Fix Win32 build with new .def files and DLL_IMP_EXP ...

[bacula/bacula] / bacula / src / win32 / README.mingw32

Instructions to build Bacula using the MinGW32 on Linux
=======================================================

This file documents the tools (scripts) we use for building Bacula for
Microsoft Windows using the cross-compiler tools on a Linux system.  We
use Fedora Core 5 and SuSE so those should definitely work.  But there
shouldn't be any issues on other Linux distributions.

We don't officially support this script, but it is what we use, and it should
build on any Linux machine if you carefully follow the instructions and have
all the prerequisite programs loaded on your machine.

It has also been tested on other systems such as FreeBSD and CentOS.  We
expect that there may be problems on systems other than Linux where you
are pretty much on your own.  However, we will try to provide responses to
your questions on the bacula-devel list, but we can't guarantee anything.

Directory Structure
=====================
The new directory structure is:

  bacula-top                 Top level directory -- any name
    bacula                   Top level Bacula source directory -- any name
      src
        win32                Main directory where Windows version is built.

    docs                     Top level Bacula documentation directory

    depkgs-mingw32 (MinGW32) 3rd Party Dependencies for MinGW32 build
or
    depkgs-msvc (MS VC++)    3rd Party Dependencies for Microsoft VC++ build.
      bin              --
      include            |
      lib                |
      man                |   Created by script
      nsis               |-- .../bacula/src/win32/build-depkgs-mingw32
      scons              |
      share              |
      src                |
      ssl              --
      vss
        inc                  A copy of the Windows VSS/inc directory

    cross-tools (MinGW32)    Cross compilation tools (gcc, g++, mingw32, ...)
      binutils-mingw32 --
      gcc-mingw32        |   Created by script
      mingw32            |-- .../bacula/src/win32/build-win32-cross-tools
      mingw-utils        |
      source           --


One-time Setup
==============

If you're reading this file you've probably already enlisted in the SVN tree or
extracted the contents of the source tar.  If not you need to do that first.

You also need to download one of the doc tar balls and extract to your
top level Bacula directory.  It is referred to as bacula-top in the
diagram located in README.win32.  It will be signified in this file as ...

The extracted doc directory name will be bacula-docs-version where version
is the version number.  The directory must be renamed to docs (ie remove
the leading bacula- and the -version portion of the name).

Note, a number of packages must be installed to build the cross-tools
and the depkgs files.  Most are rather standard such as gcc, g++,
make, ...  However a few that you may not have are:

  texinfo
  flex
  bison
  patch (Debian)
  m4
  postgresql (at least client)
  mysql (at least client)
  SQLite3 (from depkgs or as package)
  ...

Once the source is on your system, change to the win32 directory
        cd .../bacula/src/win32

Download and build the cross compiler tools
        ./build-win32-cross-tools

Download and build the 3rd party dependencies
        ./build-depkgs-mingw32

Note, that during the build process you will see a moderate amount of
output. If something fails, it is probably because you don't have one
of the build dependencies (hopefully all mentioned above) loaded on your  
system. To find out what is going wrong, do the following:

  cd .../depkgs-mingw32/src/<package-name>
   
where <package-name> is where the package is unpacked and built. Normally
it is relatively obvious when looking at the src directory.             

In that directory, you should find a make.log, which has the full details
of the compiles, links, and installs done for that package.

Note, if you are building on a 64 bit machine, please know that
the build for the depkgs-mingw32/scons puts the python scons libraries
in depkgs-mingw32/scons/lib64 but when running scons it looks for the
libs in depkgs-mingw32/scons/lib. So adding symlink from
depkgs-mingw32/scons/lib64 to depkgs-mingw32/scons/lib will fix the
problem.

You need the header files from the Microsoft VSS SDK.  Unfortunately the SDK
can only be downloaded and installed on a Windows system.  You can find it on
Microsoft's web-site at:

http://www.microsoft.com/downloads/details.aspx?FamilyID=0b4f56e4-0ccc-4626-826a-ed2c4c95c871&DisplayLang=en

If that link doesn't work then go to http://www.microsoft.com and search for

        "download volume shadow copy service sdk"

we are currently using version 7.2 released 8/3/2005.

Normally the files will be installed in:

        c:\Program Files\Microsoft\VSSSDK72

You only need to copy everything under the c:\Program Files\Microsoft\VSSSDK72\inc
directory into .../depkgs-mingw32/vss/inc.  In doing so, please ensure that
the case in maintained on the directory and filenames -- some contain uppercase 
characters !!!

The above only needs to be done once unless we change the cross-tools
or the dependencies versions.  In general, you can run the script multiple
times with no problem.  For it to work, you must have at a minimum the
following:

        gcc
        g++
        wget
        texinfo
        bison
        flex

and possibly other packages.


Building
========

Finally, to build the Microsoft Windows version of Bacula, do the following:

   cd .../bacula/src/win32
   make

If all goes well, you will end with all the executables in the
.../bacula/src/win32/release directory.

If you have an older build environment, you might do the following
to ensure that you pick up all the new Win32 changes:

   cd .../bacula
   make clean
   svn update
   cd src/win32
   make

The installer is now built as part of the default rule when you
say "make" in the src/win32 directory.


Updating the 3rd party package patches
======================================

If one of the patches changes in .../bacula/src/win32/patches, you will
need to update the corresponding dependency.  You can install new patches
by doing the following (we assume the patch in question is for openssl).

   cd .../bacula/src/win32
   ./build-depkgs-mingw32 -C openssl

NOTE: The -C means clobber.  Any local changes to the source code in
      the .../depkgs-mingw32/src directory will be lost.  The source
      will be reextracted from the archive and the current patches
      will be applied.


Adding a new global function or global data
===========================================

bacula.dll
----------

The code from the following directories is built into bacula.dll:

   .../bacula/src/lib
   .../bacula/src/libfind
   .../bacula/src/win32/compat

A new function or data variable which must be accessed from outside
of bacula.dll requires special treatment.  It must be specifically
exported.

New data variables are exported by adding the macro DLL_IMP_EXP to
the variable declaration in the header file.  All exported variables
must be declared in a header file and MUST NOT be declared in a
source file referencing the variable. Example, src/lib/runscript.h:

extern DLL_IMP_EXP bool (*console_command)(JCR *jcr, const char *cmd);

or src/jcr.h

extern int DLL_IMP_EXP num_jobs_run;
extern DLL_IMP_EXP dlist * last_jobs;
...


Exporting functions is now more or less automated.  If you find that
a function name has been added, changed, or an argument modified,    
simply do the following:

   cd .../bacula/src/win32/dll 
   make                  (to build the .o files, note the link will fail)
   ./make_def >bacula.def

This should rebuild the bacula.def file, but it uses relative paths
and assumes you have the directory structure noted above. If you 
are using something different, you can set the NM variable at the
top of the make_def file to use an absolute path to the correct
directory.

===== manual changing of bacula.def no longer necessary =====
If you want to do it manually, please see below:
Exporting a function requires a bit more work.  You must determine the
C++ mangled name of the new function.

   strings .../bacula/src/win32/dll/<file>.o | grep <symbol>

Note, strings often will not show the desired symbol. In that case,
use:
   
   nm .../bacula/src/win32/dll/<file>.o

Replace <file> with the base part of the name of the source code file
which contains the new function.  Replace <symbol> with the name of
the new function.  Remove the leading underscore and place the result
in the file

   .../bacula/src/win32/dll/bacula.def
=== end manual changing of bacula.def ==========

If you add a new file, you will need to specify its name in

   .../bacula/src/win32/dll/Makefile
and
   .../bacula/src/win32/libbac/Makefile

bacula_cats.dll
---------------

The code from the .../bacula/src/cats directory is built into database
provider specific libraries of the form cats_<db>.dll.

The database specific portion <db> is mysql for MySQL, pgsql for
PostgreSQL, sqlite for SQLite, and bdb for the built-in Bacula database.

During installation of the Director, one of the database libraries is
copied to the system and renamed bacula_cats.dll.

A new function or data variable which must be accessed from outside
of bacula_cats.dll requires special treatment.  It must be specifically
exported.

New data variables are exported by placing their name in the file
.../bacula/src/win32/cats/bacula_cats.def.

As with the bacula.def file above, this is now more or less automated.
When the link dies, simply do the following:

   cd .../bacula/src/win32
   make                  (to build the .o files, note the link will fail)
   cd cats
   ./make_def >bacula_cats.def

This should rebuild the bacula_cats.def file. Note, if you have
changed any data entry points, you will need to modify the make_def
script -- it should be rather obvious.


===== manual changing of bacula_cats.def no longer necessary =====
Exporting a function requires a bit more work.  You must determine the
C++ mangled name of the new function.

   strings .../bacula/src/win32/cats/cats_*/<file>.o | grep <symbol>

Note, strings often will not show the desired symbol. In that case,
use:

   nm .../bacula/src/win32/dll/<file>.o

Replace <file> with the base part of the name of the source code file
which contains the new function.  Replace <symbol> with the name of
the new function.  Remove the leading underscore and place the result
in the .../bacula/src/win32/cats/bacula_cats.def file.
=== end manual changing of bacula_cats.def ==========


Structure of the MinGW32 build environment
==========================================

The basic strategy is each Makefile in the various subdirectories includes
Makefile.inc, defines variables and rules specific to what is being built,
then includes Makefile.rules which defines all the rules.

Makefile.inc defines the locations of all the dependencies and the compiler
and linker flags.  It is automatically created from Makefile.inc.in.  Any
changes must be made to Makefile.inc.in not Makefile.inc or they will be
overwritten the next time Makefile.inc.in is updated.

Makefile.rules defines a bunch of macros to simplify building.  It also
includes all the basic rules for building objects, GUI and console
executables, etc.

Makefile.template is a template for creating new Makefiles, if you are
creating a new directory, copy Makefile.template to Makefile in that
directory and edit to suit.