[cfe-commits] r59583 - in /cfe/trunk: lib/Sema/SemaExpr.cpp lib/Sema/SemaOverload.cpp test/SemaCXX/overloaded-builtin-operators.cpp test/SemaCXX/overloaded-operator.cpp

Douglas Gregor doug.gregor at gmail.com
Tue Nov 18 19:25:37 PST 2008


Author: dgregor
Date: Tue Nov 18 21:25:36 2008
New Revision: 59583

URL: http://llvm.org/viewvc/llvm-project?rev=59583&view=rev
Log:
Built-in equality and relational operators have return type "bool" in C++,
not "int".

Fix a typo in the promotion of enumeration types that was causing some
integral promotions to look like integral conversions (leading to
extra ambiguities in overload resolution).

Check for "acceptable" overloaded operators based on the types of the
arguments. This is a somewhat odd check that is specified by the
standard, but I can't see why it actually matters: the overload
candidates it suppresses don't seem like they would ever be picked as
the best candidates.


Modified:
    cfe/trunk/lib/Sema/SemaExpr.cpp
    cfe/trunk/lib/Sema/SemaOverload.cpp
    cfe/trunk/test/SemaCXX/overloaded-builtin-operators.cpp
    cfe/trunk/test/SemaCXX/overloaded-operator.cpp

Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=59583&r1=59582&r2=59583&view=diff

==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Tue Nov 18 21:25:36 2008
@@ -2145,9 +2145,12 @@
           Diag(Loc, diag::warn_selfcomparison);      
   }
   
+  // The result of comparisons is 'bool' in C++, 'int' in C.
+  QualType ResultTy = getLangOptions().CPlusPlus? Context.BoolTy : Context.IntTy;
+
   if (isRelational) {
     if (lType->isRealType() && rType->isRealType())
-      return Context.IntTy;
+      return ResultTy;
   } else {
     // Check for comparisons of floating point operands using != and ==.
     if (lType->isFloatingType()) {
@@ -2156,7 +2159,7 @@
     }
     
     if (lType->isArithmeticType() && rType->isArithmeticType())
-      return Context.IntTy;
+      return ResultTy;
   }
   
   bool LHSIsNull = lex->isNullPointerConstant(Context);
@@ -2181,7 +2184,7 @@
         << lex->getSourceRange() << rex->getSourceRange();
     }
     ImpCastExprToType(rex, lType); // promote the pointer to pointer
-    return Context.IntTy;
+    return ResultTy;
   }
   // Handle block pointer types.
   if (lType->isBlockPointerType() && rType->isBlockPointerType()) {
@@ -2195,7 +2198,7 @@
         << lex->getSourceRange() << rex->getSourceRange();
     }
     ImpCastExprToType(rex, lType); // promote the pointer to pointer
-    return Context.IntTy;
+    return ResultTy;
   }
   // Allow block pointers to be compared with null pointer constants.
   if ((lType->isBlockPointerType() && rType->isPointerType()) ||
@@ -2206,7 +2209,7 @@
         << lex->getSourceRange() << rex->getSourceRange();
     }
     ImpCastExprToType(rex, lType); // promote the pointer to pointer
-    return Context.IntTy;
+    return ResultTy;
   }
 
   if ((lType->isObjCQualifiedIdType() || rType->isObjCQualifiedIdType())) {
@@ -2224,21 +2227,21 @@
           << lType.getAsString() << rType.getAsString()
           << lex->getSourceRange() << rex->getSourceRange();
         ImpCastExprToType(rex, lType);
-        return Context.IntTy;
+        return ResultTy;
       }
       ImpCastExprToType(rex, lType);
-      return Context.IntTy;
+      return ResultTy;
     }
     if (ObjCQualifiedIdTypesAreCompatible(lType, rType, true)) {
       ImpCastExprToType(rex, lType);
-      return Context.IntTy;
+      return ResultTy;
     } else {
       if ((lType->isObjCQualifiedIdType() && rType->isObjCQualifiedIdType())) {
         Diag(Loc, diag::warn_incompatible_qualified_id_operands)
           << lType.getAsString() << rType.getAsString()
           << lex->getSourceRange() << rex->getSourceRange();
         ImpCastExprToType(rex, lType);
-        return Context.IntTy;
+        return ResultTy;
       }
     }
   }
@@ -2249,7 +2252,7 @@
         << lType.getAsString() << rType.getAsString()
         << lex->getSourceRange() << rex->getSourceRange();
     ImpCastExprToType(rex, lType); // promote the integer to pointer
-    return Context.IntTy;
+    return ResultTy;
   }
   if (lType->isIntegerType() && 
       (rType->isPointerType() || rType->isObjCQualifiedIdType())) {
@@ -2258,7 +2261,7 @@
         << lType.getAsString() << rType.getAsString()
         << lex->getSourceRange() << rex->getSourceRange();
     ImpCastExprToType(lex, rType); // promote the integer to pointer
-    return Context.IntTy;
+    return ResultTy;
   }
   // Handle block pointers.
   if (lType->isBlockPointerType() && rType->isIntegerType()) {
@@ -2267,7 +2270,7 @@
         << lType.getAsString() << rType.getAsString()
         << lex->getSourceRange() << rex->getSourceRange();
     ImpCastExprToType(rex, lType); // promote the integer to pointer
-    return Context.IntTy;
+    return ResultTy;
   }
   if (lType->isIntegerType() && rType->isBlockPointerType()) {
     if (!LHSIsNull)
@@ -2275,7 +2278,7 @@
         << lType.getAsString() << rType.getAsString()
         << lex->getSourceRange() << rex->getSourceRange();
     ImpCastExprToType(lex, rType); // promote the integer to pointer
-    return Context.IntTy;
+    return ResultTy;
   }
   return InvalidOperands(Loc, lex, rex);
 }

Modified: cfe/trunk/lib/Sema/SemaOverload.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOverload.cpp?rev=59583&r1=59582&r2=59583&view=diff

==============================================================================
--- cfe/trunk/lib/Sema/SemaOverload.cpp (original)
+++ cfe/trunk/lib/Sema/SemaOverload.cpp Tue Nov 18 21:25:36 2008
@@ -637,7 +637,7 @@
       Context.IntTy, Context.UnsignedIntTy, 
       Context.LongTy, Context.UnsignedLongTy 
     };
-    for (int Idx = 0; Idx < 0; ++Idx) {
+    for (int Idx = 0; Idx < 4; ++Idx) {
       uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
       if (FromSize < ToSize ||
           (FromSize == ToSize && 
@@ -1712,6 +1712,42 @@
   }
 }
 
+/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
+/// an acceptable non-member overloaded operator for a call whose
+/// arguments have types T1 (and, if non-empty, T2). This routine
+/// implements the check in C++ [over.match.oper]p3b2 concerning
+/// enumeration types.
+static bool 
+IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn,
+                                       QualType T1, QualType T2,
+                                       ASTContext &Context) {
+  if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
+    return true;
+
+  const FunctionTypeProto *Proto = Fn->getType()->getAsFunctionTypeProto();
+  if (Proto->getNumArgs() < 1)
+    return false;
+
+  if (T1->isEnumeralType()) {
+    QualType ArgType = Proto->getArgType(0).getNonReferenceType();
+    if (Context.getCanonicalType(T1).getUnqualifiedType()
+          == Context.getCanonicalType(ArgType).getUnqualifiedType())
+      return true;
+  }
+
+  if (Proto->getNumArgs() < 2)
+    return false;
+
+  if (!T2.isNull() && T2->isEnumeralType()) {
+    QualType ArgType = Proto->getArgType(1).getNonReferenceType();
+    if (Context.getCanonicalType(T2).getUnqualifiedType()
+          == Context.getCanonicalType(ArgType).getUnqualifiedType())
+      return true;
+  }
+
+  return false;
+}
+
 /// AddOperatorCandidates - Add the overloaded operator candidates for
 /// the operator Op that was used in an operator expression such as "x
 /// Op y". S is the scope in which the expression occurred (used for
@@ -1790,18 +1826,19 @@
       break;
     }
 
-    // FIXME: check that strange "However" condition above. It's going
-    // to need a special test.
-    if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(NonMemberOps))
-      AddOverloadCandidate(FD, Args, NumArgs, CandidateSet,
-                           /*SuppressUserConversions=*/false);
-    else if (OverloadedFunctionDecl *Ovl
-               = dyn_cast_or_null<OverloadedFunctionDecl>(NonMemberOps)) {
+    if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(NonMemberOps)) {
+      if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context))
+        AddOverloadCandidate(FD, Args, NumArgs, CandidateSet,
+                             /*SuppressUserConversions=*/false);
+    } else if (OverloadedFunctionDecl *Ovl
+                 = dyn_cast_or_null<OverloadedFunctionDecl>(NonMemberOps)) {
       for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(),
                                                   FEnd = Ovl->function_end();
-           F != FEnd; ++F)
-        AddOverloadCandidate(*F, Args, NumArgs, CandidateSet, 
-                             /*SuppressUserConversions=*/false);
+           F != FEnd; ++F) {
+        if (IsAcceptableNonMemberOperatorCandidate(*F, T1, T2, Context)) 
+          AddOverloadCandidate(*F, Args, NumArgs, CandidateSet, 
+                               /*SuppressUserConversions=*/false);
+      }
     }
   }
 
@@ -2476,7 +2513,8 @@
   //      the type of the entity being initialized) is a better
   //      conversion sequence than the standard conversion sequence
   //      from the return type of F2 to the destination type.
-  if (isa<CXXConversionDecl>(Cand1.Function) && 
+  if (Cand1.Function && Cand2.Function && 
+      isa<CXXConversionDecl>(Cand1.Function) && 
       isa<CXXConversionDecl>(Cand2.Function)) {
     switch (CompareStandardConversionSequences(Cand1.FinalConversion,
                                                Cand2.FinalConversion)) {

Modified: cfe/trunk/test/SemaCXX/overloaded-builtin-operators.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/overloaded-builtin-operators.cpp?rev=59583&r1=59582&r2=59583&view=diff

==============================================================================
--- cfe/trunk/test/SemaCXX/overloaded-builtin-operators.cpp (original)
+++ cfe/trunk/test/SemaCXX/overloaded-builtin-operators.cpp Tue Nov 18 21:25:36 2008
@@ -10,10 +10,21 @@
   operator long();
 };
 
+enum E1 { };
+struct Enum1 {
+  operator E1();
+};
+
+enum E2 { };
+struct Enum2 {
+  operator E2();
+};
+
 yes& islong(long);
+yes& islong(unsigned long); // FIXME: shouldn't be needed
 no& islong(int);
 
-void f(Short s, Long l) {
+void f(Short s, Long l, Enum1 e1, Enum2 e2) {
   // C++ [over.built]p12
   (void)static_cast<yes&>(islong(s + l));
   (void)static_cast<no&>(islong(s + s));
@@ -22,6 +33,8 @@
   (void)static_cast<yes&>(islong(s % l));
   (void)static_cast<yes&>(islong(l << s));
   (void)static_cast<no&>(islong(s << l));
+  (void)static_cast<yes&>(islong(e1 % l));
+  // FIXME: should pass (void)static_cast<no&>(islong(e1 % e2));
 }
 
 struct ShortRef {

Modified: cfe/trunk/test/SemaCXX/overloaded-operator.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/overloaded-operator.cpp?rev=59583&r1=59582&r2=59583&view=diff

==============================================================================
--- cfe/trunk/test/SemaCXX/overloaded-operator.cpp (original)
+++ cfe/trunk/test/SemaCXX/overloaded-operator.cpp Tue Nov 18 21:25:36 2008
@@ -48,3 +48,24 @@
     make_A() == z;
   }
 };
+
+enum Enum1 { };
+enum Enum2 { };
+
+struct E1 {
+  E1(Enum1) { }
+};
+
+struct E2 {
+  E2(Enum2);
+};
+
+// C++ [over.match.oper]p3 - enum restriction.
+float& operator==(E1, E2); 
+
+void enum_test(Enum1 enum1, Enum2 enum2, E1 e1, E2 e2) {
+  float &f1 = (e1 == e2);
+  float &f2 = (enum1 == e2); 
+  float &f3 = (e1 == enum2); 
+  float &f4 = (enum1 == enum2);  // expected-error{{non-const reference to type 'float' cannot be initialized with a temporary of type '_Bool'}}
+}





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