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Merged
merged 3 commits into from
Oct 2, 2023
Merged

[Sema] Use underlying type of scoped enum for -Wformat diagnostics #67378

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a1c307d
[Sema] Use underlying type of scoped enum for -Wformat diagnostics
smeenai Sep 25, 2023
80245c8
Merge remote-tracking branch 'origin/main' into fixit-fix
smeenai Oct 2, 2023
a64efd7
Add release notes
smeenai Oct 2, 2023
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3 changes: 3 additions & 0 deletions clang/docs/ReleaseNotes.rst
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Expand Up @@ -213,6 +213,9 @@ Improvements to Clang's diagnostics
(`#54678: <https://github.com/llvm/llvm-project/issues/54678>`_).
- Clang now prints its 'note' diagnostic in cyan instead of black, to be more compatible
with terminals with dark background colors. This is also more consistent with GCC.
- The fix-it emitted by ``-Wformat`` for scoped enumerations now take the
enumeration's underlying type into account instead of suggesting a type just
based on the format string specifier being used.

Bug Fixes in This Version
-------------------------
Expand Down
25 changes: 12 additions & 13 deletions clang/lib/Sema/SemaChecking.cpp
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Expand Up @@ -11356,12 +11356,15 @@ CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
ImplicitMatch == ArgType::NoMatchTypeConfusion)
Match = ImplicitMatch;
assert(Match != ArgType::MatchPromotion);

// Look through unscoped enums to their underlying type.
bool IsEnum = false;
bool IsScopedEnum = false;
QualType IntendedTy = ExprTy;
if (auto EnumTy = ExprTy->getAs<EnumType>()) {
IntendedTy = EnumTy->getDecl()->getIntegerType();
if (EnumTy->isUnscopedEnumerationType()) {
ExprTy = EnumTy->getDecl()->getIntegerType();
ExprTy = IntendedTy;
// This controls whether we're talking about the underlying type or not,
// which we only want to do when it's an unscoped enum.
IsEnum = true;
Expand All @@ -11373,7 +11376,6 @@ CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
// %C in an Objective-C context prints a unichar, not a wchar_t.
// If the argument is an integer of some kind, believe the %C and suggest
// a cast instead of changing the conversion specifier.
QualType IntendedTy = ExprTy;
if (isObjCContext() &&
FS.getConversionSpecifier().getKind() == ConversionSpecifier::CArg) {
if (ExprTy->isIntegralOrUnscopedEnumerationType() &&
Expand Down Expand Up @@ -11409,8 +11411,10 @@ CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
std::tie(CastTy, CastTyName) = shouldNotPrintDirectly(S.Context, IntendedTy, E);
if (!CastTy.isNull()) {
// %zi/%zu and %td/%tu are OK to use for NSInteger/NSUInteger of type int
// (long in ASTContext). Only complain to pedants.
if ((CastTyName == "NSInteger" || CastTyName == "NSUInteger") &&
// (long in ASTContext). Only complain to pedants or when they're the
// underlying type of a scoped enum (which always needs a cast).
if (!IsScopedEnum &&
(CastTyName == "NSInteger" || CastTyName == "NSUInteger") &&
(AT.isSizeT() || AT.isPtrdiffT()) &&
AT.matchesType(S.Context, CastTy))
Match = ArgType::NoMatchPedantic;
Expand Down Expand Up @@ -11465,20 +11469,15 @@ CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
// should be printed as 'long' for 64-bit compatibility.)
// Rather than emitting a normal format/argument mismatch, we want to
// add a cast to the recommended type (and correct the format string
// if necessary).
// if necessary). We should also do so for scoped enumerations.
SmallString<16> CastBuf;
llvm::raw_svector_ostream CastFix(CastBuf);
CastFix << (S.LangOpts.CPlusPlus ? "static_cast<" : "(");
if (IsScopedEnum) {
CastFix << AT.getRepresentativeType(S.Context).getAsString(
S.Context.getPrintingPolicy());
} else {
IntendedTy.print(CastFix, S.Context.getPrintingPolicy());
}
IntendedTy.print(CastFix, S.Context.getPrintingPolicy());
CastFix << (S.LangOpts.CPlusPlus ? ">" : ")");

SmallVector<FixItHint,4> Hints;
if ((!AT.matchesType(S.Context, IntendedTy) && !IsScopedEnum) ||
if (AT.matchesType(S.Context, IntendedTy) != ArgType::Match ||
ShouldNotPrintDirectly)
Hints.push_back(FixItHint::CreateReplacement(SpecRange, os.str()));

Expand Down Expand Up @@ -11506,7 +11505,7 @@ CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
Hints.push_back(FixItHint::CreateInsertion(After, ")"));
}

if (ShouldNotPrintDirectly) {
if (ShouldNotPrintDirectly && !IsScopedEnum) {
// The expression has a type that should not be printed directly.
// We extract the name from the typedef because we don't want to show
// the underlying type in the diagnostic.
Expand Down
35 changes: 35 additions & 0 deletions clang/test/FixIt/format-darwin-enum-class.cpp
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@@ -0,0 +1,35 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -verify -Wformat %s
// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -fdiagnostics-parseable-fixits -Wformat %s 2>&1 | FileCheck %s

extern "C" int printf(const char * restrict, ...);

#if __LP64__
typedef long CFIndex;
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int CFIndex;
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif

enum class CFIndexEnum : CFIndex { One };
enum class NSIntegerEnum : NSInteger { Two };
enum class NSUIntegerEnum : NSUInteger { Three };

void f() {
printf("%d", CFIndexEnum::One); // expected-warning{{format specifies type 'int' but the argument has type 'CFIndexEnum'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:13}:"%ld"
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:16-[[@LINE-2]]:16}:"static_cast<long>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:32-[[@LINE-3]]:32}:")"

printf("%d", NSIntegerEnum::Two); // expected-warning{{format specifies type 'int' but the argument has type 'NSIntegerEnum'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:13}:"%ld"
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:16-[[@LINE-2]]:16}:"static_cast<long>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:34-[[@LINE-3]]:34}:")"

printf("%d", NSUIntegerEnum::Three); // expected-warning{{format specifies type 'int' but the argument has type 'NSUIntegerEnum'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:13}:"%lu"
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:16-[[@LINE-2]]:16}:"static_cast<unsigned long>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:37-[[@LINE-3]]:37}:")"
}
20 changes: 18 additions & 2 deletions clang/test/FixIt/format.cpp
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Expand Up @@ -12,21 +12,33 @@ struct S {
N::E Type;
};

using uint32_t = unsigned;
enum class FixedE : uint32_t { Two };

void a(N::E NEVal, S *SPtr, S &SRef) {
printf("%d", N::E::One); // expected-warning{{format specifies type 'int' but the argument has type 'N::E'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:16-[[@LINE-1]]:16}:"static_cast<int>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:25-[[@LINE-2]]:25}:")"

printf("%hd", N::E::One); // expected-warning{{format specifies type 'short' but the argument has type 'N::E'}}
// CHECK: "static_cast<short>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:14}:"%d"
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:17-[[@LINE-2]]:17}:"static_cast<int>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:26-[[@LINE-3]]:26}:")"

printf("%hu", N::E::One); // expected-warning{{format specifies type 'unsigned short' but the argument has type 'N::E'}}
// CHECK: "static_cast<unsigned short>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:14}:"%d"
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:17-[[@LINE-2]]:17}:"static_cast<int>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:26-[[@LINE-3]]:26}:")"

LOG("%d", N::E::One); // expected-warning{{format specifies type 'int' but the argument has type 'N::E'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:13-[[@LINE-1]]:13}:"static_cast<int>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:22-[[@LINE-2]]:22}:")"

LOG("%s", N::E::One); // expected-warning{{format specifies type 'char *' but the argument has type 'N::E'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:8-[[@LINE-1]]:10}:"%d"
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"static_cast<int>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:22-[[@LINE-3]]:22}:")"

printf("%d", NEVal); // expected-warning{{format specifies type 'int' but the argument has type 'N::E'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:16-[[@LINE-1]]:16}:"static_cast<int>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:21-[[@LINE-2]]:21}:")"
Expand Down Expand Up @@ -58,4 +70,8 @@ void a(N::E NEVal, S *SPtr, S &SRef) {
SRef.Type);
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:7-[[@LINE-1]]:7}:"static_cast<int>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:16-[[@LINE-2]]:16}:")"

printf("%u", FixedE::Two); //expected-warning{{format specifies type 'unsigned int' but the argument has type 'FixedE'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:16-[[@LINE-1]]:16}:"static_cast<uint32_t>("
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:27-[[@LINE-2]]:27}:")"
}