depends: allow building packages with CMake

Allows upgrading libzip. Adding CMake as a dependency is inevitable as
both upstream and Qt6 uses CMake as their build system.

depends/funcs.mk

@@ -155,6 +155,33 @@ endif
 ifneq ($($(1)_ldflags),)
 $(1)_autoconf += LDFLAGS="$$($(1)_ldflags)"
 endif
+
+# We hardcode the library install path to "lib" to match the PKG_CONFIG_PATH
+# setting in depends/toolchain.cmake.in, which also hardcodes "lib".
+# Without this setting, CMake by default would use the OS library
+# directory, which might be "lib64" or something else, not "lib", on multiarch systems.
+$(1)_cmake=env CC="$$($(1)_cc)" \
+               CFLAGS="$$($(1)_cppflags) $$($(1)_cflags)" \
+               CXX="$$($(1)_cxx)" \
+               CXXFLAGS="$$($(1)_cppflags) $$($(1)_cxxflags)" \
+               LDFLAGS="$$($(1)_ldflags)" \
+               cmake -DCMAKE_INSTALL_PREFIX:PATH="$$($($(1)_type)_prefix)" \
+               -DCMAKE_AR=`which $$($(1)_ar)` \
+               -DCMAKE_NM=`which $$($(1)_nm)` \
+               -DCMAKE_RANLIB=`which $$($(1)_ranlib)` \
+               -DCMAKE_INSTALL_LIBDIR=lib/ \
+               -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
+               -DCMAKE_VERBOSE_MAKEFILE:BOOL=$(V) \
+               $$($(1)_config_opts)
+ifeq ($($(1)_type),build)
+$(1)_cmake += -DCMAKE_INSTALL_RPATH:PATH="$$($($(1)_type)_prefix)/lib"
+else
+ifneq ($(host),$(build))
+$(1)_cmake += -DCMAKE_SYSTEM_NAME=$($(host_os)_cmake_system_name)
+$(1)_cmake += -DCMAKE_C_COMPILER_TARGET=$(host)
+$(1)_cmake += -DCMAKE_CXX_COMPILER_TARGET=$(host)
+endif
+endif
 endef
 
 define int_add_cmds

depends/hosts/darwin.mk

@@ -77,3 +77,4 @@ darwin_debug_CFLAGS=-O1
 darwin_debug_CXXFLAGS=$(darwin_debug_CFLAGS)
 
 darwin_cmake_system=Darwin
+darwin_cmake_system_name=Darwin

depends/hosts/linux.mk

@@ -29,3 +29,7 @@ i686_linux_CXX=$(default_host_CXX) -m32
 x86_64_linux_CC=$(default_host_CC) -m64
 x86_64_linux_CXX=$(default_host_CXX) -m64
 endif
+
+
+linux_cmake_system_name=Linux
+linux_cmake_system_version=3.17.0

depends/hosts/mingw32.mk

@@ -12,3 +12,7 @@ mingw32_debug_CFLAGS=-O1
 mingw32_debug_CXXFLAGS=$(mingw32_debug_CFLAGS)
 
 mingw32_debug_CPPFLAGS=-D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC
+
+mingw32_cmake_system_name=Windows
+# Windows 7 (NT 6.1).
+mingw32_cmake_system_version=6.1