rust/compiler/rustc_codegen_llvm
Guillaume Gomez 526c67f37b
Rollup merge of #131829 - Zalathar:goodbye-zprofile, r=chenyukang
Remove support for `-Zprofile` (gcov-style coverage instrumentation)

Tracking issue: #42524

MCP: https://github.com/rust-lang/compiler-team/issues/798

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This PR removes the unstable `-Zprofile` flag, which enables ”gcov-style” coverage instrumentation, along with its associated `-Zprofile-emit` configuration flag.

(The profile flag predates and is almost entirely separate from the stable `-Cinstrument-coverage` flag.)

Notably, the `-Zprofile` flag:
- Is largely untested in-tree, having only one run-make test that does not check whether its output is correct or useful.
- Has no known maintainer.
- Has seen no push towards stabilization.
- Has at least one severe regression reported in 2022 that apparently remains unaddressed.
  - #100125
- Is confusingly named, since it appears to be more about coverage than performance profiling, and has nothing to do with PGO.
- Is fundamentally limited by relying on counters auto-inserted by LLVM, with no knowledge of Rust beyond debuginfo.
2024-11-02 03:08:49 +08:00
..
src Rollup merge of #131829 - Zalathar:goodbye-zprofile, r=chenyukang 2024-11-02 03:08:49 +08:00
Cargo.toml compiler: Factor rustc_target::abi out of cg_llvm 2024-10-08 18:24:56 -07:00
messages.ftl codegen_ssa: consolidate tied feature checking 2024-09-24 15:48:49 +01:00
README.md mv compiler to compiler/ 2020-08-30 18:45:07 +03:00

The codegen crate contains the code to convert from MIR into LLVM IR, and then from LLVM IR into machine code. In general it contains code that runs towards the end of the compilation process.

For more information about how codegen works, see the rustc dev guide.