gcc manual page （二）
foo (a)
{
if (a 0)
return a;
}
Spurious warnings can occur because GNU CC does not realize that certain functions (including abort and longjmp) will never return.
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An eXPression-statement or the left-hand side of a comma expression contains no side effects. To suppress the warning, cast the unused expression to void. For example, an expression sUCh as `x[i,j]' will cause a warning, but `x[(void)i,j]' will not.
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An unsigned value is compared against zero wit...[ 查看全文 ]
