X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/1d6412adebec68e299086248a6a92a4191bbbec9..d1a1114f7f257f89887ea5825ba0d896dfaa747b:/src/reader.c

diff --git a/src/reader.c b/src/reader.c
index 822b9fe4..d7527158 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"
@@ -34,75 +34,27 @@
 #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)
-{
-  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;
-}
-
 
-/*--------------------------------------------------------------.
-| 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.  |
 `-----------------------*/
 
 void
-grammar_start_symbol_set (symbol_t *s)
+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;
       startsymbol = s;
+      startsymbol_location = l;
     }
 }
 
@@ -113,7 +65,7 @@ grammar_start_symbol_set (symbol_t *s)
 `----------------------------------------------------------------*/
 
 void
-prologue_augment (const char *prologue, int location)
+prologue_augment (const char *prologue, location_t location)
 {
   struct obstack *oout =
     !typed ? &pre_prologue_obstack : &post_prologue_obstack;
@@ -121,8 +73,9 @@ prologue_augment (const char *prologue, int location)
   if (!no_lines_flag)
     {
       obstack_fgrow2 (oout, muscle_find ("linef"),
-		      location, quotearg_style (c_quoting_style,
-						muscle_find ("filename")));
+		      location.first_line,
+		      quotearg_style (c_quoting_style,
+				      muscle_find ("filename")));
     }
   obstack_sgrow (oout, prologue);
 }
@@ -135,48 +88,83 @@ prologue_augment (const char *prologue, int location)
 `----------------------*/
 
 void
-epilogue_set (const char *epilogue, int location)
+epilogue_set (const char *epilogue, location_t location)
 {
-  struct obstack el_obstack;
-  obstack_init (&el_obstack);
-
   if (!no_lines_flag)
     {
-      obstack_fgrow2 (&el_obstack, muscle_find ("linef"),
-		      location, quotearg_style (c_quoting_style,
-						muscle_find ("filename")));
+      obstack_fgrow2 (&muscle_obstack, muscle_find ("linef"),
+		      location.first_line,
+		      quotearg_style (c_quoting_style,
+				      muscle_find ("filename")));
     }
-  obstack_sgrow (&el_obstack, epilogue);
-  obstack_1grow (&el_obstack, 0);
-  muscle_insert ("epilogue", obstack_finish (&el_obstack));
+  obstack_sgrow (&muscle_obstack, epilogue);
+  obstack_1grow (&muscle_obstack, 0);
+  muscle_insert ("epilogue", obstack_finish (&muscle_obstack));
 }
 
 
 
 
-/*-------------------------------------------------------------------.
-| 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 (void)
+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;
+
+  if (type == NULL)
+    type = "";
+
+  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;
+}
 
-  symbol_t *sym;
+/*--------------------------------------.
+| Free all merge-function definitions.	|
+`--------------------------------------*/
 
-  sprintf (buf, "@%d", ++gensym_count);
-  sym = getsym (buf);
-  sym->class = nterm_sym;
-  sym->number = nvars++;
-  return sym;
+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  |
@@ -194,13 +182,13 @@ gensym (void)
 `-------------------------------------------------------------------*/
 
 /* 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 *s)
+grammar_symbol_append (symbol_t *symbol, location_t location)
 {
-  symbol_list *p = symbol_list_new (s);
+  symbol_list_t *p = symbol_list_new (symbol, location);
 
   if (grammar_end)
     grammar_end->next = p;
@@ -210,20 +198,24 @@ grammar_symbol_append (symbol_t *s)
   grammar_end = p;
 }
 
-/* The rule currently being defined, and the previous rule.  Point to
-   the first symbol of each list: their lhs.  */
-symbol_list *current_rule = NULL;
-symbol_list *previous_rule = NULL;
+/* 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_t *current_rule = NULL;
+symbol_list_t *previous_rule_end = NULL;
 
 
-/* Create a new rule for LHS in to the GRAMMAR. */
+/*----------------------------------------------.
+| Create a new rule for LHS in to the GRAMMAR.  |
+`----------------------------------------------*/
 
 void
-grammar_rule_begin (symbol_t *lhs)
+grammar_rule_begin (symbol_t *lhs, location_t location)
 {
   if (!start_flag)
     {
       startsymbol = lhs;
+      startsymbol_location = location;
       start_flag = 1;
     }
 
@@ -231,8 +223,8 @@ grammar_rule_begin (symbol_t *lhs)
   ++nrules;
   ++nritems;
 
-  previous_rule = grammar_end;
-  grammar_symbol_append (lhs);
+  previous_rule_end = grammar_end;
+  grammar_symbol_append (lhs, location);
   current_rule = grammar_end;
 
   /* Mark the rule's lhs as a nonterminal if not already so.  */
@@ -244,7 +236,7 @@ grammar_rule_begin (symbol_t *lhs)
       ++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
@@ -268,33 +260,40 @@ grammar_current_rule_check (void)
       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"));
     }
 }
 
 
-/* End the currently being grown rule. */
+/*-------------------------------------.
+| End the currently being grown rule.  |
+`-------------------------------------*/
 
 void
-grammar_rule_end (void)
+grammar_rule_end (location_t location)
 {
   /* Put an empty link in the list to mark the end of this rule  */
-  grammar_symbol_append (NULL);
+  grammar_symbol_append (NULL, grammar_end->location);
+  current_rule->location = location;
   grammar_current_rule_check ();
 }
 
 
-/* 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.  */
+/*-------------------------------------------------------------------.
+| 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.                                                              |
+`-------------------------------------------------------------------*/
 
 void
 grammar_midrule_action (void)
@@ -303,70 +302,98 @@ grammar_midrule_action (void)
      give the new rule this number by inserting the new rule before
      it.  */
 
-  /* Make a dummy nonterminal, a gensym.  */
-  symbol_t *sdummy = gensym ();
-  symbol_list *midrule_action = symbol_list_new (sdummy);
+  /* 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 = 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.  */
   ++nrules;
   ++nritems;
-  /* Attach its lineno to that of the host rule.  */
-  midrule_action->line = current_rule->line;
-  /* Move the action from the host rule to this one.  */
-  midrule_action->action = current_rule->action;
-  midrule_action->action_line = current_rule->action_line;
+  /* 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)
-    previous_rule->next = midrule_action;
+  if (previous_rule_end)
+    previous_rule_end->next = midrule;
   else
-    grammar = midrule_action;
+    grammar = midrule;
 
-  /* End of the rule. */
-  previous_rule = symbol_list_new (NULL);
-  previous_rule->next = current_rule;
+  /* End the dummy's rule.  */
+  previous_rule_end = symbol_list_new (NULL, dummy_location);
+  previous_rule_end->next = current_rule;
 
-  midrule_action->next = previous_rule;
+  midrule->next = previous_rule_end;
 
-  /* Insert the dummy generated by that rule into this rule.  */
-  ++nritems;
-  grammar_symbol_append (sdummy);
+  /* 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. */
 
 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, _("two @prec's in a row"));
   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, _("%%dprec affects only GLR parsers"));
+  if (dprec <= 0)
+    complain_at (location, _("%%dprec must be followed by positive number"));
+  else if (current_rule->dprec != 0)
+    complain_at (location, _("only one %%dprec allowed per rule"));
+  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, _("%%merge affects only GLR parsers"));
+  if (current_rule->merger != 0)
+    complain_at (location, _("only one %%merge allowed per rule"));
+  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.  */
 
 void
-grammar_current_rule_symbol_append (symbol_t *symbol)
+grammar_current_rule_symbol_append (symbol_t *symbol, location_t location)
 {
   if (current_rule->action)
     grammar_midrule_action ();
   ++nritems;
-  grammar_symbol_append (symbol);
+  grammar_symbol_append (symbol, location);
 }
 
-
 /* Attach an ACTION to the current rule.  If needed, move the previous
    action as a mid-rule action.  */
 
 void
-grammar_current_rule_action_append (const char *action, int action_line)
+grammar_current_rule_action_append (const char *action, location_t location)
 {
   if (current_rule->action)
     grammar_midrule_action ();
   current_rule->action = action;
-  current_rule->action_line = action_line;
+  current_rule->action_location = location;
 }
 
 
@@ -378,17 +405,13 @@ grammar_current_rule_action_append (const char *action, int action_line)
 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;
+  rules = XCALLOC (rule_t, nrules);
 
-  itemno = 0;
-  ruleno = 1;
-
-  p = grammar;
   while (p)
     {
       symbol_t *ruleprec = p->ruleprec;
@@ -396,10 +419,12 @@ packgram (void)
       rules[ruleno].number = ruleno;
       rules[ruleno].lhs = p->sym;
       rules[ruleno].rhs = ritem + itemno;
-      rules[ruleno].line = p->line;
+      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)
@@ -422,7 +447,7 @@ packgram (void)
 	  rules[ruleno].precsym = ruleprec;
 	  rules[ruleno].prec = ruleprec;
 	}
-      ritem[itemno++] = -ruleno;
+      ritem[itemno++] = rule_number_as_item_number (ruleno);
       ++ruleno;
 
       if (p)
@@ -431,7 +456,7 @@ packgram (void)
 
   assert (itemno == nritems);
 
-  if (trace_flag)
+  if (trace_flag & trace_sets)
     ritem_print (stderr);
 }
 
@@ -446,33 +471,27 @@ void
 reader (void)
 {
   gram_control_t gram_control;
-  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);
 
@@ -484,6 +503,11 @@ reader (void)
   scanner_initialize ();
   gram_parse (&gram_control);
 
+  /* If something went wrong during the parsing, don't try to
+     continue.  */
+  if (complain_message_count)
+    exit (1);
+
   /* Grammar has been read.  Do some checking */
   if (nrules == 0)
     fatal (_("no rules in the input grammar"));
@@ -491,26 +515,26 @@ 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 ("$");
-      eoftoken->class = token_sym;
-      eoftoken->number = 0;
+      endtoken = symbol_get ("$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);
-    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);
+    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 (endtoken, empty_location);
+    p->next->next->next = symbol_list_new (NULL, empty_location);
     p->next->next->next->next = grammar;
     nrules += 1;
     nritems += 3;
@@ -532,6 +556,6 @@ 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);
 }