gn build: Add check-hwasan target.

[pcc]

Summary

The Android sanitizer tests are currently some of the most difficult
to run correctly, requiring at least 3 build directories which have
to be configured in just the right way and built in the correct order
(see e.g. [1] and the functions that it calls).

This patch adds a check-hwasan target which greatly simplifies running
the hwasan tests for gn users, taking advantage of its support for
multiple toolchains. With this the tests can be run simply by setting
an NDK path and running "ninja check-hwasan" with a compatible Android
device connected. The Linux/x86_64 and Android/aarch64 targets are
tested in parallel.

[1] https://github.com/llvm/llvm-zorg/blob/master/zorg/buildbot/builders/sanitizers/buildbot_android.sh

[thakis]

Nice!!

llvm/utils/gn/secondary/compiler-rt/test/hwasan/BUILD.gn

47

Why do you need the android special case here?

llvm/utils/gn/secondary/compiler-rt/test/test.gni

15

Oooh I guess this would be tricky to do when using GN's config stuff for target flags. Hmm…

[pcc]

llvm/utils/gn/secondary/compiler-rt/test/hwasan/BUILD.gn

47

Digging into this more I suppose it's more like a special case for running the tests on the host (I'll adjust the condition here and add a FIXME to make that clear). The reason why it's necessary is that the sanitizer runtime will expect to find llvm-symbolizer in llvm_tools_dir (via $PATH) when running the tests natively because of this code here:
http://llvm-cs.pcc.me.uk/projects/compiler-rt/test/lit.common.cfg#88
The lit code also expects to be able to find other tools like lld-link and llvm-config (and I believe the compiler as well) in the same location, so the way things work now it needs to point to the host toolchain (unless we want to do a two-stage bootstrap just to run the sanitizer tests, which seems like something that we could support but most likely controlled by an is_bootstrap_build type thing in args.gn).

Either way the host toolchain binary isn't going to work on a non-native architecture because the architecture of llvm-config has to match the architecture of the sanitizer. So it seems like we should aim to make native consistent with non-native by always using //llvm/tools/llvm-symbolizer here and adjusting lit to use the stage2 llvm-symbolizer binary in native builds.

llvm/utils/gn/secondary/BUILD.gn

 import("//clang/lib/ARCMigrate/enable.gni")
 import("//clang/lib/StaticAnalyzer/Frontend/enable.gni")
 import("//llvm/utils/gn/build/toolchain/compiler.gni")
 
 group("default") {
   deps = [
     "//clang/test",
+    "//compiler-rt/test/hwasan",
     "//lld/test",
     "//llvm/test",
   ]
 
-  # FIXME: This should be a dependency of a test target instead of being
-  # depended on from here.
-  if (android_ndk_path != "") {
-    android_aarch64_toolchain =
-        "//llvm/utils/gn/build/toolchain:stage2_android_aarch64"
-    deps += [
-      "//compiler-rt/lib/hwasan:hwasan_shared($android_aarch64_toolchain)",
-      "//llvm/tools/llvm-symbolizer($android_aarch64_toolchain)",
-    ]
-  }
-  if (host_cpu == "x64" && host_os == "linux") {
-    deps += [ "//compiler-rt/lib/hwasan:hwasan_shared(//llvm/utils/gn/build/toolchain:stage2_unix)" ]
-  }
-
   testonly = true
 }
 
 # Symlink handling.
 # On POSIX, symlinks to the target can be created before the target exist,
 # and the target can depend on the symlink targets, so that building the
 # target ensures the symlinks exist.
 # However, symlinks didn't exist on Windows until recently, so there the

llvm/utils/gn/secondary/compiler-rt/include/BUILD.gn

+import("//llvm/resource_dir.gni")
+
+copy("include") {
+  sources = [
+    "sanitizer/allocator_interface.h",
+    "sanitizer/asan_interface.h",
+    "sanitizer/common_interface_defs.h",
+    "sanitizer/coverage_interface.h",
+    "sanitizer/dfsan_interface.h",
+    "sanitizer/esan_interface.h",
+    "sanitizer/hwasan_interface.h",
+    "sanitizer/linux_syscall_hooks.h",
+    "sanitizer/lsan_interface.h",
+    "sanitizer/msan_interface.h",
+    "sanitizer/netbsd_syscall_hooks.h",
+    "sanitizer/scudo_interface.h",
+    "sanitizer/tsan_interface.h",
+    "sanitizer/tsan_interface_atomic.h",
+    "xray/xray_interface.h",
+    "xray/xray_log_interface.h",
+    "xray/xray_records.h",
+  ]
+  outputs = [
+    "$llvm_resource_dir/include/{{source_target_relative}}",
+  ]
+}

llvm/utils/gn/secondary/compiler-rt/lib/cfi/BUILD.gn

+import("//llvm/resource_dir.gni")
+
+copy("blacklist") {
+  sources = [
+    "cfi_blacklist.txt",
+  ]
+  outputs = [
+    "$llvm_resource_dir/share/{{source_target_relative}}",
+  ]
+}

llvm/utils/gn/secondary/compiler-rt/test/BUILD.gn

+import("//compiler-rt/target.gni")
+import("//compiler-rt/test/test.gni")
+import("//llvm/triples.gni")
+import("//llvm/utils/gn/build/toolchain/compiler.gni")
+import("//llvm/utils/gn/build/write_cmake_config.gni")
+import("//llvm/version.gni")
+
+write_cmake_config("lit_common_configured") {
+  input = "lit.common.configured.in"
+  output = "$target_gen_dir/lit.common.configured"
+
+  values = [
+    "LIT_SITE_CFG_IN_HEADER=## Autogenerated from $input, do not edit",
+
+    "COMPILER_RT_DEFAULT_TARGET_TRIPLE=$llvm_current_triple",
+    "COMPILER_RT_DEFAULT_TARGET_ARCH=$crt_current_target_arch",
+
+    "COMPILER_RT_TEST_COMPILER_CFLAGS=$target_flags_string",
+    "LLVM_BUILD_MODE=.",
+    "LLVM_MAIN_SRC_DIR=" + rebase_path("//llvm"),
+    "LLVM_BINARY_DIR=" + rebase_path(root_build_dir),
+    "COMPILER_RT_SOURCE_DIR=" + rebase_path("//compiler-rt"),
+
+    # This is only used by tsan to find the path to an instrumented libc++.
+    # Since we don't currently support running the tsan tests, leave it empty
+    # for now. Eventually it should probably be replaced with some mechanism
+    # where the libraries are found in a toolchain dir.
+    "COMPILER_RT_BINARY_DIR=",
+
+    # We don't currently support the multiarch runtime layout.
+    "LLVM_ENABLE_PER_TARGET_RUNTIME_DIR_PYBOOL=False",
+
+    "LLVM_TOOLS_DIR=" + rebase_path("$root_build_dir/bin"),
+    "LLVM_LIBRARY_OUTPUT_INTDIR=" + rebase_path("$root_build_dir/lib"),
+
+    "GOLD_EXECUTABLE=ld",
+    "COMPILER_RT_RESOLVED_TEST_COMPILER=" +
+        rebase_path("$root_build_dir/bin/clang"),
+    "COMPILER_RT_TEST_COMPILER_ID=Clang",
+    "PYTHON_EXECUTABLE=$python_path",
+    "COMPILER_RT_DEBUG_PYBOOL=False",
+    "COMPILER_RT_RESOLVED_LIBRARY_OUTPUT_DIR=" +
+        rebase_path(crt_current_out_dir),
+    "COMPILER_RT_EMULATOR=",
+    "COMPILER_RT_ASAN_SHADOW_SCALE=",
+    "SANITIZER_CAN_USE_CXXABI_PYBOOL=True",
+    "COMPILER_RT_HAS_LLD_PYBOOL=True",
+    "HAVE_RPC_XDR_H=0",
+    "ANDROID_SERIAL_FOR_TESTING=$android_serial_for_testing",
+  ]
+
+  if (host_cpu == "x64") {
+    values += [ "HOST_ARCH=x86_64" ]
+  } else {
+    assert(false, "unimplemented host_cpu " + host_cpu)
+  }
+
+  if (host_os == "mac") {
+    values += [ "HOST_OS=Darwin" ]
+  } else if (host_os == "linux") {
+    values += [ "HOST_OS=Linux" ]
+  } else if (host_os == "win") {
+    values += [ "HOST_OS=Windows" ]
+  } else {
+    assert(false, "unsupported host_os " + host_os)
+  }
+
+  if (current_os != "win" || llvm_enable_dia_sdk) {
+    values += [ "CAN_SYMBOLIZE=1" ]
+  } else {
+    values += [ "CAN_SYMBOLIZE=0" ]
+  }
+
+  if (current_os == "android") {
+    values += [ "ANDROID_PYBOOL=True" ]
+  } else {
+    values += [ "ANDROID_PYBOOL=False" ]
+  }
+}

llvm/utils/gn/secondary/compiler-rt/test/hwasan/BUILD.gn

+import("//compiler-rt/target.gni")
+import("//compiler-rt/test/test.gni")
+import("//llvm/utils/gn/build/toolchain/compiler.gni")
+import("//llvm/utils/gn/build/write_cmake_config.gni")
+import("//llvm/version.gni")
+
+write_cmake_config("lit_site_cfg") {
+  input = "lit.site.cfg.in"
+  output = "$target_gen_dir/lit.site.cfg"
+
+  values = [
+    "LIT_SITE_CFG_IN_HEADER=## Autogenerated from $input, do not edit",
+
+    "HWASAN_TEST_CONFIG_SUFFIX=-$crt_current_target",
+    "HWASAN_TEST_TARGET_CFLAGS=$target_flags_string",
+    "HWASAN_TEST_TARGET_ARCH=$crt_current_target_arch",
+
+    "COMPILER_RT_BINARY_DIR=" + rebase_path("$root_gen_dir/compiler-rt"),
+    "HWASAN_LIT_SOURCE_DIR=" + rebase_path("."),
+  ]
+
+  if (current_os == "android") {
+    values += [ "HWASAN_ANDROID_FILES_TO_PUSH=[\"" + rebase_path(
+                    "$crt_current_out_dir/libclang_rt.hwasan-$crt_current_target.so") + "\", \"" + rebase_path(
+                    "$root_out_dir/bin/llvm-symbolizer") + "\"]" ]
+  } else {
+    values += [ "HWASAN_ANDROID_FILES_TO_PUSH=[]" ]
+  }
+}
+
+if (current_toolchain != host_toolchain) {
+  group("hwasan_toolchain") {
+    deps = [
+      ":lit_site_cfg",
+      "//compiler-rt/include($host_toolchain)",
+      "//compiler-rt/lib/cfi:blacklist($host_toolchain)",
+      "//compiler-rt/lib/hwasan:hwasan_shared",
+      "//compiler-rt/test:lit_common_configured",
+      "//llvm/utils/FileCheck($host_toolchain)",
+      "//llvm/utils/llvm-lit($host_toolchain)",
+      "//llvm/utils/not($host_toolchain)",
+    ]
+
+    if (current_os == "android") {
+      deps += [ "//llvm/tools/llvm-symbolizer" ]
+    } else {
+      deps += [ "//llvm/tools/llvm-symbolizer($host_toolchain)" ]
+    }
+  }
+}
+
+supported_toolchains = []
+if (host_os == "linux" && host_cpu == "x64") {
+  supported_toolchains += [ "//llvm/utils/gn/build/toolchain:stage2_unix" ]
+}
+if (android_ndk_path != "") {
+  supported_toolchains +=
+      [ "//llvm/utils/gn/build/toolchain:stage2_android_aarch64" ]
+}
+
+group("hwasan") {
+  deps = []
+  foreach(toolchain, supported_toolchains) {
+    deps += [ ":hwasan_toolchain($toolchain)" ]
+  }
+}
+
+if (supported_toolchains != []) {
+  action("check-hwasan") {
+    script = "$root_build_dir/bin/llvm-lit"
+    if (host_os == "win") {
+      script += ".py"
+    }
+    args = [ "-sv" ]
+    foreach(toolchain, supported_toolchains) {
+      args += [ rebase_path(
+              get_label_info(":lit_site_cfg($toolchain)", "target_gen_dir"),
+              root_build_dir) ]
+    }
+    outputs = [
+      "$target_gen_dir/run-lit",  # Non-existing, so that ninja runs it each time.
+    ]
+
+    # Since check-hwasan is always dirty, //:default doesn't depend on it so that
+    # it's not part of the default ninja target.  Hence, check-hwasan shouldn't
+    # have any deps except :hwasan. so that the default target is sure to build
+    # all the deps.
+    deps = [
+      ":hwasan",
+    ]
+    testonly = true
+
+    pool = "//:console"
+  }
+}

llvm/utils/gn/secondary/compiler-rt/test/test.gni

+import("//llvm/utils/gn/build/toolchain/target_flags.gni")
+
+declare_args() {
+  # Specifies the serial number of the Android device to be used for testing.
+  android_serial_for_testing = ""
+}
+
+target_flags_string = ""
+
+foreach(flag,
+        target_flags + target_cflags + target_ldflags + [ "-fuse-ld=lld" ]) {
+  if (target_flags_string != "") {
+    target_flags_string += " "
+  }
+  target_flags_string += flag
+}