Topspeed_JPI/TS/DOC/DOS_ENV.DOC

TopSpeed DOS Environment            Release Notes version 3.10
========================            ==========================


This document contains information on the following:

    1.  KNOWN PROBLEMS IN TOPSPEED RELEASE 3.10
    2.  DIFFERENCES FROM TOPSPEED VERSION 2.00
    3.  DIFFERENCES FROM TOPSPEED VERSION 3.00
    4.  ERRATA AND ADDENDA

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1.  KNOWN PROBLEMS IN TOPSPEED RELEASE 3.10
===========================================

þ   Run time errors in dynalink model will not have line number
    information in the report.

þ   A program containing floating point, compiled with the
    emulator option and being debugged on a machine with a
    co-processor may exhibit erratic behaviour.


2.  DIFFERENCES FROM TOPSPEED VERSION 2.00
==========================================

The TopSpeed Environment for Release 3.10 is different in
appearance, but essentially the same in operation, to that
supplied with Release 2 of TopSpeed Modula-2 and TopSpeed C,
with the following exceptions.

þ   A number of new facilities have been introduced, such as the
    Locate File utility, and a command history in every data-
    entry field using the Tab key.

þ   The project system has been introduced in place of the
    previous make system. This is discussed further below.

þ   The TopSpeed system now supports four TopSpeed languages
    (Pascal, Modula-2, C and C++) rather than two.

þ   The TopSpeed system now supports more memory models,
    including an automatic code and data overlaying model.


3.  DIFFERENCES FROM TOPSPEED VERSION 3.00
==========================================

þ   SmartMethod Linking. Starting with release 3.01 the
    TopSpeed linker is able to smart-link out virtual
    procedures that cannot be called during the execution of
    a program. An option to control SmartMethod linking is on
    the Project Options menu. Note that SmartMethod linking
    will not work if SmartLinking is specified as off.
    The consistency of these options is not yet checked.

þ   Commoning up of identical constants. The TopSpeed linker is
    now capable of assigning identical constants and procedure
    bodies to the same location in memory. This can result in
    size savings on large projects but can also alter the
    semantics of pointer comparisons on constant objects. See the
    help text for further information. This option defaults to
    off.

4. ERRATA AND ADDENDA
======================

The Developer's Guide p 19:

    The second example for the #implib command should read as
    follows:

        #implib <libfile> <expfile>

The Developer's Guide p 32  lines 33 and 34:

    These lines should read as follows:

        #set opath = c:\ts\include\io.def
        #set cpath = d:\test\io.def

The Developer's Guide p56:

    The description of the following call pragma is missing
    from the manual:

        alloca=>on

            This pragma is only used for internal library
            routines. The purpose of this pragma is to modify
            the stack frame of the calling function. When using
            the alloca function you must include the header
            file alloc.h. This pragma cannot be used in a
            project file.

The Developer's Guide p72:

    The name pragma prefix => string cannot be used in project
    files.

The Developer's Guide p91:

    The following link_option pragmas are missing from the
    manual:

        pragma link_option(smart_method => on | off)

            This pragma controls whether the linker will
            eliminate unused virtual methods from the
            executable file. This process, known as Smart
            Method linking, typically results in a significant
            reduction in the executable file size.

            Smart Method linking can only operate when the
            optimize(smart_link) pragma is also specified.

            This option defaults to on, except when a
            dynamic link library is being produced. The
            Project Project options SmartMethod linking
            menu command may be used to specify this option.

        pragma link_option(share_const => on | off)

            This pragma controls whether the linker allocates
            the same memory for identical constant values, or
            whether constants are allocated distinct addresses
            even when they are identical. Sharing identical
            constants reduces the size of executable files,
            but may cause semantic changes in the operation
            of a program if it compares the values of pointers
            to these constants, for example. Identical virtual
            method tables are always shared, regardless of the
            setting of this pragma.

            This pragma defaults to off. The Project Project
            options (H) Share identical constants menu command
            may be used to specify this option.