Improve overloaded function handling in the typo correction code.

Change TypoCorrection to store a set of NamedDecls instead of a single
NamedDecl. Also add initial support for performing function overload
resolution to Sema::DiagnoseEmptyLookup.

llvm-svn: 136807

3 files changed, 64 insertions, 11 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 55e04b79de0..6ace3e92e60 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -1364,7 +1364,8 @@ Sema::DecomposeUnqualifiedId(const UnqualifiedId &Id,
 ///
 /// \return false if new lookup candidates were found
 bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
-                               CorrectTypoContext CTC) {
+                               CorrectTypoContext CTC, Expr **Args,
+                               unsigned NumArgs) {
   DeclarationName Name = R.getLookupName();
 
   unsigned diagnostic = diag::err_undeclared_var_use;
@@ -1450,6 +1451,27 @@ bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
     R.setLookupName(Corrected.getCorrection());
 
     if (NamedDecl *ND = Corrected.getCorrectionDecl()) {
+      if (Corrected.isOverloaded()) {
+        OverloadCandidateSet OCS(R.getNameLoc());
+        OverloadCandidateSet::iterator Best;
+        for (TypoCorrection::decl_iterator CD = Corrected.begin(),
+                                        CDEnd = Corrected.end();
+             CD != CDEnd; ++CD) {
+          if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*CD))
+            AddOverloadCandidate(FD, DeclAccessPair::make(*CD, AS_none),
+                                 Args, NumArgs, OCS);
+          // TODO: Handle FunctionTemplateDecl and other Decl types that
+          // support overloading and could be corrected by CorrectTypo.
+        }
+        switch (OCS.BestViableFunction(*this, R.getNameLoc(), Best)) {
+          case OR_Success:
+            ND = Best->Function;
+            break;
+          default:
+            // Don't try to recover; it won't work.
+            return true;
+        }
+      }
       R.addDecl(ND);
       if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
         if (SS.isEmpty())
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index c5ba95a1f4e..240eb5f1bf7 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -3020,7 +3020,7 @@ public:
   void FoundName(StringRef Name);
   void addKeywordResult(StringRef Keyword);
   void addName(StringRef Name, NamedDecl *ND, unsigned Distance,
-               NestedNameSpecifier *NNS=NULL);
+               NestedNameSpecifier *NNS=NULL, bool isKeyword=false);
   void addCorrection(TypoCorrection Correction);
 
   typedef TypoResultsMap::iterator result_iterator;
@@ -3099,15 +3099,17 @@ void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
     return;
   }
 
-  addName(Keyword, TypoCorrection::KeywordDecl(), ED);
+  addName(Keyword, NULL, ED, NULL, true);
 }
 
 void TypoCorrectionConsumer::addName(StringRef Name,
                                      NamedDecl *ND,
                                      unsigned Distance,
-                                     NestedNameSpecifier *NNS) {
-  addCorrection(TypoCorrection(&SemaRef.Context.Idents.get(Name),
-                               ND, NNS, Distance));
+                                     NestedNameSpecifier *NNS,
+                                     bool isKeyword) {
+  TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, Distance);
+  if (isKeyword) TC.makeKeyword();
+  addCorrection(TC);
 }
 
 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
@@ -3677,12 +3679,19 @@ TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
         // We don't deal with ambiguities.
         return TypoCorrection();
 
+      case LookupResult::FoundOverloaded: {
+        // Store all of the Decls for overloaded symbols
+        for (LookupResult::iterator TRD = TmpRes.begin(),
+                                 TRDEnd = TmpRes.end();
+             TRD != TRDEnd; ++TRD)
+          I->second.addCorrectionDecl(*TRD);
+        ++I;
+        break;
+      }
+
       case LookupResult::Found:
-      case LookupResult::FoundOverloaded:
       case LookupResult::FoundUnresolvedValue:
         I->second.setCorrectionDecl(TmpRes.getAsSingle<NamedDecl>());
-        // FIXME: This sets the CorrectionDecl to NULL for overloaded functions.
-        // It would be nice to find the right one with overload resolution.
         ++I;
         break;
       }
@@ -3718,11 +3727,20 @@ TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
 
           switch (TmpRes.getResultKind()) {
           case LookupResult::Found:
-          case LookupResult::FoundOverloaded:
           case LookupResult::FoundUnresolvedValue:
             Consumer.addName((*QRI)->getName(), TmpRes.getAsSingle<NamedDecl>(),
                              QualifiedED, NI->NameSpecifier);
             break;
+          case LookupResult::FoundOverloaded: {
+            TypoCorrection corr(&Context.Idents.get((*QRI)->getName()), NULL,
+                                NI->NameSpecifier, QualifiedED);
+            for (LookupResult::iterator TRD = TmpRes.begin(),
+                                     TRDEnd = TmpRes.end();
+                 TRD != TRDEnd; ++TRD)
+              corr.addCorrectionDecl(*TRD);
+            Consumer.addCorrection(corr);
+            break;
+          }
           case LookupResult::NotFound:
           case LookupResult::NotFoundInCurrentInstantiation:
           case LookupResult::Ambiguous:
@@ -3802,6 +3820,18 @@ TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
   return TypoCorrection();
 }
 
+void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
+  if (!CDecl) return;
+
+  if (isKeyword())
+    CorrectionDecls.clear();
+
+  CorrectionDecls.push_back(CDecl);
+
+  if (!CorrectionName)
+    CorrectionName = CDecl->getDeclName();
+}
+
 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
   if (CorrectionNameSpec) {
     std::string tmpBuffer;
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 79aa305b86f..712720bf9e8 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -8220,7 +8220,8 @@ BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
   if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
                               ExplicitTemplateArgs, Args, NumArgs) &&
       (!EmptyLookup ||
-       SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)))
+       SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression,
+                                   Args, NumArgs)))
     return ExprError();
 
   assert(!R.empty() && "lookup results empty despite recovery");