GN: Allow building without /build/ folder.

BUILD.gn

@@ -3,15 +3,18 @@
 # found in the LICENSE file.
 
 # import the use_x11 variable
-import("//build/config/linux/pkg_config.gni")
-import("//build/config/ui.gni")
-import("//testing/libfuzzer/fuzzer_test.gni")
 import("gni/angle.gni")
-if (is_android) {
-  # android/rules.gni can only be imported for Android targets
-  import("//build/config/android/config.gni")
-  import("//build/config/android/rules.gni")
-  import("android/angle_apk.gni")
+if (angle_has_build) {
+  import("//build/config/linux/pkg_config.gni")
+  import("//build/config/ui.gni")
+  import("//testing/libfuzzer/fuzzer_test.gni")
+
+  if (is_android) {
+    # android/rules.gni can only be imported for Android targets
+    import("//build/config/android/config.gni")
+    import("//build/config/android/rules.gni")
+    import("android/angle_apk.gni")
+  }
 }
 
 declare_args() {
@@ -28,7 +31,7 @@ declare_args() {
 
   # Don't build extra (test, samples etc) for Windows UWP. We don't have
   # infrastructure (e.g. windowing helper functions) in place to run them.
-  angle_build_all = !angle_is_winuwp
+  angle_build_all = !angle_is_winuwp && angle_has_build
 }
 
 if (!build_with_chromium && angle_build_all) {
@@ -159,9 +162,11 @@ config("better_linux_stack_traces") {
   }
 }
 
+_use_copy_compiler_dll = angle_has_build && is_win && target_cpu != "arm64"
+
 # Windows ARM64 is available since 10.0.16299 so no need to copy
 # d3dcompiler_47.dll because this file is available as inbox.
-if (is_win && target_cpu != "arm64") {
+if (_use_copy_compiler_dll) {
   # We also ship an older DLL for compatiblity with Windows 7 machines without
   # the UCRT. This DLL isn't available in the standard SDK distribution.
   _old_compiler = "$windows_sdk_path/Redist/D3D/$target_cpu/d3dcompiler_old.dll"
@@ -253,13 +258,15 @@ angle_source_set("xxhash") {
   configs -= [ "${angle_root}:extra_warnings" ]
 }
 
-fuzzer_test("xxhash_fuzzer") {
-  sources = [
-    "src/common/third_party/xxhash/xxhash_fuzzer.cpp",
-  ]
-  deps = [
-    ":xxhash",
-  ]
+if (angle_has_build) {
+  fuzzer_test("xxhash_fuzzer") {
+    sources = [
+      "src/common/third_party/xxhash/xxhash_fuzzer.cpp",
+    ]
+    deps = [
+      ":xxhash",
+    ]
+  }
 }
 
 angle_static_library("angle_common") {
@@ -281,7 +288,7 @@ angle_static_library("angle_common") {
   ]
   public_configs += [ ":angle_common_config" ]
   all_dependent_configs = [ ":angle_release_asserts_config" ]
-  if (use_fuzzing_engine) {
+  if (angle_has_build && use_fuzzing_engine) {
     all_dependent_configs += [ ":angle_disable_pool_alloc" ]
   }
 }
@@ -683,7 +690,7 @@ angle_source_set("libANGLE_base") {
 
   # Windows ARM64 is available since 10.0.16299 so no need to copy
   # d3dcompiler_47.dll because this file is available as inbox.
-  if (is_win && target_cpu != "arm64") {
+  if (_use_copy_compiler_dll) {
     data_deps = [
       ":copy_compiler_dll",
     ]
@@ -1121,45 +1128,47 @@ angle_executable("angle_shader_translator") {
   ]
 }
 
-config("angle_feature_support_config") {
-  include_dirs = [
-    "include",
-    "src",
-  ]
-  defines = [ "LIBFEATURE_SUPPORT_IMPLEMENTATION" ]
-  if (is_debug) {
-    defines += [ "ANGLE_FEATURE_UTIL_LOG_VERBOSE" ]
+if (angle_has_build) {
+  config("angle_feature_support_config") {
+    include_dirs = [
+      "include",
+      "src",
+    ]
+    defines = [ "LIBFEATURE_SUPPORT_IMPLEMENTATION" ]
+    if (is_debug) {
+      defines += [ "ANGLE_FEATURE_UTIL_LOG_VERBOSE" ]
+    }
   }
-}
-
-angle_shared_library("libfeature_support") {
-  output_name = "libfeature_support${angle_libs_suffix}"
 
-  if (is_android) {
-    libs = [ "log" ]
-  }
+  angle_shared_library("libfeature_support") {
+    output_name = "libfeature_support${angle_libs_suffix}"
 
-  public_configs += [
-    ":angle_feature_support_config",
-    "${angle_jsoncpp_dir}:jsoncpp_config",
-  ]
+    if (is_android) {
+      libs = [ "log" ]
+    }
 
-  if (is_mac && !is_component_build) {
-    ldflags = [
-      "-install_name",
-      "@rpath/${target_name}.dylib",
+    public_configs += [
+      ":angle_feature_support_config",
+      "${angle_jsoncpp_dir}:jsoncpp_config",
     ]
-  }
 
-  sources = [
-    "src/feature_support_util/feature_support_util.cpp",
-    "src/feature_support_util/feature_support_util.h",
-  ]
+    if (is_mac && !is_component_build) {
+      ldflags = [
+        "-install_name",
+        "@rpath/${target_name}.dylib",
+      ]
+    }
 
-  deps = [
-    ":angle_gpu_info_util",
-    "${angle_jsoncpp_dir}:jsoncpp",
-  ]
+    sources = [
+      "src/feature_support_util/feature_support_util.cpp",
+      "src/feature_support_util/feature_support_util.h",
+    ]
+
+    deps = [
+      ":angle_gpu_info_util",
+      "${angle_jsoncpp_dir}:jsoncpp",
+    ]
+  }
 }
 
 if (!is_component_build && is_android && symbol_level != 0) {
@@ -1226,3 +1235,11 @@ if (!is_component_build && is_android &&
     ]
   }
 }
+
+# Note: libGLESv1_CM is not presently included because most Chrome users don't care about it.
+group("angle") {
+  data_deps = [
+    ":libGLESv2",
+    ":libEGL",
+  ]
+}

build_overrides/angle.gni

@@ -5,6 +5,9 @@
 # Override for angle_root
 angle_root = "//"
 
+# True if ANGLE can access build/, testing/ and other Chrome folders.
+angle_has_build = true
+
 # Overrides for ANGLE's dependencies
 angle_glslang_dir = "//third_party/glslang/src"
 angle_googletest_dir = "//third_party/googletest/src"

gni/angle.gni

@@ -2,15 +2,32 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/dcheck_always_on.gni")
-import("//build/config/sanitizers/sanitizers.gni")
-import("//build/config/ui.gni")  # import the use_x11 variable
 import("//build_overrides/angle.gni")
-import("//build_overrides/build.gni")
-import("//build_overrides/swiftshader.gni")
-import("//testing/test.gni")
-if (is_android) {
-  import("//build/config/android/config.gni")
+
+if (angle_has_build) {
+  import("//build/config/dcheck_always_on.gni")
+  import("//build/config/sanitizers/sanitizers.gni")
+  import("//build/config/ui.gni")  # import the use_x11 variable
+  import("//build_overrides/build.gni")
+  import("//testing/test.gni")
+  if (is_android) {
+    import("//build/config/android/config.gni")
+  }
+
+  if (is_win) {
+    import("//build/config/win/visual_studio_version.gni")
+  }
+} else {
+  declare_args() {
+    is_ubsan = false
+    is_tsan = false
+    is_asan = false
+    build_with_chromium = false
+    dcheck_always_on = false
+    use_x11 = is_linux
+    use_ozone = false
+    use_fuzzing_engine = false
+  }
 }
 
 if (build_with_chromium) {
@@ -70,8 +87,9 @@ declare_args() {
   # Vulkan Validation Layers compatibility issues, see http://crrev/c/1405714.
   # Otherwise, API level 24 would have been enough.
   angle_enable_vulkan =
-      (is_win && !angle_is_winuwp) || (is_linux && use_x11 && !is_chromeos) ||
-      (is_android && ndk_api_level_at_least_26) || is_fuchsia
+      angle_has_build &&
+      ((is_win && !angle_is_winuwp) || (is_linux && use_x11 && !is_chromeos) ||
+       (is_android && ndk_api_level_at_least_26) || is_fuchsia)
   angle_enable_null = true
   angle_enable_essl = true
   angle_enable_glsl = true
@@ -91,21 +109,21 @@ declare_args() {
   angle_enable_overlay = false
 }
 
-if (is_win) {
-  import("//build/config/win/visual_studio_version.gni")
-}
-
 angle_common_configs = [
   angle_root + ":better_linux_stack_traces",
   angle_root + ":extra_warnings",
   angle_root + ":internal_config",
 ]
 
-angle_remove_configs = [ "//build/config/compiler:default_include_dirs" ]
+angle_remove_configs = []
+
+if (angle_has_build) {
+  angle_remove_configs += [ "//build/config/compiler:default_include_dirs" ]
+}
 angle_better_stack_traces =
     (is_debug || dcheck_always_on) && is_linux && !is_asan && !is_cfi
 
-if (is_clang) {
+if (angle_has_build && is_clang) {
   angle_remove_configs += [ "//build/config/clang:find_bad_constructs" ]
 
   # Disabled to enable better stack traces.

src/libANGLE/renderer/vulkan/BUILD.gn

@@ -4,6 +4,7 @@
 #
 # This file houses the build configuration for the ANGLE Vulkan back-end.
 
+import("//build_overrides/swiftshader.gni")
 import("../../../../gni/angle.gni")
 
 assert(angle_enable_vulkan)