# HG changeset patch
# User Markus Mützel <markus.muetzel@gmx.de>
# Date 1637243366 -3600
# Node ID 7c0066684448ea8d4f1cc9bc5d75785fca7664bc
# Parent  49b3f6c6d25525aa4e48f3845d61d86e01d28a90
Add support for building with UCRT on Windows.

* configure.ac: Add new configure switch "--with-windows-msvcrt". It can be set
to "msvcrt" (default) or "ucrt".
* Makefile.in: Make configure result of new switch available in makefile rules.
* src/mingw-w64.mk, src/build-gcc.mk: Select CRT when installing system headers
and when compiling system runtime.

See also: https://octave.discourse.group/t/1821

diff -r 49b3f6c6d255 -r 7c0066684448 Makefile.in
--- a/Makefile.in	Sun Nov 21 12:29:36 2021 +0100
+++ b/Makefile.in	Thu Nov 18 14:49:26 2021 +0100
@@ -80,6 +80,9 @@
 # Set to "yes" to use msys2
 USE_MSYS2 := @USE_MSYS2@
 
+# Set to "ucrt" or "msvcrt"
+HOST_MSVCRT := @HOST_MSVCRT@
+
 # Should match what config.guess prints for your system.
 # If cross compiling, you must set it manually (defaults are set by configure).
 ifeq ($(MXE_NATIVE_BUILD),yes)
diff -r 49b3f6c6d255 -r 7c0066684448 configure.ac
--- a/configure.ac	Sun Nov 21 12:29:36 2021 +0100
+++ b/configure.ac	Thu Nov 18 14:49:26 2021 +0100
@@ -99,6 +99,16 @@
    esac], [USE_MSYS2=yes])
 AC_SUBST(USE_MSYS2)
 
+# Use "msvcrt" or "ucrt" on Windows
+AC_ARG_WITH([windows-msvcrt],
+  [AS_HELP_STRING([--with-windows-msvcrt=msvcrt], [select C runtime for windows distribution (default: msvcrt)])],
+  [case $withval in
+     no) AC_MSG_ERROR([A runtime for Windows is required for --with-windows-msvcrt]) ;;
+     yes | "") HOST_MSVCRT=msvcrt ;;
+     *) HOST_MSVCRT="$withval" ;;
+   esac], [HOST_MSVCRT=msvcrt])
+AC_SUBST(HOST_MSVCRT)
+
 # try find pkg-config build paths
 BUILD_PKG_CONFIG_PATH=auto
 AC_ARG_WITH([build-pkg-config-path],
@@ -130,6 +140,10 @@
      *) AC_MSG_ERROR([bad value "$enableval" for --enable-windows-64]) ;;
    esac], [ENABLE_WINDOWS_64=yes])
 
+if test "$ENABLE_WINDOWS_64" = "no" && test "$HOST_MSVCRT" = "ucrt"; then
+  AC_MSG_NOTICE([UCRT is only supported with --enable-windows-64])
+fi
+
 AC_ARG_ENABLE([64],
   [AS_HELP_STRING([--enable-64],
     [use 64-bit integers for array dimensions and indexing])],
diff -r 49b3f6c6d255 -r 7c0066684448 src/build-gcc.mk
--- a/src/build-gcc.mk	Sun Nov 21 12:29:36 2021 +0100
+++ b/src/build-gcc.mk	Thu Nov 18 14:49:26 2021 +0100
@@ -54,6 +54,12 @@
     $(PKG)_WINAPI_VERSION_FLAGS := --with-default-win32-winnt=0x0601
   endif
 
+  ifneq ($(HOST_MSVCRT),ucrt)
+    $(PKG)_DEFAULT_MSVCRT := --with-default-msvcrt=msvcrt
+  else
+    $(PKG)_DEFAULT_MSVCRT := --with-default-msvcrt=ucrt
+  endif
+
   define $(PKG)_INSTALL_SYSTEM_HEADERS
     $($(PKG)_PRE_BUILD)
     # install mingw-w64 headers
@@ -66,6 +72,7 @@
       --enable-idl \
       --enable-secure-api \
       $($(PKG)_WINAPI_VERSION_FLAGS) \
+      $($(PKG)_DEFAULT_MSVCRT) \
       $(mingw-w64-headers_CONFIGURE_OPTS)
     $(MAKE) -C '$(1).headers' install
   endef
@@ -80,7 +87,8 @@
       --host='$(TARGET)' \
       --prefix='$(HOST_PREFIX)' \
       $(if $(filter $(TARGET), x86_64-w64-mingw32),--disable-lib32) \
-      --with-sysroot='$(HOST_PREFIX)'
+      --with-sysroot='$(HOST_PREFIX)' \
+      $($(PKG)_DEFAULT_MSVCRT)
     $(MAKE) -C '$(1).crt-build' -j '$(JOBS)' || $(MAKE) -C '$(1).crt-build' -j '$(JOBS)'
     $(MAKE) -C '$(1).crt-build' -j 1 install
 
diff -r 49b3f6c6d255 -r 7c0066684448 src/mingw-w64.mk
--- a/src/mingw-w64.mk	Sun Nov 21 12:29:36 2021 +0100
+++ b/src/mingw-w64.mk	Thu Nov 18 14:49:26 2021 +0100
@@ -22,6 +22,12 @@
   $(PKG)_WINAPI_VERSION_FLAGS := --with-default-win32-winnt=0x0601
 endif
 
+ifneq ($(HOST_MSVCRT),ucrt)
+  $(PKG)_DEFAULT_MSVCRT := --with-default-msvcrt=msvcrt
+else
+  $(PKG)_DEFAULT_MSVCRT := --with-default-msvcrt=ucrt
+endif
+
 define $(PKG)_BUILD
   mkdir '$(1).headers-build'
   cd '$(1).headers-build' && '$(1)/mingw-w64-headers/configure' \
@@ -30,7 +36,8 @@
     --enable-sdk=all \
     --enable-idl \
     --enable-secure-api \
-    $($(PKG)_WINAPI_VERSION_FLAGS)
+    $($(PKG)_WINAPI_VERSION_FLAGS) \
+    $($(PKG)_DEFAULT_MSVCRT)
 
   $(MAKE) -C '$(1).headers-build' install
 endef