chore: go mod vendor / tidy

vendor/github.com/mmcloughlin/avo/build/error.go

@@ -0,0 +1,91 @@
+package build
+
+import (
+	"errors"
+	"fmt"
+	"log"
+
+	"github.com/mmcloughlin/avo/internal/stack"
+	"github.com/mmcloughlin/avo/src"
+)
+
+// Error represents an error during building, optionally tagged with the position at which it happened.
+type Error struct {
+	Position src.Position
+	Err      error
+}
+
+// exterr constructs an Error with position derived from the first frame in the
+// call stack outside this package.
+func exterr(err error) Error {
+	e := Error{Err: err}
+	if f := stack.ExternalCaller(); f != nil {
+		e.Position = src.FramePosition(*f).Relwd()
+	}
+	return e
+}
+
+func (e Error) Error() string {
+	msg := e.Err.Error()
+	if e.Position.IsValid() {
+		return e.Position.String() + ": " + msg
+	}
+	return msg
+}
+
+// ErrorList is a collection of errors for a source file.
+type ErrorList []Error
+
+// Add appends an error to the list.
+func (e *ErrorList) Add(err Error) {
+	*e = append(*e, err)
+}
+
+// AddAt appends an error at position p.
+func (e *ErrorList) AddAt(p src.Position, err error) {
+	e.Add(Error{p, err})
+}
+
+// addext appends an error to the list, tagged with the first external position
+// outside this package.
+func (e *ErrorList) addext(err error) {
+	e.Add(exterr(err))
+}
+
+// Err returns an error equivalent to this error list.
+// If the list is empty, Err returns nil.
+func (e ErrorList) Err() error {
+	if len(e) == 0 {
+		return nil
+	}
+	return e
+}
+
+// Error implements the error interface.
+func (e ErrorList) Error() string {
+	switch len(e) {
+	case 0:
+		return "no errors"
+	case 1:
+		return e[0].Error()
+	}
+	return fmt.Sprintf("%s (and %d more errors)", e[0], len(e)-1)
+}
+
+// LogError logs a list of errors, one error per line, if the err parameter is
+// an ErrorList. Otherwise it just logs the err string. Reports at most max
+// errors, or unlimited if max is 0.
+func LogError(l *log.Logger, err error, max int) {
+	var list ErrorList
+	if errors.As(err, &list) {
+		for i, e := range list {
+			if max > 0 && i == max {
+				l.Print("too many errors")
+				return
+			}
+			l.Printf("%s\n", e)
+		}
+	} else if err != nil {
+		l.Printf("%s\n", err)
+	}
+}