readability-implicit-bool-conversion assumes preprocessor macros return int


Bugzilla Link	PR51635
Status	NEW
Importance	P normal
Reported by	Robert Ankeney (rrankene@gmail.com)
Reported on	2021-08-26 13:11:55 -0700
Last modified on	2021-08-27 16:36:05 -0700
Version	unspecified
Hardware	PC Linux
CC	alexfh@google.com, djasper@google.com, greg.harmon@joby.aero, klimek@google.com
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For the following code:
#define test() true

int main()
{
   bool bVal = (true == test());
   return static_cast<int>(bVal == true);
}

clang-tidy -checks=readability-implicit-bool-conversion returns:
1 warning generated.
/tmp/t.cpp:5:17: warning: implicit conversion bool -> 'int' [readability-
implicit-bool-conversion]
   bool bVal = (true == test());
                ^~~~
                1

It appears clang-tidy assumes test() returns an int. Running the code through
the preprocessor first, followed by clang-tidy produces no warnings.

Quuxplusone / LLVMBugzillaTest

readability-implicit-bool-conversion assumes preprocessor macros return int #50602