Struct rustc_mir_transform::coverage::graph::BasicCoverageBlockData
source · 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 BasicBlock
s 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 andcatch_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 aGoto
, 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.
Fields§
§basic_blocks: Vec<BasicBlock>
Implementations§
source§impl BasicCoverageBlockData
impl BasicCoverageBlockData
pub fn from(basic_blocks: Vec<BasicBlock>) -> Self
pub fn leader_bb(&self) -> BasicBlock
pub fn last_bb(&self) -> BasicBlock
pub fn terminator<'a, 'tcx>( &self, mir_body: &'a Body<'tcx> ) -> &'a Terminator<'tcx>
Trait Implementations§
source§impl Clone for BasicCoverageBlockData
impl Clone for BasicCoverageBlockData
source§fn clone(&self) -> BasicCoverageBlockData
fn clone(&self) -> BasicCoverageBlockData
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moreAuto Trait Implementations§
impl RefUnwindSafe for BasicCoverageBlockData
impl Send for BasicCoverageBlockData
impl Sync for BasicCoverageBlockData
impl Unpin for BasicCoverageBlockData
impl UnwindSafe for BasicCoverageBlockData
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
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