Files
rust/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs

85 lines
3.3 KiB
Rust

use rustc_data_structures::captures::Captures;
use rustc_middle::mir::coverage::{
CovTerm, CoverageIdsInfo, Expression, FunctionCoverageInfo, Mapping, MappingKind, Op,
SourceRegion,
};
use crate::coverageinfo::ffi::{Counter, CounterExpression, ExprKind};
pub(crate) struct FunctionCoverage<'tcx> {
pub(crate) function_coverage_info: &'tcx FunctionCoverageInfo,
/// If `None`, the corresponding function is unused.
ids_info: Option<&'tcx CoverageIdsInfo>,
}
impl<'tcx> FunctionCoverage<'tcx> {
pub(crate) fn new_used(
function_coverage_info: &'tcx FunctionCoverageInfo,
ids_info: &'tcx CoverageIdsInfo,
) -> Self {
Self { function_coverage_info, ids_info: Some(ids_info) }
}
pub(crate) fn new_unused(function_coverage_info: &'tcx FunctionCoverageInfo) -> Self {
Self { function_coverage_info, ids_info: None }
}
/// Returns true for a used (called) function, and false for an unused function.
pub(crate) fn is_used(&self) -> bool {
self.ids_info.is_some()
}
/// Return the source hash, generated from the HIR node structure, and used to indicate whether
/// or not the source code structure changed between different compilations.
pub(crate) fn source_hash(&self) -> u64 {
if self.is_used() { self.function_coverage_info.function_source_hash } else { 0 }
}
/// Convert this function's coverage expression data into a form that can be
/// passed through FFI to LLVM.
pub(crate) fn counter_expressions(
&self,
) -> impl Iterator<Item = CounterExpression> + ExactSizeIterator + Captures<'_> {
// We know that LLVM will optimize out any unused expressions before
// producing the final coverage map, so there's no need to do the same
// thing on the Rust side unless we're confident we can do much better.
// (See `CounterExpressionsMinimizer` in `CoverageMappingWriter.cpp`.)
self.function_coverage_info.expressions.iter().map(move |&Expression { lhs, op, rhs }| {
CounterExpression {
lhs: self.counter_for_term(lhs),
kind: match op {
Op::Add => ExprKind::Add,
Op::Subtract => ExprKind::Subtract,
},
rhs: self.counter_for_term(rhs),
}
})
}
/// Converts this function's coverage mappings into an intermediate form
/// that will be used by `mapgen` when preparing for FFI.
pub(crate) fn counter_regions(
&self,
) -> impl Iterator<Item = (MappingKind, &SourceRegion)> + ExactSizeIterator {
self.function_coverage_info.mappings.iter().map(move |mapping| {
let Mapping { kind, source_region } = mapping;
let kind =
kind.map_terms(|term| if self.is_zero_term(term) { CovTerm::Zero } else { term });
(kind, source_region)
})
}
fn counter_for_term(&self, term: CovTerm) -> Counter {
if self.is_zero_term(term) { Counter::ZERO } else { Counter::from_term(term) }
}
fn is_zero_term(&self, term: CovTerm) -> bool {
match self.ids_info {
Some(ids_info) => ids_info.is_zero_term(term),
// This function is unused, so all coverage counters/expressions are zero.
None => true,
}
}
}