implements: add a textual report

Add simple reporting functionality to the implements package that is
intended to mimic the output of the current contrib/apicompare.py
script.

Signed-off-by: John Mulligan <jmulligan@redhat.com>

contrib/implements/internal/implements/report.go

@@ -0,0 +1,98 @@
+package implements
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// ReportOptions is a common set of options for reports.
+type ReportOptions struct {
+	List     bool
+	Annotate bool
+}
+
+// Reporter is a common interface to report on the "implements"
+// analysis.
+type Reporter interface {
+	// Report reports on the given (sub)package with the given inspector's
+	// contents.
+	Report(string, *Inspector) error
+	// Done flushes any buffered state between calls to Report.
+	Done() error
+}
+
+// TextReport implements a streaming plain-text output report.
+type TextReport struct {
+	o ReportOptions
+}
+
+// NewTextReport creates a new TextReport.
+func NewTextReport(o ReportOptions) *TextReport {
+	return &TextReport{o}
+}
+
+// Report on the given code inspector.
+func (r *TextReport) Report(name string, ii *Inspector) error {
+	o := r.o
+	packageLabel := strings.ToUpper(name)
+
+	ii.update()
+
+	found := len(ii.found)
+	total := len(ii.expected)
+	fmt.Printf(
+		"%s functions covered: %d/%d : %v%%\n",
+		packageLabel,
+		found,
+		total,
+		(100*found)/total)
+	missing := total - found - ii.deprecatedMissing
+	fmt.Printf(
+		"%s functions missing: %d/%d : %v%%\n",
+		packageLabel,
+		missing,
+		total,
+		(100*missing)/total)
+	fmt.Printf(
+		"  (note missing count does not include deprecated functions in ceph)\n")
+
+	if !o.List {
+		return nil
+	}
+	sort.Sort(ii.expected)
+	for _, cf := range ii.expected {
+		if flags, ok := ii.found[cf.Name]; ok {
+			tags := ""
+			if o.Annotate {
+				if flags&isCalled == isCalled {
+					tags += " called"
+				}
+				if flags&isDocumented == isDocumented {
+					tags += " documented"
+				}
+				if flags&isDeprecated == isDeprecated {
+					tags += " deprecated"
+				}
+				if tags != "" {
+					tags = " (" + strings.TrimSpace(tags) + ")"
+				}
+			}
+			fmt.Printf("  Covered: %s%s\n", cf.Name, tags)
+		}
+	}
+	for _, cf := range ii.expected {
+		if _, ok := ii.found[cf.Name]; ok {
+			continue
+		}
+		d := ""
+		if o.Annotate && cf.isDeprecated() {
+			d = " (deprecated)"
+		}
+		fmt.Printf("  Missing: %s%s\n", cf.Name, d)
+	}
+	return nil
+}
+
+// Done updating report with inspectors.
+func (*TextReport) Done() error { return nil }