[patch] __TIMESTAMP__ predefined macro

[Andrew Pinski]

> Hi!
> 
> The patch implements __TIMESTAMP__ predefined macro in the form similar 
> to MSVC and ICC compilers - date and time of the last modification of 
> the current source file like "Thu Feb  9 18:07:36 2006". This macro 
> seems to be widely used but not implemented in GCC yet.
> 
> Verified at x86_64-redhat-linux-gnu.
> 
> Ok for mainline?
> 
> - Grigory
> 
> 2006-02-15  Grigory Zagorodnev <grigory_zagorodnev@linux.intel.com>
> 
>      * gcc/doc/cpp.texi: add description of __TIMESTAMP__ macro to the 
> user's documentation
>      * gcc/testsuite/gcc.dg/cpp/undef2.c: enlarge tests to cover new 
> predefined macro
>      * gcc/testsuite/gcc.dg/cpp/trad/builtins.c: same as above
>      * libcpp/macro.c (_cpp_builtin_macro_text): generate text for 
> __TIMESTAMP__ built-in macro
>      * libcpp/files.c (_cpp_get_file_stat): new function - interface to 
> file statistics record in _cpp_file structure.
>      * libcpp/include/cpplib.h: new constant to process __TIMESTAMP__ 
> macro definition
>      * libcpp/init.c: new built in macro definition
>      * libcpp/internal.h: new declaration of _cpp_get_file_stat; new 
> field timestamp of cpp_buffer structure to hold generated string for 
> future possible reuse

It would be better if you added new testcases instead of modifying the ones already
there so it is easier to compare results between GCC versions.

A better way to write this changeLog is:

gcc/ChangeLog:
	* doc/cpp.texi (__TIMESTAMP__): Document.

libcpp/ChangeLog:
	* macro.c (_cpp_builtin_macro_text): Handle BT_TIMESTAMP.
	* files.c (_cpp_get_file_stat): New function.
	* include/cpplib.h (builtin_type): Add BT_TIMESTAMP.
	* init.c (builtin_array): Add support for __TIMESTAMP__/BT_TIMESTAMP.
	* internal.h (_cpp_get_file_stat): Prototype.
	(struct cpp_buffer): Add timestamp.

Some comments about the patch:
+	        struct stat *st = _cpp_get_file_stat(file);
+	        if (st)
+	            tb = localtime (&(st->st_mtime));

Why not make a function which returns a pointer to the modification date instead of returning one
to the stat?

+	            sprintf ((char *)pbuffer->timestamp, 
+			        "\"%3s %3s %2d %02d:%02d:%02d %4d\"",
+			        daynames[tb->tm_wday], monthnames[tb->tm_mon], 
+			        tb->tm_mday, tb->tm_hour, tb->tm_min, 
+			        tb->tm_sec, tb->tm_year + 1900);


Also why don't you just use ctime or asctime instead of spelling it out?
Considering ctime and asctim are C89, I would expect most targets to define it anyways.

Thanks,
Andrew Pinski