I totally see the point of this, but still, you have to admit this is pretty funny:
> Developers sometimes experience trouble debugging the quarter-million line amalgamation source file because some debuggers are only able to handle source code line numbers less than 32,768 [...] To circumvent this limitation, the amalgamation is also available in a split form, consisting of files "sqlite3-1.c", "sqlite3-2.c", and so forth, where each file is less than 32,768 lines in length
That would imply that such debuggers are storing line numbers as not just 16-bit numbers (which is probably sensible, considering that source files longer than that are uncommon), but as signed 16-bit numbers. I can't fathom a situation where line numbers would ever be negative.
Notably, unsigned integers also have defined behavior for overflow. This means compilers can do less optimization on unsigned integers. For example, they can't assume that. x + 1 > x for unsigned ints, but are free to assume that for standard ints.
That is just another reason to stick with signed ints unless there is a very specific behavior you rely on.
> For example, they can't assume that. x + 1 > x for unsigned ints, but are free to assume that for standard ints.
No they ain't:
julia> x = typemax(Int16)
32767
julia> x + Int16(1) > x
false
Integers are integers, and can roll over regardless of whether or not they're signed. Avoiding rollover is not a reason to stick with signed integers; indeed, rollover is a very good reason to avoid using signed integers unless you're specifically prepared to handle unexpectedly-negative values.
It depends on the language. I linked a set of c++ guidelines and for c++, they are correct: it is undefined behaviour to do signed integer overflow. Some languages do specify it, eg rust, and even in c++ it might appear to work, but even then it is still undefined and should be strongly avoided.
Yes... And debuggers that implement line numbers, generally work by taking that information as part of the preprocessing stage. And the #line and __LINE__ macro/directive were implemented _for debuggers_ when originally created. They were made to be handed over to the debugger.
If you simply compile and run, the debugger won't have __LINE__, no. But it also won't have line numbers, at all. So you might have missed a bit of context to this discussion - how are line numbers implemented in a debugger that does so, without access to the source?
No, the debugger does not get involved in preprocessing. When you write "a = __LINE__;", it expands to "a = 10;" (or whatever number) and is compiled, and the debugger has no knowledge of it. Debugging information, including the mapping of positions in the code to positions in the source, is generated by the compiler and embedded directly into the generated binary or an external file, from which the debugger reads it.
The __LINE__ macro is passed to the debugger only if the program itself outputs its value, and the "debugger" is a human reading that output :)
> Developers sometimes experience trouble debugging the quarter-million line amalgamation source file because some debuggers are only able to handle source code line numbers less than 32,768 [...] To circumvent this limitation, the amalgamation is also available in a split form, consisting of files "sqlite3-1.c", "sqlite3-2.c", and so forth, where each file is less than 32,768 lines in length