1549852 - [Automated review] Coverity or clang-format thinks ifdefs always go one way

Status: RESOLVED WONTFIX

(Developer Infrastructure :: Source Code Analysis, defect)

Description

[:Gijs (he/him)]

Phabricator URL: https://phabricator.services.mozilla.com/D29892#inline-175786

Execution cannot reach the expression "xpc::IsInAutomation()" inside this statement: "if (allowSingleProcessOutsi...".

Code in question:

#if defined(MOZILLA_OFFICIAL) && MOZ_BUILD_APP_IS_BROWSER
  bool allowSingleProcessOutsideAutomation = false;
#else
  bool allowSingleProcessOutsideAutomation = true;
#endif

  int status = kE10sEnabledByDefault;
  if (allowSingleProcessOutsideAutomation || xpc::IsInAutomation()) {

It is late and I am not clever about C++, but given I just typed up a giant comment at bug 1548941 comment 8 about what happens when we do reach this expression in the valgrind test, I beg to differ.

Comment 1

[Andi [:andi]]

Unfortunately we don't have a solution for this since the analysis is performed on the AST, so at the AST level we don't have information on code that was discarding during the build time.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The priority flag is not set for this bug.
:sylvestre, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 3

[Sylvestre Ledru [:Sylvestre]]

Yeah, not much we can do here...
But one could argue that we could use the #if defined(MOZILLA_OFFICIAL) && MOZ_BUILD_APP_IS_BROWSER also on the other part of the code to make it obvious to the tools and humans that it won't be executed in the other cases.

This is a limitation of tools on which we are based and it would be pretty hard to fix.