class Gem::Ext::CargoBuilder

This class is used by rubygems to build Rust extensions. It is a thin-wrapper over the ‘cargo rustc` command which takes care of building Rust code in a way that Ruby can use.

Attributes

profile[RW]
runner[RW]
spec[RW]

Public Class Methods

new(spec) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 9
def initialize(spec)
  require_relative "../command"
  require_relative "cargo_builder/link_flag_converter"

  @spec = spec
  @runner = self.class.method(:run)
  @profile = :release
end

Public Instance Methods

build(_extension, dest_path, results, args = [], lib_dir = nil, cargo_dir = Dir.pwd) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 18
def build(_extension, dest_path, results, args = [], lib_dir = nil, cargo_dir = Dir.pwd)
  require "fileutils"
  require "shellwords"

  build_crate(dest_path, results, args, cargo_dir)
  validate_cargo_build!(dest_path)
  rename_cdylib_for_ruby_compatibility(dest_path)
  finalize_directory(dest_path, lib_dir, cargo_dir)
  results
end
build_crate(dest_path, results, args, cargo_dir) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 29
def build_crate(dest_path, results, args, cargo_dir)
  env = build_env
  cmd = cargo_command(cargo_dir, dest_path, args)
  runner.call cmd, results, "cargo", cargo_dir, env

  results
end
build_env() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 37
def build_env
  build_env = rb_config_env
  build_env["RUBY_STATIC"] = "true" if ruby_static? && ENV.key?("RUBY_STATIC")
  build_env["RUSTFLAGS"] = "#{ENV["RUSTFLAGS"]} --cfg=rb_sys_gem".strip
  build_env
end
cargo_command(cargo_dir, dest_path, args = []) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 44
def cargo_command(cargo_dir, dest_path, args = [])
  manifest = File.join(cargo_dir, "Cargo.toml")
  cargo = ENV.fetch("CARGO", "cargo")

  cmd = []
  cmd += [cargo, "rustc"]
  cmd += ["--target", ENV["CARGO_BUILD_TARGET"]] if ENV["CARGO_BUILD_TARGET"]
  cmd += ["--target-dir", dest_path]
  cmd += ["--manifest-path", manifest]
  cmd += ["--lib"]
  cmd += ["--profile", profile.to_s]
  cmd += ["--locked"]
  cmd += Gem::Command.build_args
  cmd += args
  cmd += ["--"]
  cmd += [*cargo_rustc_args(dest_path)]
  cmd
end

Private Instance Methods

cargo_crate_name() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 155
def cargo_crate_name
  spec.metadata.fetch("cargo_crate_name", spec.name).tr("-", "_")
end
cargo_dylib_path(dest_path) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 147
def cargo_dylib_path(dest_path)
  prefix = so_ext == "dll" ? "" : "lib"
  path_parts = [dest_path]
  path_parts << ENV["CARGO_BUILD_TARGET"] if ENV["CARGO_BUILD_TARGET"]
  path_parts += ["release", "#{prefix}#{cargo_crate_name}.#{so_ext}"]
  File.join(*path_parts)
end
cargo_rustc_args(dest_dir) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 71
def cargo_rustc_args(dest_dir)
  [
    *linker_args,
    *mkmf_libpath,
    *rustc_dynamic_linker_flags(dest_dir),
    *rustc_lib_flags(dest_dir),
    *platform_specific_rustc_args(dest_dir),
  ]
end
darwin_target?() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 182
def darwin_target?
  makefile_config("target_os").include?("darwin")
end
final_extension_path(dest_path) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 141
def final_extension_path(dest_path)
  dylib_path = cargo_dylib_path(dest_path)
  dlext_name = "#{spec.name}.#{makefile_config("DLEXT")}"
  dylib_path.gsub(File.basename(dylib_path), dlext_name)
end
finalize_directory(dest_path, lib_dir, extension_dir) click to toggle source

Copied from ExtConfBuilder

# File lib/rubygems/ext/cargo_builder.rb, line 257
def finalize_directory(dest_path, lib_dir, extension_dir)
  require "fileutils"
  require "tempfile"

  ext_path = final_extension_path(dest_path)

  begin
    tmp_dest = Dir.mktmpdir(".gem.", extension_dir)

    # Some versions of `mktmpdir` return absolute paths, which will break make
    # if the paths contain spaces.
    #
    # As such, we convert to a relative path.
    tmp_dest_relative = get_relative_path(tmp_dest.clone, extension_dir)

    full_tmp_dest = File.join(extension_dir, tmp_dest_relative)

    # TODO: remove in RubyGems 4
    if Gem.install_extension_in_lib && lib_dir
      FileUtils.mkdir_p lib_dir
      FileUtils.cp_r ext_path, lib_dir, remove_destination: true
    end

    FileUtils::Entry_.new(full_tmp_dest).traverse do |ent|
      destent = ent.class.new(dest_path, ent.rel)
      destent.exist? || FileUtils.mv(ent.path, destent.path)
    end
  ensure
    FileUtils.rm_rf tmp_dest if tmp_dest
  end
end
get_relative_path(path, base) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 289
def get_relative_path(path, base)
  path[0..base.length - 1] = "." if path.start_with?(base)
  path
end
libruby_args(dest_dir) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 114
def libruby_args(dest_dir)
  libs = makefile_config(ruby_static? ? "LIBRUBYARG_STATIC" : "LIBRUBYARG_SHARED")
  raw_libs = Shellwords.split(libs)
  raw_libs.flat_map {|l| ldflag_to_link_modifier(l) }
end
linker_args() click to toggle source

We want to use the same linker that Ruby uses, so that the linker flags from mkmf work properly.

# File lib/rubygems/ext/cargo_builder.rb, line 105
def linker_args
  # Have to handle CC="cl /nologo" on mswin
  cc_flag = Shellwords.split(makefile_config("CC"))
  linker = cc_flag.shift
  link_args = cc_flag.flat_map {|a| ["-C", "link-arg=#{a}"] }

  ["-C", "linker=#{linker}", *link_args]
end
makefile_config(var_name) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 248
def makefile_config(var_name)
  val = RbConfig::MAKEFILE_CONFIG[var_name]

  return unless val

  RbConfig.expand(val.dup)
end
maybe_resolve_ldflag_variable(input_arg, dest_dir) click to toggle source

Interpolate substition vars in the arg (i.e. $(DEFFILE))

# File lib/rubygems/ext/cargo_builder.rb, line 196
def maybe_resolve_ldflag_variable(input_arg, dest_dir)
  var_matches = input_arg.match(/\$\((\w+)\)/)

  return input_arg unless var_matches

  var_name = var_matches[1]

  return input_arg if var_name.nil? || var_name.chomp.empty?

  case var_name
  # On windows, it is assumed that mkmf has setup an exports file for the
  # extension, so we have to to create one ourselves.
  when "DEFFILE"
    write_deffile(dest_dir)
  else
    RbConfig::CONFIG[var_name]
  end
end
mingw_target?() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 186
def mingw_target?
  makefile_config("target_os").include?("mingw")
end
mkmf_libpath() click to toggle source

Corresponds to $(LIBPATH) in mkmf

# File lib/rubygems/ext/cargo_builder.rb, line 244
def mkmf_libpath
  ["-L", "native=#{makefile_config("libdir")}"]
end
msvc_target?() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 178
def msvc_target?
  makefile_config("target_os").include?("msvc")
end
platform_specific_rustc_args(dest_dir, flags = []) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 81
def platform_specific_rustc_args(dest_dir, flags = [])
  if mingw_target?
    # On mingw platforms, mkmf adds libruby to the linker flags
    flags += libruby_args(dest_dir)

    # Make sure ALSR is used on mingw
    # see https://github.com/rust-lang/rust/pull/75406/files
    flags += ["-C", "link-arg=-Wl,--dynamicbase"]
    flags += ["-C", "link-arg=-Wl,--disable-auto-image-base"]

    # If the gem is installed on a host with build tools installed, but is
    # run on one that isn't the missing libraries will cause the extension
    # to fail on start.
    flags += ["-C", "link-arg=-static-libgcc"]
  elsif darwin_target?
    # Ventura does not always have this flag enabled
    flags += ["-C", "link-arg=-Wl,-undefined,dynamic_lookup"]
  end

  flags
end
rb_config_env() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 65
def rb_config_env
  result = {}
  RbConfig::CONFIG.each {|k, v| result["RBCONFIG_#{k}"] = v }
  result
end
rename_cdylib_for_ruby_compatibility(dest_path) click to toggle source

Ruby expects the dylib to follow a file name convention for loading

# File lib/rubygems/ext/cargo_builder.rb, line 127
def rename_cdylib_for_ruby_compatibility(dest_path)
  new_path = final_extension_path(dest_path)
  FileUtils.cp(cargo_dylib_path(dest_path), new_path)
  new_path
end
ruby_static?() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 120
def ruby_static?
  return true if %w[1 true].include?(ENV["RUBY_STATIC"])

  makefile_config("ENABLE_SHARED") == "no"
end
rustc_dynamic_linker_flags(dest_dir) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 159
def rustc_dynamic_linker_flags(dest_dir)
  split_flags("DLDFLAGS")
    .map {|arg| maybe_resolve_ldflag_variable(arg, dest_dir) }
    .compact
    .flat_map {|arg| ldflag_to_link_modifier(arg) }
end
rustc_lib_flags(dest_dir) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 166
def rustc_lib_flags(dest_dir)
  split_flags("LIBS").flat_map {|arg| ldflag_to_link_modifier(arg) }
end
so_ext() click to toggle source

We have to basically reimplement RbConfig::CONFIG here to support Ruby < 2.5

@see github.com/ruby/ruby/blob/c87c027f18c005460746a74c07cd80ee355b16e4/configure.ac#L3185

# File lib/rubygems/ext/cargo_builder.rb, line 231
def so_ext
  return RbConfig::CONFIG["SOEXT"] if RbConfig::CONFIG.key?("SOEXT")

  if win_target?
    "dll"
  elsif darwin_target?
    "dylib"
  else
    "so"
  end
end
split_flags(var) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 170
def split_flags(var)
  Shellwords.split(RbConfig::CONFIG.fetch(var, ""))
end
validate_cargo_build!(dir) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 133
def validate_cargo_build!(dir)
  dylib_path = cargo_dylib_path(dir)

  raise DylibNotFoundError, dir unless File.exist?(dylib_path)

  dylib_path
end
win_target?() click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 190
def win_target?
  target_platform = RbConfig::CONFIG["target_os"]
  !!Gem::WIN_PATTERNS.find {|r| target_platform =~ r }
end
write_deffile(dest_dir) click to toggle source
# File lib/rubygems/ext/cargo_builder.rb, line 215
def write_deffile(dest_dir)
  deffile_path = File.join(dest_dir, "#{spec.name}-#{RbConfig::CONFIG["arch"]}.def")
  export_prefix = makefile_config("EXPORT_PREFIX") || ""

  File.open(deffile_path, "w") do |f|
    f.puts "EXPORTS"
    f.puts "#{export_prefix.strip}Init_#{spec.name}"
  end

  deffile_path
end