Support cross-builds and alternative compilers with GN

Adds GN versions of the gyp_configure targets, to create custom
toolchains we can use to override compilers used by GN.

Change-Id: Ic3a9cb7e83f845180396faff632f72f9c24f3365
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

1 files changed, 48 insertions, 0 deletions

diff --git a/src/buildtools/configure_host.pro b/src/buildtools/configure_host.pro
new file mode 100644
index 000000000..217fad775
--- /dev/null
+++ b/src/buildtools/configure_host.pro
@@ -0,0 +1,48 @@
+# Prevent generating a makefile that attempts to create a lib
+TEMPLATE = aux
+
+# Pick up the host toolchain
+option(host_build)
+
+GN_TARGET_CPU = $$gnArch($$QT_ARCH)
+GN_CPU = $$gnArch($$QMAKE_HOST.arch)
+GN_OS = $$gnOS()
+
+clang: GN_CLANG = true
+else: GN_CLANG = false
+
+# We always use the gcc_toolchain, because clang_toolchain is just
+# a broken wrapper around it for Google's custom clang binaries.
+GN_CONTENTS = \
+"import(\"//build/config/sysroot.gni\")" \
+"import(\"//build/toolchain/gcc_toolchain.gni\")" \
+"gcc_toolchain(\"host\") {" \
+"  cc = \"$$which($$QMAKE_CC)\" " \
+"  cxx = \"$$which($$QMAKE_CXX)\" " \
+"  ld = \"$$which($$QMAKE_LINK)\" " \
+"  ar = \"$$which(ar)\" " \
+"  nm = \"$$which(nm)\" " \
+"  toolchain_args = { " \
+"    current_os = \"$$GN_OS\" " \
+"    current_cpu = \"$$GN_CPU\" " \
+"  } " \
+"}" \
+"gcc_toolchain(\"v8_snapshot\") {" \
+"  cc = \"$$which($$QMAKE_CC)\" " \
+"  cxx = \"$$which($$QMAKE_CXX)\" " \
+"  ld = \"$$which($$QMAKE_LINK)\" " \
+"  ar = \"$$which(ar)\" " \
+"  nm = \"$$which(nm)\" " \
+"  toolchain_args = { " \
+"    current_os = \"$$GN_OS\" " \
+"    current_cpu = \"$$GN_CPU\" " \
+"    v8_current_cpu = \"$$GN_TARGET_CPU\" " \
+"  } " \
+"}"
+
+
+
+GN_FILE = $$OUT_PWD/../toolchain/BUILD.gn
+!build_pass {
+    write_file($$GN_FILE, GN_CONTENTS)
+}