Questions about vasm and ‘-linedebug’

[Haplo]

Hi all,

I have a few questions about the ‘-linedebug’ command line option of vasm.

(compiling with "vasmm68k_mot.exe -m68000 -kick1hunks -Fhunkexe")

1. The documentation says "Automatically generate an SAS/C-compatible LINE DEBUG hunk for the input source. Overrides any line debugging directives from the source text". However, I have not been able to find any documentation on these "line debugging directives" that can be placed in the source file instead. For example, is it possible to enable line debugging for a certain source file only?

2. My test application is about 140KB. When I add 30k of level data, it becomes 410KB which is a 270K increase. I have confirmed that this blow-out is due to "-line-debug", without it the size increases by only 30K as expected. The level data is about 1200 lines of "dc.b", each line containing 24 bytes of data. Is it expected that line debugging information is getting generated for each of these "dc.b" lines?

3. In general, if an application is 300k but line debugging information blows out its size to 600k, will loading it in a vanilla A500 cause any problems? I assume the loader will throw all this debugging information away and not allocate any memory for it...

Thanks!

[phx]

Originally Posted by Haplo

1. The documentation says "Automatically generate an SAS/C-compatible LINE DEBUG hunk for the input source. Overrides any line debugging directives from the source text". However, I have not been able to find any documentation on these "line debugging directives" that can be placed in the source file instead.

Indeed, they are not documented, because they are only useful for assembler output generated by a High Level Language (usually C) compiler. There is

dsource

to define the absolute path to the HLL source text file. And

debug

to define the original HLL source text line the following code belongs to. These directives are the same as in the PhxAss assembler, which was used with vbcc before vasm.

For example, is it possible to enable line debugging for a certain source file only?

Sure. Either assemble that certain source file with or without

-linedebug

.

But if you refering to source texts included into the main source, or the possibility to disable generation of line-debug information for certain parts of the source, then the answer is currently no.

The line-debug information enabled by

-linedebug

is generated by the hunk-format output module, which can no longer determine what has been code or data. Although it doesn't generate them for

BSS

sections.

Maybe another directive, to control that line-debug generation for certain parts of the source could be added, when really needed.

Originally Posted by Haplo

2. My test application is about 140KB. When I add 30k of level data, it becomes 410KB which is a 270K increase. I have confirmed that this blow-out is due to "-line-debug", without it the size increases by only 30K as expected. The level data is about 1200 lines of "dc.b", each line containing 24 bytes of data. Is it expected that line debugging information is getting generated for each of these "dc.b" lines?

Yes. See above.

Originally Posted by Haplo

3. In general, if an application is 300k but line debugging information blows out its size to 600k, will loading it in a vanilla A500 cause any problems? I assume the loader will throw all this debugging information away and not allocate any memory for it...

Exactly.

LoadSeg()

just skips anything in a

HUNK_DEBUG

hunk. A debugger would need to process the executable's hunk structure again.

[Haplo]

Thanks for the detailed answer! Makes sense.