1850505 - Avoid -ftrivial-auto-var-init overhead in mozHunspellFileMgrHost::GetLine

Status: RESOLVED FIXED

(Firefox Build System :: General, task)

Description

[[:sergesanspaille]]

mozHunspellFileMgrHost::GetLine is defined as followed:

 bool mozHunspellFileMgrHost::GetLine(std::string& aResult) {
  nsAutoCString line;
  auto res = ReadLine(line);
  if (res.isErr()) {
    return false;
  }

  aResult.assign(line.BeginReading(), line.Length());
  return true;
}

nsAutoCString iteracts poorly with -ftrivial-auto-var-init as it always initializes the internal buffer. In that particular case line is used a temporary container, we could avoid both the initialization and the copy by directly writing to a std::string

Comment 1

[[:sergesanspaille]]

Attachment: Bug 1850505 - Avoid extra copy in mozHunspellFileMgrHost::GetLine r=emilio

This also positively impacts -ftrivial-auto-var-init as it gets rid of
the nsAutoCString buffer initialization.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cf7a219d11da
Avoid extra copy in mozHunspellFileMgrHost::GetLine r=emilio

Comment 3

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/cf7a219d11da