124 lines
3.8 KiB
Rust
124 lines
3.8 KiB
Rust
// When testing functions, QuickCheck (QC) uses small values for integer (`u*`/`i*`) arguments
|
|
// (~ `[-100, 100]`), but these values don't stress all the code paths in our intrinsics. Here we
|
|
// create newtypes over the primitive integer types with the goal of having full control over the
|
|
// random values that will be used to test our intrinsics.
|
|
|
|
use std::boxed::Box;
|
|
use std::fmt;
|
|
|
|
use quickcheck::{Arbitrary, Gen};
|
|
|
|
use int::LargeInt;
|
|
|
|
// Generates values in the full range of the integer type
|
|
macro_rules! arbitrary {
|
|
($TY:ident : $ty:ident) => {
|
|
#[derive(Clone, Copy)]
|
|
pub struct $TY(pub $ty);
|
|
|
|
impl Arbitrary for $TY {
|
|
fn arbitrary<G>(g: &mut G) -> $TY
|
|
where G: Gen
|
|
{
|
|
$TY(g.gen())
|
|
}
|
|
|
|
fn shrink(&self) -> Box<Iterator<Item=$TY>> {
|
|
struct Shrinker {
|
|
x: $ty,
|
|
}
|
|
|
|
impl Iterator for Shrinker {
|
|
type Item = $TY;
|
|
|
|
fn next(&mut self) -> Option<$TY> {
|
|
self.x /= 2;
|
|
if self.x == 0 {
|
|
None
|
|
} else {
|
|
Some($TY(self.x))
|
|
}
|
|
}
|
|
}
|
|
|
|
if self.0 == 0 {
|
|
::quickcheck::empty_shrinker()
|
|
} else {
|
|
Box::new(Shrinker { x: self.0 })
|
|
}
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for $TY {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
fmt::Debug::fmt(&self.0, f)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
arbitrary!(I32: i32);
|
|
arbitrary!(U32: u32);
|
|
|
|
// These integers are "too large". If we generate e.g. `u64` values in the full range then there's
|
|
// only `1 / 2^32` chance of seeing a value smaller than `2^32` (i.e. whose higher "word" (32-bits)
|
|
// is `0`)! But this is an important group of values to tests because we have special code paths for
|
|
// them. Instead we'll generate e.g. `u64` integers this way: uniformly pick between (a) setting the
|
|
// low word to 0 and generating a random high word, (b) vice versa: high word to 0 and random low
|
|
// word or (c) generate both words randomly. This let's cover better the code paths in our
|
|
// intrinsics.
|
|
macro_rules! arbitrary_large {
|
|
($TY:ident : $ty:ident) => {
|
|
#[derive(Clone, Copy)]
|
|
pub struct $TY(pub $ty);
|
|
|
|
impl Arbitrary for $TY {
|
|
fn arbitrary<G>(g: &mut G) -> $TY
|
|
where G: Gen
|
|
{
|
|
if g.gen() {
|
|
$TY($ty::from_parts(g.gen(), g.gen()))
|
|
} else if g.gen() {
|
|
$TY($ty::from_parts(0, g.gen()))
|
|
} else {
|
|
$TY($ty::from_parts(g.gen(), 0))
|
|
}
|
|
}
|
|
|
|
fn shrink(&self) -> Box<Iterator<Item=$TY>> {
|
|
struct Shrinker {
|
|
x: $ty,
|
|
}
|
|
|
|
impl Iterator for Shrinker {
|
|
type Item = $TY;
|
|
|
|
fn next(&mut self) -> Option<$TY> {
|
|
self.x /= 2;
|
|
if self.x == 0 {
|
|
None
|
|
} else {
|
|
Some($TY(self.x))
|
|
}
|
|
}
|
|
}
|
|
|
|
if self.0 == 0 {
|
|
::quickcheck::empty_shrinker()
|
|
} else {
|
|
Box::new(Shrinker { x: self.0 })
|
|
}
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for $TY {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
fmt::Debug::fmt(&self.0, f)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
arbitrary_large!(I64: i64);
|
|
arbitrary_large!(U64: u64);
|