-- CedarLinkerOps.mesa
-- Last edited by John Maxwell on: January 12, 1983 10:21 am

DIRECTORY
  Atom USING [GetProp, PutProp],
  BcdDefs USING [Link, NullVersion, VersionStamp],
  BcdOps USING [BcdBase, MTHandle],
  PilotLoadStateOps USING [Map],
  PrincOps USING [ControlLink, GFTIndex, GlobalFrameHandle],
  Rope USING [Text];
  
CedarLinkerOps: DEFINITIONS IMPORTS Atom =
  BEGIN OPEN BcdDefs, BcdOps, PrincOps, PilotLoadStateOps;
  
  IR: TYPE = REF IRRecord;
  IRRecord: TYPE = RECORD[s: SEQUENCE size: NAT OF PrincOps.ControlLink];
  
  Export: PROC[bcd: BcdBase, map: Map];
  
  Bind: PROC[bcd: BcdBase, map: Map] RETURNS[resolved: BOOLEAN];
  
  GetIR: PROCEDURE[ -- either the atom or the version must be non-NIL
     atom: ATOM _ NIL, 
     version: VersionStamp _ NullVersion, 
     length: CARDINAL _ 0] -- in case a new one must be created
     RETURNS[name: ATOM, interface: IR, versionStamp: VersionStamp];
  
  GetFrame: PROC[interface: IR, index: CARDINAL] RETURNS[GlobalFrameHandle];
  -- returns the frame of an exported variable
  
  NullLink: PROC[link: UNSPECIFIED] RETURNS[BOOLEAN] =
    INLINE BEGIN RETURN[
      LOOPHOLE[link, CARDINAL] = 0 OR -- PrincOps.NullLink
      LOOPHOLE[link, CARDINAL] = 1]; END; -- PrincOps.UnboundLink
  
  OpenLinkSpace: PROC[frame: GlobalFrameHandle, mth: MTHandle, bcd: BcdBase _ NIL];
  ReadLink: PROC[offset: CARDINAL] RETURNS [link: ControlLink];
  WriteLink: PROC[offset: CARDINAL, link: ControlLink];
  CloseLinkSpace: PROC[frame: GlobalFrameHandle];

  GetSpace: PROC[nwords: CARDINAL] RETURNS [p: POINTER];
  FreeSpace: PROC[p: POINTER];
  
  LinkSegmentLength: PROC[mth: MTHandle, bcd: BcdBase] RETURNS[CARDINAL];
  IthLink: PROC[mth: MTHandle, i: CARDINAL, bcd: BcdBase] RETURNS[Link];

  -- private definitions
  
  
  GetPendingList: PRIVATE PROC[interface: ATOM] RETURNS[PendingList] =
    INLINE {RETURN[NARROW[Atom.GetProp[interface, $pending]]]};
  SetPendingList: PRIVATE PROC[interface: ATOM, list: PendingList] =
    INLINE {Atom.PutProp[interface, $pending, list]};
  
  GetBinding: PROC[bcd: BcdBase] RETURNS[binding: Binding]; -- already filled in
  FindVariableLink: PROC[bcd: BcdBase, mthLink: Link, rgfi: PrincOps.GFTIndex]
    RETURNS [link: PrincOps.ControlLink, frame: PrincOps.GlobalFrameHandle];
    
  pendingModules: PRIVATE LIST OF PendingModule;
  -- list of people waiting for a MODULE to be exported
  
  Binding: TYPE = REF BindingSequence;
  BindingSequence: TYPE = RECORD[s: SEQUENCE size: NAT OF BindLink];
  -- A Binding is a mapping between the dummy gfi's within the bcd and real interfaces.
  -- Bindings are only legal for [bcd.firstdummy..bcd.firstdummy+bcd.nDummies) !
  BindLink: TYPE = RECORD[
    whichgfi: PrincOps.GFTIndex _ 0, -- if there is more than one gfi for this interface 
    atom: ATOM, -- so we can get and set the pending list
    interface: IR];
    
  PendingList: TYPE = LIST OF Pending;
  Pending: TYPE = RECORD[ -- frame, mth, and bcd are parameters to OpenLinkSpace
    frame: GlobalFrameHandle,
    mth: MTHandle,
    bcd: BcdBase,
    index: CARDINAL, -- index into the links area
    link: PrincOps.ControlLink]; -- either a) an index into the IR or b) the actual link
    
  PendingModule: TYPE = RECORD[ -- frame, mth, and bcd are parameters to OpenLinkSpace
    frame: PrincOps.GlobalFrameHandle, 
    mth: MTHandle, 
    bcd: BcdBase,
    index: CARDINAL, -- index into the links area
    name: Rope.Text, -- name of module we are waiting for
    version: BcdDefs.VersionStamp]; -- version of module we are waiting for
  
  END . .