go/analysis: document that facts are gob encoded in one gulp

adonovan · gopherbot · commit aa9f4b2f3d57 · 2022-12-02T22:17:04.000Z
Fixes golang/go#54661 Change-Id: Iddae4d2ab54fc0527e060922351c52eec07c78c0 Reviewed-on: https://go-review.googlesource.com/c/tools/+/454564 TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Alan Donovan <adonovan@google.com> Run-TryBot: Alan Donovan <adonovan@google.com> gopls-CI: kokoro <noreply+kokoro@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
diff --git a/go/analysis/doc.go b/go/analysis/doc.go
@@ -244,6 +244,9 @@ if the default encoding is unsuitable. Facts should be stateless.
 Because serialized facts may appear within build outputs, the gob encoding
 of a fact must be deterministic, to avoid spurious cache misses in
 build systems that use content-addressable caches.
+The driver makes a single call to the gob encoder for all facts
+exported by a given analysis pass, so that the topology of
+shared data structures referenced by multiple facts is preserved.
 
 The Pass type has functions to import and export facts,
 associated either with an object or with a package:
