Function test_ptr_out_of_bounds

tests/all/component_model/strings.rs:206–260

(engine: &Engine, src: &str, dst: &str)

}

fn test_ptr_out_of_bounds(engine: &Engine, src: &str, dst: &str) -> Result<()> {
    let test = |len: u32| -> Result<()> {
        let component = format!(
            r#"
(component
  (component $c
    (core module $m
      (func (export "") (param i32 i32))
      (func (export "realloc") (param i32 i32 i32 i32) (result i32) i32.const 0)
      (memory (export "memory") 1)
    )
    (core instance $m (instantiate $m))
    (func (export "a") (param "a" string)
      (canon lift (core func $m "") (realloc (func $m "realloc")) (memory $m "memory")
        string-encoding={dst})
    )
  )

  (component $c2
    (import "a" (func $f (param "a" string)))
    (core module $libc
      (memory (export "memory") 1)
    )
    (core instance $libc (instantiate $libc))
    (core func $f (canon lower (func $f) string-encoding={src} (memory $libc "memory")))
    (core module $m
      (import "" "" (func $f (param i32 i32)))

      (func $start (call $f (i32.const 0x8000_0000) (i32.const {len})))
      (start $start)
    )
    (core instance (instantiate $m (with "" (instance (export "" (func $f))))))
  )

  (instance $c (instantiate $c))
  (instance $c2 (instantiate $c2 (with "a" (func $c "a"))))
)
"#
        );
        let component = Component::new(engine, &component)?;
        let mut store = Store::new(engine, ());
        let trap = Linker::new(engine)
            .instantiate(&mut store, &component)
            .err()
            .unwrap()
            .downcast::<Trap>()?;
        assert_eq!(trap, Trap::StringOutOfBounds);
        Ok(())
    };

    test(0)?;
    test(1)?;

    Ok(())
}

// Test that even if the ptr+len calculation overflows then a trap still
// happens.