rust/src/librustc_codegen_ssa/coverageinfo, branch try

mv compiler to compiler/

2020-08-30T15:45:07+00:00

Moved coverage counter injection from BasicBlock to Statement.

2020-08-19T04:06:45+00:00

Completes support for coverage in external crates

2020-08-04T18:06:54+00:00

The prior PR corrected for errors encountered when trying to generate the coverage map on source code inlined from external crates (including macros and generics) by avoiding adding external DefIds to the coverage map. This made it possible to generate a coverage report including external crates, but the external crate coverage was incomplete (did not include coverage for the DefIds that were eliminated. The root issue was that the coverage map was converting Span locations to source file and locations, using the SourceMap for the current crate, and this would not work for spans from external crates (compliled with a different SourceMap). The solution was to convert the Spans to filename and location during MIR generation instead, so precompiled external crates would already have the correct source code locations embedded in their MIR, when imported into another crate.

Rust function-level coverage now works on external crates

2020-07-30T19:25:39+00:00

Fixed a known issue in the coverage map where some regions had nonsensical source code locations. External crate functions are already included in their own coverage maps, per library, and don't need to also be added to the importing crate's coverage map. (In fact, their source start and end byte positions are not relevant to the importing crate's SourceMap.) The fix was to simply skip trying to add imported coverage info to the coverage map if the instrumented function is not "local". The injected counters are still relevant, however, and the LLVM `instrprof.increment` intrinsic call parameters will map those counters to the external crates' coverage maps, when generating runtime coverage data.

Moved structs/enums with repr(C) to LLVM types into ffi.rs crates

2020-07-29T15:22:17+00:00

Some were in librustc_codegen_llvm, but others are not tied to LLVM, so I put them in a new crate: librustc_codegen_ssa/coverageinfo/ffi.rs

FunctionCoverage: improve type checking with newtype_index types

2020-07-29T00:45:58+00:00

Refactor MIR coverage instrumentation

2020-07-28T22:08:19+00:00

Lays a better foundation for injecting more counters in each function.

Fixed coverage map issues; better aligned with LLVM APIs

2020-07-25T14:39:51+00:00

Found some problems with the coverage map encoding when testing with more than one counter per function. While debugging, I realized some better ways to structure the Rust implementation of the coverage mapping generator. I refactored somewhat, resulting in less code overall, expanded coverage of LLVM Coverage Map capabilities, and much closer alignment with LLVM data structures, APIs, and naming. This should be easier to follow and easier to maintain.

Generating the coverage map

2020-07-17T18:49:35+00:00

rustc now generates the coverage map and can support (limited) coverage report generation, at the function level. Example: $ BUILD=$HOME/rust/build/x86_64-unknown-linux-gnu $ $BUILD/stage1/bin/rustc -Zinstrument-coverage \ $HOME/rust/src/test/run-make-fulldeps/instrument-coverage/main.rs $ LLVM_PROFILE_FILE="main.profraw" ./main called $ $BUILD/llvm/bin/llvm-profdata merge -sparse main.profraw -o main.profdata $ $BUILD/llvm/bin/llvm-cov show --instr-profile=main.profdata main 1| 1|pub fn will_be_called() { 2| 1| println!("called"); 3| 1|} 4| | 5| 0|pub fn will_not_be_called() { 6| 0| println!("should not have been called"); 7| 0|} 8| | 9| 1|fn main() { 10| 1| let less = 1; 11| 1| let more = 100; 12| 1| 13| 1| if less < more { 14| 1| will_be_called(); 15| 1| } else { 16| 1| will_not_be_called(); 17| 1| } 18| 1|}

add spans to injected coverage counters

2020-06-29T19:31:25+00:00

added regions with counter expressions and counters. Added codegen_llvm/coverageinfo mod for upcoming coverage map Move coverage region collection to CodegenCx finalization Moved from `query coverageinfo` (renamed from `query coverage_data`), as discussed in the PR at: https://github.com/rust-lang/rust/pull/73684#issuecomment-649882503 Address merge conflict in MIR instrument_coverage test The MIR test output format changed for int types. moved debug messages out of block.rs This makes the block.rs calls to add coverage mapping data to the CodegenCx much more concise and readable. move coverage intrinsic handling into llvm impl I realized that having half of the coverage intrinsic handling in `rustc_codegen_ssa` and half in `rustc_codegen_llvm` meant that any non-llvm backend would be bound to the same decisions about how the coverage-related MIR terminators should be handled. To fix this, I moved the non-codegen portion of coverage intrinsic handling into its own trait, and implemented it in `rustc_codegen_llvm` alongside `codegen_intrinsic_call`. I also added the (required?) stubs for the new intrinsics to `IntrepretCx::emulate_intrinsic()`, to ensure calls to this function do not fail if called with these new but known intrinsics. address PR Feedback on 28 June 2020 2:48pm PDT