go/analysis: a new API for analysis tools
This CL contains just the API, the validate function,
and two example analyses, findcall and pkglemma.
Change-Id: Ia1f2652647050b1e0e15dad8b9ae10cf1a5fbdbc
Synopsis: go-review.googlesource.com/c/tools/+/134935
Design: docs.google.com/document/d/1-azPLXaLgTCKeKDNg0HVMq2ovMlD-e7n1ZHzZVzOlJk
Reviewed-on: https://go-review.googlesource.com/135635
Reviewed-by: Ian Cottrell <iancottrell@google.com>
diff --git a/go/analysis/validate.go b/go/analysis/validate.go
new file mode 100644
index 0000000..7fbb3b5
--- /dev/null
+++ b/go/analysis/validate.go
@@ -0,0 +1,97 @@
+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 != ""
+}
