GN: Add an explicit gn arg for recovery in CFI

build/config/sanitizers/BUILD.gn

 # Copyright 2014 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_overrides/build.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/clang/clang.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 200 matching lines @@
 
     if (is_cfi && !is_nacl) {
       ldflags += [ "-fsanitize=cfi-vcall" ]
       if (use_cfi_cast) {
         ldflags += [
           "-fsanitize=cfi-derived-cast",
           "-fsanitize=cfi-unrelated-cast",
         ]
       }
       if (use_cfi_diag) {
-        ldflags += [
-          "-fno-sanitize-trap=cfi",
-          "-fsanitize-recover=cfi",
-        ]
+        ldflags += [ "-fno-sanitize-trap=cfi" ]
+        if (use_cfi_recover) {
+          ldflags += [ "-fsanitize-recover=cfi" ]
+        }
       }
     }
   } else if (is_win && is_asan) {
     # Windows directly calls link.exe instead of the compiler driver when
     # linking.  Hence, pass the runtime libraries instead of -fsanitize=address.
     # In the static-library build, libraries are different for executables
     # and dlls, see link_executable and link_shared_library below.
     # This here handles only the component build.
     if (target_cpu == "x64") {
       # Windows 64-bit. TODO(etienneb): Remove the assert when this is ready.
@@ skipping 140 matching lines @@
       ]
     }
 
     if (use_cfi_icall) {
       cflags += [ "-fsanitize=cfi-icall" ]
     }
 
     if (use_cfi_diag) {
       cflags += [
         "-fno-sanitize-trap=cfi",
-        "-fsanitize-recover=cfi",
         "-fno-inline-functions",
         "-fno-inline",
         "-fno-omit-frame-pointer",
         "-O1",
       ]
+      if (use_cfi_recover) {
+        cflags += [ "-fsanitize-recover=cfi" ]
+      }
     } else {
       defines = [ "CFI_ENFORCEMENT" ]
     }
   }
 }
 
 config("coverage_flags") {
   cflags = []
 
   if (use_sanitizer_coverage) {
@@ skipping 169 matching lines @@
 # This allows to selectively disable ubsan_vptr, when needed. In particular,
 # if some third_party code is required to be compiled without rtti, which
 # is a requirement for ubsan_vptr.
 config("default_sanitizer_flags_but_ubsan_vptr") {
   configs = all_sanitizer_configs - [ ":ubsan_vptr_flags" ]
 }
 
 config("default_sanitizer_flags_but_coverage") {
   configs = all_sanitizer_configs - [ ":coverage_flags" ]
 }