Add a new conversion rank to classify conversions between complex and scalar

types. Rank these conversions below other conversions. This allows overload
resolution when the only distinction is between a complex and scalar type. It
also brings the complex overload resolutin in line with GCC's.

llvm-svn: 97128

2 files changed, 15 insertions, 14 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index ffda69dcc83..7208b90939a 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -80,7 +80,7 @@ ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) {
     ICR_Conversion,
     ICR_Conversion,
     ICR_Conversion,
-    ICR_Conversion
+    ICR_Complex_Real_Conversion
   };
   return Rank[(int)Kind];
 }
@@ -669,14 +669,19 @@ Sema::IsStandardConversion(Expr* From, QualType ToType,
     // Integral conversions (C++ 4.7).
     SCS.Second = ICK_Integral_Conversion;
     FromType = ToType.getUnqualifiedType();
-  } else if (FromType->isFloatingType() && ToType->isFloatingType()) {
-    // Floating point conversions (C++ 4.8).
-    SCS.Second = ICK_Floating_Conversion;
-    FromType = ToType.getUnqualifiedType();
   } else if (FromType->isComplexType() && ToType->isComplexType()) {
     // Complex conversions (C99 6.3.1.6)
     SCS.Second = ICK_Complex_Conversion;
     FromType = ToType.getUnqualifiedType();
+  } else if ((FromType->isComplexType() && ToType->isArithmeticType()) ||
+             (ToType->isComplexType() && FromType->isArithmeticType())) {
+    // Complex-real conversions (C99 6.3.1.7)
+    SCS.Second = ICK_Complex_Real;
+    FromType = ToType.getUnqualifiedType();
+  } else if (FromType->isFloatingType() && ToType->isFloatingType()) {
+    // Floating point conversions (C++ 4.8).
+    SCS.Second = ICK_Floating_Conversion;
+    FromType = ToType.getUnqualifiedType();
   } else if ((FromType->isFloatingType() &&
               ToType->isIntegralType() && (!ToType->isBooleanType() &&
                                            !ToType->isEnumeralType())) ||
@@ -685,11 +690,6 @@ Sema::IsStandardConversion(Expr* From, QualType ToType,
     // Floating-integral conversions (C++ 4.9).
     SCS.Second = ICK_Floating_Integral;
     FromType = ToType.getUnqualifiedType();
-  } else if ((FromType->isComplexType() && ToType->isArithmeticType()) ||
-             (ToType->isComplexType() && FromType->isArithmeticType())) {
-    // Complex-real conversions (C99 6.3.1.7)
-    SCS.Second = ICK_Complex_Real;
-    FromType = ToType.getUnqualifiedType();
   } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution,
                                  FromType, IncompatibleObjC)) {
     // Pointer conversions (C++ 4.10).
diff --git a/clang/lib/Sema/SemaOverload.h b/clang/lib/Sema/SemaOverload.h
index 3b06e7a8dfb..62b096f703a 100644
--- a/clang/lib/Sema/SemaOverload.h
+++ b/clang/lib/Sema/SemaOverload.h
@@ -54,12 +54,12 @@ namespace clang {
     ICK_Floating_Conversion,   ///< Floating point conversions (C++ 4.8)
     ICK_Complex_Conversion,    ///< Complex conversions (C99 6.3.1.6)
     ICK_Floating_Integral,     ///< Floating-integral conversions (C++ 4.9)
-    ICK_Complex_Real,          ///< Complex-real conversions (C99 6.3.1.7)
     ICK_Pointer_Conversion,    ///< Pointer conversions (C++ 4.10)
     ICK_Pointer_Member,        ///< Pointer-to-member conversions (C++ 4.11)
     ICK_Boolean_Conversion,    ///< Boolean conversions (C++ 4.12)
     ICK_Compatible_Conversion, ///< Conversions between compatible types in C99
     ICK_Derived_To_Base,       ///< Derived-to-base (C++ [over.best.ics])
+    ICK_Complex_Real,          ///< Complex-real conversions (C99 6.3.1.7)
     ICK_Num_Conversion_Kinds   ///< The number of conversion kinds
   };
 
@@ -83,9 +83,10 @@ namespace clang {
   /// 13.3.3.1.1) and are listed such that better conversion ranks
   /// have smaller values.
   enum ImplicitConversionRank {
-    ICR_Exact_Match = 0, ///< Exact Match
-    ICR_Promotion,       ///< Promotion
-    ICR_Conversion       ///< Conversion
+    ICR_Exact_Match = 0,        ///< Exact Match
+    ICR_Promotion,              ///< Promotion
+    ICR_Conversion,             ///< Conversion
+    ICR_Complex_Real_Conversion ///< Complex <-> Real conversion
   };
 
   ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind);