Nicholas Nethercote 5b54363961 Optimize the code produced by derive(Debug). ... This commit adds new methods that combine sequences of existing formatting methods. - `Formatter::debug_{tuple,struct}_field[12345]_finish`, equivalent to a `Formatter::debug_{tuple,struct}` + N x `Debug{Tuple,Struct}::field` + `Debug{Tuple,Struct}::finish` call sequence. - `Formatter::debug_{tuple,struct}_fields_finish` is similar, but can handle any number of fields by using arrays. These new methods are all marked as `doc(hidden)` and unstable. They are intended for the compiler's own use. Special-casing up to 5 fields gives significantly better performance results than always using arrays (as was tried in #95637). The commit also changes the `Debug` deriving code to use these new methods. For example, where the old `Debug` code for a struct with two fields would be like this: ``` fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { match *self { Self { f1: ref __self_0_0, f2: ref __self_0_1, } => { let debug_trait_builder = &mut ::core::fmt::Formatter::debug_struct(f, "S2"); let _ = ::core::fmt::DebugStruct::field(debug_trait_builder, "f1", &&(*__self_0_0)); let _ = ::core::fmt::DebugStruct::field(debug_trait_builder, "f2", &&(*__self_0_1)); ::core::fmt::DebugStruct::finish(debug_trait_builder) } } } ``` the new code is like this: ``` fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { match *self { Self { f1: ref __self_0_0, f2: ref __self_0_1, } => ::core::fmt::Formatter::debug_struct_field2_finish( f, "S2", "f1", &&(*__self_0_0), "f2", &&(*__self_0_1), ), } } ``` This shrinks the code produced for `Debug` instances considerably, reducing compile times and binary sizes. Co-authored-by: Scott McMurray <scottmcm@users.noreply.github.com>		2022-06-24 09:40:15 +10:00
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src	Optimize the code produced by derive(Debug).	2022-06-24 09:40:15 +10:00
Cargo.toml	Update sha1, sha2, and md5 dependencies	2022-02-13 15:29:01 -06:00