Packaging Guidelines for MinGW Windows cross-compiler
Please note this is a draft. "Rationale" sections are for discussion and will be deleted from the final document.
Naming
Packages should be named by prefixing the upstream package name
with mingw-
Rationale Debian name their packages mingw32-*
.
However I can't see a reason for including '32' in the name, particularly
since (a) the upstream package is just called mingw and (b)
we may want to build 64 bit binaries.
Base packages
The base packages provide a root filesystem, base libraries,
binutils (basic programs like 'strip', 'ld' etc), the compiler (gcc)
and the Win32 API. Packages may need to depend on one or more of
these. In particular, almost any conceivable package should
depend on mingw-runtime
.
mingw-filesystem |
Core filesystem directory layout, and RPM macros for spec files. Equivalent to 'filesystem' RPM |
mingw-runtime |
Base libraries for core MinGW runtime & development environment. Equivalent to 'glibc' RPM |
mingw-binutils |
Cross-compiled binutils (utilities like 'strip', 'as', 'ld') which
understand Windows executables and DLLs. Equivalent to 'binutils' RPM |
mingw-w32api |
Win32 API. A free (public domain) reimplementation of the header files required to link to the Win32 API. No direct equivalent in base Fedora - 'glibc' is closest |
mingw-gcc |
GNU compiler collection. Compilers for C and C++ which cross-compile to a Windows target. Equivalent to 'gcc' RPM |
Rationale I've used the same names as the upstream packages, and also the same names as Debian (minus the unnecessary '32' which Debian has in the name).
Filesystem layout
[root] | +- etc | | | +- rpm | | | +- macros.mingw | +- usr | +- bin - Links to cross compiler toolchain | | | +- i686-pc-mingw-cpp | +- i686-pc-mingw-gcc | +- i686-pc-mingw-g++ | +- ... etc.. | +- lib | | | +- rpm | | | +- mingw-defs - custom helper scripts for auto-requires, binary stripping, etc | +- mingw-find-provides.sh - extra DLL names | +- mingw-find-requires.sh - discover required DLL names | +- i686-pc-mingw - root of mingw toolchain and binaryes - see next diagram
[mingw-root] | +- bin - Cross compiler toolchain | | | +- cpp | +- gcc | +- g++ | +- ... etc ... | +- lib - Cross compiler toolchain support libraries / files | +- sys-root - root for cross compiled binaries | +- mingw | +- bin - cross-compiled binaries & runtime DLL parts +- doc - documentation +- include - include files for cross compiled libs +- lib - cross-compiled static libraries & linktime DLL parts | | | +- pkgconfig - pkg-config definitions for libraries | +- share | +- man
Standard mingw RPM macros
The mingw-filesystem
package provides a number of convenience macros for the cross compiled sysroot directories, and toolchain. It is mandatory to use these macros in all mingw packages submitted to Fedora.
Toolchain macros
The following macros are for the %build and %install section of the spec
_mingw_ar | i686-pc-mingw32-ar | cross compiler 'ar' binary |
_mingw_cc | i686-pc-mingw32-gcc | cross compiler 'gcc' binary |
_mingw_cflags | -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions --param=ssp-buffer-size=4 -I%{_mingw_includedir} | Rationale: we need to remove the -m64 flag from standar RPM_OPTS_FLAGS |
_mingw_configure | CC="%{_mingw_cc}" CFLAGS="%{_mingw_cflags}" ./configure --build=%_build --host=%{_mingw_host} --target=%{_mingw_target} --prefix=%{_mingw_prefix} | standard invocation for autotools 'configure' scripts |
_mingw_cpp | i686-pc-mingw32-gcc -E | cross compiler 'cpp' binary |
_mingw_host | i686-pc-mingw32 | Host platform for build |
_mingw_objdump | i686-pc-mingw32-objdump | cross compiler 'objdump' binary |
_mingw_ranlib | i686-pc-mingw32-ranlib | cross compiler 'ranlib' binary |
_mingw_strip | i686-pc-mingw32-strip | cross compiler 'strip' binary |
_mingw_target | i686-pc-mingw32 | Target platform for build |
Filesystem location macros
The following macros are for use in %build, %install and %files sections of the RPM spec
_mingw_bindir | %{_mingw_prefix}/bin |
_mingw_datadir | %{_mingw_prefix}/share |
_mingw_docdir | %{_mingw_prefix}/share/doc |
_mingw_includedir | %{_mingw_prefix}/include |
_mingw_libdir | %{_mingw_prefix}/lib |
_mingw_libexecdir | %{_mingw_prefix}/libexec |
_mingw_mandir | %{_mingw_prefix}/share/man |
_mingw_prefix | %{_mingw_sysroot}/mingw |
_mingw_sbindir | %{_mingw_prefix}/sbin |
_mingw_sysconfdir | %{_mingw_prefix}/etc |
_mingw_sysroot | %{_prefix}/i686-pc-mingw32/sys-root |
Naming of the cross-compilers and binutils
The cross-compilers and binutils are Fedora binaries and are therefore placed in %{_bindir}
(ie. /usr/bin
) according to the FHS and Fedora guidelines.
The cross-compilers and binutils which generate i686 binaries for Windows are named:
%{_bindir}/i686-pc-mingw32-gcc %{_bindir}/i686-pc-mingw32-g++ %{_bindir}/i686-pc-mingw32-ld %{_bindir}/i686-pc-mingw32-as %{_bindir}/i686-pc-mingw32-strip etc.
The same binaries are present in %{_prefix}/i686-pc-mingw32/bin
without any prefix in the name, ie:
%{_prefix}/i686-pc-mingw32/bin/gcc %{_prefix}/i686-pc-mingw32/bin/g++ %{_prefix}/i686-pc-mingw32/bin/ld %{_prefix}/i686-pc-mingw32/bin/as %{_prefix}/i686-pc-mingw32/bin/strip etc.
Note that we don't support generating x86-64 binaries (or any other architecture) at the moment, but when we do those will have a different prefix.
Rationale This is the name which autoconf configure scripts expect when they are
invoked in cross-compiling mode. The /usr/i686-pc-mingw32/bin
directory is required by GCC, otherwise it invokes the wrong assembler and linker.
Naming of the root filesystem
The root filesystem contains Windows executables and DLLs and any other Windows-only files. It is necessary both because we need to store Windows libraries in order to link further libraries which depend on them, and also because MinGW requires a root filesystem location. The location (for i686 target) is provided by the macro:
%{_mingw_sysroot} %{_prefix}/i686-pc-mingw/sys-root
Rationale This is what the existing Fedora packages do, and very
similar to what Debian is doing (they use a different and inconsistent name, but
it is still a directory located directly under /usr), and is what MinGW expects.
Packaging DLLs
The Fedora MinGW SIG packages a range of common Linux libraries as Windows DLLs so that further libraries/programs can be compiled against them.
These libraries should be packaged in the directory:
%{_prefix}/i686-pc-mingw32/sys-root/mingw/lib
Rationale Specified by MinGW. Putting them in %{_libdir} doesn't sound like a good idea because they are useless to ordinary Fedora programs.
Packaging EXEs
Any Windows binaries should be packaged in the directory:
%{_prefix}/i686-pc-mingw32/sys-root/mingw/bin
Rationale Specified by MinGW. No use to anyone if they are in /usr/bin.
Packaging header files and other auxiliary files
Any auxiliary Windows files should be placed in the standard subdirectories of the root filesystem, for example:
%{_prefix}/i686-pc-mingw32/sys-root/mingw/include %{_prefix}/i686-pc-mingw32/sys-root/mingw/share etc.