r178610 - Fix a crasher in Template Diffing.

[Richard Trieu]

Author: rtrieu
Date: Tue Apr  2 21:22:12 2013
New Revision: 178610

URL: http://llvm.org/viewvc/llvm-project?rev=178610&view=rev
Log:
Fix a crasher in Template Diffing.

When support was added for declaration arguments, the case of variadic
declaration arguments was not supported.  This patch fixes that problem by
not crashing when certain ValueDecl's are null.

Patch by Olivier Goffart!

Modified:
    cfe/trunk/lib/AST/ASTDiagnostic.cpp
    cfe/trunk/test/Misc/diag-template-diffing.cpp

Modified: cfe/trunk/lib/AST/ASTDiagnostic.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTDiagnostic.cpp?rev=178610&r1=178609&r2=178610&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTDiagnostic.cpp (original)
+++ cfe/trunk/lib/AST/ASTDiagnostic.cpp Tue Apr  2 21:22:12 2013
@@ -944,7 +944,8 @@ class TemplateDiff {
           if (!HasToValueDecl && ToExpr)
             ToValueDecl = GetValueDecl(ToIter, ToExpr);
           Tree.SetNode(FromValueDecl, ToValueDecl);
-          Tree.SetSame(FromValueDecl->getCanonicalDecl() ==
+          Tree.SetSame(FromValueDecl && ToValueDecl &&
+                       FromValueDecl->getCanonicalDecl() ==
                        ToValueDecl->getCanonicalDecl());
           Tree.SetDefault(FromIter.isEnd() && FromValueDecl,
                           ToIter.isEnd() && ToValueDecl);

Modified: cfe/trunk/test/Misc/diag-template-diffing.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Misc/diag-template-diffing.cpp?rev=178610&r1=178609&r2=178610&view=diff
==============================================================================
--- cfe/trunk/test/Misc/diag-template-diffing.cpp (original)
+++ cfe/trunk/test/Misc/diag-template-diffing.cpp Tue Apr  2 21:22:12 2013
@@ -958,6 +958,45 @@ namespace DependentDefault {
   }
 }
 
+namespace VariadicDefault {
+  int i1, i2, i3;
+  template <int = 5, int...> struct A {};
+  template <int& = i1, int& ...> struct B {};
+  template <typename = void, typename...> struct C {};
+
+  void test() {
+    A<> a1;
+    A<5, 6, 7> a2;
+    A<1, 2> a3;
+    a2 = a1;
+    // CHECK-ELIDE-NOTREE: no viable overloaded '='
+    // CHECK-ELIDE-NOTREE: no known conversion from 'A<[...], (no argument), (no argument)>' to 'A<[...], 6, 7>'
+    a3 = a1;
+    // CHECK-ELIDE-NOTREE: no viable overloaded '='
+    // CHECK-ELIDE-NOTREE: no known conversion from 'A<(default) 5, (no argument)>' to 'A<1, 2>'
+
+    B<> b1;
+    B<i1, i2, i3> b2;
+    B<i2, i3> b3;
+    b2 = b1;
+    // CHECK-ELIDE-NOTREE: no viable overloaded '='
+    // CHECK-ELIDE-NOTREE: no known conversion from 'B<[...], (no argument), (no argument)>' to 'B<[...], i2, i3>'
+    b3 = b1;
+    // CHECK-ELIDE-NOTREE: no viable overloaded '='
+    // CHECK-ELIDE-NOTREE: no known conversion from 'B<(default) i1, (no argument)>' to 'B<i2, i3>'
+
+    C<> c1;
+    C<void, void> c2;
+    C<char, char> c3;
+    c2 = c1;
+    // CHECK-ELIDE-NOTREE: no viable overloaded '='
+    // CHECK-ELIDE-NOTREE: no known conversion from 'C<[...], (no argument)>' to 'C<[...], void>'
+    c3 = c1;
+    // CHECK-ELIDE-NOTREE: no viable overloaded '='
+    // CHECK-ELIDE-NOTREE: no known conversion from 'C<(default) void, (no argument)>' to 'C<char, char>'
+  }
+}
+
 // CHECK-ELIDE-NOTREE: {{[0-9]*}} errors generated.
 // CHECK-NOELIDE-NOTREE: {{[0-9]*}} errors generated.
 // CHECK-ELIDE-TREE: {{[0-9]*}} errors generated.