On Fri, 1 Nov 2024 at 15:16, Martin Frb via fpc-pascal <fpc-pascal@lists.freepascal.org> wrote: > On 01/11/2024 15:59, Henry Vermaak via fpc-pascal wrote: > I may not have all the factors, but O- O1 and O2 are not debug info, but > optimization. > So they generate different code, and that leads to different exe sizes.
I understand that. I was comparing a build with (-O2) to a build with (-O2 -g -Xg). The -Xg isn't particularly relevant here, building with (-O2 -g) then stripping leaves you with a binary that's much larger than without -g. This works fine with gcc and the binaries are the same size after stripping. > I am not sure it explains the full size diff you get. Depending on the code, > you may have a difference due to smart linking. > > To check if any other symbols (e.g. those needed for the linker) differ > between the various builds, you can try to use strip, and that shows you how > much actually remains for the app-code/data. All binaries are fully stripped. > Then of course there are a few problems that make the whole thing more > complex. > > gcc can (afaik) generate working debug info for optimized code. > > fpc does not. If data is in registers then fpc does not represent that (at > least not always correctly) in the debug info. So data will be show incorrect > in the debugger. > fpc does not generate line info for inlined code. And I don't know how > well/exact line info is for different level of optimization in different fpc > versions. > And some versions of fpc (or maybe some linkers?) caused broken debug info > when smart linking was enabled. > > So basically, if you want to debug, then you can't really optimize. > Or at least you must check exactly what is supported by the version of fpc > you use. Sure, I understand that optimising messes up debugging, I just want a stack trace that points me in the general direction of what's going wrong (and that works OK in simple tests). Except if fpc ignores -O2 somehow when I pair it with -g? Henry _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
