Don't set -fvisibility=hidden for iOS Debug.

build/config/BUILDCONFIG.gn

Index: build/config/BUILDCONFIG.gn
diff --git a/build/config/BUILDCONFIG.gn b/build/config/BUILDCONFIG.gn
index 54bf3722fa5c5c1197e790834d0154279a804dee..a90228fb54e8b356e10ad5ec43bc679e2b40204a 100644
--- a/build/config/BUILDCONFIG.gn
+++ b/build/config/BUILDCONFIG.gn
@@ -472,10 +472,13 @@ if (current_os == "winrt_81" || current_os == "winrt_81_phone" ||
   _native_compiler_configs += [ "//build/config/win:target_winrt" ]
 }
 if (is_posix) {
-  _native_compiler_configs += [
-    "//build/config/gcc:no_exceptions",
-    "//build/config/gcc:symbol_visibility_hidden",
-  ]
+  _native_compiler_configs += [ "//build/config/gcc:no_exceptions" ]
+
+  # XCTests require symbols to not be hidden.
+  if (!is_ios || is_release) {
+    _native_compiler_configs +=
+        [ "//build/config/gcc:symbol_visibility_hidden" ]

[brettw, 2015/12/12 23:53:18]

Let's do this: make a new config in build/config/gcc like:

config("default_symbol_visibility") {
  if (!is_posix || is_release) {
    configs = [ ":symbol_visibility_hidden" ]
  }
}

Then you can unconditionally reference the default symbol visibility from here.

Can you also write a better comment? I don't know what XCTests are or what this
might have to do with debug vs. release.

[baxley, 2015/12/14 18:46:52]

Done. Thanks for the detailed explanation.

+  }
 }
 
 if (is_android) {