diff --git a/README.md b/README.md index e37da3bedb..ae4309686a 100644 --- a/README.md +++ b/README.md @@ -94,15 +94,49 @@ sudo apt-get install bsdmainutils dwarfdump libc6-dev:i386 lib32gcc-10-dev libst ## How to use +
A classic way to use mold + On Unix, the linker command (which is usually `/usr/bin/ld`) is -invoked indirectly by `cc` (or `gcc` or `clang`), which is typically -in turn indirectly invoked by `make` or some other build system command. +invoked indirectly by the compiler driver (which is usually `cc`, +`gcc` or `clang`), which is typically in turn indirectly invoked by +`make` or some other build system command. + +If you can specify an additional command line option to your compiler +driver by modifying build system's config files, add one of the +following flags to use `mold` instead of `/usr/bin/ld`: -A classic way to use `mold`: +- clang before 12.0: pass `-fuse-ld=`; -- `clang` before 12.0: pass `-fuse-ld=`; - clang after 12.0: pass `--ld-path=`; -- gcc: `--ld-path` patch [has been declined by GCC maintainers](https://gcc.gnu.org/pipermail/gcc-patches/2021-June/573833.html), instead they advise to use a [workaround](https://gcc.gnu.org/pipermail/gcc-patches/2021-June/573823.html): create directory ``, then `ln -s /ld`, and then pass `-B` (`-B` tells GCC to look for `ld` in specified location). + +- gcc: `--ld-path` patch [has been declined by GCC + maintainers](https://gcc.gnu.org/pipermail/gcc-patches/2021-June/573833.html), + instead they advise to use a + [workaround](https://gcc.gnu.org/pipermail/gcc-patches/2021-June/573823.html): + create directory ``, then `ln -s + /ld`, and then pass `-B` (`-B` tells GCC to look + for `ld` in specified location). + +
+ +
If you are using Rust + +Create `.cargo/config.toml` in your project with the following: + +``` +[target.x86_64-unknown-linux-gnu] +linker = "clang" +rustflags = ["-C", "link-arg=-fuse-ld=/path/to/mold"] +``` + +where `/path/to/mold` is an absolute path to `mold` exectuable. + +If you want to use mold for all projects, put the above snippet to +`~/.cargo/config.toml`. + +
+ +
mold -run It is sometimes very hard to pass an appropriate command line option to `cc` to specify an alternative linker. To deal with the situation, @@ -126,6 +160,8 @@ variable set to its companion shared object file. The shared object file intercepts all function calls to `exec(3)`-family functions to replace `argv[0]` with `mold` if it is `ld`, `ld.gold` or `ld.lld`. +
+ mold leaves its identification string in `.comment` section in an output file. You can print it out to verify that you are actually using mold.