git/compat/vcbuild
Ramsay Jones b5d18b8e6f Fix the exit code of MSVC build scripts on cygwin
During an MSVC build on cygwin, the make program did not notice
when the compiler or linker exited with an error. This was caused
by the scripts exiting with the value returned by system() directly.

On POSIX-like systems, such as cygwin, the return value of system()
has the exit code of the executed command encoded in the first byte
(ie the value is shifted up by 8 bits). This allows the bottom
7 bits to contain the signal number of a terminated process, while
the eighth bit indicates whether a core-dump was produced. (A value
of -1 indicates that the command failed to execute.)

The make program, however, expects the exit code to be encoded in the
bottom byte. Futhermore, it apparently masks off and ignores anything
in the upper bytes.

However, these scripts are (naturally) intended to be used on the
windows platform, where we can not assume POSIX-like semantics from
a perl implementation (eg ActiveState). So, in general, we can not
assume that shifting the return value right by eight will get us
the exit code.

In order to improve portability, we assume that a zero return from
system() indicates success, whereas anything else indicates failure.
Since we don't need to know the exact exit code from the compiler
or linker, we simply exit with 0 (success) or 1 (failure).

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-10-08 22:53:12 -07:00
..
include Add MinGW header files to build git with MSVC 2009-09-18 20:00:42 -07:00
scripts Fix the exit code of MSVC build scripts on cygwin 2009-10-08 22:53:12 -07:00
README Add scripts to generate projects for other buildsystems (MSVC vcproj, QMake) 2009-09-18 20:00:42 -07:00

The Steps of Build Git with VS2008

1. You need the build environment, which contains the Git dependencies
   to be able to compile, link and run Git with MSVC.

   You can either use the binary repository:

       WWW: http://repo.or.cz/w/msvcgit.git
       Git: git clone git://repo.or.cz/msvcgit.git
       Zip: http://repo.or.cz/w/msvcgit.git?a=snapshot;h=master;sf=zip

   and call the setup_32bit_env.cmd batch script before compiling Git,
   (see repo/package README for details), or the source repository:

       WWW: http://repo.or.cz/w/gitbuild.git
       Git: git clone git://repo.or.cz/gitbuild.git
       Zip: (None, as it's a project with submodules)

   and build the support libs as instructed in that repo/package.

2. Ensure you have the msysgit environment in your path, so you have
   GNU Make, bash and perl available.

       WWW: http://repo.or.cz/w/msysgit.git
       Git: git clone git://repo.or.cz/msysgit.git
       Zip: http://repo.or.cz/w/msysgit.git?a=snapshot;h=master;sf=zip

   This environment is also needed when you use the resulting
   executables, since Git might need to run scripts which are part of
   the git operations.

3. Inside Git's directory run the command:
       make common-cmds.h
   to generate the common-cmds.h file needed to compile git.

4. Then either build Git with the GNU Make Makefile in the Git projects
   root
       make MSVC=1
   or generate Visual Studio solution/projects (.sln/.vcproj) with the
   command
       perl contrib/buildsystems/generate -g Vcproj
   and open and build the solution with the IDE
       devenv git.sln /useenv
   or build with the IDE build engine directly from the command line
       devenv git.sln /useenv /build "Release|Win32"
   The /useenv option is required, so Visual Studio picks up the
   environment variables for the support libraries required to build
   Git, which you set up in step 1.

Done!