strip prefix of temporary file names when it exceeds filesystem name length limit #145005
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This method is also used for generating output files in various places. Mangling the name of output files would break cargo and other build tools that pre-generate the expected filenames based on |
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@bjorn3 would it be more appropriate to put the filename stripping in temp_path_ext_for_cgu ? those files if I understand correctly are temporary and unlinked after the rustc invocation. |
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r? bjorn3 feel free to reassign |
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| filename[..stripped_len].hash(&mut hasher); | ||
| let hash = hasher.finish::<Hash64>(); | ||
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| path.set_file_name(format!("{:x}-{}", hash, &filename[stripped_len..])); |
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The start of the filename has more useful information, but we do absolutely need to preserve file extensions (plural: eg .rcgu.o) for correctness and it isn't trivial to distinguish between file extensions and normal dot separated filename components. So I guess the current implementation is good enough.
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...-large-large-large-large-large-large-large-large-large-large-large-large-large-crate-name.rs
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…length limit When doing lto, rustc generates filenames that are concatenating many information. In the case of this testcase, it is concatenating crate name and rust file name, plus some hash, and the extension. In some other cases it will concatenate even more information reducing the maximum effective crate name to about 110 chars on linux filesystems where filename max length is 255 This commit is ensuring that the temporary file names are limited in size, while still reasonabily ensuring the unicity (with hashing of the stripped part)
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strip prefix of temporary file names when it exceeds filesystem name length limit When doing lto, rustc generates filenames that are concatenating many information. In the case of this testcase, it is concatenating crate name and rust file name, plus some hash, and the extension. In some other cases it will concatenate even more information reducing the maximum effective crate name to about 110 chars on linux filesystems where filename max length is 255 This commit is ensuring that the temporary file names are limited in size, while still reasonably ensuring the unicity (with hashing of the stripped part) Fix: rust-lang#49914
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Rollup of 13 pull requests Successful merges: - #122661 (Change the desugaring of `assert!` for better error output) - #142372 (Improve `--remap-path-prefix` documentation) - #143075 (compiler: Allow `extern "interrupt" fn() -> !`) - #145005 (strip prefix of temporary file names when it exceeds filesystem name length limit) - #145065 (resolve: Introduce `RibKind::Block`) - #145120 (llvm: Accept new LLVM lifetime format) - #145189 (Weekly `cargo update`) - #145261 (Improve tracing in bootstrap) - #145266 (Reduce some queries around associated items) - #145299 (doc test: fix mpsc.rs try_send doc test) - #145331 (Make std use the edition 2024 prelude) - #145353 (bootstrap: Fix jemalloc 64K page support for aarch64 tools) - #145361 (Suppress wrapper suggestion when expected and actual ty are the same adt and the variant is unresolved) Failed merges: - #145324 (Rename and document `ONLY_HOSTS` in bootstrap) - #145372 (resolve: Miscellaneous cleanups) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup of 13 pull requests Successful merges: - #122661 (Change the desugaring of `assert!` for better error output) - #142372 (Improve `--remap-path-prefix` documentation) - #143075 (compiler: Allow `extern "interrupt" fn() -> !`) - #145005 (strip prefix of temporary file names when it exceeds filesystem name length limit) - #145065 (resolve: Introduce `RibKind::Block`) - #145120 (llvm: Accept new LLVM lifetime format) - #145189 (Weekly `cargo update`) - #145261 (Improve tracing in bootstrap) - #145266 (Reduce some queries around associated items) - #145299 (doc test: fix mpsc.rs try_send doc test) - #145331 (Make std use the edition 2024 prelude) - #145353 (bootstrap: Fix jemalloc 64K page support for aarch64 tools) - #145361 (Suppress wrapper suggestion when expected and actual ty are the same adt and the variant is unresolved) Failed merges: - #145324 (Rename and document `ONLY_HOSTS` in bootstrap) - #145372 (resolve: Miscellaneous cleanups) r? `@ghost` `@rustbot` modify labels: rollup
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When doing lto, rustc generates filenames that are concatenating many information.
In the case of this testcase, it is concatenating crate name and rust file name, plus some hash, and the extension. In some other cases it will concatenate even more information reducing the maximum effective crate name to about 110 chars on linux filesystems where filename max length is 255
This commit is ensuring that the temporary file names are limited in size, while still reasonably ensuring the unicity (with hashing of the stripped part)
Fix: #49914