Experimental support LLVM ThinLTO. ThinLTO is a Link Time Opimization strategy, where the inlining step operates on LLVM intermediate code, and is sharded across multiple compiler invocations, so they can be parallelized. For more information, see http://llvm.org/devmtg/2015-04/slides/ThinLTO_EuroLLVM2015.pdf Using this features requires an experimental LLVM toolchain, with the following stanza in CROSSTOOL feature { name: "thin_lto" flag_set { action: "c-compile" action: "c++-compile" flag_group { flag: "-Xclang-only=-Wno-inconsistent-missing-override" flag: "-flto" flag: "-O2" } } } -- MOS_MIGRATED_REVID=100269776
{Fast, Correct} - Choose two
Bazel is a build tool that builds code quickly and reliably. It is used to build the majority of Google‘s software, and thus it has been designed to handle build problems present in Google’s development environment, including:
A massive, shared code repository, in which all software is built from source. Bazel has been built for speed, using both caching and parallelism to achieve this. Bazel is critical to Google's ability to continue to scale its software development practices as the company grows.
An emphasis on automated testing and releases. Bazel has been built for correctness and reproducibility, meaning that a build performed on a continuous build machine or in a release pipeline will generate bitwise-identical outputs to those generated on a developer's machine.
Language and platform diversity. Bazel's architecture is general enough to support many different programming languages within Google, and can be used to build both client and server software targeting multiple architectures from the same underlying codebase.
Find more background about Bazel in our FAQ.