Win/GN: Make no_exception config explicit.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 1126 matching lines @@
   if (!use_cfi_diag && !is_ubsan_vptr && !is_ubsan_security) {
     if (is_win) {
       cflags_cc = [ "/GR-" ]
     } else {
       cflags_cc = [ "-fno-rtti" ]
       cflags_objcc = cflags_cc
     }
   }
 }
 
+# exceptions -------------------------------------------------------------------
+#
+# Allows turning exceptions on or off.

[brettw, 2016/08/31 17:01:20]

Can this comment be a little more precise? This will disable exceptions when
applied, which are normally enabled in C++.

+
+config("no_exceptions") {
+  if (is_posix) {
+    cflags_cc = [ "-fno-exceptions" ]
+    cflags_objcc = cflags_cc
+  }
+  if (is_win) {
+    defines = [ "_HAS_EXCEPTIONS=0" ]
+  }
+}
+
 # Warnings ---------------------------------------------------------------------
 
 # This will generate warnings when using Clang if code generates exit-time
 # destructors, which will slow down closing the program.
 # TODO(thakis): Make this a blacklist instead, http://crbug.com/101600
 config("wexit_time_destructors") {
   # TODO: Enable on Windows too, http://crbug.com/404525
   if (is_clang && !is_win) {
     cflags = [ "-Wexit-time-destructors" ]
   }
@@ skipping 411 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }