pub struct BoundsCheckPolicies {
    pub index: BoundsCheckPolicy,
    pub buffer: BoundsCheckPolicy,
    pub image_load: BoundsCheckPolicy,
    pub image_store: BoundsCheckPolicy,
    pub binding_array: BoundsCheckPolicy,
}
Expand description

Policies for injecting bounds checks during code generation.

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§index: BoundsCheckPolicy

How should the generated code handle array, vector, or matrix indices that are out of range?

§buffer: BoundsCheckPolicy

How should the generated code handle array, vector, or matrix indices that are out of range, when those values live in a GlobalVariable in the Storage or Uniform address spaces?

Some graphics hardware provides “robust buffer access”, a feature that ensures that using a pointer cannot access memory outside the ‘buffer’ that it was derived from. In Naga terms, this means that the hardware ensures that pointers computed by applying Access and AccessIndex expressions to a GlobalVariable whose space is Storage or Uniform will never read or write memory outside that global variable.

When hardware offers such a feature, it is probably undesirable to have Naga inject bounds checking code for such accesses, since the hardware can probably provide the same protection more efficiently. However, bounds checks are still needed on accesses to indexable values that do not live in buffers, like local variables.

So, this option provides a separate policy that applies only to accesses to storage and uniform globals. When depending on hardware bounds checking, this policy can be Unchecked to avoid unnecessary overhead.

When special hardware support is not available, this should probably be the same as index_bounds_check_policy.

§image_load: BoundsCheckPolicy

How should the generated code handle image texel loads that are out of range?

This controls the behavior of ImageLoad expressions when a coordinate, texture array index, level of detail, or multisampled sample number is out of range.

§image_store: BoundsCheckPolicy

How should the generated code handle image texel stores that are out of range?

This controls the behavior of ImageStore statements when a coordinate, texture array index, level of detail, or multisampled sample number is out of range.

This policy should’t be needed since all backends should ignore OOB writes.

§binding_array: BoundsCheckPolicy

How should the generated code handle binding array indexes that are out of bounds.

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impl BoundsCheckPolicies

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pub fn choose_policy( &self, base: Handle<Expression>, types: &UniqueArena<Type>, info: &FunctionInfo ) -> BoundsCheckPolicy

Determine which policy applies to base.

base is the “base” expression (the expression being indexed) of a Access and AccessIndex expression. This is either a pointer, a value, being directly indexed, or a binding array.

See the documentation for BoundsCheckPolicy for details about when each policy applies.

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pub fn contains(&self, policy: BoundsCheckPolicy) -> bool

Return true if any of self’s policies are policy.

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impl Clone for BoundsCheckPolicies

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fn clone(&self) -> BoundsCheckPolicies

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for BoundsCheckPolicies

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl Default for BoundsCheckPolicies

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fn default() -> BoundsCheckPolicies

Returns the “default value” for a type. Read more
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impl Hash for BoundsCheckPolicies

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fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl PartialEq for BoundsCheckPolicies

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fn eq(&self, other: &BoundsCheckPolicies) -> bool

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl Copy for BoundsCheckPolicies

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impl Eq for BoundsCheckPolicies

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impl StructuralEq for BoundsCheckPolicies

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impl StructuralPartialEq for BoundsCheckPolicies

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Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.