01-fyi-pure.patch

[Akim Demaille]

Index: ChangeLog
from  Akim Demaille  <address@hidden>
        
        Equip the skeleton chain with location tracking, runtime trace,
        pure parser and scanner.
        
        * src/parse-skel.y: Request a pure parser, locations, and prefix
        renaming.
        (%union): Having several members with the same type does not help
        type mismatches, simplify.
        (YYPRINT, yyprint): New.
        (yyerror): ``Rename'' (there is a #define yyerror skel_error) as...
        (skel_error): this.
        Handle locations.
        * src/scan-skel.l: Adjust to these changes.
        * src/skeleton.h (LOCATION_RESET, LOCATION_LINES, LOCATION_STEP)
        (LOCATION_PRINT, skel_control_t): New.
        
Index: src/parse-skel.y
--- src/parse-skel.y Sun, 30 Dec 2001 22:05:07 +0100 akim
+++ src/parse-skel.y Mon, 31 Dec 2001 11:56:34 +0100 akim
@@ -23,17 +23,25 @@
 %defines
 %verbose
 %error-verbose
+%locations
+%name-prefix="skel_"
+%pure-parser
 
 %{
 #include "system.h"
 #include "obstack.h"
+#include "quotearg.h"
 #include "files.h"
+#include "getargs.h"
 #include "output.h"
 #include "skeleton.h"
 #include "muscle_tab.h"
 
-extern FILE* yyin;
-extern int   yylineno;
+/* Pass the control structure to YYPARSE but not YYLEX (yet?). */
+#define YYPARSE_PARAM skel_control
+/* YYPARSE receives SKEL_CONTROL as a void *.  Provide a correctly
+   typed access to it.  */
+#define yycontrol ((skel_control_t *) skel_control)
 
 char* prefix = NULL;
 FILE* parser = NULL;
@@ -41,28 +49,37 @@
 size_t output_line;
 size_t skeleton_line;
 
-static int merror PARAMS ((const char* error));
-static int yyerror PARAMS ((const char* error));
+static void merror PARAMS ((const char* error));
 
+/* Request detailed parse error messages, and pass them to
+   YLEVAL_ERROR. */
+#undef  yyerror
+#define yyerror(Msg) \
+        skel_error (yycontrol, &yylloc, Msg)
+
+/* When debugging our pure parser, we want to see values and locations
+   of the tokens.  */
+#define YYPRINT(File, Type, Value) \
+        yyprint (File, &yylloc, Type, &Value)
+static void yyprint (FILE *file, const yyltype *loc,
+                     int type, const yystype *value);
 %}
 
 %union
 {
-  char *muscle;
   char *string;
-  char *literal;
   char character;
-  int yacc;
+  int  boolean;
 }
 
 /* Name of a muscle. */
-%token <muscle> MUSCLE
+%token <string> MUSCLE
 /* A string dedicated to Bison (%%"foo").  */
 %token <string> STRING
 /* Raw data, to output directly. */
-%token <literal> RAW
+%token <string> RAW
 /* Spaces. */
-%token <literal> BLANKS
+%token <string> BLANKS
 /* Raw data, but char by char. */
 %token <character> CHARACTER
 
@@ -76,11 +93,14 @@
 %token TOKENS
 %token ACTIONS
 
-%type <yacc> section.yacc
+%type <boolean> section.yacc
 
-%start skeleton
+%start input
 
 %%
+input:
+     { LOCATION_RESET (yylloc) } skeleton
+  ;
 
 skeleton : /* Empty.  */    { }
          | section skeleton { }
@@ -165,19 +185,53 @@
 }
 ;
 %%
+/*------------------------------------------------------------------.
+| When debugging the parser, display tokens' locations and values.  |
+`------------------------------------------------------------------*/
+
+static void
+yyprint (FILE *file,
+         const yyltype *loc, int type, const yystype *value)
+{
+  fputs (" (", file);
+  LOCATION_PRINT (file, *loc);
+  fputs (")", file);
+  switch (type)
+    {
+    case MUSCLE:
+    case STRING:
+    case RAW:
+    case BLANKS:
+      fprintf (file, " = %s", quotearg_style (c_quoting_style,
+                                             value->string));
+      break;
+
+    case CHARACTER:
+      fprintf (file, " = '%c'", value->character);
+      break;
+
+    case YACC:
+      fprintf (file, " = %s", value->boolean ? "true" : "false");
+      break;
+    }
+}
+
 
-static int
+static void
 merror (const char* error)
 {
   printf ("line %d: %%{%s} undeclared.\n", skeleton_line, error);
-  return 0;
 }
 
-static int
-yyerror (const char* error)
+void
+skel_error (skel_control_t *control,
+           const yyltype *loc, const char *msg)
 {
-  fprintf (stderr, "%s\n", error);
-  return 0;
+  /* Neutralize GCC warnings for unused parameters. */
+  skel_control_t *c = control;
+  c++;
+  LOCATION_PRINT (stderr, *loc);
+  fprintf (stderr, "%s\n", msg);
 }
 
 void
@@ -192,9 +246,10 @@
   skeleton_line = 1;
 
   /* Output.  */
-  yyin = fopen (skel, "r");
-  yydebug = 0;
-  yyparse ();
+  skel_in = fopen (skel, "r");
+  skel__flex_debug = 0;
+  skel_debug = trace_flag ? 1 : 0;
+  skel_parse (NULL);
 
   /* Close the last parser.  */
   if (parser)
Index: src/scan-skel.l
--- src/scan-skel.l Sun, 30 Dec 2001 22:05:07 +0100 akim
+++ src/scan-skel.l Mon, 31 Dec 2001 11:28:22 +0100 akim
@@ -19,14 +19,9 @@
    Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
    02111-1307, USA.  */
 
-%{
-#include "system.h"
-#include "skeleton.h"
-#include "parse-skel.h"
-%}
+%option debug nodefault noyywrap nounput
+%option prefix="skel_" outfile="lex.yy.c"
 
-%option nounput
-%option noyywrap
 /* If we enable
 
    %option yylineno
@@ -35,7 +30,22 @@
    Seems like a Flex bug to me: Why the heck yylineno would trigger
    the REJECT exception???  */
 
+%{
+#include "system.h"
+#include "skeleton.h"
+#include "parse-skel.h"
+%}
+
+%{
+/* Each time we match a string, move the end cursor to its end. */
+#define YY_USER_ACTION  yylloc->last_column += yyleng;
+%}
 %%
+%{
+  /* At each yylex invocation, mark the current position as the
+     start of the next token.  */
+  LOCATION_STEP (*yylloc);
+%}
 
 "%%{line}"          { return LINE; }
 "%%{skeleton-line}" { return SLINE; }
@@ -49,30 +59,37 @@
 
   /* Muscle.  */
 "%%{"[a-zA-Z][0-9a-zA-Z_-]+"}" {
-  yylval.muscle = xstrndup (yytext + 3, yyleng - 4);
+  yylval->string = xstrndup (yytext + 3, yyleng - 4);
   return MUSCLE;
 }
 
   /* String.  */
 "%%\"".*"\"" {
-  yylval.string = xstrndup (yytext + 3, yyleng - 4);
+  yylval->string = xstrndup (yytext + 3, yyleng - 4);
   return STRING;
 }
 
   /* End of line.  */
 "\n" {
+  LOCATION_LINES (*yylloc, yyleng);
   return '\n';
 }
 
   /* White spaces.  */
 [\t ]+ {
-  yylval.literal = yytext;
+  yylval->string = yytext;
   return BLANKS;
 }
 
+  /* Plain Characters.  */
+[^%\n]+ {
+  yylval->string = yytext;
+  return RAW;
+}
+
   /* Plain Character.  */
 . {
-  yylval.character = *yytext;
+  yylval->character = *yytext;
   return CHARACTER;
 }
 
Index: src/skeleton.h
--- src/skeleton.h Sun, 30 Dec 2001 21:07:37 +0100 akim
+++ src/skeleton.h Mon, 31 Dec 2001 11:19:09 +0100 akim
@@ -21,12 +21,56 @@
 #ifndef SKELETON_H_
 # define SKELETON_H_
 
-/* From parse-skel.y.  */
+# include "parse-skel.h"
+
+/* Initialize LOC. */
+# define LOCATION_RESET(Loc)                  \
+  (Loc).first_column = (Loc).first_line = 1;  \
+  (Loc).last_column =  (Loc).last_line = 1;
+
+/* Advance of NUM lines. */
+# define LOCATION_LINES(Loc, Num)             \
+  (Loc).last_column = 1;                      \
+  (Loc).last_line += Num;
+
+/* Restart: move the first cursor to the last position. */
+# define LOCATION_STEP(Loc)                   \
+  (Loc).first_column = (Loc).last_column;     \
+  (Loc).first_line = (Loc).last_line;
+
+/* Output LOC on the stream OUT. */
+# define LOCATION_PRINT(Out, Loc)                               \
+  if ((Loc).first_line != (Loc).last_line)                      \
+    fprintf (Out, "%d.%d-%d.%d",                                \
+             (Loc).first_line, (Loc).first_column,              \
+             (Loc).last_line, (Loc).last_column - 1);           \
+  else if ((Loc).first_column < (Loc).last_column - 1)          \
+    fprintf (Out, "%d.%d-%d", (Loc).first_line,                 \
+             (Loc).first_column, (Loc).last_column - 1);        \
+  else                                                          \
+    fprintf (Out, "%d.%d", (Loc).first_line, (Loc).first_column)
+
+
+/* Pure parsers need to pass arguments to yyparse. */
+typedef struct skel_control_s
+{
+  /* For the time being, nothing.  */
+} skel_control_t;
+
+/* From parse-skel.y. */
+extern int skel_debug;
+void skel_error PARAMS ((skel_control_t *control,
+                        const yyltype *loc, const char *msg));
 void process_skeleton PARAMS ((const char* skel));
 
 /* From scan-skel.l. */
+extern int skel__flex_debug;
+
+/* Renamed yyin. */
+extern FILE* skel_in;
+
 # define YY_DECL \
-  int yylex PARAMS ((void))
+  int skel_lex PARAMS ((yystype *yylval, yyltype *yylloc))
 YY_DECL;
 
 #endif SKELETON_H_