DragonTC is a build system for compiling custom clang toolchains. These toolchains contain the latest AOSP patches(where applicable) and things not included in AOSP clang, such as LTO and Gold plugins, Polly compiled and automatically linked into tools, improved krait optimizations (-mcpu=krait2), and annoying flags such as -Werror, -Wfatal-errors, and -Weverything internally disabled. DragonTC compilers are also built with -O3, -pthread, and -fopenmp in order to reduce compile time when used for ROMs.

###Why use custom Clang?

Google has been slowly moving away from GCC for a while now, so we believe that we should get ahead of the toolchain game and start now! Furthermore, AOSP modules that are compiled with clang can easily be optimized with the new LTO and Polly options.

###How do use DragonTC in AOSP? -OUT OF DATE-

• Either clone a prebuilt or build your own toolchain and place it in prebuilts/clang/linux-x86/host/your_version (3.7.1 is the prefered version)
• Change the version in build/core/clang/config.mk to reflect the directory you placed it in.
• Either clone ours, or cherry-pick our changes to prebuilts/ndk and frameworks/rs.
• [WIP] Cherry-pick our DragonTC support commit in build.