[IMPALA-9761] Fix GCC 7 compilation issue: Ambiguous else warning with gtest macros

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Impala 4.0.0
• Fix Version/s: Impala 4.0.0
• Component/s: Backend
• Epic Link: GCC7_newabi_upgrade
• Target Version: Impala 4.0.0
• Epic Color: ghx-label-13
• Assignee: Joe McDonnell
• Reporter: Joe McDonnell
• Created: 19/May/20 04:53
• Updated: 29/May/20 04:26
• Resolved: 29/May/20 04:26

Description

Google test uses a macro to avoid a GCC warning about dangling else conditions. It suppresses a warning for code like:

if (foo) DCHECK(condition);

https://github.com/google/googletest/issues/1119

GCC 7 added new warnings and this macro no longer works. The solution is to either disable the new warning or use braces. Since using braces is easy, we should fix this by adding appropriate braces.