build: Add NMake makefiles for Visual Studio builds

This adds a set of NMake Makefiles that can be used to build pkg-config on
Windows using Visual Studio.  Note that, since the Visual Studio builds of
GLib does not use pkg-config, this NMake Makefile set does not support the
build of the bundled GLib sources, instead, having GLib built beforehand
is required.

Makefile.am

@@ -47,6 +47,8 @@ dist_doc_DATA = pkg-config-guide.html
 dist_man_MANS = pkg-config.1
 EXTRA_DIST =	\
 	README.win32		\
+	detectenv-msvc.mak	\
+	Makefile.vc		\
 	config.h.win32
 
 # gcov test coverage

Makefile.vc

@@ -0,0 +1,96 @@
+# Note: This does assume an existing GLib installation!
+# Visual Studio builds of GLib does not need an existing pkg-config
+# installation, so build GLib first before using this.
+
+# Change these if necessary.  If building from GLib's included
+# Visual Studio projects, this should be able to locate the GLib build
+# out-of-the-box if they were not moved.  GLib's headers will be found
+# in $(GLIB_PREFIX)\include\glib-2.0 and $(GLIB_PREFIX)\lib\glib-2.0\include
+# and its import library will be found in $(GLIB_PREFIX)\lib.
+
+GLIB_PREFIX = ..\vs$(VSVER)\$(PLAT)
+
+# The items below this line should not be changed, unless one is maintaining
+# the NMake Makefiles.
+
+!include detectenv-msvc.mak
+
+!if "$(VALID_CFGSET)" == "TRUE"
+CFLAGS = $(CFLAGS_ADD) /W3 /Zi /FImsvc_recommended_pragmas.h /I.		\
+	/I$(GLIB_PREFIX)\include\glib-2.0					\
+	/I$(GLIB_PREFIX)\lib\glib-2.0\include
+
+# PKG_CONFIG_SYSTEM_INCLUDE_PATH and PKG_CONFIG_SYSTEM_LIBRARY_PATH only
+# work for GCC builds for now, so just set this to nothing for now
+
+pkg_config_CFLAGS =	\
+	$(CFLAGS)				\
+	/DHAVE_CONFIG_H				\
+	/DPKG_CONFIG_SYSTEM_INCLUDE_PATH="\"\""	\
+	/DPKG_CONFIG_SYSTEM_LIBRARY_PATH="\"\""
+
+LDFLAGS_BASE = $(LDFLAGS_ARCH) /libpath:$(GLIB_PREFIX)\lib /DEBUG
+NULL=
+
+!if "$(CFG)" == "debug"
+LDFLAGS = $(LDFLAGS_BASE)
+!else
+LDFLAGS = $(LDFLAGS_BASE) /opt:ref /LTCG
+!endif
+
+!include Makefile.sources
+
+# Convert the source (*.c) listing to object (.obj) listing in
+# another NMake Makefile module, include it, and clean it up.
+
+!if [echo pkg_config_OBJS = \> objs.mak]
+!endif
+
+!if [for %c in ($(pkg_config_SOURCES)) do @if "%~xc" == ".c" echo. ^$(CFG)\^$(PLAT)\pkg-config\%~nc.obj \>> objs.mak]
+!endif
+
+!if [echo. ^$(NULL)>> objs.mak]
+!endif
+
+!include objs.mak
+
+!if [del /f /q objs.mak]
+!endif
+
+pkg_config_LIBS = glib-2.0.lib
+
+{}.c{$(CFG)\$(PLAT)\pkg-config\}.obj::
+	$(CC) $(pkg_config_CFLAGS) /Fo$(CFG)\$(PLAT)\pkg-config\ /c @<<
+$<
+<<
+
+all: $(CFG)\$(PLAT)\pkg-config.exe
+
+$(CFG)\$(PLAT)\pkg-config.exe: $(CFG)\$(PLAT)\pkg-config config.h $(pkg_config_OBJS)
+	link $(LDFLAGS) $(pkg_config_LIBS) -out:$@ @<<
+$(pkg_config_OBJS)
+<<
+	@-if exist $@.manifest mt /manifest $@.manifest /outputresource:$@;1
+
+$(CFG)\$(PLAT)\pkg-config:
+	@-mkdir $@
+
+config.h: config.h.win32
+	@-copy $@.win32 $@
+
+clean:
+	@-del /f /q $(CFG)\$(PLAT)\*.pdb
+	@-del /f /q $(CFG)\$(PLAT)\*.exe.manifest
+	@-del /f /q $(CFG)\$(PLAT)\*.exe
+	@-del /f /q $(CFG)\$(PLAT)\*.ilk
+	@-del /f /q $(CFG)\$(PLAT)\pkg-config\*.obj
+	@-rmdir /s /q $(CFG)\$(PLAT)
+	@-del vc$(VSVER)0.pdb
+	@-del config.h
+
+!else
+all:
+	@echo You need to specify a valid configuration, via
+	@echo CFG=release or CFG=debug
+!endif
+

detectenv-msvc.mak

@@ -0,0 +1,67 @@
+# Check to see we are configured to build with MSVC (MSDEVDIR, MSVCDIR or
+# VCINSTALLDIR) or with the MS Platform SDK (MSSDK or WindowsSDKDir)
+!if !defined(VCINSTALLDIR) && !defined(WINDOWSSDKDIR)
+MSG = ^
+This Makefile is only for Visual Studio 2008 and later.^
+You need to ensure that the Visual Studio Environment is properly set up^
+before running this Makefile.
+!error $(MSG)
+!endif
+
+ERRNUL  = 2>NUL
+_HASH=^#
+
+!if ![echo VCVERSION=_MSC_VER > vercl.x] \
+    && ![echo $(_HASH)if defined(_M_IX86) >> vercl.x] \
+    && ![echo PLAT=Win32 >> vercl.x] \
+    && ![echo $(_HASH)elif defined(_M_AMD64) >> vercl.x] \
+    && ![echo PLAT=x64 >> vercl.x] \
+    && ![echo $(_HASH)endif >> vercl.x] \
+    && ![cl -nologo -TC -P vercl.x $(ERRNUL)]
+!include vercl.i
+!if ![echo VCVER= ^\> vercl.vc] \
+    && ![set /a $(VCVERSION) / 100 - 6 >> vercl.vc]
+!include vercl.vc
+!endif
+!endif
+!if ![del $(ERRNUL) /q/f vercl.x vercl.i vercl.vc]
+!endif
+
+!if $(VCVERSION) > 1499 && $(VCVERSION) < 1600
+VSVER = 9
+!elseif $(VCVERSION) > 1599 && $(VCVERSION) < 1700
+VSVER = 10
+!elseif $(VCVERSION) > 1699 && $(VCVERSION) < 1800
+VSVER = 11
+!elseif $(VCVERSION) > 1799 && $(VCVERSION) < 1900
+VSVER = 12
+!elseif $(VCVERSION) > 1899 && $(VCVERSION) < 2000
+VSVER = 14
+!else
+VSVER = 0
+!endif
+
+!if "$(VSVER)" == "0"
+MSG = ^
+This NMake Makefile set supports Visual Studio^
+9 (2008) through 14 (2015).  Your Visual Studio^
+version is not supported.
+!error $(MSG)
+!endif
+
+VALID_CFGSET = FALSE
+!if "$(CFG)" == "release" || "$(CFG)" == "debug"
+VALID_CFGSET = TRUE
+!endif
+
+!if "$(CFG)" == "release"
+CFLAGS_ADD = /MD /O2 /GL
+!else
+CFLAGS_ADD = /MDd /Od
+!endif
+
+!if "$(PLAT)" == "x64"
+LDFLAGS_ARCH = /machine:x64
+!else
+LDFLAGS_ARCH = /machine:x86
+!endif