test: compile source files as if from "test" module

This CL updates test/run.go to compile xxx.dir/x.go with a package
path of "test/x" instead of just "x". This prevents collisions with
standard library packages.

It also requires updating a handful of tests to account for the
updated package paths.

Fixes #25693.

Change-Id: I49208c56ab3cb229ed667d547cd6e004d2175fcf
Reviewed-on: https://go-review.googlesource.com/c/go/+/395258
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

test/fixedbugs/bug345.go

@@ -1,10 +1,7 @@
-// +build !windows
-// errorcheckdir -n
+// errorcheckdir
 
 // Copyright 2011 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 ignored
-
-// TODO(ysmolsky): Fix golang.org/issue/25693 to enable on Windows.

test/fixedbugs/issue19467.dir/z.go

@@ -5,9 +5,10 @@
 package main
 
 import (
-	"./mysync"
 	"log"
 	"runtime"
+
+	"./mysync"
 )
 
 func main() {
@@ -23,8 +24,8 @@ func main() {
 		}
 	}
 	expecting := []string{
-		"mysync.(*WaitGroup).Add",
-		"mysync.(*WaitGroup).Done",
+		"test/mysync.(*WaitGroup).Add",
+		"test/mysync.(*WaitGroup).Done",
 	}
 	for i := 0; i < 2; i++ {
 		if frames[i].Function != expecting[i] {

test/fixedbugs/issue29919.dir/a.go

@@ -51,14 +51,14 @@ func f() int {
 	}
 	iter := runtime.CallersFrames(pcs[:n])
 	f, more := iter.Next()
-	if f.Function != "a.f" || !strings.HasSuffix(f.File, "a.go") || f.Line != 22 {
+	if f.Function != "test/a.f" || !strings.HasSuffix(f.File, "a.go") || f.Line != 22 {
 		panic(fmt.Sprintf("bad f %v\n", f))
 	}
 	if !more {
 		panic("traceback truncated after f")
 	}
 	f, more = iter.Next()
-	if f.Function != "a.init" || !strings.HasSuffix(f.File, "a.go") || f.Line != 15 {
+	if f.Function != "test/a.init" || !strings.HasSuffix(f.File, "a.go") || f.Line != 15 {
 		panic(fmt.Sprintf("bad init %v\n", f))
 	}
 	if !more {

test/fixedbugs/issue42401.dir/b.go

@@ -5,11 +5,12 @@
 package main
 
 import (
-	"./a"
 	_ "unsafe"
+
+	"./a"
 )
 
-//go:linkname s a.s
+//go:linkname s test/a.s
 var s string
 
 func main() {

test/fixedbugs/issue5957.dir/c.go

@@ -1,9 +1,9 @@
 package p
 
 import (
-	"./a" // ERROR "imported and not used: \x22a\x22 as surprise|imported and not used: surprise"
-	"./b" // ERROR "imported and not used: \x22b\x22 as surprise2|imported and not used: surprise2"
-	b "./b" // ERROR "imported and not used: \x22b\x22$|imported and not used: surprise2"
+	"./a" // ERROR "imported and not used: \x22test/a\x22 as surprise|imported and not used: surprise"
+	"./b" // ERROR "imported and not used: \x22test/b\x22 as surprise2|imported and not used: surprise2"
+	b "./b" // ERROR "imported and not used: \x22test/b\x22$|imported and not used: surprise2"
 	foo "math" // ERROR "imported and not used: \x22math\x22 as foo|imported and not used: math"
 	"fmt" // actually used
 	"strings" // ERROR "imported and not used: \x22strings\x22|imported and not used: strings"

test/linkname.dir/linkname2.go

@@ -2,7 +2,7 @@ package y
 
 import _ "unsafe"
 
-//go:linkname byteIndex linkname1.indexByte
+//go:linkname byteIndex test/linkname1.indexByte
 func byteIndex(xs []byte, b byte) int // ERROR "leaking param: xs"
 
 func ContainsSlash(data []byte) bool { // ERROR "leaking param: data" "can inline ContainsSlash"

test/run.go

@@ -263,14 +263,13 @@ func compileFile(runcmd runCmd, longname string, flags []string) (out []byte, er
 	return runcmd(cmd...)
 }
 
-func compileInDir(runcmd runCmd, dir string, flags []string, localImports bool, pkgname string, names ...string) (out []byte, err error) {
-	if pkgname != "main" {
-		pkgname = strings.TrimSuffix(names[0], ".go")
-	}
-	cmd := []string{goTool(), "tool", "compile", "-e", "-p=" + pkgname}
-	if localImports {
-		// Set relative path for local imports and import search path to current dir.
-		cmd = append(cmd, "-D", ".", "-I", ".")
+func compileInDir(runcmd runCmd, dir string, flags []string, pkgname string, names ...string) (out []byte, err error) {
+	cmd := []string{goTool(), "tool", "compile", "-e", "-D", "test", "-I", "."}
+	if pkgname == "main" {
+		cmd = append(cmd, "-p=main")
+	} else {
+		pkgname = path.Join("test", strings.TrimSuffix(names[0], ".go"))
+		cmd = append(cmd, "-o", pkgname+".a", "-p", pkgname)
 	}
 	cmd = append(cmd, flags...)
 	if *linkshared {
@@ -615,7 +614,6 @@ func (t *test) run() {
 	wantError := false
 	wantAuto := false
 	singlefilepkgs := false
-	localImports := true
 	f, err := splitQuoted(action)
 	if err != nil {
 		t.err = fmt.Errorf("invalid test recipe: %v", err)
@@ -659,12 +657,6 @@ func (t *test) run() {
 			wantError = false
 		case "-s":
 			singlefilepkgs = true
-		case "-n":
-			// Do not set relative path for local imports to current dir,
-			// e.g. do not pass -D . -I . to the compiler.
-			// Used in fixedbugs/bug345.go to allow compilation and import of local pkg.
-			// See golang.org/issue/25635
-			localImports = false
 		case "-t": // timeout in seconds
 			args = args[1:]
 			var err error
@@ -886,7 +878,7 @@ func (t *test) run() {
 			return
 		}
 		for _, pkg := range pkgs {
-			_, t.err = compileInDir(runcmd, longdir, flags, localImports, pkg.name, pkg.files...)
+			_, t.err = compileInDir(runcmd, longdir, flags, pkg.name, pkg.files...)
 			if t.err != nil {
 				return
 			}
@@ -910,7 +902,7 @@ func (t *test) run() {
 			errPkg--
 		}
 		for i, pkg := range pkgs {
-			out, err := compileInDir(runcmd, longdir, flags, localImports, pkg.name, pkg.files...)
+			out, err := compileInDir(runcmd, longdir, flags, pkg.name, pkg.files...)
 			if i == errPkg {
 				if wantError && err == nil {
 					t.err = fmt.Errorf("compilation succeeded unexpectedly\n%s", out)
@@ -959,7 +951,7 @@ func (t *test) run() {
 		}
 
 		for i, pkg := range pkgs {
-			_, err := compileInDir(runcmd, longdir, flags, localImports, pkg.name, pkg.files...)
+			_, err := compileInDir(runcmd, longdir, flags, pkg.name, pkg.files...)
 			// Allow this package compilation fail based on conditions below;
 			// its errors were checked in previous case.
 			if err != nil && !(wantError && action == "errorcheckandrundir" && i == len(pkgs)-2) {
@@ -1283,6 +1275,10 @@ func (t *test) makeTempDir() {
 	if *keep {
 		log.Printf("Temporary directory is %s", t.tempDir)
 	}
+	err = os.Mkdir(filepath.Join(t.tempDir, "test"), 0o755)
+	if err != nil {
+		log.Fatal(err)
+	}
 }
 
 // checkExpectedOutput compares the output from compiling and/or running with the contents