<<>>
    <<BreakpointImpl.mesa>>
        <<Copyright Ó 1989, 1990 by Xerox Corporation.  All rights reserved.>>
        <<Peter B. Kessler, April 19, 1990 10:38 am PDT>>
    <<>>
        DIRECTORY
            TargetArchitecture,
            BreakWorldArchitecture,
            RefTab,
            Breakpoint,
            Shepherd,
            Rope;

BreakpointImpl: CEDAR PROGRAM 
    IMPORTS Breakpoint, RefTab, BreakWorldArchitecture
    EXPORTS Breakpoint, BreakWorldArchitecture
    ~ {
<<Public Types EXPORTed to BreakWorldArchitecture>>
    BreakAccess: PUBLIC TYPE ~ Breakpoint.BreakAccess _ Breakpoint.nullBreakAccess;
        BreakAccessRep: PUBLIC TYPE ~ Breakpoint.BreakAccessRep;

<<Public Types EXPORTed to Breakpoint>>
    BreakAccessData: PUBLIC TYPE ~ REF BreakAccessDataRep _ Breakpoint.nullBreakAccessData;
        BreakAccessDataRep: PUBLIC TYPE ~ RECORD [
            breakTable: RefTab.Ref _ NIL
            ];

    Break: PUBLIC TYPE ~ REF BreakRep _ Breakpoint.nullBreak;
        BreakRep: PUBLIC TYPE ~ RECORD [
            breakAccess: Breakpoint.BreakAccess,
            address: BreakWorldArchitecture.Address,
            patch: Shepherd.Patch,
            clientData: Breakpoint.ClientData
            ];

<<Public Procedures EXPORTed to Breakpoint>>
    NewBreakAccess: PUBLIC PROCEDURE [] 
    RETURNS [Breakpoint.BreakAccess] ~{
        procs: Breakpoint.BreakAccessProcs ~ NEW[Breakpoint.BreakAccessProcsRep _ [
            set: Breakpoint.SetBreakpoint, 
            clear: Breakpoint.ClearBreakpoint, 
            enumerate: Breakpoint.EnumerateBreakpoints]];
        data: Breakpoint.BreakAccessData ~ NEW[BreakAccessDataRep _ [
            breakTable: RefTab.Create[]]];
        breakAccess: Breakpoint.BreakAccess ~ NEW[Breakpoint.BreakAccessRep _ 
            [procs: procs, data: data]];

        RETURN [breakAccess];
        };

    EnumerateBreakpoints: PUBLIC Breakpoint.EnumerateBreakProc ~ {
        <<PROCEDURE [breakWorld: BreakWorldArchitecture.BreakWorld, proc: BreakpointProc] 
        RETURNS [quit: BOOLEAN _ FALSE];>>
        Apply: RefTab.EachPairAction ~ {
            <<PROC [key: Key, val: Val] RETURNS [quit: BOOL _ FALSE]>>
            break: Break ~ NARROW[val];
            clientData: Breakpoint.ClientData ~ Breakpoint.ClientDataFromBreak[break: break];

            quit _ proc[clientData: clientData];
            RETURN [quit: quit];
            };
        breakAccess: Breakpoint.BreakAccess ~ 
            BreakWorldArchitecture.BreakAccessFromBreakWorld[breakWorld: breakWorld];
        breakTable: RefTab.Ref ~ BreakTableFromBreakAccess[breakAccess: breakAccess];

        IF breakTable = NIL THEN {
            ERROR Breakpoint.Cant[
                code: $NullBreakTable, message: "EnumerateBreakpoints[nullBreakTable]"];
                };
        quit _ breakTable.Pairs[action: Apply];
        RETURN [quit: quit];
        };

    RememberBreak: PUBLIC PROCEDURE [break: Break] ~ {
        breakAccess: Breakpoint.BreakAccess ~ 
            BreakAccessFromBreak[break: break];
        breakTable: RefTab.Ref ~ BreakTableFromBreakAccess[breakAccess: breakAccess];

        IF breakTable = NIL THEN {
            ERROR Breakpoint.Cant[
                code: $NullBreakTable, message: "RememberBreak[nullBreakTable]"];
                };
        IF NOT breakTable.Insert[key: break, val: break] THEN {
            ERROR Breakpoint.Cant[code: $CantRememberBreak, message: "Can't remember break"];
            };
        RETURN;
        };

    ForgetBreak: PUBLIC PROCEDURE [break: Break] ~ {
        breakAccess: Breakpoint.BreakAccess ~ BreakAccessFromBreak[break: break];
        breakTable: RefTab.Ref ~ BreakTableFromBreakAccess[breakAccess: breakAccess];

        IF breakTable = NIL THEN {
            ERROR Breakpoint.Cant[
                code: $NullBreakTable, message: "ForgetBreak[nullBreakTable]"];
                };
        IF NOT breakTable.Delete[key: break] THEN {
            ERROR Breakpoint.Cant[code: $CantForgetBreak, message: "Can't forget break"];
            };
        RETURN;
        };

    NewBreak: PUBLIC PROCEDURE [
    address: BreakWorldArchitecture.Address,
    patch: Shepherd.Patch,
    clientData: Breakpoint.ClientData]
    RETURNS [Breakpoint.Break] ~ {
        breakWorld: BreakWorldArchitecture.BreakWorld ~ 
            BreakWorldArchitecture.BreakWorldFromBreakWorldAddress[address: address];
        breakAccess: Breakpoint.BreakAccess ~ 
            BreakWorldArchitecture.BreakAccessFromBreakWorld[breakWorld: breakWorld];
        break: Breakpoint.Break ~ NEW[BreakRep _ [
            breakAccess: breakAccess, address: address, patch: patch, clientData: clientData]];

        RETURN [break];
        };

    IsNullBreak: PUBLIC PROCEDURE [break: Breakpoint.Break] RETURNS [BOOLEAN] ~ {
        RETURN [break = Breakpoint.nullBreak];
        };

    AddressFromBreak: PUBLIC PROCEDURE [break: Breakpoint.Break] 
    RETURNS [BreakWorldArchitecture.Address] ~ {
        IF break.IsNullBreak[] THEN {
            ERROR Breakpoint.Cant[code: $NullBreak, message: "AddressFromBreak[nullBreak]"];
            };
        RETURN [break.address];
        };

    PatchFromBreak: PUBLIC PROCEDURE [break: Breakpoint.Break] 
    RETURNS [Shepherd.Patch] ~ {
        IF break.IsNullBreak[] THEN {
            ERROR Breakpoint.Cant[code: $NullBreak, message: "PatchFromBreak[nullBreak]"];
            };
        RETURN [break.patch];
        };

    ClientDataFromBreak: PUBLIC PROCEDURE [break: Breakpoint.Break] 
    RETURNS [Breakpoint.ClientData] ~ {
        IF break.IsNullBreak[] THEN {
            ERROR Breakpoint.Cant[code: $NullBreak, message: "ClientDataFromBreak[nullBreak]"];
            };
        RETURN [break.clientData];
        };

<<Private Procedures>>
    BreakAccessFromBreak: PROCEDURE [break: Break] RETURNS [Breakpoint.BreakAccess] ~ {
        IF Breakpoint.IsNullBreak[break: break] THEN {
            ERROR Breakpoint.Cant[
                code: $NullBreak, message: "BreakAccessFromBreak[nullBreak]"];
            };
        RETURN [break.breakAccess];
        };

    BreakTableFromBreakAccess: PROCEDURE [breakAccess: Breakpoint.BreakAccess]
    RETURNS [RefTab.Ref] ~ {
        IF breakAccess = Breakpoint.nullBreakAccess THEN {
            ERROR Breakpoint.Cant[code: $NullBreakAccess, message: "Null breakAccess"];
            };
        IF breakAccess.data = Breakpoint.nullBreakAccessData THEN {
            ERROR Breakpoint.Cant[code: $NullBreakAccessData, message: "Null breakAccess.data"];
            };
        RETURN [breakAccess.data.breakTable];
        };

}.
    <<>>