go/analysis: validate: report duplicates among analyzers (roots)
Duplicate root analyzers caused duplicate flag registration and other problems.
Change-Id: Id0c2761529c57ed1f9a63b669e62401ebf035cc2
Reviewed-on: https://go-review.googlesource.com/c/141159
Reviewed-by: Michael Matloob <matloob@golang.org>
diff --git a/go/analysis/validate.go b/go/analysis/validate.go
index dd9d25b..6e6cf49 100644
--- a/go/analysis/validate.go
+++ b/go/analysis/validate.go
@@ -20,14 +20,20 @@
factTypes := make(map[reflect.Type]*Analyzer)
// Traverse the Requires graph, depth first.
- color := make(map[*Analyzer]uint8) // 0=white 1=grey 2=black
+ const (
+ white = iota
+ grey
+ black
+ finished
+ )
+ color := make(map[*Analyzer]uint8)
var visit func(a *Analyzer) error
visit = func(a *Analyzer) error {
if a == nil {
return fmt.Errorf("nil *Analyzer")
}
- if color[a] == 0 { // white
- color[a] = 1 // grey
+ if color[a] == white {
+ color[a] = grey
// names
if !validIdent(a.Name) {
@@ -64,7 +70,7 @@
return fmt.Errorf("%s.Requires[%d]: %v", a.Name, i, err)
}
}
- color[a] = 2 // black
+ color[a] = black
}
return nil
@@ -75,6 +81,16 @@
}
}
+ // Reject duplicates among analyzers.
+ // Precondition: color[a] == black.
+ // Postcondition: color[a] == finished.
+ for _, a := range analyzers {
+ if color[a] == finished {
+ return fmt.Errorf("duplicate analyzer: %s", a.Name)
+ }
+ color[a] = finished
+ }
+
return nil
}
