Don't ship a full C++ demangler as part of libc++abi

src/cxa_demangle.cpp

Index: src/cxa_demangle.cpp
diff --git a/src/cxa_demangle.cpp b/src/cxa_demangle.cpp
index ba8225cfd2d5363ac95a06f479fe0f7b21f6a81b..f9971898d99dedfebfba4305c67f6270c2e91f6b 100644
--- a/src/cxa_demangle.cpp
+++ b/src/cxa_demangle.cpp
@@ -4598,6 +4598,16 @@ extern "C"
 char*
 __cxa_demangle(const char* mangled_name, char* buf, size_t* n, int* status)
 {
+  // @LOCALMOD-START
+  // The demangler is *huge* and only used in default_terminate_handler
+  // with a fallback to printing mangled names instead. pexe size
+  // matters a lot, so PNaCl only prints out mangled names when
+  // exceptions are uncaught.
+#ifdef __pnacl__
+  *status = 1;

[jvoung (off chromium), 2013/12/04 01:52:00]

The API says that status may be a null pointer (in which case the caller
wouldn't care about the status), so would be good to check first.

Also, it seems like the documented status values are 0, -1, -2, -3:
http://mentorembedded.github.io/cxx-abi/abi.html#demangler

Maybe do -1 and pretend that there is no memory for it?

[JF, 2013/12/04 02:10:25]

I fixed this and also moved the code down so it still does the checks below.

+  return 0;
+#else
+  // @LOCALMOD-END
     if (mangled_name == nullptr || (buf != nullptr && n == nullptr))
     {
         if (status)
@@ -4681,6 +4691,9 @@ __cxa_demangle(const char* mangled_name, char* buf, size_t* n, int* status)
     if (status)
         *status = internal_status;
     return buf;
+  // @LOCALMOD-START
+#endif // __pnacl__
+  // @LOCALMOD-END
 }
 
 }  // __cxxabiv1