From 51d692cf7709de563cac6b5ee0080b8adf96f1df Mon Sep 17 00:00:00 2001 From: Rich Kadel Date: Thu, 27 Aug 2020 14:13:04 -0700 Subject: Tools, tests, and experimenting with MIR-derived coverage counters Adds a new mir_dump output file in HTML/CSS to visualize code regions and the MIR features that they came from (including overlapping spans). See example below: Includes a basic, MIR-block-based implementation of coverage injection, available via `-Zexperimental-coverage`. This implementation has known flaws and omissions, but is simple enough to validate the new tools and tests. The existing `-Zinstrument-coverage` option currently enables function-level coverage only, which at least appears to generate accurate coverage reports at that level. Experimental coverage is not accurate at this time. When branch coverage works as intended, the `-Zexperimental-coverage` option should be removed. This PR replaces the bulk of PR #75828, with the remaining parts of that PR distributed among other separate and indentpent PRs. This PR depends on three of those other PRs: #76000, #76002, and Rust compiler MCP rust-lang/compiler-team#278 Relevant issue: #34701 - Implement support for LLVMs code coverage instrumentation ![Screen-Recording-2020-08-21-at-2](https://user-images.githubusercontent.com/3827298/90972923-ff417880-e4d1-11ea-92bb-8713c6198f6d.gif) --- compiler/rustc_session/src/config.rs | 4 ++++ compiler/rustc_session/src/options.rs | 5 +++++ 2 files changed, 9 insertions(+) (limited to 'compiler/rustc_session/src') diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs index 6861314a88f..7db2557453b 100644 --- a/compiler/rustc_session/src/config.rs +++ b/compiler/rustc_session/src/config.rs @@ -1724,6 +1724,10 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options { ); } + if debugging_opts.experimental_coverage { + debugging_opts.instrument_coverage = true; + } + if debugging_opts.instrument_coverage { if cg.profile_generate.enabled() || cg.profile_use.is_some() { early_error( diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index a28c17917df..44a18bd7831 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -890,6 +890,11 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options, all statements)."), emit_stack_sizes: bool = (false, parse_bool, [UNTRACKED], "emit a section containing stack size metadata (default: no)"), + experimental_coverage: bool = (false, parse_bool, [TRACKED], + "enable and extend the `-Z instrument-coverage` function-level coverage \ + feature, adding additional experimental (likely inaccurate) counters and \ + code regions (used by `rustc` compiler developers to test new coverage \ + counter placements) (default: no)"), fewer_names: bool = (false, parse_bool, [TRACKED], "reduce memory use by retaining fewer names within compilation artifacts (LLVM-IR) \ (default: no)"), -- cgit 1.4.1-3-g733a5