r315614 - [Sema] Diagnose tautological comparison with type's min/max values

Nico Weber via cfe-commits cfe-commits at lists.llvm.org
Thu Oct 12 14:12:35 PDT 2017


Huh, I consider clang not warning on this a feature, not a bug. Why are we
trying to match what gcc does here?

Say you have code like this:

    int64_t aligned_start = 0;
    int64_t aligned_size = 0;
    CalculateVMAlignedBoundaries(region.offset,
                                 region.size,
                                 &aligned_start,
                                 &aligned_size,
                                 &data_offset);

    // Ensure that the casts in the mmap call below are sane.
    if (aligned_start < 0 || aligned_size < 0 ||
        aligned_start > std::numeric_limits<off_t>::max() ||
        static_cast<uint64_t>(aligned_size) >
            std::numeric_limits<size_t>::max() ||
        static_cast<uint64_t>(region.size) >
            std::numeric_limits<size_t>::max()) {
      DLOG(ERROR) << "Region bounds are not valid for mmap";
      return false;
    }

This code works in 64-bit and 32-bit. off_t has different sizes on both, so
the comparison is useful. The warning uselessly fires on this code.

On Thu, Oct 12, 2017 at 4:16 PM, Roman Lebedev via cfe-commits <
cfe-commits at lists.llvm.org> wrote:

> Author: lebedevri
> Date: Thu Oct 12 13:16:51 2017
> New Revision: 315614
>
> URL: http://llvm.org/viewvc/llvm-project?rev=315614&view=rev
> Log:
> [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
>
> Added:
>     cfe/trunk/test/Sema/tautological-constant-compare.c
> Modified:
>     cfe/trunk/docs/ReleaseNotes.rst
>     cfe/trunk/include/clang/Basic/DiagnosticGroups.td
>     cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>     cfe/trunk/lib/Sema/SemaChecking.cpp
>     cfe/trunk/test/Sema/outof-range-constant-compare.c
>     cfe/trunk/test/Sema/tautological-unsigned-zero-compare.c
>
> Modified: cfe/trunk/docs/ReleaseNotes.rst
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/
> ReleaseNotes.rst?rev=315614&r1=315613&r2=315614&view=diff
> ============================================================
> ==================
> --- cfe/trunk/docs/ReleaseNotes.rst (original)
> +++ cfe/trunk/docs/ReleaseNotes.rst Thu Oct 12 13:16:51 2017
> @@ -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
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticGroups.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/
> clang/Basic/DiagnosticGroups.td?rev=315614&r1=315613&r2=315614&view=diff
> ============================================================
> ==================
> --- cfe/trunk/include/clang/Basic/DiagnosticGroups.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticGroups.td Thu Oct 12 13:16:51
> 2017
> @@ -432,13 +432,15 @@ def StrncatSize : DiagGroup<"strncat-siz
>  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]>;
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/
> DiagnosticSemaKinds.td?rev=315614&r1=315613&r2=315614&view=diff
> ============================================================
> ==================
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu Oct 12
> 13:16:51 2017
> @@ -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">,
>
> Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/
> SemaChecking.cpp?rev=315614&r1=315613&r2=315614&view=diff
> ============================================================
> ==================
> --- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaChecking.cpp Thu Oct 12 13:16:51 2017
> @@ -8553,19 +8553,71 @@ bool IsSameFloatAfterCast(const APValue
>
>  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;
> +
> +  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;
>
> -  llvm::APSInt Value;
> -  return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
> +  // 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.
> +
> +  const bool Result = ResultWhenConstEqualsOther;
> +
> +  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;
>
> -  bool Match = true;
> +  // Should be enough for uint128 (39 decimal digits)
> +  SmallString<64> PrettySourceValue;
> +  llvm::raw_svector_ostream OS(PrettySourceValue);
> +  OS << Value;
>
> -  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;
> +  S.Diag(E->getOperatorLoc(), Diag)
> +      << RhsConstant << OType << E->getOpcodeStr() << OS.str() << Result
> +      << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
>
> -  return Match;
> +  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 &
>
>    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 &
>      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 &
>          // 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 &
>      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 &
>      } else if (CmpRes == ATrue) {
>        IsTrue = true;
>      } else {
> -      return;
> +      return false;
>      }
>    }
>
> @@ -8837,6 +8881,8 @@ void DiagnoseOutOfRangeComparison(Sema &
>          << 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, BinaryOp
>    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);
>
> -  // If this is a tautological comparison, suppress -Wsign-compare.
> -  if (CheckTautologicalComparisonWithZero(S, E))
> -    return AnalyzeImpConvsInComparison(S, E);
> +    bool IsRHSIntegralLiteral = RHS->isIntegerConstantExpr(RHSValue,
> S.Context);
> +    bool IsLHSIntegralLiteral = LHS->isIntegerConstantExpr(LHSValue,
> S.Context);
> +
> +    // We don't care about expressions whose result is a constant.
> +    if (IsRHSIntegralLiteral && IsLHSIntegralLiteral)
> +      return AnalyzeImpConvsInComparison(S, E);
> +
> +    // 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;
>
> -  // 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())
> +      // 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.
>
> Modified: cfe/trunk/test/Sema/outof-range-constant-compare.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/
> outof-range-constant-compare.c?rev=315614&r1=315613&r2=315614&view=diff
> ============================================================
> ==================
> --- cfe/trunk/test/Sema/outof-range-constant-compare.c (original)
> +++ cfe/trunk/test/Sema/outof-range-constant-compare.c Thu Oct 12
> 13:16:51 2017
> @@ -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,
>
> Added: cfe/trunk/test/Sema/tautological-constant-compare.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/
> tautological-constant-compare.c?rev=315614&view=auto
> ============================================================
> ==================
> --- cfe/trunk/test/Sema/tautological-constant-compare.c (added)
> +++ cfe/trunk/test/Sema/tautological-constant-compare.c Thu Oct 12
> 13:16:51 2017
> @@ -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;
> +}
>
> Modified: cfe/trunk/test/Sema/tautological-unsigned-zero-compare.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/
> tautological-unsigned-zero-compare.c?rev=315614&r1=
> 315613&r2=315614&view=diff
> ============================================================
> ==================
> --- cfe/trunk/test/Sema/tautological-unsigned-zero-compare.c (original)
> +++ cfe/trunk/test/Sema/tautological-unsigned-zero-compare.c Thu Oct 12
> 13:16:51 2017
> @@ -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;
>  }
>
>
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>
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