We have a bunch of uses of std::wstring in the IPC code and in code that needs to implement IPC-imposed signatures: https://searchfox.org/mozilla-central/search?q=std%3A%3Awstring&case=false&regexp=false&path= std::wstring is not portable. It is UTF-32 on Linux and UTF-16 on Windows. We should replace the usage of std::wstring with one of: * nsACString holding UTF-8 * nsAString holding UTF-16 * std::string holding UTF-8 * std::u16string holding UTF-16 It's unclear to me which of UTF-8 or UTF-16 would result in fewer conversions and it's unclear to me if using XPCOM strings would be hard. At least std::string or std::u16string would keep code structurally the same as before.

Some of this might be dead code, or nearly dead — I have patches in the pipeline to completely remove file_util and also remove the names from shared_memory, and I suspect that parts of the string_util and command_line stuff might be unused.