Convert SemaTemplate*.cpp to pass a callback object to CorrectTypo.

The change to SemaTemplateVariadic.cpp improves the typo correction
results in certain situations, while the change to SemaTemplate.cpp
does not change existing behavior.

llvm-svn: 148155

clang/lib/Sema/SemaTemplate.cpp

@@ -301,10 +301,15 @@ void Sema::LookupTemplateName(LookupResult &Found,
     // If we did not find any names, attempt to correct any typos.
     DeclarationName Name = Found.getLookupName();
     Found.clear();
+    // Simple filter callback that, for keywords, only accepts the C++ *_cast
+    CorrectionCandidateCallback FilterCCC;
+    FilterCCC.WantTypeSpecifiers = false;
+    FilterCCC.WantExpressionKeywords = false;
+    FilterCCC.WantRemainingKeywords = false;
+    FilterCCC.WantCXXNamedCasts = true;
     if (TypoCorrection Corrected = CorrectTypo(Found.getLookupNameInfo(),
                                                Found.getLookupKind(), S, &SS,
-                                               LookupCtx, false,
-                                               CTC_CXXCasts)) {
+                                               &FilterCCC, LookupCtx)) {
       Found.setLookupName(Corrected.getCorrection());
       if (Corrected.getCorrectionDecl())
         Found.addDecl(Corrected.getCorrectionDecl());

clang/lib/Sema/SemaTemplateVariadic.cpp

@@ -708,6 +708,19 @@ bool Sema::containsUnexpandedParameterPacks(Declarator &D) {
   return false;
 }
 
+namespace {
+
+// Callback to only accept typo corrections that refer to parameter packs.
+class ParameterPackValidatorCCC : public CorrectionCandidateCallback {
+ public:
+  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
+    NamedDecl *ND = candidate.getCorrectionDecl();
+    return ND && ND->isParameterPack();
+  }
+};
+
+}
+
 /// \brief Called when an expression computing the size of a parameter pack
 /// is parsed.
 ///
@@ -733,6 +746,7 @@ ExprResult Sema::ActOnSizeofParameterPackExpr(Scope *S,
   LookupName(R, S);
   
   NamedDecl *ParameterPack = 0;
+  ParameterPackValidatorCCC Validator;
   switch (R.getResultKind()) {
   case LookupResult::Found:
     ParameterPack = R.getFoundDecl();
@@ -741,19 +755,16 @@ ExprResult Sema::ActOnSizeofParameterPackExpr(Scope *S,
   case LookupResult::NotFound:
   case LookupResult::NotFoundInCurrentInstantiation:
     if (TypoCorrection Corrected = CorrectTypo(R.getLookupNameInfo(),
-                                               R.getLookupKind(), S, 0, 0,
-                                               false, CTC_NoKeywords)) {
-      if (NamedDecl *CorrectedResult = Corrected.getCorrectionDecl())
-        if (CorrectedResult->isParameterPack()) {
-          std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOptions()));
-          ParameterPack = CorrectedResult;
-          Diag(NameLoc, diag::err_sizeof_pack_no_pack_name_suggest)
-            << &Name << CorrectedQuotedStr
-            << FixItHint::CreateReplacement(
-                NameLoc, Corrected.getAsString(getLangOptions()));
-          Diag(ParameterPack->getLocation(), diag::note_parameter_pack_here)
-            << CorrectedQuotedStr;
-        }
+                                               R.getLookupKind(), S, 0,
+                                               &Validator)) {
+      std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOptions()));
+      ParameterPack = Corrected.getCorrectionDecl();
+      Diag(NameLoc, diag::err_sizeof_pack_no_pack_name_suggest)
+        << &Name << CorrectedQuotedStr
+        << FixItHint::CreateReplacement(
+            NameLoc, Corrected.getAsString(getLangOptions()));
+      Diag(ParameterPack->getLocation(), diag::note_parameter_pack_here)
+        << CorrectedQuotedStr;
     }
       
   case LookupResult::FoundOverloaded:

clang/test/SemaCXX/typo-correction.cpp

@@ -41,6 +41,8 @@ struct Derived : public BaseType { // expected-note {{base class 'BaseType' spec
   Derived() : basetype() {} // expected-error{{initializer 'basetype' does not name a non-static data member or base class; did you mean the base class 'BaseType'?}}
 };
 
+// Test the improvement from passing a callback object to CorrectTypo in
+// the helper function LookupMemberExprInRecord.
 int get_type(struct Derived *st) {
   return st->Base_Type; // expected-error{{no member named 'Base_Type' in 'Derived'; did you mean 'base_type'?}}
 }
@@ -64,10 +66,17 @@ struct st {
 };
 st var = { .fielda = 0.0 }; // expected-error{{field designator 'fielda' does not refer to any field in type 'st'; did you mean 'FieldA'?}}
 
-// Test the improvement from passing a  callback object to CorrectTypo in
+// Test the improvement from passing a callback object to CorrectTypo in
 // Sema::BuildCXXNestedNameSpecifier.
 typedef char* another_str;
 namespace AnotherStd { // expected-note{{'AnotherStd' declared here}}
   class string {};
 }
 another_std::string str; // expected-error{{use of undeclared identifier 'another_std'; did you mean 'AnotherStd'?}}
+
+// Test the improvement from passing a callback object to CorrectTypo in
+// Sema::ActOnSizeofParameterPackExpr.
+char* TireNames;
+template<typename ...TypeNames> struct count { // expected-note{{parameter pack 'TypeNames' declared here}}
+  static const unsigned value = sizeof...(TyreNames); // expected-error{{'TyreNames' does not refer to the name of a parameter pack; did you mean 'TypeNames'?}}
+};