[OE-core][PATCH] classes/cmake: Fix host detection

["Joshua Watt" <JPEWhacker@gmail.com>]

Fixes the class to use HOST_OS and HOST_ARCH to set the cmake SYSTEM
variables. The HOST variables should be used instead of
TARGET_OS/TARGET_ARCH because we want to control how cmake compiles for
where the package is going to run (the host), not what it will be
generating output for (the target). The distinction is only really
relevant when building canadian cross recipes.

Also fix up the host OS detection to account for MinGW by setting
CMAKE_SYSTEM_NAME to "Windows". This eliminates the need for meta-mingw
to patch this in all the cmake recipes it builds.

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
---
 meta/classes/cmake.bbclass | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/meta/classes/cmake.bbclass b/meta/classes/cmake.bbclass
index 94ed8061bb..8243f7ce8c 100644
--- a/meta/classes/cmake.bbclass
+++ b/meta/classes/cmake.bbclass
@@ -70,15 +70,22 @@ CMAKE_BUILD_PARALLEL_LEVEL_task-install = "${@oe.utils.parallel_make(d, True)}"
 OECMAKE_TARGET_COMPILE ?= "all"
 OECMAKE_TARGET_INSTALL ?= "install"
 
+def map_host_os_to_system_name(host_os):
+    if host_os.startswith('mingw'):
+        return 'Windows'
+    if host_os.startswith('linux'):
+        return 'Linux'
+    return host_os
+
 # CMake expects target architectures in the format of uname(2),
 # which do not always match TARGET_ARCH, so all the necessary
 # conversions should happen here.
-def map_target_arch_to_uname_arch(target_arch):
-    if target_arch == "powerpc":
+def map_host_arch_to_uname_arch(host_arch):
+    if host_arch == "powerpc":
         return "ppc"
-    if target_arch == "powerpc64":
+    if host_arch == "powerpc64":
         return "ppc64"
-    return target_arch
+    return host_arch
 
 cmake_do_generate_toolchain_file() {
 	if [ "${BUILD_SYS}" = "${HOST_SYS}" ]; then
@@ -88,8 +95,8 @@ cmake_do_generate_toolchain_file() {
 # CMake system name must be something like "Linux".
 # This is important for cross-compiling.
 $cmake_crosscompiling
-set( CMAKE_SYSTEM_NAME `echo ${TARGET_OS} | sed -e 's/^./\u&/' -e 's/^\(Linux\).*/\1/'` )
-set( CMAKE_SYSTEM_PROCESSOR ${@map_target_arch_to_uname_arch(d.getVar('TARGET_ARCH'))} )
+set( CMAKE_SYSTEM_NAME ${@map_host_os_to_system_name(d.getVar('HOST_OS'))} )
+set( CMAKE_SYSTEM_PROCESSOR ${@map_host_arch_to_uname_arch(d.getVar('HOST_ARCH'))} )
 set( CMAKE_C_COMPILER ${OECMAKE_C_COMPILER} )
 set( CMAKE_CXX_COMPILER ${OECMAKE_CXX_COMPILER} )
 set( CMAKE_C_COMPILER_LAUNCHER ${OECMAKE_C_COMPILER_LAUNCHER} )
-- 
2.27.0