On 01/04/2017 09:05 PM, Alexandre Oliva wrote:
On Jan 4, 2017, Martin Sebor <mse...@gmail.com> wrote:
The manual recommends to use a length modifier to constrain the length
of output to that of a narrower type:
sprintf (xname, "<U%4hx>", ((unsigned short)((uintptr_t)(t) & 0xffff)));
This should work even without optimization.
It might not work if short happens to be wider than 16 bits, but I guess
we need not worry about that at -O1.
In stage2 of bootstrap-O1, the code that warns if sprintf might
overflow its output buffer cannot tell that an unsigned value narrowed
to 16 bits will fit in 4 bytes with %4x.
Converting the value to 'unsigned short' makes it obvious that it
fits, at least on machines with 16-bit shorts.
Regstrapped on x86_64-linux-gnu and i686-linux-gnu. Ok to install?
for gcc/c-family/ChangeLog
* c-pretty-print.c (pp_c_tree_decl_identifier): Convert 16-bit
value to unsigned short to fit in 4 hex digits without
warnings.
OK.
jeff
