the representation using rrhs, rlhs and ritems. */
+/*---------------------------------------------------------------.
+| Convert the rules into the representation using RRHS, RLHS and |
+| RITEMS. |
+`---------------------------------------------------------------*/
static void
packgram (void)
{
- register int itemno;
- register int ruleno;
- register symbol_list *p;
-/* register bucket *bp; JF unused */
+ int itemno;
+ int ruleno;
+ symbol_list *p;
bucket *ruleprec;
- ritem = NEW2(nitems + 1, short);
- rlhs = NEW2(nrules, short) - 1;
- rrhs = NEW2(nrules, short) - 1;
- rprec = NEW2(nrules, short) - 1;
- rprecsym = NEW2(nrules, short) - 1;
- rassoc = NEW2(nrules, short) - 1;
+ ritem = NEW2 (nitems + 1, short);
+ rlhs = NEW2 (nrules, short) - 1;
+ rrhs = NEW2 (nrules, short) - 1;
+ rprec = NEW2 (nrules, short) - 1;
+ rprecsym = NEW2 (nrules, short) - 1;
+ rassoc = NEW2 (nrules, short) - 1;
itemno = 0;
ruleno = 1;
@@ -1950,28 +1861,127 @@ packgram (void)
ritem[itemno++] = p->sym->value;
/* A rule gets by default the precedence and associativity
of the last token in it. */
- if (p->sym->class == STOKEN)
+ if (p->sym->class == STOKEN)
{
rprec[ruleno] = p->sym->prec;
rassoc[ruleno] = p->sym->assoc;
}
- if (p) p = p->next;
+ if (p)
+ p = p->next;
}
/* If this rule has a %prec,
- the specified symbol's precedence replaces the default. */
+ the specified symbol's precedence replaces the default. */
if (ruleprec)
{
- rprec[ruleno] = ruleprec->prec;
- rassoc[ruleno] = ruleprec->assoc;
+ rprec[ruleno] = ruleprec->prec;
+ rassoc[ruleno] = ruleprec->assoc;
rprecsym[ruleno] = ruleprec->value;
}
ritem[itemno++] = -ruleno;
ruleno++;
- if (p) p = p->next;
+ if (p)
+ p = p->next;
}
ritem[itemno] = 0;
}
+
+/*-------------------------------------------------------------------.
+| Read in the grammar specification and record it in the format |
+| described in gram.h. All guards are copied into the FGUARD file |
+| and all actions into FACTION, in each case forming the body of a C |
+| function (YYGUARD or YYACTION) which contains a switch statement |
+| to decide which guard or action to execute. |
+`-------------------------------------------------------------------*/
+
+void
+reader (void)
+{
+ start_flag = 0;
+ startval = NULL; /* start symbol not specified yet. */
+
+#if 0
+ /* initially assume token number translation not needed. */
+ translations = 0;
+#endif
+ /* Nowadays translations is always set to 1, since we give `error' a
+ user-token-number to satisfy the Posix demand for YYERRCODE==256.
+ */
+ translations = 1;
+
+ nsyms = 1;
+ nvars = 0;
+ nrules = 0;
+ nitems = 0;
+ rline_allocated = 10;
+ rline = NEW2 (rline_allocated, short);
+
+ typed = 0;
+ lastprec = 0;
+
+ gensym_count = 0;
+
+ semantic_parser = 0;
+ pure_parser = 0;
+ yylsp_needed = 0;
+
+ grammar = NULL;
+
+ init_lex ();
+ lineno = 1;
+
+ /* Initialize the symbol table. */
+ tabinit ();
+ /* Construct the error token */
+ errtoken = getsym ("error");
+ errtoken->class = STOKEN;
+ errtoken->user_token_number = 256; /* Value specified by POSIX. */
+ /* Construct a token that represents all undefined literal tokens.
+ It is always token number 2. */
+ undeftoken = getsym ("$undefined.");
+ undeftoken->class = STOKEN;
+ undeftoken->user_token_number = 2;
+
+ /* Read the declaration section. Copy %{ ... %} groups to FTABLE
+ and FDEFINES file. Also notice any %token, %left, etc. found
+ there. */
+ putc ('\n', ftable);
+ fprintf (ftable, "\
+/* %s, made from %s\n\
+ by GNU bison %s. */\n\
+\n", noparserflag ? "Bison-generated parse tables" : "A Bison parser", infile, VERSION);
+
+ fputs ("#define YYBISON 1 /* Identify Bison output. */\n\n", ftable);
+ read_declarations ();
+ /* Start writing the guard and action files, if they are needed. */
+ output_headers ();
+ /* Read in the grammar, build grammar in list form. Write out
+ guards and actions. */
+ readgram ();
+ /* Now we know whether we need the line-number stack. If we do,
+ write its type into the .tab.h file. */
+ if (fdefines)
+ reader_output_yylsp (fdefines);
+ /* Write closing delimiters for actions and guards. */
+ output_trailers ();
+ if (yylsp_needed)
+ fputs ("#define YYLSP_NEEDED\n\n", ftable);
+ /* Assign the symbols their symbol numbers. Write #defines for the
+ token symbols into FDEFINES if requested. */
+ packsymbols ();
+ /* Convert the grammar into the format described in gram.h. */
+ packgram ();
+ /* Free the symbol table data structure since symbols are now all
+ referred to by symbol number. */
+ free_symtab ();
+}
+
+void
+reader_output_yylsp (FILE *f)
+{
+ if (yylsp_needed)
+ fprintf (f, LTYPESTR);
+}
diff --git a/src/reader.h b/src/reader.h
new file mode 100644
index 00000000..cf97a456
--- /dev/null
+++ b/src/reader.h
@@ -0,0 +1,39 @@
+/* Input parser for bison
+ Copyright (C) 2000 Free Software Foundation, Inc.
+
+ This file is part of Bison, the GNU Compiler Compiler.
+
+ Bison is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ Bison is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Bison; see the file COPYING. If not, write to
+ the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#ifndef READER_H_
+# define READER_H_
+
+/* Read in the grammar specification and record it in the format
+ described in gram.h. All guards are copied into the FGUARD file
+ and all actions into FACTION, in each case forming the body of a C
+ function (YYGUARD or YYACTION) which contains a switch statement to
+ decide which guard or action to execute. */
+
+extern void reader PARAMS ((void));
+
+
+extern void reader_output_yylsp PARAMS ((FILE *));
+
+extern int lineno;
+extern char **tags;
+extern short *user_toknums;
+
+#endif /* !READER_H_ */
diff --git a/src/state.h b/src/state.h
index 67b78cfc..43e6809b 100644
--- a/src/state.h
+++ b/src/state.h
@@ -1,138 +1,138 @@
/* Type definitions for nondeterministic finite state machine for bison,
- Copyright (C) 1984, 1989 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1989, 2000 Free Software Foundation, Inc.
-This file is part of Bison, the GNU Compiler Compiler.
+ This file is part of Bison, the GNU Compiler Compiler.
-Bison is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+ Bison is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
-Bison is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+ Bison is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
-You should have received a copy of the GNU General Public License
-along with Bison; see the file COPYING. If not, write to
-the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+ You should have received a copy of the GNU General Public License
+ along with Bison; see the file COPYING. If not, write to
+ the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
/* These type definitions are used to represent a nondeterministic
- finite state machine that parses the specified grammar.
- This information is generated by the function generate_states
- in the file LR0.
-
-Each state of the machine is described by a set of items --
-particular positions in particular rules -- that are the possible
-places where parsing could continue when the machine is in this state.
-These symbols at these items are the allowable inputs that can follow now.
-
-A core represents one state. States are numbered in the number field.
-When generate_states is finished, the starting state is state 0
-and nstates is the number of states. (A transition to a state
-whose state number is nstates indicates termination.) All the cores
-are chained together and first_state points to the first one (state 0).
-
-For each state there is a particular symbol which must have been the
-last thing accepted to reach that state. It is the accessing_symbol
-of the core.
-
-Each core contains a vector of nitems items which are the indices
-in the ritems vector of the items that are selected in this state.
-
-The link field is used for chaining buckets that hash states by
-their itemsets. This is for recognizing equivalent states and
-combining them when the states are generated.
-
-The two types of transitions are shifts (push the lookahead token
-and read another) and reductions (combine the last n things on the
-stack via a rule, replace them with the symbol that the rule derives,
-and leave the lookahead token alone). When the states are generated,
-these transitions are represented in two other lists.
-
-Each shifts structure describes the possible shift transitions out
-of one state, the state whose number is in the number field.
-The shifts structures are linked through next and first_shift points to them.
-Each contains a vector of numbers of the states that shift transitions
-can go to. The accessing_symbol fields of those states' cores say what kind
-of input leads to them.
-
-A shift to state zero should be ignored. Conflict resolution
-deletes shifts by changing them to zero.
-
-Each reductions structure describes the possible reductions at the state
-whose number is in the number field. The data is a list of nreds rules,
-represented by their rule numbers. first_reduction points to the list
-of these structures.
-
-Conflict resolution can decide that certain tokens in certain
-states should explicitly be errors (for implementing %nonassoc).
-For each state, the tokens that are errors for this reason
-are recorded in an errs structure, which has the state number
-in its number field. The rest of the errs structure is full
-of token numbers.
-
-There is at least one shift transition present in state zero.
-It leads to a next-to-final state whose accessing_symbol is
-the grammar's start symbol. The next-to-final state has one shift
-to the final state, whose accessing_symbol is zero (end of input).
-The final state has one shift, which goes to the termination state
-(whose number is nstates-1).
-The reason for the extra state at the end is to placate the parser's
-strategy of making all decisions one token ahead of its actions. */
-
-
-typedef
- struct core
- {
- struct core *next;
- struct core *link;
- short number;
- short accessing_symbol;
- short nitems;
- short items[1];
- }
- core;
-
-
-
-typedef
- struct shifts
- {
- struct shifts *next;
- short number;
- short nshifts;
- short shifts[1];
- }
- shifts;
-
-
-
-typedef
- struct errs
- {
- short nerrs;
- short errs[1];
- }
- errs;
-
-
-
-typedef
- struct reductions
- {
- struct reductions *next;
- short number;
- short nreds;
- short rules[1];
- }
- reductions;
-
-
+ finite state machine that parses the specified grammar. This
+ information is generated by the function generate_states in the
+ file LR0.
+
+ Each state of the machine is described by a set of items --
+ particular positions in particular rules -- that are the possible
+ places where parsing could continue when the machine is in this
+ state. These symbols at these items are the allowable inputs that
+ can follow now.
+
+ A core represents one state. States are numbered in the number
+ field. When generate_states is finished, the starting state is
+ state 0 and nstates is the number of states. (A transition to a
+ state whose state number is nstates indicates termination.) All
+ the cores are chained together and first_state points to the first
+ one (state 0).
+
+ For each state there is a particular symbol which must have been
+ the last thing accepted to reach that state. It is the
+ accessing_symbol of the core.
+
+ Each core contains a vector of nitems items which are the indices
+ in the ritems vector of the items that are selected in this state.
+
+ The link field is used for chaining buckets that hash states by
+ their itemsets. This is for recognizing equivalent states and
+ combining them when the states are generated.
+
+ The two types of transitions are shifts (push the lookahead token
+ and read another) and reductions (combine the last n things on the
+ stack via a rule, replace them with the symbol that the rule
+ derives, and leave the lookahead token alone). When the states are
+ generated, these transitions are represented in two other lists.
+
+ Each shifts structure describes the possible shift transitions out
+ of one state, the state whose number is in the number field. The
+ shifts structures are linked through next and first_shift points to
+ them. Each contains a vector of numbers of the states that shift
+ transitions can go to. The accessing_symbol fields of those
+ states' cores say what kind of input leads to them.
+
+ A shift to state zero should be ignored. Conflict resolution
+ deletes shifts by changing them to zero.
+
+ Each reductions structure describes the possible reductions at the
+ state whose number is in the number field. The data is a list of
+ nreds rules, represented by their rule numbers. first_reduction
+ points to the list of these structures.
+
+ Conflict resolution can decide that certain tokens in certain
+ states should explicitly be errors (for implementing %nonassoc).
+ For each state, the tokens that are errors for this reason are
+ recorded in an errs structure, which has the state number in its
+ number field. The rest of the errs structure is full of token
+ numbers.
+
+ There is at least one shift transition present in state zero. It
+ leads to a next-to-final state whose accessing_symbol is the
+ grammar's start symbol. The next-to-final state has one shift to
+ the final state, whose accessing_symbol is zero (end of input).
+ The final state has one shift, which goes to the termination state
+ (whose number is nstates-1). The reason for the extra state at the
+ end is to placate the parser's strategy of making all decisions one
+ token ahead of its actions. */
+
+#ifndef STATE_H_
+# define STATE_H_
+
+typedef struct core
+{
+ struct core *next;
+ struct core *link;
+ short number;
+ short accessing_symbol;
+ short nitems;
+ short items[1];
+}
+core;
+
+
+
+typedef struct shifts
+{
+ struct shifts *next;
+ short number;
+ short nshifts;
+ short shifts[1];
+}
+shifts;
+
+
+
+typedef struct errs
+{
+ short nerrs;
+ short errs[1];
+}
+errs;
+
+
+
+typedef struct reductions
+{
+ struct reductions *next;
+ short number;
+ short nreds;
+ short rules[1];
+}
+reductions;
extern int nstates;
extern core *first_state;
extern shifts *first_shift;
extern reductions *first_reduction;
+
+#endif /* !STATE_H_ */
--
2.47.2