GN Build fixes for Flutter + gen_snapshot fix

runtime/BUILD.gn

Index: runtime/BUILD.gn
diff --git a/runtime/BUILD.gn b/runtime/BUILD.gn
index d4cd0bccf55b79682ae4836a590c4ef91ff591a9..bd091d9ae67f4d8a9e75022ed480d0d5961f509c 100644
--- a/runtime/BUILD.gn
+++ b/runtime/BUILD.gn
@@ -12,9 +12,15 @@ declare_args() {
   # 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"
 
   # Explicitly set the target architecture in case of precompilation. Leaving
   # this unspecified results in automatic target architecture detection.
@@ -28,79 +34,59 @@ config("dart_public_config") {
   ]
 }
 
-config("dart_config") {
+# Controls PRODUCT #define.
+config("dart_product_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 if (dart_target_arch == "dbc") {
-      defines += [ "TARGET_ARCH_DBC" ]
-    } else  {
-      print("Invalid |dart_target_arch|")
-      assert(false)
-    }
-  }
-
-  if (dart_debug) {
-    defines += ["DEBUG"]
-  } else {
-    defines += ["NDEBUG"]
+  if ((dart_runtime_mode != "develop") &&
+      (dart_runtime_mode != "profile") &&
+      (dart_runtime_mode != "release")) {
+    print("Invalid |dart_runtime_mode|")
+    assert(false)
   }
 
-  if (dart_product) {
+  if (dart_runtime_mode == "release") {
     if (dart_debug) {
-      print("Debug and product mode are mutually exclusive.")
+      print("Debug and release mode are mutually exclusive.")
     }
     assert(!dart_debug)
     defines += ["PRODUCT"]
   }
+}
 
-  # 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",
-  ]
+# Controls DART_PRECOMPILED_RUNTIME #define.
+config("dart_precompiled_runtime_config") {
+  defines = []
 
-  if (dart_debug) {
-    cflags += [
-      "-O1",
-    ]
-  } else {
-    cflags += [
-      "-O3",
-    ]
+  if ((dart_runtime_mode != "develop") &&
+      (dart_runtime_mode != "profile") &&
+      (dart_runtime_mode != "release")) {
+    print("Invalid |dart_runtime_mode|")
+    assert(false)
   }
 
-  if (is_asan) {
-    ldflags = [
-      "-Wl,-u_sanitizer_options_link_helper",
-      "-fsanitize=address",
-    ]
+  if (dart_runtime_mode == "release") {
+    if (dart_debug) {
+      print("Debug and release mode are mutually exclusive.")
+    }
+    assert(!dart_debug)
+    defines += ["DART_PRECOMPILED_RUNTIME"]
+  } else if (dart_runtime_mode == "profile") {
+    if (dart_debug) {
+      print("Debug and profile mode are mutually exclusive.")
+    }
+    assert(!dart_debug)
+    defines += ["DART_PRECOMPILED_RUNTIME"]
   }
 }
 
-config("dart_config_no_precompiler") {
+# Controls DART_PRECOMPILER #define.
+config("dart_precompiler_config") {
+  defines = []
+  defines += ["DART_PRECOMPILER"]
+}
+
+config("dart_config") {
   defines = []
 
   if (dart_target_arch != "") {
@@ -128,14 +114,6 @@ config("dart_config_no_precompiler") {
     defines += ["NDEBUG"]
   }
 
-  if (dart_product) {
-    if (dart_debug) {
-      print("Debug and product mode are mutually exclusive.")
-    }
-    assert(!dart_debug)
-    defines += ["PRODUCT"]
-  }
-
   cflags = [
     "-Werror",
     "-Wall",
@@ -169,9 +147,10 @@ config("dart_config_no_precompiler") {
   }
 }
 
-
 static_library("libdart") {
-  configs += [":dart_config"]
+  configs += [":dart_config",
+              ":dart_product_config",
+              ":dart_precompiled_runtime_config"]
   deps = [
     "vm:libdart_lib",
     "vm:libdart_vm",
@@ -196,37 +175,6 @@ static_library("libdart") {
   ]
 }
 
-
-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",
@@ -251,7 +199,9 @@ action("generate_version_cc_file") {
 
 
 executable("libdart_dependency_helper") {
-  configs += [":dart_config"]
+  configs += [":dart_config",
+              ":dart_product_config",
+              ":dart_precompiled_runtime_config"]
   deps = [
     "vm:libdart_lib_nosnapshot",
     "vm:libdart_lib",