From 3f95c6634578c08ac4fc93560638031f114d076b Mon Sep 17 00:00:00 2001
From: Alan Donovan <adonovan@google.com>
Date: Sat, 20 Feb 2016 19:34:40 -0500
Subject: [PATCH] cmd/guru: allow foo/... and -foo patterns in scope argument

Also, document -scope argument.

Depends on CL 19746 (buildutil.ExpandPatterns)

Change-Id: I3c9000e94d87cca5c2c49fe8de12a77fc43f7257
Reviewed-on: https://go-review.googlesource.com/19747
Reviewed-by: Daniel Morsing <daniel.morsing@gmail.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
---
 cmd/guru/guru.go | 16 ++++++----------
 cmd/guru/main.go | 12 ++++++++++--
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/cmd/guru/guru.go b/cmd/guru/guru.go
index 960b061934..7b25884999 100644
--- a/cmd/guru/guru.go
+++ b/cmd/guru/guru.go
@@ -22,6 +22,7 @@ import (
 
 	"golang.org/x/tools/cmd/guru/serial"
 	"golang.org/x/tools/go/ast/astutil"
+	"golang.org/x/tools/go/buildutil"
 	"golang.org/x/tools/go/loader"
 	"golang.org/x/tools/go/pointer"
 	"golang.org/x/tools/go/ssa"
@@ -129,18 +130,13 @@ func Run(q *Query) error {
 }
 
 func setPTAScope(lconf *loader.Config, scope []string) error {
-	if len(scope) == 0 {
+	pkgs := buildutil.ExpandPatterns(lconf.Build, scope)
+	if len(pkgs) == 0 {
 		return fmt.Errorf("no packages specified for pointer analysis scope")
 	}
-
-	// Determine initial packages for PTA.
-	args, err := lconf.FromArgs(scope, true)
-	if err != nil {
-		return err
-	}
-	if len(args) > 0 {
-		return fmt.Errorf("surplus arguments: %q", args)
-	}
+	// The value of each entry in pkgs is true,
+	// giving ImportWithTests (not Import) semantics.
+	lconf.ImportPkgs = pkgs
 	return nil
 }
 
diff --git a/cmd/guru/main.go b/cmd/guru/main.go
index 538bcd5bbc..97d7acacb0 100644
--- a/cmd/guru/main.go
+++ b/cmd/guru/main.go
@@ -34,7 +34,7 @@ import (
 // flags
 var (
 	modifiedFlag   = flag.Bool("modified", false, "read archive of modified files from standard input")
-	scopeFlag      = flag.String("scope", "", "comma-separated list of `packages` the analysis should be limited to (default=all)")
+	scopeFlag      = flag.String("scope", "", "comma-separated list of `packages` the analysis should be limited to")
 	ptalogFlag     = flag.String("ptalog", "", "write points-to analysis log to `file`")
 	formatFlag     = flag.String("format", "plain", "output `format`; one of {plain,json,xml}")
 	reflectFlag    = flag.Bool("reflect", false, "analyze reflection soundly (slow)")
@@ -78,13 +78,21 @@ The -format flag controls the output format:
 	xml	structured data in XML syntax.
 
 The -modified flag causes guru to read an archive from standard input.
-
 	Files in this archive will be used in preference to those in
 	the file system.  In this way, a text editor may supply guru
 	with the contents of its unsaved buffers.  Each archive entry
 	consists of the file name, a newline, the decimal file size,
 	another newline, and the contents of the file.
 
+The -scope flag restricts analysis to the specified packages.
+	Its value is a comma-separated list of patterns of these forms:
+		golang.org/x/tools/cmd/guru     # a single package
+		golang.org/x/tools/...          # all packages beneath dir
+		...                             # the entire workspace.
+	A pattern preceded by '-' is negative, so the scope
+		encoding/...,-encoding/xml
+	matches all encoding packages except encoding/xml:
+
 User manual: http://golang.org/s/oracle-user-manual
 
 Example: describe syntax at offset 530 in this file (an import spec):