* src/parse-gram.y: Define PERCENT_EXPECT_RR.

(declaration): Replace expected_conflicts with expected_sr_conflicts.
Add %expect-rr rule.

* src/scan-gram.l: Recognize %expect-rr.

* src/conflicts.h (expected_sr_conflicts): Rename from
expected_conflicts.
(expected_rr_conflicts): Declare.

* src/conflicts.c (expected_sr_conflicts): Rename from
expected_conflicts.
(expected_rr_conflicts): Define.
(conflicts_print): Check r/r conflicts against expected_rr_conflicts
for GLR parsers.
Use expected_sr_conflicts in place of expected_conflicts.
Warn if expected_rr_conflicts used in non-GLR parser.

* doc/bison.texinfo: Add documentation for %expect-rr.

ChangeLog

@@ -1,3 +1,25 @@
+2004-03-25  Paul Hilfinger  <hilfingr@tully.CS.Berkeley.EDU>
+
+	* src/parse-gram.y: Define PERCENT_EXPECT_RR.
+	(declaration): Replace expected_conflicts with expected_sr_conflicts.
+	Add %expect-rr rule.
+	
+	* src/scan-gram.l: Recognize %expect-rr.
+
+	* src/conflicts.h (expected_sr_conflicts): Rename from 
+	expected_conflicts.
+	(expected_rr_conflicts): Declare.	
+
+	* src/conflicts.c (expected_sr_conflicts): Rename from
+	expected_conflicts.
+	(expected_rr_conflicts): Define.
+	(conflicts_print): Check r/r conflicts against expected_rr_conflicts
+	for GLR parsers.
+	Use expected_sr_conflicts in place of expected_conflicts.
+	Warn if expected_rr_conflicts used in non-GLR parser.
+	
+	* doc/bison.texinfo: Add documentation for %expect-rr.
+	
 2004-03-08  Paul Eggert  <eggert@gnu.org>
 
 	Add support for hex token numbers.  Suggested by Odd Arild Olsen in

doc/bison.texinfo

@@ -223,7 +223,7 @@ Bison Declarations
 * Union Decl::        Declaring the set of all semantic value types.
 * Type Decl::         Declaring the choice of type for a nonterminal symbol.
 * Destructor Decl::   Declaring how symbols are freed.
-* Expect Decl::       Suppressing warnings about shift/reduce conflicts.
+* Expect Decl::       Suppressing warnings about parsing conflicts.
 * Start Decl::        Specifying the start symbol.
 * Pure Decl::         Requesting a reentrant parser.
 * Decl Summary::      Table of all Bison declarations.
@@ -3280,7 +3280,7 @@ Grammars}).
 * Union Decl::        Declaring the set of all semantic value types.
 * Type Decl::         Declaring the choice of type for a nonterminal symbol.
 * Destructor Decl::   Declaring how symbols are freed.
-* Expect Decl::       Suppressing warnings about shift/reduce conflicts.
+* Expect Decl::       Suppressing warnings about parsing conflicts.
 * Start Decl::        Specifying the start symbol.
 * Pure Decl::         Requesting a reentrant parser.
 * Decl Summary::      Table of all Bison declarations.
@@ -3560,6 +3560,7 @@ typefull: string;  // $$ = $1 applies, $1 is not destroyed.
 @cindex warnings, preventing
 @cindex conflicts, suppressing warnings of
 @findex %expect
+@findex %expect-rr
 
 Bison normally warns if there are any conflicts in the grammar
 (@pxref{Shift/Reduce, ,Shift/Reduce Conflicts}), but most real grammars
@@ -3580,6 +3581,18 @@ reduce/reduce conflicts.  The usual warning is
 given if there are either more or fewer conflicts, or if there are any
 reduce/reduce conflicts.
 
+For normal LALR(1) parsers, reduce/reduce conflicts are more serious,
+and should be eliminated entirely.  Bison will always report
+reduce/reduce conflicts for these parsers.  With GLR parsers, however,
+both shift/reduce and reduce/reduce are routine (otherwise, there
+would be no need to use GLR parsing).  Therefore, it is also possible
+to specify an expected number of reduce/reduce conflicts in GLR
+parsers, using the declaration:
+
+@example
+%expect-rr @var{n}
+@end example
+
 In general, using @code{%expect} involves these steps:
 
 @itemize @bullet

src/conflicts.c

@@ -36,7 +36,8 @@
 #include "symtab.h"
 
 /* -1 stands for not specified. */
-int expected_conflicts = -1;
+int expected_sr_conflicts = -1;
+int expected_rr_conflicts = -1;
 static char *conflicts = NULL;
 struct obstack solved_conflicts_obstack;
 
@@ -464,6 +465,7 @@ conflicts_print (void)
      not set, and then we want 0 SR, or else it is specified, in which
      case we want equality.  */
   bool src_ok = false;
+  bool rrc_ok = false;
 
   int src_total = 0;
   int rrc_total = 0;
@@ -480,11 +482,20 @@ conflicts_print (void)
 	}
   }
 
-  src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts);
+  if (! glr_parser && rrc_total > 0 && expected_rr_conflicts != -1)
+    {
+      warn (_("%expect-rr applies only to GLR parsers"));
+      expected_rr_conflicts = -1;
+    }
 
-  /* If there are no RR conflicts, and as many SR conflicts as
+  src_ok = 
+    src_total == (expected_sr_conflicts == -1 ? 0 : expected_sr_conflicts);
+  rrc_ok = 
+    rrc_total == (expected_rr_conflicts == -1 ? 0 : expected_rr_conflicts);
+
+  /* If there are as many RR conflicts and SR conflicts as
      expected, then there is nothing to report.  */
-  if (!rrc_total && src_ok)
+  if (rrc_ok && src_ok)
     return;
 
   /* Report the total number of conflicts on STDERR.  */
@@ -492,15 +503,18 @@ conflicts_print (void)
     fprintf (stderr, "%s: ", current_file);
   conflict_report (stderr, src_total, rrc_total);
 
-  if (expected_conflicts != -1)
+  if (expected_sr_conflicts != -1 || expected_rr_conflicts != -1)
     {
+      int sr = expected_sr_conflicts == -1 ? 0 : expected_sr_conflicts;
+      int rr = expected_rr_conflicts == -1 ? 0 : expected_rr_conflicts;
       if (! src_ok)
 	warn (ngettext ("expected %d shift/reduce conflict",
 			"expected %d shift/reduce conflicts",
-			expected_conflicts),
-	      expected_conflicts);
-      if (rrc_total)
-	warn (_("expected 0 reduce/reduce conflicts"));
+			sr), sr);
+      if (! rrc_ok)
+	warn (ngettext ("expected %d reduce/reduce conflict",
+			"expected %d reduce/reduce conflicts",
+			rr), rr);
     }
 }
 

src/conflicts.h

@@ -29,5 +29,6 @@ void conflicts_output (FILE *out);
 void conflicts_free (void);
 
 /* Were there conflicts? */
-extern int expected_conflicts;
+extern int expected_sr_conflicts;
+extern int expected_rr_conflicts;
 #endif /* !CONFLICTS_H_ */

src/parse-gram.h

@@ -50,33 +50,34 @@
      PERCENT_DEFINES = 275,
      PERCENT_ERROR_VERBOSE = 276,
      PERCENT_EXPECT = 277,
-     PERCENT_FILE_PREFIX = 278,
-     PERCENT_GLR_PARSER = 279,
-     PERCENT_INITIAL_ACTION = 280,
-     PERCENT_LEX_PARAM = 281,
-     PERCENT_LOCATIONS = 282,
-     PERCENT_NAME_PREFIX = 283,
-     PERCENT_NO_DEFAULT_PREC = 284,
-     PERCENT_NO_LINES = 285,
-     PERCENT_NONDETERMINISTIC_PARSER = 286,
-     PERCENT_OUTPUT = 287,
-     PERCENT_PARSE_PARAM = 288,
-     PERCENT_PURE_PARSER = 289,
-     PERCENT_SKELETON = 290,
-     PERCENT_START = 291,
-     PERCENT_TOKEN_TABLE = 292,
-     PERCENT_VERBOSE = 293,
-     PERCENT_YACC = 294,
-     TYPE = 295,
-     EQUAL = 296,
-     SEMICOLON = 297,
-     PIPE = 298,
-     ID = 299,
-     ID_COLON = 300,
-     PERCENT_PERCENT = 301,
-     PROLOGUE = 302,
-     EPILOGUE = 303,
-     BRACED_CODE = 304
+     PERCENT_EXPECT_RR = 278,
+     PERCENT_FILE_PREFIX = 279,
+     PERCENT_GLR_PARSER = 280,
+     PERCENT_INITIAL_ACTION = 281,
+     PERCENT_LEX_PARAM = 282,
+     PERCENT_LOCATIONS = 283,
+     PERCENT_NAME_PREFIX = 284,
+     PERCENT_NO_DEFAULT_PREC = 285,
+     PERCENT_NO_LINES = 286,
+     PERCENT_NONDETERMINISTIC_PARSER = 287,
+     PERCENT_OUTPUT = 288,
+     PERCENT_PARSE_PARAM = 289,
+     PERCENT_PURE_PARSER = 290,
+     PERCENT_SKELETON = 291,
+     PERCENT_START = 292,
+     PERCENT_TOKEN_TABLE = 293,
+     PERCENT_VERBOSE = 294,
+     PERCENT_YACC = 295,
+     TYPE = 296,
+     EQUAL = 297,
+     SEMICOLON = 298,
+     PIPE = 299,
+     ID = 300,
+     ID_COLON = 301,
+     PERCENT_PERCENT = 302,
+     PROLOGUE = 303,
+     EPILOGUE = 304,
+     BRACED_CODE = 305
    };
 #endif
 #define GRAM_EOF 0
@@ -100,39 +101,40 @@
 #define PERCENT_DEFINES 275
 #define PERCENT_ERROR_VERBOSE 276
 #define PERCENT_EXPECT 277
-#define PERCENT_FILE_PREFIX 278
-#define PERCENT_GLR_PARSER 279
-#define PERCENT_INITIAL_ACTION 280
-#define PERCENT_LEX_PARAM 281
-#define PERCENT_LOCATIONS 282
-#define PERCENT_NAME_PREFIX 283
-#define PERCENT_NO_DEFAULT_PREC 284
-#define PERCENT_NO_LINES 285
-#define PERCENT_NONDETERMINISTIC_PARSER 286
-#define PERCENT_OUTPUT 287
-#define PERCENT_PARSE_PARAM 288
-#define PERCENT_PURE_PARSER 289
-#define PERCENT_SKELETON 290
-#define PERCENT_START 291
-#define PERCENT_TOKEN_TABLE 292
-#define PERCENT_VERBOSE 293
-#define PERCENT_YACC 294
-#define TYPE 295
-#define EQUAL 296
-#define SEMICOLON 297
-#define PIPE 298
-#define ID 299
-#define ID_COLON 300
-#define PERCENT_PERCENT 301
-#define PROLOGUE 302
-#define EPILOGUE 303
-#define BRACED_CODE 304
+#define PERCENT_EXPECT_RR 278
+#define PERCENT_FILE_PREFIX 279
+#define PERCENT_GLR_PARSER 280
+#define PERCENT_INITIAL_ACTION 281
+#define PERCENT_LEX_PARAM 282
+#define PERCENT_LOCATIONS 283
+#define PERCENT_NAME_PREFIX 284
+#define PERCENT_NO_DEFAULT_PREC 285
+#define PERCENT_NO_LINES 286
+#define PERCENT_NONDETERMINISTIC_PARSER 287
+#define PERCENT_OUTPUT 288
+#define PERCENT_PARSE_PARAM 289
+#define PERCENT_PURE_PARSER 290
+#define PERCENT_SKELETON 291
+#define PERCENT_START 292
+#define PERCENT_TOKEN_TABLE 293
+#define PERCENT_VERBOSE 294
+#define PERCENT_YACC 295
+#define TYPE 296
+#define EQUAL 297
+#define SEMICOLON 298
+#define PIPE 299
+#define ID 300
+#define ID_COLON 301
+#define PERCENT_PERCENT 302
+#define PROLOGUE 303
+#define EPILOGUE 304
+#define BRACED_CODE 305
 
 
 
 
 #if ! defined (YYSTYPE) && ! defined (YYSTYPE_IS_DECLARED)
-#line 80 "parse-gram.y"
+#line 80 "../../src/parse-gram.y"
 typedef union YYSTYPE {
   symbol *symbol;
   symbol_list *list;
@@ -142,7 +144,7 @@ typedef union YYSTYPE {
   uniqstr uniqstr;
 } YYSTYPE;
 /* Line 1285 of yacc.c.  */
-#line 146 "y.tab.h"
+#line 148 "y.tab.h"
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */
 # define YYSTYPE_IS_DECLARED 1
 # define YYSTYPE_IS_TRIVIAL 1

src/parse-gram.y

@@ -120,6 +120,7 @@ int current_prec = 0;
   PERCENT_DEFINES         "%defines"
   PERCENT_ERROR_VERBOSE   "%error-verbose"
   PERCENT_EXPECT          "%expect"
+  PERCENT_EXPECT_RR	  "%expect-rr"
   PERCENT_FILE_PREFIX     "%file-prefix"
   PERCENT_GLR_PARSER      "%glr-parser"
   PERCENT_INITIAL_ACTION  "%initial-action {...}"
@@ -189,7 +190,8 @@ declaration:
 | "%define" string_content string_content  { muscle_insert ($2, $3); }
 | "%defines"                               { defines_flag = true; }
 | "%error-verbose"                         { error_verbose = true; }
-| "%expect" INT                            { expected_conflicts = $2; }
+| "%expect" INT                            { expected_sr_conflicts = $2; }
+| "%expect-rr" INT 			   { expected_rr_conflicts = $2; }
 | "%file-prefix" "=" string_content        { spec_file_prefix = $3; }
 | "%glr-parser"
   {

src/scan-gram.l

@@ -190,6 +190,7 @@ splice	 (\\[ \f\t\v]*\n)*
   "%dprec"		  return PERCENT_DPREC;
   "%error"[-_]"verbose"   return PERCENT_ERROR_VERBOSE;
   "%expect"               return PERCENT_EXPECT;
+  "%expect"[-_]"rr"	  return PERCENT_EXPECT_RR;
   "%file-prefix"          return PERCENT_FILE_PREFIX;
   "%fixed"[-_]"output"[-_]"files"   return PERCENT_YACC;
   "%initial-action"       token_type = PERCENT_INITIAL_ACTION; BEGIN SC_PRE_CODE;