Problematic Warnings Suppressed

SYMPTOMS

Some compiler warnings occur when you build without BullseyeCoverage, but those warnings do not occur when BullseyeCoverage is enabled.

CAUSE

The BullseyeCoverage instrumentation introduces some complexity that could cause a compiler to issue an improper warning that does not occur without the instrumentation. BullseyeCoverage suppresses these warnings in order to avoid introducing new warnings (which may be treated as errors). Where possible, BullseyeCoverage only suppresses the specific problematic warnings. The warnings may include, but are not limited to, the issues listed below.

A function lacks a return statement.
A variable is not initialized before use.
A function intended for inline expansion was not expanded.
An exception is thrown from a function that is declared to not throw exceptions.
An inline function references data having internal linkage.
Unreachable code.
Improper line endings.
An unreferenced inline function was removed.
Implicit conversions.
Comparisons that always evaluate to true or false.
The compiler added padding to the end of a struct.
Raw buffer access.
One Definition Rule violation.
An if-else has identical branches.
Use of integer values where boolean values are expected.
An object with internal linkage is referenced from an inline function with external linkage.
Comparison operations between bool and int.
Switch statement has redundant default label.
Not all control paths return a value.

RESOLUTION

To check for compiler warnings, build with BullseyeCoverage disabled.

MORE INFORMATION

BullseyeCoverage uses source code instrumentation, which introduces additional complexity to the compiler. The criteria compilers use to decide whether to issue warnings may depend upon the result of code generation and optimization, which are affected by the code complexity. For example, the additional complexity may cause a compiler to fail to determine whether a certain path through the code is possible.

Updated: 16 Oct 2023