variables: parse.error

Implement, document, and test the replacement of %error-verbose
by %define parse.error "verbose".

	* data/bison.m4 (b4_error_verbose_if): Reimplement to track the
	values of the parse.error variable.
	Make "simple" its default value.
	Check the valid values.
	* src/parse-gram.y: Use %define parse.error.
	(PERCENT_ERROR_VERBOSE): New token.
	Support it.
	* src/scan-gram.l: Support %error-verbose.

	* doc/bison.texinfo (Decl Summary): Replace the documentation of
	%define error-verbose by that of %define parse.error.
	* NEWS: Document it.

	* tests/actions.at, tests/calc.at: Use parse.error instead of
	%error-verbose.

8 files changed, 119 insertions, 62 deletions

diff --git a/ChangeLog b/ChangeLog
index 2293e62a..797a4932 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,25 @@
+2009-06-29  Akim Demaille  <demaille@gostai.com>
+
+	variables: parse.error
+
+	Implement, document, and test the replacement of %error-verbose
+	by %define parse.error "verbose".
+	* data/bison.m4 (b4_error_verbose_if): Reimplement to track the
+	values of the parse.error variable.
+	Make "simple" its default value.
+	Check the valid values.
+	* src/parse-gram.y: Use %define parse.error.
+	(PERCENT_ERROR_VERBOSE): New token.
+	Support it.
+	* src/scan-gram.l: Support %error-verbose.
+
+	* doc/bison.texinfo (Decl Summary): Replace the documentation of
+	%define error-verbose by that of %define parse.error.
+	* NEWS: Document it.
+
+	* tests/actions.at, tests/calc.at: Use parse.error instead of
+	%error-verbose.
+
 2009-06-27  Alex Rozenman  <rozenman@gmail.com>
 
 	Implement support for named symbol references.
diff --git a/NEWS b/NEWS
index d5e40d55..aa8c7ea2 100644
--- a/NEWS
+++ b/NEWS
@@ -30,6 +30,12 @@ Bison News
   The "namespace" variable is renamed "api.namespace".  Backward
   compatibility is ensured, but upgrading is recommended.
 
+** Variable parse.error
+
+  The variable error controls the verbosity of error messages.  The
+  use of the %error-verbose directive is deprecated in favor of
+  %define parse.error "verbose".
+
 * Changes in version 2.5 (????-??-??):
 
 ** IELR(1) and Canonical LR(1) Support
diff --git a/data/bison.m4 b/data/bison.m4
index 56610570..c8d08528 100644
--- a/data/bison.m4
+++ b/data/bison.m4
@@ -718,11 +718,9 @@ b4_percent_define_if_define_([$1], $[1], $[2])])
 
 # b4_parse_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
 # b4_parse_trace_if([IF-DEBUG-TRACES-ARE-ENABLED], [IF-NOT])
-# b4_error_verbose_if([IF-ERRORS-ARE-VERBOSE], [IF-NOT])
 # b4_lex_symbol_if([IF-YYLEX-RETURNS-A-COMPLETE-SYMBOL], [IF-NOT])
 # b4_variant_if([IF-VARIANT-ARE-USED], [IF-NOT])
 # ----------------------------------------------
-b4_percent_define_if_define([error-verbose])
 b4_percent_define_if_define([lex_symbol])
 b4_percent_define_if_define([locations])     # Whether locations are tracked.
 b4_percent_define_if_define([parse.assert])
@@ -730,6 +728,18 @@ b4_percent_define_if_define([parse.trace])
 b4_percent_define_if_define([variant])
 
 
+# b4_error_verbose_if([IF-ERRORS-ARE-VERBOSE], [IF-NOT])
+# ------------------------------------------------------
+# Map %define parse.error "(simple|verbose)" to b4_error_verbose_if and
+# b4_error_verbose_flag.
+b4_percent_define_default([[parse.error]], [[simple]])
+b4_percent_define_check_values([[[[parse.error]],
+                               [[simple]], [[verbose]]]])
+m4_case(b4_percent_define_get([[parse.error]]),
+        [simple],  [m4_define([b4_error_verbose_flag], [[0]])],
+        [verbose], [m4_define([b4_error_verbose_flag], [[1]])])
+b4_define_flag_if([error_verbose])
+
 
 # b4_percent_define_check_values(VALUES)
 # --------------------------------------
diff --git a/doc/bison.texinfo b/doc/bison.texinfo
index f0541814..6ed33668 100644
--- a/doc/bison.texinfo
+++ b/doc/bison.texinfo
@@ -4998,23 +4998,6 @@ empty
 @c api.tokens.prefix
 
 
-@item error-verbose
-@findex %define error-verbose
-@itemize
-@item Languages(s):
-all.
-@item Purpose:
-Enable the generation of more verbose error messages than a instead of
-just plain @w{@code{"syntax error"}}.  @xref{Error Reporting, ,The Error
-Reporting Function @code{yyerror}}.
-@item Accepted Values:
-Boolean
-@item Default Value:
-@code{false}
-@end itemize
-@c error-verbose
-
-
 @item lr.default-reductions
 @cindex default reductions
 @findex %define lr.default-reductions
@@ -5209,6 +5192,8 @@ facilitate the development of a grammar.
 Obsoleted by @code{api.namespace}
 @c namespace
 
+
+@c ================================================== parse.assert
 @item parse.assert
 @findex %define parse.assert
 
@@ -5225,6 +5210,34 @@ destroyed properly.  This option checks these constraints.
 @end itemize
 @c parse.assert
 
+
+@c ================================================== parse.error
+@item parse.error
+@findex %define parse.error
+@itemize
+@item Languages(s):
+all.
+@item Purpose:
+Control the kind of error messages passed to the error reporting
+function.  @xref{Error Reporting, ,The Error Reporting Function
+@code{yyerror}}.
+@item Accepted Values:
+@itemize
+@item @code{"simple"}
+Error messages passed to @code{yyerror} are simply @w{@code{"syntax
+error"}}.
+@item @code{"verbose"}
+Error messages report the unexpected token, and possibly the expected
+ones.
+@end itemize
+
+@item Default Value:
+@code{simple}
+@end itemize
+@c parse.error
+
+
+@c ================================================== parse.trace
 @item parse.trace
 @findex %define parse.trace
 
@@ -5884,7 +5897,7 @@ int yyparse (int *nastiness, int *randomness);
 @cindex parse error
 @cindex syntax error
 
-The Bison parser detects a @dfn{syntax error} or @dfn{parse error}
+The Bison parser detects a @dfn{syntax error} (or @dfn{parse error})
 whenever it reads a token which cannot satisfy any syntax rule.  An
 action in the grammar can also explicitly proclaim an error, using the
 macro @code{YYERROR} (@pxref{Action Features, ,Special Features for Use
@@ -5896,8 +5909,8 @@ called by @code{yyparse} whenever a syntax error is found, and it
 receives one argument.  For a syntax error, the string is normally
 @w{@code{"syntax error"}}.
 
-@findex %define error-verbose
-If you invoke the directive @samp{%define error-verbose} in the Bison
+@findex %define parse.error
+If you invoke @samp{%define parse.error "verbose"} in the Bison
 declarations section (@pxref{Bison Declarations, ,The Bison Declarations
 Section}), then Bison provides a more verbose and specific error message
 string instead of just plain @w{@code{"syntax error"}}.
@@ -8821,7 +8834,7 @@ error messages.
 @comment file: calc++-parser.yy
 @example
 %define parse.trace
-%define error-verbose
+%define parse.error "verbose"
 @end example
 
 @noindent
@@ -9309,7 +9322,7 @@ Run the syntactic analysis, and return @code{true} on success,
 @deftypemethod {YYParser} {boolean} getErrorVerbose ()
 @deftypemethodx {YYParser} {void} setErrorVerbose (boolean @var{verbose})
 Get or set the option to produce verbose error messages.  These are only
-available with the @samp{%define error-verbose} directive, which also turn on
+available with @samp{%define parse.error "verbose"}, which also turns on
 verbose error messages.
 @end deftypemethod
 
@@ -10238,7 +10251,7 @@ token is reset to the token that originally caused the violation.
 @end deffn
 
 @deffn {Directive} %error-verbose
-An obsolete directive standing for @samp{%define error-verbose}.
+An obsolete directive standing for @samp{%define parse.error "verbose"}.
 @end deffn
 
 @deffn {Directive} %file-prefix "@var{prefix}"
@@ -10444,8 +10457,8 @@ An obsolete macro used in the @file{yacc.c} skeleton, that you define
 with @code{#define} in the prologue to request verbose, specific error
 message strings when @code{yyerror} is called.  It doesn't matter what
 definition you use for @code{YYERROR_VERBOSE}, just whether you define
-it.  Using @samp{%define error-verbose} is preferred (@pxref{Error
-Reporting, ,The Error Reporting Function @code{yyerror}}).
+it.  Using @samp{%define parse.error "verbose"} is preferred
+(@pxref{Error Reporting, ,The Error Reporting Function @code{yyerror}}).
 @end deffn
 
 @deffn {Macro} YYINITDEPTH
diff --git a/src/parse-gram.y b/src/parse-gram.y
index 0fbb8cbd..a10c32ed 100644
--- a/src/parse-gram.y
+++ b/src/parse-gram.y
@@ -78,7 +78,7 @@ static int current_prec = 0;
 %defines
 %locations
 %pure-parser
-%error-verbose
+%define parse.error "verbose"
 %name-prefix="gram_"
 %expect 0
 
@@ -134,6 +134,7 @@ static int current_prec = 0;
   PERCENT_DEFAULT_PREC    "%default-prec"
   PERCENT_DEFINE          "%define"
   PERCENT_DEFINES         "%defines"
+  PERCENT_ERROR_VERBOSE   "%error-verbose"
   PERCENT_EXPECT          "%expect"
   PERCENT_EXPECT_RR	  "%expect-rr"
   PERCENT_FLAG            "%<flag>"
@@ -243,6 +244,11 @@ prologue_declaration:
       defines_flag = true;
       spec_defines_file = xstrdup ($2);
     }
+| "%error-verbose"
+    {
+      muscle_percent_define_insert ("parse.error", @1, "verbose",
+                                    MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
+    }
 | "%expect" INT                    { expected_sr_conflicts = $2; }
 | "%expect-rr" INT		   { expected_rr_conflicts = $2; }
 | "%file-prefix" STRING            { spec_file_prefix = $2; }
diff --git a/src/scan-gram.l b/src/scan-gram.l
index f71409ed..279bba97 100644
--- a/src/scan-gram.l
+++ b/src/scan-gram.l
@@ -194,7 +194,7 @@ splice	 (\\[ \f\t\v]*\n)*
   "%defines"                        return PERCENT_DEFINES;
   "%destructor"                     return PERCENT_DESTRUCTOR;
   "%dprec"                          return PERCENT_DPREC;
-  "%error"[-_]"verbose"             RETURN_PERCENT_FLAG("error-verbose");
+  "%error"[-_]"verbose"             return PERCENT_ERROR_VERBOSE;
   "%expect"                         return PERCENT_EXPECT;
   "%expect"[-_]"rr"                 return PERCENT_EXPECT_RR;
   "%file-prefix"                    return PERCENT_FILE_PREFIX;
diff --git a/tests/actions.at b/tests/actions.at
index 371cf84f..be52791c 100644
--- a/tests/actions.at
+++ b/tests/actions.at
@@ -29,7 +29,7 @@ AT_SETUP([Mid-rule actions])
 # action.
 
 AT_DATA_GRAMMAR([[input.y]],
-[[%define error-verbose
+[[%define parse.error "verbose"
 %debug
 %{
 # include <stdio.h>
@@ -93,7 +93,7 @@ AT_CLEANUP
 AT_SETUP([Exotic Dollars])
 
 AT_DATA_GRAMMAR([[input.y]],
-[[%define error-verbose
+[[%define parse.error "verbose"
 %debug
 %{
 # include <stdio.h>
@@ -557,7 +557,7 @@ m4_define([AT_CHECK_PRINTER_AND_DESTRUCTOR],
 
 $3
 _AT_CHECK_PRINTER_AND_DESTRUCTOR($[1], $[2], $[3], $[4],
-[%define error-verbose
+[%define parse.error "verbose"
 %debug
 %verbose
 %locations
@@ -588,7 +588,7 @@ AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser], [with union])
 AT_SETUP([Default tagless %printer and %destructor])
 
 AT_DATA_GRAMMAR([[input.y]],
-[[%define error-verbose
+[[%define parse.error "verbose"
 %debug
 %locations
 %initial-action {
@@ -706,7 +706,7 @@ AT_CLEANUP
 AT_SETUP([Default tagged and per-type %printer and %destructor])
 
 AT_DATA_GRAMMAR([[input.y]],
-[[%define error-verbose
+[[%define parse.error "verbose"
 %debug
 
 %{
@@ -850,7 +850,7 @@ m4_define([_AT_CHECK_DEFAULT_PRINTER_AND_DESTRUCTOR_FOR_END_TOKEN],
   [m4_pushdef([kind], [*]) m4_pushdef([not_kind], [])])
 
 AT_DATA_GRAMMAR([[input]]$1[[.y]],
-[[%define error-verbose
+[[%define parse.error "verbose"
 %debug
 %locations
 %initial-action {
diff --git a/tests/calc.at b/tests/calc.at
index 24a50800..9eee68d6 100644
--- a/tests/calc.at
+++ b/tests/calc.at
@@ -401,7 +401,7 @@ AT_PARSER_CHECK([./calc input], 0, [], [stderr])
 # If BISON-OPTIONS contains `%location', then make sure the ERROR-LOCATION
 # is correctly output on stderr.
 #
-# If BISON-OPTIONS contains `%error-verbose', then make sure the
+# If BISON-OPTIONS contains `%define parse.error "verbose"', then make sure the
 # IF-YYERROR-VERBOSE message is properly output after `syntax error, '
 # on STDERR.
 #
@@ -443,7 +443,7 @@ AT_YYERROR_SEES_LOC_IF([],
 [[sed 's/^[-0-9.]*: //' expout >at-expout
 mv at-expout expout]])
 # 4. If error-verbose is not used, strip the`, unexpected....' part.
-m4_bmatch([$1], [%error-verbose], [],
+m4_bmatch([$1], [%define parse.error "verbose"], [],
 [[sed 's/syntax error, .*$/syntax error/' expout >at-expout
 mv at-expout expout]])
 # 5. Check
@@ -572,22 +572,22 @@ AT_CHECK_CALC_LALR([%locations])
 AT_CHECK_CALC_LALR([%name-prefix="calc"]) dnl test deprecated `='
 AT_CHECK_CALC_LALR([%verbose])
 AT_CHECK_CALC_LALR([%yacc])
-AT_CHECK_CALC_LALR([%error-verbose])
+AT_CHECK_CALC_LALR([%define parse.error "verbose"])
 
 AT_CHECK_CALC_LALR([%define api.pure %locations])
 AT_CHECK_CALC_LALR([%define api.push-pull "both" %define api.pure %locations])
-AT_CHECK_CALC_LALR([%error-verbose %locations])
+AT_CHECK_CALC_LALR([%define parse.error "verbose" %locations])
 
-AT_CHECK_CALC_LALR([%error-verbose %locations %defines %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR([%error-verbose %locations %defines %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define parse.error "verbose" %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define parse.error "verbose" %locations %defines %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
 
 AT_CHECK_CALC_LALR([%debug])
-AT_CHECK_CALC_LALR([%error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_LALR([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR([%define api.push-pull "both" %define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define api.pure %define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define api.push-pull "both" %define api.pure %define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_LALR([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_LALR([%define api.pure %define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
 
 
 # ----------------------- #
@@ -611,20 +611,20 @@ AT_CHECK_CALC_GLR([%locations])
 AT_CHECK_CALC_GLR([%name-prefix "calc"])
 AT_CHECK_CALC_GLR([%verbose])
 AT_CHECK_CALC_GLR([%yacc])
-AT_CHECK_CALC_GLR([%error-verbose])
+AT_CHECK_CALC_GLR([%define parse.error "verbose"])
 
 AT_CHECK_CALC_GLR([%define api.pure %locations])
-AT_CHECK_CALC_GLR([%error-verbose %locations])
+AT_CHECK_CALC_GLR([%define parse.error "verbose" %locations])
 
-AT_CHECK_CALC_GLR([%error-verbose %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR([%define parse.error "verbose" %locations %defines %name-prefix "calc" %verbose %yacc])
 
 AT_CHECK_CALC_GLR([%debug])
-AT_CHECK_CALC_GLR([%error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_GLR([%error-verbose %debug %locations %defines %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
+AT_CHECK_CALC_GLR([%define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR([%define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
 
-AT_CHECK_CALC_GLR([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR([%define api.pure %define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_GLR([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_GLR([%define api.pure %define parse.error "verbose" %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
 
 
 # ----------------------------- #
@@ -645,14 +645,14 @@ m4_define([AT_CHECK_CALC_LALR1_CC],
 
 AT_CHECK_CALC_LALR1_CC([])
 AT_CHECK_CALC_LALR1_CC([%locations])
-AT_CHECK_CALC_LALR1_CC([%locations %error-verbose %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR1_CC([%locations %define parse.error "verbose" %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_LALR1_CC([%locations %error-verbose %debug %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR1_CC([%locations %define parse.error "verbose" %debug %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %error-verbose %debug %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %error-verbose %debug %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
+AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %define parse.error "verbose" %debug %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %define parse.error "verbose" %debug %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
 
-AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %error-verbose %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_LALR1_CC([%locations %pure-parser %define parse.error "verbose" %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
 
 
 
@@ -673,12 +673,12 @@ m4_define([AT_CHECK_CALC_GLR_CC],
 [AT_CHECK_CALC([%language "C++" %glr-parser %defines %locations] $@)])
 
 AT_CHECK_CALC_GLR_CC([])
-AT_CHECK_CALC_GLR_CC([%error-verbose %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR_CC([%define parse.error "verbose" %name-prefix "calc" %verbose %yacc])
 
 AT_CHECK_CALC_GLR_CC([%debug])
-AT_CHECK_CALC_GLR_CC([%error-verbose %debug %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR_CC([%define parse.error "verbose" %debug %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_GLR_CC([%pure-parser %error-verbose %debug %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_GLR_CC([%pure-parser %error-verbose %debug %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
+AT_CHECK_CALC_GLR_CC([%pure-parser %define parse.error "verbose" %debug %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR_CC([%pure-parser %define parse.error "verbose" %debug %name-prefix "calc" %define api.tokens.prefix "TOK_" %verbose %yacc])
 
-AT_CHECK_CALC_GLR_CC([%pure-parser %error-verbose %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_GLR_CC([%pure-parser %define parse.error "verbose" %debug %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])