A few words on sofort's tool-finding logic ========================================== # the goals of sofort's tool-finding logic are: - follow a clear, transparent, and consistent logic - allow users to easily specify per-build preferences - allow distros to easily and cleanly use site-wide settings # three-way terminology: - native machine: where make(1) will be running. - host machine: where the package's program or libraries will execute. - target machine: where code generated by the host package will execute. ! NOTE, however, that the host/target distinction is only relevant when building a code-generating utility (e.g. a compiler), and that the two are otherwise rather synonymous. Moreover, in practice it is much more common to see configure scripts being invoked with a --target=<machine> argument specifying the host, than with a --host=<machine> argument. # invocation and names of binary tools: - agnostic names (ar, nm, objdump, ...) - branded names (llvm-ar, llvm-nm, llvm-objdump, ...) - machine-prefixed agnostic names (x86_64-nt64-midipix-ar, ...) - machine-prefixed branded names (x86_64-linux-gnu-gcc-ar, ...) - machine-specifying branded tools, as in llvm-ar --target=x86_64-linux. # cross-compilation: default search order: - machine-prefixed agnostic tools - machine-prefixed branded tools, starting with the prefix most commonly associated with the selected compiler (that is, ``gcc'' when using gcc, and ``llvm'' when using clang) - (machine-specifying) agnostic tools - (machine-speficying) branded tools, starting once again with the prefix most commonly associated with the selected compiler # native builds: default search order: - agnostic tools - machine-prefixed agnostic tools - machine-prefixed branded tools - branded tools # using an alternate search order: - --toolchain=<prefix> (e.g. --toolchain=llvm) --> search for tools that begin with <prefix> before searching for agnostic tools # restricting which tools may be searched: - --zealous --> only search for agnostic tools - --zealous=<prefix> --> only search for <prefix>-branded tools # per-tool overrides, by example of the ``ar'' tool: - AR=ar --> set AR to $(command -v ar) - AR=/path/to/ar --> set AR to the specified absolute path # host generated config file and variable names: - ccenv/host.mk - AR, NM, OBJDUMP, ... # native generated config file and variable names: - ccenv/native.mk - NATIVE_AR, NATIVE_NM, NATIVE_OBJDUMP, ... # distro: site-wide preferences - --ccenv=/path/to/site-specific/ccenv - use the above to create ccenv as a symlink to /path/to/site-specific/ccenv, and to accordingly skip configure's tool-finding step.