Implement promotion for enumeration types.
WHAT!?!
It turns out that Type::isPromotableIntegerType() was not considering
enumeration types to be promotable, so we would never do the
promotion despite having properly computed the promotion type when the
enum was defined. Various operations on values of enum type just
"worked" because we could still compute the integer rank of an enum
type; the oddity, however, is that operations such as "add an enum and
an unsigned" would often have an enum result type (!). The bug
actually showed up as a spurious -Wformat diagnostic
(<rdar://problem/7595366>), but in theory it could cause miscompiles.
In this commit:
- Enum types with a promotion type of "int" or "unsigned int" are
promotable.
- Tweaked the computation of promotable types for enums
- For all of the ABIs, treat enum types the same way as their
underlying types (*not* their promotion types) for argument passing
and return values
- Extend the ABI tester with support for enumeration types
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95117 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index edfb580..504ffc5 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -720,6 +720,19 @@
default:
return false;
}
+
+ // Enumerated types are promotable to their compatible integer types
+ // (C99 6.3.1.1) a.k.a. its underlying type (C++ [conv.prom]p2).
+ if (const EnumType *ET = getAs<EnumType>()){
+ if (this->isDependentType() || ET->getDecl()->getPromotionType().isNull())
+ return false;
+
+ const BuiltinType *BT
+ = ET->getDecl()->getPromotionType()->getAs<BuiltinType>();
+ return BT->getKind() == BuiltinType::Int
+ || BT->getKind() == BuiltinType::UInt;
+ }
+
return false;
}
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index 07f116a..6f650fc 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -271,6 +271,10 @@
if (CodeGenFunction::hasAggregateLLVMType(Ty)) {
return ABIArgInfo::getIndirect(0);
} else {
+ // Treat an enum type as its underlying type.
+ if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+ Ty = EnumTy->getDecl()->getIntegerType();
+
return (Ty->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
}
@@ -465,6 +469,10 @@
return ABIArgInfo::getIndirect(0);
} else {
+ // Treat an enum type as its underlying type.
+ if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
+ RetTy = EnumTy->getDecl()->getIntegerType();
+
return (RetTy->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
}
@@ -511,6 +519,9 @@
return ABIArgInfo::getIndirect(getIndirectArgumentAlignment(Ty, Context));
} else {
+ if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+ Ty = EnumTy->getDecl()->getIntegerType();
+
return (Ty->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
}
@@ -935,6 +946,11 @@
if (CoerceTo == llvm::Type::getInt64Ty(CoerceTo->getContext())) {
// Integer and pointer types will end up in a general purpose
// register.
+
+ // Treat an enum type as its underlying type.
+ if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+ Ty = EnumTy->getDecl()->getIntegerType();
+
if (Ty->isIntegralType() || Ty->hasPointerRepresentation())
return (Ty->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
@@ -956,9 +972,14 @@
ASTContext &Context) const {
// If this is a scalar LLVM value then assume LLVM will pass it in the right
// place naturally.
- if (!CodeGenFunction::hasAggregateLLVMType(Ty))
+ if (!CodeGenFunction::hasAggregateLLVMType(Ty)) {
+ // Treat an enum type as its underlying type.
+ if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+ Ty = EnumTy->getDecl()->getIntegerType();
+
return (Ty->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
+ }
bool ByVal = !isRecordWithNonTrivialDestructorOrCopyConstructor(Ty);
@@ -1534,9 +1555,14 @@
ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty,
ASTContext &Context,
llvm::LLVMContext &VMContext) const {
- if (!CodeGenFunction::hasAggregateLLVMType(Ty))
+ if (!CodeGenFunction::hasAggregateLLVMType(Ty)) {
+ // Treat an enum type as its underlying type.
+ if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+ Ty = EnumTy->getDecl()->getIntegerType();
+
return (Ty->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
+ }
// Ignore empty records.
if (isEmptyRecord(Context, Ty, true))
@@ -1652,9 +1678,14 @@
if (RetTy->isVoidType())
return ABIArgInfo::getIgnore();
- if (!CodeGenFunction::hasAggregateLLVMType(RetTy))
+ if (!CodeGenFunction::hasAggregateLLVMType(RetTy)) {
+ // Treat an enum type as its underlying type.
+ if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
+ RetTy = EnumTy->getDecl()->getIntegerType();
+
return (RetTy->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
+ }
// Are we following APCS?
if (getABIKind() == APCS) {
@@ -1737,6 +1768,10 @@
} else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) {
return ABIArgInfo::getIndirect(0);
} else {
+ // Treat an enum type as its underlying type.
+ if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
+ RetTy = EnumTy->getDecl()->getIntegerType();
+
return (RetTy->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
}
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 8f756da..c604f6a 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -5971,8 +5971,8 @@
}
BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType);
} else {
- // If there is no negative value, figure out which of uint, ulong, ulonglong
- // fits.
+ // If there is no negative value, figure out the smallest type that fits
+ // all of the enumerator values.
// If it's packed, check also if it fits a char or a short.
if (Packed && NumPositiveBits <= CharWidth) {
BestType = Context.UnsignedCharTy;
@@ -5985,30 +5985,26 @@
} else if (NumPositiveBits <= IntWidth) {
BestType = Context.UnsignedIntTy;
BestWidth = IntWidth;
- BestPromotionType = (NumPositiveBits == BestWidth
- ? Context.UnsignedIntTy : Context.IntTy);
+ BestPromotionType
+ = (NumPositiveBits == BestWidth || !getLangOptions().CPlusPlus)
+ ? Context.UnsignedIntTy : Context.IntTy;
} else if (NumPositiveBits <=
(BestWidth = Context.Target.getLongWidth())) {
BestType = Context.UnsignedLongTy;
- BestPromotionType = (NumPositiveBits == BestWidth
- ? Context.UnsignedLongTy : Context.LongTy);
+ BestPromotionType
+ = (NumPositiveBits == BestWidth || !getLangOptions().CPlusPlus)
+ ? Context.UnsignedLongTy : Context.LongTy;
} else {
BestWidth = Context.Target.getLongLongWidth();
assert(NumPositiveBits <= BestWidth &&
"How could an initializer get larger than ULL?");
BestType = Context.UnsignedLongLongTy;
- BestPromotionType = (NumPositiveBits == BestWidth
- ? Context.UnsignedLongLongTy : Context.LongLongTy);
+ BestPromotionType
+ = (NumPositiveBits == BestWidth || !getLangOptions().CPlusPlus)
+ ? Context.UnsignedLongLongTy : Context.LongLongTy;
}
}
- // If we're in C and the promotion type is larger than an int, just
- // use the underlying type, which is generally the unsigned integer
- // type of the same rank as the promotion type. This is how the gcc
- // extension works.
- if (!getLangOptions().CPlusPlus && BestPromotionType != Context.IntTy)
- BestPromotionType = BestType;
-
// Loop over all of the enumerator constants, changing their types to match
// the type of the enum if needed.
for (unsigned i = 0; i != NumElements; ++i) {
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 033cbfd..d1d9bda 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -768,7 +768,8 @@
// int can represent all the values of the source type; otherwise,
// the source rvalue can be converted to an rvalue of type unsigned
// int (C++ 4.5p1).
- if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) {
+ if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
+ !FromType->isEnumeralType()) {
if (// We can promote any signed, promotable integer type to an int
(FromType->isSignedIntegerType() ||
// We can promote any unsigned integer type whose size is