array bounds, sanitizer, safe programming, and cilk array notation

[Joseph Myers]

On Mon, 26 Jan 2015, Martin Uecker wrote:

> extern void bar2(int (*x)[5]);

> 	int c = 4;
> 	int y[c];

> 	bar2(&y);	// not diagnosed (found by asan)

This is the undefined behavior "If the two array types are used in a 
context which requires them to be compatible, it is undefined behavior if 
the two size specifiers evaluate to unequal values." (C11 6.7.6.2#6).  
Yes, it would make sense for ubsan to detect this.  Generally, most forms 
of runtime undefined behavior listed in J.2 should have ubsan detection 
unless hard to detect / detected by some other sanitizer such as asan.

Does adding new forms of sanitization require upstream libsanitizer 
changes as well or can arbitrary ubsan checks be added without needing 
libsanitizer changes?

-- 
Joseph S. Myers
joseph@codesourcery.com