Fix Clang build on Android.

build/android/envsetup.sh

Index: build/android/envsetup.sh
diff --git a/build/android/envsetup.sh b/build/android/envsetup.sh
index b0024858d70492f11ba2de8a541d7c71341a9f03..10e69f6a4b5d59d5838c0b02945ae713928f0fe7 100755
--- a/build/android/envsetup.sh
+++ b/build/android/envsetup.sh
@@ -104,7 +104,23 @@ export AR_target=$(echo -n ${ANDROID_TOOLCHAIN}/*-ar)
 # Performs a gyp_chromium run to convert gyp->Makefile for android code.
 android_gyp() {
   echo "GYP_GENERATORS set to '$GYP_GENERATORS'"
-  "${CHROME_SRC}/build/gyp_chromium" --depth="${CHROME_SRC}" --check "$@"
+  # http://crbug.com/143889.
+  # In case we are doing a Clang build, we have to unset CC_target and
+  # CXX_target. Otherwise GYP ends up generating a gcc build (although we set
+  # 'clang' to 1). This behavior was introduced by
+  # 54d2f6fe6d8a7b9d9786bd1f8540df6b4f46b83f in GYP.
+  (
+    # Fork to avoid side effects on the user's environment variables.
+    if echo "$GYP_DEFINES" | tr ' ' '\n' | grep -q '^clang=' | tail -n1 | \
+        grep -xq clang=1; then
+      if echo "$CC_target" | grep -q gcc; then
+        unset AR_target

[Yaron, 2012/09/04 17:16:19]

Note that I'm actually planning to remove the *_target declarations from
envsetup at some point in the near future. At least for make/ninja they're not
necessary anymore except for one place in v8. If we can clean that up then we
don't need to set or unset these as and can rely on gyp for everything. As this
is temporary, it seems reasonable for now. (also if you want to fix the
underlying issue let me know and I can point you at it :)

[Philippe, 2012/09/05 15:23:24]

Yes that sounds good, please assign the underlying bug to me :). For now let's
keep this (with the approach suggested by Sam).

+        unset CC_target
+        unset CXX_target
+      fi
+    fi
+    "${CHROME_SRC}/build/gyp_chromium" --depth="${CHROME_SRC}" --check "$@"
+  )
 }
 
 # FLOCK needs to be null on system that has no flock