scons: Support MinGW32 cross compiler.

To build an alternative opengl32.dll with Gallium's software-rasterizer from a
debian-based distribution run:

  sudo apt-get install mingw32
  scons platform=windows toolchain=crossmingw machine=x86 winsys=gdi dri=no

4 files changed, 202 insertions, 10 deletions

diff --git a/common.py b/common.py
index cc2582f1a4..d9e919ef76 100644
--- a/common.py
+++ b/common.py
@@ -60,6 +60,8 @@ def AddOptions(opts):
 											 allowed_values=('generic', 'ppc', 'x86', 'x86_64')))
 	opts.Add(EnumOption('platform', 'target platform', default_platform,
 											 allowed_values=('linux', 'cell', 'windows', 'winddk', 'wince')))
+	opts.Add(EnumOption('toolchain', 'compiler toolchain', 'default',
+											 allowed_values=('default', 'crossmingw')))
 	opts.Add(BoolOption('llvm', 'use LLVM', 'no'))
 	opts.Add(BoolOption('dri', 'build DRI drivers', default_dri))
 
diff --git a/scons/crossmingw.py b/scons/crossmingw.py
new file mode 100644
index 0000000000..cf4887ba46
--- /dev/null
+++ b/scons/crossmingw.py
@@ -0,0 +1,182 @@
+"""SCons.Tool.gcc
+
+Tool-specific initialization for MinGW (http://www.mingw.org/)
+
+There normally shouldn't be any need to import this module directly.
+It will usually be imported through the generic SCons.Tool.Tool()
+selection method.
+
+See also http://www.scons.org/wiki/CrossCompilingMingw
+"""
+
+#
+# Copyright (c) 2001, 2002, 2003, 2004 The SCons Foundation
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+import os
+import os.path
+import string
+
+import SCons.Action
+import SCons.Builder
+import SCons.Tool
+import SCons.Util
+
+# This is what we search for to find mingw:
+prefixes = SCons.Util.Split("""
+    mingw32-
+    mingw32msvc-
+    i386-mingw32-
+    i486-mingw32-
+    i586-mingw32-
+    i686-mingw32-
+    i386-mingw32msvc-
+    i486-mingw32msvc-
+    i586-mingw32msvc-
+    i686-mingw32msvc-
+""")
+
+def find(env):
+    for prefix in prefixes:
+        # First search in the SCons path and then the OS path:
+        if env.WhereIs(prefix + 'gcc') or SCons.Util.WhereIs(prefix + 'gcc'):
+            return prefix
+
+    return ''
+
+def shlib_generator(target, source, env, for_signature):
+    cmd = SCons.Util.CLVar(['$SHLINK', '$SHLINKFLAGS']) 
+
+    dll = env.FindIxes(target, 'SHLIBPREFIX', 'SHLIBSUFFIX')
+    if dll: cmd.extend(['-o', dll])
+
+    cmd.extend(['$SOURCES', '$_LIBDIRFLAGS', '$_LIBFLAGS'])
+
+    implib = env.FindIxes(target, 'LIBPREFIX', 'LIBSUFFIX')
+    if implib: cmd.append('-Wl,--out-implib,'+implib.get_string(for_signature))
+
+    def_target = env.FindIxes(target, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')
+    if def_target: cmd.append('-Wl,--output-def,'+def_target.get_string(for_signature))
+
+    return [cmd]
+
+def shlib_emitter(target, source, env):
+    dll = env.FindIxes(target, 'SHLIBPREFIX', 'SHLIBSUFFIX')
+    no_import_lib = env.get('no_import_lib', 0)
+
+    if not dll:
+        raise SCons.Errors.UserError, "A shared library should have exactly one target with the suffix: %s" % env.subst("$SHLIBSUFFIX")
+    
+    if not no_import_lib and \
+       not env.FindIxes(target, 'LIBPREFIX', 'LIBSUFFIX'):
+
+        # Append an import library to the list of targets.
+        target.append(env.ReplaceIxes(dll,  
+                                      'SHLIBPREFIX', 'SHLIBSUFFIX',
+                                      'LIBPREFIX', 'LIBSUFFIX'))
+
+    # Append a def file target if there isn't already a def file target
+    # or a def file source. There is no option to disable def file
+    # target emitting, because I can't figure out why someone would ever
+    # want to turn it off.
+    def_source = env.FindIxes(source, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')
+    def_target = env.FindIxes(target, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')
+    if not def_source and not def_target:
+        target.append(env.ReplaceIxes(dll,  
+                                      'SHLIBPREFIX', 'SHLIBSUFFIX',
+                                      'WIN32DEFPREFIX', 'WIN32DEFSUFFIX'))
+    
+    return (target, source)
+                         
+
+shlib_action = SCons.Action.Action(shlib_generator, generator=1)
+
+res_action = SCons.Action.Action('$RCCOM', '$RCCOMSTR')
+
+res_builder = SCons.Builder.Builder(action=res_action, suffix='.o',
+                                    source_scanner=SCons.Tool.SourceFileScanner)
+SCons.Tool.SourceFileScanner.add_scanner('.rc', SCons.Defaults.CScan)
+
+def generate(env):
+    mingw_prefix = find(env)
+
+    if mingw_prefix:
+        dir = os.path.dirname(env.WhereIs(mingw_prefix + 'gcc') or SCons.Util.WhereIs(mingw_prefix + 'gcc'))
+
+        # The mingw bin directory must be added to the path:
+        path = env['ENV'].get('PATH', [])
+        if not path: 
+            path = []
+        if SCons.Util.is_String(path):
+            path = string.split(path, os.pathsep)
+
+        env['ENV']['PATH'] = string.join([dir] + path, os.pathsep)
+
+    # Most of mingw is the same as gcc and friends...
+    gnu_tools = ['gcc', 'g++', 'gnulink', 'ar', 'gas']
+    for tool in gnu_tools:
+        SCons.Tool.Tool(tool)(env)
+
+    #... but a few things differ:
+    env['CC'] = mingw_prefix + 'gcc'
+    env['SHCCFLAGS'] = SCons.Util.CLVar('$CCFLAGS')
+    env['CXX'] = mingw_prefix + 'g++'
+    env['SHCXXFLAGS'] = SCons.Util.CLVar('$CXXFLAGS')
+    env['SHLINKFLAGS'] = SCons.Util.CLVar('$LINKFLAGS -shared')
+    env['SHLINKCOM']   = shlib_action
+    env.Append(SHLIBEMITTER = [shlib_emitter])
+    env['LINK'] = mingw_prefix + 'g++'
+    env['AR'] = mingw_prefix + 'ar'
+    env['RANLIB'] = mingw_prefix + 'ranlib'
+    env['LINK'] = mingw_prefix + 'g++'
+    env['AS'] = mingw_prefix + 'as'
+    env['WIN32DEFPREFIX']        = ''
+    env['WIN32DEFSUFFIX']        = '.def'
+    env['SHOBJSUFFIX'] = '.o'
+    env['STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME'] = 1
+
+    env['RC'] = mingw_prefix + 'windres'
+    env['RCFLAGS'] = SCons.Util.CLVar('')
+    env['RCCOM'] = '$RC $_CPPDEFFLAGS $_CPPINCFLAGS ${INCPREFIX}${SOURCE.dir} $RCFLAGS -i $SOURCE -o $TARGET'
+    env['BUILDERS']['RES'] = res_builder
+    
+    # Some setting from the platform also have to be overridden:
+    env['OBJPREFIX']      = ''
+    env['OBJSUFFIX']      = '.o'
+    env['LIBPREFIX']      = 'lib'
+    env['LIBSUFFIX']      = '.a'
+    env['SHOBJPREFIX']    = '$OBJPREFIX'
+    env['SHOBJSUFFIX']    = '$OBJSUFFIX'
+    env['PROGPREFIX']     = ''
+    env['PROGSUFFIX']     = '.exe'
+    env['LIBPREFIX']      = ''
+    env['LIBSUFFIX']      = '.lib'
+    env['SHLIBPREFIX']    = ''
+    env['SHLIBSUFFIX']    = '.dll'
+    env['LIBPREFIXES']    = [ '$LIBPREFIX' ]
+    env['LIBSUFFIXES']    = [ '$LIBSUFFIX' ]
+
+    env.AppendUnique(LIBS = ['iberty'])
+    env.AppendUnique(LINKFLAGS = ['-Wl,--enable-stdcall-fixup'])
+
+def exists(env):
+    return find(env)
diff --git a/scons/gallium.py b/scons/gallium.py
index c9d5368989..f7ac5e543e 100644
--- a/scons/gallium.py
+++ b/scons/gallium.py
@@ -170,22 +170,24 @@ def generate(env):
     #if env.get('quiet', False):
     #    quietCommandLines(env)
 
+    # Toolchain
+    platform = env['platform']
+    if env['toolchain'] == 'default':
+        if platform == 'winddk':
+            env['toolchain'] == 'winddk'
+        elif platform == 'wince':
+            env.Tool('wcesdk')
+            env['toolchain'] == 'wcesdk'
+    env.Tool(env['toolchain'])
+
     # shortcuts
     debug = env['debug']
     machine = env['machine']
     platform = env['platform']
     x86 = env['machine'] == 'x86'
     ppc = env['machine'] == 'ppc'
-    gcc = env['platform'] in ('linux', 'freebsd', 'darwin')
-    msvc = env['platform'] in ('windows', 'winddk', 'wince')
-
-    # Tool
-    if platform == 'winddk':
-        env.Tool('winddk')
-    elif platform == 'wince':
-        env.Tool('wcesdk')
-    else:
-        env.Tool('default')
+    gcc = env['platform'] in ('linux', 'freebsd', 'darwin') or env['toolchain'] == 'crossmingw'
+    msvc = env['platform'] in ('windows', 'winddk', 'wince') and env['toolchain'] != 'crossmingw'
 
     # Put build output in a separate dir, which depends on the current
     # configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
diff --git a/src/gallium/winsys/gdi/SConscript b/src/gallium/winsys/gdi/SConscript
index 170fdf5127..dce81ec1ca 100644
--- a/src/gallium/winsys/gdi/SConscript
+++ b/src/gallium/winsys/gdi/SConscript
@@ -13,6 +13,12 @@ if env['platform'] == 'windows':
 		'#src/mesa/main',
 	])
 
+	env.Append(CPPDEFINES = [
+		'__GL_EXPORTS',
+		'BUILD_GL32',
+		'_GNU_H_WINDOWS32_DEFINES',
+	])
+
 	sources = [
 		'opengl32.def',
 		'wgl.c',