Re: header file guards conflict

[Akim Demaille]

Le 21 mai 2012 à 14:42, Akim Demaille a écrit :

> lalr1.cc: extract stack.hh.
>  To make merging easier in master.
> lalr1.cc: improve Doxygen documentation.
>  To include the prefix part in the \file directive.
> skeletons: remove support for unused directive.
>  Something that should never have been included.
> c++: compute the header guards.
>  Really compute the CPP guards.

This is the patch that really computes the header guards.

From eb76fadde9c5a3b23dc6761ddd4d267a6e7c3965 Mon Sep 17 00:00:00 2001
From: Akim Demaille <address@hidden>
Date: Mon, 21 May 2012 14:21:51 +0200
Subject: [PATCH 4/4] c++: compute the header guards.

This is a frequent request.  Recently pointed out by Wei Song,
<http://lists.gnu.org/archive/html/help-bison/2012-05/msg00002.html>.

* src/scan-skel.l (append_guard): New.
(@guard): New directive.
* data/lalr1.cc, data/location.cc, data/stack.hh: Use @guard for
these files.
* TODO (CPP Guard): Move to...
* NEWS: here.
Formatting changes.
---
 NEWS             |   32 +++++++++++++++++++++++++++-----
 THANKS           |    1 +
 TODO             |    4 ----
 data/lalr1.cc    |    7 +++----
 data/location.cc |   12 ++++++------
 data/stack.hh    |    6 +++---
 src/scan-skel.l  |   32 ++++++++++++++++++++++++++++++++
 7 files changed, 72 insertions(+), 22 deletions(-)

diff --git a/NEWS b/NEWS
index f554b9f..a8846a8 100644
--- a/NEWS
+++ b/NEWS
@@ -27,18 +27,40 @@ Bison News
   The Java parser no longer throws ArrayIndexOutOfBoundsException if
   the first token leads to a syntax error.  Some minor clean ups.
 
-** C++11 compatibility:
+** Changes for C++:
 
-  C and C++ parsers use nullptr instead of 0 when __cplusplus is
+*** C++11 compatibility:
+
+  C and C++ parsers use `nullptr' instead of `0' when __cplusplus is
   201103L or higher.
 
-** C++ locations:
+*** Header guards
+
+  The header files such as parser.hh, location.hh, etc. used a
+  constant name for preprocessor guards, for instance:
+
+  #ifndef BISON_LOCATION_HH
+  # define BISON_LOCATION_HH
+  ...
+  #endif // !BISON_LOCATION_HH
+
+  The inclusion guard is computed from `PREFIX/FILE-NAME', where lower
+  case characters are converted to upper case, and remaining
+  non-alphanumerical characters are converted to underscore.  With
+  `bison -o sub/parser.cc', location.hh would now include:
+
+  #ifndef YY_SUB_LOCATION_HH
+  # define YY_SUB_LOCATION_HH
+  ...
+  #endif // !YY_SUB_LOCATION_HH
+
+*** C++ locations:
 
   The position and location constructors (and their initialize
   methods) accept new arguments for line and column.  Several issues
   in the documentation were fixed.
 
-** liby is no longer asking for "rpl_fprintf" on some platforms.
+** liby is no longer asking for `rpl_fprintf' on some platforms.
 
 ** Changes in the manual:
 
@@ -77,7 +99,7 @@ Bison News
 
 *** The install-pdf target work properly:
 
-  Running "make install-pdf" (or -dvi, -html, -info, and -ps) no
+  Running `make install-pdf' (or -dvi, -html, -info, and -ps) no
   longer halts in the middle of its course.
 
 * Changes in version 2.5 (2011-05-14):
diff --git a/THANKS b/THANKS
index 6d0d89e..e3bf221 100644
--- a/THANKS
+++ b/THANKS
@@ -112,6 +112,7 @@ Tys Lefering              address@hidden
 Vin Shelton               address@hidden
 W.C.A. Wijngaards         address@hidden
 Wayne Green               address@hidden
+Wei Song                  address@hidden
 Wolfgang S. Kechel        address@hidden
 Wolfram Wagner            address@hidden
 Wwp                       address@hidden
diff --git a/TODO b/TODO
index d86d8d8..21ef4b9 100644
--- a/TODO
+++ b/TODO
@@ -125,10 +125,6 @@ we do the same in yacc.c.
 The code bw glr.c and yacc.c is really alike, we can certainly factor
 some parts.
 
-* Header guards
-
-From François: should we keep the directory part in the CPP guard?
-
 
 * Yacc.c: CPP Macros
 
diff --git a/data/lalr1.cc b/data/lalr1.cc
index 0fe3aee..ebfd4e1 100644
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -37,7 +37,6 @@ b4_defines_if(
 address@hidden(b4_spec_defines_file@)@
 b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++],
              [2002-2012])
-dnl FIXME: This is wrong, we want computed header guards.
 [
 /**
  ** \file ]b4_spec_defines_file[
@@ -46,8 +45,8 @@ dnl FIXME: This is wrong, we want computed header guards.
 
 /* C++ LALR(1) parser skeleton written by Akim Demaille.  */
 
-#ifndef PARSER_HEADER_H
-# define PARSER_HEADER_H
+#ifndef @guard(]b4_spec_defines_file[@)
+# define @guard(]b4_spec_defines_file[@)
 
 ]b4_percent_code_get([[requires]])[
 
@@ -286,7 +285,7 @@ b4_user_stype
 ])
 b4_percent_code_get([[provides]])[]dnl
 
-[#endif /* ! defined PARSER_HEADER_H */]
+[#endif // address@hidden(]b4_spec_defines_file[@)]
 ])dnl
 @output(b4_parser_file_name@)@
 b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++],
diff --git a/data/location.cc b/data/location.cc
index 0ee02c2..06ce604 100644
--- a/data/location.cc
+++ b/data/location.cc
@@ -27,8 +27,8 @@ b4_copyright([Positions for Bison parsers in C++],
  ** Define the ]b4_namespace_ref[::position class.
  */
 
-#ifndef BISON_POSITION_HH
-# define BISON_POSITION_HH
+#ifndef @guard(]b4_dir_prefix[position.hh@)
+# define @guard(]b4_dir_prefix[position.hh@)
 
 # include <iostream>
 # include <string>
@@ -148,7 +148,7 @@ b4_copyright([Positions for Bison parsers in C++],
   }
 
 ]b4_namespace_close[
-#endif // not BISON_POSITION_HH]
+#endif // address@hidden(]b4_dir_prefix[position.hh@)]
 @output(b4_dir_prefix[]location.hh@)@
 b4_copyright([Locations for Bison parsers in C++],
              [2002-2007, 2009-2012])[
@@ -158,8 +158,8 @@ b4_copyright([Locations for Bison parsers in C++],
  ** Define the ]b4_namespace_ref[::location class.
  */
 
-#ifndef BISON_LOCATION_HH
-# define BISON_LOCATION_HH
+#ifndef @guard(]b4_dir_prefix[location.hh@)
+# define @guard(]b4_dir_prefix[location.hh@)
 
 # include <iostream>
 # include <string>
@@ -295,6 +295,6 @@ b4_copyright([Locations for Bison parsers in C++],
 
 ]b4_namespace_close[
 
-#endif // not BISON_LOCATION_HH]
+#endif // address@hidden(]b4_dir_prefix[location.hh@)]
 m4_divert_pop(0)
 m4_changecom([#])
diff --git a/data/stack.hh b/data/stack.hh
index 5293377..912e4ba 100644
--- a/data/stack.hh
+++ b/data/stack.hh
@@ -30,8 +30,8 @@ b4_copyright([Stack handling for Bison parsers in C++],
  ** Define the ]b4_namespace_ref[::stack class.
  */
 
-#ifndef BISON_STACK_HH
-# define BISON_STACK_HH
+#ifndef @guard(]b4_dir_prefix[stack.hh@)
+# define @guard(]b4_dir_prefix[stack.hh@)
 
 # include <deque>
 
@@ -119,7 +119,7 @@ b4_copyright([Stack handling for Bison parsers in C++],
   };
 ]b4_namespace_close[
 
-#endif // not BISON_STACK_HH[]dnl
+#endif // address@hidden(]b4_dir_prefix[stack.hh@)[]dnl
 ]
 m4_divert_pop(0)
 m4_popdef([b4_copyright_years])dnl
diff --git a/src/scan-skel.l b/src/scan-skel.l
index 2433905..4b23d90 100644
--- a/src/scan-skel.l
+++ b/src/scan-skel.l
@@ -32,6 +32,7 @@
 #include <dirname.h>
 #include <error.h>
 #include <quotearg.h>
+#include <c-ctype.h>
 
 #include "complain.h"
 #include "getargs.h"
@@ -173,6 +174,20 @@ skel_scanner_free (void)
   yylex_destroy ();
 }
 
+/* Append SRC converted upper case alphanumeric or underscore to DST.
+   Return a pointer the next character in DST.  */
+static
+char *
+append_guard (char *dst, char const *src)
+{
+  for ( ; *src; ++dst, ++src)
+    *dst =
+      c_islower (*src) ? c_toupper (*src)
+      : c_isalnum (*src) ? *src
+      : '_';
+  return dst;
+}
+
 static void
 at_directive_perform (int at_directive_argc,
                       char *at_directive_argv[],
@@ -184,6 +199,23 @@ at_directive_perform (int at_directive_argc,
         fail_for_at_directive_too_many_args (at_directive_argv[0]);
       fputs (last_component (at_directive_argv[1]), yyout);
     }
+  else if (0 == strcmp (at_directive_argv[0], "@guard"))
+    {
+      if (at_directive_argc > 2)
+        fail_for_at_directive_too_many_args (at_directive_argv[0]);
+      else
+        {
+          char const *prefix = spec_name_prefix ? spec_name_prefix : "yy";
+          char const *arg = at_directive_argv[1];
+          char *guard = xmalloc (strlen (prefix) + 1 + strlen (arg) + 1);
+          char *cp = append_guard (guard, prefix);
+          *cp++ = '_';
+          cp = append_guard (cp, arg);
+          *cp = 0;
+          fputs (guard, yyout);
+          free (guard);
+        }
+    }
   else if (0 == strcmp (at_directive_argv[0], "@warn")
            || 0 == strcmp (at_directive_argv[0], "@complain")
            || 0 == strcmp (at_directive_argv[0], "@fatal"))
-- 
1.7.10.2