[glibmm] NMake MAkefiles: Add USE_MESON_LIBS

[Chun-wei Fan <fanchunwei src gnome org>]

commit 913d5ff0b0c531540bdc966848c844b25ed65210
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Thu Dec 26 18:18:04 2019 +0800

    NMake MAkefiles: Add USE_MESON_LIBS
    
    This allows one to use C++ dependencies built using Meson in an easier
    way, as applicable.

 MSVC_NMake/config-msvc.mak |  7 ++++++-
 MSVC_NMake/info-msvc.mak   | 11 +++++++----
 README.win32               |  4 +++-
 3 files changed, 16 insertions(+), 6 deletions(-)
---
diff --git a/MSVC_NMake/config-msvc.mak b/MSVC_NMake/config-msvc.mak
index 035e263c..d7e02305 100644
--- a/MSVC_NMake/config-msvc.mak
+++ b/MSVC_NMake/config-msvc.mak
@@ -42,9 +42,14 @@ GIOMM_EX_CFLAGS = $(GIOMM_BASE_CFLAGS) $(GLIBMM_EXTRA_INCLUDES)
 #          giomm-vc$(VSVER)0-$(GLIBMM_MAJOR_VERSION)_$(GLIBMM_MINOR_VERSION).dll or
 #          giomm-vc$(VSVER)0-d-$(GLIBMM_MAJOR_VERSION)_$(GLIBMM_MINOR_VERSION).dll at least
 
+!ifdef USE_MESON_LIBS
+LIBSIGC_LIBNAME = sigc++-$(LIBSIGC_MAJOR_VERSION).$(LIBSIGC_MINOR_VERSION)
+LIBSIGC_DLL = $(LIBSIGC_LIBNAME)-0.dll
+!else
 LIBSIGC_LIBNAME = sigc-vc$(VSVER)0$(DEBUG_SUFFIX)-$(LIBSIGC_MAJOR_VERSION)_$(LIBSIGC_MINOR_VERSION)
-
 LIBSIGC_DLL = $(LIBSIGC_LIBNAME).dll
+!endif
+
 LIBSIGC_LIB = $(LIBSIGC_LIBNAME).lib
 
 GLIBMM_LIBNAME = glibmm-vc$(VSVER)0$(DEBUG_SUFFIX)-$(GLIBMM_MAJOR_VERSION)_$(GLIBMM_MINOR_VERSION)
diff --git a/MSVC_NMake/info-msvc.mak b/MSVC_NMake/info-msvc.mak
index d25f962e..152c0cce 100644
--- a/MSVC_NMake/info-msvc.mak
+++ b/MSVC_NMake/info-msvc.mak
@@ -9,10 +9,10 @@ all-build-info:
 
 help:
        @echo.
-       @echo ============================
-       @echo Building cairomm Using NMake
-       @echo ============================
-       @echo nmake /f Makefile.vc CFG=[release^|debug] ^<PREFIX=PATH^> <option1=xxx option2=xxx>
+       @echo ===========================
+       @echo Building glibmm Using NMake
+       @echo ===========================
+       @echo nmake /f Makefile.vc CFG=[release^|debug] ^<PREFIX=PATH^> ^<option1=xxx option2=xxx^>
        @echo.
        @echo Where:
        @echo ------
@@ -30,6 +30,9 @@ help:
        @echo GLIB_COMPILE_SCHEMAS: Location of the glib-compile-schemas tool,
        @echo if it cannot be found in $(PREFIX)\bin.  This tool is needed for the
        @echo giomm settings example program.
+       @echo.
+       @echo USE_MESON_LIBS: Use DLLs and LIBs of C++ dependencies that are built with Meson,
+       @echo as applicable.
        @echo ======
        @echo A 'clean' target is supported to remove all generated files, intermediate
        @echo object files and binaries for the specified configuration.
diff --git a/README.win32 b/README.win32
index 468bbbd3..a186c4b5 100644
--- a/README.win32
+++ b/README.win32
@@ -53,7 +53,9 @@ giomm DLLs, along with their example programs.  If a prefix other than
 $(srcroot)\..\vs15\$(Platform) is desired, pass in PREFIX=$(your_prefix)
 in the NMake command line.  In order to build the giomm settings example
 program, the glib-compile-schemas needs to reside in $(PREFIX)\bin, or
-it must be specified via passing in GLIB_COMPILE_SCHEMAS.
+it must be specified via passing in GLIB_COMPILE_SCHEMAS.  If using C++
+dependencies that are built with Meson, specify USE_MESON_LIBS=1 in your
+NMake command line.
 
 A 'tests' target will build the test programs for glibmm and giomm, an
 'install' target is provided to copy the built DLLs and LIBs, along with