Move stripping of debug symbols on linux behind a flag

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 74 matching lines @@
 
   # AFDO (Automatic Feedback Directed Optimizer) is a form of profile-guided
   # optimization that GCC supports. It used by ChromeOS in their official
   # builds. To use it, set auto_profile_path to the path to a file containing
   # the needed gcov profiling data.
   auto_profile_path = ""
 
   # Optimize for coverage guided fuzzing (balance between speed and number of
   # branches)
   optimize_for_fuzzing = false
+
+  if (is_clang && is_linux) {
+    strip_absolute_paths_from_debug_symbols = false

[brettw, 2017/02/15 22:48:56]

Can you add a comment above this (inside the condition) that explains why
somebody might want to use this?

+  }
 }
 
 if (is_clang && !is_nacl) {
   update_args = [ "--print-revision" ]
   if (llvm_force_head_revision) {
     update_args += [ "--llvm-force-head-revision" ]
   }
   clang_revision =
       exec_script("//tools/clang/scripts/update.py", update_args, "trim string")
 }
@@ skipping 313 matching lines @@
   # on Linux/Mac (GCC doesn't support it), but MSVC does this with /FC and
   # Windows developers rely on it (crbug.com/636109) so only do this on Windows.
   if (is_clang && is_win) {
     cflags += [ "-fdiagnostics-absolute-paths" ]
   }
 
   # Makes builds independent of absolute file path.
   # clang-cl (used if is_win) doesn't expose this flag.
   # Currently disabled for nacl since its toolchain lacks this flag (too old).
   # TODO(zforman): Once nacl's toolchain is updated, remove check.
-  if (is_clang && is_linux) {
+  if (is_clang && is_linux && strip_absolute_paths_from_debug_symbols) {
     absolute_path = rebase_path("//.")
     cflags += [ "-fdebug-prefix-map=$absolute_path=." ]
   }
 
   # C++11 compiler flags setup.
   # ---------------------------
   if (is_linux || is_android || (is_nacl && is_clang)) {
     # gnu++11 instead of c++11 is needed because some code uses typeof() (a
     # GNU extension).
     # TODO(thakis): Eventually switch this to c++11 instead,
@@ skipping 1259 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
   }
 }