{ "toolchain":
  { "type": "configure"
  , "arguments_config": ["ARCH", "BUILD_ARCH"]
  , "config":
    { "type": "singleton_map"
    , "key": "BUILD_ARCH"
    , "value":
      { "type": "var"
      , "name": "BUILD_ARCH"
      , "default":
        { "type": "var"
        , "name": "ARCH"
        , "default":
          {"type": "fail", "msg": "ARCH is required for cross-compiler."}
        }
      }
    }
  , "target": "toolchain_cross"
  }
, "toolchain_cross":
  { "type": "export"
  , "flexible_config":
    ["ARCH", "TARGET_ARCH", "BUILD_ARCH", "TOOLCHAIN_CONFIG", "ENV"]
  , "target": "gcc-musl-static"
  }
, "runlibs":
  { "type": "export"
  , "flexible_config": ["ARCH", "TARGET_ARCH", "TOOLCHAIN_CONFIG", "ENV"]
  , "target": "libgcc_s"
  }
, "gcc-musl-static":
  { "type": ["@", "rules", "CC/foreign/shell", "data"]
  , "project": [["@", "gcc-musl", "", "combined_patched_sources"]]
  , "arguments_config": ["BUILD_ARCH"]
  , "cmds":
    { "type": "let*"
    , "bindings":
      [ [ "TARGET"
        , { "type": "case"
          , "expr":
            { "type": "var"
            , "name": "BUILD_ARCH"
            , "default": {"type": "fail", "msg": "BUILD_ARCH is missing."}
            }
          , "case":
            { "x86": "i686"
            , "x86_64": "x86_64"
            , "arm": "arm"
            , "arm64": "aarch64"
            }
          , "default":
            { "type": "fail"
            , "msg":
              ["Unsupported BUILD_ARCH", {"type": "var", "name": "BUILD_ARCH"}]
            }
          }
        ]
      ]
    , "body":
      [ { "type": "join"
        , "$1": ["TARGET=", {"type": "var", "name": "TARGET"}, "-linux-musl"]
        }
      , "export NJOBS=$(nproc --all 2>/dev/null || echo 1)"
      , "export MAKEINFO=missing"
      , "unset CFLAGS CXXFLAGS LDFLAGS"
      , "printf '#!/bin/sh\\nexec \"%s\" -static \"$@\"' \"${CC}\" >${TMPDIR}/cc"
      , "printf '#!/bin/sh\\nexec \"%s\" -static \"$@\"' \"${CXX}\" >${TMPDIR}/c++"
      , "chmod +x ${TMPDIR}/cc ${TMPDIR}/c++"
      , "mv musl-latest.orig musl.readonly"
      , "cp -r musl.readonly musl-latest.orig && chmod -R +w musl-latest.orig"
      , "export check_msgfmt=no   # do not use system's msgfmt, if available"
      , "${MAKE} -j${NJOBS} TARGET=${TARGET} CC=${TMPDIR}/cc CXX=${TMPDIR}/c++ LDFLAGS='-static' LDFLAGS_FOR_TARGET='-static' >build.log 2>&1 || (cat build.log && exit 1)"
      , "${MAKE} -j${NJOBS} TARGET=${TARGET} CC=${TMPDIR}/cc CXX=${TMPDIR}/c++ LDFLAGS='-static' LDFLAGS_FOR_TARGET='-static' OUTPUT= DESTDIR=${DESTDIR} install >>build.log 2>&1 || (cat build.log && exit 1)"
      , "cd ${DESTDIR}"
      , "TARGET_STRIP=./bin/${TARGET}-strip"
      , "find ./bin/ ./${TARGET}/bin/ ./libexec/gcc/ -type f -exec sh -c \"strip {} 2>/dev/null\" \\;"
      , "find . -type f -name '*.so*' -exec sh -c \"${TARGET_STRIP} {} 2>/dev/null\" \\;"
      , "find . -type f -name '*.a' -exec sh -c \"${TARGET_STRIP} -g {}\" \\;"
      , "find . -type f -name '*.o' -exec sh -c \"${TARGET_STRIP} -g {}\" \\;"
      , "for f in $(ls ./bin/${TARGET}-*); do"
      , "  cp -l $f $(echo $f | sed 's|/'${TARGET}-'|/|g')"
      , "done"
      , "cp -rl ./${TARGET}/lib/. ./lib/."
      , "find . -type l ! -exec test -e {} \\; -delete"
      ]
    }
  , "out_dirs": ["."]
  }
, "toolchain_for_target":
  { "type": "configure"
  , "arguments_config": ["ARCH", "TARGET_ARCH"]
  , "config":
    { "type": "singleton_map"
    , "key": "BUILD_ARCH"
    , "value":
      { "type": "var"
      , "name": "TARGET_ARCH"
      , "default":
        { "type": "var"
        , "name": "ARCH"
        , "default":
          {"type": "fail", "msg": "ARCH is required for cross-compiler."}
        }
      }
    }
  , "target": "toolchain_cross"
  }
, "libgcc_s":
  { "type": ["@", "rules", "CC/prebuilt", "library"]
  , "name": ["libgcc"]
  , "lib": ["libgcc_s_files"]
  }
, "libgcc_s_files":
  { "type": "generic"
  , "arguments_config": ["ENV"]
  , "deps": ["toolchain_for_target"]
  , "cmds": [":"]
  , "outs": ["lib/libgcc_s.so.1"]
  , "env": {"type": "var", "name": "ENV", "default": {"type": "empty_map"}}
  }
}