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[clang][Sema] Move computing best enum types to a separate function #120965

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Merged
merged 5 commits into from
Jan 17, 2025
Merged

[clang][Sema] Move computing best enum types to a separate function #120965

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ab8dcae
[clang][Sema] Move calculating enum width and type to a separate func…
kuilpd Dec 23, 2024
c41ddb9
Remove unnecessary arguments and adjust formatting
kuilpd Dec 23, 2024
f6c29bc
Rename the funtion
kuilpd Dec 24, 2024
c5f1dcf
Move the function to ASTContext
kuilpd Jan 14, 2025
6c08eff
Fix nits
kuilpd Jan 14, 2025
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5 changes: 5 additions & 0 deletions clang/include/clang/Sema/Sema.h
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Original file line number Diff line number Diff line change
Expand Up @@ -3987,6 +3987,11 @@ class Sema final : public SemaBase {
SourceLocation IdLoc, IdentifierInfo *Id,
const ParsedAttributesView &Attrs,
SourceLocation EqualLoc, Expr *Val);

bool ComputeBestEnumProperties(ASTContext &Context, bool isPacked,
unsigned NumNegativeBits,
unsigned NumPositiveBits, QualType &BestType,
QualType &BestPromotionType);
void ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
Decl *EnumDecl, ArrayRef<Decl *> Elements, Scope *S,
const ParsedAttributesView &Attr);
Expand Down
162 changes: 91 additions & 71 deletions clang/lib/Sema/SemaDecl.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -20008,6 +20008,90 @@ bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val));
}

bool Sema::ComputeBestEnumProperties(ASTContext &Context, bool isPacked,
unsigned NumNegativeBits,
unsigned NumPositiveBits,
QualType &BestType,
QualType &BestPromotionType) {
unsigned IntWidth = Context.getTargetInfo().getIntWidth();
unsigned CharWidth = Context.getTargetInfo().getCharWidth();
unsigned ShortWidth = Context.getTargetInfo().getShortWidth();
bool EnumTooLarge = false;
unsigned BestWidth;
if (NumNegativeBits) {
// If there is a negative value, figure out the smallest integer type (of
// int/long/longlong) that fits.
// If it's packed, check also if it fits a char or a short.
if (isPacked && NumNegativeBits <= CharWidth &&
NumPositiveBits < CharWidth) {
BestType = Context.SignedCharTy;
BestWidth = CharWidth;
} else if (isPacked && NumNegativeBits <= ShortWidth &&
NumPositiveBits < ShortWidth) {
BestType = Context.ShortTy;
BestWidth = ShortWidth;
} else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
BestType = Context.IntTy;
BestWidth = IntWidth;
} else {
BestWidth = Context.getTargetInfo().getLongWidth();

if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) {
BestType = Context.LongTy;
} else {
BestWidth = Context.getTargetInfo().getLongLongWidth();

if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
EnumTooLarge = true;
BestType = Context.LongLongTy;
}
}
BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType);
} else {
// 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 (isPacked && NumPositiveBits <= CharWidth) {
BestType = Context.UnsignedCharTy;
BestPromotionType = Context.IntTy;
BestWidth = CharWidth;
} else if (isPacked && NumPositiveBits <= ShortWidth) {
BestType = Context.UnsignedShortTy;
BestPromotionType = Context.IntTy;
BestWidth = ShortWidth;
} else if (NumPositiveBits <= IntWidth) {
BestType = Context.UnsignedIntTy;
BestWidth = IntWidth;
BestPromotionType =
(NumPositiveBits == BestWidth || !Context.getLangOpts().CPlusPlus)
? Context.UnsignedIntTy
: Context.IntTy;
} else if (NumPositiveBits <=
(BestWidth = Context.getTargetInfo().getLongWidth())) {
BestType = Context.UnsignedLongTy;
BestPromotionType =
(NumPositiveBits == BestWidth || !Context.getLangOpts().CPlusPlus)
? Context.UnsignedLongTy
: Context.LongTy;
} else {
BestWidth = Context.getTargetInfo().getLongLongWidth();
if (NumPositiveBits > BestWidth) {
// This can happen with bit-precise integer types, but those are not
// allowed as the type for an enumerator per C23 6.7.2.2p4 and p12.
// FIXME: GCC uses __int128_t and __uint128_t for cases that fit within
// a 128-bit integer, we should consider doing the same.
EnumTooLarge = true;
}
BestType = Context.UnsignedLongLongTy;
BestPromotionType =
(NumPositiveBits == BestWidth || !Context.getLangOpts().CPlusPlus)
? Context.UnsignedLongLongTy
: Context.LongLongTy;
}
}
return EnumTooLarge;
}

void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
Decl *EnumDeclX, ArrayRef<Decl *> Elements, Scope *S,
const ParsedAttributesView &Attrs) {
Expand All @@ -20030,10 +20114,6 @@ void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
return;
}

unsigned IntWidth = Context.getTargetInfo().getIntWidth();
unsigned CharWidth = Context.getTargetInfo().getCharWidth();
unsigned ShortWidth = Context.getTargetInfo().getShortWidth();

// Verify that all the values are okay, compute the size of the values, and
// reverse the list.
unsigned NumNegativeBits = 0;
Expand Down Expand Up @@ -20099,73 +20179,13 @@ void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
BestPromotionType = BestType;

BestWidth = Context.getIntWidth(BestType);
}
else if (NumNegativeBits) {
// If there is a negative value, figure out the smallest integer type (of
// int/long/longlong) that fits.
// If it's packed, check also if it fits a char or a short.
if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) {
BestType = Context.SignedCharTy;
BestWidth = CharWidth;
} else if (Packed && NumNegativeBits <= ShortWidth &&
NumPositiveBits < ShortWidth) {
BestType = Context.ShortTy;
BestWidth = ShortWidth;
} else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
BestType = Context.IntTy;
BestWidth = IntWidth;
} else {
BestWidth = Context.getTargetInfo().getLongWidth();

if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) {
BestType = Context.LongTy;
} else {
BestWidth = Context.getTargetInfo().getLongLongWidth();

if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
Diag(Enum->getLocation(), diag::ext_enum_too_large);
BestType = Context.LongLongTy;
}
}
BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType);
} else {
// 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;
BestPromotionType = Context.IntTy;
BestWidth = CharWidth;
} else if (Packed && NumPositiveBits <= ShortWidth) {
BestType = Context.UnsignedShortTy;
BestPromotionType = Context.IntTy;
BestWidth = ShortWidth;
} else if (NumPositiveBits <= IntWidth) {
BestType = Context.UnsignedIntTy;
BestWidth = IntWidth;
BestPromotionType
= (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
? Context.UnsignedIntTy : Context.IntTy;
} else if (NumPositiveBits <=
(BestWidth = Context.getTargetInfo().getLongWidth())) {
BestType = Context.UnsignedLongTy;
BestPromotionType
= (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
? Context.UnsignedLongTy : Context.LongTy;
} else {
BestWidth = Context.getTargetInfo().getLongLongWidth();
if (NumPositiveBits > BestWidth) {
// This can happen with bit-precise integer types, but those are not
// allowed as the type for an enumerator per C23 6.7.2.2p4 and p12.
// FIXME: GCC uses __int128_t and __uint128_t for cases that fit within
// a 128-bit integer, we should consider doing the same.
Diag(Enum->getLocation(), diag::ext_enum_too_large);
}
BestType = Context.UnsignedLongLongTy;
BestPromotionType
= (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
? Context.UnsignedLongLongTy : Context.LongLongTy;
}
bool EnumTooLarge =
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@Michael137 Michael137 Jan 2, 2025

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Suggested change
bool EnumTooLarge =
const bool EnumTooLarge =

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@Sirraide Sirraide Jan 13, 2025 •
edited
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Afaik we normally don’t do top-level const on local variables in Clang.

ComputeBestEnumProperties(Context, Packed, NumNegativeBits,
NumPositiveBits, BestType, BestPromotionType);
BestWidth = Context.getIntWidth(BestType);
if (EnumTooLarge)
Diag(Enum->getLocation(), diag::ext_enum_too_large);
}

// Loop over all of the enumerator constants, changing their types to match
Expand Down Expand Up @@ -20197,7 +20217,7 @@ void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
// int; or,
// - the enumerated type
NewTy = Context.IntTy;
NewWidth = IntWidth;
NewWidth = Context.getTargetInfo().getIntWidth();
NewSign = true;
} else if (ECD->getType() == BestType) {
// Already the right type!
Expand Down