port_compiler

A port compiler for rebar3.

This plugin is intended to replicate the rebar2 support for compiling native code. It is not a drop-in replacement in terms of command-line interface but the exact configuration interface in projects' rebar.configs have been preserved.

Use In Your Project

Add the plugin to your rebar.config:

{plugins, [pc]}.
{provider_hooks,
 [
  {pre,
   [
    {compile, {pc, compile}},
    {clean, {pc, clean}}
   ]
  }
 ]
}.

If you want to use tools like clang-tidy, don't forget to enable the compile commands db like this:

{pc_clang_db, true}.

From your existing application:

$ rebar3 pc compile
===> Fetching pc
===> Compiling pc
===> Verifying dependencies...
Compiling ...

You should now have native code compiled.

Use with Existing Dependency

If your project depends on a dependency that used the rebar2 port compiler instead of forking and changing the rebar.config of that dependency you can use overrides to inject the changes from your top level rebar.config. Using jiffy as an example:

{deps, [jiffy]}.

{overrides,
 [{override, jiffy, [
     {plugins, [pc]},
     {artifacts, ["priv/jiffy.so"]},
     {provider_hooks, [
         {post,
             [
             {compile, {pc, compile}},
             {clean, {pc, clean}}
             ]
          }]
      }
  ]}
]}.

Example

Looking for an example? See my fork of jiffy here and the changes to its rebar.config: https://github.com/blt/jiffy/commit/d4a0103daec5a646e71045bdf40f12a3eb82ace5

---

BELOW HERE BE DRAGONS

%% Supported configuration variables:
%%
%% * port_specs - Erlang list of tuples of the forms
%%                {ArchRegex, TargetFile, Sources, Options}
%%                {ArchRegex, TargetFile, Sources}
%%                {TargetFile, Sources}
%%
%%                Note that if you want to use any of the rebar3 variables
%%                below you must MUST use a ${}-style to get the expansion
%%                to work. e.g. to expand REBAR_DEPS_DIR, do something like:
%%
%%                {port_specs, [{"priv/nif.so",
%%                               ["c_src/nif.c",
%%                                "${REBAR_DEPS_DIR}/foo/bar.c"]}]}.
%%
%%                This is a _very_ good way to be able to use your code both
%%                as a top level app and a dependency.
%%
%%                CAVEAT! Not using {} is broken for the moment.
%%
%% * port_env - Erlang list of key/value pairs which will control
%%              the environment when running the compiler and linker.
%%              Variables set in the surrounding system shell are taken
%%              into consideration when expanding port_env. Note that
%%              for ERL_LDFLAGS, -lerl_interface is used for only those
%%              Erlang/OTP versions where it exists (those prior to
%%              version 23.0).
%%
%%              By default, the following variables are defined:
%%              CC       - C compiler
%%              CXX      - C++ compiler
%%              CFLAGS   - C compiler
%%              CXXFLAGS - C++ compiler
%%              LDFLAGS  - Link flags
%%              ERL_CFLAGS  - default -I paths for erts and ei
%%              ERL_LDFLAGS - default -L and -lerl_interface -lei
%%              DRV_CFLAGS  - flags that will be used for compiling
%%              DRV_LDFLAGS - flags that will be used for linking
%%              EXE_CFLAGS  - flags that will be used for compiling
%%              EXE_LDFLAGS - flags that will be used for linking
%%              ERL_EI_LIBDIR - ei library directory
%%              DRV_CXX_TEMPLATE      - C++ command template
%%              DRV_CC_TEMPLATE       - C command template
%%              DRV_LINK_TEMPLATE     - C Linker command template
%%              DRV_LINK_CXX_TEMPLATE - C++ Linker command template
%%              EXE_CXX_TEMPLATE      - C++ command template
%%              EXE_CC_TEMPLATE       - C command template
%%              EXE_LINK_TEMPLATE     - C Linker command template
%%              EXE_LINK_CXX_TEMPLATE - C++ Linker command template
%%
%%              Note that if you wish to extend (vs. replace) these variables,
%%              you MUST include a shell-style reference in your definition.
%%              e.g. to extend CFLAGS, do something like:
%%
%%              {port_env, [{"CFLAGS", "$CFLAGS -MyOtherOptions"}]}
%%
%%              It is also possible to specify platform specific options
%%              by specifying a triplet where the first string is a regex
%%              that is checked against Erlang's system architecture string.
%%              e.g. to specify a CFLAG that only applies to x86_64 on linux
%%              do:
%%
%%              {port_env, [{"x86_64.*-linux", "CFLAGS",
%%                           "$CFLAGS -X86Options"}]}
%%
%%              Cross-arch environment variables to configure toolchain:
%%              GET_ARCH to set the tool chain name to use
%%              GET_ARCH_WORDSIZE (optional - to determine word size)"
%%              word size is 32
%%              GET_ARCH_VSN (optional - "
%%              l version of CC/CXX is requested),