gn win: Enable exceptions for pdfium build

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")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
@@ skipping 36 matching lines @@
   # GCC flags, and then we handle the other non-Windows platforms specifically
   # below.
   if (is_win) {
     # Windows compiler flags setup.
     # -----------------------------
     cflags += [
       "/Gy",  # Enable function-level linking.
       "/GS",  # Enable buffer security checking.
       "/FS",  # Preserve previous PDB behavior.
     ]
-    if (is_component_build) {
-      cflags += [
-        "/EHsc",  # Assume C functions can't throw exceptions and don't catch
-                  # structured exceptions (only C++ ones).
-      ]
-    }
   } else {
     # Common GCC compiler flags setup.
     # --------------------------------
     cflags += [
       "-fno-strict-aliasing",  # See http://crbug.com/32204
     ]
     cflags_cc += [
       "-fno-threadsafe-statics",
       # Not exporting C++ inline functions can generally be applied anywhere
       # so we do so here. Normal function visibility is controlled by
@@ skipping 273 matching lines @@
       # about things not matching, so keep exceptions on.
       if (is_debug) {
         cflags += [ "/MDd" ]
       } else {
         cflags += [ "/MD" ]
       }
     }
   } else {
     # Static CRT.
     if (is_win) {
-      # We don't use exceptions, and when we link statically we can just get
-      # rid of them entirely.
-      defines += [ "_HAS_EXCEPTIONS=0" ]
       if (is_debug) {
         cflags += [ "/MTd" ]
       } else {
         cflags += [ "/MT" ]
       }
     }
   }
 
   if (is_win) {
     defines += [
@@ skipping 187 matching lines @@
   }
 }
 config("no_rtti") {
   if (is_win) {
     cflags_cc = [ "/GR-" ]
   } else {
     cflags_cc = [ "-fno-rtti" ]
   }
 }
 
+# Exceptions -------------------------------------------------------------------
+
+# Some code requires turning exceptions back on (off is the default).
+
+config("no_exceptions") {
+  if (is_win) {
+    defines = [ "_HAS_EXCEPTIONS=0" ]
+  } else if (is_posix) {
+    cflags_cc = [ "-fno-exceptions" ]
+  }
+}
+
+config("exceptions") {
+  if (is_win) {
+    cflags = [
+      "/EHsc",  # Assume C functions can't throw exceptions and don't catch
+                # structured exceptions (only C++ ones).
+    ]
+  }
+}
+
 # Warnings ---------------------------------------------------------------------
 #
 # This is where we disable various warnings that we've decided aren't
 # worthwhile, and enable special warnings.
 
 config("default_warnings") {
   if (is_win) {
     cflags = [
       "/WX",      # Treat warnings as errors.
 
@@ skipping 314 matching lines @@
   } else {
     cflags = [ "-g1" ]
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }