https://issues.dlang.org/show_bug.cgi?id=24315

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
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                 CC|                            |ibuclaw@gdcproject.org

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https://issues.dlang.org/show_bug.cgi?id=24315

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
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           Severity|normal                      |regression

--- Comment #1 from Iain Buclaw <ibuclaw@gdcproject.org> ---
This is a regression.

github.com/dlang/dmd/pull/15981

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https://issues.dlang.org/show_bug.cgi?id=24315

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
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           Keywords|                            |ImportC
                 CC|                            |bugzilla@digitalmars.com

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https://issues.dlang.org/show_bug.cgi?id=24315

--- Comment #2 from Walter Bright <bugzilla@digitalmars.com> ---
The problem with using mkstemp() is it returns a file descriptor. I need it to
return a file name.

Any way the warning can be turned off?

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https://issues.dlang.org/show_bug.cgi?id=24315

--- Comment #3 from Walter Bright <bugzilla@digitalmars.com> ---
Maybe I just need to write our own tmpnam() function.

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https://issues.dlang.org/show_bug.cgi?id=24315

kdevel <kdevel@vogtner.de> changed:

           What    |Removed                     |Added
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                 CC|                            |kdevel@vogtner.de

--- Comment #4 from kdevel <kdevel@vogtner.de> ---
(In reply to Walter Bright from comment #2)
> The problem with using mkstemp() is it returns a file descriptor. I need it
> to return a file name.

It returns the file name, too: [1] [2] [3] [4]

[1] https://pubs.opengroup.org/onlinepubs/009604499/functions/mkstemp.html
"The string in template should look like a filename with six trailing 'X' s;
mkstemp() replaces each 'X' with a character from the portable filename
character set."
[2]
https://forum.dlang.org/post/mailman.4798.1421530338.9932.digitalmars-d-learn@puremagic.com
"Getting a safe path for a temporary file"
[3]
https://forum.dlang.org/post/mailman.667.1343269970.31962.digitalmars-d@puremagic.com
"temporary files - what is the resolution?"
[4] https://www.gnu.org/software/gnulib/manual/html_node/mkstemp.html

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https://issues.dlang.org/show_bug.cgi?id=24315

--- Comment #5 from Walter Bright <bugzilla@digitalmars.com> ---
It returns a file descriptor for an already opened file.

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https://issues.dlang.org/show_bug.cgi?id=24315

--- Comment #6 from kdevel <kdevel@vogtner.de> ---
(In reply to Walter Bright from comment #5)
> It returns a file descriptor for an already opened file.

The descriptor is unused and can be safely closed (or the FILE* ptr fclosed after using fdopen). Using mkstemp is how to create a named temporary file lege artis in GNU/Linux [5].

The actual filename is in the writable template-buffer given as parameter to mkstemp. The preprocessor will put its output into that file.

I was under the impression that not the POSIX but the Windows version could
pose
problems here?

[5] sec 2.2.2. (p. 7) of Ulrich Drepper: Defensive Programming for Red Hat
    Enterprise Linux (and What To Do If Something Goes Wrong)
    http://people.redhat.com/drepper/defprogramming.pdf

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https://issues.dlang.org/show_bug.cgi?id=24315

--- Comment #7 from Iain Buclaw <ibuclaw@gdcproject.org> ---
(In reply to Walter Bright from comment #5)
> It returns a file descriptor for an already opened file.
The passed string is an out parameter as well.

@kdevel one convenience of tmpnam is that you don't have to worry about where the $TEMP directory is located for the vagary of supported platforms.

> Maybe I just need to write our own tmpnam() function.
The generic-ish implementation should be simple enough, could return a slice too instead of a pointer.

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https://issues.dlang.org/show_bug.cgi?id=24315

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
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            Summary|dmd/cpreprocess.d:87:       |dmd/cpreprocess.d:87:
                   |warning: the use of         |warning: use of tmpnam is
                   |`tmpnam' is dangerous,      |dangerous use mkstemp
                   |better use `mkstemp'        |

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