pub(super) struct BasicCoverageBlockData {
    pub basic_blocks: Vec<BasicBlock>,
}
Expand description

BasicCoverageBlockData holds the data indexed by a BasicCoverageBlock.

A BasicCoverageBlock (BCB) represents the maximal-length sequence of MIR BasicBlocks without conditional branches, and form a new, simplified, coverage-specific Control Flow Graph, without altering the original MIR CFG.

Note that running the MIR SimplifyCfg transform is not sufficient (and therefore not necessary). The BCB-based CFG is a more aggressive simplification. For example:

  • The BCB CFG ignores (trims) branches not relevant to coverage, such as unwind-related code, that is injected by the Rust compiler but has no physical source code to count. This also means a BasicBlock with a Call terminator can be merged into its primary successor target block, in the same BCB. (But, note: Issue #78544: “MIR InstrumentCoverage: Improve coverage of #[should_panic] tests and catch_unwind() handlers”)
  • Some BasicBlock terminators support Rust-specific concerns–like borrow-checking–that are not relevant to coverage analysis. FalseUnwind, for example, can be treated the same as a Goto, and merged with its successor into the same BCB.

Each BCB with at least one computed coverage span will have no more than one Counter. In some cases, a BCB’s execution count can be computed by Expression. Additional disjoint coverage spans in a BCB can also be counted by Expression (by adding ZERO to the BCB’s primary counter or expression).

The BCB CFG is critical to simplifying the coverage analysis by ensuring graph path-based queries (dominates(), predecessors, successors, etc.) have branch (control flow) significance.

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§basic_blocks: Vec<BasicBlock>

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impl BasicCoverageBlockData

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pub fn from(basic_blocks: Vec<BasicBlock>) -> Self

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pub fn leader_bb(&self) -> BasicBlock

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pub fn last_bb(&self) -> BasicBlock

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pub fn terminator<'a, 'tcx>( &self, mir_body: &'a Body<'tcx> ) -> &'a Terminator<'tcx>

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impl Clone for BasicCoverageBlockData

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fn clone(&self) -> BasicCoverageBlockData

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 BasicCoverageBlockData

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

Formats the value using the given formatter. Read more

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for Twhere 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 Twhere 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 Twhere 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<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 Twhere 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 Twhere 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 Twhere 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 Twhere 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.

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 24 bytes