Make the construction of the code-completion string for a function
template smarter, by taking into account which function template
parameters are deducible from the call arguments. For example,

  template<typename RandomAccessIterator>
  void sort(RandomAccessIterator first, RandomAccessIterator last);

will have a code-completion string like

  sort({RandomAccessIterator first}, {RandomAccessIterator last})

since the template argument for its template parameter is
deducible. On the other hand,

  template<class X, class Y>
  X* dyn_cast(Y *Val);

will have a code-completion string like

  dyn_cast<{class X}>({Y *Val})

since the template type parameter X is not deducible from the function
call.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@82306 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 24246e5..5a5d63e 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -2199,3 +2199,18 @@
   for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
     ::MarkUsedTemplateParameters(*this, TemplateArgs[I], OnlyDeduced, Used);
 }
+
+/// \brief Marks all of the template parameters that will be deduced by a
+/// call to the given function template.
+void Sema::MarkDeducedTemplateParameters(FunctionTemplateDecl *FunctionTemplate,
+                                         llvm::SmallVectorImpl<bool> &Deduced) {
+  TemplateParameterList *TemplateParams 
+    = FunctionTemplate->getTemplateParameters();
+  Deduced.clear();
+  Deduced.resize(TemplateParams->size());
+  
+  FunctionDecl *Function = FunctionTemplate->getTemplatedDecl();
+  for (unsigned I = 0, N = Function->getNumParams(); I != N; ++I)
+    ::MarkUsedTemplateParameters(*this, Function->getParamDecl(I)->getType(),
+                                 true, Deduced);
+}