Port leveldb to MinGW32

Several changes to make the native windows leveldb code compile
with mingw32 and run on 32-bit Windows:
* Remove -std=c++0x dependency (modified code to use NULL instead of
  nullptr)
* Link with -lshlwapi
* Only #define snprintf/etc if compiling with Visual Studio
* Do not link against DbgHelp.lib (wrote a CreateDir instead of using
  DbgHelp's MakeSureDirectoryPathExists
* Define WINVER=0x0500 so MinGW32 can use the 64-bit-filesystem Windows
  api calls
* Define __USE_MINGW_ANSI_STDIO=1 to use MinGW's printf (which supports
  %ll)

I also cleaned up makefile.mingw, assuming that dependencies would be in
the standard /usr/local/{include,lib} by default but allowing overriding
with make DEPSDIR=... etc

src/makefile.mingw

@@ -2,25 +2,41 @@
 # Distributed under the MIT/X11 software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-USE_UPNP:=0
+# Makefile for the MinGW g++ compiler/toolchain
+#
+# Assumes Berkeley DB, Boost, and OpenSSL have all been compiled and installed
+# into /usr/local (/usr/local/include, /usr/local/lib).
+#
+# If dependencies are somewhere else, run 'make DEPSDIR=/path/'
+#
+# Boost libraries are given wacky names that include the particular version of
+# boost you're using; set BOOST_SUFFIX appropriately.
+#
+# 'make clean' assumes it is running inside a MSYS shell, and uses 'rm'
+# to remove files.
+
+USE_UPNP:=-
 USE_IPV6:=1
 
+DEPSDIR?=/usr/local
+BOOST_SUFFIX?=-mgw46-mt-sd-1_52
+
 INCLUDEPATHS= \
- -I"C:\boost-1.50.0-mgw" \
- -I"C:\db-4.8.30.NC-mgw\build_unix" \
- -I"C:\openssl-1.0.1c-mgw\include"
+ -I"$(CURDIR)" \
+ -I"$(DEPSDIR)/include"
 
 LIBPATHS= \
- -L"C:\boost-1.50.0-mgw\stage\lib" \
- -L"C:\db-4.8.30.NC-mgw\build_unix" \
- -L"C:\openssl-1.0.1c-mgw"
+ -L"$(CURDIR)/leveldb" \
+ -L"$(DEPSDIR)/lib"
 
 LIBS= \
- -l boost_system-mgw45-mt-s-1_50 \
- -l boost_filesystem-mgw45-mt-s-1_50 \
- -l boost_program_options-mgw45-mt-s-1_50 \
- -l boost_thread-mgw45-mt-s-1_50 \
- -l boost_chrono-mgw45-mt-s-1_50 \
+ -l leveldb \
+ -l memenv \
+ -l boost_system$(BOOST_SUFFIX) \
+ -l boost_filesystem$(BOOST_SUFFIX) \
+ -l boost_program_options$(BOOST_SUFFIX) \
+ -l boost_thread$(BOOST_SUFFIX) \
+ -l boost_chrono$(BOOST_SUFFIX) \
  -l db_cxx \
  -l ssl \
  -l crypto
@@ -37,8 +53,6 @@ ifndef USE_UPNP
 	override USE_UPNP = -
 endif
 ifneq (${USE_UPNP}, -)
- INCLUDEPATHS += -I"C:\miniupnpc-1.6-mgw"
- LIBPATHS += -L"C:\miniupnpc-1.6-mgw"
  LIBS += -l miniupnpc -l iphlpapi
  DEFS += -DSTATICLIB -DUSE_UPNP=$(USE_UPNP)
 endif
@@ -94,12 +108,12 @@ test check: test_bitcoin.exe FORCE
 #
 # LevelDB support
 #
-LIBS += $(CURDIR)/leveldb/libleveldb.a $(CURDIR)/leveldb/libmemenv.a
 DEFS += $(addprefix -I,$(CURDIR)/leveldb/include)
 DEFS += $(addprefix -I,$(CURDIR)/leveldb/helpers)
-# TODO: If this fails, try adding a ranlib libleveldb.a && ranlib libmemenv.a
+
 leveldb/libleveldb.a:
-	cd leveldb && $(MAKE) libleveldb.a libmemenv.a && cd ..
+	cd leveldb && $(MAKE) OPT="$(DEBUGFLAGS)" TARGET_OS=NATIVE_WINDOWS libleveldb.a libmemenv.a && cd ..
+
 obj/leveldb.o: leveldb/libleveldb.a
 
 obj/%.o: %.cpp $(HEADERS)
@@ -114,11 +128,12 @@ obj-test/%.o: test/%.cpp $(HEADERS)
 	g++ -c $(TESTDEFS) $(CFLAGS) -o $@ $<
 
 test_bitcoin.exe: $(TESTOBJS) $(filter-out obj/init.o,$(OBJS:obj/%=obj/%))
-	g++ $(CFLAGS) $(LDFLAGS) -o $@ $(LIBPATHS) $^ -lboost_unit_test_framework $(LIBS)
+	g++ $(CFLAGS) $(LDFLAGS) -o $@ $(LIBPATHS) $^ -lboost_unit_test_framework$(BOOST_SUFFIX) $(LIBS)
 
 clean:
-	-del /Q bitcoind test_bitcoin
-	-del /Q obj\*
-	-del /Q obj-test\*
+	rm -f bitcoind.exe test_bitcoin.exe
+	rm -f obj/*
+	rm -f obj-test/*
+	cd leveldb && $(MAKE) TARGET_OS=NATIVE_WINDOWS clean && cd ..
 
 FORCE: