+/// The different settings that the `-Z instrument-coverage` flag can have.
+///
+/// Coverage instrumentation now supports combining `-Z instrument-coverage`
+/// with compiler and linker optimization (enabled with `-O` or `-C opt-level=1`
+/// and higher). Nevertheless, there are many variables, depending on options
+/// selected, code structure, and enabled attributes. If errors are encountered,
+/// either while compiling or when generating `llvm-cov show` reports, consider
+/// lowering the optimization level, including or excluding `-C link-dead-code`,
+/// or using `-Z instrument-coverage=except-unused-functions` or `-Z
+/// instrument-coverage=except-unused-generics`.
+///
+/// Note that `ExceptUnusedFunctions` means: When `mapgen.rs` generates the
+/// coverage map, it will not attempt to generate synthetic functions for unused
+/// (and not code-generated) functions (whether they are generic or not). As a
+/// result, non-codegenned functions will not be included in the coverage map,
+/// and will not appear, as covered or uncovered, in coverage reports.
+///
+/// `ExceptUnusedGenerics` will add synthetic functions to the coverage map,
+/// unless the function has type parameters.
+#[derive(Clone, Copy, PartialEq, Hash, Debug)]
+pub enum InstrumentCoverage {
+ /// Default `-Z instrument-coverage` or `-Z instrument-coverage=statement`
+ All,
+ /// `-Z instrument-coverage=except-unused-generics`
+ ExceptUnusedGenerics,
+ /// `-Z instrument-coverage=except-unused-functions`
+ ExceptUnusedFunctions,
+ /// `-Z instrument-coverage=off` (or `no`, etc.)
+ Off,
+}
+