Create a new 'flag_enum' attribute.
This attribute serves as a hint to improve warnings about the ranges of
enumerators used as flag types. It currently has no working C++ implementation
due to different semantics for enums in C++. For more explanation, see the docs
and testcases.
Reviewed by Aaron Ballman.
llvm-svn: 222906
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 14f7092..78e33c3 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -687,26 +687,39 @@
}
}
+typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> EnumValsTy;
+
/// Returns true if we should emit a diagnostic about this case expression not
/// being a part of the enum used in the switch controlling expression.
-static bool ShouldDiagnoseSwitchCaseNotInEnum(const ASTContext &Ctx,
+static bool ShouldDiagnoseSwitchCaseNotInEnum(const Sema &S,
const EnumDecl *ED,
- const Expr *CaseExpr) {
- // Don't warn if the 'case' expression refers to a static const variable of
- // the enum type.
- CaseExpr = CaseExpr->IgnoreParenImpCasts();
- if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CaseExpr)) {
+ const Expr *CaseExpr,
+ EnumValsTy::iterator &EI,
+ EnumValsTy::iterator &EIEnd,
+ const llvm::APSInt &Val) {
+ bool FlagType = ED->hasAttr<FlagEnumAttr>();
+
+ if (const DeclRefExpr *DRE =
+ dyn_cast<DeclRefExpr>(CaseExpr->IgnoreParenImpCasts())) {
if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
- if (!VD->hasGlobalStorage())
- return true;
QualType VarType = VD->getType();
- if (!VarType.isConstQualified())
- return true;
- QualType EnumType = Ctx.getTypeDeclType(ED);
- if (Ctx.hasSameUnqualifiedType(EnumType, VarType))
+ QualType EnumType = S.Context.getTypeDeclType(ED);
+ if (VD->hasGlobalStorage() && VarType.isConstQualified() &&
+ S.Context.hasSameUnqualifiedType(EnumType, VarType))
return false;
}
}
+
+ if (FlagType) {
+ return !S.IsValueInFlagEnum(ED, Val, false);
+ } else {
+ while (EI != EIEnd && EI->first < Val)
+ EI++;
+
+ if (EI != EIEnd && EI->first == Val)
+ return false;
+ }
+
return true;
}
@@ -1045,8 +1058,6 @@
// If switch has default case, then ignore it.
if (!CaseListIsErroneous && !HasConstantCond && ET) {
const EnumDecl *ED = ET->getDecl();
- typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64>
- EnumValsTy;
EnumValsTy EnumVals;
// Gather all enum values, set their type and sort them,
@@ -1057,57 +1068,48 @@
EnumVals.push_back(std::make_pair(Val, EDI));
}
std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
- EnumValsTy::iterator EIend =
+ auto EI = EnumVals.begin(), EIEnd =
std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
// See which case values aren't in enum.
- EnumValsTy::const_iterator EI = EnumVals.begin();
for (CaseValsTy::const_iterator CI = CaseVals.begin();
- CI != CaseVals.end(); CI++) {
- while (EI != EIend && EI->first < CI->first)
- EI++;
- if (EI == EIend || EI->first > CI->first) {
- Expr *CaseExpr = CI->second->getLHS();
- if (ShouldDiagnoseSwitchCaseNotInEnum(Context, ED, CaseExpr))
- Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
- << CondTypeBeforePromotion;
- }
+ CI != CaseVals.end(); CI++) {
+ Expr *CaseExpr = CI->second->getLHS();
+ if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
+ CI->first))
+ Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
+ << CondTypeBeforePromotion;
}
+
// See which of case ranges aren't in enum
EI = EnumVals.begin();
for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
- RI != CaseRanges.end() && EI != EIend; RI++) {
- while (EI != EIend && EI->first < RI->first)
- EI++;
-
- if (EI == EIend || EI->first != RI->first) {
- Expr *CaseExpr = RI->second->getLHS();
- if (ShouldDiagnoseSwitchCaseNotInEnum(Context, ED, CaseExpr))
- Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
- << CondTypeBeforePromotion;
- }
+ RI != CaseRanges.end(); RI++) {
+ Expr *CaseExpr = RI->second->getLHS();
+ if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
+ RI->first))
+ Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
+ << CondTypeBeforePromotion;
llvm::APSInt Hi =
RI->second->getRHS()->EvaluateKnownConstInt(Context);
AdjustAPSInt(Hi, CondWidth, CondIsSigned);
- while (EI != EIend && EI->first < Hi)
- EI++;
- if (EI == EIend || EI->first != Hi) {
- Expr *CaseExpr = RI->second->getRHS();
- if (ShouldDiagnoseSwitchCaseNotInEnum(Context, ED, CaseExpr))
- Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
- << CondTypeBeforePromotion;
- }
+
+ CaseExpr = RI->second->getRHS();
+ if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
+ Hi))
+ Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
+ << CondTypeBeforePromotion;
}
// Check which enum vals aren't in switch
- CaseValsTy::const_iterator CI = CaseVals.begin();
- CaseRangesTy::const_iterator RI = CaseRanges.begin();
+ auto CI = CaseVals.begin();
+ auto RI = CaseRanges.begin();
bool hasCasesNotInSwitch = false;
SmallVector<DeclarationName,8> UnhandledNames;
- for (EI = EnumVals.begin(); EI != EIend; EI++){
+ for (EI = EnumVals.begin(); EI != EIEnd; EI++){
// Drop unneeded case values
while (CI != CaseVals.end() && CI->first < EI->first)
CI++;
@@ -1194,30 +1196,37 @@
llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context);
AdjustAPSInt(RhsVal, DstWidth, DstIsSigned);
const EnumDecl *ED = ET->getDecl();
- typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl *>, 64>
- EnumValsTy;
- EnumValsTy EnumVals;
- // Gather all enum values, set their type and sort them,
- // allowing easier comparison with rhs constant.
- for (auto *EDI : ED->enumerators()) {
- llvm::APSInt Val = EDI->getInitVal();
- AdjustAPSInt(Val, DstWidth, DstIsSigned);
- EnumVals.push_back(std::make_pair(Val, EDI));
- }
- if (EnumVals.empty())
- return;
- std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
- EnumValsTy::iterator EIend =
- std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
-
- // See which values aren't in the enum.
- EnumValsTy::const_iterator EI = EnumVals.begin();
- while (EI != EIend && EI->first < RhsVal)
- EI++;
- if (EI == EIend || EI->first != RhsVal) {
- Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
+ if (ED->hasAttr<FlagEnumAttr>()) {
+ if (!IsValueInFlagEnum(ED, RhsVal, true))
+ Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
<< DstType.getUnqualifiedType();
+ } else {
+ typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl *>, 64>
+ EnumValsTy;
+ EnumValsTy EnumVals;
+
+ // Gather all enum values, set their type and sort them,
+ // allowing easier comparison with rhs constant.
+ for (auto *EDI : ED->enumerators()) {
+ llvm::APSInt Val = EDI->getInitVal();
+ AdjustAPSInt(Val, DstWidth, DstIsSigned);
+ EnumVals.push_back(std::make_pair(Val, EDI));
+ }
+ if (EnumVals.empty())
+ return;
+ std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
+ EnumValsTy::iterator EIend =
+ std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
+
+ // See which values aren't in the enum.
+ EnumValsTy::const_iterator EI = EnumVals.begin();
+ while (EI != EIend && EI->first < RhsVal)
+ EI++;
+ if (EI == EIend || EI->first != RhsVal) {
+ Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
+ << DstType.getUnqualifiedType();
+ }
}
}
}