Symantec Top 10

By Craig Conner and Scott Morison

With the release of 8.1, we thought we would run through some update questions for both Pascal and C/C++ PPC projects, and then look at some interesting features. We end with some 68K questions and a C++ language update.

Q: With the introduction of the Pascal drop-in for SPM, what is involved in porting Think Pascal code to the PPC?

A: First, we would like to thank Language Systems for creating the drop-in PPC Pascal compiler for SPM. Now, on to the answer. To port code involves several steps. First, you need to update your code following Apple’s recommended steps to migrate from 68K code to PowerPC code. Consult Chapter 3 of the Object Pascal.pdf file for more specific info. To ease this transition you can use the Universal Headers 2.1 that we released for Think Pascal and do the changes within the Think environment.

Second, when you create the project, you need to include the following libraries, or use the Project Model:

InterfaceLib

MathLib

PascalUPPGlue.o

PasLibx.o

PPCANSI.o

PPCRuntime.o

PPCunix.o

Third, you will need to add the relevant units into a USES statement both in your source code and in the project. (You can also use the {$I} syntax used by MPW to include files.)

Q: Can I use block comments in Language Systems Pascal?

A: Yes! LS Pascal is similar to MPW Pascal in that regard. Use braces, like this:

    {
    This is a
    block comment
    }

Q: I’m trying to update a project from 8.0.3 to 8.1, and I get the error message:

File "InterfaceLib.xcoff"

Error: the file was not found.

I also get the same message for the MathLib.xcoff and ObjectSupportLib.xcoff. Why is this?

A: You will need to replace InterfaceLib.xcoff with InterfaceLib, MathLib.xcoff with MathLib, and ObjectSupportLib.xcoff with ObjectSupportLib. These libraries have changed from xcoff library stubs to actual shared library stubs, so these files have lost the .xcoff extension. Remove the old libraries and add the new versions.

Q: Okay, I now have the right libraries, but I get a continuous stream of errors like this:

Prefix "PowerPC C++"; Line 1; While compiling "CStream_myContents.cpp"

Error: different configuration for precompiled header

A: The default precompiled header has the Exception Handling switch on, but most converted files convert with the switch off. You can find the switch by choosing Options from the Project menu and looking at the PowerPC C++ Language Settings. If that does not help it is time to re-precompile the header. To quickly precompile the header you can simply choose the Precompile Header script from the Scripts menu.

Q: Why do I now notice a pause and then a dialog box opening when entering variables in the data window?

A: SC++ 8.1 allows for deferring debugging file generation. This both speeds up compile times and limits the size of the compiled project. The downside is that when you ask for information from a file that doesn’t have debug information created yet, the debugger needs to take a moment and create it.

Q: I am using the SPM and trying to get my 68K application to link. ToolServer starts to open, and then it posts a dialog saying StdCLib could not be found. Why?

A: ToolServer 3.4 requires the StdCLibInit extension to be loaded in your Extensions folder. You can copy it from the 8.1 disk System Additions folder.

Q: The Apple Guide tutorials don’t show up in my Help menu. Why not?

A: For the SPM to load the Apple Guides, you need to have the AppleGuide extension loaded in your Extensions folder. Look for more Apple Guides in the future.

Q: My TPM project complains about not being able to find the ANSI library; what has changed?

A: The following TPM libraries’ names have been changed in a minor but important way:

ANSI-A4

ANSI-A4++

ANSI-small

ANSI-small++

CPlusLib-A4

These libraries all used to use em-dashes (option-hyphen) in their names instead of hyphens. Due to problems this causes on Japanese systems, the em-dashes have been changed to regular hyphens. Projects which use these libraries will have to remove and re-add them in order for TPM to be able to recognize the libraries with their new names.

Q: How do I use AppendDITL() in a Think Pascal project?

A: This call was new to System 7 and never really made it into the old toolbox library. It is, however, declared in the CommToolBox.lib. Here is the way to get it working.

Add CommToolBox.lib to your project.

Create a unit (or modify an existing one) that declares AppendDITL as external. Something like:

 unit myDeclarations;
 interface

 procedure AppendDITL(
 theDialog:DialogPtr; 
 theHandle:Handle; 
 method:integer);

 implementation

 procedure AppendDITL(
 theDialog:DialogPtr;
 theHandle:Handle;
 method:integer);
 external;

 end.

Notice that I changed the method parameter to an integer type, so that I would not have to declare DITLMethod also. (You may want to declare that, and the method constants also for elegance.)

Q: Do I still have to use the pragmas for instantiation of static templates?

A: No. The compiler now accepts template-explicit instantiation as outlined in the ANSI C++ draft standard (dated 9/26/95) Section 14.4 pp. 14-15. The following pre-8.1.0 statements:

 template <class T> void f(T t);
 template <class T> class X { };

 #pragma template_access public
 #pragma template f(int)
 #pragma template X<int>

are equivalent to:

 template <class T> void f(T t);
 template <class T> class X { };

 template void f(int);
 template class X<int>;

Note: The old method of using #pragma template directives continues to be supported.

Special thanks to: Glenn Austin, Michael Hopkins, Kevin Quah, and Mark Baldwin.