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| -rw-r--r-- | src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md b/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md index 03c822d4fee..18e0e25c531 100644 --- a/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md +++ b/src/doc/rustc-dev-guide/src/queries/incremental-compilation-in-detail.md @@ -1,4 +1,4 @@ -# Incremental Compilation in detail +# Incremental compilation in detail <!-- toc --> @@ -66,7 +66,7 @@ because it reads the up-to-date version of `Hir(bar)`. Also, we re-run `type_check_item(bar)` because result of `type_of(bar)` might have changed. -## The Problem With The Basic Algorithm: False Positives +## The problem with the basic algorithm: false positives If you read the previous paragraph carefully you'll notice that it says that `type_of(bar)` *might* have changed because one of its inputs has changed. @@ -93,7 +93,7 @@ of examples like this and small changes to the input often potentially affect very large parts of the output binaries. As a consequence, we had to make the change detection system smarter and more accurate. -## Improving Accuracy: The red-green Algorithm +## Improving accuracy: the red-green algorithm The "false positives" problem can be solved by interleaving change detection and query re-evaluation. Instead of walking the graph all the way to the @@ -191,7 +191,7 @@ then itself involve recursively invoking more queries, which can mean we come ba to the `try_mark_green()` algorithm for the dependencies recursively. -## The Real World: How Persistence Makes Everything Complicated +## The real world: how persistence makes everything complicated The sections above described the underlying algorithm for incremental compilation but because the compiler process exits after being finished and @@ -258,7 +258,7 @@ the `LocalId`s within it are still the same. -### Checking Query Results For Changes: HashStable And Fingerprints +### Checking query results for changes: `HashStable` and `Fingerprint`s In order to do red-green-marking we often need to check if the result of a query has changed compared to the result it had during the previous @@ -306,7 +306,7 @@ This approach works rather well but it's not without flaws: their stable equivalents while doing the hashing. -### A Tale Of Two DepGraphs: The Old And The New +### A tale of two `DepGraph`s: the old and the new The initial description of dependency tracking glosses over a few details that quickly become a head scratcher when actually trying to implement things. @@ -344,7 +344,7 @@ new graph is serialized out to disk, alongside the query result cache, and can act as the previous dep-graph in a subsequent compilation session. -### Didn't You Forget Something?: Cache Promotion +### Didn't you forget something?: cache promotion The system described so far has a somewhat subtle property: If all inputs of a dep-node are green then the dep-node itself can be marked as green without @@ -374,7 +374,7 @@ the result cache doesn't unnecessarily shrink again. -# Incremental Compilation and the Compiler Backend +# Incremental compilation and the compiler backend The compiler backend, the part involving LLVM, is using the query system but it is not implemented in terms of queries itself. As a consequence it does not @@ -406,7 +406,7 @@ would save. -## Query Modifiers +## Query modifiers The query system allows for applying [modifiers][mod] to queries. These modifiers affect certain aspects of how the system treats the query with @@ -472,7 +472,7 @@ respect to incremental compilation: [mod]: ../query.html#adding-a-new-kind-of-query -## The Projection Query Pattern +## The projection query pattern It's interesting to note that `eval_always` and `no_hash` can be used together in the so-called "projection query" pattern. It is often the case that there is @@ -516,7 +516,7 @@ because we have the projections to take care of keeping things green as much as possible. -# Shortcomings of the Current System +# Shortcomings of the current system There are many things that still can be improved. |