Tentatively apply https://reviews.llvm.org/D23921, to get rid of false

positive diagnostics from -Wvarargs about enum parameters, e.g.:

cddl/contrib/opensolaris/lib/libnvpair/libnvpair.c:388:15: error: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior
      [-Werror,-Wvarargs]
        va_start(ap, which);
                     ^
cddl/contrib/opensolaris/lib/libnvpair/libnvpair.c:382:66: note: parameter of type 'enum nvlist_prtctl_fmt' is declared here
nvlist_prtctl_dofmt(nvlist_prtctl_t pctl, enum nvlist_prtctl_fmt which, ...)
                                                                 ^
This commit is contained in:
dim 2016-08-28 19:28:00 +00:00
parent aeb74474a8
commit 57497b8693

View File

@ -3189,8 +3189,17 @@ bool Sema::SemaBuiltinVAStartImpl(CallExpr *TheCall) {
Diag(TheCall->getArg(1)->getLocStart(),
diag::warn_second_arg_of_va_start_not_last_named_param);
else if (IsCRegister || Type->isReferenceType() ||
Type->isPromotableIntegerType() ||
Type->isSpecificBuiltinType(BuiltinType::Float)) {
Type->isSpecificBuiltinType(BuiltinType::Float) || [=] {
// Promotable integers are UB, but enumerations need a bit of
// extra checking to see what their promotable type actually is.
if (!Type->isPromotableIntegerType())
return false;
if (!Type->isEnumeralType())
return true;
const EnumDecl *ED = Type->getAs<EnumType>()->getDecl();
return !(ED &&
Context.typesAreCompatible(ED->getPromotionType(), Type));
}()) {
unsigned Reason = 0;
if (Type->isReferenceType()) Reason = 1;
else if (IsCRegister) Reason = 2;