Add android on windows build support

Add builds for android on windows platform. These
are required by qt release scripts to create armv7 targets
on windows.

Note new 'is_mingw' setting for toolchainis. This required
as andorid on windows build use mingw toolchain as a
host toolchian. Main gn_arg argument 'is_mingw' is used
only for target/default toolchian, in this case gn drops
toolchian_args. However toolchain_args are evaluated in
case of secondary/host toolchain.

Override v8 snapshot toolchain to avoid pulling windows
(msvc or clang) toolchains and creating yet another set of
toolchain targets.

Task-number: QTBUG-83459
Change-Id: I927872d69e363277b9f90c3adda28518d6b6bb13
Reviewed-by: Michael Brüning <michael.bruning@qt.io>

2 files changed, 25 insertions, 9 deletions

diff --git a/cmake/FindGn.cmake b/cmake/FindGn.cmake
index 3f25bb585..fd03b7346 100644
--- a/cmake/FindGn.cmake
+++ b/cmake/FindGn.cmake
@@ -7,10 +7,10 @@ endif()
 find_program(Gn_EXECUTABLE NAMES gn PATHS "${WEBENGINE_ROOT_BUILD_DIR}/install/bin" NO_DEFAULT_PATH)
 if(NOT QT_HOST_PATH STREQUAL "")
    find_program(Gn_EXECUTABLE NAMES gn PATHS ${QT_HOST_PATH}/${INSTALL_LIBEXECDIR} NO_DEFAULT_PATH)
-endif()
-# script mode does not have QT_HOST_PATH or INSTALL_LIBEXECDIR instead it uses QT_HOST_GN_PATH
-if(NOT QT_HOST_GN_PATH STREQUAL "")
-   find_program(Gn_EXECUTABLE NAMES gn PATHS ${QT_HOST_GN_PATH} NO_DEFAULT_PATH)
+   # note: mingw installs with INSTALL_LIBEXECDIR = bin,
+   # however android on windows has INSTALL_LIBEXECDIR = libexec,
+   # so cover this case also
+   find_program(Gn_EXECUTABLE NAMES gn PATHS ${QT_HOST_PATH}/${INSTALL_BINDIR} NO_DEFAULT_PATH)
 endif()
 find_program(Gn_EXECUTABLE NAMES gn)
 
diff --git a/cmake/Functions.cmake b/cmake/Functions.cmake
index 9fb4299c5..039b4daf7 100644
--- a/cmake/Functions.cmake
+++ b/cmake/Functions.cmake
@@ -717,6 +717,15 @@ function(get_gn_is_clang result)
     endif()
 endfunction()
 
+
+function(get_gn_is_mingw result)
+    if(MINGW)
+        set(${result} "true" PARENT_SCOPE)
+    else()
+        set(${result} "false" PARENT_SCOPE)
+    endif()
+endfunction()
+
 function(get_ios_sysroot result arch)
     if(NOT CMAKE_APPLE_ARCH_SYSROOTS)
       message(FATAL_ERROR "CMAKE_APPLE_ARCH_SYSROOTS not set.")
@@ -734,6 +743,7 @@ function(configure_gn_toolchain name binTargetCpu v8TargetCpu toolchainIn toolch
     set(GN_TOOLCHAIN ${name})
     get_gn_os(GN_OS)
     get_gn_is_clang(GN_IS_CLANG)
+    get_gn_is_mingw(GN_IS_MINGW)
     get_gn_arch(GN_CPU ${binTargetCpu})
     get_gn_arch(GN_V8_CPU ${v8TargetCpu})
     configure_file(${toolchainIn} ${toolchainOut}/BUILD.gn @ONLY)
@@ -1086,6 +1096,14 @@ macro(append_toolchain_setup)
     endif()
     if(ANDROID)
         list(APPEND gnArgArg target_os="android")
+        if(CMAKE_HOST_WIN32)
+            list(APPEND gnArgArg
+                host_toolchain="/${buildDir}/host_toolchain:host"
+                host_cpu="x64"
+                v8_snapshot_toolchain="/${buildDir}/v8_toolchain:v8"
+                target_cpu="${cpu}"
+            )
+        endif()
     endif()
 endmacro()
 
@@ -1234,17 +1252,15 @@ function(add_gn_command)
     endforeach()
     list(TRANSFORM output PREPEND "${arg_BUILDDIR}/")
 
-    if(QT_HOST_PATH)
-      set(QT_HOST_GN_PATH ${QT_HOST_PATH}/${INSTALL_LIBEXECDIR})
-    endif()
-
     add_custom_command(
         OUTPUT ${output}
         COMMAND ${CMAKE_COMMAND}
              -DBUILD_DIR=${arg_BUILDDIR}
              -DSOURCE_DIR=${CMAKE_CURRENT_LIST_DIR}
              -DMODULE=${arg_MODULE}
-             -DQT_HOST_GN_PATH=${QT_HOST_GN_PATH}
+             -DQT_HOST_PATH=${QT_HOST_PATH}
+             -DINSTALL_LIBEXECDIR=${INSTALL_LIBEXECDIR}
+             -DINSTALL_BINDIR=${INSTALL_BINDIR}
              -DPython3_EXECUTABLE=${Python3_EXECUTABLE}
              -DGN_THREADS=$ENV{QTWEBENGINE_GN_THREADS}
              -DQT_ALLOW_SYMLINK_IN_PATHS=${QT_ALLOW_SYMLINK_IN_PATHS}