cmd/dist: refine test conditions and enable more cgo tests on Android, iOS

This CL moves many cgo test conditions out of dist and into the tests
themselves, now that they can use the testenv.Must* helpers.

This refines a lot of the conditions, which happens to have the effect
of enabling many tests on Android and iOS that are disabled by
too-coarse GOOS checks in dist today.

Fixes #15919.

Change-Id: I2947526b08928d2f7f89f107b5b2403b32092ed8
Reviewed-on: https://go-review.googlesource.com/c/go/+/495918
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/cmd/cgo/internal/testplugin/plugin_test.go b/src/cmd/cgo/internal/testplugin/plugin_test.go
index 84ea839a2f..e211a96304 100644
--- a/src/cmd/cgo/internal/testplugin/plugin_test.go
+++ b/src/cmd/cgo/internal/testplugin/plugin_test.go
@@ -9,10 +9,13 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"internal/platform"
+	"internal/testenv"
 	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
 	"testing"
 	"time"
@@ -44,6 +47,17 @@ func prettyPrintf(format string, args ...interface{}) {
 }
 
 func testMain(m *testing.M) int {
+	// TODO: Move all of this initialization stuff into a sync.Once that each
+	// test can use, where we can properly t.Skip.
+	if !platform.BuildModeSupported(runtime.Compiler, "plugin", runtime.GOOS, runtime.GOARCH) {
+		fmt.Printf("SKIP - plugin build mode not supported\n")
+		os.Exit(0)
+	}
+	if !testenv.HasCGO() {
+		fmt.Printf("SKIP - cgo not supported\n")
+		os.Exit(0)
+	}
+
 	cwd, err := os.Getwd()
 	if err != nil {
 		log.Fatal(err)