41 lines
954 B
Rust
41 lines
954 B
Rust
|
// Check that CopyProp does not propagate an assignment to a function argument
|
||
|
|
// (doing so can break usages of the original argument value)
|
||
|
|
// unit-test: CopyProp
|
||
|
|
fn dummy(x: u8) -> u8 {
|
||
|
|
x
|
||
|
|
}
|
||
|
|
|
||
|
|
// EMIT_MIR copy_propagation_arg.foo.CopyProp.diff
|
||
|
|
fn foo(mut x: u8) {
|
||
|
|
// calling `dummy` to make a use of `x` that copyprop cannot eliminate
|
||
|
|
x = dummy(x); // this will assign a local to `x`
|
||
|
|
}
|
||
|
|
|
||
|
|
// EMIT_MIR copy_propagation_arg.bar.CopyProp.diff
|
||
|
|
fn bar(mut x: u8) {
|
||
|
|
dummy(x);
|
||
|
|
x = 5;
|
||
|
|
}
|
||
|
|
|
||
|
|
// EMIT_MIR copy_propagation_arg.baz.CopyProp.diff
|
||
|
|
fn baz(mut x: i32) -> i32 {
|
||
|
|
// self-assignment to a function argument should be eliminated
|
||
|
|
x = x;
|
||
|
|
x
|
||
|
|
}
|
||
|
|
|
||
|
|
// EMIT_MIR copy_propagation_arg.arg_src.CopyProp.diff
|
||
|
|
fn arg_src(mut x: i32) -> i32 {
|
||
|
|
let y = x;
|
||
|
|
x = 123; // Don't propagate this assignment to `y`
|
||
|
|
y
|
||
|
|
}
|
||
|
|
|
||
|
|
fn main() {
|
||
|
|
// Make sure the function actually gets instantiated.
|
||
|
|
foo(0);
|
||
|
|
bar(0);
|
||
|
|
baz(0);
|
||
|
|
arg_src(0);
|
||
|
|
}
|