Date: Tue, 6 Jul 2010 14:11:02 +0200
From: Robert Schiele <rschiele@gmail.com>
To: cygwin@cygwin.com
Subject: weird behavior regarding case sensitivity of GNU make's $(wildcard) function
Message-ID: <20100706121100.GA19706@sigfpe.ibm.com>
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Hi!

I found the following (in my optinion weird) behavior of the $(wildcard)
function of GNU make when running on Cygwin:

I have a place in a makefile that checks for existence of a file (let's call
it "/cygdrive/c/path/to/file") with $(wildcard /cygdrive/c/path/to/file).
Unfortunately the vendor of this file refers to this file with different case
letters than it is materialized on disk.  On the disk the file is actually
stored as "C:\Path\to\File" which translates to the Cygwin style name
"/cygdrive/c/Path/to/File".  Since Windows is supposed to be case-insensitive
this should be fine but in Cygwin's GNU make binary (current version as of
today) I observed the following behavior:

1. "$(wildcard /cygdrive/c/path/to/file)" does not match anything and thus
   returns an empty string.

2. "$(wildcard /cygdrive/c/Path/to/File)" does match the file and thus returns
   "/cygdrive/c/Path/to/File" as expected.

3. "$(wildcard /cygdrive/c/Path/to/file)" does not match anything and thus
   returns an empty string.

4. "$(wildcard /cygdrive/c/path/to/File)" does match the file and thus returns
   "/cygdrive/c/path/to/File".

More generic inspection reveals that apparently the $(wildcard) function seems
to be case-insensitive on the directory part but case-sensitive on the file
name part of the absolute path given.

Is this kind of expected behavior or does this point to a bug in the GNU make
implementation (or even further down in a Cygwin library)?

Does anyone know of a reasonable workaround?  Is there a way to make the
$(wildcard) function case-insensitive completely (like by setting a special
option of flag)?  Or is there probably a better replacement function that does
basically the same but in a case-insensitive way?

If this doesn't work is there probably some function that converts filename
strings to a representation that is exactly how a file is stored on the disk,
i.e. I give it "/cygdrive/c/path/to/file" and it returns
"/cygdrive/c/Path/to/File"?

Any better ideas?

Robert

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