Add a way for CrOS toolchains to set custom flags for the nacl bootstrap.

build/toolchain/cros/BUILD.gn

Index: build/toolchain/cros/BUILD.gn
diff --git a/build/toolchain/cros/BUILD.gn b/build/toolchain/cros/BUILD.gn
index 9056f90f14e7f0e0bc024518992e43c0085253a9..4876eb2f857b273a0b84fd333fa4905bbeb8c12b 100644
--- a/build/toolchain/cros/BUILD.gn
+++ b/build/toolchain/cros/BUILD.gn
@@ -14,58 +14,64 @@ clang_toolchain("clang_target") {
   toolchain_os = "linux"
 }
 
-template("cros_target_toolchain") {
-  if (defined(invoker.use_debug_fission)) {
-    use_debug_fission = invoker.use_debug_fission
-  }
-  if (defined(invoker.use_gold)) {
-    use_gold = invoker.use_gold
+# This is the normal toolchain for most targets.
+gcc_toolchain("target") {
+  ar = cros_target_ar
+  cc = cros_target_cc
+  cxx = cros_target_cxx
+  ld = cxx
+  if (cros_target_ld != "") {
+    ld = cros_target_ld
   }
-  if (defined(invoker.use_sysroot)) {
-    use_sysroot = invoker.use_sysroot
+  if (cros_target_nm != "") {
+    nm = cros_target_nm
   }
-
-  gcc_toolchain(target_name) {
-    # These are args for the template.
-    ar = cros_target_ar
-    cc = cros_target_cc
-    cxx = cros_target_cxx
-    ld = cxx
-    if (cros_target_ld != "") {
-      ld = cros_target_ld
-    }
-    if (cros_target_nm != "") {
-      nm = cros_target_nm
-    }
-    if (cros_target_readelf != "") {
-      readelf = cros_target_readelf
-    }
-    extra_cflags = cros_target_extra_cflags
-    extra_cppflags = cros_target_extra_cppflags
-    extra_cxxflags = cros_target_extra_cxxflags
-    extra_ldflags = cros_target_extra_ldflags
-
-    # These are passed through as toolchain_args.
-    cc_wrapper = ""
-    is_clang = is_clang
-    toolchain_cpu = target_cpu
-    toolchain_os = "chromeos"
-
-    use_debug_fission = use_debug_fission
-    use_gold = use_gold
-    use_sysroot = use_sysroot
+  if (cros_target_readelf != "") {
+    readelf = cros_target_readelf
   }
-}
+  extra_cflags = cros_target_extra_cflags
+  extra_cppflags = cros_target_extra_cppflags
+  extra_cxxflags = cros_target_extra_cxxflags
+  extra_ldflags = cros_target_extra_ldflags
 
-# This is the normal toolchain for most targets.
-cros_target_toolchain("target") {
+  # These are passed through as toolchain_args.
+  cc_wrapper = ""
+  is_clang = is_clang
+  toolchain_cpu = target_cpu
+  toolchain_os = "chromeos"
+  use_debug_fission = use_debug_fission
+  use_gold = use_gold
+  use_sysroot = use_sysroot
 }
 
 # This is a special toolchain needed just for the nacl_bootstrap target in
 # //native_client/src/trusted/service_runtime/linux. It is identical
 # to ":target" except that it forces use_debug_fission, use_gold, and
 # use_sysroot off.
-cros_target_toolchain("nacl_bootstrap") {
+gcc_toolchain("nacl_bootstrap") {

[llozano1, 2016/07/28 17:20:56]

why the name change? does this mean this will not work when using the clang
compiler?

[Dirk Pranke, 2016/07/28 17:23:53]

No, it's fine. All I did was get rid of the template and expand the work the
template was doing, as there was less than 50% overlap between the two
toolchains with these changes.

The "clang_toolchain" template really just sets is_clang=true, and should go
away soon. This patch should not affect using clang or gcc.

[Dirk Pranke, 2016/08/01 20:53:09]

Actually, the clang_toolchain() template does two things:

1) sets is_clang=true

2) sets up the toolchain to point to the *chromium-built* version of clang (in
src/third_party/llvm-build).

I want to double-check before I land this: You have your own clang binaries, and
don't want to use the chromium-built ones, right?

+  ar = cros_target_ar
+  cc = cros_target_cc
+  cxx = cros_target_cxx
+  ld = cxx
+  if (cros_target_ld != "") {
+    ld = cros_target_ld
+  }
+  if (cros_target_nm != "") {
+    nm = cros_target_nm
+  }
+  if (cros_target_readelf != "") {
+    readelf = cros_target_readelf
+  }
+  extra_cflags = cros_nacl_bootstrap_extra_cflags
+  extra_cppflags = cros_nacl_bootstrap_extra_cppflags
+  extra_cxxflags = cros_nacl_bootstrap_extra_cxxflags
+  extra_ldflags = cros_nacl_bootstrap_extra_ldflags
+
+  # These are passed through as toolchain_args.
+  cc_wrapper = ""
+  is_clang = is_clang
+  toolchain_cpu = target_cpu
+  toolchain_os = "chromeos"
   use_debug_fission = false
   use_gold = false
   use_sysroot = false