internal/testenv: exclude GOMAXPROCS when building test programfix-runtime-test-GOMAXPROCS

In the environment where GOMAXPROCS set explicitly, for example to 3 in
shell profile, the runtime tests will fail with the following error,

----
ok      regexp/syntax   0.428s
--- FAIL: TestCgroupGOMAXPROCS (0.81s)
    crash_test.go:186: running /home/ms/src/go/bin/go build -o /tmp/go-build1753772192/testprog.exe
    crash_test.go:208: built testprog in 796.664277ms
    --- FAIL: TestCgroupGOMAXPROCS/containermaxprocs=0 (0.00s)
        cgroup_linux_test.go:60: /tmp/go-build1753772192/testprog.exe PrintGOMAXPROCS (907.06µs): ok
        cgroup_linux_test.go:63: output got "3\n" want "4\n"
--- FAIL: TestCgroupGOMAXPROCSNoLimit (0.00s)
    cgroup_linux_test.go:82: /tmp/go-build1753772192/testprog.exe PrintGOMAXPROCS (879.194µs): ok
    cgroup_linux_test.go:85: output got "3\n" want "4\n"
--- FAIL: TestCgroupGOMAXPROCSHigherThanNumCPU (0.00s)
    cgroup_linux_test.go:102: /tmp/go-build1753772192/testprog.exe PrintGOMAXPROCS (852.396µs): ok
    cgroup_linux_test.go:105: output got "3\n" want "4\n"
--- FAIL: TestCgroupGOMAXPROCSRound (0.01s)
    --- FAIL: TestCgroupGOMAXPROCSRound/50000 (0.00s)
        cgroup_linux_test.go:156: /tmp/go-build1753772192/testprog.exe PrintGOMAXPROCS (852.099µs): ok
        cgroup_linux_test.go:159: output got "3\n" want "2\n"
    --- FAIL: TestCgroupGOMAXPROCSRound/100000 (0.00s)
        cgroup_linux_test.go:156: /tmp/go-build1753772192/testprog.exe PrintGOMAXPROCS (894.001µs): ok
        cgroup_linux_test.go:159: output got "3\n" want "2\n"
    --- FAIL: TestCgroupGOMAXPROCSRound/150000 (0.00s)
        cgroup_linux_test.go:156: /tmp/go-build1753772192/testprog.exe PrintGOMAXPROCS (850.897µs): ok
        cgroup_linux_test.go:159: output got "3\n" want "2\n"
--- FAIL: TestCgroupGOMAXPROCSSchedAffinity (0.00s)
    cgroup_linux_test.go:229: /tmp/go-build1753772192/testprog.exe PrintGOMAXPROCS (867.987µs): ok
    cgroup_linux_test.go:232: output got "3\n" want "2\n"
FAIL
FAIL    runtime 23.088s
----

This changes exclude the GOMAXPROCS when building program for testing so it
does not affect the tests.

Change-Id: I590d9eca57026539413cf4c93b37f624f179d534

6 files changed, 11 insertions, 9 deletions

diff --git a/src/internal/cgrouptest/cgrouptest_linux.go b/src/internal/cgrouptest/cgrouptest_linux.go
index f23c37a705..8437f992f7 100644
--- a/src/internal/cgrouptest/cgrouptest_linux.go
+++ b/src/internal/cgrouptest/cgrouptest_linux.go
@@ -114,7 +114,7 @@ func findCurrent(t *testing.T) (string, string) {
 	if ver != cgroup.V2 {
 		t.Skipf("cgroup: running on cgroup v%d want v2", ver)
 	}
-	rel := string(buf[1:n]) // The returned path always starts with /, skip it.
+	rel := string(buf[1:n])       // The returned path always starts with /, skip it.
 	rel = filepath.Join(".", rel) // Make sure this isn't empty string at root.
 	return mount, rel
 }
diff --git a/src/internal/runtime/strconv/atoi.go b/src/internal/runtime/strconv/atoi.go
index 87b3faf6d5..0308757c6f 100644
--- a/src/internal/runtime/strconv/atoi.go
+++ b/src/internal/runtime/strconv/atoi.go
@@ -73,4 +73,3 @@ func Atoi32(s string) (int32, bool) {
 	}
 	return 0, false
 }
-
diff --git a/src/internal/runtime/strconv/atoi_test.go b/src/internal/runtime/strconv/atoi_test.go
index 49cd6f160a..71a8030b1d 100644
--- a/src/internal/runtime/strconv/atoi_test.go
+++ b/src/internal/runtime/strconv/atoi_test.go
@@ -102,4 +102,3 @@ func TestAtoi32(t *testing.T) {
 		}
 	}
 }
-
diff --git a/src/internal/testenv/exec.go b/src/internal/testenv/exec.go
index 7b251b6022..1ad77fe21a 100644
--- a/src/internal/testenv/exec.go
+++ b/src/internal/testenv/exec.go
@@ -137,6 +137,10 @@ func CleanCmdEnv(cmd *exec.Cmd) *exec.Cmd {
 		if strings.HasPrefix(env, "GOTRACEBACK=") {
 			continue
 		}
+		// Exclude for TestCgroupGOMAXPROCSXxx.
+		if strings.HasPrefix(env, "GOMAXPROCS=") {
+			continue
+		}
 		cmd.Env = append(cmd.Env, env)
 	}
 	return cmd
diff --git a/src/runtime/debug.go b/src/runtime/debug.go
index 206cf39f02..dacadd2721 100644
--- a/src/runtime/debug.go
+++ b/src/runtime/debug.go
@@ -19,10 +19,10 @@ import (
 // GOMAXPROCS defaults to that value.
 //
 // Otherwise, the Go runtime selects an appropriate default value from a combination of
-//  - the number of logical CPUs on the machine,
-//  - the process’s CPU affinity mask,
-//  - and, on Linux, the process’s average CPU throughput limit based on cgroup CPU
-//    quota, if any.
+//   - the number of logical CPUs on the machine,
+//   - the process’s CPU affinity mask,
+//   - and, on Linux, the process’s average CPU throughput limit based on cgroup CPU
+//     quota, if any.
 //
 // If GODEBUG=containermaxprocs=0 is set and GOMAXPROCS is not set by the
 // environment variable, then GOMAXPROCS instead defaults to the value of
diff --git a/src/unicode/utf8/utf8.go b/src/unicode/utf8/utf8.go
index 82fa7c0d4d..3be2f15e8a 100644
--- a/src/unicode/utf8/utf8.go
+++ b/src/unicode/utf8/utf8.go
@@ -263,7 +263,7 @@ func DecodeLastRune(p []byte) (r rune, size int) {
 	// guard against O(n^2) behavior when traversing
 	// backwards through strings with long sequences of
 	// invalid UTF-8.
-	lim := max(end - UTFMax, 0)
+	lim := max(end-UTFMax, 0)
 	for start--; start >= lim; start-- {
 		if RuneStart(p[start]) {
 			break
@@ -300,7 +300,7 @@ func DecodeLastRuneInString(s string) (r rune, size int) {
 	// guard against O(n^2) behavior when traversing
 	// backwards through strings with long sequences of
 	// invalid UTF-8.
-	lim := max(end - UTFMax, 0)
+	lim := max(end-UTFMax, 0)
 	for start--; start >= lim; start-- {
 		if RuneStart(s[start]) {
 			break