[Sema] Diagnose tautological comparison with type's min/max values

Summary:
Currently, clang only diagnoses completely out-of-range comparisons (e.g. `char` and constant `300`),
and comparisons of unsigned and `0`. But gcc also does diagnose the comparisons with the
`std::numeric_limits<>::max()` / `std::numeric_limits<>::min()` so to speak

Finally Fixes https://bugs.llvm.org/show_bug.cgi?id=34147
Continuation of https://reviews.llvm.org/D37565

Reviewers: rjmccall, rsmith, aaron.ballman

Reviewed By: rsmith

Subscribers: rtrieu, jroelofs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D38101

llvm-svn: 315614
This commit is contained in:
Roman Lebedev 2017-10-12 20:16:51 +00:00
parent 060cb43721
commit bd1fc22043
7 changed files with 1026 additions and 292 deletions

View File

@ -78,6 +78,10 @@ Improvements to Clang's diagnostics
when the signed integer is coerced to an unsigned type for the comparison.
``-Wsign-compare`` was adjusted not to warn in this case.
- ``-Wtautological-constant-compare`` is a new warning that warns on
tautological comparisons between integer variable of the type ``T`` and the
largest/smallest possible integer constant of that same type.
- ``-Wnull-pointer-arithmetic`` now warns about performing pointer arithmetic
on a null pointer. Such pointer arithmetic has an undefined behavior if the
offset is nonzero. It also now warns about arithmetic on a null pointer

View File

@ -432,13 +432,15 @@ def StrncatSize : DiagGroup<"strncat-size">;
def TautologicalUnsignedZeroCompare : DiagGroup<"tautological-unsigned-zero-compare">;
def TautologicalUnsignedEnumZeroCompare : DiagGroup<"tautological-unsigned-enum-zero-compare">;
def TautologicalOutOfRangeCompare : DiagGroup<"tautological-constant-out-of-range-compare">;
def TautologicalConstantCompare : DiagGroup<"tautological-constant-compare",
[TautologicalUnsignedZeroCompare,
TautologicalUnsignedEnumZeroCompare,
TautologicalOutOfRangeCompare]>;
def TautologicalPointerCompare : DiagGroup<"tautological-pointer-compare">;
def TautologicalOverlapCompare : DiagGroup<"tautological-overlap-compare">;
def TautologicalUndefinedCompare : DiagGroup<"tautological-undefined-compare">;
def TautologicalCompare : DiagGroup<"tautological-compare",
[TautologicalUnsignedZeroCompare,
TautologicalUnsignedEnumZeroCompare,
TautologicalOutOfRangeCompare,
[TautologicalConstantCompare,
TautologicalPointerCompare,
TautologicalOverlapCompare,
TautologicalUndefinedCompare]>;

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@ -5938,18 +5938,18 @@ def note_typecheck_assign_const : Note<
"member function %q1 is declared const here|"
"%select{|nested }1data member %2 declared const here}0">;
def warn_lunsigned_always_true_comparison : Warning<
"comparison of unsigned expression %0 is always %select{false|true}1">,
def warn_unsigned_always_true_comparison : Warning<
"comparison of %select{%3|unsigned expression}0 %2 "
"%select{unsigned expression|%3}0 is always %select{false|true}4">,
InGroup<TautologicalUnsignedZeroCompare>;
def warn_runsigned_always_true_comparison : Warning<
"comparison of %0 unsigned expression is always %select{false|true}1">,
InGroup<TautologicalUnsignedZeroCompare>;
def warn_lunsigned_enum_always_true_comparison : Warning<
"comparison of unsigned enum expression %0 is always %select{false|true}1">,
InGroup<TautologicalUnsignedEnumZeroCompare>;
def warn_runsigned_enum_always_true_comparison : Warning<
"comparison of %0 unsigned enum expression is always %select{false|true}1">,
def warn_unsigned_enum_always_true_comparison : Warning<
"comparison of %select{%3|unsigned enum expression}0 %2 "
"%select{unsigned enum expression|%3}0 is always %select{false|true}4">,
InGroup<TautologicalUnsignedEnumZeroCompare>;
def warn_tautological_constant_compare : Warning<
"comparison %select{%3|%1}0 %2 "
"%select{%1|%3}0 is always %select{false|true}4">,
InGroup<TautologicalConstantCompare>;
def warn_mixed_sign_comparison : Warning<
"comparison of integers of different signs: %0 and %1">,

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@ -8553,19 +8553,71 @@ bool IsSameFloatAfterCast(const APValue &value,
void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC);
bool IsZero(Sema &S, Expr *E) {
bool IsEnumConstOrFromMacro(Sema &S, Expr *E) {
// Suppress cases where we are comparing against an enum constant.
if (const DeclRefExpr *DR =
dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
if (isa<EnumConstantDecl>(DR->getDecl()))
return false;
return true;
// Suppress cases where the '0' value is expanded from a macro.
if (E->getLocStart().isMacroID())
return false;
return true;
llvm::APSInt Value;
return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
return false;
}
bool isNonBooleanIntegerValue(Expr *E) {
return !E->isKnownToHaveBooleanValue() && E->getType()->isIntegerType();
}
bool isNonBooleanUnsignedValue(Expr *E) {
// We are checking that the expression is not known to have boolean value,
// is an integer type; and is either unsigned after implicit casts,
// or was unsigned before implicit casts.
return isNonBooleanIntegerValue(E) &&
(!E->getType()->isSignedIntegerType() ||
!E->IgnoreParenImpCasts()->getType()->isSignedIntegerType());
}
enum class LimitType {
Max, // e.g. 32767 for short
Min // e.g. -32768 for short
};
/// Checks whether Expr 'Constant' may be the
/// std::numeric_limits<>::max() or std::numeric_limits<>::min()
/// of the Expr 'Other'. If true, then returns the limit type (min or max).
/// The Value is the evaluation of Constant
llvm::Optional<LimitType> IsTypeLimit(Sema &S, Expr *Constant, Expr *Other,
const llvm::APSInt &Value) {
if (IsEnumConstOrFromMacro(S, Constant))
return llvm::Optional<LimitType>();
if (isNonBooleanUnsignedValue(Other) && Value == 0)
return LimitType::Min;
// TODO: Investigate using GetExprRange() to get tighter bounds
// on the bit ranges.
QualType OtherT = Other->IgnoreParenImpCasts()->getType();
if (const auto *AT = OtherT->getAs<AtomicType>())
OtherT = AT->getValueType();
IntRange OtherRange = IntRange::forValueOfType(S.Context, OtherT);
if (llvm::APSInt::isSameValue(
llvm::APSInt::getMaxValue(OtherRange.Width,
OtherT->isUnsignedIntegerType()),
Value))
return LimitType::Max;
if (llvm::APSInt::isSameValue(
llvm::APSInt::getMinValue(OtherRange.Width,
OtherT->isUnsignedIntegerType()),
Value))
return LimitType::Min;
return llvm::Optional<LimitType>();
}
bool HasEnumType(Expr *E) {
@ -8580,63 +8632,59 @@ bool HasEnumType(Expr *E) {
return E->getType()->isEnumeralType();
}
bool isNonBooleanUnsignedValue(Expr *E) {
// We are checking that the expression is not known to have boolean value,
// is an integer type; and is either unsigned after implicit casts,
// or was unsigned before implicit casts.
return !E->isKnownToHaveBooleanValue() && E->getType()->isIntegerType() &&
(!E->getType()->isSignedIntegerType() ||
!E->IgnoreParenImpCasts()->getType()->isSignedIntegerType());
}
bool CheckTautologicalComparisonWithZero(Sema &S, BinaryOperator *E) {
// Disable warning in template instantiations.
if (S.inTemplateInstantiation())
bool CheckTautologicalComparison(Sema &S, BinaryOperator *E, Expr *Constant,
Expr *Other, const llvm::APSInt &Value,
bool RhsConstant) {
// Disable warning in template instantiations
// and only analyze <, >, <= and >= operations.
if (S.inTemplateInstantiation() || !E->isRelationalOp())
return false;
// bool values are handled by DiagnoseOutOfRangeComparison().
BinaryOperatorKind Op = E->getOpcode();
if (E->isValueDependent())
QualType OType = Other->IgnoreParenImpCasts()->getType();
llvm::Optional<LimitType> ValueType; // Which limit (min/max) is the constant?
if (!(isNonBooleanIntegerValue(Other) &&
(ValueType = IsTypeLimit(S, Constant, Other, Value))))
return false;
Expr *LHS = E->getLHS();
Expr *RHS = E->getRHS();
bool ConstIsLowerBound = (Op == BO_LT || Op == BO_LE) ^ RhsConstant;
bool ResultWhenConstEqualsOther = (Op == BO_LE || Op == BO_GE);
bool ResultWhenConstNeOther = ConstIsLowerBound ^ ValueType == LimitType::Max;
if (ResultWhenConstEqualsOther != ResultWhenConstNeOther)
return false; // The comparison is not tautological.
bool Match = true;
const bool Result = ResultWhenConstEqualsOther;
if (Op == BO_LT && isNonBooleanUnsignedValue(LHS) && IsZero(S, RHS)) {
S.Diag(E->getOperatorLoc(),
HasEnumType(LHS) ? diag::warn_lunsigned_enum_always_true_comparison
: diag::warn_lunsigned_always_true_comparison)
<< "< 0" << false << LHS->getSourceRange() << RHS->getSourceRange();
} else if (Op == BO_GE && isNonBooleanUnsignedValue(LHS) && IsZero(S, RHS)) {
S.Diag(E->getOperatorLoc(),
HasEnumType(LHS) ? diag::warn_lunsigned_enum_always_true_comparison
: diag::warn_lunsigned_always_true_comparison)
<< ">= 0" << true << LHS->getSourceRange() << RHS->getSourceRange();
} else if (Op == BO_GT && isNonBooleanUnsignedValue(RHS) && IsZero(S, LHS)) {
S.Diag(E->getOperatorLoc(),
HasEnumType(RHS) ? diag::warn_runsigned_enum_always_true_comparison
: diag::warn_runsigned_always_true_comparison)
<< "0 >" << false << LHS->getSourceRange() << RHS->getSourceRange();
} else if (Op == BO_LE && isNonBooleanUnsignedValue(RHS) && IsZero(S, LHS)) {
S.Diag(E->getOperatorLoc(),
HasEnumType(RHS) ? diag::warn_runsigned_enum_always_true_comparison
: diag::warn_runsigned_always_true_comparison)
<< "0 <=" << true << LHS->getSourceRange() << RHS->getSourceRange();
} else
Match = false;
unsigned Diag = (isNonBooleanUnsignedValue(Other) && Value == 0)
? (HasEnumType(Other)
? diag::warn_unsigned_enum_always_true_comparison
: diag::warn_unsigned_always_true_comparison)
: diag::warn_tautological_constant_compare;
return Match;
// Should be enough for uint128 (39 decimal digits)
SmallString<64> PrettySourceValue;
llvm::raw_svector_ostream OS(PrettySourceValue);
OS << Value;
S.Diag(E->getOperatorLoc(), Diag)
<< RhsConstant << OType << E->getOpcodeStr() << OS.str() << Result
<< E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
return true;
}
void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
bool DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
Expr *Other, const llvm::APSInt &Value,
bool RhsConstant) {
// Disable warning in template instantiations.
if (S.inTemplateInstantiation())
return;
return false;
Constant = Constant->IgnoreParenImpCasts();
Other = Other->IgnoreParenImpCasts();
// TODO: Investigate using GetExprRange() to get tighter bounds
// on the bit ranges.
@ -8648,10 +8696,6 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
bool OtherIsBooleanType = Other->isKnownToHaveBooleanValue();
// 0 values are handled later by CheckTautologicalComparisonWithZero().
if ((Value == 0) && (!OtherIsBooleanType))
return;
BinaryOperatorKind op = E->getOpcode();
bool IsTrue = true;
@ -8667,7 +8711,7 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
QualType CommonT = E->getLHS()->getType();
if (S.Context.hasSameUnqualifiedType(OtherT, ConstantT))
return;
return false;
assert((OtherT->isIntegerType() && ConstantT->isIntegerType()) &&
"comparison with non-integer type");
@ -8682,38 +8726,38 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
// Check that the constant is representable in type OtherT.
if (ConstantSigned) {
if (OtherWidth >= Value.getMinSignedBits())
return;
return false;
} else { // !ConstantSigned
if (OtherWidth >= Value.getActiveBits() + 1)
return;
return false;
}
} else { // !OtherSigned
// Check that the constant is representable in type OtherT.
// Negative values are out of range.
if (ConstantSigned) {
if (Value.isNonNegative() && OtherWidth >= Value.getActiveBits())
return;
return false;
} else { // !ConstantSigned
if (OtherWidth >= Value.getActiveBits())
return;
return false;
}
}
} else { // !CommonSigned
if (OtherRange.NonNegative) {
if (OtherWidth >= Value.getActiveBits())
return;
return false;
} else { // OtherSigned
assert(!ConstantSigned &&
"Two signed types converted to unsigned types.");
// Check to see if the constant is representable in OtherT.
if (OtherWidth > Value.getActiveBits())
return;
return false;
// Check to see if the constant is equivalent to a negative value
// cast to CommonT.
if (S.Context.getIntWidth(ConstantT) ==
S.Context.getIntWidth(CommonT) &&
Value.isNegative() && Value.getMinSignedBits() <= OtherWidth)
return;
return false;
// The constant value rests between values that OtherT can represent
// after conversion. Relational comparison still works, but equality
// comparisons will be tautological.
@ -8726,7 +8770,7 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
if (op == BO_EQ || op == BO_NE) {
IsTrue = op == BO_NE;
} else if (EqualityOnly) {
return;
return false;
} else if (RhsConstant) {
if (op == BO_GT || op == BO_GE)
IsTrue = !PositiveConstant;
@ -8814,7 +8858,7 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
} else if (CmpRes == ATrue) {
IsTrue = true;
} else {
return;
return false;
}
}
@ -8837,6 +8881,8 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
<< OS.str() << LiteralOrBoolConstant
<< OtherT << (OtherIsBooleanType && !OtherT->isBooleanType()) << IsTrue
<< E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange());
return true;
}
/// Analyze the operands of the given comparison. Implements the
@ -8862,44 +8908,48 @@ void AnalyzeComparison(Sema &S, BinaryOperator *E) {
if (E->isValueDependent())
return AnalyzeImpConvsInComparison(S, E);
Expr *LHS = E->getLHS()->IgnoreParenImpCasts();
Expr *RHS = E->getRHS()->IgnoreParenImpCasts();
bool IsComparisonConstant = false;
// Check whether an integer constant comparison results in a value
// of 'true' or 'false'.
Expr *LHS = E->getLHS();
Expr *RHS = E->getRHS();
if (T->isIntegralType(S.Context)) {
llvm::APSInt RHSValue;
bool IsRHSIntegralLiteral =
RHS->isIntegerConstantExpr(RHSValue, S.Context);
llvm::APSInt LHSValue;
bool IsLHSIntegralLiteral =
LHS->isIntegerConstantExpr(LHSValue, S.Context);
if (IsRHSIntegralLiteral && !IsLHSIntegralLiteral)
DiagnoseOutOfRangeComparison(S, E, RHS, LHS, RHSValue, true);
else if (!IsRHSIntegralLiteral && IsLHSIntegralLiteral)
DiagnoseOutOfRangeComparison(S, E, LHS, RHS, LHSValue, false);
else
IsComparisonConstant =
(IsRHSIntegralLiteral && IsLHSIntegralLiteral);
} else if (!T->hasUnsignedIntegerRepresentation())
IsComparisonConstant = E->isIntegerConstantExpr(S.Context);
// We don't care about value-dependent expressions or expressions
// whose result is a constant.
if (IsComparisonConstant)
return AnalyzeImpConvsInComparison(S, E);
bool IsRHSIntegralLiteral = RHS->isIntegerConstantExpr(RHSValue, S.Context);
bool IsLHSIntegralLiteral = LHS->isIntegerConstantExpr(LHSValue, S.Context);
// If this is a tautological comparison, suppress -Wsign-compare.
if (CheckTautologicalComparisonWithZero(S, E))
return AnalyzeImpConvsInComparison(S, E);
// We don't care about expressions whose result is a constant.
if (IsRHSIntegralLiteral && IsLHSIntegralLiteral)
return AnalyzeImpConvsInComparison(S, E);
// We don't do anything special if this isn't an unsigned integral
// comparison: we're only interested in integral comparisons, and
// signed comparisons only happen in cases we don't care to warn about.
if (!T->hasUnsignedIntegerRepresentation())
// We only care about expressions where just one side is literal
if (IsRHSIntegralLiteral ^ IsLHSIntegralLiteral) {
// Is the constant on the RHS or LHS?
const bool RhsConstant = IsRHSIntegralLiteral;
Expr *Const = RhsConstant ? RHS : LHS;
Expr *Other = RhsConstant ? LHS : RHS;
const llvm::APSInt &Value = RhsConstant ? RHSValue : LHSValue;
// Check whether an integer constant comparison results in a value
// of 'true' or 'false'.
if (CheckTautologicalComparison(S, E, Const, Other, Value, RhsConstant))
return AnalyzeImpConvsInComparison(S, E);
if (DiagnoseOutOfRangeComparison(S, E, Const, Other, Value, RhsConstant))
return AnalyzeImpConvsInComparison(S, E);
}
}
if (!T->hasUnsignedIntegerRepresentation()) {
// We don't do anything special if this isn't an unsigned integral
// comparison: we're only interested in integral comparisons, and
// signed comparisons only happen in cases we don't care to warn about.
return AnalyzeImpConvsInComparison(S, E);
}
LHS = LHS->IgnoreParenImpCasts();
RHS = RHS->IgnoreParenImpCasts();
// Check to see if one of the (unmodified) operands is of different
// signedness.

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@ -7,58 +7,6 @@ int main()
{
int a = value();
if (a == 0x0000000000000000L)
return 0;
if (a != 0x0000000000000000L)
return 0;
if (a < 0x0000000000000000L)
return 0;
if (a <= 0x0000000000000000L)
return 0;
if (a > 0x0000000000000000L)
return 0;
if (a >= 0x0000000000000000L)
return 0;
if (0x0000000000000000L == a)
return 0;
if (0x0000000000000000L != a)
return 0;
if (0x0000000000000000L < a)
return 0;
if (0x0000000000000000L <= a)
return 0;
if (0x0000000000000000L > a)
return 0;
if (0x0000000000000000L >= a)
return 0;
if (a == 0x0000000000000000UL)
return 0;
if (a != 0x0000000000000000UL)
return 0;
if (a < 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return 0;
if (a <= 0x0000000000000000UL)
return 0;
if (a > 0x0000000000000000UL)
return 0;
if (a >= 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
return 0;
if (0x0000000000000000UL == a)
return 0;
if (0x0000000000000000UL != a)
return 0;
if (0x0000000000000000UL < a)
return 0;
if (0x0000000000000000UL <= a) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
return 0;
if (0x0000000000000000UL > a) // expected-warning {{comparison of 0 > unsigned expression is always false}}
return 0;
if (0x0000000000000000UL >= a)
return 0;
if (a == 0x1234567812345678L) // expected-warning {{comparison of constant 1311768465173141112 with expression of type 'int' is always false}}
return 0;
if (a != 0x1234567812345678L) // expected-warning {{comparison of constant 1311768465173141112 with expression of type 'int' is always true}}
@ -155,113 +103,6 @@ int main()
if (0x1234567812345678L >= l)
return 0;
unsigned un = 0;
if (un == 0x0000000000000000L)
return 0;
if (un != 0x0000000000000000L)
return 0;
if (un < 0x0000000000000000L) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return 0;
if (un <= 0x0000000000000000L)
return 0;
if (un > 0x0000000000000000L)
return 0;
if (un >= 0x0000000000000000L) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
return 0;
if (0x0000000000000000L == un)
return 0;
if (0x0000000000000000L != un)
return 0;
if (0x0000000000000000L < un)
return 0;
if (0x0000000000000000L <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
return 0;
if (0x0000000000000000L > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
return 0;
if (0x0000000000000000L >= un)
return 0;
if (un == 0x0000000000000000UL)
return 0;
if (un != 0x0000000000000000UL)
return 0;
if (un < 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return 0;
if (un <= 0x0000000000000000UL)
return 0;
if (un > 0x0000000000000000UL)
return 0;
if (un >= 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
return 0;
if (0x0000000000000000UL == un)
return 0;
if (0x0000000000000000UL != un)
return 0;
if (0x0000000000000000UL < un)
return 0;
if (0x0000000000000000UL <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
return 0;
if (0x0000000000000000UL > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
return 0;
if (0x0000000000000000UL >= un)
return 0;
float fl = 0;
if (fl == 0x0000000000000000L)
return 0;
if (fl != 0x0000000000000000L)
return 0;
if (fl < 0x0000000000000000L)
return 0;
if (fl <= 0x0000000000000000L)
return 0;
if (fl > 0x0000000000000000L)
return 0;
if (fl >= 0x0000000000000000L)
return 0;
if (0x0000000000000000L == fl)
return 0;
if (0x0000000000000000L != fl)
return 0;
if (0x0000000000000000L < fl)
return 0;
if (0x0000000000000000L <= fl)
return 0;
if (0x0000000000000000L > fl)
return 0;
if (0x0000000000000000L >= fl)
return 0;
double dl = 0;
if (dl == 0x0000000000000000L)
return 0;
if (dl != 0x0000000000000000L)
return 0;
if (dl < 0x0000000000000000L)
return 0;
if (dl <= 0x0000000000000000L)
return 0;
if (dl > 0x0000000000000000L)
return 0;
if (dl >= 0x0000000000000000L)
return 0;
if (0x0000000000000000L == dl)
return 0;
if (0x0000000000000000L != dl)
return 0;
if (0x0000000000000000L < dl)
return 0;
if (0x0000000000000000L <= dl)
return 0;
if (0x0000000000000000L > dl)
return 0;
if (0x0000000000000000L >= dl)
return 0;
enum E {
yes,
no,

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@ -0,0 +1,514 @@
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -DTEST -verify %s
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wno-tautological-constant-compare -verify %s
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -DTEST -verify -x c++ %s
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wno-tautological-constant-compare -verify -x c++ %s
int value(void);
#define macro(val) val
#ifdef __cplusplus
template<typename T>
void TFunc() {
// Make sure that we do warn for normal variables in template functions !
unsigned char c = value();
#ifdef TEST
if (c > 255) // expected-warning {{comparison 'unsigned char' > 255 is always false}}
return;
#else
if (c > 255)
return;
#endif
if (c > macro(255))
return;
T v = value();
if (v > 255)
return;
if (v > 32767)
return;
}
#endif
int main()
{
#ifdef __cplusplus
TFunc<unsigned char>();
TFunc<signed short>();
#endif
short s = value();
#ifdef TEST
if (s == 32767)
return 0;
if (s != 32767)
return 0;
if (s < 32767)
return 0;
if (s <= 32767) // expected-warning {{comparison 'short' <= 32767 is always true}}
return 0;
if (s > 32767) // expected-warning {{comparison 'short' > 32767 is always false}}
return 0;
if (s >= 32767)
return 0;
if (32767 == s)
return 0;
if (32767 != s)
return 0;
if (32767 < s) // expected-warning {{comparison 32767 < 'short' is always false}}
return 0;
if (32767 <= s)
return 0;
if (32767 > s)
return 0;
if (32767 >= s) // expected-warning {{comparison 32767 >= 'short' is always true}}
return 0;
// FIXME: assumes two's complement
if (s == -32768)
return 0;
if (s != -32768)
return 0;
if (s < -32768) // expected-warning {{comparison 'short' < -32768 is always false}}
return 0;
if (s <= -32768)
return 0;
if (s > -32768)
return 0;
if (s >= -32768) // expected-warning {{comparison 'short' >= -32768 is always true}}
return 0;
if (-32768 == s)
return 0;
if (-32768 != s)
return 0;
if (-32768 < s)
return 0;
if (-32768 <= s) // expected-warning {{comparison -32768 <= 'short' is always true}}
return 0;
if (-32768 > s) // expected-warning {{comparison -32768 > 'short' is always false}}
return 0;
if (-32768 >= s)
return 0;
if (s == 32767UL)
return 0;
if (s != 32767UL)
return 0;
if (s < 32767UL)
return 0;
if (s <= 32767UL) // expected-warning {{comparison 'short' <= 32767 is always true}}
return 0;
if (s > 32767UL) // expected-warning {{comparison 'short' > 32767 is always false}}
return 0;
if (s >= 32767UL)
return 0;
if (32767UL == s)
return 0;
if (32767UL != s)
return 0;
if (32767UL < s) // expected-warning {{comparison 32767 < 'short' is always false}}
return 0;
if (32767UL <= s)
return 0;
if (32767UL > s)
return 0;
if (32767UL >= s) // expected-warning {{comparison 32767 >= 'short' is always true}}
return 0;
// FIXME: assumes two's complement
if (s == -32768L)
return 0;
if (s != -32768L)
return 0;
if (s < -32768L) // expected-warning {{comparison 'short' < -32768 is always false}}
return 0;
if (s <= -32768L)
return 0;
if (s > -32768L)
return 0;
if (s >= -32768L) // expected-warning {{comparison 'short' >= -32768 is always true}}
return 0;
if (-32768L == s)
return 0;
if (-32768L != s)
return 0;
if (-32768L < s)
return 0;
if (-32768L <= s) // expected-warning {{comparison -32768 <= 'short' is always true}}
return 0;
if (-32768L > s) // expected-warning {{comparison -32768 > 'short' is always false}}
return 0;
if (-32768L >= s)
return 0;
#else
// expected-no-diagnostics
if (s == 32767)
return 0;
if (s != 32767)
return 0;
if (s < 32767)
return 0;
if (s <= 32767)
return 0;
if (s > 32767)
return 0;
if (s >= 32767)
return 0;
if (32767 == s)
return 0;
if (32767 != s)
return 0;
if (32767 < s)
return 0;
if (32767 <= s)
return 0;
if (32767 > s)
return 0;
if (32767 >= s)
return 0;
// FIXME: assumes two's complement
if (s == -32768)
return 0;
if (s != -32768)
return 0;
if (s < -32768)
return 0;
if (s <= -32768)
return 0;
if (s > -32768)
return 0;
if (s >= -32768)
return 0;
if (-32768 == s)
return 0;
if (-32768 != s)
return 0;
if (-32768 < s)
return 0;
if (-32768 <= s)
return 0;
if (-32768 > s)
return 0;
if (-32768 >= s)
return 0;
if (s == 32767UL)
return 0;
if (s != 32767UL)
return 0;
if (s < 32767UL)
return 0;
if (s <= 32767UL)
return 0;
if (s > 32767UL)
return 0;
if (s >= 32767UL)
return 0;
if (32767UL == s)
return 0;
if (32767UL != s)
return 0;
if (32767UL < s)
return 0;
if (32767UL <= s)
return 0;
if (32767UL > s)
return 0;
if (32767UL >= s)
return 0;
// FIXME: assumes two's complement
if (s == -32768L)
return 0;
if (s != -32768L)
return 0;
if (s < -32768L)
return 0;
if (s <= -32768L)
return 0;
if (s > -32768L)
return 0;
if (s >= -32768L)
return 0;
if (-32768L == s)
return 0;
if (-32768L != s)
return 0;
if (-32768L < s)
return 0;
if (-32768L <= s)
return 0;
if (-32768L > s)
return 0;
if (-32768L >= s)
return 0;
#endif
if (s == 0)
return 0;
if (s != 0)
return 0;
if (s < 0)
return 0;
if (s <= 0)
return 0;
if (s > 0)
return 0;
if (s >= 0)
return 0;
if (0 == s)
return 0;
if (0 != s)
return 0;
if (0 < s)
return 0;
if (0 <= s)
return 0;
if (0 > s)
return 0;
if (0 >= s)
return 0;
// However the comparison with 0U would warn
unsigned short us = value();
#ifdef TEST
if (us == 65535)
return 0;
if (us != 65535)
return 0;
if (us < 65535)
return 0;
if (us <= 65535) // expected-warning {{comparison 'unsigned short' <= 65535 is always true}}
return 0;
if (us > 65535) // expected-warning {{comparison 'unsigned short' > 65535 is always false}}
return 0;
if (us >= 65535)
return 0;
if (65535 == us)
return 0;
if (65535 != us)
return 0;
if (65535 < us) // expected-warning {{comparison 65535 < 'unsigned short' is always false}}
return 0;
if (65535 <= us)
return 0;
if (65535 > us)
return 0;
if (65535 >= us) // expected-warning {{comparison 65535 >= 'unsigned short' is always true}}
return 0;
if (us == 65535UL)
return 0;
if (us != 65535UL)
return 0;
if (us < 65535UL)
return 0;
if (us <= 65535UL) // expected-warning {{comparison 'unsigned short' <= 65535 is always true}}
return 0;
if (us > 65535UL) // expected-warning {{comparison 'unsigned short' > 65535 is always false}}
return 0;
if (us >= 65535UL)
return 0;
if (65535UL == us)
return 0;
if (65535UL != us)
return 0;
if (65535UL < us) // expected-warning {{comparison 65535 < 'unsigned short' is always false}}
return 0;
if (65535UL <= us)
return 0;
if (65535UL > us)
return 0;
if (65535UL >= us) // expected-warning {{comparison 65535 >= 'unsigned short' is always true}}
return 0;
#else
// expected-no-diagnostics
if (us == 65535)
return 0;
if (us != 65535)
return 0;
if (us < 65535)
return 0;
if (us <= 65535)
return 0;
if (us > 65535)
return 0;
if (us >= 65535)
return 0;
if (65535 == us)
return 0;
if (65535 != us)
return 0;
if (65535 < us)
return 0;
if (65535 <= us)
return 0;
if (65535 > us)
return 0;
if (65535 >= us)
return 0;
if (us == 65535UL)
return 0;
if (us != 65535UL)
return 0;
if (us < 65535UL)
return 0;
if (us <= 65535UL)
return 0;
if (us > 65535UL)
return 0;
if (us >= 65535UL)
return 0;
if (65535UL == us)
return 0;
if (65535UL != us)
return 0;
if (65535UL < us)
return 0;
if (65535UL <= us)
return 0;
if (65535UL > us)
return 0;
if (65535UL >= us)
return 0;
#endif
if (us == 32767)
return 0;
if (us != 32767)
return 0;
if (us < 32767)
return 0;
if (us <= 32767)
return 0;
if (us > 32767)
return 0;
if (us >= 32767)
return 0;
if (32767 == us)
return 0;
if (32767 != us)
return 0;
if (32767 < us)
return 0;
if (32767 <= us)
return 0;
if (32767 > us)
return 0;
if (32767 >= us)
return 0;
if (us == 32767UL)
return 0;
if (us != 32767UL)
return 0;
if (us < 32767UL)
return 0;
if (us <= 32767UL)
return 0;
if (us > 32767UL)
return 0;
if (us >= 32767UL)
return 0;
if (32767UL == us)
return 0;
if (32767UL != us)
return 0;
if (32767UL < us)
return 0;
if (32767UL <= us)
return 0;
if (32767UL > us)
return 0;
if (32767UL >= us)
return 0;
#if __SIZEOF_INT128__
__int128 i128;
if (i128 == -1) // used to crash
return 0;
#endif
enum E {
yes,
no,
maybe
};
enum E e;
if (e == yes)
return 0;
if (e != yes)
return 0;
if (e < yes)
return 0;
if (e <= yes)
return 0;
if (e > yes)
return 0;
if (e >= yes)
return 0;
if (yes == e)
return 0;
if (yes != e)
return 0;
if (yes < e)
return 0;
if (yes <= e)
return 0;
if (yes > e)
return 0;
if (yes >= e)
return 0;
if (e == maybe)
return 0;
if (e != maybe)
return 0;
if (e < maybe)
return 0;
if (e <= maybe)
return 0;
if (e > maybe)
return 0;
if (e >= maybe)
return 0;
if (maybe == e)
return 0;
if (maybe != e)
return 0;
if (maybe < e)
return 0;
if (maybe <= e)
return 0;
if (maybe > e)
return 0;
if (maybe >= e)
return 0;
return 1;
}

View File

@ -1,47 +1,370 @@
// RUN: %clang_cc1 -fsyntax-only -DTEST -verify %s
// RUN: %clang_cc1 -fsyntax-only -Wno-tautological-unsigned-zero-compare -verify %s
// RUN: %clang_cc1 -fsyntax-only -DTEST -verify -x c++ %s
// RUN: %clang_cc1 -fsyntax-only -Wno-tautological-unsigned-zero-compare -verify -x c++ %s
unsigned value(void);
unsigned uvalue(void);
signed int svalue(void);
int main() {
unsigned un = value();
#define macro(val) val
#ifdef __cplusplus
template<typename T>
void TFunc() {
// Make sure that we do warn for normal variables in template functions !
unsigned char c = svalue();
#ifdef TEST
if (c < 0) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return;
#else
if (c < 0)
return;
#endif
if (c < macro(0))
return;
T v = svalue();
if (v < 0)
return;
}
#endif
int main()
{
#ifdef __cplusplus
TFunc<unsigned char>();
TFunc<unsigned short>();
#endif
unsigned un = uvalue();
#ifdef TEST
if (un == 0)
return 0;
if (un != 0)
return 0;
if (un < 0) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return 0;
return 0;
if (un <= 0)
return 0;
if (un > 0)
return 0;
if (un >= 0) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
return 0;
return 0;
if (0 == un)
return 0;
if (0 != un)
return 0;
if (0 < un)
return 0;
if (0 <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
return 0;
return 0;
if (0 > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
return 0;
if (un < 0U) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return 0;
if (un >= 0U) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
return 0;
if (0U <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
return 0;
if (0U > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
return 0;
return 0;
if (0 >= un)
return 0;
if (un == 0UL)
return 0;
if (un != 0UL)
return 0;
if (un < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return 0;
if (un <= 0UL)
return 0;
if (un > 0UL)
return 0;
if (un >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
return 0;
if (0UL == un)
return 0;
if (0UL != un)
return 0;
if (0UL < un)
return 0;
if (0UL <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
return 0;
if (0UL > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
return 0;
if (0UL >= un)
return 0;
#else
// expected-no-diagnostics
if (un == 0)
return 0;
if (un != 0)
return 0;
if (un < 0)
return 0;
return 0;
if (un <= 0)
return 0;
if (un > 0)
return 0;
if (un >= 0)
return 0;
return 0;
if (0 == un)
return 0;
if (0 != un)
return 0;
if (0 < un)
return 0;
if (0 <= un)
return 0;
return 0;
if (0 > un)
return 0;
if (un < 0U)
return 0;
if (un >= 0U)
return 0;
if (0U <= un)
return 0;
if (0U > un)
return 0;
return 0;
if (0 >= un)
return 0;
if (un == 0UL)
return 0;
if (un != 0UL)
return 0;
if (un < 0UL)
return 0;
if (un <= 0UL)
return 0;
if (un > 0UL)
return 0;
if (un >= 0UL)
return 0;
if (0UL == un)
return 0;
if (0UL != un)
return 0;
if (0UL < un)
return 0;
if (0UL <= un)
return 0;
if (0UL > un)
return 0;
if (0UL >= un)
return 0;
#endif
signed int a = svalue();
#ifdef TEST
if (a == 0)
return 0;
if (a != 0)
return 0;
if (a < 0)
return 0;
if (a <= 0)
return 0;
if (a > 0)
return 0;
if (a >= 0)
return 0;
if (0 == a)
return 0;
if (0 != a)
return 0;
if (0 < a)
return 0;
if (0 <= a)
return 0;
if (0 > a)
return 0;
if (0 >= a)
return 0;
if (a == 0UL)
return 0;
if (a != 0UL)
return 0;
if (a < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
return 0;
if (a <= 0UL)
return 0;
if (a > 0UL)
return 0;
if (a >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
return 0;
if (0UL == a)
return 0;
if (0UL != a)
return 0;
if (0UL < a)
return 0;
if (0UL <= a) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
return 0;
if (0UL > a) // expected-warning {{comparison of 0 > unsigned expression is always false}}
return 0;
if (0UL >= a)
return 0;
#else
// expected-no-diagnostics
if (a == 0)
return 0;
if (a != 0)
return 0;
if (a < 0)
return 0;
if (a <= 0)
return 0;
if (a > 0)
return 0;
if (a >= 0)
return 0;
if (0 == a)
return 0;
if (0 != a)
return 0;
if (0 < a)
return 0;
if (0 <= a)
return 0;
if (0 > a)
return 0;
if (0 >= a)
return 0;
if (a == 0UL)
return 0;
if (a != 0UL)
return 0;
if (a < 0UL)
return 0;
if (a <= 0UL)
return 0;
if (a > 0UL)
return 0;
if (a >= 0UL)
return 0;
if (0UL == a)
return 0;
if (0UL != a)
return 0;
if (0UL < a)
return 0;
if (0UL <= a)
return 0;
if (0UL > a)
return 0;
if (0UL >= a)
return 0;
#endif
float fl = 0;
if (fl == 0)
return 0;
if (fl != 0)
return 0;
if (fl < 0)
return 0;
if (fl <= 0)
return 0;
if (fl > 0)
return 0;
if (fl >= 0)
return 0;
if (0 == fl)
return 0;
if (0 != fl)
return 0;
if (0 < fl)
return 0;
if (0 <= fl)
return 0;
if (0 > fl)
return 0;
if (0 >= fl)
return 0;
if (fl == 0UL)
return 0;
if (fl != 0UL)
return 0;
if (fl < 0UL)
return 0;
if (fl <= 0UL)
return 0;
if (fl > 0UL)
return 0;
if (fl >= 0UL)
return 0;
if (0UL == fl)
return 0;
if (0UL != fl)
return 0;
if (0UL < fl)
return 0;
if (0UL <= fl)
return 0;
if (0UL > fl)
return 0;
if (0UL >= fl)
return 0;
double dl = 0;
if (dl == 0)
return 0;
if (dl != 0)
return 0;
if (dl < 0)
return 0;
if (dl <= 0)
return 0;
if (dl > 0)
return 0;
if (dl >= 0)
return 0;
if (0 == dl)
return 0;
if (0 != dl)
return 0;
if (0 < dl)
return 0;
if (0 <= dl)
return 0;
if (0 > dl)
return 0;
if (0 >= dl)
return 0;
if (dl == 0UL)
return 0;
if (dl != 0UL)
return 0;
if (dl < 0UL)
return 0;
if (dl <= 0UL)
return 0;
if (dl > 0UL)
return 0;
if (dl >= 0UL)
return 0;
if (0UL == dl)
return 0;
if (0UL != dl)
return 0;
if (0UL < dl)
return 0;
if (0UL <= dl)
return 0;
if (0UL > dl)
return 0;
if (0UL >= dl)
return 0;
return 1;
}