Re: Caret escaping

[Alessandro Vesely]

Markus Mauhart wrote:
> > %% Alessandro Vesely <address@hidden> writes:
> >
> > av> Thus, in case the "slow path" is taken, the LINE command should be replaced 
> > with
> > av> SHELL FLAG ESCAPED-LINE, where:
> > av>   SHELL may be either a unixy_shell, cmd.exe or the old command.com,
> > av>   FLAG should be -c for unixy_shell or /C otherwise, and
> > av>   ESCAPED-LINE should be escaped using backslashes for unixy_shell,
> > av>     carets for cmd.exe, or
> > av>     no escape at all for the old command.exe.
> > av> Then there is a batch_mode_shell flag, which is usually set for cmd.exe
> > av> and causes a NOT-SO-ESCAPED-LINE to be written to a temporary batch file.
> > av> Should we revise those specs in order to make a smarter use of cmd.exe?
>
> I just checked it out (VC - built make381beta4 with above patches applied)
> and it turns out that ^-escaping breaks my makefiles (not using -j):
> make381beta4.exe now creates a batch file which 2nd line starts with ...
>
>     (^"C:/Program Files/msvs71/Common7/Tools/vsvars32.bat^" > nul) && cl
> [...]
>
> So AFAICS this part of the jobs-patch is wrong:
>
>     >  . use '^' to escape special characters such as \ and " in job.c

Thanks for the test. You proved that making a smarter use of cmd.exe is
not strightforward. cmd.exe /C LINE does not require LINE to be a single
argument, i.e. double quotes around LINE are not needed.

The special characters are &<>()@^| thus \ and " should not be escaped.

The following command works as intended from the command line:

 start cmd.exe /C "("C:/Program Files/msvs71/Common7/Tools/vsvars32.bat" > nul)" 
^&^& cl

Thus, the escaping logic used by cmd.exe is not consistent with Unix,
and there is no code in make that would produce the above escaping.