https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77754
--- Comment #4 from Christophe Monat <christophe.monat at st dot com> --- (In reply to Richard Biener from comment #3) > I wonder what the standards say about side-effects in those "declarations". From my instance of ISO+IEC+9899-2011.pdf 6.7.6.2 Array declarators Constraints ... Semantics (5) If the size is an expression that is not an integer constant expression: if it occurs in a declaration at function prototype scope, it is treated as if it were replaced by *; otherwise, each time it is evaluated it shall have a value greater than zero. The size of each instance of a variable length array type does not change during its lifetime. Where a size expression is part of the operand of a sizeof operator and changing the value of the size expression would not affect the result of the operator, it is unspecified whether or not the size expression is evaluated. And 6.7.6.3 Function declarators (including prototypes) (12) If the function declarator is not part of a definition of that function, parameters may have incomplete type and may use the [*] notation in their sequences of declarator specifiers to specify variable length array types. So to me it looks, like the compiler could consider the original declaration as if it where: void fn2(int[][*]);
