rust - https://github.com/rust-lang/rust

Age	Commit message (Collapse)	Author	Lines
2021-03-19	coverage bug fixes and optimization support	Rich Kadel	-1/+1
	Adjusted LLVM codegen for code compiled with `-Zinstrument-coverage` to address multiple, somewhat related issues. Fixed a significant flaw in prior coverage solution: Every counter generated a new counter variable, but there should have only been one counter variable per function. This appears to have bloated .profraw files significantly. (For a small program, it increased the size by about 40%. I have not tested large programs, but there is anecdotal evidence that profraw files were way too large. This is a good fix, regardless, but hopefully it also addresses related issues. Fixes: #82144 Invalid LLVM coverage data produced when compiled with -C opt-level=1 Existing tests now work up to at least `opt-level=3`. This required a detailed analysis of the LLVM IR, comparisons with Clang C++ LLVM IR when compiled with coverage, and a lot of trial and error with codegen adjustments. The biggest hurdle was figuring out how to continue to support coverage results for unused functions and generics. Rust's coverage results have three advantages over Clang's coverage results: 1. Rust's coverage map does not include any overlapping code regions, making coverage counting unambiguous. 2. Rust generates coverage results (showing zero counts) for all unused functions, including generics. (Clang does not generate coverage for uninstantiated template functions.) 3. Rust's unused functions produce minimal stubbed functions in LLVM IR, sufficient for including in the coverage results; while Clang must generate the complete LLVM IR for each unused function, even though it will never be called. This PR removes the previous hack of attempting to inject coverage into some other existing function instance, and generates dedicated instances for each unused function. This change, and a few other adjustments (similar to what is required for `-C link-dead-code`, but with lower impact), makes it possible to support LLVM optimizations. Fixes: #79651 Coverage report: "Unexecuted instantiation:..." for a generic function from multiple crates Fixed by removing the aforementioned hack. Some "Unexecuted instantiation" notices are unavoidable, as explained in the `used_crate.rs` test, but `-Zinstrument-coverage` has new options to back off support for either unused generics, or all unused functions, which avoids the notice, at the cost of less coverage of unused functions. Fixes: #82875 Invalid LLVM coverage data produced with crate brotli_decompressor Fixed by disabling the LLVM function attribute that forces inlining, if `-Z instrument-coverage` is enabled. This attribute is applied to Rust functions with `#[inline(always)], and in some cases, the forced inlining breaks coverage instrumentation and reports.
2020-12-22	Update and improve `rustc_codegen_{llvm,ssa}` docs	Camelid	-10/+8
	These docs were very out of date and misleading. They even said that they codegen'd the AST! For some reason, the `rustc_codegen_ssa::base` docs were exactly identical to the `rustc_codegen_llvm::base` docs. They didn't really make sense, because they had LLVM-specific information even though `rustc_codegen_ssa` is supposed to be somewhat generic. So I removed them as they were misleading.
2020-11-03	[self-profiling] Include the estimated size of each cgu in the profile	Wesley Wiser	-2/+4
	This is helpful when looking for CGUs where the size estimate isn't a good indicator of compilation time. I verified that moving the profiling timer call doesn't affect the results.
2020-10-15	Replace target.target with target and target.ptr_width with target.pointer_width	est31	-1/+1
	Preparation for a subsequent change that replaces rustc_target::config::Config with its wrapped Target. On its own, this commit breaks the build. I don't like making build-breaking commits, but in this instance I believe that it makes review easier, as the "real" changes of this PR can be seen much more easily. Result of running: find compiler/ -type f -exec sed -i -e 's/target\.target$[)\.,; ]$/target\1/g' {} \; find compiler/ -type f -exec sed -i -e 's/target\.target$/target/g' {} \; find compiler/ -type f -exec sed -i -e 's/target.ptr_width/target.pointer_width/g' {} \; ./x.py fmt
2020-09-20	Use as_nanos in bench.rs and base.rs	est31	-1/+1

2020-08-30	mv compiler to compiler/	mark	-0/+205