Add MSVC to Makefile

Enable MSVC builds with GNU Make by simply calling
    make MSVC=1
(Debug build possible by adding DEBUG=1 as well)

Two scripts, clink.pl and lib.pl, are used to convert certain GCC
specific command line options into something MSVC understands.
By building for MSVC with GNU Make, we can ensure that the MSVC
port always follows the latest code, and does not lag behind due
to unmaintained NMake Makefile or IDE projects.

Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -876,6 +876,58 @@ ifneq (,$(findstring CYGWIN,$(uname_S)))
 	COMPAT_OBJS += compat/cygwin.o
 	UNRELIABLE_FSTAT = UnfortunatelyYes
 endif
+ifdef MSVC
+	pathsep = ;
+	NO_PREAD = YesPlease
+	NO_OPENSSL = YesPlease
+	NO_LIBGEN_H = YesPlease
+	NO_SYMLINK_HEAD = YesPlease
+	NO_IPV6 = YesPlease
+	NO_SETENV = YesPlease
+	NO_UNSETENV = YesPlease
+	NO_STRCASESTR = YesPlease
+	NO_STRLCPY = YesPlease
+	NO_MEMMEM = YesPlease
+	# NEEDS_LIBICONV = YesPlease
+	NO_ICONV = YesPlease
+	NO_C99_FORMAT = YesPlease
+	NO_STRTOUMAX = YesPlease
+	NO_STRTOULL = YesPlease
+	NO_MKDTEMP = YesPlease
+	NO_MKSTEMPS = YesPlease
+	SNPRINTF_RETURNS_BOGUS = YesPlease
+	NO_SVN_TESTS = YesPlease
+	NO_PERL_MAKEMAKER = YesPlease
+	RUNTIME_PREFIX = YesPlease
+	NO_POSIX_ONLY_PROGRAMS = YesPlease
+	NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
+	NO_NSEC = YesPlease
+	USE_WIN32_MMAP = YesPlease
+	# USE_NED_ALLOCATOR = YesPlease
+	UNRELIABLE_FSTAT = UnfortunatelyYes
+	OBJECT_CREATION_USES_RENAMES = UnfortunatelyNeedsTo
+	NO_REGEX = YesPlease
+	NO_CURL = YesPlease
+	NO_PTHREADS = YesPlease
+
+	CC = compat/vcbuild/scripts/clink.pl
+	AR = compat/vcbuild/scripts/lib.pl
+	CFLAGS =
+	BASIC_CFLAGS = -nologo -I. -I../zlib -Icompat/vcbuild -Icompat/vcbuild/include -DWIN32-D_CONSOLE -DHAVE_STRING_H -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE
+	COMPAT_OBJS = compat/msvc.o compat/fnmatch/fnmatch.o compat/winansi.o
+	COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -DHAVE_ALLOCA_H -Icompat -Icompat/fnmatch -Icompat/regex -Icompat/fnmatch -DSTRIP_EXTENSION=\".exe\"
+	BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -SUBSYSTEM:CONSOLE -NODEFAULTLIB:MSVCRT.lib
+	EXTLIBS = advapi32.lib shell32.lib wininet.lib ws2_32.lib
+	lib =
+ifndef DEBUG
+	BASIC_CFLAGS += -GL -Os -MT
+	BASIC_LDFLAGS += -LTCG
+	AR += -LTCG
+else
+	BASIC_CFLAGS += -Zi -MTd
+endif
+	X = .exe
+else
 ifneq (,$(findstring MINGW,$(uname_S)))
 	pathsep = ;
 	NO_PREAD = YesPlease
@@ -924,6 +976,7 @@ else
 	NO_PTHREADS = YesPlease
 endif
 endif
+endif
 
 -include config.mak.autogen
 -include config.mak
@@ -1326,7 +1379,7 @@ strip: $(PROGRAMS) git$X
 git.o: git.c common-cmds.h GIT-CFLAGS
 	$(QUIET_CC)$(CC) -DGIT_VERSION='"$(GIT_VERSION)"' \
 		'-DGIT_HTML_PATH="$(htmldir_SQ)"' \
-		$(ALL_CFLAGS) -c $(filter %.c,$^)
+		$(ALL_CFLAGS) -o $@ -c $(filter %.c,$^)
 
 git$X: git.o $(BUILTIN_OBJS) $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ git.o \

compat/vcbuild/scripts/clink.pl

@@ -0,0 +1,48 @@
+#!/usr/bin/perl -w
+######################################################################
+# Compiles or links files
+#
+# This is a wrapper to facilitate the compilation of Git with MSVC
+# using GNU Make as the build system. So, instead of manipulating the
+# Makefile into something nasty, just to support non-space arguments
+# etc, we use this wrapper to fix the command line options
+#
+# Copyright (C) 2009 Marius Storm-Olsen <mstormo@gmail.com>
+######################################################################
+use strict;
+my @args = ();
+my @cflags = ();
+my $is_linking = 0;
+while (@ARGV) {
+	my $arg = shift @ARGV;
+	if ("$arg" =~ /^-[DIMGO]/) {
+		push(@cflags, $arg);
+	} elsif ("$arg" eq "-o") {
+		my $file_out = shift @ARGV;
+		if ("$file_out" =~ /exe$/) {
+			$is_linking = 1;
+			push(@args, "-OUT:$file_out");
+		} else {
+			push(@args, "-Fo$file_out");
+		}
+	} elsif ("$arg" eq "-lz") {
+		push(@args, "zlib.lib");
+	} elsif ("$arg" eq "-liconv") {
+		push(@args, "iconv.lib");
+	} elsif ("$arg" =~ /^-L/ && "$arg" ne "-LTCG") {
+		$arg =~ s/^-L/-LIBPATH:/;
+		push(@args, $arg);
+	} elsif ("$arg" =~ /^-R/) {
+		# eat
+	} else {
+		push(@args, $arg);
+	}
+}
+if ($is_linking) {
+	unshift(@args, "link.exe");
+} else {
+	unshift(@args, "cl.exe");
+	push(@args, @cflags);
+}
+#printf("**** @args\n");
+exit system(@args);

compat/vcbuild/scripts/lib.pl

@@ -0,0 +1,26 @@
+#!/usr/bin/perl -w
+######################################################################
+# Libifies files on Windows
+#
+# This is a wrapper to facilitate the compilation of Git with MSVC
+# using GNU Make as the build system. So, instead of manipulating the
+# Makefile into something nasty, just to support non-space arguments
+# etc, we use this wrapper to fix the command line options
+#
+# Copyright (C) 2009 Marius Storm-Olsen <mstormo@gmail.com>
+######################################################################
+use strict;
+my @args = ();
+while (@ARGV) {
+	my $arg = shift @ARGV;
+	if ("$arg" eq "rcs") {
+		# Consume the rcs option
+	} elsif ("$arg" =~ /\.a$/) {
+		push(@args, "-OUT:$arg");
+	} else {
+		push(@args, $arg);
+	}
+}
+unshift(@args, "lib.exe");
+# printf("**** @args\n");
+exit system(@args);