[Chromecast] Include all stdlibc++/libgcc symbols in cast_shell.

chromecast/chromecast.gyp

Index: chromecast/chromecast.gyp
diff --git a/chromecast/chromecast.gyp b/chromecast/chromecast.gyp
index 87988e61b93956849475ab4e956a98fb3ae30a67..38f734eb6e54ec3fa93f73d93900fe369633b721 100644
--- a/chromecast/chromecast.gyp
+++ b/chromecast/chromecast.gyp
@@ -76,6 +76,21 @@
         ],
       },
     },
+    # Applies linker flags to include whole libstdc++/libgcc and export them.
+    {
+      'target_name': 'cast_shlib_consumer_ldflags',

[bcf, 2015/11/25 19:31:23]

This is a target any executable which uses libcast* shlibs should depend on.

I assume we'd accomplish the same thing in gn using a config, but how can we add
ldflags to the end of link line (this is important)?

gn provides `libs`, but it prepends to each option: "Expands to the list of
system libraries to link to. Each will be prefixed by the "lib_prefix".". For
example "foo" will become "-lfoo"

https://chromium.googlesource.com/chromium/src/+/master/tools/gn/docs/referen...

+      'type': '<(component)',
+      'link_settings': {
+        'ldflags': ['-Wl,--export-dynamic'],
+        'libraries': [
+          '-Wl,--allow-multiple-definition',
+          '-Wl,--whole-archive',
+          '-l:libstdc++.a',
+          '-l:libgcc.a',
+          '-Wl,--no-whole-archive',
+        ],
+      },
+    },
     {
       'target_name': 'cast_base',
       'type': '<(component)',
@@ -775,6 +790,7 @@
           'type': 'executable',
           'dependencies': [
             'cast_shell_core',
+            'cast_shlib_consumer_ldflags',

[wzhong, 2015/11/25 20:46:26]

This only covers cast_shell.

How about other exec such as update_engine and unittests?

Why not just change chromium/src/build/common.gypi, where we already have
-static-libstdc++ and -static-libgcc?

           ],
           'sources': [
             'app/cast_main.cc',