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Diffstat (limited to 'compiler/rustc_middle/src/mir/coverage.rs')
| -rw-r--r-- | compiler/rustc_middle/src/mir/coverage.rs | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/mir/coverage.rs b/compiler/rustc_middle/src/mir/coverage.rs new file mode 100644 index 000000000..efa946452 --- /dev/null +++ b/compiler/rustc_middle/src/mir/coverage.rs @@ -0,0 +1,186 @@ +//! Metadata from source code coverage analysis and instrumentation. + +use rustc_macros::HashStable; +use rustc_span::Symbol; + +use std::cmp::Ord; +use std::fmt::{self, Debug, Formatter}; + +rustc_index::newtype_index! { + /// An ExpressionOperandId value is assigned directly from either a + /// CounterValueReference.as_u32() (which ascend from 1) or an ExpressionOperandId.as_u32() + /// (which _*descend*_ from u32::MAX). Id value `0` (zero) represents a virtual counter with a + /// constant value of `0`. + pub struct ExpressionOperandId { + derive [HashStable] + DEBUG_FORMAT = "ExpressionOperandId({})", + MAX = 0xFFFF_FFFF, + } +} + +impl ExpressionOperandId { + /// An expression operand for a "zero counter", as described in the following references: + /// + /// * <https://github.com/rust-lang/llvm-project/blob/rustc/13.0-2021-09-30/llvm/docs/CoverageMappingFormat.rst#counter> + /// * <https://github.com/rust-lang/llvm-project/blob/rustc/13.0-2021-09-30/llvm/docs/CoverageMappingFormat.rst#tag> + /// * <https://github.com/rust-lang/llvm-project/blob/rustc/13.0-2021-09-30/llvm/docs/CoverageMappingFormat.rst#counter-expressions> + /// + /// This operand can be used to count two or more separate code regions with a single counter, + /// if they run sequentially with no branches, by injecting the `Counter` in a `BasicBlock` for + /// one of the code regions, and inserting `CounterExpression`s ("add ZERO to the counter") in + /// the coverage map for the other code regions. + pub const ZERO: Self = Self::from_u32(0); +} + +rustc_index::newtype_index! { + pub struct CounterValueReference { + derive [HashStable] + DEBUG_FORMAT = "CounterValueReference({})", + MAX = 0xFFFF_FFFF, + } +} + +impl CounterValueReference { + /// Counters start at 1 to reserve 0 for ExpressionOperandId::ZERO. + pub const START: Self = Self::from_u32(1); + + /// Returns explicitly-requested zero-based version of the counter id, used + /// during codegen. LLVM expects zero-based indexes. + pub fn zero_based_index(self) -> u32 { + let one_based_index = self.as_u32(); + debug_assert!(one_based_index > 0); + one_based_index - 1 + } +} + +rustc_index::newtype_index! { + /// InjectedExpressionId.as_u32() converts to ExpressionOperandId.as_u32() + /// + /// Values descend from u32::MAX. + pub struct InjectedExpressionId { + derive [HashStable] + DEBUG_FORMAT = "InjectedExpressionId({})", + MAX = 0xFFFF_FFFF, + } +} + +rustc_index::newtype_index! { + /// InjectedExpressionIndex.as_u32() translates to u32::MAX - ExpressionOperandId.as_u32() + /// + /// Values ascend from 0. + pub struct InjectedExpressionIndex { + derive [HashStable] + DEBUG_FORMAT = "InjectedExpressionIndex({})", + MAX = 0xFFFF_FFFF, + } +} + +rustc_index::newtype_index! { + /// MappedExpressionIndex values ascend from zero, and are recalculated indexes based on their + /// array position in the LLVM coverage map "Expressions" array, which is assembled during the + /// "mapgen" process. They cannot be computed algorithmically, from the other `newtype_index`s. + pub struct MappedExpressionIndex { + derive [HashStable] + DEBUG_FORMAT = "MappedExpressionIndex({})", + MAX = 0xFFFF_FFFF, + } +} + +impl From<CounterValueReference> for ExpressionOperandId { + #[inline] + fn from(v: CounterValueReference) -> ExpressionOperandId { + ExpressionOperandId::from(v.as_u32()) + } +} + +impl From<InjectedExpressionId> for ExpressionOperandId { + #[inline] + fn from(v: InjectedExpressionId) -> ExpressionOperandId { + ExpressionOperandId::from(v.as_u32()) + } +} + +#[derive(Clone, PartialEq, TyEncodable, TyDecodable, Hash, HashStable, TypeFoldable, TypeVisitable)] +pub enum CoverageKind { + Counter { + function_source_hash: u64, + id: CounterValueReference, + }, + Expression { + id: InjectedExpressionId, + lhs: ExpressionOperandId, + op: Op, + rhs: ExpressionOperandId, + }, + Unreachable, +} + +impl CoverageKind { + pub fn as_operand_id(&self) -> ExpressionOperandId { + use CoverageKind::*; + match *self { + Counter { id, .. } => ExpressionOperandId::from(id), + Expression { id, .. } => ExpressionOperandId::from(id), + Unreachable => bug!("Unreachable coverage cannot be part of an expression"), + } + } + + pub fn is_expression(&self) -> bool { + matches!(self, Self::Expression { .. }) + } +} + +impl Debug for CoverageKind { + fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result { + use CoverageKind::*; + match self { + Counter { id, .. } => write!(fmt, "Counter({:?})", id.index()), + Expression { id, lhs, op, rhs } => write!( + fmt, + "Expression({:?}) = {} {} {}", + id.index(), + lhs.index(), + if *op == Op::Add { "+" } else { "-" }, + rhs.index(), + ), + Unreachable => write!(fmt, "Unreachable"), + } + } +} + +#[derive(Clone, TyEncodable, TyDecodable, Hash, HashStable, PartialEq, Eq, PartialOrd, Ord)] +#[derive(TypeFoldable, TypeVisitable)] +pub struct CodeRegion { + pub file_name: Symbol, + pub start_line: u32, + pub start_col: u32, + pub end_line: u32, + pub end_col: u32, +} + +impl Debug for CodeRegion { + fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result { + write!( + fmt, + "{}:{}:{} - {}:{}", + self.file_name, self.start_line, self.start_col, self.end_line, self.end_col + ) + } +} + +#[derive(Copy, Clone, Debug, PartialEq, TyEncodable, TyDecodable, Hash, HashStable)] +#[derive(TypeFoldable, TypeVisitable)] +pub enum Op { + Subtract, + Add, +} + +impl Op { + pub fn is_add(&self) -> bool { + matches!(self, Self::Add) + } + + pub fn is_subtract(&self) -> bool { + matches!(self, Self::Subtract) + } +} |