[PATCH 3/7] yacc.c: declare and initialize and the same time

[Akim Demaille]

In order to factor the code of push and pull parsers, the declaration
of the parser's state variable was common (being local variable in
pull parsers, and struct members in push parsers).  This result in
rather poor style in pull parser, with first variable declarations,
and then their initializations.

The initialization is about to differ between push and pull parsers,
so it is no longer worth keeping both cases together.

* data/skeletons/yacc.c (b4_declare_parser_state_variables): Accept an
argument, and when it is set, initialize the variables.
Adjust dependencies.
---
 data/skeletons/yacc.c | 54 +++++++++++++++++++++----------------------
 1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/data/skeletons/yacc.c b/data/skeletons/yacc.c
index 3aa56604..9a4abeac 100644
--- a/data/skeletons/yacc.c
+++ b/data/skeletons/yacc.c
@@ -176,48 +176,47 @@ YYLTYPE yylloc]b4_yyloc_default[;]])[
 int yynerrs;]])])
 
 
-# b4_declare_parser_state_variables
-# ---------------------------------
+# b4_declare_parser_state_variables([INIT])
+# -----------------------------------------
 # Declare all the variables that are needed to maintain the parser state
 # between calls to yypush_parse.
+# If INIT is non-null, initialize these variables.
 m4_define([b4_declare_parser_state_variables],
 [b4_pure_if([[
     /* Number of syntax errors so far.  */
-    int yynerrs;
+    int yynerrs]m4_ifval([$1], [ = 0])[;
 ]])[
-    yy_state_fast_t yystate;
+    yy_state_fast_t yystate]m4_ifval([$1], [ = 0])[;
     /* Number of tokens to shift before error messages enabled.  */
-    int yyerrstatus;
-
-    /* The stacks and their tools:
-       'yyss': related to states.
-       'yyvs': related to semantic values.]b4_locations_if([[
-       'yyls': related to locations.]])[
+    int yyerrstatus]m4_ifval([$1], [ = 0])[;
 
-       Refer to the stacks through separate pointers, to allow yyoverflow
+    /* Refer to the stacks through separate pointers, to allow yyoverflow
        to reallocate them elsewhere.  */
 
     /* Their size.  */
-    YYPTRDIFF_T yystacksize;
+    YYPTRDIFF_T yystacksize]m4_ifval([$1], [ = YYINITDEPTH])[;
 
-    /* The state stack.  */
+    /* The state stack: array, bottom, top.  */
     yy_state_t yyssa[YYINITDEPTH];
-    yy_state_t *yyss;
-    yy_state_t *yyssp;
+    yy_state_t *yyss]m4_ifval([$1], [ = yyssa])[;
+    yy_state_t *yyssp]m4_ifval([$1], [ = yyss])[;
 
-    /* The semantic value stack.  */
+    /* The semantic value stack: array, bottom, top.  */
     YYSTYPE yyvsa[YYINITDEPTH];
-    YYSTYPE *yyvs;
-    YYSTYPE *yyvsp;]b4_locations_if([[
+    YYSTYPE *yyvs]m4_ifval([$1], [ = yyvsa])[;
+    YYSTYPE *yyvsp]m4_ifval([$1], [ = yyvs])[;]b4_locations_if([[
 
-    /* The location stack.  */
+    /* The location stack: array, bottom, top.  */
     YYLTYPE yylsa[YYINITDEPTH];
-    YYLTYPE *yyls;
-    YYLTYPE *yylsp;]])[]b4_lac_if([[
+    YYLTYPE *yyls]m4_ifval([$1], [ = yylsa])[;
+    YYLTYPE *yylsp]m4_ifval([$1], [ = yyls])[;]])[]b4_lac_if([[
 
     yy_state_t 
yyesa@{]b4_percent_define_get([[parse.lac.es-capacity-initial]])[@};
-    yy_state_t *yyes;
-    YYPTRDIFF_T yyes_capacity;]])])
+    yy_state_t *yyes]m4_ifval([$1], [ = yyesa])[;
+    YYPTRDIFF_T yyes_capacity][]m4_ifval([$1],
+            [m4_do([ = 
b4_percent_define_get([[parse.lac.es-capacity-initial]]) < YYMAXDEPTH],
+                   [ ? 
b4_percent_define_get([[parse.lac.es-capacity-initial]])],
+                   [ : YYMAXDEPTH])])[;]])])
 
 
 # b4_initialize_parser_state_variables
@@ -1543,7 +1542,7 @@ yyparse (]m4_ifset([b4_parse_param], 
[b4_formals(b4_parse_param)], [void])[)]])[
   YYSTYPE yypushed_val = yylval;]b4_locations_if([[
   YYLTYPE yypushed_loc = yylloc;]])
 ])],
-  [b4_declare_parser_state_variables
+  [b4_declare_parser_state_variables([init])
 ])b4_lac_if([[
   /* Whether LAC context is established.  A Boolean.  */
   int yy_lac_established = 0;]])[
@@ -1570,14 +1569,13 @@ yyparse (]m4_ifset([b4_parse_param], 
[b4_formals(b4_parse_param)], [void])[)]])[
 
   /* The number of symbols on the RHS of the reduced rule.
      Keep to zero when no symbol should be popped.  */
-  int yylen = 0;
-]b4_push_if([[
+  int yylen = 0;]b4_push_if([[
+
   if (!yyps->yynew)
     {
       yyn = yypact[yystate];
       goto yyread_pushed_token;
-    }]], [
-b4_initialize_parser_state_variables])[
+    }]])[
 
   YYDPRINTF ((stderr, "Starting parse\n"));
 
-- 
2.27.0