GN Build fixes for Flutter + gen_snapshot fix

runtime/BUILD.gn

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # TODO(zra): These build arguments should likely be moved to a gni file that is
 # included in BUILD.gn files that care about the values of the flags. For now,
 # since the GN build only happens as part of a Mojo build there is no need for
 # the indirection.
 declare_args() {
   # Instead of using is_debug, we introduce a different flag for specifying a
   # Debug build of Dart so that clients can still use a Release build of Dart
   # while themselves doing a Debug build.
   dart_debug = false
 
-  # Product mode drops many features (e.g. debugger, profiler, etc) in order to
-  # shrink download size and decrease memory and cpu usage.
-  dart_product = false
+  # Set the runtime mode. This affects how the runtime is built and what
+  # features it has. Valid values are:
+  # 'develop' (the default) - VM is built to run as a JIT with all development
+  # features enabled.
+  # 'profile' - The VM is built to run with AOT compiled code with only the
+  # CPU profiling features enabled.
+  # 'release' - The VM is built to run with AOT compiled code with no developer
+  # features enabled.
+  dart_runtime_mode = "develop"
+
+  # Controls whether or not the Dart AOT compiler is part of the built runtime.
+  dart_include_aot_compiler = false
 
   # Explicitly set the target architecture in case of precompilation. Leaving
   # this unspecified results in automatic target architecture detection.
   # Available options are: arm, arm64, mips, x64 and ia32
   dart_target_arch = ""
 }
 
 config("dart_public_config") {
   include_dirs = [
     ".",
   ]
 }
 
 config("dart_config") {
   defines = []
 
-  if (dart_target_arch != "") {
-    if (dart_target_arch == "arm") {
-      defines += [ "TARGET_ARCH_ARM" ]
-    } else if (dart_target_arch == "arm64") {
-      defines += [ "TARGET_ARCH_ARM64" ]
-    } else if (dart_target_arch == "mips") {
-      defines += [ "TARGET_ARCH_MIPS" ]
-    } else if (dart_target_arch == "x64") {
-      defines += [ "TARGET_ARCH_X64" ]
-    } else if (dart_target_arch == "ia32") {
-      defines += [ "TARGET_ARCH_IA32" ]
-    } else  {
-      print("Invalid |dart_target_arch|")
-      assert(false)
-    }
+  if ((dart_runtime_mode != "develop") &&
+      (dart_runtime_mode != "profile") &&
+      (dart_runtime_mode != "release")) {
+    print("Invalid |dart_runtime_mode|")
+    assert(false)
   }
 
-  if (dart_debug) {
-    defines += ["DEBUG"]
-  } else {
-    defines += ["NDEBUG"]
+  if (dart_runtime_mode == "release") {
+    if (dart_debug) {
+      print("Debug and release mode are mutually exclusive.")
+    }
+    assert(!dart_debug)
+    defines += ["DART_PRECOMPILED_RUNTIME"]
+    defines += ["PRODUCT"]
+  } else if (dart_runtime_mode == "profile") {
+    if (dart_debug) {
+      print("Debug and profile mode are mutually exclusive.")
+    }
+    assert(!dart_debug)
+    defines += ["DART_PRECOMPILED_RUNTIME"]
   }
 
-  if (dart_product) {
-    if (dart_debug) {
-      print("Debug and product mode are mutually exclusive.")
-    }
-    assert(!dart_debug)
-    defines += ["PRODUCT"]
+  if (dart_include_aot_compiler) {
+    defines += ["DART_PRECOMPILER"]
   }
 
-  # Ideally this would only be enabled for gen_snapshot
-  defines += ["DART_PRECOMPILER"]
-
-  cflags = [
-    "-Werror",
-    "-Wall",
-    "-Wextra", # Also known as -W.
-    "-Wno-unused-parameter",
-    "-Wnon-virtual-dtor",
-    "-Wvla",
-    "-Wno-conversion-null",
-    "-Woverloaded-virtual",
-    "-g3",
-    "-ggdb3",
-    "-fno-rtti",
-    "-fno-exceptions",
-  ]
-
-  if (dart_debug) {
-    cflags += [
-      "-O1",
-    ]
-  } else {
-    cflags += [
-      "-O3",
-    ]
-  }
-
-  if (is_asan) {
-    ldflags = [
-      "-Wl,-u_sanitizer_options_link_helper",
-      "-fsanitize=address",
-    ]
-  }
-}
-
-config("dart_config_no_precompiler") {
-  defines = []
-
   if (dart_target_arch != "") {
     if (dart_target_arch == "arm") {
       defines += [ "TARGET_ARCH_ARM" ]
     } else if (dart_target_arch == "arm64") {
       defines += [ "TARGET_ARCH_ARM64" ]
     } else if (dart_target_arch == "mips") {
       defines += [ "TARGET_ARCH_MIPS" ]
     } else if (dart_target_arch == "x64") {
       defines += [ "TARGET_ARCH_X64" ]
     } else if (dart_target_arch == "ia32") {
       defines += [ "TARGET_ARCH_IA32" ]
     } else  {
       print("Invalid |dart_target_arch|")
       assert(false)
     }
   }
 
   if (dart_debug) {
     defines += ["DEBUG"]
   } else {
     defines += ["NDEBUG"]
   }
 
-  if (dart_product) {
-    if (dart_debug) {
-      print("Debug and product mode are mutually exclusive.")
-    }
-    assert(!dart_debug)
-    defines += ["PRODUCT"]
-  }
-
   cflags = [
     "-Werror",
     "-Wall",
     "-Wextra", # Also known as -W.
     "-Wno-unused-parameter",
     "-Wnon-virtual-dtor",
     "-Wvla",
     "-Wno-conversion-null",
     "-Woverloaded-virtual",
     "-g3",
@@ skipping 13 matching lines @@
   }
 
   if (is_asan) {
     ldflags = [
       "-Wl,-u_sanitizer_options_link_helper",
       "-fsanitize=address",
     ]
   }
 }
 
-
 static_library("libdart") {
   configs += [":dart_config"]
   deps = [
     "vm:libdart_lib",
     "vm:libdart_vm",
     "third_party/double-conversion/src:libdouble_conversion",
     ":generate_version_cc_file",
   ]
   include_dirs = [
     ".",
   ]
   public_configs = [":dart_public_config"]
   sources = [
     "include/dart_api.h",
     "include/dart_mirrors_api.h",
     "include/dart_native_api.h",
     "include/dart_tools_api.h",
     "vm/dart_api_impl.cc",
     "vm/debugger_api_impl.cc",
     "vm/mirrors_api_impl.cc",
     "vm/native_api_impl.cc",
     "vm/version.h",
     "$target_gen_dir/version.cc",
   ]
 }
 
 
-static_library("libdart_precompiled_runtime") {
-  configs += [":dart_config_no_precompiler"]
-  deps = [
-    "vm:libdart_lib_precompiled_runtime",
-    "vm:libdart_vm_precompiled_runtime",
-    "third_party/double-conversion/src:libdouble_conversion",
-    ":generate_version_cc_file",
-  ]
-  include_dirs = [
-    ".",
-  ]
-  public_configs = [":dart_public_config"]
-  sources = [
-    "include/dart_api.h",
-    "include/dart_mirrors_api.h",
-    "include/dart_native_api.h",
-    "include/dart_tools_api.h",
-    "vm/dart_api_impl.cc",
-    "vm/debugger_api_impl.cc",
-    "vm/mirrors_api_impl.cc",
-    "vm/native_api_impl.cc",
-    "vm/version.h",
-    "$target_gen_dir/version.cc",
-  ]
-  defines = [
-    "DART_PRECOMPILED_RUNTIME",
-  ]
-}
-
-
 action("generate_version_cc_file") {
   deps = [
     ":libdart_dependency_helper",
   ]
   inputs = [
     "../tools/utils.py",
     "../tools/print_version.py",
     "../tools/VERSION",
     "vm/version_in.cc",
   ]
@@ skipping 16 matching lines @@
     "vm:libdart_lib_nosnapshot",
     "vm:libdart_lib",
     "vm:libdart_vm",
     "vm:libdart_platform",
     "third_party/double-conversion/src:libdouble_conversion",
   ]
   sources = [
     "vm/libdart_dependency_helper.cc",
   ]
 }