Commits on May 19, 2017

1. Add test name filtering to 'mach test-stylo'

   

   SimonSapin committed May 19, 2017
   389073b

2. Look at size_of ParsedDeclaration… Yeah, we’ll need to fix that.

   

   SimonSapin committed May 19, 2017
   5c57ff8

3. Box large components of Longhands structs.

   

   SimonSapin committed May 19, 2017
   e4f2413

4. Avoid returning / passing around a huge ParsedDeclaration type …

   This enum type used to contain the result of parsing
   one CSS source declaration (`name: value;`) and expanding shorthands.
   Enum types are as big as the biggest of their variant (plus discriminant),
   which was quite big because some shorthands
   expand to many longhand properties.
   This type was returned through many functions and methods,
   wrapped and rewrapped in `Result` with different error types.
   This presumably caused significant `memmove` traffic.
   
   Instead, we now allocate an `ArrayVec` on the stack
   and pass `&mut` references to it for various functions to push into it.
   This type is also very big, but we never move it.
   
   We still use an intermediate data structure because we sometimes decide
   after shorthand expansion that a declaration is invalid after all
   and that we’re gonna drop it.
   Only later do we push to a `PropertyDeclarationBlock`,
   with an entire `ArrayVec` or nothing.
   
   In future work we can try to avoid a large stack-allocated array,
   and instead writing directly to the heap allocation
   of the `Vec` inside `PropertyDeclarationBlock`.
   However this is tricky:
   we need to preserve this "all or nothing" aspect
   of parsing one source declaration,
   and at the same time we want to make it as little error-prone as possible
   for the various call sites.
   `PropertyDeclarationBlock` curently does property deduplication
   incrementally: as each `PropertyDeclaration` is pushed,
   we check if an existing declaration of the same property exists
   and if so overwrite it.
   To get rid of the stack allocated array we’d need to somehow
   deduplicate separately after pushing multiple `PropertyDeclaration`.

   

   SimonSapin committed May 19, 2017
   d2be523

5. Use Vec::reserve in PropertyDeclarationBlock

   

   SimonSapin committed May 19, 2017
   cb8f778

6. Work around CI bustage

   

   SimonSapin committed May 19, 2017

   Loading status checks…
   341fc54