Currently, Clang previously diagnosed this code by default:
void f(int a[static 0]);
saying that "static has no effect on zero-length arrays", which was
accurate.
However, static array extents require that the caller of the function
pass a nonnull pointer to an array of *at least* that number of
elements, but it can pass more (see C17 6.7.6.3p6). Given that we allow
zero-sized arrays as a GNU extension and that it's valid to pass more
elements than specified by the static array extent, we now support
zero-sized static array extents with the usual semantics because it can
be useful in cases like:
void my_bzero(char p[static 0], int n);
my_bzero(&c+1, 0); //ok
my_bzero(t+k,n-k); //ok, pattern from actual code
Fix a bug where we would compare array sizes with incompatible
element types, and look through explicit casts.
rdar://44800168
Differential revision: https://reviews.llvm.org/D57064
llvm-svn: 352239
the no-arguments case. Don't expand this to an __attribute__((nonnull(A, B,
C))) attribute, since that does the wrong thing for function templates and
varargs functions.
In passing, fix a grammar error in the diagnostic, a crash if
__attribute__((nonnull(N))) is applied to a varargs function,
a bug where the same null argument could be diagnosed multiple
times if there were multiple nonnull attributes referring to it,
and a bug where nonnull attributes would not be accumulated correctly
across redeclarations.
llvm-svn: 216520
Aaron Ballman