Re: Import include/filenames.h from BFD (Windows/DJGPP testers needed)

[Danny Smith <danny_r_smith_2001 at yahoo dot co dot nz>]

Zack Weinberg wrote:

> FYI, I have checked in include/filenames.h, which cannot break
> anything by its mere presence.  I am still looking for testers
> for the gcc part of the patch.
> 
> zw
> 


I've tested your patch with mingw32 bootstrap (c,c++ only) and no problems
on NT operating systems.  However, I expect there will be problems on Win9x
and WinMe because of differences in handling of '/' vs '\\' and the
reversal of DIR_SEPARATOR and DIR_SEPARATOR_2 for mingw32.

I tried that reversal in mingw distros of gcc before and got heaps of bug
reports. This is why:

On NT '/' and '\\' can be used interchangeably in CreateProcess, the
win32 API function that handles spawn* and exec* families of functions.
>From what I've found out through trial-and-error: On Win9x and WinME,
they can be used interchangeably _iff_ the first element of the
argument vector (the pathname of the executable) is _not_ quoted. If it
is quoted, the use of '/' causes problems. (I don't know why: maybe is
has something to do the use of /c etc as switches in the command /c syntax).
Now, libiberty's pexecute takes great care to ensure that the argument
is quoted. Why? Because windows encourages users to put spaces in their
filenames and without quotes
C:/Program Files/mingw/bin/gcc.exe
is treated as two strings. You can't win.

When we compile gcc -v foo.c, the behaviour with your patch is:

gcc version 3.4 20030701 (experimental)
 D:/MINGW/BIN/../lib/gcc-lib/mingw32/3.4/cc1.exe -quiet -v -iprefix
D:\MINGW\BIN/../lib/gcc-lib/mingw32/3.4/ foo.c -quiet -dumpbase foo.c -auxbase foo -version -o
D:\TEMP/cc9daaaa.s
#include "..." search starts here:
#include <...> search starts here:
 D:/MINGW/include
 D:/MINGW/lib/gcc-lib/mingw32/3.4/include
 D:/MINGW/mingw32/include
 /mingw/include
 /mingw/include
 /mingw/lib/gcc-lib/mingw32/3.4/include
 /mingw/mingw32/include
 /mingw/include
End of search list.
GNU C version 3.4 20030701 (experimental) (mingw32)
	compiled by GNU C version 3.4 20030701 (experimental).
GGC heuristics: --param ggc-min-expand=34 --param ggc-min-heapsize=8118
 D:/MINGW/BIN/../lib/gcc-lib/mingw32/3.4/../../../../mingw32/bin/as.exe
...
etc
 

This works fine on NT.  On Win9X, it won't because of the passing of the
the first element of the argument vector  like

"D:/MINGW/BIN/../lib/gcc-lib/mingw32/3.4/cc1.exe"

through spawnv

I'd like to have the primary DIR_SEPARATOR as '/' rather '\\' because
having '/' simplifies generating dependencies (some versions of make
have problems with '\\'). Also when using gcc -v in configure scripts,
having everyting in standard form simplifies the detection of ld and as
paths. Finally, using '\\' as DIR_SEPARATOR used to tweak a preprocessor
bug in C++ code where a '\\' in __FILE__ was sometimes treated like a
line-continuation. That bug is gone now, but.

FWIW, the only place that I've seen  '/' as DIR_SEPARATOR causing problems
on Win9x is in gcc.c's execute().

The following patch to libiberty/pex-win32.c, combined with your patch,
causes no regression on NT and should allow #define DIR_SEPARATOR '/' to
work on Win9x. Unfortunately, I no longer have access to Win9x to test
properly. Can someone help?

Danny

Changelog

2003-07-03  Danny Smith  <dannysmith@users.sourceforge.net>

	* pex-win32.c (fix_argv): Ensure that the executable pathname
	uses Win32 backslashes.
	(pexecute): Cast away constness when assigning *errmsg_arg.

Index: pex-win32.c
===================================================================
RCS file: /cvs/gcc/gcc/libiberty/pex-win32.c,v
retrieving revision 1.1
diff -c -3 -p -r1.1 pex-win32.c
*** pex-win32.c	24 Jan 2003 20:02:11 -0000	1.1
--- pex-win32.c	2 Jul 2003 21:38:41 -0000
*************** fix_argv (argvec)
*** 57,63 ****
--- 57,69 ----
       char **argvec;
  {
    int i;
+   char * command0 = argvec[0];
  
+   /* Ensure that the executable pathname uses Win32 backslashes.  */
+   for (; *command0 != '\0'; command0++)
+     if (*command0 == '/')
+       *command0 = '\\';
+  
    for (i = 1; argvec[i] != 0; i++)
      {
        int len, j;
*************** pexecute (program, argv, this_pname, tem
*** 203,209 ****
    if (pid == -1)
      {
        *errmsg_fmt = install_error_msg;
!       *errmsg_arg = program;
        return -1;
      }
  
--- 209,215 ----
    if (pid == -1)
      {
        *errmsg_fmt = install_error_msg;
!       *errmsg_arg = (char*) program;
        return -1;
      }
  

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