-/* Input parser for bison
- Copyright (C) 1984, 86, 89, 92, 98, 2000 Free Software Foundation, Inc.
+/* Input parser for Bison
+
+ Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000-2003, 2005-2007,
+ 2009-2012 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
+ This program 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.
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
- Bison is distributed in the hope that it will be useful,
+ This program 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. */
-
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
-/* 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.
+#include <config.h>
+#include "system.h"
- The entry point is reader (). */
+#include <quote.h>
-#include "system.h"
-#include "getargs.h"
+#include "complain.h"
+#include "conflicts.h"
#include "files.h"
-#include "alloc.h"
-#include "symtab.h"
-#include "lex.h"
+#include "getargs.h"
#include "gram.h"
-#include "complain.h"
-#include "output.h"
-
-#define LTYPESTR "\
-\n\
-#ifndef YYLTYPE\n\
-typedef\n\
- struct yyltype\n\
-\
- {\n\
- int timestamp;\n\
- int first_line;\n\
- int first_column;\
-\n\
- int last_line;\n\
- int last_column;\n\
- char *text;\n\
- }\n\
-\
- yyltype;\n\
-\n\
-#define YYLTYPE yyltype\n\
-#endif\n\
-\n"
-
-/* Number of slots allocated (but not necessarily used yet) in `rline' */
-static int rline_allocated;
-
-extern bucket *symval;
-extern int numval;
-extern int expected_conflicts;
-extern char *token_buffer;
-extern int maxtoken;
-
-extern void init_lex PARAMS((void));
-extern char *grow_token_buffer PARAMS((char *));
-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 unlex PARAMS((int));
-
-extern int skip_white_space PARAMS((void));
-extern int parse_percent_token PARAMS((void));
-extern int lex PARAMS((void));
-
-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));
-
-#if 0
-static int get_type PARAMS((void));
-#endif
-
-int lineno;
-char **tags;
-int *user_toknums;
-static symbol_list *grammar;
-static int start_flag;
-static bucket *startval;
-
-/* Nonzero if components of semantic values are used, implying
- they must be unions. */
-static int value_components_used;
-
-static int typed; /* nonzero if %union has been seen. */
-
-static int lastprec; /* incremented for each %left, %right or %nonassoc seen */
-
-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;
-
-\f
-/*===================\
-| Low level lexing. |
-\===================*/
-
-static void
-skip_to_char (int target)
-{
- int c;
- if (target == '\n')
- complain (_(" Skipping to next \\n"));
- else
- complain (_(" Skipping to next %c"), target);
-
- do
- c = skip_white_space ();
- while (c != target && c != EOF);
- if (c != EOF)
- ungetc (c, finput);
-}
-
+#include "muscle-tab.h"
+#include "reader.h"
+#include "symlist.h"
+#include "symtab.h"
+#include "scan-gram.h"
+#include "scan-code.h"
-/*---------------------------------------------------------.
-| Read a signed integer from STREAM and return its value. |
-`---------------------------------------------------------*/
+static void prepare_percent_define_front_end_variables (void);
+static void check_and_convert_grammar (void);
-static inline int
-read_signed_integer (FILE *stream)
-{
- register int c = getc (stream);
- register int sign = 1;
- register int n = 0;
-
- if (c == '-')
- {
- c = getc (stream);
- sign = -1;
- }
+static symbol_list *grammar = NULL;
+static bool start_flag = false;
+merger_list *merge_functions;
- while (isdigit (c))
- {
- n = 10 * n + (c - '0');
- c = getc (stream);
- }
+/* Was %union seen? */
+bool union_seen = false;
- ungetc (c, stream);
+/* Was a tag seen? */
+bool tag_seen = false;
- return sign * n;
-}
+/* Should rules have a default precedence? */
+bool default_prec = true;
\f
-/*-------------------------------------------------------------------.
-| Dump the string from FINPUT to FOUTPUT. MATCH is the delimiter of |
-| the string (either ' or "). |
-`-------------------------------------------------------------------*/
+/*-----------------------.
+| Set the start symbol. |
+`-----------------------*/
-static inline void
-copy_string (FILE *fin, FILE *fout, int match)
+void
+grammar_start_symbol_set (symbol *sym, location loc)
{
- int c;
-
- putc (match, fout);
- c = getc (fin);
-
- while (c != match)
+ if (start_flag)
+ complain_at (loc, complaint, _("multiple %s declarations"), "%start");
+ else
{
- if (c == EOF)
- fatal (_("unterminated string at end of file"));
- if (c == '\n')
- {
- complain (_("unterminated string"));
- ungetc (c, fin);
- c = match; /* invent terminator */
- continue;
- }
-
- putc(c, fout);
-
- if (c == '\\')
- {
- c = getc (fin);
- if (c == EOF)
- fatal (_("unterminated string at end of file"));
- putc (c, fout);
- if (c == '\n')
- lineno++;
- }
-
- c = getc(fin);
+ start_flag = true;
+ startsymbol = sym;
+ startsymbol_location = loc;
}
-
- putc(c, fout);
}
+\f
-/*---------------------------------------------------------------.
-| Dump the comment from IN to OUT1 and OUT2. C is either `*' or |
-| `/', depending upon the type of comments used. OUT2 might be |
-| NULL. |
-`---------------------------------------------------------------*/
+/*------------------------------------------------------------------------.
+| Return the merger index for a merging function named NAME. Records the |
+| function, if new, in MERGER_LIST. |
+`------------------------------------------------------------------------*/
-static inline void
-copy_comment2 (FILE *in, FILE *out1, FILE* out2, int c)
+static int
+get_merge_function (uniqstr name)
{
- int cplus_comment;
- register int ended;
-
- cplus_comment = (c == '/');
- putc (c, out1);
- if (out2)
- putc (c, out2);
- c = getc (in);
-
- ended = 0;
- while (!ended)
- {
- if (!cplus_comment && c == '*')
- {
- while (c == '*')
- {
- putc (c, out1);
- if (out2)
- putc (c, out2);
- c = getc (in);
- }
-
- if (c == '/')
- {
- putc(c, out1);
- if (out2)
- putc(c, out2);
- ended = 1;
- }
- }
- else if (c == '\n')
- {
- lineno++;
- putc (c, out1);
- if (out2)
- putc (c, out2);
- if (cplus_comment)
- ended = 1;
- else
- c = getc (in);
- }
- else if (c == EOF)
- fatal (_("unterminated comment"));
- else
- {
- putc (c, out1);
- if (out2)
- putc (c, out2);
- c = getc (in);
- }
- }
+ merger_list *syms;
+ merger_list head;
+ int n;
+
+ if (! glr_parser)
+ return 0;
+
+ head.next = merge_functions;
+ for (syms = &head, n = 1; syms->next; syms = syms->next, n += 1)
+ if (UNIQSTR_EQ (name, syms->next->name))
+ break;
+ if (syms->next == NULL)
+ {
+ syms->next = xmalloc (sizeof syms->next[0]);
+ syms->next->name = uniqstr_new (name);
+ /* After all symbol type declarations have been parsed, packgram invokes
+ record_merge_function_type to set the type. */
+ syms->next->type = NULL;
+ syms->next->next = NULL;
+ merge_functions = head.next;
+ }
+ return n;
}
+/*-------------------------------------------------------------------------.
+| For the existing merging function with index MERGER, record the result |
+| type as TYPE as required by the lhs of the rule whose %merge declaration |
+| is at DECLARATION_LOC. |
+`-------------------------------------------------------------------------*/
-/* Dump the comment from FIN to FOUT. C is either `*' or `/',
- depending upon the type of comments used. */
-
-static inline void
-copy_comment (FILE *fin, FILE *fout, int c)
+static void
+record_merge_function_type (int merger, uniqstr type, location declaration_loc)
{
- copy_comment2 (fin, fout, NULL, c);
+ int merger_find;
+ merger_list *merge_function;
+
+ if (merger <= 0)
+ return;
+
+ if (type == NULL)
+ type = uniqstr_new ("");
+
+ merger_find = 1;
+ for (merge_function = merge_functions;
+ merge_function != NULL && merger_find != merger;
+ merge_function = merge_function->next)
+ merger_find += 1;
+ aver (merge_function != NULL && merger_find == merger);
+ if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
+ {
+ unsigned indent = 0;
+ complain_at_indent (declaration_loc, complaint, &indent,
+ _("result type clash on merge function %s: "
+ "<%s> != <%s>"),
+ quote (merge_function->name), type,
+ merge_function->type);
+ indent += SUB_INDENT;
+ complain_at_indent (merge_function->type_declaration_location, complaint,
+ &indent,
+ _("previous declaration"));
+ }
+ merge_function->type = uniqstr_new (type);
+ merge_function->type_declaration_location = declaration_loc;
}
+/*--------------------------------------.
+| Free all merge-function definitions. |
+`--------------------------------------*/
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)
+free_merger_functions (void)
{
- 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. */
-
-static void
-read_declarations (void)
-{
- register int c;
- register int tok;
-
- for (;;)
+ merger_list *L0 = merge_functions;
+ while (L0)
{
- 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;
-
- case NOOP:
- break;
-
- 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('%');
- }
+ merger_list *L1 = L0->next;
+ free (L0);
+ L0 = L1;
}
}
+\f
+/*-------------------------------------------------------------------.
+| 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 actions are copied out, labelled by the rule number they apply |
+| to. |
+`-------------------------------------------------------------------*/
-/* Copy the contents of a `%{ ... %}' into the definitions file. The
- `%{' has already been read. Return after reading the `%}'. */
+/* The (currently) last symbol of GRAMMAR. */
+static symbol_list *grammar_end = NULL;
-static void
-copy_definition (void)
+/* Append SYM to the grammar. */
+static symbol_list *
+grammar_symbol_append (symbol *sym, location loc)
{
- register int c;
- /* -1 while reading a character if prev char was %. */
- register int after_percent;
-
- if (!nolinesflag)
- fprintf(fattrs, "#line %d \"%s\"\n", lineno, infile);
-
- after_percent = 0;
+ symbol_list *p = symbol_list_sym_new (sym, loc);
- c = getc (finput);
+ if (grammar_end)
+ grammar_end->next = p;
+ else
+ grammar = p;
- for (;;)
- {
- switch (c)
- {
- case '\n':
- putc(c, fattrs);
- lineno++;
- break;
-
- case '%':
- after_percent = -1;
- break;
-
- case '\'':
- case '"':
- copy_string (finput, fattrs, c);
- break;
-
- case '/':
- putc (c, fattrs);
- c = getc (finput);
- if (c != '*' && c != '/')
- continue;
- copy_comment (finput, fattrs, c);
- break;
-
- case EOF:
- fatal ("%s",
- _("unterminated `%{' definition"));
-
- default:
- putc(c, fattrs);
- }
-
- c = getc(finput);
-
- if (after_percent)
- {
- if (c == '}')
- return;
- putc('%', fattrs);
- }
- after_percent = 0;
+ grammar_end = p;
- }
+ /* A null SYM stands for an end of rule; it is not an actual
+ part of it. */
+ if (sym)
+ ++nritems;
+ return p;
}
-
-
-/* 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)
+assign_named_ref (symbol_list *p, named_ref *name)
{
- register int token = 0;
- register char *typename = 0;
- register struct bucket *symbol = NULL; /* pts to symbol being defined */
- int k;
+ symbol *sym = p->content.sym;
- for (;;)
+ if (name->id == sym->tag)
{
- int tmp_char = ungetc (skip_white_space (), finput);
-
- if (tmp_char == '%')
- return;
- if (tmp_char == EOF)
- fatal (_("Premature EOF after %s"), token_buffer);
-
- token = lex();
- if (token == COMMA)
- {
- symbol = NULL;
- continue;
- }
- if (token == TYPENAME)
- {
- 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)
- {
- translations = 1;
- symval->class = STOKEN;
- symval->type_name = typename;
- symval->user_token_number = symbol->user_token_number;
- symbol->user_token_number = SALIAS;
-
- symval->alias = symbol;
- symbol->alias = symval;
- symbol = NULL;
-
- nsyms--; /* symbol and symval combined are only one symbol */
- }
- else if (token == IDENTIFIER)
- {
- int oldclass = symval->class;
- symbol = symval;
-
- if (symbol->class == what_is_not)
- complain (_("symbol %s redefined"), symbol->tag);
- symbol->class = what_is;
- if (what_is == SNTERM && oldclass != SNTERM)
- symbol->value = nvars++;
-
- if (typename)
- {
- if (symbol->type_name == NULL)
- symbol->type_name = typename;
- 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('%');
- }
+ complain_at (name->loc, Wother,
+ _("duplicated symbol name for %s ignored"),
+ quote (sym->tag));
+ named_ref_free (name);
}
-
+ else
+ p->named_ref = name;
}
-/* 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
-*/
+/* The rule currently being defined, and the previous rule.
+ CURRENT_RULE points to the first LHS of the current rule, while
+ PREVIOUS_RULE_END points to the *end* of the previous rule (NULL). */
+static symbol_list *current_rule = NULL;
+static symbol_list *previous_rule_end = NULL;
-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 */
+/*----------------------------------------------.
+| Create a new rule for LHS in to the GRAMMAR. |
+`----------------------------------------------*/
- 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;
+void
+grammar_current_rule_begin (symbol *lhs, location loc,
+ named_ref *lhs_name)
+{
+ symbol_list* p;
- token = lex(); /* get number or literal string */
+ /* Start a new rule and record its lhs. */
+ ++nrules;
+ previous_rule_end = grammar_end;
- if (token == NUMBER) {
- usrtoknum = numval;
- token = lex(); /* okay, did number, now get literal */
- }
- else usrtoknum = 0;
+ p = grammar_symbol_append (lhs, loc);
+ if (lhs_name)
+ assign_named_ref (p, named_ref_copy (lhs_name));
- /* process literal string token */
+ current_rule = grammar_end;
- if (token != IDENTIFIER || *symval->tag != '\"')
+ /* Mark the rule's lhs as a nonterminal if not already so. */
+ if (lhs->class == unknown_sym)
{
- complain (_("expected string constant instead of %s"),
- token_buffer);
- skip_to_char('%');
- return;
+ lhs->class = nterm_sym;
+ lhs->number = nvars;
+ ++nvars;
}
- 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 */
+ else if (lhs->class == token_sym)
+ complain_at (loc, complaint, _("rule given for %s, which is a token"),
+ lhs->tag);
}
-/* Parse what comes after %start */
+/*----------------------------------------------------------------------.
+| A symbol should be used if either: |
+| 1. It has a destructor. |
+| 2. The symbol is a mid-rule symbol (i.e., the generated LHS |
+| replacing a mid-rule action) that was assigned to or used, as in |
+| "exp: { $$ = 1; } { $$ = $1; }". |
+`----------------------------------------------------------------------*/
-static void
-parse_start_decl (void)
+static bool
+symbol_should_be_used (symbol_list const *s, bool *midrule_warning)
{
- if (start_flag)
- complain (_("multiple %s declarations"), "%start");
- if (lex () != IDENTIFIER)
- complain (_("invalid %s declaration"), "%start");
- else
- {
- start_flag = 1;
- startval = symval;
- }
+ if (symbol_code_props_get (s->content.sym, destructor)->code)
+ return true;
+ if ((s->midrule && s->midrule->action_props.is_value_used)
+ || (s->midrule_parent_rule
+ && symbol_list_n_get (s->midrule_parent_rule,
+ s->midrule_parent_rhs_index)
+ ->action_props.is_value_used))
+ {
+ *midrule_warning = true;
+ return true;
+ }
+ return false;
}
-
-
-/* read in a %type declaration and record its information for get_type_name to access */
+/*----------------------------------------------------------------.
+| Check that the rule R is properly defined. For instance, there |
+| should be no type clash on the default action. |
+`----------------------------------------------------------------*/
static void
-parse_type_decl (void)
+grammar_rule_check (const symbol_list *r)
{
- register int k;
- register char *name;
+ /* Type check.
- if (lex() != TYPENAME)
- {
- complain ("%s", _("%type declaration has no <typename>"));
- skip_to_char('%');
- return;
- }
+ If there is an action, then there is nothing we can do: the user
+ is allowed to shoot herself in the foot.
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
-
- for (;;)
+ Don't worry about the default action if $$ is untyped, since $$'s
+ value can't be used. */
+ if (!r->action_props.code && r->content.sym->type_name)
{
- 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)
- {
-
- case COMMA:
- case SEMICOLON:
- 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);
+ symbol *first_rhs = r->next->content.sym;
+ /* If $$ is being set in default way, report if any type mismatch. */
+ if (first_rhs)
+ {
+ char const *lhs_type = r->content.sym->type_name;
+ const char *rhs_type =
+ first_rhs->type_name ? first_rhs->type_name : "";
+ if (!UNIQSTR_EQ (lhs_type, rhs_type))
+ complain_at (r->location, Wother,
+ _("type clash on default action: <%s> != <%s>"),
+ lhs_type, rhs_type);
+ }
+ /* Warn if there is no default for $$ but we need one. */
+ else
+ complain_at (r->location, Wother,
+ _("empty rule for typed nonterminal, and no action"));
+ }
- break;
+ /* Check that symbol values that should be used are in fact used. */
+ {
+ symbol_list const *l = r;
+ int n = 0;
+ for (; l && l->content.sym; l = l->next, ++n)
+ {
+ bool midrule_warning = false;
+ if (!l->action_props.is_value_used
+ && symbol_should_be_used (l, &midrule_warning)
+ /* The default action, $$ = $1, `uses' both. */
+ && (r->action_props.code || (n != 0 && n != 1)))
+ {
+ warnings warn_flag = midrule_warning ? Wmidrule_values : Wother;
+ if (n)
+ complain_at (r->location, warn_flag, _("unused value: $%d"), n);
+ else
+ complain_at (r->location, warn_flag, _("unset value: $$"));
+ }
+ }
+ }
- default:
- complain (_("invalid %%type declaration due to item: %s"),
- token_buffer);
- skip_to_char('%');
- }
- }
+ /* See comments in grammar_current_rule_prec_set for how POSIX
+ mandates this complaint. It's only for identifiers, so skip
+ it for char literals and strings, which are always tokens. */
+ if (r->ruleprec
+ && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
+ && r->ruleprec->status != declared && !r->ruleprec->prec)
+ complain_at (r->location, Wother,
+ _("token for %%prec is not defined: %s"), r->ruleprec->tag);
}
+/*-------------------------------------.
+| End the currently being grown rule. |
+`-------------------------------------*/
-/* read in a %left, %right or %nonassoc declaration and record its information. */
-/* assoc is either LEFT_ASSOC, RIGHT_ASSOC or NON_ASSOC. */
-
-static void
-parse_assoc_decl (int assoc)
+void
+grammar_current_rule_end (location loc)
{
- register int k;
- register char *name = NULL;
- register int prev = 0;
-
- lastprec++; /* Assign a new precedence level, never 0. */
-
- for (;;)
- {
- 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)
- {
-
- case TYPENAME:
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
- break;
-
- case COMMA:
- break;
-
- case IDENTIFIER:
- if (symval->prec != 0)
- complain (_("redefining precedence of %s"), symval->tag);
- symval->prec = lastprec;
- symval->assoc = assoc;
- if (symval->class == SNTERM)
- complain (_("symbol %s redefined"), symval->tag);
- symval->class = STOKEN;
- if (name)
- { /* record the type, if one is specified */
- 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;
-
- 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('%');
- }
- break;
-
- case SEMICOLON:
- return;
-
- default:
- complain (_("unexpected item: %s"), token_buffer);
- skip_to_char('%');
- }
-
- prev = t;
-
- }
+ /* Put an empty link in the list to mark the end of this rule */
+ grammar_symbol_append (NULL, grammar_end->location);
+ current_rule->location = loc;
}
+/*-------------------------------------------------------------------.
+| The previous action turns out the be a mid-rule action. Attach it |
+| to the current rule, i.e., create a dummy symbol, attach it this |
+| mid-rule action, and append this dummy nonterminal to the current |
+| rule. |
+`-------------------------------------------------------------------*/
-/* copy the union declaration into fattrs (and fdefines),
- where it is made into the
- definition of YYSTYPE, the type of elements of the parser value stack. */
-
-static void
-parse_union_decl (void)
+void
+grammar_midrule_action (void)
{
- register int c;
- register int count = 0;
-
- if (typed)
- complain (_("multiple %s declarations"), "%union");
-
- typed = 1;
-
- if (!nolinesflag)
- fprintf (fattrs, "\n#line %d \"%s\"\n", lineno, infile);
+ /* 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, whose location is that of the midrule
+ action. Create the MIDRULE. */
+ location dummy_location = current_rule->action_props.location;
+ symbol *dummy = dummy_symbol_get (dummy_location);
+ symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
+
+ /* Remember named_ref of previous action. */
+ named_ref *action_name = current_rule->action_props.named_ref;
+
+ /* Make a new rule, whose body is empty, before the current one, so
+ that the action just read can belong to it. */
+ ++nrules;
+ ++nritems;
+ /* Attach its location and actions to that of the DUMMY. */
+ midrule->location = dummy_location;
+ code_props_rule_action_init (&midrule->action_props,
+ current_rule->action_props.code,
+ current_rule->action_props.location,
+ midrule, 0,
+ current_rule->action_props.is_predicate);
+ code_props_none_init (¤t_rule->action_props);
+
+ if (previous_rule_end)
+ previous_rule_end->next = midrule;
else
- fprintf (fattrs, "\n");
+ grammar = midrule;
- fprintf (fattrs, "typedef union");
- if (fdefines)
- fprintf (fdefines, "typedef union");
+ /* End the dummy's rule. */
+ midrule->next = symbol_list_sym_new (NULL, dummy_location);
+ midrule->next->next = current_rule;
- c = getc (finput);
+ previous_rule_end = midrule->next;
- while (c != EOF)
- {
- putc (c, fattrs);
- if (fdefines)
- putc (c, fdefines);
-
- switch (c)
- {
- case '\n':
- lineno++;
- break;
-
- case '/':
- c = getc (finput);
- if (c != '*' && c != '/')
- continue;
- copy_comment2 (finput, fattrs, fdefines, c);
- break;
-
-
- case '{':
- count++;
- break;
-
- case '}':
- if (count == 0)
- complain (_("unmatched %s"), "`}'");
- count--;
- if (count <= 0)
- {
- fprintf (fattrs, " YYSTYPE;\n");
- if (fdefines)
- fprintf (fdefines, " YYSTYPE;\n");
- /* JF don't choke on trailing semi */
- c = skip_white_space ();
- if (c != ';')
- ungetc (c,finput);
- return;
- }
- }
-
- c = getc (finput);
- }
+ /* Insert the dummy nonterminal replacing the midrule action into
+ the current rule. Bind it to its dedicated rule. */
+ grammar_current_rule_symbol_append (dummy, dummy_location,
+ action_name);
+ grammar_end->midrule = midrule;
+ midrule->midrule_parent_rule = current_rule;
+ midrule->midrule_parent_rhs_index = symbol_list_length (current_rule->next);
}
-/* parse the declaration %expect N which says to expect N
- shift-reduce conflicts. */
+/* Set the precedence symbol of the current rule to PRECSYM. */
-static void
-parse_expect_decl (void)
+void
+grammar_current_rule_prec_set (symbol *precsym, location loc)
{
- register int c;
- register int count;
- char buffer[20];
-
- c = getc(finput);
- while (c == ' ' || c == '\t')
- c = getc(finput);
-
- count = 0;
- while (c >= '0' && c <= '9')
- {
- if (count < 20)
- buffer[count++] = c;
- c = getc(finput);
- }
- buffer[count] = 0;
-
- ungetc (c, finput);
-
- if (count <= 0 || count > 10)
- complain ("%s", _("argument of %expect is not an integer"));
- expected_conflicts = atoi (buffer);
+ /* POSIX says that any identifier is a nonterminal if it does not
+ appear on the LHS of a grammar rule and is not defined by %token
+ or by one of the directives that assigns precedence to a token. We
+ ignore this here because the only kind of identifier that POSIX
+ allows to follow a %prec is a token and because assuming it's a
+ token now can produce more logical error messages. Nevertheless,
+ grammar_rule_check does obey what we believe is the real intent of
+ POSIX here: that an error be reported for any identifier that
+ appears after %prec but that is not defined separately as a
+ token. */
+ symbol_class_set (precsym, token_sym, loc, false);
+ if (current_rule->ruleprec)
+ complain_at (loc, complaint, _("only one %s allowed per rule"), "%prec");
+ current_rule->ruleprec = precsym;
}
-/* that's all of parsing the declaration section */
-\f
-/* 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 `$0' with
- respect to the top of the stack. */
-static inline void
-copy_at (FILE *fin, FILE *fout, int stack_offset)
-{
- int c;
-
- c = getc (fin);
- if (c == '$')
- {
- fprintf (fout, "yyloc");
- yylsp_needed = 1;
- }
- else if (isdigit(c) || c == '-')
- {
- int n;
-
- ungetc (c, fin);
- n = read_signed_integer (fin);
+/* Attach dynamic precedence DPREC to the current rule. */
- fprintf (fout, "yylsp[%d]", n - stack_offset);
- yylsp_needed = 1;
- }
- else
- complain (_("@%s is invalid"), printable_version (c));
+void
+grammar_current_rule_dprec_set (int dprec, location loc)
+{
+ if (! glr_parser)
+ complain_at (loc, Wother, _("%s affects only GLR parsers"),
+ "%dprec");
+ if (dprec <= 0)
+ complain_at (loc, complaint, _("%s must be followed by positive number"),
+ "%dprec");
+ else if (current_rule->dprec != 0)
+ complain_at (loc, complaint, _("only one %s allowed per rule"), "%dprec");
+ current_rule->dprec = dprec;
}
+/* Attach a merge function NAME with argument type TYPE to current
+ rule. */
-/* Get the data type (alternative in the union) of the value for
- symbol n in rule rule. */
-
-static char *
-get_type_name (int n, symbol_list *rule)
+void
+grammar_current_rule_merge_set (uniqstr name, location loc)
{
- register int i;
- register symbol_list *rp;
-
- if (n < 0)
- {
- complain (_("invalid $ value"));
- return NULL;
- }
-
- rp = rule;
- i = 0;
-
- while (i < n)
- {
- rp = rp->next;
- if (rp == NULL || rp->sym == NULL)
- {
- complain (_("invalid $ value"));
- return NULL;
- }
- i++;
- }
-
- return rp->sym->type_name;
+ if (! glr_parser)
+ complain_at (loc, Wother, _("%s affects only GLR parsers"),
+ "%merge");
+ if (current_rule->merger != 0)
+ complain_at (loc, complaint, _("only one %s allowed per rule"), "%merge");
+ current_rule->merger = get_merge_function (name);
+ current_rule->merger_declaration_location = loc;
}
+/* Attach SYM to the current rule. If needed, move the previous
+ action as a mid-rule action. */
-
-/* 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 `$0' with
- respect to the top of the stack, for the simple parser in which the
- stack is not popped until after the guard is run. */
-
-static void
-copy_guard (symbol_list *rule, int stack_offset)
+void
+grammar_current_rule_symbol_append (symbol *sym, location loc,
+ named_ref *name)
{
- register int c;
- register int n;
- register int count;
- register char *type_name;
- int brace_flag = 0;
-
- /* offset is always 0 if parser has already popped the stack pointer */
- if (semantic_parser) stack_offset = 0;
-
- fprintf(fguard, "\ncase %d:\n", nrules);
- if (!nolinesflag)
- fprintf (fguard, "#line %d \"%s\"\n", lineno, infile);
- putc('{', fguard);
-
- count = 0;
- c = getc(finput);
-
- while (brace_flag ? (count > 0) : (c != ';'))
- {
- switch (c)
- {
- case '\n':
- putc(c, fguard);
- lineno++;
- break;
-
- case '{':
- putc(c, fguard);
- brace_flag = 1;
- count++;
- break;
-
- case '}':
- putc(c, fguard);
- if (count > 0)
- count--;
- else
- {
- complain (_("unmatched %s"), "`}'");
- c = getc(finput); /* skip it */
- }
- break;
-
- case '\'':
- case '"':
- copy_string (finput, fguard, c);
- break;
-
- case '/':
- putc (c, fguard);
- c = getc (finput);
- if (c != '*' && c != '/')
- continue;
- copy_comment (finput, fguard, c);
- break;
-
- case '$':
- c = getc(finput);
- type_name = NULL;
-
- if (c == '<')
- {
- register 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;
-
- case '@':
- copy_at (finput, fguard, stack_offset);
- break;
-
- case EOF:
- fatal ("%s",
- _("unterminated %guard clause"));
-
- default:
- putc (c, fguard);
- }
-
- 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);
+ symbol_list *p;
+ if (current_rule->action_props.code)
+ grammar_midrule_action ();
+ p = grammar_symbol_append (sym, loc);
+ if (name)
+ assign_named_ref(p, name);
+ if (sym->status == undeclared || sym->status == used)
+ sym->status = needed;
}
+/* Attach an ACTION to the current rule. */
+void
+grammar_current_rule_action_append (const char *action, location loc,
+ named_ref *name, bool is_predicate)
+{
+ if (current_rule->action_props.code)
+ grammar_midrule_action ();
+ /* After all symbol declarations have been parsed, packgram invokes
+ code_props_translate_code. */
+ code_props_rule_action_init (¤t_rule->action_props, action, loc,
+ current_rule, name, is_predicate);
+}
-/* 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. */
+\f
+/*---------------------------------------------------------------.
+| Convert the rules into the representation using RRHS, RLHS and |
+| RITEM. |
+`---------------------------------------------------------------*/
static void
-copy_action (symbol_list *rule, int stack_offset)
+packgram (void)
{
- register int c;
- register int n;
- register int count;
- register char *type_name;
+ unsigned int itemno = 0;
+ rule_number ruleno = 0;
+ symbol_list *p = grammar;
- /* offset is always 0 if parser has already popped the stack pointer */
- if (semantic_parser)
- stack_offset = 0;
+ ritem = xnmalloc (nritems + 1, sizeof *ritem);
- fprintf (faction, "\ncase %d:\n", nrules);
- if (!nolinesflag)
- fprintf (faction, "#line %d \"%s\"\n", lineno, infile);
- putc ('{', faction);
+ /* This sentinel is used by build_relations in gram.c. */
+ *ritem++ = 0;
- count = 1;
- c = getc(finput);
+ rules = xnmalloc (nrules, sizeof *rules);
- while (count > 0)
+ while (p)
{
- while (c != '}')
+ int rule_length = 0;
+ symbol *ruleprec = p->ruleprec;
+ record_merge_function_type (p->merger, p->content.sym->type_name,
+ p->merger_declaration_location);
+ rules[ruleno].user_number = ruleno;
+ rules[ruleno].number = ruleno;
+ rules[ruleno].lhs = p->content.sym;
+ rules[ruleno].rhs = ritem + itemno;
+ rules[ruleno].prec = NULL;
+ rules[ruleno].dprec = p->dprec;
+ rules[ruleno].merger = p->merger;
+ rules[ruleno].precsym = NULL;
+ rules[ruleno].location = p->location;
+ rules[ruleno].useful = true;
+ rules[ruleno].action = p->action_props.code;
+ rules[ruleno].action_location = p->action_props.location;
+ rules[ruleno].is_predicate = p->action_props.is_predicate;
+
+ /* If the midrule's $$ is set or its $n is used, remove the `$' from the
+ symbol name so that it's a user-defined symbol so that the default
+ %destructor and %printer apply. */
+ if (p->midrule_parent_rule
+ && (p->action_props.is_value_used
+ || symbol_list_n_get (p->midrule_parent_rule,
+ p->midrule_parent_rhs_index)
+ ->action_props.is_value_used))
+ p->content.sym->tag += 1;
+
+ /* Don't check the generated rule 0. It has no action, so some rhs
+ symbols may appear unused, but the parsing algorithm ensures that
+ %destructor's are invoked appropriately. */
+ if (p != grammar)
+ grammar_rule_check (p);
+
+ for (p = p->next; p && p->content.sym; p = p->next)
{
- switch (c)
- {
- case '\n':
- putc(c, faction);
- lineno++;
- break;
-
- case '{':
- putc(c, faction);
- count++;
- break;
-
- case '\'':
- case '"':
- copy_string (finput, faction, c);
- break;
-
- case '/':
- putc (c, faction);
- c = getc (finput);
- if (c != '*' && c != '/')
- continue;
- copy_comment (finput, faction, c);
- break;
-
- case '$':
- c = getc(finput);
- type_name = NULL;
-
- if (c == '<')
- {
- register char *cp = token_buffer;
-
- while ((c = getc(finput)) != '>' && c > 0)
- {
- if (cp == token_buffer + maxtoken)
- cp = grow_token_buffer(cp);
-
- *cp++ = c;
- }
- *cp = 0;
- type_name = token_buffer;
- value_components_used = 1;
-
- c = getc(finput);
- }
- if (c == '$')
- {
- fprintf(faction, "yyval");
- if (!type_name)
- type_name = get_type_name(0, rule);
- if (type_name)
- fprintf(faction, ".%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(faction, "yyvsp[%d]", n - stack_offset);
- if (type_name)
- fprintf(faction, ".%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 '@':
- copy_at (finput, faction, stack_offset);
- break;
-
- case EOF:
- fatal (_("unmatched %s"), "`{'");
-
- default:
- putc(c, faction);
- }
-
- c = getc(finput);
+ ++rule_length;
+
+ /* Don't allow rule_length == INT_MAX, since that might
+ cause confusion with strtol if INT_MAX == LONG_MAX. */
+ if (rule_length == INT_MAX)
+ complain_at (rules[ruleno].location, fatal, _("rule is too long"));
+
+ /* item_number = symbol_number.
+ But the former needs to contain more: negative rule numbers. */
+ ritem[itemno++] =
+ symbol_number_as_item_number (p->content.sym->number);
+ /* A rule gets by default the precedence and associativity
+ of its last token. */
+ if (p->content.sym->class == token_sym && default_prec)
+ rules[ruleno].prec = p->content.sym;
}
- /* above loop exits when c is '}' */
-
- if (--count)
+ /* If this rule has a %prec,
+ the specified symbol's precedence replaces the default. */
+ if (ruleprec)
{
- putc(c, faction);
- c = getc(finput);
- }
- }
-
- fprintf(faction, ";\n break;}");
-}
-
-
+ rules[ruleno].precsym = ruleprec;
+ rules[ruleno].prec = ruleprec;
+ }
+ /* An item ends by the rule number (negated). */
+ ritem[itemno++] = rule_number_as_item_number (ruleno);
+ aver (itemno < ITEM_NUMBER_MAX);
+ ++ruleno;
+ aver (ruleno < RULE_NUMBER_MAX);
-/* generate a dummy symbol, a nonterminal,
-whose name cannot conflict with the user's names. */
+ if (p)
+ p = p->next;
+ }
-static bucket *
-gensym (void)
-{
- register bucket *sym;
+ aver (itemno == nritems);
- sprintf (token_buffer, "@%d", ++gensym_count);
- sym = getsym(token_buffer);
- sym->class = SNTERM;
- sym->value = nvars++;
- return sym;
+ if (trace_flag & trace_sets)
+ ritem_print (stderr);
}
+\f
+/*------------------------------------------------------------------.
+| Read in the grammar specification and record it in the format |
+| described in gram.h. All actions are copied into ACTION_OBSTACK, |
+| in each case forming the body of a C function (YYACTION) which |
+| contains a switch statement to decide which action to execute. |
+`------------------------------------------------------------------*/
-/* 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)
+void
+reader (void)
{
- register int t;
- register bucket *lhs = NULL;
- register symbol_list *p;
- register symbol_list *p1;
- register 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. */
-
- p1 = NULL;
+ /* Initialize the symbol table. */
+ symbols_new ();
- t = lex();
+ /* Construct the accept symbol. */
+ accept = symbol_get ("$accept", empty_location);
+ accept->class = nterm_sym;
+ accept->number = nvars++;
- 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 xactions = 0; /* JF for error checking */
- bucket *first_rhs = 0;
-
- if (t == IDENTIFIER)
- {
- lhs = symval;
-
- if (!start_flag)
- {
- startval = lhs;
- start_flag = 1;
- }
-
- t = lex();
- if (t != COLON)
- {
- complain (_("ill-formed rule: initial symbol not followed by colon"));
- unlex(t);
- }
- }
-
- if (nrules == 0 && t == BAR)
- {
- complain (_("grammar starts with vertical bar"));
- lhs = symval; /* BOGUS: use a random symval */
- }
- /* start a new rule and record its lhs. */
-
- nrules++;
- nitems++;
-
- record_rule_line ();
-
- p = NEW(symbol_list);
- p->sym = lhs;
-
- crule1 = p1;
- if (p1)
- p1->next = p;
- else
- grammar = p;
-
- p1 = p;
- crule = p;
-
- /* mark the rule's lhs as a nonterminal if not already so. */
-
- if (lhs->class == SUNKNOWN)
- {
- lhs->class = SNTERM;
- lhs->value = nvars;
- nvars++;
- }
- else if (lhs->class == STOKEN)
- complain (_("rule given for %s, which is a token"), lhs->tag);
-
- /* read the rhs of the rule. */
-
- for (;;)
- {
- t = lex();
- if (t == PREC)
- {
- t = lex();
- crule->ruleprec = symval;
- t = lex();
- }
-
- 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 (t == IDENTIFIER)
- {
- register bucket *ssave;
- register int t1;
-
- ssave = symval;
- t1 = lex();
- unlex(t1);
- symval = ssave;
- if (t1 == COLON) break;
-
- 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. */
- if (actionflag)
- {
- register 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();
-
- /* Make a new rule, whose body is empty,
- before the current one, so that the action
- just read can belong to it. */
- nrules++;
- nitems++;
- record_rule_line ();
- p = NEW(symbol_list);
- if (crule1)
- crule1->next = p;
- else grammar = p;
- p->sym = sdummy;
- 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->sym = sdummy;
- p1->next = p;
- p1 = p;
-
- actionflag = 0;
- }
-
- if (t == IDENTIFIER)
- {
- nitems++;
- p = NEW(symbol_list);
- p->sym = symval;
- p1->next = p;
- p1 = p;
- }
- else /* handle an action. */
- {
- copy_action(crule, rulelength);
- actionflag = 1;
- xactions++; /* JF */
- }
- rulelength++;
- } /* end of read rhs of rule */
-
- /* Put an empty link in the list to mark the end of this rule */
- p = NEW(symbol_list);
- p1->next = p;
- p1 = p;
-
- if (t == PREC)
- {
- complain (_("two @prec's in a row"));
- t = lex();
- crule->ruleprec = symval;
- t = lex();
- }
- if (t == GUARD)
- {
- if (! semantic_parser)
- complain ("%s",
- _("%guard present but %semantic_parser not specified"));
-
- copy_guard(crule, rulelength);
- t = lex();
- }
- else if (t == LEFT_CURLY)
- {
- /* This case never occurs -wjh */
- if (actionflag)
- complain (_("two actions at end of one rule"));
- copy_action(crule, rulelength);
- actionflag = 1;
- xactions++; /* -wjh */
- 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)
- {
- if (lhs->type_name == 0
- || first_rhs->type_name == 0
- || 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 : "");
- }
- /* 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();
- }
-#if 0
- /* 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 %
- thus they may swallow lots of intervening rules
-*/
- else if (t == TOKEN)
- {
- parse_token_decl(STOKEN, SNTERM);
- t = lex();
- }
- else if (t == NTERM)
- {
- parse_token_decl(SNTERM, STOKEN);
- t = lex();
- }
- else if (t == TYPE)
- {
- t = get_type();
- }
- else if (t == UNION)
- {
- parse_union_decl();
- t = lex();
- }
- else if (t == EXPECT)
- {
- parse_expect_decl();
- t = lex();
- }
- else if (t == START)
- {
- parse_start_decl();
- t = lex();
- }
-#endif
-
- else
- {
- complain (_("invalid input: %s"), token_buffer);
- t = lex();
- }
- }
-
- /* grammar has been read. Do some checking */
+ /* Construct the error token */
+ errtoken = symbol_get ("error", empty_location);
+ errtoken->class = token_sym;
+ errtoken->number = ntokens++;
- if (nsyms > MAXSHORT)
- fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
- MAXSHORT);
- if (nrules == 0)
- fatal (_("no rules in the input grammar"));
+ /* Construct a token that represents all undefined literal tokens.
+ It is always token number 2. */
+ undeftoken = symbol_get ("$undefined", empty_location);
+ undeftoken->class = token_sym;
+ undeftoken->number = ntokens++;
- 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");
- if (fdefines)
- fprintf(fdefines, "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
- }
+ gram_in = xfopen (grammar_file, "r");
- /* Report any undefined symbols and consider them nonterminals. */
+ gram__flex_debug = trace_flag & trace_scan;
+ gram_debug = trace_flag & trace_parse;
+ gram_scanner_initialize ();
+ gram_parse ();
+ prepare_percent_define_front_end_variables ();
- 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);
- bp->class = SNTERM;
- bp->value = nvars++;
- }
+ if (! complaint_issued)
+ check_and_convert_grammar ();
- ntokens = nsyms - nvars;
+ xfclose (gram_in);
}
-
static void
-record_rule_line (void)
+prepare_percent_define_front_end_variables (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)
-{
- 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);
-
- 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;
+ /* Set %define front-end variable defaults. */
+ muscle_percent_define_default ("lr.keep-unreachable-states", "false");
+ {
+ char *lr_type;
+ /* IELR would be a better default, but LALR is historically the
+ default. */
+ muscle_percent_define_default ("lr.type", "lalr");
+ lr_type = muscle_percent_define_get ("lr.type");
+ if (STRNEQ (lr_type, "canonical-lr"))
+ muscle_percent_define_default ("lr.default-reductions", "most");
+ else
+ muscle_percent_define_default ("lr.default-reductions", "accepting");
+ free (lr_type);
+ }
- default:
- return t;
- }
- }
+ /* Check %define front-end variables. */
+ {
+ static char const * const values[] = {
+ "lr.type", "lalr", "ielr", "canonical-lr", NULL,
+ "lr.default-reductions", "most", "consistent", "accepting", NULL,
+ NULL
+ };
+ muscle_percent_define_check_values (values);
+ }
}
-#endif
-/* Assign symbol numbers, and write definition of token names into
- fdefines. Set up vectors tags and sprec of names and precedences
- of symbols. */
+/*-------------------------------------------------------------.
+| Check the grammar that has just been read, and convert it to |
+| internal form. |
+`-------------------------------------------------------------*/
static void
-packsymbols (void)
+check_and_convert_grammar (void)
{
- register bucket *bp;
- register int tokno = 1;
- register int i;
- register int last_user_token_number;
- static char DOLLAR[] = "$";
-
- /* int lossage = 0; JF set but not used */
-
- tags = NEW2(nsyms + 1, char *);
- tags[0] = DOLLAR;
- user_toknums = NEW2(nsyms + 1, int);
- user_toknums[0] = 0;
-
- sprec = NEW2(nsyms, short);
- sassoc = NEW2(nsyms, short);
-
- max_user_token_number = 256;
- last_user_token_number = 256;
+ /* Grammar has been read. Do some checking. */
+ if (nrules == 0)
+ complain (fatal, _("no rules in the input grammar"));
- for (bp = firstsymbol; bp; bp = bp->next)
+ /* If the user did not define her ENDTOKEN, do it now. */
+ if (!endtoken)
{
- if (bp->class == SNTERM)
- {
- bp->value += ntokens;
- }
- else if (bp->alias)
- {
- /* this symbol and its alias are a single token defn.
- allocate a tokno, and assign to both check agreement of
- ->prec and ->assoc fields and make both the same */
- if (bp->value == 0)
- bp->value = bp->alias->value = tokno++;
-
- if (bp->prec != bp->alias->prec)
- {
- if (bp->prec != 0 && bp->alias->prec != 0
- && bp->user_token_number == SALIAS)
- complain (_("conflicting precedences for %s and %s"),
- bp->tag, bp->alias->tag);
- if (bp->prec != 0)
- bp->alias->prec = bp->prec;
- else
- bp->prec = bp->alias->prec;
- }
-
- if (bp->assoc != bp->alias->assoc)
- {
- if (bp->assoc != 0 && bp->alias->assoc != 0
- && bp->user_token_number == SALIAS)
- complain (_("conflicting assoc values for %s and %s"),
- bp->tag, bp->alias->tag);
- if (bp->assoc != 0)
- bp->alias->assoc = bp->assoc;
- else
- bp->assoc = bp->alias->assoc;
- }
-
- if (bp->user_token_number == SALIAS)
- continue; /* do not do processing below for SALIASs */
-
- }
- else /* bp->class == STOKEN */
- {
- bp->value = tokno++;
- }
-
- if (bp->class == STOKEN)
- {
- if (translations && !(bp->user_token_number))
- bp->user_token_number = ++last_user_token_number;
- if (bp->user_token_number > max_user_token_number)
- max_user_token_number = bp->user_token_number;
- }
-
- tags[bp->value] = bp->tag;
- user_toknums[bp->value] = bp->user_token_number;
- sprec[bp->value] = bp->prec;
- sassoc[bp->value] = bp->assoc;
-
+ endtoken = symbol_get ("$end", empty_location);
+ endtoken->class = token_sym;
+ endtoken->number = 0;
+ /* Value specified by POSIX. */
+ endtoken->user_token_number = 0;
}
- if (translations)
- {
- register int j;
-
- 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. */
- for (j = 0; j <= max_user_token_number; j++)
- token_translations[j] = 2;
+ /* Report any undefined symbols and consider them nonterminals. */
+ symbols_check_defined ();
- for (bp = firstsymbol; bp; bp = bp->next)
+ /* Find the start symbol if no %start. */
+ if (!start_flag)
+ {
+ symbol_list *node;
+ for (node = grammar;
+ node != NULL && symbol_is_dummy (node->content.sym);
+ node = node->next)
{
- if (bp->value >= ntokens)
- continue; /* non-terminal */
- if (bp->user_token_number == SALIAS)
- continue;
- 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;
+ for (node = node->next;
+ node != NULL && node->content.sym != NULL;
+ node = node->next)
+ ;
}
- }
-
- error_token_number = errtoken->value;
-
- if (! noparserflag)
- output_token_defines(ftable);
-
- if (startval->class == SUNKNOWN)
- fatal (_("the start symbol %s is undefined"), startval->tag);
- else if (startval->class == STOKEN)
- fatal (_("the start symbol %s is a token"), startval->tag);
-
- start_symbol = startval->value;
-
- if (definesflag)
- {
- output_token_defines(fdefines);
-
- if (!pure_parser)
- {
- if (spec_name_prefix)
- fprintf(fdefines, "\nextern YYSTYPE %slval;\n", spec_name_prefix);
- else
- fprintf(fdefines, "\nextern YYSTYPE yylval;\n");
- }
-
- if (semantic_parser)
- for (i = ntokens; i < nsyms; i++)
- {
- /* don't make these for dummy nonterminals made by gensym. */
- if (*tags[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);
- 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. */
-
-static void
-packgram (void)
-{
- register int itemno;
- register int ruleno;
- register symbol_list *p;
-/* register bucket *bp; JF unused */
-
- 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;
-
- itemno = 0;
- ruleno = 1;
-
- p = grammar;
- while (p)
- {
- rlhs[ruleno] = p->sym->value;
- rrhs[ruleno] = itemno;
- ruleprec = p->ruleprec;
-
- p = p->next;
- while (p && p->sym)
- {
- 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)
- {
- rprec[ruleno] = p->sym->prec;
- rassoc[ruleno] = p->sym->assoc;
- }
- if (p) p = p->next;
- }
+ aver (node != NULL);
+ grammar_start_symbol_set (node->content.sym,
+ node->content.sym->location);
+ }
+
+ /* Insert the initial rule, whose line is that of the first rule
+ (not that of the start symbol):
+
+ accept: %start EOF. */
+ {
+ symbol_list *p = symbol_list_sym_new (accept, empty_location);
+ p->location = grammar->location;
+ p->next = symbol_list_sym_new (startsymbol, empty_location);
+ p->next->next = symbol_list_sym_new (endtoken, empty_location);
+ p->next->next->next = symbol_list_sym_new (NULL, empty_location);
+ p->next->next->next->next = grammar;
+ nrules += 1;
+ nritems += 3;
+ grammar = p;
+ }
- /* If this rule has a %prec,
- the specified symbol's precedence replaces the default. */
- if (ruleprec)
- {
- rprec[ruleno] = ruleprec->prec;
- rassoc[ruleno] = ruleprec->assoc;
- rprecsym[ruleno] = ruleprec->value;
- }
+ aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
- ritem[itemno++] = -ruleno;
- ruleno++;
+ /* Assign the symbols their symbol numbers. Write #defines for the
+ token symbols into FDEFINES if requested. */
+ symbols_pack ();
+
+ /* Scan rule actions after invoking symbol_check_alias_consistency (in
+ symbols_pack above) so that token types are set correctly before the rule
+ action type checking.
+
+ Before invoking grammar_rule_check (in packgram below) on any rule, make
+ sure all actions have already been scanned in order to set `used' flags.
+ Otherwise, checking that a midrule's $$ should be set will not always work
+ properly because the check must forward-reference the midrule's parent
+ rule. For the same reason, all the `used' flags must be set before
+ checking whether to remove `$' from any midrule symbol name (also in
+ packgram). */
+ {
+ symbol_list *sym;
+ for (sym = grammar; sym; sym = sym->next)
+ code_props_translate_code (&sym->action_props);
+ }
- if (p) p = p->next;
- }
+ /* Convert the grammar into the format described in gram.h. */
+ packgram ();
- ritem[itemno] = 0;
+ /* The grammar as a symbol_list is no longer needed. */
+ symbol_list_free (grammar);
}
projects / bison.git / blobdiff