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Update CoverageMappingFormat Support to Version6

Version 5 adds Branch Regions which are a prerequisite for branch coverage.
Version 6 can use the zeroth filename as prefix for other relative files.
This commit is contained in:
Arpad Borsos 2021-10-19 11:09:43 +02:00 committed by Rich Kadel
parent 7b3cd075bb
commit 566ad8da45
6 changed files with 66 additions and 23 deletions

View file

@ -17,10 +17,10 @@ use tracing::debug;
/// Generates and exports the Coverage Map.
///
/// This Coverage Map complies with Coverage Mapping Format version 4 (zero-based encoded as 3),
/// as defined at [LLVM Code Coverage Mapping Format](https://github.com/rust-lang/llvm-project/blob/rustc/11.0-2020-10-12/llvm/docs/CoverageMappingFormat.rst#llvm-code-coverage-mapping-format)
/// and published in Rust's November 2020 fork of LLVM. This version is supported by the LLVM
/// coverage tools (`llvm-profdata` and `llvm-cov`) bundled with Rust's fork of LLVM.
/// This Coverage Map complies with Coverage Mapping Format version 5 (zero-based encoded as 4),
/// as defined at [LLVM Code Coverage Mapping Format](https://github.com/rust-lang/llvm-project/blob/rustc/13.0-2021-09-30/llvm/docs/CoverageMappingFormat.rst#llvm-code-coverage-mapping-format).
/// This version is supported by the LLVM coverage tools (`llvm-profdata` and `llvm-cov`)
/// bundled with Rust's fork of LLVM.
///
/// Consequently, Rust's bundled version of Clang also generates Coverage Maps compliant with
/// the same version. Clang's implementation of Coverage Map generation was referenced when
@ -30,12 +30,12 @@ use tracing::debug;
pub fn finalize<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>) {
let tcx = cx.tcx;
// Ensure LLVM supports Coverage Map Version 4 (encoded as a zero-based value: 3).
// If not, the LLVM Version must be less than 11.
let version = coverageinfo::mapping_version();
if version != 3 {
tcx.sess.fatal("rustc option `-Z instrument-coverage` requires LLVM 11 or higher.");
}
// While our bundled LLVM might support Coverage Map Version 6
// (encoded as a zero-based value: 5), we clamp that to Version 5,
// as Version 6 would require us to use the 0-th filename as a path prefix
// for all other relative paths, which we don't take advantage of right now.
let _version = coverageinfo::mapping_version();
let version = 4;
debug!("Generating coverage map for CodegenUnit: `{}`", cx.codegen_unit.name());