On 14 November 2012 21:31, Michael Hope <michael.hope@linaro.org> wrote:
On 15 November 2012 02:23, Bernhard Rosenkränzer
<bernhard.rosenkranzer@linaro.org> wrote:
> "platform/prebuilts/clang/linux-x86/3.2", looks like someone is considering
> to move away from gcc. It'll be interesting to benchmark this against Linaro
> gcc (if llvm 2.9 is any indication, its optimization will come nowhere near
> ours - but of course they haven't been sitting around idle)

It could be used for Renderscript, a static checker, or many other
things apart from the static C compiler.  We'll see.

There's some odd stuff going on there...
They've added a new keyword to the Android.mk makefiles - you can now set

LOCAL_CLANG := true

in order to build a project with clang as opposed to whatever compiler is being provided.

Inside AOSP itself, LOCAL_CLANG is set for

frameworks/support/renderscript/v8/rs_support
frameworks/rs
external/compiler-rt
external/compiler-rt/lib
external/compiler-rt/lib/asan
external/libpng

That's renderscript related bits, compiler-rt (that library looks a lot like a libgcc replacement to me), and libpng.

At least libpng strikes me as something that could just as easily be built with gcc (and it was up until 4.1)
Looks like they force clang wherever they use -ftrapv -- maybe it's a workaround for a -ftrapv breakage in [their version of] gcc?

ttyl
bero