Fix use of va_list on Android.

.github/workflows/ci.yml

@@ -109,6 +109,17 @@ jobs:
           sudo apt-get install g++-multilib scons
       - name: Build
         run: ./build ndk=$ANDROID_NDK
+      - name: Enable KVM
+        run: |
+          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
+          sudo udevadm control --reload-rules
+          sudo udevadm trigger --name-match=kvm
+      - name: Test
+        uses: reactivecircus/android-emulator-runner@v2
+        with:
+          arch: x86_64
+          api-level: 28
+          script: ./.github/workflows/test-android-x64
   web:
     runs-on: ubuntu-latest
     steps:

.github/workflows/test-android-x64

@@ -0,0 +1,13 @@
+#!/bin/bash -ex
+adb push out/snapshots/HelloApp.vfuel /data/local/tmp
+adb push out/snapshots/TestRunner.vfuel /data/local/tmp
+adb push out/snapshots/BenchmarkRunner.vfuel /data/local/tmp
+
+adb push out/DebugAndroidX64/primordialsoup /data/local/tmp
+adb shell /data/local/tmp/primordialsoup /data/local/tmp/HelloApp.vfuel
+adb shell /data/local/tmp/primordialsoup /data/local/tmp/TestRunner.vfuel
+
+adb push out/ReleaseAndroidX64/primordialsoup /data/local/tmp
+adb shell /data/local/tmp/primordialsoup /data/local/tmp/HelloApp.vfuel
+adb shell /data/local/tmp/primordialsoup /data/local/tmp/TestRunner.vfuel
+adb shell /data/local/tmp/primordialsoup /data/local/tmp/BenchmarkRunner.vfuel

vm/os_android.cc

@@ -63,25 +63,28 @@ intptr_t OS::NumberOfAvailableProcessors() {
   return sysconf(_SC_NPROCESSORS_ONLN);
 }
 
-static void VFPrint(FILE* stream, const char* format, va_list args) {
-  vfprintf(stream, format, args);
-  fflush(stream);
-}
-
 void OS::Print(const char* format, ...) {
   va_list args;
+
+  va_start(args, format);
+  vfprintf(stdout, format, args);
+  fflush(stdout);
+  va_end(args);
+
   va_start(args, format);
-  VFPrint(stdout, format, args);
-  // Forward to the Android log for remote access.
   __android_log_vprint(ANDROID_LOG_INFO, "PrimordialSoup", format, args);
   va_end(args);
 }
 
 void OS::PrintErr(const char* format, ...) {
   va_list args;
+
+  va_start(args, format);
+  vfprintf(stderr, format, args);
+  fflush(stderr);
+  va_end(args);
+
   va_start(args, format);
-  VFPrint(stderr, format, args);
-  // Forward to the Android log for remote access.
   __android_log_vprint(ANDROID_LOG_ERROR, "PrimordialSoup", format, args);
   va_end(args);
 }