host-toolchain plugin: add pkgconf/pkg-config

plugins/examples/host-toolchain/README.md

@@ -48,6 +48,17 @@ terminal emulators:
 Make is difficult to cross-compile so it is downloaded from the [source
 recommended by the GNU Make team](http://git.savannah.gnu.org/cgit/make.git/tree/README.W32.template).
 
+#### pkgconf/pkg-config
+
+```
+make pkgconf-host MXE_PLUGIN_DIRS=plugins/examples/host-toolchain/
+```
+
+This will cross-compile `pkgconf` and create the `pkg-config` wrapper. The
+wrapper requires `/bin/sh` so one of the [MSYS2][msys2] options should be used.
+Run the `usr/{target}/bin/test-pkgconf-host` script to build `libffi` test
+with non-standard include paths.
+
 #### Qt5 tools (`qmake.exe`, `rcc.exe`, etc.)
 
 ```

plugins/examples/host-toolchain/pkgconf-host.mk

@@ -0,0 +1,47 @@
+# This file is part of MXE.
+# See index.html for further information.
+
+PKG             := pkgconf-host
+$(PKG)_IGNORE    = $(pkgconf_IGNORE)
+$(PKG)_VERSION   = $(pkgconf_VERSION)
+$(PKG)_CHECKSUM  = $(pkgconf_CHECKSUM)
+$(PKG)_SUBDIR    = $(pkgconf_SUBDIR)
+$(PKG)_FILE      = $(pkgconf_FILE)
+$(PKG)_URL       = $(pkgconf_URL)
+$(PKG)_URL_2     = $(pkgconf_URL_2)
+$(PKG)_DEPS     := gcc libffi
+
+define $(PKG)_UPDATE
+    echo $(pkgconf_VERSION)
+endef
+
+define $(PKG)_BUILD
+    cd '$(1)' && ./autogen.sh
+    cd '$(1)' && ./configure \
+        $(MXE_CONFIGURE_OPTS)
+    $(MAKE) -C '$(1)' -j '$(JOBS)'
+    $(MAKE) -C '$(1)' -j 1 install
+
+    # create pkg-config script with relative paths
+    (echo '#!/bin/sh'; \
+     echo 'PKG_CONFIG_PATH="../qt5/lib/pkgconfig":"$$PKG_CONFIG_PATH_$(subst .,_,$(subst -,_,$(TARGET)))" \
+           PKG_CONFIG_LIBDIR='\''../lib/pkgconfig'\'' \
+           exec '../bin/pkgconf' \
+               $(if $(BUILD_STATIC),--static) \
+               --define-variable=prefix=.. \
+               "$$@"' \
+    )         > '$(PREFIX)/$(TARGET)/bin/pkg-config'
+    chmod 0755 '$(PREFIX)/$(TARGET)/bin/pkg-config'
+
+    # test compilation on host with libffi in non-std prefix
+    cp '$(PWD)/src/libffi-test.c' '$(PREFIX)/$(TARGET)/bin/test-$(PKG).c'
+    (echo '#!/bin/sh'; \
+     echo 'export PATH=../bin:$PATH'; \
+     echo 'gcc -v \
+               -W -Wall -Werror -ansi -pedantic \
+               test-$(PKG).c -o test-$(PKG).exe \
+               `pkg-config --cflags --libs libffi`'; \
+     echo 'test-$(PKG).exe'; \
+    )        > '$(PREFIX)/$(TARGET)/bin/test-$(PKG)'
+    chmod 0755 '$(PREFIX)/$(TARGET)/bin/test-$(PKG)'
+endef