From e1094c4c09acaa9d942c8e8e271788a9b6ea11df Mon Sep 17 00:00:00 2001
From: Akim Demaille <akim.demaille@gmail.com>
Date: Sat, 1 Dec 2018 07:52:56 +0100
Subject: [PATCH] output: restore yyrhs and yyprhs

This was demanded several times.  See for instance:

- David M. Warme
  https://lists.gnu.org/archive/html/help-bison/2011-04/msg00003.html

- box12009
  http://lists.gnu.org/archive/html/bug-bison/2016-10/msg00001.html

Basically, this reverts:

- commit 3d3bc1fe30f356cf674a979409e86ea0f88de4a0
  Get rid of (yy)rhs and (yy)prhs

- commit d333175f63f402dbadb647175e40ad88bf1defb5
  Avoid compiler warning.

Note that since these tables are not needed in the generated parsers,
no skeleton requests them.  This change only brings back their
definition to M4, making it possible to user-defined skeletons to use
these tables.

* src/output.c (muscle_insert_item_number_table): Define.
(prepare_rules): Generate the rhs and prhs tables.
---
 src/output.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/src/output.c b/src/output.c
index 96295d17..a6517968 100644
--- a/src/output.c
+++ b/src/output.c
@@ -99,6 +99,7 @@ GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_int_table, int)
 GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_base_table, base_number)
 GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_rule_number_table, rule_number)
 GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_symbol_number_table, symbol_number)
+GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_item_number_table, item_number)
 GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_state_number_table, state_number)
 
 /*----------------------------------------------------------------.
@@ -200,14 +201,16 @@ prepare_symbols (void)
 }
 
 
-/*----------------------------------------------------------------.
-| Prepare the muscles related to the rules: r1, r2, rline, dprec, |
-| merger, immediate.                                              |
-`----------------------------------------------------------------*/
+/*-------------------------------------------------------------.
+| Prepare the muscles related to the rules: rhs, prhs, r1, r2, |
+| rline, dprec, merger, immediate.                             |
+`-------------------------------------------------------------*/
 
 static void
 prepare_rules (void)
 {
+  unsigned *prhs = xnmalloc (nrules, sizeof *prhs);
+  item_number *rhs = xnmalloc (nritems, sizeof *rhs);
   unsigned *rline = xnmalloc (nrules, sizeof *rline);
   symbol_number *r1 = xnmalloc (nrules, sizeof *r1);
   unsigned *r2 = xnmalloc (nrules, sizeof *r2);
@@ -215,14 +218,24 @@ prepare_rules (void)
   int *merger = xnmalloc (nrules, sizeof *merger);
   int *immediate = xnmalloc (nrules, sizeof *immediate);
 
+  /* Index in RHS.  */
+  unsigned i = 0;
   for (rule_number r = 0; r < nrules; ++r)
     {
+      /* Index of rule R in RHS. */
+      prhs[r] = i;
+      /* RHS of the rule R. */
+      for (item_number *rhsp = rules[r].rhs; 0 <= *rhsp; ++rhsp)
+	rhs[i++] = *rhsp;
+      /* Separator in RHS. */
+      rhs[i++] = -1;
+
+      /* Line where rule was defined. */
+      rline[r] = rules[r].location.start.line;
       /* LHS of the rule R. */
       r1[r] = rules[r].lhs->number;
       /* Length of rule R's RHS. */
-      r2[r] = rule_rhs_length (&rules[r]);
-      /* Line where rule was defined. */
-      rline[r] = rules[r].location.start.line;
+      r2[r] = rule_rhs_length(&rules[r]);
       /* Dynamic precedence (GLR).  */
       dprec[r] = rules[r].dprec;
       /* Merger-function index (GLR).  */
@@ -230,7 +243,10 @@ prepare_rules (void)
       /* Immediate reduction flags (GLR).  */
       immediate[r] = rules[r].is_predicate;
     }
+  aver (i == nritems);
 
+  muscle_insert_item_number_table ("rhs", rhs, ritem[0], 1, nritems);
+  muscle_insert_unsigned_int_table ("prhs", prhs, 0, 0, nrules);
   muscle_insert_unsigned_int_table ("rline", rline, 0, 0, nrules);
   muscle_insert_symbol_number_table ("r1", r1, 0, 0, nrules);
   muscle_insert_unsigned_int_table ("r2", r2, 0, 0, nrules);
@@ -241,6 +257,8 @@ prepare_rules (void)
   MUSCLE_INSERT_INT ("rules_number", nrules);
   MUSCLE_INSERT_INT ("max_left_semantic_context", max_left_semantic_context);
 
+  free (prhs);
+  free (rhs);
   free (rline);
   free (r1);
   free (r2);