[cfe-commits] r117983 - in /cfe/trunk: lib/Sema/SemaTemplateDeduction.cpp test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp

[Douglas Gregor]

Author: dgregor
Date: Mon Nov  1 19:02:34 2010
New Revision: 117983

URL: http://llvm.org/viewvc/llvm-project?rev=117983&view=rev
Log:
When performing template argument deduction against a template-id,
only keep deduction results for successful deductions, so that they
can be compared against each other. Fixes PR8462, from Richard Smith!

Modified:
    cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp
    cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp

Modified: cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp?rev=117983&r1=117982&r2=117983&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp Mon Nov  1 19:02:34 2010
@@ -721,6 +721,8 @@
           llvm::SmallVector<const RecordType *, 8> ToVisit;
           ToVisit.push_back(RecordT);
           bool Successful = false;
+          llvm::SmallVectorImpl<DeducedTemplateArgument> DeducedOrig(0);
+          DeducedOrig = Deduced;
           while (!ToVisit.empty()) {
             // Retrieve the next class in the inheritance hierarchy.
             const RecordType *NextT = ToVisit.back();
@@ -738,9 +740,14 @@
                                           QualType(NextT, 0), Info, Deduced);
 
               // If template argument deduction for this base was successful,
-              // note that we had some success.
-              if (BaseResult == Sema::TDK_Success)
+              // note that we had some success. Otherwise, ignore any deductions
+              // from this base class.
+              if (BaseResult == Sema::TDK_Success) {
                 Successful = true;
+                DeducedOrig = Deduced;
+              }
+              else
+                Deduced = DeducedOrig;
             }
 
             // Visit base classes

Modified: cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp?rev=117983&r1=117982&r2=117983&view=diff
==============================================================================
--- cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp (original)
+++ cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp Mon Nov  1 19:02:34 2010
@@ -101,3 +101,25 @@
   C<int, 1> *ci3c = f4c(&g);
   int       *ip1 = f4c(&f);
 }
+
+// PR8462
+namespace N {
+  struct T0;
+  struct T1;
+
+  template<typename X, typename Y> struct B {};
+
+  struct J : B<T0,T0> {};
+  struct K : B<T1,T1> {};
+
+  struct D : J, K {};
+
+  template<typename X, typename Y> void F(B<Y,X>);
+
+  void test()
+  {
+    D d; 
+    N::F<T0>(d); // Fails
+    N::F<T1>(d); // OK
+  }
+}