r220588 - Itanium ABI: Template template parameters are usable as substitutions

[David Majnemer]

Author: majnemer
Date: Fri Oct 24 15:22:57 2014
New Revision: 220588

URL: http://llvm.org/viewvc/llvm-project?rev=220588&view=rev
Log:
Itanium ABI: Template template parameters are usable as substitutions

Template template parameters weren't added to the list of substitutions.
This would make the substitution map contain inaccurate mappings,
leading to Clang violating the Itanium ABI and breaking compatibility
with GCC.

This fixes PR21351.

Differential Revision: http://reviews.llvm.org/D5959

Modified:
    cfe/trunk/lib/AST/ItaniumMangle.cpp
    cfe/trunk/test/CodeGenCXX/mangle.cpp

Modified: cfe/trunk/lib/AST/ItaniumMangle.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ItaniumMangle.cpp?rev=220588&r1=220587&r2=220588&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ItaniumMangle.cpp (original)
+++ cfe/trunk/lib/AST/ItaniumMangle.cpp Fri Oct 24 15:22:57 2014
@@ -637,13 +637,11 @@ void CXXNameMangler::mangleUnscopedTempl
     return;
 
   // <template-template-param> ::= <template-param>
-  if (const TemplateTemplateParmDecl *TTP
-                                     = dyn_cast<TemplateTemplateParmDecl>(ND)) {
+  if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(ND))
     mangleTemplateParameter(TTP->getIndex());
-    return;
-  }
+  else
+    mangleUnscopedName(ND->getTemplatedDecl());
 
-  mangleUnscopedName(ND->getTemplatedDecl());
   addSubstitution(ND);
 }
 
@@ -1563,14 +1561,13 @@ void CXXNameMangler::mangleTemplatePrefi
     return;
 
   // <template-template-param> ::= <template-param>
-  if (const TemplateTemplateParmDecl *TTP
-                                     = dyn_cast<TemplateTemplateParmDecl>(ND)) {
+  if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(ND)) {
     mangleTemplateParameter(TTP->getIndex());
-    return;
+  } else {
+    manglePrefix(getEffectiveDeclContext(ND), NoFunction);
+    mangleUnqualifiedName(ND->getTemplatedDecl());
   }
 
-  manglePrefix(getEffectiveDeclContext(ND), NoFunction);
-  mangleUnqualifiedName(ND->getTemplatedDecl());
   addSubstitution(ND);
 }
 

Modified: cfe/trunk/test/CodeGenCXX/mangle.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/mangle.cpp?rev=220588&r1=220587&r2=220588&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/mangle.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/mangle.cpp Fri Oct 24 15:22:57 2014
@@ -991,3 +991,25 @@ namespace test48 {
   template void f<S>(S::u *);
   // CHECK-LABEL: define weak_odr void @_ZN6test481fINS_1SEEEvPTuNT_1uE(%"union.test48::S::u"*)
 }
+
+namespace test49 {
+  template <int>
+  struct S {};
+
+  template <template <int> class T>
+  T<3> fin(T<3>);
+
+  auto v = fin<S>;
+  // CHECK-LABEL: declare void @_ZN6test493finINS_1SEEET_ILi3EES3_()
+}
+
+namespace test50 {
+  template <int>
+  struct S {};
+
+  template <template <int> class T>
+  T<3> fin(T<4>);
+
+  auto v = fin<S>;
+  // CHECK-LABEL: declare void @_ZN6test503finINS_1SEEET_ILi3EES2_ILi4EE()
+}