[vm] Support building Android target on Mac M1 arm64

[dcharkes]

Trying to build for Android on a Mac arm64 M1 fails:

dacoharkes-macbookpro2:sdk dacoharkes$ tools/build.py --os=android -aarm create_platform_sdk
ERROR at //build/config/android/config.gni:30:5: Assertion failed.
    assert(false, "Need Android toolchain support for your build CPU arch.")
    ^-----
Need Android toolchain support for your build CPU arch.

sdk/build/config/android/config.gni

Lines 27 to 31 in 30f0e0f

	if (host_cpu == "x64" || host_cpu == "x86") {
	android_host_arch = "x86_64"
	} else {
	assert(false, "Need Android toolchain support for your build CPU arch.")
	}

If we add the architecture there

  if (host_cpu == "x64" || host_cpu == "x86") {
    android_host_arch = "x86_64"
  } else if (host_cpu == "arm64") {
    android_host_arch = "arm64"
  } else {
    assert(false, "Need Android toolchain support for your build CPU arch.")
  }

then the build does not know how to build files

ninja -C xcodebuild/DebugAndroidARM -j1000 -l64 create_platform_sdk
ninja: Entering directory `xcodebuild/DebugAndroidARM'
ninja: error: '../../third_party/android_tools/ndk/sources/android/cpufeatures/cpu-features.c', needed by 'obj/third_party/android_tools/ndk/sources/android/cpufeatures/cpu_features.cpu-features.o', missing and no known rule to make it
ninja -C xcodebuild/DebugAndroidARM -j1000 -l64 create_platform_sdk done.

(Note: adding those two lines does make tools/generate_idefiles.py -aarm64 succeed.)

[a-siva]

Can this be closed ?

[dcharkes]

The build now mostly succeeds locally for JIT and AOT.

tools/build.py --os=android -aarm,arm64 runtime dart_precompiled_runtime

== ARM64 Mac

./tools/build.py --os=android --arch=x64,x64c,arm64,arm64c,arm_x64 runtime
Okay
./tools/build.py --arch=x64,x64c,arm64,arm64c runtime
Okay

./tools/build.py --arch=ia32 runtime
Exception: Failed to find a C host architecture for ia32. Need one of ['x86'] but only ['arm64', 'x64'] are available.
./tools/build.py --arch=simarm runtime
Exception: Failed to find a C target architecture for simarm. Need one of ['arm', 'riscv32', 'x86'] but only ['arm64', 'x64'] are available.
./tools/build.py --arch=simriscv32 runtime
Exception: Failed to find a C target architecture for simriscv32. Need one of ['arm', 'riscv32', 'x86'] but only ['arm64', 'x64'] are available.

== ARM64 Linux

./tools/build.py --os=android,fuchsia ...
Missing toolchain
./tools/build.py --arch=arm,arm64,simriscv64 runtime
Okay
./tools/build.py --arch=x64 runtime
Exception: Failed to find a C host architecture for x64. Need one of ['x64'] but only ['arm64'] are available.
./tools/build.py --arch=ia32 runtime
Exception: Failed to find a C host architecture for ia32. Need one of ['x86'] but only ['arm64'] are available.


== X64 Linux

./tools/build.py --os=android --arch=ia32,x64,x64c,arm,arm64,arm64c runtime
Okay
./tools/build.py --os=fuchsia --arch=x64,x64c,arm64,arm64c runtime
Okay
./tools/build.py --arch=ia32,x64,x64c,arm,arm64,arm64c,simarm,simarm64,simarm64c,simriscv32,simriscv64 runtime
Okay
./tools/build.py --arch=riscv64 --no-clang --no-goma runtime
Okay
./tools/build.py --arch=riscv32 --no-clang --no-goma runtime
Missing toolchain

from @rmacnak-google in https://dart-review.googlesource.com/c/sdk/+/241102

create_platform_sdk doesn't work yet:

$ tools/build.py --os=android -aarm create_platform_sdk
[...]
xcodebuild/DebugAndroidARM/clang_arm64/dart
[...]
output: ../../runtime/vm/object.h: 1060: error: expected "target_value" = 28, actual "host_value" = 24
version=2.18.0-edge.37eff8b8bcd124cec3534157b7c397097e112a3c (be) (Thu May 12 22:59:15 2022 +0000) on "macos_arm"
pid=69542, thread=259, isolate_group=vm-isolate(0x155813400), isolate=vm-isolate(0x155817600)
isolate_instructions=102487860, vm_instructions=102487860
  pc 0x00000001027ecb70 fp 0x000000016da06530 dart::Profiler::DumpStackTrace(void*)+0x68
  pc 0x00000001024879e4 fp 0x000000016da06550 dart::Assert::Fail(char const*, ...) const+0x28
  pc 0x000000010089c314 fp 0x000000016f8725b0 dart::Object::InVMIsolateHeap() const+0x0
  pc 0x0000000100880bd4 fp 0x000000016f872650 dart::Object::Init(dart::IsolateGroup*)+0x4ec

It looks like the DART_PRECOMPILER is not defined, but it should. (It works on Linux x64 targeting arm/arm64.)

So, we're done if we don't care about create_platform_sdk, and otherwise almost done.