You can also use the -xport64 option to check for situations in which the normal ISO C value-preserving rules allow for the extension of the sign of a signed-integral value in an expression of unsigned-integral type. Such sign extensions can cause subtle run-time bugs.
example% cat test3.c int i= -1; void promo(unsigned long l) {} int main() { unsigned long l; l = i; // warn promo(i); // warn } example% CC -c -xarch=v9 -Qoption ccfe -xport64=full test3.c "test3.c", line 6: Warning: Sign extension from "int" to 64-bit integer. "test3.c", line 7: Warning: Sign extension from "int" to 64-bit integer. 2 Warning(s) detected. |