[patch/libiberty] IS_ABSOLUTE_PATH to handle both DOS and POS IX p ath styles

[Aleksandar Ristovski]

> Perhaps we should have a similar comment on the new ones, or at least
> a "see comment for ..."  comment.

Ok, here is the revised patch with more (hopefully clearer) comments and
full POSIX spelling.

Thank you,

Aleksandar Ristovski
QNX Software Systems

============================================================================


ChangeLog:
2008-01-04  Aleksandar Ristovski  <aristovski@qnx.com>

        * filenames.h (IS_DIR_SEPARATOR_DOS): New macro.
        (IS_ABSOLUTE_PATH_DOS): New macro.
        (IS_DIR_SEPARATOR_POSIX): New macro.
        (IS_ABSOLUTE_PATH_POSIX): New macro.
        (IS_DIR_SEPARATOR_ANY): New macro.
        (IS_ABSOLUTE_PATH_ANY): New macro.

Index: include/filenames.h
===================================================================
RCS file: /cvs/src/src/include/filenames.h,v
retrieving revision 1.4
diff -u -3 -p -r1.4 filenames.h
--- include/filenames.h	29 Mar 2007 21:03:43 -0000	1.4
+++ include/filenames.h	4 Jan 2008 21:06:09 -0000
@@ -26,6 +26,33 @@ Foundation, Inc., 51 Franklin Street - F
 #ifndef FILENAMES_H
 #define FILENAMES_H
 
+/* For DOS style paths.  */
+
+#define IS_DIR_SEPARATOR_DOS(c)	  ((c) == '/' || (c) == '\\')
+
+/*Note that IS_ABSOLUTE_PATH_DOS macro does not recognize
+  path starting with '/' as an absolute path. Otherwise, it behaves
+  as IS_DIR_SEPARATOR macro when configured for DOS-like
+  file system (see comment for IS_ABSOLUTE_PATH below).  */
+
+#define IS_ABSOLUTE_PATH_DOS(f)	  (((f)[0]) && ((f)[1] == ':'))
+
+/* For POSIX style paths.  */
+
+#define IS_DIR_SEPARATOR_POSIX(c)	  ((c) == '/')
+#define IS_ABSOLUTE_PATH_POSIX(f)	  (IS_DIR_SEPARATOR_POSIX((f)[0]))
+
+/* Universal macros, to be used on paths that could be either
+   POSIX or DOS. As a rule of thumb, these are the macros to be 
+   used when dealing with paths coming from/going to binaries, debug
+   info and such. When dealing with paths from the host filesystem (i.e.
+   paths from the filesystem where our application is running),
+   IS_ABSOLUTE_PATH should be used.  */
+
+#define IS_DIR_SEPARATOR_ANY(c)	  (IS_DIR_SEPARATOR_DOS(c))
+#define IS_ABSOLUTE_PATH_ANY(f)	  (IS_ABSOLUTE_PATH_POSIX(f) \
+				   || IS_ABSOLUTE_PATH_DOS(f))
+
 #if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined
(__CYGWIN__)
 
 #ifndef HAVE_DOS_BASED_FILE_SYSTEM