181–190 of 329 posts
Why is there no brief explanations in this code why each function is banned?
I'd assume there are no comments explaining this because for the intended audience, it is self-evident. "People browsing Hacker News on a Sunday" was probably not the intended audience :-).
I'm glad to see that setjmp() and longjmp() are still allowed. I'm just kidding by the way. For those C programmers who haven't encountered these before, it is a powerful way to do a "goto" in C. Powerful in the sense that you can jump anywhere, not limited to the same function. If it's used at all these days, it's used for exception handling. More info: https://en.wikipedia.org/wiki/Setjmp.h
You can build coroutines from them, too, which is really cool and useful.
Why is there no brief explanations in this code why each function is banned?
Here are some of them:
- strcpy()'s rationale: https://github.com/git/git/commit/c8af66ab8ad7cd78557f0f9f5ef6a52fd46ee6dd
- strcat()'s rationale: https://github.com/git/git/commit/1b11b64b815db62f93a04242e4aed5687a448748
- strncat()'s rationale: https://github.com/git/git/commit/ace5707a803eda0f1dde3d776dc3729d3bc7759a
- sprintf()'s rationale: https://github.com/git/git/commit/cc8fdaee1eeaf05d8dd55ff11f111b815f673c58I'm glad to see that setjmp() and longjmp() are still allowed. I'm just kidding by the way. For those C programmers who haven't encountered these before, it is a powerful way to do a "goto" in C. Powerful in the sense that you can jump anywhere, not limited to the same function. If it's used at all these days, it's used for exception handling. More info: https://en.wikipedia.org/wiki/Setjmp.h
I don't use setjmp() and longjmp() often, but sometimes I do; I use goto more often than those (but still not all the time). (I want goto in JavaScript too. I figured out a algorithm to do so, but have not implemented it.) One use of setjmp/longjmp I have used is in ZORKMID, to deal with the debugger. At the beginning of the execute() function I have: while(setjmp(exception_buffer)); (The semicolon is correct; the lo…
Windows programmers are familiar with StrSafe.h, https://en.wikipedia.org/wiki/Strsafe.h and https://github.com/dotnet/coreclr/blob/master/src/pal/inc/st... which go a lot further. Also found https://github.com/mubix/netview/blob/master/banned.h on Github with a better list.
Additionally we get to enjoy bounds checked arrays(std::...), and iterators on debug builds, with possibility to selectively enable them in release mode. While Windows by all means still has its security issues, the toolchain is much more security oriented than most FOSS alternatives thanks to the Windows XP wake up call. Android and ChromeOS are probably the mostly locked down alternatives on the FOSS space.
Earlier quoted context omitted.
Looks more like an implementation of undefined behaviour to me.
The underlying implementations define the behavior here very well.
Earlier quoted context omitted.
I'm not an expert in C, but then what's the issue with strncpy() or any "n" functions? It prevents overflow AFAIK. Also what is the alternative (memcpy?) and why?
strncpy() does not guarantee that the copied string would be terminated with a null byte ('\0'). For a call that looks like strncpy(dst, src, n), if there is no null byte in the first n bytes of src, the string copied to dst would also not contain a null byte. Here is an example code to demonstrate the problem: #include #include int main() { char a[] = "01234567"; strncpy(a, "foobar", 4); printf("%.8s\n", a); return…
Why is there no brief explanations in this code why each function is banned?
Look at the commit comments ( https://github.com/git/git/commits/master/banned.h )
[0]: https://github.com/git/git/commit/c8af66ab8ad7cd78557f0f9f5e...
I'm glad to see that setjmp() and longjmp() are still allowed. I'm just kidding by the way. For those C programmers who haven't encountered these before, it is a powerful way to do a "goto" in C. Powerful in the sense that you can jump anywhere, not limited to the same function. If it's used at all these days, it's used for exception handling. More info: https://en.wikipedia.org/wiki/Setjmp.h
These are used /everywhere/ in PostgreSQL, exactly for exception handling. The result isn't bad at all, but indeed, too powerful a tool for 99% of developers