-/* Input parser for bison
- Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002
+/* Input parser for Bison
+
+ Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003
Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
-
#include "system.h"
-#include "quotearg.h"
-#include "quote.h"
-#include "getargs.h"
+
+#include <quotearg.h>
+
+#include "complain.h"
+#include "conflicts.h"
#include "files.h"
-#include "symtab.h"
-#include "options.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"
-#include "muscle_tab.h"
-
-typedef struct symbol_list
-{
- struct symbol_list *next;
- symbol_t *sym;
- int line;
-
- /* The action is attached to the LHS of a rule. */
- const char *action;
- int action_line;
-
- symbol_t *ruleprec;
-} symbol_list;
+#include "symlist.h"
+#include "symtab.h"
-int lineno;
static symbol_list *grammar = NULL;
-static int start_flag = 0;
+static bool start_flag = false;
+merger_list *merge_functions;
-/* Nonzero if %union has been seen. */
-static int typed = 0;
+/* Has %union been seen? */
+bool typed = false;
-/* Incremented for each %left, %right or %nonassoc seen */
-static int lastprec = 0;
-
-static symbol_list *
-symbol_list_new (symbol_t *sym)
-{
- symbol_list *res = XMALLOC (symbol_list, 1);
- res->next = NULL;
- res->sym = sym;
- res->line = lineno;
- res->action = NULL;
- res->action_line = 0;
- res->ruleprec = NULL;
- return res;
-}
-
-/*===================\
-| 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);
-}
-
-
-/*---------------------------------------------------------.
-| 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;
-}
+/* Should rules have a default precedence? */
+bool default_prec = true;
\f
-/*--------------------------------------------------------------.
-| Get the data type (alternative in the union) of the value for |
-| symbol N in rule RULE. |
-`--------------------------------------------------------------*/
+/*-----------------------.
+| Set the start symbol. |
+`-----------------------*/
-static char *
-get_type_name (int n, symbol_list *rule)
+void
+grammar_start_symbol_set (symbol *sym, location loc)
{
- int i;
- symbol_list *rp;
-
- if (n < 0)
- {
- complain (_("invalid $ value"));
- return NULL;
- }
-
- rp = rule;
- i = 0;
-
- while (i < n)
+ if (start_flag)
+ complain_at (loc, _("multiple %s declarations"), "%start");
+ else
{
- 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
-/*------------------------------------------------------------------.
-| Copy the character C to OOUT, and insert quadigraphs when needed. |
-`------------------------------------------------------------------*/
-
-static inline void
-copy_character (struct obstack *oout, int c)
-{
- switch (c)
- {
- case '[':
- obstack_sgrow (oout, "@<:@");
- break;
- case ']':
- obstack_sgrow (oout, "@:>@");
- break;
-
- default:
- obstack_1grow (oout, c);
- }
-}
-/*------------------------------------------------------------.
-| Dump the string from FIN to OOUT if non null. MATCH is the |
-| delimiter of the string (either ' or "). |
-`------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| There are two prologues: one before %union, one after. Augment |
+| the current one. |
+`----------------------------------------------------------------*/
-static inline void
-copy_string2 (FILE *fin, struct obstack *oout, int match, int store)
+void
+prologue_augment (const char *prologue, location loc)
{
- int c;
-
- if (store)
- 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;
- }
-
- copy_character (oout, c);
-
- if (c == '\\')
- {
- c = getc (fin);
- if (c == EOF)
- fatal (_("unterminated string at end of file"));
- copy_character (oout, c);
-
- if (c == '\n')
- ++lineno;
- }
-
- c = getc (fin);
- }
-
- if (store)
- obstack_1grow (oout, c);
+ 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);
}
-/* FIXME. */
-
-static inline void
-copy_string (FILE *fin, struct obstack *oout, int match)
-{
- copy_string2 (fin, oout, match, 1);
-}
+\f
-/* FIXME. */
+/*-------------------------------------------------------------------.
+| 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_identifier (FILE *fin, struct obstack *oout)
+static int
+get_merge_function (uniqstr name, uniqstr type, location loc)
{
- int c;
-
- while (isalnum (c = getc (fin)) || c == '_')
- obstack_1grow (oout, c);
-
- ungetc (c, fin);
-}
+ merger_list *syms;
+ merger_list head;
+ int n;
+ if (! glr_parser)
+ return 0;
-/*------------------------------------------------------------------.
-| Dump the wannabee comment from IN to OOUT. In fact we just saw a |
-| `/', which might or might not be a comment. In any case, copy |
-| what we saw. |
-`------------------------------------------------------------------*/
-
-static inline void
-copy_comment (FILE *fin, struct obstack *oout)
-{
- int cplus_comment;
- int ended;
- int c;
-
- /* We read a `/', output it. */
- obstack_1grow (oout, '/');
+ if (type == NULL)
+ type = uniqstr_new ("");
- switch ((c = getc (fin)))
- {
- case '/':
- cplus_comment = 1;
- break;
- case '*':
- cplus_comment = 0;
+ head.next = merge_functions;
+ for (syms = &head, n = 1; syms->next != NULL; syms = syms->next, n += 1)
+ if (UNIQSTR_EQ (name, syms->next->name))
break;
- default:
- ungetc (c, fin);
- return;
- }
-
- obstack_1grow (oout, c);
- c = getc (fin);
-
- ended = 0;
- while (!ended)
- {
- if (!cplus_comment && c == '*')
- {
- while (c == '*')
- {
- obstack_1grow (oout, c);
- c = getc (fin);
- }
-
- if (c == '/')
- {
- obstack_1grow (oout, c);
- ended = 1;
- }
- }
- else if (c == '\n')
- {
- ++lineno;
- obstack_1grow (oout, c);
- if (cplus_comment)
- ended = 1;
- else
- c = getc (fin);
- }
- else if (c == EOF)
- fatal (_("unterminated comment"));
- else
- {
- copy_character (oout, c);
- c = getc (fin);
- }
- }
+ if (syms->next == NULL)
+ {
+ MALLOC (syms->next, 1);
+ 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 location (i.e., a `@'). Output to OOUT a |
-| reference to this location. RULE_LENGTH is the number of values in |
-| the current rule so far, which says where to find `$0' with |
-| respect to the top of the stack. |
-`-------------------------------------------------------------------*/
-
-static inline void
-copy_at (FILE *fin, struct obstack *oout, int rule_length)
+void
+free_merger_functions (void)
{
- int c = getc (fin);
- locations_flag = 1;
-
- if (c == '$')
+ merger_list *L0;
+ if (! glr_parser)
+ return;
+ L0 = merge_functions;
+ while (L0 != NULL)
{
- obstack_sgrow (oout, "]b4_lhs_location[");
- }
- else if (isdigit (c) || c == '-')
- {
- int n;
-
- ungetc (c, fin);
- n = read_signed_integer (fin);
- if (n > rule_length)
- complain (_("invalid value: %s%d"), "@", n);
- else
- obstack_fgrow2 (oout, "]b4_rhs_location([%d], [%d])[",
- rule_length, n);
- }
- else
- {
- char buf[] = "@c";
- buf[1] = c;
- complain (_("%s is invalid"), quote (buf));
+ merger_list *L1 = L0->next;
+ free (L0);
+ L0 = L1;
}
}
-
-/*------------------------------------------------------------------.
-| FIN is pointing to a wannabee semantic value (i.e., a `$'). |
-| |
-| Possible inputs: $[<TYPENAME>]($|integer) |
-| |
-| Output to OOUT a reference to this semantic value. RULE_LENGTH is |
-| the number of values in the current rule so far, which says where |
-| to find `$0' with respect to the top of the stack. |
-`------------------------------------------------------------------*/
-
-static inline void
-copy_dollar (FILE *fin, struct obstack *oout,
- symbol_list *rule, int rule_length)
-{
- int c = getc (fin);
- const char *type_name = NULL;
-
- /* Get the type name if explicit. */
- if (c == '<')
- {
- read_type_name (fin);
- type_name = token_buffer;
- c = getc (fin);
- }
-
- if (c == '$')
- {
- if (!type_name)
- type_name = get_type_name (0, rule);
- if (!type_name && typed)
- complain (_("$$ of `%s' has no declared type"),
- rule->sym->tag);
- if (!type_name)
- type_name = "";
- obstack_fgrow1 (oout,
- "]b4_lhs_value([%s])[", type_name);
- }
- else if (isdigit (c) || c == '-')
- {
- int n;
- ungetc (c, fin);
- n = read_signed_integer (fin);
-
- if (n > rule_length)
- complain (_("invalid value: %s%d"), "$", n);
- else
- {
- if (!type_name && n > 0)
- type_name = get_type_name (n, rule);
- if (!type_name && typed)
- complain (_("$%d of `%s' has no declared type"),
- n, rule->sym->tag);
- if (!type_name)
- type_name = "";
- obstack_fgrow3 (oout, "]b4_rhs_value([%d], [%d], [%s])[",
- rule_length, n, type_name);
- }
- }
- else
- {
- char buf[] = "$c";
- buf[1] = c;
- complain (_("%s is invalid"), quote (buf));
- }
-}
\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. |
+| |
+| Bison used to allow some %directives in the rules sections, but |
+| this is no longer consider appropriate: (i) the documented grammar |
+| doesn't claim it, (ii), it would promote bad style, (iii), error |
+| recovery for %directives consists in skipping the junk until a `%' |
+| is seen and helrp synchronizing. This scheme is definitely wrong |
+| in the rules section. |
`-------------------------------------------------------------------*/
-static void
-copy_definition (struct obstack *oout)
-{
- int c;
- /* -1 while reading a character if prev char was %. */
- int after_percent;
-
- if (!no_lines_flag)
- {
- obstack_fgrow2 (oout, muscle_find ("linef"),
- lineno, quotearg_style (c_quoting_style,
- muscle_find ("filename")));
- }
-
- after_percent = 0;
-
- c = getc (finput);
-
- for (;;)
- {
- switch (c)
- {
- case '\n':
- obstack_1grow (oout, c);
- ++lineno;
- break;
-
- case '%':
- after_percent = -1;
- break;
-
- case '\'':
- case '"':
- copy_string (finput, oout, c);
- break;
-
- case '/':
- copy_comment (finput, oout);
- break;
+/* The (currently) last symbol of GRAMMAR. */
+symbol_list *grammar_end = NULL;
- case EOF:
- fatal ("%s", _("unterminated `%{' definition"));
-
- default:
- copy_character (oout, c);
- }
-
- c = getc (finput);
-
- if (after_percent)
- {
- if (c == '}')
- return;
- obstack_1grow (oout, '%');
- }
- 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. |
-`-------------------------------------------------------------------*/
-
-static void
-parse_token_decl (symbol_class what_is, symbol_class what_is_not)
+/* Append SYM to the grammar. */
+void
+grammar_symbol_append (symbol *sym, location loc)
{
- token_t token = tok_undef;
- char *typename = NULL;
-
- /* The symbol being defined. */
- symbol_t *symbol = NULL;
-
- /* After `%token' and `%nterm', any number of symbols maybe be
- defined. */
- for (;;)
- {
- int tmp_char = ungetc (skip_white_space (), finput);
+ symbol_list *p = symbol_list_new (sym, loc);
- /* `%' (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 == tok_comma)
- {
- symbol = NULL;
- continue;
- }
- if (token == tok_typename)
- {
- typename = xstrdup (token_buffer);
- symbol = NULL;
- }
- else if (token == tok_identifier && *symval->tag == '\"' && symbol)
- {
- symbol_make_alias (symbol, symval, typename);
- symbol = NULL;
- }
- else if (token == tok_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->number = nvars++;
- if (what_is == token_sym && symbol->number == NUMBER_UNDEFINED)
- symbol->number = ntokens++;
-
- 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 == tok_number)
- {
- symbol->user_token_number = numval;
- /* User defined EOF token? */
- if (numval == 0)
- {
- eoftoken = symbol;
- eoftoken->number = 0;
- /* It is always mapped to 0, so it was already counted in
- NTOKENS. */
- --ntokens;
- }
- }
- else
- {
- complain (_("`%s' is invalid in %s"),
- token_buffer,
- (what_is == token_sym) ? "%token" : "%nterm");
- skip_to_char ('%');
- }
- }
+ if (grammar_end)
+ grammar_end->next = p;
+ else
+ grammar = p;
+ grammar_end = p;
}
+/* 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;
+symbol_list *previous_rule_end = NULL;
-/*------------------------------.
-| Parse what comes after %start |
-`------------------------------*/
-
-static void
-parse_start_decl (void)
-{
- if (start_flag)
- complain (_("multiple %s declarations"), "%start");
- if (lex () != tok_identifier)
- complain (_("invalid %s declaration"), "%start");
- else
- {
- start_flag = 1;
- startsymbol = symval;
- }
-}
-/*-----------------------------------------------------------.
-| read in a %type declaration and record its information for |
-| get_type_name to access |
-`-----------------------------------------------------------*/
+/*----------------------------------------------.
+| Create a new rule for LHS in to the GRAMMAR. |
+`----------------------------------------------*/
-static void
-parse_type_decl (void)
+void
+grammar_rule_begin (symbol *lhs, location loc)
{
- char *name;
-
- if (lex () != tok_typename)
+ if (!start_flag)
{
- complain ("%s", _("%type declaration has no <typename>"));
- skip_to_char ('%');
- return;
+ startsymbol = lhs;
+ startsymbol_location = loc;
+ start_flag = true;
}
- name = xstrdup (token_buffer);
+ /* Start a new rule and record its lhs. */
+ ++nrules;
+ ++nritems;
- for (;;)
- {
- token_t t;
- int tmp_char = ungetc (skip_white_space (), finput);
-
- if (tmp_char == '%')
- return;
- if (tmp_char == EOF)
- fatal (_("Premature EOF after %s"), token_buffer);
+ previous_rule_end = grammar_end;
+ grammar_symbol_append (lhs, loc);
+ current_rule = grammar_end;
- t = lex ();
+ /* Mark the rule's lhs as a nonterminal if not already so. */
- switch (t)
- {
- case tok_comma:
- case tok_semicolon:
- break;
-
- case tok_identifier:
- symbol_type_set (symval, name);
- break;
-
- default:
- complain (_("invalid %%type declaration due to item: %s"),
- token_buffer);
- skip_to_char ('%');
- }
- }
-}
-
-
-
-/*----------------------------------------------------------------.
-| Read in a %left, %right or %nonassoc declaration and record its |
-| information. |
-`----------------------------------------------------------------*/
-
-static void
-parse_assoc_decl (associativity assoc)
-{
- char *name = NULL;
- int prev = 0;
-
- /* Assign a new precedence level, never 0. */
- ++lastprec;
-
- for (;;)
+ if (lhs->class == unknown_sym)
{
- token_t 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 tok_typename:
- name = xstrdup (token_buffer);
- break;
-
- case tok_comma:
- break;
-
- case tok_identifier:
- if (symval->class == nterm_sym)
- complain (_("symbol %s redefined"), symval->tag);
- if (symval->number == NUMBER_UNDEFINED)
- {
- symval->number = ntokens++;
- symval->class = token_sym;
- }
- symbol_precedence_set (symval, lastprec, assoc);
- if (name)
- symbol_type_set (symval, name);
- break;
-
- case tok_number:
- if (prev == tok_identifier)
- {
- symval->user_token_number = numval;
- }
- else
- {
- complain
- (_("invalid text (%s) - number should be after identifier"),
- token_buffer);
- skip_to_char ('%');
- }
- break;
-
- case tok_semicolon:
- return;
-
- default:
- complain (_("unexpected item: %s"), token_buffer);
- skip_to_char ('%');
- }
-
- prev = t;
+ 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);
}
-
-
-/*--------------------------------------------------------------.
-| Copy the union declaration into the stype muscle |
-| (and fdefines), where it is made into the definition of |
-| YYSTYPE, the type of elements of the parser value stack. |
-`--------------------------------------------------------------*/
+/* Check that the last rule (CURRENT_RULE) is properly defined. For
+ instance, there should be no type clash on the default action. */
static void
-parse_union_decl (void)
+grammar_current_rule_check (void)
{
- int c;
- int count = 0;
- bool done = FALSE;
- struct obstack union_obstack;
- if (typed)
- complain (_("multiple %s declarations"), "%union");
-
- typed = 1;
-
- MUSCLE_INSERT_INT ("stype_line", lineno);
- obstack_init (&union_obstack);
- obstack_sgrow (&union_obstack, "union");
-
- while (!done)
- {
- c = xgetc (finput);
-
- /* If C contains '/', it is output by copy_comment (). */
- if (c != '/')
- obstack_1grow (&union_obstack, c);
-
- switch (c)
- {
- case '\n':
- ++lineno;
- break;
-
- case '/':
- copy_comment (finput, &union_obstack);
- break;
-
- case '{':
- ++count;
- break;
-
- case '}':
- /* FIXME: Errr. How could this happen???. --akim */
- if (count == 0)
- complain (_("unmatched %s"), "`}'");
- count--;
- if (!count)
- done = TRUE;
- break;
- }
- }
-
- /* JF don't choke on trailing semi */
- c = skip_white_space ();
- if (c != ';')
- ungetc (c, finput);
- obstack_1grow (&union_obstack, 0);
- muscle_insert ("stype", obstack_finish (&union_obstack));
+ symbol *lhs = current_rule->sym;
+ char const *lhs_type = lhs->type_name;
+ symbol *first_rhs = current_rule->next->sym;
+
+ /* If there is an action, then there is nothing we can do: the user
+ is allowed to shoot herself in the foot. */
+ if (current_rule->action)
+ return;
+
+ /* Don't worry about the default action if $$ is untyped, since $$'s
+ value can't be used. */
+ if (! lhs_type)
+ return;
+
+ /* If $$ is being set in default way, report if any type mismatch. */
+ if (first_rhs)
+ {
+ const char *rhs_type = first_rhs->type_name ? first_rhs->type_name : "";
+ if (!UNIQSTR_EQ (lhs_type, rhs_type))
+ warn_at (current_rule->location,
+ _("type clash on default action: <%s> != <%s>"),
+ lhs_type, rhs_type);
+ }
+ /* Warn if there is no default for $$ but we need one. */
+ else
+ warn_at (current_rule->location,
+ _("empty rule for typed nonterminal, and no action"));
}
-/*-------------------------------------------------------.
-| Parse the declaration %expect N which says to expect N |
-| shift-reduce conflicts. |
-`-------------------------------------------------------*/
+/*-------------------------------------.
+| End the currently being grown rule. |
+`-------------------------------------*/
-static void
-parse_expect_decl (void)
+void
+grammar_rule_end (location loc)
{
- 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);
+ /* 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_current_rule_check ();
}
/*-------------------------------------------------------------------.
-| 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 |
-| USER_NUMBER_ALIAS 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 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
-parse_thong_decl (void)
-{
- token_t token;
- symbol_t *symbol;
- char *typename = 0;
- int usrtoknum = USER_NUMBER_UNDEFINED;
-
- token = lex (); /* fetch typename or first token */
- if (token == tok_typename)
- {
- typename = xstrdup (token_buffer);
- token = lex (); /* fetch first token */
- }
-
- /* process first token */
-
- if (token != tok_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 = USER_NUMBER_ALIAS;
- symbol = symval;
-
- token = lex (); /* get number or literal string */
-
- if (token == tok_number)
- {
- usrtoknum = numval;
- token = lex (); /* okay, did number, now get literal */
- }
-
- /* process literal string token */
-
- if (token != tok_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--;
-}
-
-
-static void
-parse_muscle_decl (void)
+void
+grammar_midrule_action (void)
{
- int ch = ungetc (skip_white_space (), finput);
- char *muscle_key;
- char *muscle_value;
+ /* 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 (previous_rule_end)
+ previous_rule_end->next = midrule;
+ else
+ grammar = midrule;
- /* Read key. */
- if (!isalpha (ch) && ch != '_')
- {
- complain (_("invalid %s declaration"), "%define");
- skip_to_char ('%');
- return;
- }
- copy_identifier (finput, &muscle_obstack);
- obstack_1grow (&muscle_obstack, 0);
- muscle_key = obstack_finish (&muscle_obstack);
+ /* End the dummy's rule. */
+ previous_rule_end = symbol_list_new (NULL, dummy_location);
+ previous_rule_end->next = current_rule;
- /* Read value. */
- ch = skip_white_space ();
- if (ch != '"')
- {
- ungetc (ch, finput);
- if (ch != EOF)
- {
- complain (_("invalid %s declaration"), "%define");
- skip_to_char ('%');
- return;
- }
- else
- fatal (_("Premature EOF after %s"), "\"");
- }
- copy_string2 (finput, &muscle_obstack, '"', 0);
- obstack_1grow (&muscle_obstack, 0);
- muscle_value = obstack_finish (&muscle_obstack);
+ midrule->next = previous_rule_end;
- /* Store the (key, value) pair in the environment. */
- muscle_insert (muscle_key, muscle_value);
+ /* Insert the dummy nonterminal replacing the midrule action into
+ the current rule. */
+ grammar_current_rule_symbol_append (dummy, dummy_location);
}
+/* Set the precedence symbol of the current rule to PRECSYM. */
-
-/*---------------------------------.
-| Parse a double quoted parameter. |
-`---------------------------------*/
-
-static const char *
-parse_dquoted_param (const char *from)
+void
+grammar_current_rule_prec_set (symbol *precsym, location loc)
{
- struct obstack param_obstack;
- const char *param = NULL;
- int c;
-
- obstack_init (¶m_obstack);
- c = skip_white_space ();
-
- if (c != '"')
- {
- complain (_("invalid %s declaration"), from);
- ungetc (c, finput);
- skip_to_char ('%');
- return NULL;
- }
-
- while ((c = literalchar ()) != '"')
- obstack_1grow (¶m_obstack, c);
-
- obstack_1grow (¶m_obstack, '\0');
- param = obstack_finish (¶m_obstack);
-
- if (c != '"' || strlen (param) == 0)
- {
- complain (_("invalid %s declaration"), from);
- if (c != '"')
- ungetc (c, finput);
- skip_to_char ('%');
- return NULL;
- }
-
- return param;
+ if (current_rule->ruleprec)
+ complain_at (loc, _("only one %s allowed per rule"), "%prec");
+ current_rule->ruleprec = precsym;
}
-/*----------------------------------.
-| Parse what comes after %skeleton. |
-`----------------------------------*/
+/* Attach dynamic precedence DPREC to the current rule. */
-static void
-parse_skel_decl (void)
+void
+grammar_current_rule_dprec_set (int dprec, location loc)
{
- skeleton = parse_dquoted_param ("%skeleton");
+ 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;
}
-/*----------------------------------------------------------------.
-| Read from finput until `%%' is seen. Discard the `%%'. Handle |
-| any `%' declarations, and copy the contents of any `%{ ... %}' |
-| groups to PRE_PROLOGUE_OBSTACK or POST_PROLOGUE_OBSTACK. |
-`----------------------------------------------------------------*/
-
-static void
-read_declarations (void)
-{
- for (;;)
- {
- int c = skip_white_space ();
+/* Attach a merge function NAME with argument type TYPE to current
+ rule. */
- if (c == '%')
- {
- token_t tok = parse_percent_token ();
-
- switch (tok)
- {
- case tok_two_percents:
- return;
-
- case tok_percent_left_curly:
- if (!typed)
- copy_definition (&pre_prologue_obstack);
- else
- copy_definition (&post_prologue_obstack);
- break;
-
- case tok_token:
- parse_token_decl (token_sym, nterm_sym);
- break;
-
- case tok_nterm:
- parse_token_decl (nterm_sym, token_sym);
- break;
-
- case tok_type:
- parse_type_decl ();
- break;
-
- case tok_start:
- parse_start_decl ();
- break;
-
- case tok_union:
- parse_union_decl ();
- break;
-
- case tok_expect:
- parse_expect_decl ();
- break;
-
- case tok_thong:
- parse_thong_decl ();
- break;
-
- case tok_left:
- parse_assoc_decl (left_assoc);
- break;
-
- case tok_right:
- parse_assoc_decl (right_assoc);
- break;
-
- case tok_nonassoc:
- parse_assoc_decl (non_assoc);
- break;
-
- case tok_define:
- parse_muscle_decl ();
- break;
-
- case tok_skel:
- parse_skel_decl ();
- break;
-
- case tok_noop:
- break;
-
- case tok_stropt:
- case tok_intopt:
- case tok_obsolete:
- assert (0);
- break;
-
- case tok_illegal:
- default:
- complain (_("unrecognized: %s"), token_buffer);
- skip_to_char ('%');
- }
- }
- else if (c == EOF)
- fatal (_("no input grammar"));
- else
- {
- char buf[] = "c";
- buf[0] = c;
- complain (_("unknown character: %s"), quote (buf));
- skip_to_char ('%');
- }
- }
-}
-\f
-/*------------------------------------------------------------------.
-| Assuming that a `{' has just been seen, copy everything up to the |
-| matching `}' into ACTION_OBSTACK. |
-| |
-| RULE_LENGTH 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. It is not the same as the rule->length in the case of mid |
-| rule actions. |
-| |
-| This routine is used for actions. |
-`------------------------------------------------------------------*/
-
-static void
-parse_action (symbol_list *rule, int rule_length)
+void
+grammar_current_rule_merge_set (uniqstr name, location loc)
{
- int count = 1;
- rule->action_line = lineno;
- while (count > 0)
- {
- int c;
- while ((c = getc (finput)) != '}')
- switch (c)
- {
- case '\n':
- copy_character (&action_obstack, c);
- ++lineno;
- break;
-
- case '{':
- copy_character (&action_obstack, c);
- ++count;
- break;
-
- case '\'':
- case '"':
- copy_string (finput, &action_obstack, c);
- break;
-
- case '/':
- copy_comment (finput, &action_obstack);
- break;
-
- case '$':
- copy_dollar (finput, &action_obstack, rule, rule_length);
- break;
-
- case '@':
- copy_at (finput, &action_obstack, rule_length);
- break;
-
- case EOF:
- fatal (_("unmatched %s"), "`{'");
-
- default:
- copy_character (&action_obstack, c);
- }
-
- /* Above loop exits when C is '}'. */
- if (--count)
- copy_character (&action_obstack, c);
- }
-
- obstack_1grow (&action_obstack, '\0');
- rule->action = obstack_finish (&action_obstack);
+ 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
-
-/*-------------------------------------------------------------------.
-| Generate a dummy symbol, a nonterminal, whose name cannot conflict |
-| with the user's names. |
-`-------------------------------------------------------------------*/
+/* Attach SYM to the current rule. If needed, move the previous
+ action as a mid-rule action. */
-static symbol_t *
-gensym (void)
+void
+grammar_current_rule_symbol_append (symbol *sym, location loc)
{
- /* Incremented for each generated symbol */
- static int gensym_count = 0;
- static char buf[256];
-
- symbol_t *sym;
-
- sprintf (buf, "@%d", ++gensym_count);
- token_buffer = buf;
- sym = getsym (token_buffer);
- sym->class = nterm_sym;
- sym->number = nvars++;
- return sym;
+ if (current_rule->action)
+ grammar_midrule_action ();
+ ++nritems;
+ grammar_symbol_append (sym, loc);
}
-\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. |
-| |
-| Bison used to allow some %directives in the rules sections, but |
-| this is no longer consider appropriate: (i) the documented grammar |
-| doesn't claim it, (ii), it would promote bad style, (iii), error |
-| recovery for %directives consists in skipping the junk until a `%' |
-| is seen and helrp synchronizing. This scheme is definitely wrong |
-| in the rules section. |
-`-------------------------------------------------------------------*/
-
-static void
-readgram (void)
-{
- token_t t;
- symbol_t *lhs = NULL;
- symbol_list *p = NULL;
- symbol_list *p1 = NULL;
-
- /* Points to first symbol_list of current rule. its symbol is the
- lhs of the rule. */
- symbol_list *crule = NULL;
- /* Points to the symbol_list preceding crule. */
- symbol_list *crule1 = NULL;
-
- t = lex ();
-
- while (t != tok_two_percents && t != tok_eof)
- if (t == tok_identifier || t == tok_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 */
- symbol_t *first_rhs = 0;
-
- if (t == tok_identifier)
- {
- lhs = symval;
-
- if (!start_flag)
- {
- startsymbol = lhs;
- start_flag = 1;
- }
-
- t = lex ();
- if (t != tok_colon)
- {
- complain (_("ill-formed rule: initial symbol not followed by colon"));
- unlex (t);
- }
- }
-
- if (nrules == 0 && t == tok_bar)
- {
- complain (_("grammar starts with vertical bar"));
- lhs = symval; /* BOGUS: use a random symval */
- }
- /* start a new rule and record its lhs. */
-
- ++nrules;
- ++nritems;
-
- p = symbol_list_new (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->number = 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 == tok_prec)
- {
- t = lex ();
- crule->ruleprec = symval;
- t = lex ();
- }
-
- if (!(t == tok_identifier || t == tok_left_curly))
- break;
-
- /* If next token is an identifier, see if a colon follows it.
- If one does, exit this rule now. */
- if (t == tok_identifier)
- {
- symbol_t *ssave;
- token_t t1;
-
- ssave = symval;
- t1 = lex ();
- unlex (t1);
- symval = ssave;
- if (t1 == tok_colon)
- {
- warn (_("previous rule lacks an ending `;'"));
- 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)
- {
- /* 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. */
- symbol_t *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;
- ++nritems;
- p = symbol_list_new (sdummy);
- /* Attach its lineno to that of the host rule. */
- p->line = crule->line;
- /* Move the action from the host rule to this one. */
- p->action = crule->action;
- p->action_line = crule->action_line;
- crule->action = NULL;
-
- if (crule1)
- crule1->next = p;
- else
- grammar = p;
- /* End of the rule. */
- crule1 = symbol_list_new (NULL);
- crule1->next = crule;
-
- p->next = crule1;
-
- /* Insert the dummy generated by that rule into this
- rule. */
- ++nritems;
- p = symbol_list_new (sdummy);
- p1->next = p;
- p1 = p;
-
- action_flag = 0;
- }
-
- if (t == tok_identifier)
- {
- ++nritems;
- p = symbol_list_new (symval);
- p1->next = p;
- p1 = p;
- }
- else /* handle an action. */
- {
- parse_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 = symbol_list_new (NULL);
- p1->next = p;
- p1 = p;
-
- if (t == tok_prec)
- {
- complain (_("two @prec's in a row"));
- t = lex ();
- crule->ruleprec = symval;
- t = lex ();
- }
-
- if (t == tok_left_curly)
- {
- /* This case never occurs -wjh */
- if (action_flag)
- complain (_("two actions at end of one rule"));
- parse_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 == tok_two_percents || t == tok_eof)
- warn (_("previous rule lacks an ending `;'"));
- if (t == tok_semicolon)
- t = lex ();
- }
- else
- {
- complain (_("invalid input: %s"), quote (token_buffer));
- t = lex ();
- }
-
- /* 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 ();
- /* Insert the initial rule, which line is that of the first rule
- (not that of the start symbol):
+/* Attach an ACTION to the current rule. If needed, move the previous
+ action as a mid-rule action. */
- axiom: %start EOF. */
- p = symbol_list_new (axiom);
- p->line = grammar->line;
- p->next = symbol_list_new (startsymbol);
- p->next->next = symbol_list_new (eoftoken);
- p->next->next->next = symbol_list_new (NULL);
- p->next->next->next->next = grammar;
- nrules += 1;
- nritems += 3;
- grammar = p;
-
- if (nsyms > SHRT_MAX)
- fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
- SHRT_MAX);
-
- assert (nsyms == ntokens + nvars);
-}
-
-/* At the end of the grammar file, some C source code must
- be stored. It is going to be associated to the epilogue
- directive. */
-static void
-read_additionnal_code (void)
+void
+grammar_current_rule_action_append (const char *action, location loc)
{
- int c;
- struct obstack el_obstack;
-
- obstack_init (&el_obstack);
-
- if (!no_lines_flag)
- {
- obstack_fgrow2 (&el_obstack, muscle_find ("linef"),
- lineno, quotearg_style (c_quoting_style,
- muscle_find ("filename")));
- }
-
- while ((c = getc (finput)) != EOF)
- copy_character (&el_obstack, c);
-
- obstack_1grow (&el_obstack, 0);
- muscle_insert ("epilogue", obstack_finish (&el_obstack));
+ if (current_rule->action)
+ grammar_midrule_action ();
+ current_rule->action = action;
+ current_rule->action_location = loc;
}
\f
static void
packgram (void)
{
- unsigned int itemno;
- int ruleno;
- symbol_list *p;
-
- ritem = XCALLOC (item_number_t, nritems);
- rules = XCALLOC (rule_t, nrules) - 1;
+ unsigned int itemno = 0;
+ rule_number ruleno = 0;
+ symbol_list *p = grammar;
- itemno = 0;
- ruleno = 1;
+ CALLOC (ritem, nritems);
+ CALLOC (rules, nrules);
- p = grammar;
while (p)
{
- symbol_t *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].line = p->line;
- rules[ruleno].useful = TRUE;
+ rules[ruleno].location = p->location;
+ rules[ruleno].useful = true;
rules[ruleno].action = p->action;
- rules[ruleno].action_line = p->action_line;
+ rules[ruleno].action_location = p->action_location;
+ rules[ruleno].dprec = p->dprec;
+ rules[ruleno].merger = p->merger;
p = p->next;
while (p && p->sym)
{
- /* item_number_t = symbol_number_t.
+ /* 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)
+ if (p->sym->class == token_sym && default_prec)
rules[ruleno].prec = p->sym;
if (p)
p = p->next;
rules[ruleno].precsym = ruleprec;
rules[ruleno].prec = ruleprec;
}
- ritem[itemno++] = -ruleno;
+ ritem[itemno++] = rule_number_as_item_number (ruleno);
++ruleno;
if (p)
p = p->next;
}
- assert (itemno == nritems);
+ if (itemno != nritems)
+ abort ();
- if (trace_flag)
+ if (trace_flag & trace_sets)
ritem_print (stderr);
}
\f
void
reader (void)
{
- lex_init ();
- lineno = 1;
-
- /* Initialize the muscle obstack. */
- obstack_init (&muscle_obstack);
-
/* Initialize the symbol table. */
symbols_new ();
- /* Construct the axiom symbol. */
- axiom = getsym ("$axiom");
- axiom->class = nterm_sym;
- axiom->number = nvars++;
+ /* Construct the accept symbol. */
+ accept = symbol_get ("$accept", empty_location);
+ accept->class = nterm_sym;
+ accept->number = nvars++;
/* Construct the error token */
- errtoken = getsym ("error");
+ errtoken = symbol_get ("error", empty_location);
errtoken->class = token_sym;
errtoken->number = ntokens++;
/* Construct a token that represents all undefined literal tokens.
It is always token number 2. */
- undeftoken = getsym ("$undefined.");
+ undeftoken = symbol_get ("$undefined", empty_location);
undeftoken->class = token_sym;
undeftoken->number = ntokens++;
/* Initialize the obstacks. */
- obstack_init (&action_obstack);
- obstack_init (&output_obstack);
obstack_init (&pre_prologue_obstack);
obstack_init (&post_prologue_obstack);
- finput = xfopen (infile, "r");
+ finput = xfopen (grammar_file, "r");
+ gram_in = finput;
+
+ gram__flex_debug = trace_flag & trace_scan;
+ gram_debug = trace_flag & trace_parse;
+ scanner_initialize ();
+ gram_parse ();
+
+ /* If something went wrong during the parsing, don't try to
+ continue. */
+ if (complaint_issued)
+ return;
- /* Read the declaration section. Copy %{ ... %} groups to
- TABLE_OBSTACK and FDEFINES file. Also notice any %token, %left,
- etc. found there. */
- read_declarations ();
+ /* Grammar has been read. Do some checking */
+ if (nrules == 0)
+ fatal (_("no rules in the input grammar"));
- /* If the user did not define her EOFTOKEN, do it now. */
- if (!eoftoken)
+ /* Report any undefined symbols and consider them nonterminals. */
+ symbols_check_defined ();
+
+ /* If the user did not define her ENDTOKEN, do it now. */
+ if (!endtoken)
{
- eoftoken = getsym ("$");
- eoftoken->class = token_sym;
- eoftoken->number = 0;
+ endtoken = symbol_get ("$end", empty_location);
+ endtoken->class = token_sym;
+ endtoken->number = 0;
/* Value specified by POSIX. */
- eoftoken->user_token_number = 0;
+ endtoken->user_token_number = 0;
}
- /* Read in the grammar, build grammar in list form. Write out
- actions. */
- readgram ();
- /* Some C code is given at the end of the grammar file. */
- read_additionnal_code ();
+ /* Insert the initial rule, which 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;
+ }
+
+ if (! (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars))
+ abort ();
- lex_free ();
xfclose (finput);
/* Assign the symbols their symbol numbers. Write #defines for the
projects / bison.git / blobdiff