rust/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs

90 lines
2.9 KiB
Rust

use rustc_middle::mir::coverage::{CounterValueReference, MappedExpressionIndex};
/// Must match the layout of `LLVMRustCounterKind`.
#[derive(Copy, Clone, Debug)]
#[repr(C)]
pub enum CounterKind {
Zero = 0,
CounterValueReference = 1,
Expression = 2,
}
/// A reference to an instance of an abstract "counter" that will yield a value in a coverage
/// report. Note that `id` has different interpretations, depending on the `kind`:
/// * For `CounterKind::Zero`, `id` is assumed to be `0`
/// * For `CounterKind::CounterValueReference`, `id` matches the `counter_id` of the injected
/// instrumentation counter (the `index` argument to the LLVM intrinsic
/// `instrprof.increment()`)
/// * For `CounterKind::Expression`, `id` is the index into the coverage map's array of
/// counter expressions.
///
/// Corresponds to struct `llvm::coverage::Counter`.
///
/// Must match the layout of `LLVMRustCounter`.
#[derive(Copy, Clone, Debug)]
#[repr(C)]
pub struct Counter {
// Important: The layout (order and types of fields) must match its C++ counterpart.
pub kind: CounterKind,
id: u32,
}
impl Counter {
/// Constructs a new `Counter` of kind `Zero`. For this `CounterKind`, the
/// `id` is not used.
pub fn zero() -> Self {
Self { kind: CounterKind::Zero, id: 0 }
}
/// Constructs a new `Counter` of kind `CounterValueReference`, and converts
/// the given 1-based counter_id to the required 0-based equivalent for
/// the `Counter` encoding.
pub fn counter_value_reference(counter_id: CounterValueReference) -> Self {
Self { kind: CounterKind::CounterValueReference, id: counter_id.zero_based_index() }
}
/// Constructs a new `Counter` of kind `Expression`.
pub fn expression(mapped_expression_index: MappedExpressionIndex) -> Self {
Self { kind: CounterKind::Expression, id: mapped_expression_index.into() }
}
/// Returns true if the `Counter` kind is `Zero`.
pub fn is_zero(&self) -> bool {
matches!(self.kind, CounterKind::Zero)
}
/// An explicitly-named function to get the ID value, making it more obvious
/// that the stored value is now 0-based.
pub fn zero_based_id(&self) -> u32 {
debug_assert!(!self.is_zero(), "`id` is undefined for CounterKind::Zero");
self.id
}
}
/// Corresponds to enum `llvm::coverage::CounterExpression::ExprKind`.
///
/// Must match the layout of `LLVMRustCounterExprKind`.
#[derive(Copy, Clone, Debug)]
#[repr(C)]
pub enum ExprKind {
Subtract = 0,
Add = 1,
}
/// Corresponds to struct `llvm::coverage::CounterExpression`.
///
/// Must match the layout of `LLVMRustCounterExpression`.
#[derive(Copy, Clone, Debug)]
#[repr(C)]
pub struct CounterExpression {
pub kind: ExprKind,
pub lhs: Counter,
pub rhs: Counter,
}
impl CounterExpression {
pub fn new(lhs: Counter, kind: ExprKind, rhs: Counter) -> Self {
Self { kind, lhs, rhs }
}
}