Commit 4f42fc4e authored by Justin Bogner's avatar Justin Bogner
Browse files

Sema: Handle C11 atomics when diagnosing out of range comparisons 

This fixes a couple of asserts when analyzing comparisons involving
C11 atomics that were uncovered by r205608 when we extended the
applicability of -Wtautological-constant-out-of-range-compare.

llvm-svn: 213573
parent 913666f9

clang/lib/Sema/SemaChecking.cpp

+6 −0
Original line number Diff line number Diff line
@@ -4943,6 +4943,8 @@ struct IntRange { 
      T = VT->getElementType().getTypePtr();

    if (const ComplexType *CT = dyn_cast<ComplexType>(T))

      T = CT->getElementType().getTypePtr();

    if (const AtomicType *AT = dyn_cast<AtomicType>(T))

      T = AT->getValueType().getTypePtr();



    // For enum types, use the known bit width of the enumerators.

    if (const EnumType *ET = dyn_cast<EnumType>(T)) {
@@ -4978,6 +4980,8 @@ struct IntRange { 
      T = VT->getElementType().getTypePtr();

    if (const ComplexType *CT = dyn_cast<ComplexType>(T))

      T = CT->getElementType().getTypePtr();

    if (const AtomicType *AT = dyn_cast<AtomicType>(T))

      T = AT->getValueType().getTypePtr();

    if (const EnumType *ET = dyn_cast<EnumType>(T))

      T = C.getCanonicalType(ET->getDecl()->getIntegerType()).getTypePtr();
@@ -5380,6 +5384,8 @@ static void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, 
  // TODO: Investigate using GetExprRange() to get tighter bounds

  // on the bit ranges.

  QualType OtherT = Other->getType();

  if (const AtomicType *AT = dyn_cast<AtomicType>(OtherT))

    OtherT = AT->getValueType();

  IntRange OtherRange = IntRange::forValueOfType(S.Context, OtherT);

  unsigned OtherWidth = OtherRange.Width;

clang/test/Sema/atomic-compare.c

0 → 100644
+21 −0
Original line number Diff line number Diff line 
// RUN: %clang_cc1 %s -verify -fsyntax-only



void f(_Atomic(int) a, _Atomic(int) b) {

  if (a > b)      {} // no warning

  if (a < b)      {} // no warning

  if (a >= b)     {} // no warning

  if (a <= b)     {} // no warning

  if (a == b)     {} // no warning

  if (a != b)     {} // no warning



  if (a == 0) {} // no warning

  if (a > 0) {} // no warning

  if (a > 1) {} // no warning

  if (a > 2) {} // no warning



  if (!a > 0) {}  // no warning

  if (!a > 1)     {} // expected-warning {{comparison of constant 1 with boolean expression is always false}}

  if (!a > 2)     {} // expected-warning {{comparison of constant 2 with boolean expression is always false}}

  if (!a > b)     {} // no warning

  if (!a > -1)    {} // expected-warning {{comparison of constant -1 with boolean expression is always true}}

}

clang/test/Sema/atomic-expr.c

+3 −0
Original line number Diff line number Diff line
@@ -58,3 +58,6 @@ int func_13 (int x, unsigned y) { 
  return x ? data1 : y;

}



int func_14 () {

  return data1 == 0;

}