{ "defaults":
  { "doc":
    [ "A rule to provide defaults."
    , "All CC targets take their defaults for CXX, CC, flags, etc from"
    , "the target [\"CC\", \"defaults\"]. This is probably the only sensibe"
    , "use of this rule. As targets form a different root, the defaults"
    , "can be provided without changing this directory."
    ]
  , "string_fields": ["CC", "CXX", "CFLAGS", "CXXFLAGS", "PATH", "AR"]
  , "expression":
    { "type": "RESULT"
    , "provides":
      { "type": "map_union"
      , "$1":
        [ { "type": "singleton_map"
          , "key": "CC"
          , "value": {"type": "FIELD", "name": "CC"}
          }
        , { "type": "singleton_map"
          , "key": "CXX"
          , "value": {"type": "FIELD", "name": "CXX"}
          }
        , { "type": "singleton_map"
          , "key": "CFLAGS"
          , "value": {"type": "FIELD", "name": "CFLAGS"}
          }
        , { "type": "singleton_map"
          , "key": "CXXFLAGS"
          , "value": {"type": "FIELD", "name": "CXXFLAGS"}
          }
        , { "type": "singleton_map"
          , "key": "AR"
          , "value": {"type": "FIELD", "name": "AR"}
          }
        , { "type": "singleton_map"
          , "key": "ENV"
          , "value":
            { "type": "singleton_map"
            , "key": "PATH"
            , "value":
              { "type": "join"
              , "separator": ":"
              , "$1": {"type": "FIELD", "name": "PATH"}
              }
            }
          }
        ]
      }
    }
  }
, "configure":
  { "doc":
    [ "A rule to provide a static platform configuration for a target."
    , "The artifacts and runfiles of the specified target will be propagated."
    , "The target defined by this rule does not propagate any provides data."
    ]
  , "config_fields": ["os", "arch", "target_arch"]
  , "target_fields": ["target"]
  , "field_doc":
    { "os": ["The operation system used for building."]
    , "arch": ["The architecture used for building."]
    , "target_arch":
      [ "Non-mandatory target architecture to build for. If omitted, target"
      , "architecture is derived from \"arch\"."
      ]
    , "target":
      [ "The target to configure. Multiple targets are supported, but their"
      , "artifacts and runfiles should not conflict."
      ]
    }
  , "imports":
    { "transition": "configure transition"
    , "artifacts": ["./", "..", "field_artifacts"]
    , "runfiles": ["./", "..", "field_runfiles"]
    }
  , "config_transitions":
    {"target": [{"type": "CALL_EXPRESSION", "name": "transition"}]}
  , "expression":
    { "type": "let*"
    , "bindings":
      [ ["fieldname", "target"]
      , ["transition", {"type": "CALL_EXPRESSION", "name": "transition"}]
      ]
    , "body":
      { "type": "RESULT"
      , "artifacts": {"type": "CALL_EXPRESSION", "name": "artifacts"}
      , "runfiles": {"type": "CALL_EXPRESSION", "name": "runfiles"}
      }
    }
  }
, "header directory":
  { "doc":
    [ "A directory of header files."
    , ""
    , "Define a directory of  header files that belong together and are staged"
    , "in such a way that no other target (used together with this target) will"
    , "have to put files in this directory. The typical use case is a library"
    , "libfoo that expects all headers to be included as #include \"foo/bar.h\"."
    , "In this case, one would define a header direcotry for \"foo\"."
    , ""
    , "Technically, a tree is created from the given files and staged to the"
    , "specified location. Since trees are opaque, the directory name becomes"
    , "essentially owned by target. In this way, staging conflicts can be"
    , "avoided by detecting them early and not only once a file with the same"
    , "name is  added to the staging location. Also, as only a tree identifier"
    , "has to be passed around, such a directory can be handled more"
    , "efficiently by the tool."
    ]
  , "target_fields": ["hdrs"]
  , "string_fields": ["stage", "public stage"]
  , "field_doc":
    { "hdrs": ["The header files to be put into the header directory."]
    , "stage":
      [ "The location of the header directory."
      , "Path segments are joined with \"/\"."
      ]
    , "public stage":
      [ "If non-empty, no closure for the header directory's stage is created, "
      , "so can be combined with other header directories having the same "
      , "public staging directory."
      ]
    }
  , "expression":
    { "type": "let*"
    , "bindings":
      [ [ "hdrs"
        , { "type": "disjoint_map_union"
          , "$1":
            { "type": "foreach"
            , "var": "x"
            , "range": {"type": "FIELD", "name": "hdrs"}
            , "body":
              {"type": "DEP_RUNFILES", "dep": {"type": "var", "name": "x"}}
            }
          }
        ]
      , [ "stage"
        , { "type": "join"
          , "separator": "/"
          , "$1": {"type": "FIELD", "name": "stage"}
          }
        ]
      , [ "dir"
        , { "type": "if"
          , "cond": {"type": "FIELD", "name": "public stage"}
          , "then":
            { "type": "to_subdir"
            , "subdir": {"type": "var", "name": "stage"}
            , "$1": {"type": "var", "name": "hdrs"}
            }
          , "else":
            { "type": "singleton_map"
            , "key": {"type": "var", "name": "stage"}
            , "value": {"type": "TREE", "$1": {"type": "var", "name": "hdrs"}}
            }
          }
        ]
      ]
    , "body":
      { "type": "RESULT"
      , "artifacts": {"type": "var", "name": "dir"}
      , "runfiles": {"type": "var", "name": "dir"}
      }
    }
  }
, "library":
  { "doc": ["A C++ libaray"]
  , "target_fields": ["srcs", "hdrs", "private-hdrs", "deps", "proto"]
  , "string_fields":
    ["name", "stage", "pure C", "local defines", "link external"]
  , "config_vars": ["CXX", "CC", "CXXFLAGS", "CFLAGS", "ENV", "AR"]
  , "implicit": {"defaults": ["defaults"]}
  , "field_doc":
    { "name":
      ["The name of the library (without leading \"lib\" or trailing \".a\""]
    , "srcs": ["The source files of the library."]
    , "hdrs": ["Any public header files of the library."]
    , "private-hdrs":
      [ "Any header files that only need to be present when compiling the"
      , "source files, but are not needed for any consumer of the library"
      ]
    , "stage":
      [ "The logical location of all header and source files, as well as the"
      , "resulting library file. Individual directory components are joined"
      , "with \"/\"."
      ]
    , "pure C":
      [ "If non-empty, compile as C sources rathter than C++ sources."
      , "In particular, CC is used to compile rather than CXX"
      ]
    , "local defines":
      [ "List of defines set for source files local to this target."
      , "Each list entry will be prepended by \"-D\"."
      ]
    , "link external":
      ["Additional linker flags for linking external libraries."]
    , "deps": ["Any other libraries this library depends upon."]
    }
  , "config_doc":
    { "CXX": ["The name of the C++ compiler to be used."]
    , "CC":
      ["The name of the C compiler to be used (when compiling pure C code)"]
    , "AR": ["The archive tool to used for creating the library"]
    , "ENV": ["The environment for any action generated."]
    , "CXXFLAGS":
      [ "The flags for CXX to be used instead of the default ones."
      , "For libraries that should be built in a non-standard way; usually"
      , "adapting the default target [\"CC\", \"defaults\"] is the better"
      , "choice"
      ]
    , "CFLAGS":
      [ "The flags for CC to be used instead of the default ones."
      , "For libraries that should be built in a non-standard way; usually"
      , "adapting the default target [\"CC\", \"defaults\"] is the better"
      , "choice"
      ]
    }
  , "anonymous":
    { "proto-deps":
      { "target": "proto"
      , "provider": "proto"
      , "rule_map":
        { "library": ["./", "proto", "library"]
        , "service library": ["./", "proto", "service library"]
        }
      }
    }
  , "imports":
    { "artifacts": ["./", "..", "field_artifacts"]
    , "default-CXXFLAGS": "default-CXXFLAGS"
    , "default-CFLAGS": "default-CFLAGS"
    , "result": "lib result"
    }
  , "expression":
    { "type": "let*"
    , "bindings":
      [ [ "local defines"
        , { "type": "foreach"
          , "var": "def"
          , "range": {"type": "FIELD", "name": "local defines"}
          , "body":
            {"type": "join", "$1": ["-D", {"type": "var", "name": "def"}]}
          }
        ]
      , [ "CFLAGS"
        , { "type": "++"
          , "$1":
            [ { "type": "var"
              , "name": "CFLAGS"
              , "default":
                {"type": "CALL_EXPRESSION", "name": "default-CFLAGS"}
              }
            , {"type": "var", "name": "local defines"}
            ]
          }
        ]
      , [ "CXXFLAGS"
        , { "type": "++"
          , "$1":
            [ { "type": "var"
              , "name": "CXXFLAGS"
              , "default":
                {"type": "CALL_EXPRESSION", "name": "default-CXXFLAGS"}
              }
            , {"type": "var", "name": "local defines"}
            ]
          }
        ]
      , [ "stage"
        , { "type": "join"
          , "separator": "/"
          , "$1": {"type": "FIELD", "name": "stage"}
          }
        ]
      , [ "srcs"
        , { "type": "to_subdir"
          , "subdir": {"type": "var", "name": "stage"}
          , "$1":
            { "type": "let*"
            , "bindings": [["fieldname", "srcs"]]
            , "body": {"type": "CALL_EXPRESSION", "name": "artifacts"}
            }
          }
        ]
      , [ "hdrs"
        , { "type": "to_subdir"
          , "subdir": {"type": "var", "name": "stage"}
          , "$1":
            { "type": "let*"
            , "bindings": [["fieldname", "hdrs"]]
            , "body": {"type": "CALL_EXPRESSION", "name": "artifacts"}
            }
          }
        ]
      , [ "private-hdrs"
        , { "type": "to_subdir"
          , "subdir": {"type": "var", "name": "stage"}
          , "$1":
            { "type": "let*"
            , "bindings": [["fieldname", "private-hdrs"]]
            , "body": {"type": "CALL_EXPRESSION", "name": "artifacts"}
            }
          }
        ]
      , ["link external", {"type": "FIELD", "name": "link external"}]
      ]
    , "body": {"type": "CALL_EXPRESSION", "name": "result"}
    }
  }
, "binary":
  { "doc": ["A binary written in C++"]
  , "target_fields": ["srcs", "private-hdrs", "deps", "proto"]
  , "string_fields":
    ["name", "stage", "pure C", "local defines", "link external"]
  , "config_vars": ["CXX", "CC", "CXXFLAGS", "CFLAGS", "ENV"]
  , "implicit": {"defaults": ["defaults"]}
  , "field_doc":
    { "name": ["The name of the binary"]
    , "srcs": ["The source files of the library."]
    , "private-hdrs":
      [ "Any header files that need to be present when compiling the"
      , "source files."
      ]
    , "stage":
      [ "The logical location of all header and source files, as well as the"
      , "resulting binary file. Individual directory components are joined"
      , "with \"/\"."
      ]
    , "pure C":
      [ "If non-empty, compile as C sources rathter than C++ sources."
      , "In particular, CC is used to compile rather than CXX"
      ]
    , "local defines":
      [ "List of defines set for source files local to this target."
      , "Each list entry will be prepended by \"-D\"."
      ]
    , "link external":
      ["Additional linker flags for linking external libraries."]
    , "deps": ["Any other libraries this binary depends upon."]
    }
  , "config_doc":
    { "CXX": ["The name of the C++ compiler to be used."]
    , "CC":
      ["The name of the C compiler to be used (when compiling pure C code)"]
    , "ENV": ["The environment for any action generated."]
    , "CXXFLAGS":
      [ "The flags for CXX to be used instead of the default ones"
      , "taken from the [\"CC\", \"defaults\"] target"
      ]
    , "CFLAGS":
      [ "The flags for CXX to be used instead of the default ones"
      , "taken from the [\"CC\", \"defaults\"] target"
      ]
    }
  , "anonymous":
    { "proto-deps":
      { "target": "proto"
      , "provider": "proto"
      , "rule_map":
        { "library": ["./", "proto", "library"]
        , "service library": ["./", "proto", "service library"]
        }
      }
    }
  , "imports":
    { "artifacts": ["./", "..", "field_artifacts"]
    , "compile-deps": "compile-deps"
    , "link-deps": "link-deps"
    , "objects": "objects"
    , "default-CC": "default-CC"
    , "default-CXX": "default-CXX"
    , "default-CFLAGS": "default-CFLAGS"
    , "default-CXXFLAGS": "default-CXXFLAGS"
    , "default-ENV": "default-ENV"
    }
  , "expression":
    { "type": "let*"
    , "bindings":
      [ [ "local defines"
        , { "type": "foreach"
          , "var": "def"
          , "range": {"type": "FIELD", "name": "local defines"}
          , "body":
            {"type": "join", "$1": ["-D", {"type": "var", "name": "def"}]}
          }
        ]
      , [ "stage"
        , { "type": "join"
          , "separator": "/"
          , "$1": {"type": "FIELD", "name": "stage"}
          }
        ]
      , [ "srcs"
        , { "type": "to_subdir"
          , "subdir": {"type": "var", "name": "stage"}
          , "$1":
            { "type": "let*"
            , "bindings": [["fieldname", "srcs"]]
            , "body": {"type": "CALL_EXPRESSION", "name": "artifacts"}
            }
          }
        ]
      , [ "local hdrs"
        , { "type": "to_subdir"
          , "subdir": {"type": "var", "name": "stage"}
          , "$1":
            { "type": "let*"
            , "bindings": [["fieldname", "private-hdrs"]]
            , "body": {"type": "CALL_EXPRESSION", "name": "artifacts"}
            }
          }
        ]
      , [ "CXX"
        , { "type": "if"
          , "cond": {"type": "FIELD", "name": "pure C"}
          , "then":
            { "type": "var"
            , "name": "CC"
            , "default": {"type": "CALL_EXPRESSION", "name": "default-CC"}
            }
          , "else":
            { "type": "var"
            , "name": "CXX"
            , "default": {"type": "CALL_EXPRESSION", "name": "default-CXX"}
            }
          }
        ]
      , [ "CXXFLAGS"
        , { "type": "if"
          , "cond": {"type": "FIELD", "name": "pure C"}
          , "then":
            { "type": "var"
            , "name": "CFLAGS"
            , "default": {"type": "CALL_EXPRESSION", "name": "default-CFLAGS"}
            }
          , "else":
            { "type": "var"
            , "name": "CXXFLAGS"
            , "default":
              {"type": "CALL_EXPRESSION", "name": "default-CXXFLAGS"}
            }
          }
        ]
      , [ "CXXFLAGS"
        , { "type": "++"
          , "$1":
            [ {"type": "var", "name": "CXXFLAGS"}
            , {"type": "var", "name": "local defines"}
            ]
          }
        ]
      , [ "ENV"
        , { "type": "map_union"
          , "$1":
            { "type": "++"
            , "$1":
              [ {"type": "CALL_EXPRESSION", "name": "default-ENV"}
              , [ { "type": "var"
                  , "name": "ENV"
                  , "default": {"type": "empty_map"}
                  }
                ]
              ]
            }
          }
        ]
      , ["compile-deps", {"type": "CALL_EXPRESSION", "name": "compile-deps"}]
      , ["link-deps", {"type": "CALL_EXPRESSION", "name": "link-deps"}]
      , ["objects", {"type": "CALL_EXPRESSION", "name": "objects"}]
      , [ "base name"
        , {"type": "join", "$1": {"type": "FIELD", "name": "name"}}
        ]
      , [ "binary name"
        , { "type": "if"
          , "cond": {"type": "var", "name": "stage"}
          , "else": {"type": "var", "name": "base name"}
          , "then":
            { "type": "join"
            , "separator": "/"
            , "$1":
              [ {"type": "var", "name": "stage"}
              , {"type": "var", "name": "base name"}
              ]
            }
          }
        ]
      , [ "link-args"
        , { "type": "nub_right"
          , "$1":
            { "type": "++"
            , "$1":
              [ {"type": "keys", "$1": {"type": "var", "name": "objects"}}
              , { "type": "++"
                , "$1":
                  { "type": "foreach"
                  , "var": "dep"
                  , "range": {"type": "FIELD", "name": "deps"}
                  , "body":
                    { "type": "DEP_PROVIDES"
                    , "dep": {"type": "var", "name": "dep"}
                    , "provider": "link-args"
                    }
                  }
                }
              , {"type": "FIELD", "name": "link external"}
              ]
            }
          }
        ]
      , [ "binary"
        , { "type": "ACTION"
          , "outs": [{"type": "var", "name": "binary name"}]
          , "inputs":
            { "type": "disjoint_map_union"
            , "$1":
              [ {"type": "var", "name": "objects"}
              , {"type": "var", "name": "link-deps"}
              ]
            }
          , "cmd":
            { "type": "++"
            , "$1":
              [ [ {"type": "var", "name": "CXX"}
                , "-o"
                , {"type": "var", "name": "binary name"}
                ]
              , {"type": "var", "name": "link-args"}
              ]
            }
          , "env": {"type": "var", "name": "ENV"}
          }
        ]
      ]
    , "body":
      {"type": "RESULT", "artifacts": {"type": "var", "name": "binary"}}
    }
  }
}