ipld-eth-server/vendor/golang.org/x/tools/go/analysis/validate.go
2018-09-24 15:39:23 -05:00

98 lines
2.3 KiB
Go

package analysis
import (
"fmt"
"reflect"
"unicode"
)
// Validate reports an error if any of the analyses are misconfigured.
// Checks include:
// - that the name is a valid identifier;
// - that analysis names are unique;
// - that the Requires graph is acylic;
// - that analyses' lemma and output types are unique.
// - that each lemma type is a pointer.
func Validate(analyses []*Analysis) error {
names := make(map[string]bool)
// Map each lemma/output type to its sole generating analysis.
lemmaTypes := make(map[reflect.Type]*Analysis)
outputTypes := make(map[reflect.Type]*Analysis)
// Traverse the Requires graph, depth first.
color := make(map[*Analysis]uint8) // 0=white 1=grey 2=black
var visit func(a *Analysis) error
visit = func(a *Analysis) error {
if a == nil {
return fmt.Errorf("nil *Analysis")
}
if color[a] == 0 { // white
color[a] = 1 // grey
// names
if !validIdent(a.Name) {
return fmt.Errorf("invalid analysis name %q", a)
}
if names[a.Name] {
return fmt.Errorf("duplicate analysis name %q", a)
}
names[a.Name] = true
if a.Doc == "" {
return fmt.Errorf("analysis %q is undocumented", a)
}
// lemma types
for _, t := range a.LemmaTypes {
if t == nil {
return fmt.Errorf("analysis %s has nil LemmaType", a)
}
if prev := lemmaTypes[t]; prev != nil {
return fmt.Errorf("lemma type %s registered by two analyses: %v, %v",
t, a, prev)
}
if t.Kind() != reflect.Ptr {
return fmt.Errorf("%s: lemma type %s is not a pointer", a, t)
}
lemmaTypes[t] = a
}
// output types
if a.OutputType != nil {
if prev := outputTypes[a.OutputType]; prev != nil {
return fmt.Errorf("output type %s registered by two analyses: %v, %v",
a.OutputType, a, prev)
}
outputTypes[a.OutputType] = a
}
// recursion
for i, req := range a.Requires {
if err := visit(req); err != nil {
return fmt.Errorf("%s.Requires[%d]: %v", a.Name, i, err)
}
}
color[a] = 2 // black
}
return nil
}
for _, a := range analyses {
if err := visit(a); err != nil {
return err
}
}
return nil
}
func validIdent(name string) bool {
for i, r := range name {
if !(r == '_' || unicode.IsLetter(r) || i > 0 && unicode.IsDigit(r)) {
return false
}
}
return name != ""
}