support building on Windows using MinGW

Here is a patch for getting Avian to build in Windows. I used MinGW
and MSYS for the build environment. The patch has the following
changes:

1. java-nio.cpp: Had to add an include and remove a function
declaration that was reported as duplicate.
2. readme.txt: Updated the instructions to include notes about
building on Windows.
3. makefile: Added a conditional for MinGW. I left the existing "ifeq
($(platform),windows)" conditional alone so as to not break
cross-compiled Windows builds. There are some similarities between the
two, so it might be possible to combine portions of them in an elegant
manner. Since I'm not sure how the cross-compiled builds have been
done, I didn't want to mess with that portion of the makefile.

classpath/java-nio.cpp

@@ -14,6 +14,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include "machine.h"
 #include "jni.h"
 #include "jni-util.h"
 
@@ -35,8 +36,6 @@
 typedef int socklen_t;
 #endif
 
-inline void* operator new(size_t, void* p) throw() { return p; }
-
 namespace {
 
 inline jbyteArray

makefile

@@ -77,6 +77,8 @@ pointer-size = 8
 
 so-prefix = lib
 so-suffix = .so
+exe-suffix = 
+
 
 shared = -shared
 
@@ -97,7 +99,11 @@ ifeq ($(platform),darwin)
 	shared = -dynamiclib
 endif
 
-ifeq ($(platform),windows)
+ifeq ($(platform),mingw32_nt-6.0)
+	# A native Windows build (i.e. not cross-compiled).
+	build-cflags = $(common-cflags) \
+		-I$(JAVA_HOME)/include/win32 -I$(src) -mthreads
+	lflags = $(common-lflags) -lmthreads -ldl		
 	inc = $(root)/win32/include
 	lib = $(root)/win32/lib
 
@@ -106,6 +112,31 @@ ifeq ($(platform),windows)
 
 	so-prefix =
 	so-suffix = .dll
+	exe-suffix = .exe
+
+	cxx = g++
+	cc = gcc
+	dlltool = dlltool
+	ar = ar
+	ranlib = ranlib
+	objcopy = objcopy
+
+	rdynamic = -Wl,--export-dynamic
+	lflags = -L$(lib) $(common-lflags) -lws2_32 -mwindows -mconsole
+	cflags = $(common-cflags) -I$(inc)
+endif
+
+ifeq ($(platform),windows)
+	# A Windows cross-compiled build
+	inc = $(root)/win32/include
+	lib = $(root)/win32/lib
+
+	system = windows
+	object-format = pe-i386
+
+	so-prefix =
+	so-suffix = .dll
+	exe-suffix = .exe
 
 	cxx = i586-mingw32msvc-g++
 	cc = i586-mingw32msvc-gcc
@@ -214,9 +245,9 @@ generator-objects = \
 generator = $(native-build)/generator
 
 static-library = $(native-build)/lib$(name).a
-executable = $(native-build)/$(name)
+executable = $(native-build)/$(name)${exe-suffix}
 dynamic-library = $(native-build)/$(so-prefix)$(name)$(so-suffix)
-executable-dynamic = $(native-build)/$(name)-dynamic
+executable-dynamic = $(native-build)/$(name)-dynamic${exe-suffix}
 
 classpath-sources = $(shell find $(classpath) -name '*.java')
 classpath-classes = \
@@ -369,7 +400,9 @@ $(executable): \
 		$(vm-objects) $(classpath-object) $(jni-objects) $(driver-object) \
 		$(boot-object)
 	@echo "linking $(@)"
-ifeq ($(platform),windows)
+
+ifneq (,$(filter $(platform),windows mingw32_nt-6.0))
+	# This is either cross-compiled or native Windows build
 	$(dlltool) -z $(@).def $(^)
 	$(dlltool) -k -d $(@).def -e $(@).exp
 	$(cc) $(@).exp $(^) $(lflags) -o $(@)

readme.txt

@@ -10,7 +10,17 @@ on Mac OS X:
  $ export JAVA_HOME=/Library/Java/Home
  $ make
  $ build/darwin-i386-compile-fast/avian -cp build/test Hello
-
+ 
+on Windows:
+Install the current MSYS from the MinGW page (selecting the C and C++
+compilers). Follow the post-install options to create the file system
+link to the compiler. Upgrade to GNU make 3.81 by downloading the
+current release of GNU make from the same download page as the MSYS
+download page. Extract the tarball into your MSYS installation
+directory. Open the MSYS shell and:
+ $ export JAVA_HOME=C:/my/java/install # be sure to use forward slashes
+ $ make
+ $ build/mingw32_nt-6.0-i386-compile-fast/avian -cp build/test Hello
 
 Introduction
 ------------
@@ -237,3 +247,9 @@ on Mac OS X:
  $ g++ -rdynamic *.o -ldl -lpthread -lz -o hello -framework CoreFoundation
  $ strip -S -x hello
 
+on Windows:
+ $ g++ -I$JAVA_HOME/include -I../../win32/include -D_JNI_IMPLEMENTATION_ -c main.cpp -o main.o
+ $ dlltool -z hello.def *.o
+ $ dlltool -k -d hello.def -e hello.exp
+ $ g++ hello.exp *.o -L../../win32/lib -lmingwthrd -lm -lz -lws2_32 -mwindows -mconsole -o hello 
+ $ strip --strip-all hello.exe