go/analysis/passes: add doc and copyright comments

...and other trivial cleanups.

Multi-line doc comments have been moved to exported Doc constants for
the sake of godoc.

Change-Id: Ib1cbec5806c699d51283c34685c4cd96953f5384
Reviewed-on: https://go-review.googlesource.com/c/142360
Reviewed-by: Michael Matloob <matloob@golang.org>

go/analysis/multichecker/multichecker.go

@@ -15,8 +15,23 @@ import (
 	"golang.org/x/tools/go/analysis/internal/checker"
 )
 
+// TODO(adonovan): support tri-state enable flags so -printf.enable=true means
+// "run only printf" and -printf.enable=false means "run all but printf"
+
+// TODO(adonovan): document (and verify) the exit codes:
+// "Vet's exit code is 2 for erroneous invocation of the tool, 1 if a
+// problem was reported, and 0 otherwise. Note that the tool does not
+// check every possible problem and depends on unreliable heuristics
+// so it should be used as guidance only, not as a firm indicator of
+// program correctness."
+
 const usage = `Analyze is a tool for static analysis of Go programs.
 
+Analyze examines Go source code and reports suspicious constructs, such as Printf
+calls whose arguments do not align with the format string. It uses heuristics
+that do not guarantee all reports are genuine problems, but it can find errors
+not caught by the compilers.
+
 Usage: analyze [-flag] [package]
 `
 

go/analysis/passes/asmdecl/asmdecl.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package asmdecl defines an Analyzer that reports mismatches between
+// assembly files and Go declarations.
 package asmdecl
 
 import (

go/analysis/passes/asmdecl/asmdecl_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package asmdecl_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/asmdecl"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, asmdecl.Analyzer, "a")
 }

go/analysis/passes/assign/assign.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package assign defines an Analyzer that detects useless assignments.
 package assign
 
 // TODO(adonovan): check also for assignments to struct fields inside
@@ -18,13 +19,15 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "assign",
-	Doc: `check for useless assignments
+const Doc = `check for useless assignments
 
 This checker reports assignments of the form x = x or a[i] = a[i].
 These are almost always useless, and even when they aren't they are
-usually a mistake.`,
+usually a mistake.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:     "assign",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }

go/analysis/passes/assign/assign_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package assign_test
 
 import (

go/analysis/passes/atomic/atomic.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package atomic defines an Analyzer that checks for common mistakes
+// using the sync/atomic package.
 package atomic
 
 import (
@@ -15,15 +17,17 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "atomic",
-	Doc: `check for common mistakes using the sync/atomic package
+const Doc = `check for common mistakes using the sync/atomic package
 
 The atomic checker looks for assignment statements of the form:
 
 	x = atomic.AddUint64(&x, 1)
 
-which are not atomic.`,
+which are not atomic.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:             "atomic",
+	Doc:              Doc,
 	Requires:         []*analysis.Analyzer{inspect.Analyzer},
 	RunDespiteErrors: true,
 	Run:              run,

go/analysis/passes/atomic/atomic_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package atomic_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/atomic"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, atomic.Analyzer, "a")
 }

go/analysis/passes/bools/bools.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package bools defines an Analyzer that detects common mistakes
+// involving boolean operators.
 package bools
 
 import (

go/analysis/passes/bools/bools_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package bools_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/bools"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, bools.Analyzer, "a")
 }

go/analysis/passes/buildtag/buildtag.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package buildtag defines an Analyzer that checks build tags.
 package buildtag
 
 import (

go/analysis/passes/buildtag/buildtag_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package buildtag_test
 
 import (
@@ -9,6 +13,5 @@ import (
 
 func Test(t *testing.T) {
 	testdata := analysistest.TestData()
-	// loads testdata/src/a/a.go
 	analysistest.Run(t, testdata, buildtag.Analyzer, "a")
 }

go/analysis/passes/cgocall/cgocall.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package cgocall defines an Analyzer that detects some violations of
+// the cgo pointer passing rules.
 package cgocall
 
 import (
@@ -18,16 +20,18 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "cgocall",
-	Doc: `detect some violations of the cgo pointer passing rules
+const Doc = `detect some violations of the cgo pointer passing rules
 
 Check for invalid cgo pointer passing.
 This looks for code that uses cgo to call C code passing values
 whose types are almost always invalid according to the cgo pointer
 sharing rules.
 Specifically, it warns about attempts to pass a Go chan, map, func,
-or slice to C, either directly, or via a pointer, array, or struct.`,
+or slice to C, either directly, or via a pointer, array, or struct.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:             "cgocall",
+	Doc:              Doc,
 	Requires:         []*analysis.Analyzer{inspect.Analyzer},
 	RunDespiteErrors: true,
 	Run:              run,

go/analysis/passes/cgocall/cgocall_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package cgocall_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/cgocall"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, cgocall.Analyzer, "a", "b")
 }

go/analysis/passes/composite/composite.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package composite defines an Analyzer that checks for unkeyed
+// composite literals.
 package composite
 
 import (
@@ -14,14 +16,16 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "composites",
-	Doc: `checked for unkeyed composite literals
+const Doc = `checked for unkeyed composite literals
 
 This analyzer reports a diagnostic for composite literals of struct
 types imported from another package that do not use the field-keyed
 syntax. Such literals are fragile because the addition of a new field
-(even if unexported) to the struct will cause compilation to fail.`,
+(even if unexported) to the struct will cause compilation to fail.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:             "composites",
+	Doc:              Doc,
 	Requires:         []*analysis.Analyzer{inspect.Analyzer},
 	RunDespiteErrors: true,
 	Run:              run,

go/analysis/passes/composite/composite_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package composite_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/composite"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, composite.Analyzer, "a")
 }

go/analysis/passes/copylock/copylock.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package copylock defines an Analyzer that checks for locks
+// erroneously passed by value.
 package copylock
 
 import (
@@ -17,9 +19,15 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
+const Doc = `check for locks erroneously passed by value
+
+Inadvertently copying a value containing a lock, such as sync.Mutex or
+sync.WaitGroup, may cause both copies to malfunction. Generally such
+values should be referred to through a pointer.`
+
 var Analyzer = &analysis.Analyzer{
 	Name:             "copylocks",
-	Doc:              "check for locks erroneously passed by value",
+	Doc:              Doc,
 	Requires:         []*analysis.Analyzer{inspect.Analyzer},
 	RunDespiteErrors: true,
 	Run:              run,

go/analysis/passes/copylock/copylock_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package copylock_test
 
 import (

go/analysis/passes/ctrlflow/ctrlflow_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package ctrlflow_test
 
 import (

go/analysis/passes/findcall/findcall.go

@@ -1,6 +1,11 @@
-// The findcall package is a trivial example and test of an analyzer of
-// Go source code. It reports a diagnostic for every call to a function or
-// method of the name specified by its --name flag.
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The findcall package defines an Analyzer that serves as a trivial
+// example and test of the Analysis API. It reports a diagnostic for
+// every call to a function or method of the name specified by its
+// -name flag.
 package findcall
 
 import (
@@ -10,13 +15,15 @@ import (
 	"golang.org/x/tools/go/analysis"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "findcall",
-	Doc: `find calls to a particular function
+const Doc = `find calls to a particular function
 
 The findcall analysis reports calls to functions or methods
-of a particular name.`,
-	Run:              findcall,
+of a particular name.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:             "findcall",
+	Doc:              Doc,
+	Run:              run,
 	RunDespiteErrors: true,
 	FactTypes:        []analysis.Fact{new(foundFact)},
 }
@@ -27,7 +34,7 @@ func init() {
 	Analyzer.Flags.StringVar(&name, "name", name, "name of the function to find")
 }
 
-func findcall(pass *analysis.Pass) (interface{}, error) {
+func run(pass *analysis.Pass) (interface{}, error) {
 	for _, f := range pass.Files {
 		ast.Inspect(f, func(n ast.Node) bool {
 			if call, ok := n.(*ast.CallExpr); ok {

go/analysis/passes/findcall/findcall_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package findcall_test
 
 import (

go/analysis/passes/inspect/inspect.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package inspect is an analysis that provides an AST inspector
+// Package inspect defines an Analyzer that provides an AST inspector
 // (golang.org/x/tools/go/ast/inspect.Inspect) for the syntax trees of a
 // package. It is only a building block for other analyzers.
 //

go/analysis/passes/loopclosure/loopclosure.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package loopclosure defines an Analyzer that checks for references to
+// enclosing loop variables from within nested functions.
 package loopclosure
 
 import (
@@ -22,9 +24,7 @@ import (
 //		}()
 //	}
 
-var Analyzer = &analysis.Analyzer{
-	Name: "loopclosure",
-	Doc: `check references to loop variables from within nested functions
+const Doc = `check references to loop variables from within nested functions
 
 This analyzer checks for references to loop variables from within a
 function literal inside the loop body. It checks only instances where
@@ -40,7 +40,11 @@ For example:
 		}()
 	}
 
-See: https://golang.org/doc/go_faq.html#closures_and_goroutines`,
+See: https://golang.org/doc/go_faq.html#closures_and_goroutines`
+
+var Analyzer = &analysis.Analyzer{
+	Name:     "loopclosure",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }

go/analysis/passes/loopclosure/loopclosure_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package loopclosure_test
 
 import (

go/analysis/passes/lostcancel/lostcancel.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package lostcancel defines an Analyzer that checks for failure to
+// call a context cancelation function.
 package lostcancel
 
 import (
@@ -16,7 +18,7 @@ import (
 	"golang.org/x/tools/go/cfg"
 )
 
-const doc = `check cancel func returned by context.WithCancel is called
+const Doc = `check cancel func returned by context.WithCancel is called
 
 The cancelation function returned by context.WithCancel, WithTimeout,
 and WithDeadline must be called or the new context will remain live
@@ -25,7 +27,7 @@ until its parent context is cancelled.
 
 var Analyzer = &analysis.Analyzer{
 	Name: "lostcancel",
-	Doc:  doc,
+	Doc:  Doc,
 	Run:  run,
 	Requires: []*analysis.Analyzer{
 		inspect.Analyzer,

go/analysis/passes/lostcancel/lostcancel_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package lostcancel_test
 
 import (
@@ -9,5 +13,5 @@ import (
 
 func Test(t *testing.T) {
 	testdata := analysistest.TestData()
-	analysistest.Run(t, testdata, lostcancel.Analyzer, "a") // load testdata/src/a/a.go
+	analysistest.Run(t, testdata, lostcancel.Analyzer, "a")
 }

go/analysis/passes/nilfunc/nilfunc.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package nilfunc defines an Analyzer that checks for useless
+// comparisons against nil.
 package nilfunc
 
 import (
@@ -14,11 +16,13 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "nilfunc",
-	Doc: `check for useless comparisons between functions and nil
+const Doc = `check for useless comparisons between functions and nil
 
-A useless comparison is one like f == nil as opposed to f() == nil.`,
+A useless comparison is one like f == nil as opposed to f() == nil.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:     "nilfunc",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }

go/analysis/passes/nilfunc/nilfunc_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package nilfunc_test
 
 import (

go/analysis/passes/pkgfact/pkgfact.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 // The pkgfact package is a demonstration and test of the package fact
 // mechanism.
 //

go/analysis/passes/pkgfact/pkgfact_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package pkgfact_test
 
 import (
@@ -9,5 +13,5 @@ import (
 
 func Test(t *testing.T) {
 	testdata := analysistest.TestData()
-	analysistest.Run(t, testdata, pkgfact.Analyzer, "c") // load testdata/src/c/c.go
+	analysistest.Run(t, testdata, pkgfact.Analyzer, "c")
 }

go/analysis/passes/shift/shift.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package shift defines an Analyzer that checks for shifts that exceed
+// the width of an integer.
 package shift
 
 // TODO(adonovan): integrate with ctrflow (CFG-based) dead code analysis. May

go/analysis/passes/shift/shift_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package shift_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/shift"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, shift.Analyzer, "a")
 }

go/analysis/passes/stdmethods/stdmethods.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package stdmethods defines an Analyzer that checks for misspellings
+// in the signatures of methods similar to well-known interfaces.
 package stdmethods
 
 import (
@@ -18,9 +20,7 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "stdmethods",
-	Doc: `check signature of methods of well-known interfaces
+const Doc = `check signature of methods of well-known interfaces
 
 Sometimes a type may be intended to satisfy an interface but may fail to
 do so because of a mistake in its method signature.
@@ -39,7 +39,11 @@ Checked method names include:
 	Peek ReadByte ReadFrom ReadRune Scan Seek
 	UnmarshalJSON UnreadByte UnreadRune WriteByte
 	WriteTo
-`,
+`
+
+var Analyzer = &analysis.Analyzer{
+	Name:     "stdmethods",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }

go/analysis/passes/stdmethods/stdmethods_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package stdmethods_test
 
 import (

go/analysis/passes/structtag/structtag.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package structtag defines an Analyzer that checks struct field tags
+// are well formed.
 package structtag
 
 import (
@@ -19,11 +21,13 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "structtag",
-	Doc: `check that struct field tags conform to reflect.StructTag.Get
+const Doc = `check that struct field tags conform to reflect.StructTag.Get
 
-Also report certain struct tags (json, xml) used with unexported fields.`,
+Also report certain struct tags (json, xml) used with unexported fields.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:             "structtag",
+	Doc:              Doc,
 	Requires:         []*analysis.Analyzer{inspect.Analyzer},
 	RunDespiteErrors: true,
 	Run:              run,

go/analysis/passes/structtag/structtag_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package structtag_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/structtag"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, structtag.Analyzer, "a")
 }

go/analysis/passes/tests/tests.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package tests defines an Analyzer that checks for common mistaken
+// usages of tests and examples.
 package tests
 
 import (
@@ -14,14 +16,16 @@ import (
 	"golang.org/x/tools/go/analysis"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "tests",
-	Doc: `check for common mistaken usages of tests and examples
+const Doc = `check for common mistaken usages of tests and examples
 
 The tests checker walks Test, Benchmark and Example functions checking
 malformed names, wrong signatures and examples documenting non-existent
-identifiers.`,
-	Run: run,
+identifiers.`
+
+var Analyzer = &analysis.Analyzer{
+	Name: "tests",
+	Doc:  Doc,
+	Run:  run,
 }
 
 func run(pass *analysis.Pass) (interface{}, error) {

go/analysis/passes/tests/tests_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package tests_test
 
 import (

go/analysis/passes/unreachable/unreachable.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package unreachable defines an Analyzer that checks for unreachable code.
 package unreachable
 
 // TODO(adonovan): use the new cfg package, which is more precise.
@@ -16,13 +17,15 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
-var Analyzer = &analysis.Analyzer{
-	Name: "unreachable",
-	Doc: `check for unreachable code
+const Doc = `check for unreachable code
 
 The unreachable analyzer finds statements that execution can never reach
 because they are preceded by an return statement, a call to panic, an
-infinite loop, or similar constructs.`,
+infinite loop, or similar constructs.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:             "unreachable",
+	Doc:              Doc,
 	Requires:         []*analysis.Analyzer{inspect.Analyzer},
 	RunDespiteErrors: true,
 	Run:              run,

go/analysis/passes/unreachable/unreachable_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package unreachable_test
 
 import (

go/analysis/passes/unsafeptr/unsafeptr.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Package unsafeptr defines an Analyzer that checks for invalid
+// conversions of uintptr to unsafe.Pointer.
 package unsafeptr
 
 import (
@@ -14,9 +16,17 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
+const Doc = `check for invalid conversions of uintptr to unsafe.Pointer
+
+The unsafeptr analyzer reports likely incorrect uses of unsafe.Pointer
+to convert integers to pointers. A conversion from uintptr to
+unsafe.Pointer is invalid if it implies that there is a uintptr-typed
+word in memory that holds a pointer value, because that word will be
+invisible to stack copying and to the garbage collector.`
+
 var Analyzer = &analysis.Analyzer{
 	Name:     "unsafeptr",
-	Doc:      "check for invalid conversions of uintptr to unsafe.Pointer",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }

go/analysis/passes/unsafeptr/unsafeptr_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package unsafeptr_test
 
 import (
@@ -7,7 +11,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/unsafeptr"
 )
 
-func TestFromFileSystem(t *testing.T) {
+func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, unsafeptr.Analyzer, "a")
 }

go/analysis/passes/unusedresult/unusedresult.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package unusedresult defines an analyer that checks for unused
+// Package unusedresult defines an analyzer that checks for unused
 // results of calls to certain pure functions.
 package unusedresult
 
@@ -23,15 +23,17 @@ import (
 // fact for each function that tail-calls one of the functions that we
 // check, and check those functions too.
 
-var Analyzer = &analysis.Analyzer{
-	Name: "unusedresult",
-	Doc: `check for unused results of calls to some functions
+const Doc = `check for unused results of calls to some functions
 
 Some functions like fmt.Errorf return a result and have no side effects,
 so it is always a mistake to discard the result. This analyzer reports
 calls to certain functions in which the result of the call is ignored.
 
-The set of functions may be controlled using flags.`,
+The set of functions may be controlled using flags.`
+
+var Analyzer = &analysis.Analyzer{
+	Name:     "unusedresult",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }

go/analysis/passes/unusedresult/unusedresult_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package unusedresult_test
 
 import (