COSC422_Project2/proj2.pas at master · rob0229/COSC422_Project2 · GitHub

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{*
Name: proj2.pas
Programmers: Kevin Masterson (k.m.masterson@gmail.com), Rob Close (rob0229@gmail.com)
*}

program project2;
uses crt, sysutils, strutils, types, menu, functions;

procedure initProgram();
    var
        i: integer;
        input: string;
    begin
        {* initial empty function array *}
        num_functions := 0;
        setlength(func_array, num_functions);

        {* beginning of stack *}
        stack_base := 1000000;
        {* no code yet! *}
        instruction_pointer := -1;
        {* stack pointer starts off at first record *}
        stack_pointer := 0;

        {* initial stack array *}
        stack_size := 1;
        setlength(stack, stack_size);
        stack[0].name := 'Global Variables';
        stack[0].control_link := -1;
        stack[0].access_link := -1;
        stack[0].offset := 0;
        stack[0].return_address := -1;

        stack[0].num_locals := -1;
        while stack[0].num_locals = -1 do
            begin
                writeln('Enter the number of global variables');
                readln(input);
                stack[0].num_locals := StrToIntDef(input, -1);
            end;

        setlength(stack[0].locals, stack[0].num_locals);
        for i := 0 to (stack[0].num_locals - 1) do
            begin
                writeln('Enter the variable name for global var ', i+1, ': ');
                readln(stack[0].locals[i].var_name);
                writeln('Enter the data type of ', stack[0].locals[i].var_name, ': ');
                readln(stack[0].locals[i].var_type);
                writeln('Enter a value for ', stack[0].locals[i].var_name, ': ');
                readln(stack[0].locals[i].var_value);
            end;

        stack[0].size := stack[0].num_locals * 4;
    end;

procedure runLoop();
    var
        choice, numprint: integer;
        input: string;

    begin
        display_menu();
        readln(input);

        choice := StrToIntDef(input, -1);

        while choice <> 5 do
            begin
                case choice of
                    {* Create a function *}
                    1 :
                        begin
                            num_functions := num_functions + 1;
                            setlength(func_array, num_functions);
                            func_array[num_functions - 1] := createFunction();
                        end;
                    {*Simulate a function call*}
                    2 :
                        begin
                            {* add the activation record for called function to the stack *}
                            callFunction();
                        end;
                    {* return function *}
                    3:
                        begin
                            functionReturn();
                        end;
                    {* Print the stack *}
                    4 :
                        begin
                            numprint := -1;
                            while numprint = -1 do
                                begin
                                    writeln('Enter number of activation records to print: ');
                                    readln(input);
                                    numprint := StrToIntDef(input, -1);
                                end;
                            printStack(numprint);
                        end;
                    else
                        writeln('That is not a valid choice');
                end;
                display_menu();
                readln(choice);
            end;
         halt; {* exit program entirely if choice was 6 *}
    end;

{* Main program execution*}
begin
    while 1=1 do
        begin
            initProgram();
            runLoop();
        end;
end.