Revert "godoc: skip build tag annotations when displaying examples"

This reverts commit faa8a71ab532725a7fd9d901a97f74c5038c409b.

Reason for revert: +build tag in test causes build to fail :(

Change-Id: I8942a6dcc29faaceada23b63ba80ea881b3b2ca6
Reviewed-on: https://go-review.googlesource.com/126195
Reviewed-by: Andrew Bonventre <andybons@golang.org>
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/godoc/godoc.go b/godoc/godoc.go
index 0acb49b..f191a9d 100644
--- a/godoc/godoc.go
+++ b/godoc/godoc.go
@@ -666,7 +666,6 @@
 		play := ""
 		if eg.Play != nil && p.ShowPlayground {
 			var buf bytes.Buffer
-			eg.Play.Comments = filterOutBuildAnnotations(eg.Play.Comments)
 			if err := format.Node(&buf, info.FSet, eg.Play); err != nil {
 				log.Print(err)
 			} else {
@@ -695,23 +694,6 @@
 	return buf.String()
 }
 
-func filterOutBuildAnnotations(cg []*ast.CommentGroup) []*ast.CommentGroup {
-	if len(cg) == 0 {
-		return cg
-	}
-
-	for i := range cg {
-		if !strings.HasPrefix(cg[i].Text(), "+build ") {
-			// Found the first non-build tag, return from here until the end
-			// of the slice.
-			return cg[i:]
-		}
-	}
-
-	// There weren't any non-build tags, return an empty slice.
-	return []*ast.CommentGroup{}
-}
-
 // example_nameFunc takes an example function name and returns its display
 // name. For example, "Foo_Bar_quux" becomes "Foo.Bar (Quux)".
 func (p *Presentation) example_nameFunc(s string) string {
diff --git a/godoc/godoc_test.go b/godoc/godoc_test.go
index 3c21849..c1d631c 100644
--- a/godoc/godoc_test.go
+++ b/godoc/godoc_test.go
@@ -321,48 +321,3 @@
 		}
 	}
 }
-
-func TestFilterOutBuildAnnotations(t *testing.T) {
-	src := []byte(`
-// +build !foo
-// +build !anothertag
-
-// non-tag comment
-
-package foo
-
-func bar() int {
-	return 42
-}`)
-
-	fset := token.NewFileSet()
-	af, err := parser.ParseFile(fset, "foo.go", src, parser.ParseComments)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	var found bool
-	for _, cg := range af.Comments {
-		if strings.HasPrefix(cg.Text(), "+build ") {
-			found = true
-			break
-		}
-	}
-	if !found {
-		t.Errorf("TestFilterOutBuildAnnotations is broken: missing build tag in test input")
-	}
-
-	found = false
-	for _, cg := range filterOutBuildAnnotations(af.Comments) {
-		if strings.HasPrefix(cg.Text(), "+build ") {
-			t.Errorf("filterOutBuildAnnotations failed to filter build tag")
-		}
-
-		if strings.Contains(cg.Text(), "non-tag comment") {
-			found = true
-		}
-	}
-	if !found {
-		t.Errorf("filterOutBuildAnnotations should not remove non-build tag comment")
-	}
-}