What is cargo build-bpf?

Question

The solana-program-library says to build apps with cargo build-bpf yet if you look at cargo --help this is not mentioned as a valid argument. How does cargo know to look at BPF SDK: /home/phil/Downloads/solana-1.10.8/bin/sdk/bpf Why don't you build with cargo b like most Rust apps.

Answer 1

cargo --list does contain the build-bpf

It is a cargo tool that is a super set of build. What is does is take the LLVM output of build (i.e. rustc) and transpiles it into BPF which is the acceptable form for a Solana program to run on the chain.