When there are extra or missing template parameter lists in a template

definition, we're likely going to end up breaking the invariants of
the template system, e.g., that the depths of template parameter lists
match up with the nesting template of the template. So, make sure we
mark such ill-formed declarations as invalid or don't even build them
at all.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@108372 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 3 deletions

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 7cc4317845..f121954eed 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -1233,7 +1233,8 @@ Sema::MatchTemplateParametersToScopeSpecifier(SourceLocation DeclStartLoc,
                                           TemplateParameterList **ParamLists,
                                               unsigned NumParamLists,
                                               bool IsFriend,
-                                              bool &IsExplicitSpecialization) {
+                                              bool &IsExplicitSpecialization,
+                                              bool &Invalid) {
   IsExplicitSpecialization = false;
   
   // Find the template-ids that occur within the nested-name-specifier. These
@@ -1311,6 +1312,7 @@ Sema::MatchTemplateParametersToScopeSpecifier(SourceLocation DeclStartLoc,
              diag::err_template_spec_needs_template_parameters)
           << TemplateId
           << SS.getRange();
+        Invalid = true;
       } else {
         Diag(SS.getRange().getBegin(), diag::err_template_spec_needs_header)
           << SS.getRange()
@@ -1373,7 +1375,13 @@ Sema::MatchTemplateParametersToScopeSpecifier(SourceLocation DeclStartLoc,
           << ExplicitSpecializationsInSpecifier.back();
         ExplicitSpecializationsInSpecifier.pop_back();
       }
-        
+
+      // We have a template parameter list with no corresponding scope, which 
+      // means that the resulting template declaration can't be instantiated
+      // properly (we'll end up with dependent nodes when we shouldn't).
+      if (!isExplicitSpecHeader)
+        Invalid = true;
+      
       ++Idx;
     }
   }
@@ -3622,12 +3630,17 @@ Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
   // template.
   // FIXME: We probably shouldn't complain about these headers for
   // friend declarations.
+  bool Invalid = false;
   TemplateParameterList *TemplateParams
     = MatchTemplateParametersToScopeSpecifier(TemplateNameLoc, SS,
                         (TemplateParameterList**)TemplateParameterLists.get(),
                                               TemplateParameterLists.size(),
                                               TUK == TUK_Friend,
-                                              isExplicitSpecialization);
+                                              isExplicitSpecialization,
+                                              Invalid);
+  if (Invalid)
+    return true;
+    
   unsigned NumMatchedTemplateParamLists = TemplateParameterLists.size();
   if (TemplateParams)
     --NumMatchedTemplateParamLists;