skeletons: avoid b4_error_verbose_if, which is confusing

parse.error has more than two possible values.

* data/skeletons/bison.m4 (b4_error_verbose_if, b4_error_verbose_flag):
Remove.
(b4_parse_error_case, b4_parse_error_bmatch): New.
Adjust dependencies.

data/skeletons/bison.m4

@@ -1016,20 +1016,24 @@ m4_define([b4_bison_locations_if],
 [b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [], [$1])])])
 
 
-# b4_error_verbose_if([IF-ERRORS-ARE-VERBOSE], [IF-NOT])
+
+# %define parse.error "(custom|detailed|simple|verbose)"
 # ------------------------------------------------------
-# Map %define parse.error "(custom|detailed|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]],
                                  [[custom]], [[detailed]], [[simple]], [[verbose]]]])
-m4_define([b4_error_verbose_flag],
-          [m4_case(b4_percent_define_get([[parse.error]]),
-                   [custom],   [[1]],
-                   [detailed], [[1]],
-                   [simple],   [[0]],
-                   [verbose],  [[1]])])
-b4_define_flag_if([error_verbose])
+
+# b4_parse_error_case(CASE1, THEN1, CASE2, THEN2, ..., ELSE)
+# ----------------------------------------------------------
+m4_define([b4_parse_error_case],
+[m4_case(b4_percent_define_get([[parse.error]]), $@)])
+
+# b4_parse_error_bmatch(PATTERN1, THEN1, PATTERN2, THEN2, ..., ELSE)
+# ------------------------------------------------------------------
+m4_define([b4_parse_error_bmatch],
+[m4_bmatch(b4_percent_define_get([[parse.error]]), $@)])
+
+
 
 # b4_variant_if([IF-VARIANT-ARE-USED], [IF-NOT])
 # ----------------------------------------------

data/skeletons/glr.c

@@ -607,13 +607,12 @@ yyMemoryExhausted (yyGLRStack* yystackp)
   YYLONGJMP (yystackp->yyexception_buffer, 2);
 }
 
-#if ]b4_error_verbose_if([[1]], [b4_api_PREFIX[DEBUG || ]b4_token_table_flag])[
+#if ]b4_parse_error_case([simple], [b4_api_PREFIX[DEBUG || ]b4_token_table_flag], [[1]])[
 /* The user-facing name of the symbol whose (internal) number is
    YYSYMBOL.  No bounds checking.  */
 static const char *yysymbol_name (yySymbol yysymbol) YY_ATTRIBUTE_UNUSED;
 
-]m4_bmatch(b4_percent_define_get([[parse.error]]),
-           [simple\|verbose],
+]b4_parse_error_bmatch([simple\|verbose],
 [[/* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
    First, the terminals, then, starting at YYNTOKENS, nonterminals.  */
 static const char *const yytname[] =

data/skeletons/lalr1.cc

@@ -284,8 +284,7 @@ m4_define([b4_shared_declarations],
 
     // Tables.
 ]b4_parser_tables_declare[
-]m4_case(b4_percent_define_get([[parse.error]]),
-         [verbose], [[
+]b4_parse_error_case([verbose], [[
     /// Convert the symbol name \a n to a form suitable for a diagnostic.
     static std::string yytnamerr_ (const char *n);
 
@@ -560,7 +559,7 @@ m4_if(b4_prefix, [yy], [],
 #define YYERROR         goto yyerrorlab
 #define YYRECOVERING()  (!!yyerrstatus_)
 
-]b4_namespace_open[]b4_error_verbose_if([[
+]b4_namespace_open[]b4_parse_error_case([verbose], [[
 
   /* Return YYSTR after stripping away unnecessary quotes and
      backslashes, so that it's suitable for yyerror.  The heuristic is
@@ -1311,10 +1310,10 @@ b4_dollar_popdef])[]dnl
 
   // Generate an error message.
   std::string
-  ]b4_parser_class[::yysyntax_error_ (]dnl
-b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
+]b4_parser_class[::yysyntax_error_ (]b4_parse_error_case([verbose],
+                                    [state_type yystate, const symbol_type& yyla],
                                     [state_type, const symbol_type&])[) const
-  {]b4_error_verbose_if([[
+  {]b4_parse_error_case([verbose], [[
     // Number of reported tokens (one for the "unexpected", one per
     // "expected").
     std::ptrdiff_t yycount = 0;

data/skeletons/lalr1.d

@@ -679,7 +679,7 @@ m4_popdef([b4_at_dollar])])dnl
 
   // Generate an error message.
   private final string yysyntax_error (int yystate, int tok)
-  {]b4_error_verbose_if([[
+  {]b4_parse_error_case([verbose], [[
     /* There are many possibilities here to consider:
        - Assume YYFAIL is not used.  It's too flawed to consider.
          See

data/skeletons/yacc.c

@@ -429,7 +429,7 @@ typedef int yy_state_fast_t;
 ]],
 [[#define YY_ASSERT(E) ((void) (0 && (E)))]])[
 
-#if ]b4_lac_if([[1]], [b4_error_verbose_if([[1]], [[!defined yyoverflow]])])[
+#if ]b4_lac_if([[1]], [b4_parse_error_case([simple], [[!defined yyoverflow]], [[1]])])[
 
 /* The parser invokes alloca or malloc; define the necessary symbols.  */]dnl
 b4_push_if([], [b4_lac_if([], [[
@@ -496,7 +496,7 @@ void free (void *); /* INFRINGES ON USER NAME SPACE */
 #  endif
 # endif]b4_lac_if([[
 # define YYCOPY_NEEDED 1]])[
-#endif]b4_lac_if([], [b4_error_verbose_if([], [[/* !defined yyoverflow */]])])[
+#endif]b4_lac_if([], [b4_parse_error_case([simple], [[/* !defined yyoverflow */]])])[
 
 #if (! defined yyoverflow \
      && (! defined __cplusplus \
@@ -602,7 +602,7 @@ static const ]b4_int_type_for([b4_translate])[ yytranslate[] =
      [[YYRLINE[YYN] -- Source line where rule number YYN was defined.]])[
 #endif
 
-#if ]b4_error_verbose_if([[1]], [b4_api_PREFIX[DEBUG || ]b4_token_table_flag])[
+#if ]b4_parse_error_case([simple], [b4_api_PREFIX[DEBUG || ]b4_token_table_flag], [[1]])[
 /* The user-facing name of the symbol whose (internal) number is
    YYSYMBOL.  No bounds checking.  */
 static const char *yysymbol_name (int yysymbol) YY_ATTRIBUTE_UNUSED;
@@ -2010,7 +2010,7 @@ yyabortlab:
   goto yyreturn;
 
 
-#if ]b4_lac_if([[1]], [b4_error_verbose_if([[1]], [[!defined yyoverflow]])])[
+#if ]b4_lac_if([[1]], [b4_parse_error_case([simple], [[!defined yyoverflow]], [[1]])])[
 /*-------------------------------------------------.
 | yyexhaustedlab -- memory exhaustion comes here.  |
 `-------------------------------------------------*/