diff --git a/change_notes/2024-12-17-fix-fp-824-a15-4-4 b/change_notes/2024-12-17-fix-fp-824-a15-4-4 index 0908c14ff..89ccf4981 100644 --- a/change_notes/2024-12-17-fix-fp-824-a15-4-4 +++ b/change_notes/2024-12-17-fix-fp-824-a15-4-4 @@ -1,2 +1,2 @@ - `A15-4-4` - `MissingNoExcept.ql`: - - Reduce false positives by not reporting on functions that have a noexcept specification with a complex expression. + - Reduce false positives by not reporting on functions that have a noexcept specification with a complex expression or call other such functions. diff --git a/cpp/autosar/src/rules/A15-4-4/MissingNoExcept.ql b/cpp/autosar/src/rules/A15-4-4/MissingNoExcept.ql index 2721b42af..33369e00a 100644 --- a/cpp/autosar/src/rules/A15-4-4/MissingNoExcept.ql +++ b/cpp/autosar/src/rules/A15-4-4/MissingNoExcept.ql @@ -19,6 +19,36 @@ import codingstandards.cpp.autosar import codingstandards.cpp.exceptions.ExceptionSpecifications import codingstandards.cpp.exceptions.ExceptionFlow +// These functions have a noexcept specification that could not be resolved +// to noexcept(true). So either, they are noexcept(false) functions which +// means, they can throw an exception OR they have an expression which +// could not be resolved to "true" or "false". Even in this case, lets +// be more conservative and assume they may thrown an exception. +class FunctionWithUnknownNoExcept extends Function { + FunctionWithUnknownNoExcept() { + // Exists a noexcept specification but not noexcept(true) + exists(this.getADeclarationEntry().getNoExceptExpr()) and + not isNoExceptTrue(this) + } +} + +// This predicate checks if a function can call to other functions +// that may have a noexcept specification which cannot be resolved to +// noexcept(true). +predicate mayCallThrowingFunctions(Function f) { + // Exists a call in this function + exists(Call fc | + fc.getEnclosingFunction() = f and + ( + // Either this call is to a function with an unknown noexcept OR + fc.getTarget() instanceof FunctionWithUnknownNoExcept + or + // That function can further have calls to unknown noexcept functions. + mayCallThrowingFunctions(fc.getTarget()) + ) + ) +} + from Function f where not isExcluded(f, Exceptions1Package::missingNoExceptQuery()) and @@ -31,6 +61,9 @@ where // Not having a noexcept specification that // could not be computed as true or false above. not exists(f.getADeclarationEntry().getNoExceptExpr()) and + // Not calling function(s) which have a noexcept specification that + // could not be computed as true. + not mayCallThrowingFunctions(f) and // Not compiler generated not f.isCompilerGenerated() and // The function is defined in this database