This file documents how to use clang as the C compiler with Mercury.
Support for Mercury with clang has been tested on Linux, macOS and Windows.
To use clang as the C compiler for Mercury invoke Mercury's configure
script with the --with-cc option set as follows:
$ ./configure --with-cc=clang
Note that the asm_fast* and reg* grades are not usable with clang as they
rely on GNU C extensions that clang does not provide.
Versions of LLVM (the underlying compiler infrastructure used by clang) before
about version 2.9 contain bugs that require most C compiler optimizations to be
disabled when compiling Mercury generated C code with clang (i.e. the
generated C files have to be compiled at -O0). If you are using a more recent
version of LLVM then the configure script will automatically enable a higher
level of optimization.