rust/compiler/rustc_codegen_llvm/src/debuginfo, branch 1.52.0

Auto merge of #82285 - nhwn:nonzero-debug, r=nagisa

2021-03-07T20:23:23+00:00

Use u32 over Option in DebugLoc ~~Changes `Option` fields in `DebugLoc` to `Option`. Since the respective fields (`line` and `col`) are guaranteed to be 1-based, this layout optimization is a freebie.~~ EDIT: Changes `Option` fields in `DebugLoc` to `u32`. As `@bugadani` pointed out, an `Option` is probably an unnecessary layer of abstraction since the `None` variant is always used as `UNKNOWN_LINE_NUMBER` (which is just `0`). Also, `SourceInfo` in `metadata.rs` already uses a `u32` instead of an `Option` to encode the same information, so I think this change is warranted. Since `@jyn514` raised some concerns over measuring performance in a similar PR (#82255), does this need a perf run?

Box generator-related Body fields

2021-03-01T07:32:49+00:00

Rollup merge of #82057 - upsuper-forks:cstr, r=davidtwco,wesleywiser

2021-02-27T01:34:21+00:00

Replace const_cstr with cstr crate This PR replaces the `const_cstr` macro inside `rustc_data_structures` with `cstr` macro from [cstr](https://crates.io/crates/cstr) crate. The two macros basically serve the same purpose, which is to generate `&'static CStr` from a string literal. `cstr` is better because it validates the literal at compile time, while the existing `const_cstr` does it at runtime when `debug_assertions` is enabled. In addition, the value `cstr` generates can be used in constant context (which is seemingly not needed anywhere currently, though).

fix review

2021-02-25T01:21:12+00:00

replaced some map_or with map_or_else

2021-02-23T23:43:35+00:00

nhwn: use plain u32 in DebugLoc

2021-02-20T17:46:58+00:00

nhwn: use Option in DebugLoc

2021-02-20T17:46:50+00:00

Set path of the compile unit to the source directory

2021-02-14T15:12:14+00:00

As part of the effort to implement split dwarf debug info, we ended up setting the compile unit location to the output directory rather than the source directory. Furthermore, it seems like we failed to remap the prefixes for this as well! The desired behaviour is to instead set the `DW_AT_GNU_dwo_name` to a path relative to compiler's working directory. This still allows debuggers to find the split dwarf files, while not changing the behaviour of the code that is compiling with regular debug info, and not changing the compiler's behaviour with regards to reproducibility. Fixes #82074

Replace const_cstr with cstr crate

2021-02-13T22:45:35+00:00

Rollup merge of #79570 - alexcrichton:split-debuginfo, r=bjorn3

2021-01-29T00:17:20+00:00

rustc: Stabilize `-Zrun-dsymutil` as `-Csplit-debuginfo` This commit adds a new stable codegen option to rustc, `-Csplit-debuginfo`. The old `-Zrun-dsymutil` flag is deleted and now subsumed by this stable flag. Additionally `-Zsplit-dwarf` is also subsumed by this flag but still requires `-Zunstable-options` to actually activate. The `-Csplit-debuginfo` flag takes one of three values: * `off` - This indicates that split-debuginfo from the final artifact is not desired. This is not supported on Windows and is the default on Unix platforms except macOS. On macOS this means that `dsymutil` is not executed. * `packed` - This means that debuginfo is desired in one location separate from the main executable. This is the default on Windows (`*.pdb`) and macOS (`*.dSYM`). On other Unix platforms this subsumes `-Zsplit-dwarf=single` and produces a `*.dwp` file. * `unpacked` - This means that debuginfo will be roughly equivalent to object files, meaning that it's throughout the build directory rather than in one location (often the fastest for local development). This is not the default on any platform and is not supported on Windows. Each target can indicate its own default preference for how debuginfo is handled. Almost all platforms default to `off` except for Windows and macOS which default to `packed` for historical reasons. Some equivalencies for previous unstable flags with the new flags are: * `-Zrun-dsymutil=yes` -> `-Csplit-debuginfo=packed` * `-Zrun-dsymutil=no` -> `-Csplit-debuginfo=unpacked` * `-Zsplit-dwarf=single` -> `-Csplit-debuginfo=packed` * `-Zsplit-dwarf=split` -> `-Csplit-debuginfo=unpacked` Note that `-Csplit-debuginfo` still requires `-Zunstable-options` for non-macOS platforms since split-dwarf support was *just* implemented in rustc. There's some more rationale listed on #79361, but the main gist of the motivation for this commit is that `dsymutil` can take quite a long time to execute in debug builds and provides little benefit. This means that incremental compile times appear that much worse on macOS because the compiler is constantly running `dsymutil` over every single binary it produces during `cargo build` (even build scripts!). Ideally rustc would switch to not running `dsymutil` by default, but that's a problem left to get tackled another day. Closes #79361