-/* Input parser for bison
- Copyright 1984, 1986, 1989, 1992, 1998, 2000
- Free Software Foundation, Inc.
+/* Input parser for Bison
+
+ Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
+ 2005, 2006 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
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. */
-
+ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
+#include <config.h>
#include "system.h"
-#include "obstack.h"
-#include "quotearg.h"
-#include "quote.h"
-#include "getargs.h"
+
+#include <quotearg.h>
+
+#include "complain.h"
+#include "conflicts.h"
#include "files.h"
-#include "xalloc.h"
-#include "symtab.h"
-#include "lex.h"
+#include "getargs.h"
#include "gram.h"
-#include "complain.h"
+#include "muscle_tab.h"
#include "output.h"
#include "reader.h"
-#include "conflicts.h"
-
-/* Number of slots allocated (but not necessarily used yet) in `rline' */
-static int rline_allocated;
-
-typedef struct symbol_list
-{
- struct symbol_list *next;
- bucket *sym;
- bucket *ruleprec;
-}
-symbol_list;
-
-int lineno;
-char **tags;
-short *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;
+#include "symlist.h"
+#include "symtab.h"
-/* Nonzero if %union has been seen. */
-static int typed;
+static void check_and_convert_grammar (void);
-/* Incremented for each %left, %right or %nonassoc seen */
-static int lastprec;
+static symbol_list *grammar = NULL;
+static bool start_flag = false;
+merger_list *merge_functions;
-/* Incremented for each generated symbol */
-static int gensym_count;
+/* Was %union seen? */
+bool typed = false;
-static bucket *errtoken;
-static bucket *undeftoken;
+/* Should rules have a default precedence? */
+bool default_prec = true;
\f
+/*-----------------------.
+| Set the start symbol. |
+`-----------------------*/
-/*===================\
-| Low level lexing. |
-\===================*/
-
-static void
-skip_to_char (int target)
+void
+grammar_start_symbol_set (symbol *sym, location loc)
{
- int c;
- if (target == '\n')
- complain (_(" Skipping to next \\n"));
+ if (start_flag)
+ complain_at (loc, _("multiple %s declarations"), "%start");
else
- complain (_(" Skipping to next %c"), target);
-
- do
- c = skip_white_space ();
- while (c != target && c != EOF);
- if (c != EOF)
- ungetc (c, finput);
-}
-
-
-/*---------------------------------------------------------.
-| Read a signed integer from STREAM and return its value. |
-`---------------------------------------------------------*/
-
-static inline int
-read_signed_integer (FILE *stream)
-{
- int c = getc (stream);
- int sign = 1;
- int n = 0;
-
- if (c == '-')
- {
- c = getc (stream);
- sign = -1;
- }
-
- while (isdigit (c))
- {
- n = 10 * n + (c - '0');
- c = getc (stream);
- }
-
- ungetc (c, stream);
-
- return sign * n;
-}
-\f
-/*--------------------------------------------------------------.
-| 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)
-{
- int i;
- 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++;
+ start_flag = true;
+ startsymbol = sym;
+ startsymbol_location = loc;
}
-
- return rp->sym->type_name;
-}
-\f
-/*-----------------------------------------------------------------.
-| Dump the string from FIN to FOUT and OOUT if non null. MATCH is |
-| the delimiter of the string (either ' or "). |
-`-----------------------------------------------------------------*/
-
-static inline void
-copy_string (FILE *fin, FILE *fout, struct obstack *oout, int match)
-{
- int c;
-
- if (fout)
- putc (match, fout);
- if (oout)
- obstack_1grow (oout, match);
-
- c = getc (fin);
-
- while (c != match)
- {
- if (c == EOF)
- fatal (_("unterminated string at end of file"));
- if (c == '\n')
- {
- complain (_("unterminated string"));
- ungetc (c, fin);
- c = match; /* invent terminator */
- continue;
- }
-
- if (fout)
- putc (c, fout);
- if (oout)
- obstack_1grow (oout, c);
-
- if (c == '\\')
- {
- c = getc (fin);
- if (c == EOF)
- fatal (_("unterminated string at end of file"));
- if (fout)
- putc (c, fout);
- if (oout)
- obstack_1grow (oout, c);
-
- if (c == '\n')
- lineno++;
- }
-
- c = getc (fin);
- }
-
- if (fout)
- putc (c, fout);
- if (oout)
- obstack_1grow (oout, c);
}
/*----------------------------------------------------------------.
-| Dump the wannabee comment from IN to OUT1 and OUT2. In fact we |
-| just saw a `/', which might or might not be a comment. In any |
-| case, copy what we saw. |
-| |
-| OUT2 might be NULL. |
+| There are two prologues: one before %union, one after. Augment |
+| the current one. |
`----------------------------------------------------------------*/
-static inline void
-copy_comment2 (FILE *fin, FILE *out1,
- struct obstack *oout2, struct obstack *oout)
+void
+prologue_augment (const char *prologue, location loc)
{
- int cplus_comment;
- int ended;
- int c;
-
- /* We read a `/', output it. */
- if (out1)
- putc ('/', out1);
- if (oout)
- obstack_1grow (oout, '/');
- if (oout2)
- obstack_1grow (oout2, '/');
-
- switch ((c = getc (fin)))
- {
- case '/':
- cplus_comment = 1;
- break;
- case '*':
- cplus_comment = 0;
- break;
- default:
- ungetc (c, fin);
- return;
- }
-
- if (out1)
- putc (c, out1);
- if (oout)
- obstack_1grow (oout, c);
- if (oout2)
- obstack_1grow (oout2, c);
- c = getc (fin);
-
- ended = 0;
- while (!ended)
- {
- if (!cplus_comment && c == '*')
- {
- while (c == '*')
- {
- if (out1)
- putc (c, out1);
- if (oout)
- obstack_1grow (oout, c);
- if (oout2)
- obstack_1grow (oout2, c);
- c = getc (fin);
- }
-
- if (c == '/')
- {
- if (out1)
- putc (c, out1);
- if (oout)
- obstack_1grow (oout, c);
- if (oout2)
- obstack_1grow (oout2, c);
- ended = 1;
- }
- }
- else if (c == '\n')
- {
- lineno++;
- if (out1)
- putc (c, out1);
- if (oout)
- obstack_1grow (oout, c);
- if (oout2)
- obstack_1grow (oout2, c);
- if (cplus_comment)
- ended = 1;
- else
- c = getc (fin);
- }
- else if (c == EOF)
- fatal (_("unterminated comment"));
- else
- {
- if (out1)
- putc (c, out1);
- if (oout)
- obstack_1grow (oout, c);
- if (oout2)
- obstack_1grow (oout2, c);
- c = getc (fin);
- }
- }
+ struct obstack *oout =
+ !typed ? &pre_prologue_obstack : &post_prologue_obstack;
+
+ obstack_fgrow1 (oout, "]b4_syncline(%d, [[", loc.start.line);
+ MUSCLE_OBSTACK_SGROW (oout,
+ quotearg_style (c_quoting_style, loc.start.file));
+ obstack_sgrow (oout, "]])[\n");
+ obstack_sgrow (oout, prologue);
}
+\f
/*-------------------------------------------------------------------.
-| Dump the comment (actually the current string starting with a `/') |
-| from FIN to FOUT. |
+| Return the merger index for a merging function named NAME, whose |
+| arguments have type TYPE. Records the function, if new, in |
+| MERGER_LIST. |
`-------------------------------------------------------------------*/
-static inline void
-copy_comment (FILE *fin, FILE *fout, struct obstack *oout)
+static int
+get_merge_function (uniqstr name, uniqstr type, location loc)
{
- copy_comment2 (fin, fout, NULL, oout);
-}
+ merger_list *syms;
+ merger_list head;
+ int n;
+ if (! glr_parser)
+ return 0;
-/*-----------------------------------------------------------------.
-| 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 `$0' with |
-| respect to the top of the stack. |
-`-----------------------------------------------------------------*/
+ if (type == NULL)
+ type = uniqstr_new ("");
-static inline void
-copy_at (FILE *fin, FILE *fout, struct obstack *oout, int stack_offset)
-{
- int c;
-
- c = getc (fin);
- if (c == '$')
- {
- if (fout)
- fprintf (fout, "yyloc");
- if (oout)
- obstack_grow_string (oout, "yyloc");
- locations_flag = 1;
- }
- else if (isdigit (c) || c == '-')
- {
- int n;
- char buf[4096];
-
- ungetc (c, fin);
- n = read_signed_integer (fin);
-
- sprintf (buf, "yylsp[%d]", n - stack_offset);
- if (fout)
- fputs (buf, fout);
- if (oout)
- obstack_grow (oout, buf, strlen (buf));
- locations_flag = 1;
- }
- else
- {
- char buf[] = "@c";
- buf[1] = c;
- complain (_("%s is invalid"), quote (buf));
- }
+ 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);
+ syms->next->type = uniqstr_new (type);
+ syms->next->next = NULL;
+ merge_functions = head.next;
+ }
+ else if (!UNIQSTR_EQ (type, syms->next->type))
+ warn_at (loc, _("result type clash on merge function %s: <%s> != <%s>"),
+ name, type, syms->next->type);
+ return n;
}
+/*--------------------------------------.
+| Free all merge-function definitions. |
+`--------------------------------------*/
-/*-------------------------------------------------------------------.
-| FIN is pointing to a wannabee semantic value (i.e., a `$'). |
-| |
-| Possible inputs: $[<TYPENAME>]($|integer) |
-| |
-| Output to FOUT a reference to this semantic value. STACK_OFFSET is |
-| the number of values in the current rule so far, which says where |
-| to find `$0' with respect to the top of the stack. |
-`-------------------------------------------------------------------*/
-
-static inline void
-copy_dollar (FILE *fin, FILE *fout, struct obstack *oout,
- symbol_list *rule, int stack_offset)
+void
+free_merger_functions (void)
{
- int c = getc (fin);
- char *type_name = NULL;
-
- /* Get the type name if explicit. */
- if (c == '<')
- {
- read_type_name (fin);
- type_name = token_buffer;
- value_components_used = 1;
- c = getc (fin);
- }
-
- if (c == '$')
- {
- if (fout)
- fputs ("yyval", fout);
- if (oout)
- obstack_grow_string (oout, "yyval");
-
- if (!type_name)
- type_name = get_type_name (0, rule);
- if (type_name)
- {
- if (fout)
- fprintf (fout, ".%s", type_name);
- if (oout)
- obstack_fgrow1 (oout, ".%s", type_name);
- }
- if (!type_name && typed)
- complain (_("$$ of `%s' has no declared type"),
- rule->sym->tag);
- }
- else if (isdigit (c) || c == '-')
+ merger_list *L0 = merge_functions;
+ while (L0)
{
- int n;
- ungetc (c, fin);
- n = read_signed_integer (fin);
-
- if (!type_name && n > 0)
- type_name = get_type_name (n, rule);
-
- if (fout)
- fprintf (fout, "yyvsp[%d]", n - stack_offset);
- if (oout)
- obstack_fgrow1 (oout, "yyvsp[%d]", n - stack_offset);
-
- if (type_name)
- {
- if (fout)
- fprintf (fout, ".%s", type_name);
- if (oout)
- obstack_fgrow1 (oout, ".%s", type_name);
- }
- if (!type_name && typed)
- complain (_("$%d of `%s' has no declared type"),
- n, rule->sym->tag);
- }
- else
- {
- char buf[] = "$c";
- buf[1] = c;
- complain (_("%s is invalid"), quote (buf));
+ merger_list *L1 = L0->next;
+ free (L0);
+ L0 = L1;
}
}
+
\f
/*-------------------------------------------------------------------.
-| Copy the contents of a `%{ ... %}' into the definitions file. The |
-| `%{' has already been read. Return after reading the `%}'. |
+| 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. |
`-------------------------------------------------------------------*/
-static void
-copy_definition (void)
-{
- int c;
- /* -1 while reading a character if prev char was %. */
- int after_percent;
-
- if (!no_lines_flag)
- obstack_fgrow2 (&attrs_obstack, "#line %d %s\n",
- lineno, quotearg_style (c_quoting_style, infile));
-
- after_percent = 0;
-
- c = getc (finput);
-
- for (;;)
- {
- switch (c)
- {
- case '\n':
- obstack_1grow (&attrs_obstack, c);
- lineno++;
- break;
-
- case '%':
- after_percent = -1;
- break;
-
- case '\'':
- case '"':
- copy_string (finput, 0, &attrs_obstack, c);
- break;
-
- case '/':
- copy_comment (finput, 0, &attrs_obstack);
- break;
-
- case EOF:
- fatal ("%s", _("unterminated `%{' definition"));
-
- default:
- obstack_1grow (&attrs_obstack, c);
- }
-
- c = getc (finput);
-
- if (after_percent)
- {
- if (c == '}')
- return;
- obstack_1grow (&attrs_obstack, '%');
- }
- after_percent = 0;
- }
-}
-
-
-/*-------------------------------------------------------------------.
-| Parse what comes after %token or %nterm. For %token, WHAT_IS is |
-| token_sym and WHAT_IS_NOT is nterm_sym. For %nterm, the arguments |
-| are reversed. |
-`-------------------------------------------------------------------*/
+/* The (currently) last symbol of GRAMMAR. */
+static symbol_list *grammar_end = NULL;
+/* Append SYM to the grammar. */
static void
-parse_token_decl (symbol_class what_is, symbol_class what_is_not)
+grammar_symbol_append (symbol *sym, location loc)
{
- int token = 0;
- char *typename = 0;
-
- /* The symbol being defined. */
- struct bucket *symbol = NULL;
+ symbol_list *p = symbol_list_new (sym, loc);
- /* After `%token' and `%nterm', any number of symbols maybe be
- defined. */
- for (;;)
- {
- int tmp_char = ungetc (skip_white_space (), finput);
-
- /* `%' (for instance from `%token', or from `%%' etc.) is the
- only valid means to end this declaration. */
- 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)
- {
- typename = xstrdup (token_buffer);
- value_components_used = 1;
- symbol = NULL;
- }
- else if (token == IDENTIFIER && *symval->tag == '\"' && symbol)
- {
- if (symval->alias)
- warn (_("symbol `%s' used more than once as a literal string"),
- symval->tag);
- else if (symbol->alias)
- warn (_("symbol `%s' given more than one literal string"),
- symbol->tag);
- else
- {
- symval->class = token_sym;
- symval->type_name = typename;
- symval->user_token_number = symbol->user_token_number;
- symbol->user_token_number = SALIAS;
- symval->alias = symbol;
- symbol->alias = symval;
- /* symbol and symval combined are only one symbol */
- nsyms--;
- }
- translations = 1;
- symbol = NULL;
- }
- 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 == nterm_sym && oldclass != nterm_sym)
- 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 == token_sym) ? "%token" : "%nterm");
- skip_to_char ('%');
- }
- }
-
-}
-
-
-/*------------------------------.
-| Parse what comes after %start |
-`------------------------------*/
-
-static void
-parse_start_decl (void)
-{
- if (start_flag)
- complain (_("multiple %s declarations"), "%start");
- if (lex () != IDENTIFIER)
- complain (_("invalid %s declaration"), "%start");
+ if (grammar_end)
+ grammar_end->next = p;
else
- {
- start_flag = 1;
- startval = symval;
- }
-}
-
-/*-----------------------------------------------------------.
-| read in a %type declaration and record its information for |
-| get_type_name to access |
-`-----------------------------------------------------------*/
+ grammar = p;
-static void
-parse_type_decl (void)
-{
- char *name;
-
- if (lex () != TYPENAME)
- {
- complain ("%s", _("%type declaration has no <typename>"));
- skip_to_char ('%');
- return;
- }
-
- name = xstrdup (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:
- 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);
-
- break;
+ grammar_end = p;
- default:
- complain (_("invalid %%type declaration due to item: %s"),
- token_buffer);
- skip_to_char ('%');
- }
- }
+ /* A null SYM stands for an end of rule; it is not an actual
+ part of it. */
+ if (sym)
+ ++nritems;
}
+/* 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). */
+symbol_list *current_rule = NULL;
+static symbol_list *previous_rule_end = NULL;
-/*----------------------------------------------------------------.
-| Read in a %left, %right or %nonassoc declaration and record its |
-| information. |
-`----------------------------------------------------------------*/
+/*----------------------------------------------.
+| Create a new rule for LHS in to the GRAMMAR. |
+`----------------------------------------------*/
-static void
-parse_assoc_decl (associativity assoc)
+void
+grammar_current_rule_begin (symbol *lhs, location loc)
{
- char *name = NULL;
- int prev = 0;
-
- lastprec++; /* Assign a new precedence level, never 0. */
-
- for (;;)
+ if (!start_flag)
{
- 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:
- name = xstrdup (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 == nterm_sym)
- complain (_("symbol %s redefined"), symval->tag);
- symval->class = token_sym;
- 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;
-
+ startsymbol = lhs;
+ startsymbol_location = loc;
+ start_flag = true;
}
-}
-
-
-
-/*--------------------------------------------------------------.
-| Copy the union declaration into ATTRS_OBSTACK (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)
-{
- int c;
- int count = 0;
- if (typed)
- complain (_("multiple %s declarations"), "%union");
+ /* Start a new rule and record its lhs. */
+ ++nrules;
+ previous_rule_end = grammar_end;
+ grammar_symbol_append (lhs, loc);
+ current_rule = grammar_end;
- typed = 1;
-
- if (!no_lines_flag)
- obstack_fgrow2 (&attrs_obstack, "\n#line %d %s\n",
- lineno, quotearg_style (c_quoting_style, infile));
- else
- obstack_1grow (&attrs_obstack, '\n');
-
- obstack_grow_string (&attrs_obstack, "typedef union");
- if (defines_flag)
- obstack_grow_string (&defines_obstack, "typedef union");
-
- c = getc (finput);
-
- while (c != EOF)
+ /* Mark the rule's lhs as a nonterminal if not already so. */
+ if (lhs->class == unknown_sym)
{
- obstack_1grow (&attrs_obstack, c);
- if (defines_flag)
- obstack_1grow (&defines_obstack, c);
-
- switch (c)
- {
- case '\n':
- lineno++;
- break;
-
- case '/':
- copy_comment2 (finput, 0, &defines_obstack, &attrs_obstack);
- break;
-
- case '{':
- count++;
- break;
-
- case '}':
- if (count == 0)
- complain (_("unmatched %s"), "`}'");
- count--;
- if (count <= 0)
- {
- obstack_grow_string (&attrs_obstack, " YYSTYPE;\n");
- if (defines_flag)
- obstack_grow_string (&defines_obstack, " YYSTYPE;\n");
- /* JF don't choke on trailing semi */
- c = skip_white_space ();
- if (c != ';')
- ungetc (c, finput);
- return;
- }
- }
-
- c = getc (finput);
+ lhs->class = nterm_sym;
+ lhs->number = nvars;
+ ++nvars;
}
+ else if (lhs->class == token_sym)
+ complain_at (loc, _("rule given for %s, which is a token"), lhs->tag);
}
-/*-------------------------------------------------------.
-| Parse the declaration %expect N which says to expect N |
-| shift-reduce conflicts. |
-`-------------------------------------------------------*/
-
-static void
-parse_expect_decl (void)
-{
- int c = skip_white_space ();
- ungetc (c, finput);
-
- if (!isdigit (c))
- complain (_("argument of %%expect is not an integer"));
- else
- expected_conflicts = read_signed_integer (finput);
-}
-
-
-/*-------------------------------------------------------------------.
-| 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 |
-`-------------------------------------------------------------------*/
+/*-----------------------------------------------------------------.
+| A symbol is typed if it has a declared %type, or if it is a |
+| mid-rule symbol (i.e., the generated LHS replacing a mid-rule |
+| action) that was assigned to, as in `exp: { $$ = 1; } { $$ = $1; |
+| }'. |
+`-----------------------------------------------------------------*/
-static void
-parse_thong_decl (void)
+static bool
+symbol_typed_p (const symbol_list *s)
{
- int token;
- struct bucket *symbol;
- char *typename = 0;
- int usrtoknum;
-
- translations = 1;
- token = lex (); /* fetch typename or first token */
- if (token == TYPENAME)
- {
- typename = xstrdup (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 = token_sym;
- 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 = token_sym;
- symval->type_name = typename;
- symval->user_token_number = usrtoknum;
-
- symval->alias = symbol;
- symbol->alias = symval;
-
- /* symbol and symval combined are only one symbol. */
- nsyms--;
+ return (s->sym->type_name
+ || (s->midrule && s->midrule->used));
}
-
/*----------------------------------------------------------------.
-| Read from finput until `%%' is seen. Discard the `%%'. Handle |
-| any `%' declarations, and copy the contents of any `%{ ... %}' |
-| groups to ATTRS_OBSTACK. |
+| Check that the rule R is properly defined. For instance, there |
+| should be no type clash on the default action. |
`----------------------------------------------------------------*/
static void
-read_declarations (void)
+grammar_rule_check (const symbol_list *r)
{
- int c;
- int tok;
+ /* Type check.
- for (;;)
- {
- c = skip_white_space ();
+ If there is an action, then there is nothing we can do: the user
+ is allowed to shoot herself in the foot.
- if (c == '%')
+ Don't worry about the default action if $$ is untyped, since $$'s
+ value can't be used. */
+ if (!r->action && r->sym->type_name)
+ {
+ symbol *first_rhs = r->next->sym;
+ /* If $$ is being set in default way, report if any type mismatch. */
+ if (first_rhs)
{
- tok = parse_percent_token ();
-
- switch (tok)
- {
- case TWO_PERCENTS:
- return;
-
- case PERCENT_LEFT_CURLY:
- copy_definition ();
- break;
-
- case TOKEN:
- parse_token_decl (token_sym, nterm_sym);
- break;
-
- case NTERM:
- parse_token_decl (nterm_sym, token_sym);
- 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)
- fguard = xfopen (guardfile, "w");
- semantic_parser = 1;
- break;
-
- case PURE_PARSER:
- pure_parser = 1;
- break;
-
- case NOOP:
- break;
-
- default:
- complain (_("unrecognized: %s"), token_buffer);
- skip_to_char ('%');
- }
+ char const *lhs_type = r->sym->type_name;
+ const char *rhs_type =
+ first_rhs->type_name ? first_rhs->type_name : "";
+ if (!UNIQSTR_EQ (lhs_type, rhs_type))
+ warn_at (r->location,
+ _("type clash on default action: <%s> != <%s>"),
+ lhs_type, rhs_type);
}
- else if (c == EOF)
- fatal (_("no input grammar"));
+ /* Warn if there is no default for $$ but we need one. */
else
- {
- char buf[] = "c";
- buf[0] = c;
- complain (_("unknown character: %s"), quote (buf));
- skip_to_char ('%');
+ warn_at (r->location,
+ _("empty rule for typed nonterminal, and no action"));
+ }
+
+ /* Check that typed symbol values are used. */
+ {
+ symbol_list const *l = r;
+ int n = 0;
+ for (; l && l->sym; l = l->next, ++n)
+ if (! (l->used
+ || !symbol_typed_p (l)
+ /* The default action, $$ = $1, `uses' both. */
+ || (!r->action && (n == 0 || n == 1))))
+ {
+ if (n)
+ warn_at (r->location, _("unused value: $%d"), n);
+ else
+ warn_at (r->location, _("unset value: $$"));
}
- }
+ }
}
-\f
-/*-------------------------------------------------------------------.
-| 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)
-{
- int c;
- int count;
- char buf[4096];
- /* offset is always 0 if parser has already popped the stack pointer */
- if (semantic_parser)
- stack_offset = 0;
-
- sprintf (buf, "\ncase %d:\n", nrules);
- obstack_grow (&action_obstack, buf, strlen (buf));
-
- if (!no_lines_flag)
- {
- sprintf (buf, "#line %d %s\n",
- lineno, quotearg_style (c_quoting_style, infile));
- obstack_grow (&action_obstack, buf, strlen (buf));
- }
- obstack_1grow (&action_obstack, '{');
- count = 1;
- c = getc (finput);
+/*-------------------------------------.
+| End the currently being grown rule. |
+`-------------------------------------*/
- while (count > 0)
- {
- while (c != '}')
- {
- switch (c)
- {
- case '\n':
- obstack_1grow (&action_obstack, c);
- lineno++;
- break;
-
- case '{':
- obstack_1grow (&action_obstack, c);
- count++;
- break;
-
- case '\'':
- case '"':
- copy_string (finput, 0, &action_obstack, c);
- break;
-
- case '/':
- copy_comment (finput, 0, &action_obstack);
- break;
-
- case '$':
- copy_dollar (finput, 0, &action_obstack,
- rule, stack_offset);
- break;
-
- case '@':
- copy_at (finput, 0, &action_obstack,
- stack_offset);
- break;
-
- case EOF:
- fatal (_("unmatched %s"), "`{'");
-
- default:
- obstack_1grow (&action_obstack, c);
- }
-
- c = getc (finput);
- }
+void
+grammar_current_rule_end (location loc)
+{
+ /* 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;
+ grammar_rule_check (current_rule);
+}
- /* above loop exits when c is '}' */
- if (--count)
- {
- obstack_1grow (&action_obstack, c);
- c = getc (finput);
- }
- }
-
- obstack_grow_string (&action_obstack, ";\n break;}");
-}
-\f
/*-------------------------------------------------------------------.
-| 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. |
+| 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. |
`-------------------------------------------------------------------*/
static void
-copy_guard (symbol_list *rule, int stack_offset)
+grammar_midrule_action (void)
{
- int c;
- int count;
- 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 (!no_lines_flag)
- fprintf (fguard, "#line %d %s\n",
- lineno, quotearg_style (c_quoting_style, 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, 0, c);
- break;
-
- case '/':
- copy_comment (finput, fguard, 0);
- break;
-
- case '$':
- copy_dollar (finput, fguard, 0, rule, stack_offset);
- break;
-
- case '@':
- copy_at (finput, fguard, 0, 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);
- }
+ /* 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_location;
+ symbol *dummy = dummy_symbol_get (dummy_location);
+ symbol_list *midrule = symbol_list_new (dummy, dummy_location);
+
+ /* 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;
+ midrule->action = current_rule->action;
+ midrule->action_location = dummy_location;
+ current_rule->action = NULL;
+ /* If $$ was used in the action, the LHS of the enclosing rule was
+ incorrectly flagged as used. */
+ midrule->used = current_rule->used;
+ current_rule->used = false;
+
+ if (previous_rule_end)
+ previous_rule_end->next = midrule;
else
- ungetc (c, finput);
-}
-\f
+ grammar = midrule;
-static void
-record_rule_line (void)
-{
- /* Record each rule's source line number in rline table. */
+ /* End the dummy's rule. */
+ midrule->next = symbol_list_new (NULL, dummy_location);
+ grammar_rule_check (midrule);
+ midrule->next->next = current_rule;
- if (nrules >= rline_allocated)
- {
- rline_allocated = nrules * 2;
- rline = XREALLOC (rline, short, rline_allocated);
- }
- rline[nrules] = lineno;
-}
+ previous_rule_end = midrule->next;
+ /* 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);
+ grammar_end->midrule = midrule;
+}
-/*-------------------------------------------------------------------.
-| Generate a dummy symbol, a nonterminal, whose name cannot conflict |
-| with the user's names. |
-`-------------------------------------------------------------------*/
+/* Set the precedence symbol of the current rule to PRECSYM. */
-static bucket *
-gensym (void)
+void
+grammar_current_rule_prec_set (symbol *precsym, location loc)
{
- bucket *sym;
-
- sprintf (token_buffer, "@%d", ++gensym_count);
- sym = getsym (token_buffer);
- sym->class = nterm_sym;
- sym->value = nvars++;
- return sym;
+ if (current_rule->ruleprec)
+ complain_at (loc, _("only one %s allowed per rule"), "%prec");
+ current_rule->ruleprec = precsym;
}
-#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 |
-`------------------------------------------------------------------*/
+/* Attach dynamic precedence DPREC to the current rule. */
-static int
-get_type (void)
+void
+grammar_current_rule_dprec_set (int dprec, location loc)
{
- int k;
- int t;
- char *name;
-
- t = lex ();
-
- if (t != TYPENAME)
- {
- complain (_("invalid %s declaration"), "%type");
- return t;
- }
-
- name = xstrdup (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;
- }
- }
+ if (! glr_parser)
+ warn_at (loc, _("%s affects only GLR parsers"), "%dprec");
+ if (dprec <= 0)
+ complain_at (loc, _("%s must be followed by positive number"), "%dprec");
+ else if (current_rule->dprec != 0)
+ complain_at (loc, _("only one %s allowed per rule"), "%dprec");
+ current_rule->dprec = dprec;
}
-#endif
-\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 guards and actions are copied out to the appropriate files, |
-| labelled by the rule number they apply to. |
-`------------------------------------------------------------------*/
+/* Attach a merge function NAME with argument type TYPE to current
+ rule. */
-static void
-readgram (void)
+void
+grammar_current_rule_merge_set (uniqstr name, location loc)
{
- int t;
- bucket *lhs = NULL;
- symbol_list *p;
- symbol_list *p1;
- bucket *bp;
-
- /* Points to first symbol_list of current rule. its symbol is the
- lhs of the rule. */
- symbol_list *crule;
- /* Points to the symbol_list preceding crule. */
- symbol_list *crule1;
-
- p1 = NULL;
-
- t = lex ();
-
- while (t != TWO_PERCENTS && t != ENDFILE)
- {
- if (t == IDENTIFIER || t == BAR)
- {
- int action_flag = 0;
- /* Number of symbols in rhs of this rule so far */
- int rulelength = 0;
- 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 = XCALLOC (symbol_list, 1);
- 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 == unknown_sym)
- {
- lhs->class = nterm_sym;
- lhs->value = nvars;
- nvars++;
- }
- else if (lhs->class == token_sym)
- 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)
- {
- bucket *ssave;
- 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 (action_flag)
- {
- 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 = XCALLOC (symbol_list, 1);
- if (crule1)
- crule1->next = p;
- else
- grammar = p;
- p->sym = sdummy;
- crule1 = XCALLOC (symbol_list, 1);
- p->next = crule1;
- crule1->next = crule;
-
- /* Insert the dummy generated by that rule into this
- rule. */
- nitems++;
- p = XCALLOC (symbol_list, 1);
- p->sym = sdummy;
- p1->next = p;
- p1 = p;
-
- action_flag = 0;
- }
-
- if (t == IDENTIFIER)
- {
- nitems++;
- p = XCALLOC (symbol_list, 1);
- p->sym = symval;
- p1->next = p;
- p1 = p;
- }
- else /* handle an action. */
- {
- copy_action (crule, rulelength);
- action_flag = 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 = XCALLOC (symbol_list, 1);
- 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 (_("%%guard present but %%semantic_parser not specified"));
-
- copy_guard (crule, rulelength);
- t = lex ();
- }
- else if (t == LEFT_CURLY)
- {
- /* This case never occurs -wjh */
- if (action_flag)
- complain (_("two actions at end of one rule"));
- copy_action (crule, rulelength);
- action_flag = 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 (token_sym, nterm_sym);
- t = lex ();
- }
- else if (t == NTERM)
- {
- parse_token_decl (nterm_sym, token_sym);
- 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 */
-
- if (nsyms > MAXSHORT)
- fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
- MAXSHORT);
- if (nrules == 0)
- fatal (_("no rules in the input grammar"));
-
- /* JF put out same default YYSTYPE as YACC does */
- if (typed == 0
- && !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. */
- obstack_grow_string (&attrs_obstack,
- "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
- if (defines_flag)
- obstack_grow_string (&defines_obstack, "\
-#ifndef YYSTYPE\n\
-# define YYSTYPE int\n\
-#endif\n");
- }
-
- /* Report any undefined symbols and consider them nonterminals. */
-
- for (bp = firstsymbol; bp; bp = bp->next)
- if (bp->class == unknown_sym)
- {
- complain (_
- ("symbol %s is used, but is not defined as a token and has no rules"),
- bp->tag);
- bp->class = nterm_sym;
- bp->value = nvars++;
- }
-
- ntokens = nsyms - nvars;
+ if (! glr_parser)
+ warn_at (loc, _("%s affects only GLR parsers"), "%merge");
+ if (current_rule->merger != 0)
+ complain_at (loc, _("only one %s allowed per rule"), "%merge");
+ current_rule->merger =
+ get_merge_function (name, current_rule->sym->type_name, loc);
}
-\f
-/*--------------------------------------------------------------.
-| For named tokens, but not literal ones, define the name. The |
-| value is the user token number. |
-`--------------------------------------------------------------*/
-static void
-output_token_defines (struct obstack *oout)
-{
- bucket *bp;
- char *cp, *symbol;
- char c;
+/* Attach SYM to the current rule. If needed, move the previous
+ action as a mid-rule action. */
- 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;
-
- obstack_fgrow2 (oout, "#define\t%s\t%d\n",
- symbol,
- ((translations && !raw_flag)
- ? bp->user_token_number : bp->value));
- if (semantic_parser)
- obstack_fgrow2 (oout, "#define\tT%s\t%d\n", symbol, bp->value);
- }
-
- obstack_1grow (oout, '\n');
+void
+grammar_current_rule_symbol_append (symbol *sym, location loc)
+{
+ if (current_rule->action)
+ grammar_midrule_action ();
+ grammar_symbol_append (sym, loc);
}
+/* Attach an ACTION to the current rule. If needed, move the previous
+ action as a mid-rule action. */
-/*------------------------------------------------------------------.
-| 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)
+void
+grammar_current_rule_action_append (const char *action, location loc)
{
- bucket *bp;
- int tokno = 1;
- int i;
- int last_user_token_number;
- static char DOLLAR[] = "$";
-
- /* int lossage = 0; JF set but not used */
-
- tags = XCALLOC (char *, nsyms + 1);
- tags[0] = DOLLAR;
- user_toknums = XCALLOC (short, nsyms + 1);
- user_toknums[0] = 0;
-
- sprec = XCALLOC (short, nsyms);
- sassoc = XCALLOC (short, nsyms);
-
- max_user_token_number = 256;
- last_user_token_number = 256;
-
- for (bp = firstsymbol; bp; bp = bp->next)
- {
- if (bp->class == nterm_sym)
- {
- 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 == token_sym */
- {
- bp->value = tokno++;
- }
-
- if (bp->class == token_sym)
- {
- 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;
-
- }
-
- if (translations)
- {
- int j;
-
- token_translations = XCALLOC (short, max_user_token_number + 1);
-
- /* 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;
-
- for (bp = firstsymbol; bp; bp = bp->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;
- }
- }
-
- error_token_number = errtoken->value;
-
- if (!no_parser_flag)
- output_token_defines (&table_obstack);
-
- if (startval->class == unknown_sym)
- fatal (_("the start symbol %s is undefined"), startval->tag);
- else if (startval->class == token_sym)
- fatal (_("the start symbol %s is a token"), startval->tag);
-
- start_symbol = startval->value;
-
- if (defines_flag)
- {
- output_token_defines (&defines_obstack);
-
- if (!pure_parser)
- {
- if (spec_name_prefix)
- obstack_fgrow1 (&defines_obstack, "\nextern YYSTYPE %slval;\n",
- spec_name_prefix);
- else
- obstack_grow_string (&defines_obstack,
- "\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] != '@')
- obstack_fgrow2 (&defines_obstack,
- "#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
- }
+ if (current_rule->action)
+ grammar_midrule_action ();
+ current_rule->action = action;
+ current_rule->action_location = loc;
}
-
+\f
/*---------------------------------------------------------------.
| Convert the rules into the representation using RRHS, RLHS and |
-| RITEMS. |
+| RITEM. |
`---------------------------------------------------------------*/
static void
packgram (void)
{
- int itemno;
- int ruleno;
- symbol_list *p;
+ unsigned int itemno = 0;
+ rule_number ruleno = 0;
+ symbol_list *p = grammar;
- bucket *ruleprec;
+ ritem = xnmalloc (nritems + 1, sizeof *ritem);
- ritem = XCALLOC (short, nitems + 1);
- rlhs = XCALLOC (short, nrules) - 1;
- rrhs = XCALLOC (short, nrules) - 1;
- rprec = XCALLOC (short, nrules) - 1;
- rprecsym = XCALLOC (short, nrules) - 1;
- rassoc = XCALLOC (short, nrules) - 1;
+ /* This sentinel is used by build_relations in gram.c. */
+ *ritem++ = 0;
- itemno = 0;
- ruleno = 1;
+ rules = xnmalloc (nrules, sizeof *rules);
- p = grammar;
while (p)
{
- rlhs[ruleno] = p->sym->value;
- rrhs[ruleno] = itemno;
- ruleprec = p->ruleprec;
+ symbol *ruleprec = p->ruleprec;
+ rules[ruleno].user_number = ruleno;
+ rules[ruleno].number = ruleno;
+ rules[ruleno].lhs = p->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;
+ rules[ruleno].action_location = p->action_location;
p = p->next;
while (p && p->sym)
{
- ritem[itemno++] = p->sym->value;
+ /* item_number = symbol_number.
+ But the former needs to contain more: negative rule numbers. */
+ ritem[itemno++] = symbol_number_as_item_number (p->sym->number);
/* A rule gets by default the precedence and associativity
of the last token in it. */
- if (p->sym->class == token_sym)
- {
- rprec[ruleno] = p->sym->prec;
- rassoc[ruleno] = p->sym->assoc;
- }
+ if (p->sym->class == token_sym && default_prec)
+ rules[ruleno].prec = p->sym;
if (p)
p = p->next;
}
the specified symbol's precedence replaces the default. */
if (ruleprec)
{
- rprec[ruleno] = ruleprec->prec;
- rassoc[ruleno] = ruleprec->assoc;
- rprecsym[ruleno] = ruleprec->value;
+ rules[ruleno].precsym = ruleprec;
+ rules[ruleno].prec = ruleprec;
}
-
- ritem[itemno++] = -ruleno;
- ruleno++;
+ ritem[itemno++] = rule_number_as_item_number (ruleno);
+ ++ruleno;
if (p)
p = p->next;
}
- ritem[itemno] = 0;
+ assert (itemno == nritems);
+
+ 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 guards are copied into the FGUARD file |
-| and all actions into ACTION_OBSTACK, 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. |
-`-------------------------------------------------------------------*/
+/*------------------------------------------------------------------.
+| 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. |
+`------------------------------------------------------------------*/
void
reader (void)
{
- start_flag = 0;
- startval = NULL; /* start symbol not specified yet. */
+ /* Initialize the symbol table. */
+ symbols_new ();
-#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;
+ /* Construct the accept symbol. */
+ accept = symbol_get ("$accept", empty_location);
+ accept->class = nterm_sym;
+ accept->number = nvars++;
- nsyms = 1;
- nvars = 0;
- nrules = 0;
- nitems = 0;
- rline_allocated = 10;
- rline = XCALLOC (short, rline_allocated);
+ /* Construct the error token */
+ errtoken = symbol_get ("error", empty_location);
+ errtoken->class = token_sym;
+ errtoken->number = ntokens++;
- typed = 0;
- lastprec = 0;
+ /* Construct a token that represents all undefined literal tokens.
+ It is always token number 2. */
+ undeftoken = symbol_get ("$undefined", empty_location);
+ undeftoken->class = token_sym;
+ undeftoken->number = ntokens++;
- gensym_count = 0;
+ /* Initialize the obstacks. */
+ obstack_init (&pre_prologue_obstack);
+ obstack_init (&post_prologue_obstack);
- semantic_parser = 0;
- pure_parser = 0;
+ gram_in = xfopen (grammar_file, "r");
- grammar = NULL;
+ gram__flex_debug = trace_flag & trace_scan;
+ gram_debug = trace_flag & trace_parse;
+ scanner_initialize ();
+ gram_parse ();
- init_lex ();
- lineno = 1;
+ if (! complaint_issued)
+ check_and_convert_grammar ();
- /* Initialize the symbol table. */
- tabinit ();
- /* Construct the error token */
- errtoken = getsym ("error");
- errtoken->class = token_sym;
- errtoken->user_token_number = 256; /* Value specified by POSIX. */
- /* Construct a token that represents all undefined literal tokens.
- It is always token number 2. */
- undeftoken = getsym ("$undefined.");
- undeftoken->class = token_sym;
- undeftoken->user_token_number = 2;
-
- /* Read the declaration section. Copy %{ ... %} groups to
- TABLE_OBSTACK and FDEFINES file. Also notice any %token, %left,
- etc. found there. */
- obstack_1grow (&table_obstack, '\n');
- obstack_fgrow3 (&table_obstack, "\
-/* %s, made from %s\n\
- by GNU bison %s. */\n\
-\n",
- no_parser_flag ? "Bison-generated parse tables" : "A Bison parser",
- infile, VERSION);
-
- obstack_grow_string (&table_obstack,
- "#define YYBISON 1 /* Identify Bison output. */\n\n");
- 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 (defines_flag)
- reader_output_yylsp (&defines_obstack);
- /* Write closing delimiters for actions and guards. */
- output_trailers ();
- if (locations_flag)
- obstack_grow_string (&table_obstack, "#define YYLSP_NEEDED 1\n\n");
- /* 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 ();
+ xfclose (gram_in);
}
-/*------------------------------------------------------------------.
-| Define YYLTYPE. Cannot be in the skeleton since we might have to |
-| output it in the headers if --defines is used. |
-`------------------------------------------------------------------*/
+/*-------------------------------------------------------------.
+| Check the grammar that has just been read, and convert it to |
+| internal form. |
+`-------------------------------------------------------------*/
-void
-reader_output_yylsp (struct obstack *oout)
+static void
+check_and_convert_grammar (void)
{
- if (locations_flag)
- obstack_grow_string (oout, "\
-\n\
-#ifndef YYLTYPE\n\
-typedef struct yyltype\n\
-{\n\
- int first_line;\n\
- int first_column;\n\
-\n\
- int last_line;\n\
- int last_column;\n\
-} yyltype;\n\
-\n\
-# define YYLTYPE yyltype\n\
-#endif\n\
-\n");
+ /* Grammar has been read. Do some checking. */
+ if (nrules == 0)
+ fatal (_("no rules in the input grammar"));
+
+ /* Report any undefined symbols and consider them nonterminals. */
+ symbols_check_defined ();
+
+ /* If the user did not define her ENDTOKEN, do it now. */
+ if (!endtoken)
+ {
+ endtoken = symbol_get ("$end", empty_location);
+ endtoken->class = token_sym;
+ endtoken->number = 0;
+ /* Value specified by POSIX. */
+ endtoken->user_token_number = 0;
+ }
+
+ /* 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_new (accept, empty_location);
+ p->location = grammar->location;
+ p->next = symbol_list_new (startsymbol, empty_location);
+ p->next->next = symbol_list_new (endtoken, empty_location);
+ p->next->next->next = symbol_list_new (NULL, empty_location);
+ p->next->next->next->next = grammar;
+ nrules += 1;
+ nritems += 3;
+ grammar = p;
+ }
+
+ assert (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
+
+ /* Assign the symbols their symbol numbers. Write #defines for the
+ token symbols into FDEFINES if requested. */
+ symbols_pack ();
+
+ /* Convert the grammar into the format described in gram.h. */
+ packgram ();
+
+ /* The grammar as a symbol_list is no longer needed. */
+ LIST_FREE (symbol_list, grammar);
}
projects / bison.git / blobdiff