riscv: run tests in QEMU

These tests should make sure that things that work now won't break in
the future.

Author: aykevl

.circleci/config.yml

@@ -246,7 +246,9 @@ commands:
             llvm-build
       - run:
           name: "Test TinyGo"
-          command: make test
+          command: |
+            make gen-device-sifive # needed for testing
+            make test
       - run:
           name: "Build TinyGo release"
           command: |

azure-pipelines.yml

@@ -52,6 +52,7 @@ jobs:
         script: |
           export PATH="/c/Go1.13/bin:$PATH:./llvm-build/bin:/c/Program Files/qemu"
           unset GOROOT
+          make gen-device-sifive # needed for testing
           make test
     - task: Bash@3
       displayName: Build TinyGo release tarball

main_test.go

@@ -55,6 +55,12 @@ func TestCompiler(t *testing.T) {
 		runPlatTests("cortex-m-qemu", matches, t)
 	})
 
+	if runtime.GOOS != "linux" {
+		t.Run("EmulatedHiFive1", func(t *testing.T) {
+			runPlatTests("hifive1-qemu", matches, t)
+		})
+	}
+
 	if runtime.GOOS == "linux" {
 		t.Run("ARMLinux", func(t *testing.T) {
 			runPlatTests("arm--linux-gnueabihf", matches, t)
@@ -83,6 +89,11 @@ func runPlatTests(target string, matches []string, t *testing.T) {
 			// run all tests on host
 		case target == "cortex-m-qemu":
 			// all tests are supported
+		case target == "hifive1-qemu":
+			if path == filepath.Join("testdata", "cgo")+string(filepath.Separator) {
+				// CGo doesn't work yet for some reason.
+				continue
+			}
 		default:
 			// cross-compilation of cgo is not yet supported
 			if path == filepath.Join("testdata", "cgo")+string(filepath.Separator) {
@@ -203,7 +214,11 @@ func runTest(path, target string, t *testing.T) {
 	}
 	close(runComplete)
 
-	if ranTooLong {
+	if ranTooLong && target != "hifive1-qemu" {
+		// Note: the hifive1-qemu exception is here because QEMU does
+		// not yet include the SiFive test finisher used to exit tests.
+		// https://github.com/sifive/riscv-qemu/commit/0eec372a36b7237caf16ec7c7646a202faba5fdb
+		// It's a crude hack, but it makes RISC-V testable.
 		stdout.WriteString("--- test ran too long, terminating...\n")
 	}
 

src/runtime/runtime_fe310_qemu.go

@@ -15,6 +15,14 @@ var timestamp timeUnit
 func abort() {
 	// Signal a successful exit.
 	testExit.Set(0x5555)
+
+	// Note: the SiFive test finisher does not seem to be implemented in QEMU
+	// 4.2 (but is included in the SiFive build of QEMU). And while the above
+	// write somehow results in exiting the process on Windows, that's not the
+	// case on macOS. Therefore, make sure to halt the process with an endless
+	// loop.
+	for {
+	}
 }
 
 func ticks() timeUnit {