FunctionCoverage: improve type checking with newtype_index types

This commit is contained in:
Rich Kadel 2020-07-28 17:45:58 -07:00
parent 20f55c193d
commit b58afc088f
2 changed files with 88 additions and 40 deletions

View file

@ -1,3 +1,4 @@
use rustc_index::vec::IndexVec;
use rustc_middle::ty::Instance;
use rustc_middle::ty::TyCtxt;
use rustc_span::source_map::{Pos, SourceMap};
@ -7,6 +8,34 @@ use std::cmp::{Ord, Ordering};
use std::fmt;
use std::path::PathBuf;
rustc_index::newtype_index! {
pub struct ExpressionOperandId {
DEBUG_FORMAT = "ExpressionOperandId({})",
MAX = 0xFFFF_FFFF,
}
}
rustc_index::newtype_index! {
pub struct CounterValueReference {
DEBUG_FORMAT = "CounterValueReference({})",
MAX = 0xFFFF_FFFF,
}
}
rustc_index::newtype_index! {
pub struct InjectedExpressionIndex {
DEBUG_FORMAT = "InjectedExpressionIndex({})",
MAX = 0xFFFF_FFFF,
}
}
rustc_index::newtype_index! {
pub struct MappedExpressionIndex {
DEBUG_FORMAT = "MappedExpressionIndex({})",
MAX = 0xFFFF_FFFF,
}
}
/// Aligns with [llvm::coverage::Counter::CounterKind](https://github.com/rust-lang/llvm-project/blob/rustc/10.0-2020-05-05/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L91)
#[derive(Copy, Clone, Debug)]
#[repr(C)]
@ -38,12 +67,12 @@ impl Counter {
Self { kind: CounterKind::Zero, id: 0 }
}
pub fn counter_value_reference(counter_id: u32) -> Self {
Self { kind: CounterKind::CounterValueReference, id: counter_id }
pub fn counter_value_reference(counter_id: CounterValueReference) -> Self {
Self { kind: CounterKind::CounterValueReference, id: counter_id.into() }
}
pub fn expression(final_expression_index: u32) -> Self {
Self { kind: CounterKind::Expression, id: final_expression_index }
pub fn expression(mapped_expression_index: MappedExpressionIndex) -> Self {
Self { kind: CounterKind::Expression, id: mapped_expression_index.into() }
}
}
@ -143,9 +172,9 @@ impl Region {
#[derive(Clone, Debug)]
pub struct ExpressionRegion {
lhs: u32,
lhs: ExpressionOperandId,
op: ExprKind,
rhs: u32,
rhs: ExpressionOperandId,
region: Region,
}
@ -203,8 +232,8 @@ pub struct ExpressionRegion {
pub struct FunctionCoverage<'a> {
source_map: &'a SourceMap,
source_hash: u64,
counters: Vec<Option<Region>>,
expressions: Vec<Option<ExpressionRegion>>,
counters: IndexVec<CounterValueReference, Option<Region>>,
expressions: IndexVec<InjectedExpressionIndex, Option<ExpressionRegion>>,
unreachable_regions: Vec<Region>,
}
@ -214,8 +243,8 @@ impl<'a> FunctionCoverage<'a> {
Self {
source_map: tcx.sess.source_map(),
source_hash: 0, // will be set with the first `add_counter()`
counters: vec![None; coverageinfo.num_counters as usize],
expressions: vec![None; coverageinfo.num_expressions as usize],
counters: IndexVec::from_elem_n(None, coverageinfo.num_counters as usize),
expressions: IndexVec::from_elem_n(None, coverageinfo.num_expressions as usize),
unreachable_regions: Vec::new(),
}
}
@ -235,7 +264,7 @@ impl<'a> FunctionCoverage<'a> {
} else {
debug_assert_eq!(source_hash, self.source_hash);
}
self.counters[id as usize]
self.counters[CounterValueReference::from(id)]
.replace(Region::new(self.source_map, start_byte_pos, end_byte_pos))
.expect_none("add_counter called with duplicate `id`");
}
@ -263,7 +292,11 @@ impl<'a> FunctionCoverage<'a> {
start_byte_pos: u32,
end_byte_pos: u32,
) {
let expression_index = self.expression_index(id_descending_from_max);
let expression_id = ExpressionOperandId::from(id_descending_from_max);
let lhs = ExpressionOperandId::from(lhs);
let rhs = ExpressionOperandId::from(rhs);
let expression_index = self.expression_index(expression_id);
self.expressions[expression_index]
.replace(ExpressionRegion {
lhs,
@ -294,19 +327,21 @@ impl<'a> FunctionCoverage<'a> {
assert!(self.source_hash != 0);
let counter_regions = self.counter_regions();
let (expressions, expression_regions) = self.expressions_with_regions();
let (counter_expressions, expression_regions) = self.expressions_with_regions();
let unreachable_regions = self.unreachable_regions();
let counter_regions =
counter_regions.chain(expression_regions.into_iter().chain(unreachable_regions));
(expressions, counter_regions)
(counter_expressions, counter_regions)
}
fn counter_regions(&'a self) -> impl Iterator<Item = (Counter, &'a Region)> {
self.counters.iter().enumerate().filter_map(|(index, entry)| {
self.counters.iter_enumerated().filter_map(|(index, entry)| {
// Option::map() will return None to filter out missing counters. This may happen
// if, for example, a MIR-instrumented counter is removed during an optimization.
entry.as_ref().map(|region| (Counter::counter_value_reference(index as u32), region))
entry.as_ref().map(|region| {
(Counter::counter_value_reference(index as CounterValueReference), region)
})
})
}
@ -315,32 +350,39 @@ impl<'a> FunctionCoverage<'a> {
) -> (Vec<CounterExpression>, impl Iterator<Item = (Counter, &'a Region)>) {
let mut counter_expressions = Vec::with_capacity(self.expressions.len());
let mut expression_regions = Vec::with_capacity(self.expressions.len());
let mut new_indexes = vec![u32::MAX; self.expressions.len()];
let mut new_indexes =
IndexVec::from_elem_n(MappedExpressionIndex::from(u32::MAX), self.expressions.len());
// Note, the initial value shouldn't matter since every index in use in `self.expressions`
// will be set, and after that, `new_indexes` will only be accessed using those same
// indexes.
// Note that an `ExpressionRegion`s at any given index can include other expressions as
// operands, but expression operands can only come from the subset of expressions having
// `expression_index`s lower than the referencing `ExpressionRegion`. Therefore, it is
// reasonable to look up the new index of an expression operand while the `new_indexes`
// vector is only complete up to the current `ExpressionIndex`.
let id_to_counter = |new_indexes: &Vec<u32>, id| {
if id < self.counters.len() as u32 {
self.counters
.get(id as usize)
.expect("id is out of range")
.as_ref()
.map(|_| Counter::counter_value_reference(id))
} else {
let index = self.expression_index(id);
self.expressions
.get(index)
.expect("id is out of range")
.as_ref()
.map(|_| Counter::expression(new_indexes[index]))
}
};
let id_to_counter =
|new_indexes: &IndexVec<InjectedExpressionIndex, MappedExpressionIndex>,
id: ExpressionOperandId| {
if id.index() < self.counters.len() {
let index = CounterValueReference::from(id.index());
self.counters
.get(index)
.unwrap() // pre-validated
.as_ref()
.map(|_| Counter::counter_value_reference(index))
} else {
let index = self.expression_index(id);
self.expressions
.get(index)
.expect("expression id is out of range")
.as_ref()
.map(|_| Counter::expression(new_indexes[index]))
}
};
for (original_index, expression_region) in
self.expressions.iter().enumerate().filter_map(|(original_index, entry)| {
self.expressions.iter_enumerated().filter_map(|(original_index, entry)| {
// Option::map() will return None to filter out missing expressions. This may happen
// if, for example, a MIR-instrumented expression is removed during an optimization.
entry.as_ref().map(|region| (original_index, region))
@ -356,10 +398,11 @@ impl<'a> FunctionCoverage<'a> {
{
// Both operands exist. `Expression` operands exist in `self.expressions` and have
// been assigned a `new_index`.
let final_expression_index = counter_expressions.len() as u32;
let mapped_expression_index =
MappedExpressionIndex::from(counter_expressions.len());
counter_expressions.push(CounterExpression::new(lhs_counter, op, rhs_counter));
new_indexes[original_index] = final_expression_index;
expression_regions.push((Counter::expression(final_expression_index), region));
new_indexes[original_index] = mapped_expression_index;
expression_regions.push((Counter::expression(mapped_expression_index), region));
}
}
(counter_expressions, expression_regions.into_iter())
@ -369,8 +412,11 @@ impl<'a> FunctionCoverage<'a> {
self.unreachable_regions.iter().map(|region| (Counter::zero(), region))
}
fn expression_index(&self, id_descending_from_max: u32) -> usize {
debug_assert!(id_descending_from_max as usize >= self.counters.len());
(u32::MAX - id_descending_from_max) as usize
fn expression_index(
&self,
id_descending_from_max: ExpressionOperandId,
) -> InjectedExpressionIndex {
debug_assert!(id_descending_from_max.index() >= self.counters.len());
InjectedExpressionIndex::from(u32::MAX - u32::from(id_descending_from_max))
}
}

View file

@ -8,6 +8,8 @@
#![feature(or_patterns)]
#![feature(trusted_len)]
#![feature(associated_type_bounds)]
#![feature(const_fn)] // for rustc_index::newtype_index
#![feature(const_panic)] // for rustc_index::newtype_index
#![recursion_limit = "256"]
//! This crate contains codegen code that is used by all codegen backends (LLVM and others).