From: Richard Trieu <rtrieu@google.com>
Date: Wed, 3 Apr 2013 02:22:12 +0000 (+0000)
Subject: Fix a crasher in Template Diffing.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=fa3d2758653113cd2b5fff06f8ff22eeb669c044;p=clang

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!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178610 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ASTDiagnostic.cpp b/lib/AST/ASTDiagnostic.cpp
index 419152de04..c2c24925eb 100644
--- a/lib/AST/ASTDiagnostic.cpp
+++ b/lib/AST/ASTDiagnostic.cpp
@@ -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);
diff --git a/test/Misc/diag-template-diffing.cpp b/test/Misc/diag-template-diffing.cpp
index fd331139a8..f27f8b67e2 100644
--- a/test/Misc/diag-template-diffing.cpp
+++ b/test/Misc/diag-template-diffing.cpp
@@ -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.