Enable whole-program virtual function optimization in LTO mode.

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/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 # Contains the dependencies needed for sanitizers to link into executables and
 # shared_libraries. Unconditionally depend upon this target as it is empty if
@@ skipping 76 matching lines @@
     }
     if (is_msan) {
       ldflags += [ "-fsanitize=memory" ]
     }
     if (is_ubsan || is_ubsan_security) {
       ldflags += [ "-fsanitize=undefined" ]
     }
     if (is_ubsan_vptr) {
       ldflags += [ "-fsanitize=vptr" ]
     }
-    if (is_lto && !is_nacl) {
-      ldflags += [ "-flto" ]
 
-      # Apply a lower LTO optimization level as the default is too slow.
-      if (is_linux) {
-        ldflags += [ "-Wl,-plugin-opt,O1" ]
-      } else if (is_mac) {
-        ldflags += [ "-Wl,-mllvm,-O1" ]
-      }
-
-      # Work-around for http://openradar.appspot.com/20356002
-      if (is_mac) {
-        ldflags += [ "-Wl,-all_load" ]
-      }
-
-      # Without this flag, LTO produces a .text section that is larger
-      # than the maximum call displacement, preventing the linker from
-      # relocating calls (http://llvm.org/PR22999).
-      if (current_cpu == "arm") {
-        ldflags += [ "-Wl,-plugin-opt,-function-sections" ]
-      }
-
-      if (is_cfi) {
-        ldflags += [
-          "-fsanitize=cfi-vcall",
-          "-fsanitize=cfi-derived-cast",
-          "-fsanitize=cfi-unrelated-cast",
-        ]
-      }
-
+    if (is_cfi && !is_nacl) {
+      ldflags += [
+        "-fsanitize=cfi-vcall",
+        "-fsanitize=cfi-derived-cast",
+        "-fsanitize=cfi-unrelated-cast",
+      ]
       if (use_cfi_diag) {
         ldflags += [
           "-fno-sanitize-trap=cfi",
           "-fsanitize-recover=cfi",
         ]
       }
     }
   }
 }
 
@@ skipping 12 matching lines @@
 
   # Sanitizers need line table info for stack traces. They don't need type info
   # or variable info, so we can leave that out to speed up the build.
   if (using_sanitizer) {
     assert(is_clang, "sanitizers only supported with clang")
     cflags += [ "-gline-tables-only" ]
   }
 
   # Common options for AddressSanitizer, LeakSanitizer, ThreadSanitizer,
   # MemorySanitizer and non-official CFI builds.
-  if (using_sanitizer || (is_lto && !is_official_build)) {
+  if (using_sanitizer || (is_cfi && !is_official_build)) {
     if (is_posix) {
       cflags += [ "-fno-omit-frame-pointer" ]
     } else {
       cflags += [ "/Oy-" ]
     }
   }
   if (is_asan) {
     cflags += [ "-fsanitize=address" ]
     if (is_win) {
       cflags += [ "-fsanitize-blacklist=" +
@@ skipping 105 matching lines @@
     ]
   }
   if (is_ubsan_security) {
     ubsan_blacklist_path =
         rebase_path("//tools/ubsan/blacklist.txt", root_build_dir)
     cflags += [
       "-fsanitize=signed-integer-overflow",
       "-fsanitize-blacklist=$ubsan_blacklist_path",
     ]
   }
-  if (is_lto && !is_nacl) {
-    cflags += [ "-flto" ]
-
-    if (is_cfi) {
-      cfi_blacklist_path =
-          rebase_path("//tools/cfi/blacklist.txt", root_build_dir)
-      cflags += [
-        "-fsanitize=cfi-vcall",
-        "-fsanitize=cfi-derived-cast",
-        "-fsanitize=cfi-unrelated-cast",
-        "-fsanitize-blacklist=$cfi_blacklist_path",
-      ]
-    }
+  if (is_cfi && !is_nacl) {
+    cfi_blacklist_path =
+        rebase_path("//tools/cfi/blacklist.txt", root_build_dir)
+    cflags += [
+      "-fsanitize=cfi-vcall",
+      "-fsanitize=cfi-derived-cast",
+      "-fsanitize=cfi-unrelated-cast",
+      "-fsanitize-blacklist=$cfi_blacklist_path",
+    ]
 
     if (use_cfi_diag) {
       cflags += [
         "-fno-sanitize-trap=cfi",
         "-fsanitize-recover=cfi",
         "-fno-inline-functions",
         "-fno-inline",
         "-fno-omit-frame-pointer",
         "-O1",
       ]
@@ skipping 18 matching lines @@
 
   if (use_sanitizer_coverage) {
     # FIXME: make this configurable.
     cflags += [
       "-fsanitize-coverage=edge,indirect-calls,8bit-counters",
       "-mllvm",
       "-sanitizer-coverage-prune-blocks=1",
     ]
   }
 }