X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/ee000ba4fcd5b051bef4476341a7fdffbddf8ad3..41cce2f604996c7713d9025f8a719ea56d83783e:/src/reader.c?ds=inline

diff --git a/src/reader.c b/src/reader.c
index c4883825..928a5408 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -26,7 +26,7 @@
 #include "getargs.h"
 #include "files.h"
 #include "symtab.h"
-#include "options.h"
+#include "symlist.h"
 #include "gram.h"
 #include "complain.h"
 #include "output.h"
@@ -34,61 +34,13 @@
 #include "conflicts.h"
 #include "muscle_tab.h"
 
-int lineno;
-static symbol_list *grammar = NULL;
+static symbol_list_t *grammar = NULL;
 static int start_flag = 0;
+merger_list *merge_functions;
 
 /* Nonzero if %union has been seen.  */
 int typed = 0;
-
-static symbol_list *
-symbol_list_new (symbol_t *sym, location_t location)
-{
-  symbol_list *res = XMALLOC (symbol_list, 1);
-  res->next = NULL;
-  res->sym = sym;
-  res->location = location;
-  res->action = NULL;
-  res->ruleprec = NULL;
-  return res;
-}
-
 
-/*--------------------------------------------------------------.
-| Get the data type (alternative in the union) of the value for |
-| symbol N in rule RULE.                                        |
-`--------------------------------------------------------------*/
-
-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;
-    }
-
-  return rp->sym->type_name;
-}
-
-
 /*-----------------------.
 | Set the start symbol.  |
 `-----------------------*/
@@ -97,7 +49,7 @@ void
 grammar_start_symbol_set (symbol_t *s, location_t l)
 {
   if (start_flag)
-    complain (_("multiple %s declarations"), "%start");
+    complain_at (l, _("multiple %s declarations"), "%start");
   else
     {
       start_flag = 1;
@@ -153,29 +105,66 @@ epilogue_set (const char *epilogue, location_t location)
 
 
 
-/*-------------------------------------------------------------------.
-| Generate a dummy symbol, a nonterminal, whose name cannot conflict |
-| with the user's names.                                             |
+ /*-------------------------------------------------------------------.
+| Return the merger index for a merging function named NAME, whose   |
+| arguments have type TYPE.  Records the function, if new, in        |
+| merger_list.							     |
 `-------------------------------------------------------------------*/
 
-static symbol_t *
-gensym (location_t location)
+static int
+get_merge_function (const char* name, const char* type,
+		    location_t loc)
 {
-  /* Incremented for each generated symbol */
-  static int gensym_count = 0;
-  static char buf[256];
+  merger_list *syms;
+  merger_list head;
+  int n;
+
+  if (! glr_parser)
+    return 0;
 
-  symbol_t *sym;
+  if (type == NULL)
+    type = "";
 
-  sprintf (buf, "@%d", ++gensym_count);
-  sym = getsym (buf, location);
-  sym->class = nterm_sym;
-  sym->number = nvars++;
-  return sym;
+  head.next = merge_functions;
+  for (syms = &head, n = 1; syms->next != NULL; syms = syms->next, n += 1)
+    if (strcmp (name, syms->next->name) == 0)
+      break;
+  if (syms->next == NULL)
+    {
+      syms->next = XMALLOC (merger_list, 1);
+      syms->next->name = xstrdup (name);
+      syms->next->type = xstrdup (type);
+      syms->next->next = NULL;
+      merge_functions = head.next;
+    }
+  else if (strcmp (type, syms->next->type) != 0)
+    warn_at (loc, _("result type clash on merge function %s: `%s' vs. `%s'"),
+	     name, type, syms->next->type);
+  return n;
 }
+
+/*--------------------------------------.
+| Free all merge-function definitions.	|
+`--------------------------------------*/
+
+void
+free_merger_functions (void)
+{
+  merger_list *L0;
+  if (! glr_parser)
+    return;
+  L0 = merge_functions;
+  while (L0 != NULL)
+    {
+      merger_list *L1 = L0->next;
+      free (L0);
+      L0 = L1;
+    }
+}
+
 
 /*-------------------------------------------------------------------.
-| Parse the input grammar into a one symbol_list structure.  Each    |
+| Parse the input grammar into a one symbol_list_t 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  |
@@ -193,13 +182,13 @@ gensym (location_t location)
 `-------------------------------------------------------------------*/
 
 /* The (currently) last symbol of GRAMMAR. */
-symbol_list *grammar_end = NULL;
+symbol_list_t *grammar_end = NULL;
 
 /* Append S to the GRAMMAR. */
 void
 grammar_symbol_append (symbol_t *symbol, location_t location)
 {
-  symbol_list *p = symbol_list_new (symbol, location);
+  symbol_list_t *p = symbol_list_new (symbol, location);
 
   if (grammar_end)
     grammar_end->next = p;
@@ -212,8 +201,8 @@ grammar_symbol_append (symbol_t *symbol, location_t location)
 /* 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;
+symbol_list_t *current_rule = NULL;
+symbol_list_t *previous_rule_end = NULL;
 
 
 /*----------------------------------------------.
@@ -247,7 +236,7 @@ grammar_rule_begin (symbol_t *lhs, location_t location)
       ++nvars;
     }
   else if (lhs->class == token_sym)
-    complain (_("rule given for %s, which is a token"), lhs->tag);
+    complain_at (location, _("rule given for %s, which is a token"), lhs->tag);
 }
 
 /* Check that the last rule (CURRENT_RULE) is properly defined.  For
@@ -257,29 +246,32 @@ static void
 grammar_current_rule_check (void)
 {
   symbol_t *lhs = current_rule->sym;
+  char const *lhs_type = lhs->type_name;
   symbol_t *first_rhs = current_rule->next->sym;
 
   /* If there is an action, then there is nothing we can do: the user
-     is allowed to shoot in her foot.  */
+     is allowed to shoot herself in the foot.  */
   if (current_rule->action)
     return;
 
-  /* If $$ is being set in default way, report if any type mismatch.
-     */
+  /* Don't worry about the default action if $$ 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 *lhs_type = lhs->type_name       ? lhs->type_name       : "";
       const char *rhs_type = first_rhs->type_name ? first_rhs->type_name : "";
       if (strcmp (lhs_type, rhs_type))
-	complain (_("type clash (`%s' `%s') on default action"),
-		  lhs_type, rhs_type);
+	complain_at (current_rule->location,
+		     _("type clash (`%s' `%s') on default action"),
+		     lhs_type, rhs_type);
     }
   /* Warn if there is no default for $$ but we need one.  */
   else
-    {
-      if (lhs->type_name)
-	complain (_("empty rule for typed nonterminal, and no action"));
-    }
+    complain_at (current_rule->location,
+		 _("empty rule for typed nonterminal, and no action"));
 }
 
 
@@ -314,8 +306,8 @@ grammar_midrule_action (void)
   /* Make a DUMMY nonterminal, whose location is that of the midrule
      action.  Create the MIDRULE.  */
   location_t dummy_location = current_rule->action_location;
-  symbol_t *dummy = gensym (dummy_location);
-  symbol_list *midrule = symbol_list_new (dummy, dummy_location);
+  symbol_t *dummy = dummy_symbol_get (dummy_location);
+  symbol_list_t *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.  */
@@ -346,13 +338,42 @@ grammar_midrule_action (void)
 /* Set the precedence symbol of the current rule to PRECSYM. */
 
 void
-grammar_current_rule_prec_set (symbol_t *precsym)
+grammar_current_rule_prec_set (symbol_t *precsym, location_t location)
 {
   if (current_rule->ruleprec)
-    complain (_("two @prec's in a row"));
+    complain_at (location, _("only one %s allowed per rule"), "%prec");
   current_rule->ruleprec = precsym;
 }
 
+/* Attach dynamic precedence DPREC to the current rule. */
+
+void
+grammar_current_rule_dprec_set (int dprec, location_t location)
+{
+  if (! glr_parser)
+    warn_at (location, _("%s affects only GLR parsers"), "%dprec");
+  if (dprec <= 0)
+    complain_at (location,
+		 _("%s must be followed by positive number"), "%dprec");
+  else if (current_rule->dprec != 0)
+    complain_at (location, _("only one %s allowed per rule"), "%dprec");
+  current_rule->dprec = dprec;
+}
+
+/* Attach a merge function NAME with argument type TYPE to current
+   rule. */
+
+void
+grammar_current_rule_merge_set (const char* name, location_t location)
+{
+  if (! glr_parser)
+    warn_at (location, _("%s affects only GLR parsers"), "%merge");
+  if (current_rule->merger != 0)
+    complain_at (location, _("only one %s allowed per rule"), "%merge");
+  current_rule->merger =
+    get_merge_function (name, current_rule->sym->type_name, location);
+}
+
 /* Attach a SYMBOL to the current rule.  If needed, move the previous
    action as a mid-rule action.  */
 
@@ -365,7 +386,6 @@ grammar_current_rule_symbol_append (symbol_t *symbol, location_t location)
   grammar_symbol_append (symbol, location);
 }
 
-
 /* Attach an ACTION to the current rule.  If needed, move the previous
    action as a mid-rule action.  */
 
@@ -387,17 +407,13 @@ grammar_current_rule_action_append (const char *action, location_t location)
 static void
 packgram (void)
 {
-  unsigned int itemno;
-  int ruleno;
-  symbol_list *p;
+  unsigned int itemno = 0;
+  rule_number_t ruleno = 0;
+  symbol_list_t *p = grammar;
 
   ritem = XCALLOC (item_number_t, nritems);
-  rules = XCALLOC (rule_t, nrules) - 1;
-
-  itemno = 0;
-  ruleno = 1;
+  rules = XCALLOC (rule_t, nrules);
 
-  p = grammar;
   while (p)
     {
       symbol_t *ruleprec = p->ruleprec;
@@ -406,9 +422,11 @@ packgram (void)
       rules[ruleno].lhs = p->sym;
       rules[ruleno].rhs = ritem + itemno;
       rules[ruleno].location = p->location;
-      rules[ruleno].useful = TRUE;
+      rules[ruleno].useful = true;
       rules[ruleno].action = p->action;
       rules[ruleno].action_location = p->action_location;
+      rules[ruleno].dprec = p->dprec;
+      rules[ruleno].merger = p->merger;
 
       p = p->next;
       while (p && p->sym)
@@ -431,7 +449,7 @@ packgram (void)
 	  rules[ruleno].precsym = ruleprec;
 	  rules[ruleno].prec = ruleprec;
 	}
-      ritem[itemno++] = -ruleno;
+      ritem[itemno++] = rule_number_as_item_number (ruleno);
       ++ruleno;
 
       if (p)
@@ -440,7 +458,7 @@ packgram (void)
 
   assert (itemno == nritems);
 
-  if (trace_flag)
+  if (trace_flag & trace_sets)
     ritem_print (stderr);
 }
 
@@ -455,24 +473,23 @@ void
 reader (void)
 {
   gram_control_t gram_control;
-  lineno = 1;
 
   /* Initialize the symbol table.  */
   symbols_new ();
 
-  /* Construct the axiom symbol. */
-  axiom = getsym ("$axiom", empty_location);
-  axiom->class = nterm_sym;
-  axiom->number = nvars++;
+  /* Construct the accept symbol. */
+  accept = symbol_get ("$accept", empty_location);
+  accept->class = nterm_sym;
+  accept->number = nvars++;
 
   /* Construct the error token */
-  errtoken = getsym ("error", empty_location);
+  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 ("$undefined.", empty_location);
+  undeftoken = symbol_get ("$undefined", empty_location);
   undeftoken->class = token_sym;
   undeftoken->number = ntokens++;
 
@@ -483,11 +500,16 @@ reader (void)
   finput = xfopen (infile, "r");
   gram_in = finput;
 
-  gram_debug = !!getenv ("parse");
-  gram__flex_debug = !!getenv ("scan");
+  gram__flex_debug = trace_flag & trace_scan;
+  gram_debug = trace_flag & trace_parse;
   scanner_initialize ();
   gram_parse (&gram_control);
 
+  /* If something went wrong during the parsing, don't try to
+     continue.  */
+  if (complaint_issued)
+    exit (EXIT_FAILURE);
+
   /* Grammar has been read.  Do some checking */
   if (nrules == 0)
     fatal (_("no rules in the input grammar"));
@@ -495,25 +517,25 @@ reader (void)
   /* Report any undefined symbols and consider them nonterminals.  */
   symbols_check_defined ();
 
-  /* If the user did not define her EOFTOKEN, do it now. */
-  if (!eoftoken)
+  /* If the user did not define her ENDTOKEN, do it now. */
+  if (!endtoken)
     {
-      eoftoken = getsym ("$", empty_location);
-      eoftoken->class = token_sym;
-      eoftoken->number = 0;
+      endtoken = symbol_get ("$end", empty_location);
+      endtoken->class = token_sym;
+      endtoken->number = 0;
       /* Value specified by POSIX.  */
-      eoftoken->user_token_number = 0;
+      endtoken->user_token_number = 0;
     }
 
   /* Insert the initial rule, which line is that of the first rule
      (not that of the start symbol):
 
-     axiom: %start EOF.  */
+     accept: %start EOF.  */
   {
-    symbol_list *p = symbol_list_new (axiom, empty_location);
+    symbol_list_t *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 (eoftoken, 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;
@@ -521,9 +543,9 @@ reader (void)
     grammar = p;
   }
 
-  if (nsyms > SHRT_MAX)
+  if (SYMBOL_NUMBER_MAX < nsyms)
     fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
-          SHRT_MAX);
+	   SYMBOL_NUMBER_MAX);
 
   assert (nsyms == ntokens + nvars);
 
@@ -536,6 +558,6 @@ reader (void)
   /* 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);
+  /* The grammar as a symbol_list_t is no longer needed. */
+  LIST_FREE (symbol_list_t, grammar);
 }