coverage: Explicitly note that counter/expression IDs are function-local

This commit is contained in:
Zalathar 2023-10-18 12:44:47 +11:00
parent 753caf292c
commit 33da0978ac
2 changed files with 17 additions and 0 deletions

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@ -100,6 +100,13 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> {
#[instrument(level = "debug", skip(self))]
fn add_coverage(&mut self, instance: Instance<'tcx>, coverage: &Coverage) {
// Our caller should have already taken care of inlining subtleties,
// so we can assume that counter/expression IDs in this coverage
// statement are meaningful for the given instance.
//
// (Either the statement was not inlined and directly belongs to this
// instance, or it was inlined *from* this instance.)
let bx = self;
let Some(function_coverage_info) =

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@ -9,6 +9,11 @@ use std::fmt::{self, Debug, Formatter};
rustc_index::newtype_index! {
/// ID of a coverage counter. Values ascend from 0.
///
/// Before MIR inlining, counter IDs are local to their enclosing function.
/// After MIR inlining, coverage statements may have been inlined into
/// another function, so use the statement's source-scope to find which
/// function/instance its IDs are meaningful for.
///
/// Note that LLVM handles counter IDs as `uint32_t`, so there is no need
/// to use a larger representation on the Rust side.
#[derive(HashStable)]
@ -24,6 +29,11 @@ impl CounterId {
rustc_index::newtype_index! {
/// ID of a coverage-counter expression. Values ascend from 0.
///
/// Before MIR inlining, expression IDs are local to their enclosing function.
/// After MIR inlining, coverage statements may have been inlined into
/// another function, so use the statement's source-scope to find which
/// function/instance its IDs are meaningful for.
///
/// Note that LLVM handles expression IDs as `uint32_t`, so there is no need
/// to use a larger representation on the Rust side.
#[derive(HashStable)]