Astrobe Forum

Another version of the stack trace procedure. The above one stops at the address of the last FP-entry on the stack, this one stops with the contents of this FP-entry. I ran into the problem of where to stop the stack trace when I implemented simple coroutines (as basis for a cooperative task schedul...

Thanks for your explanation. Looks (sounds) like much added complexity without sufficient benefits indeed.

In Oberon, as in many (most?) languages, variables are not initialised by the compiler. Eiffel would be a counter example. I am not sure if general automatic initialisation is a Good Thing, as I prefer if the program text is as explicit as possible. However, there's one exception: pointer variables....

FWIW, here's an improved version of the stack trace procedure. PROCEDURE stackTrace(fpAddr: INTEGER; VAR trace: Trace); VAR lr, stopAt: INTEGER; BEGIN trace.count := 0; stopAt := LinkOptions.StackStart - 8; SYSTEM.GET(fpAddr, fpAddr); WHILE (fpAddr < stopAt) & (trace.count # TraceDepth) DO SYSTEM.GE...

Good hint, thanks. For the module with the run-time error (I only consider run-time error exceptions here, not hardware fault exceptions), the compiler/linker embeds the source line number right in the code at the return address, so that case is covered. The modules in the stack trace need another a...

I see. Thanks for the clarification. May I place a feature request here? If yes, I'd like an extended ResData (".ref") that not only gives the name for a module's address range, but also the procedure names (with address range) within the module.

I am dabbling with getting a stack trace upon run-time errors. For this, I obviously need to understand the structure of the stack when entering the error handler (SVC call). A related questions about interrupt handlers in general. PROCEDURE runtimeErrorHandler[0]; BEGIN . 632 E92D0000H push { } . 6...

Thanks, I have changed my code to use pointers now. As you say, it's clearer and cleaner.

Just out of interest, in the case without having the parameter for P1 declared as VAR, shouldn't the compiler flag the call to P2 from P1, as a read-only variable (p.t) is passed to a VAR parameter in P2?

Thanks. Yes, agreed. Maybe a default config module can make sense for library modules that work without required configuration, but could be tweaked for specific cases, eg. the buffer sizes for a serial driver. But if config is required, there shouldn't be a default config module.

I have several library modules that are basically application-independent, apart from the number of buffers and the buffer sizes. Arrays are easy and well performing data structures for buffers, but they are of a fixed size. For maintenance reasons, I would prefer to configure these library modules ...