Add another keyword-selection flag to CorrectionCandidateCallback.

The new flag, WantFunctionLikeCasts, covers a subset of the keywords
covered by WantTypeSpecifiers that can be used in casts that look like
function calls, e.g. "return long(5);", while excluding the keywords
like "enum" and "const" that would be included when WantTypeSpecifiers
is true but cannot be used in something that looks like a function call.

llvm-svn: 214109

clang/include/clang/Sema/TypoCorrection.h

@@ -249,9 +249,9 @@ public:
 
   CorrectionCandidateCallback()
       : WantTypeSpecifiers(true), WantExpressionKeywords(true),
-        WantCXXNamedCasts(true), WantRemainingKeywords(true),
-        WantObjCSuper(false), IsObjCIvarLookup(false),
-        IsAddressOfOperand(false) {}
+        WantCXXNamedCasts(true), WantFunctionLikeCasts(true),
+        WantRemainingKeywords(true), WantObjCSuper(false),
+        IsObjCIvarLookup(false), IsAddressOfOperand(false) {}
 
   virtual ~CorrectionCandidateCallback() {}
 
@@ -277,11 +277,13 @@ public:
     return ValidateCandidate(candidate) ? 0 : InvalidDistance;
   }
 
-  // Flags for context-dependent keywords.
+  // Flags for context-dependent keywords. WantFunctionLikeCasts is only
+  // used/meaningful when WantCXXNamedCasts is false.
   // TODO: Expand these to apply to non-keywords or possibly remove them.
   bool WantTypeSpecifiers;
   bool WantExpressionKeywords;
   bool WantCXXNamedCasts;
+  bool WantFunctionLikeCasts;
   bool WantRemainingKeywords;
   bool WantObjCSuper;
   // Temporary hack for the one case where a CorrectTypoContext enum is used
@@ -325,6 +327,7 @@ public:
     WantTypeSpecifiers = false;
     WantExpressionKeywords = false;
     WantCXXNamedCasts = false;
+    WantFunctionLikeCasts = false;
     WantRemainingKeywords = false;
   }
 

clang/lib/Sema/SemaLookup.cpp

@@ -3972,6 +3972,13 @@ static void AddKeywordsToConsumer(Sema &SemaRef,
 
     if (SemaRef.getLangOpts().GNUMode)
       Consumer.addKeywordResult("typeof");
+  } else if (CCC.WantFunctionLikeCasts) {
+    static const char *const CastableTypeSpecs[] = {
+      "char", "double", "float", "int", "long", "short",
+      "signed", "unsigned", "void"
+    };
+    for (auto *kw : CastableTypeSpecs)
+      Consumer.addKeywordResult(kw);
   }
 
   if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
@@ -4461,7 +4468,8 @@ FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
                                              MemberExpr *ME)
     : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
       CurContext(SemaRef.CurContext), MemberFn(ME) {
-  WantTypeSpecifiers = SemaRef.getLangOpts().CPlusPlus;
+  WantTypeSpecifiers = false;
+  WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
   WantRemainingKeywords = false;
 }
 

clang/test/SemaCXX/typo-correction-pt2.cpp

@@ -300,3 +300,12 @@ namespace PR19681 {
     (void)static_cast<void(TypoB::*)(int)>(&TypoA::private_memfn);  // expected-error{{no member named 'private_memfn' in 'PR19681::TypoA'; did you mean '::PR19681::TypoB::private_memfn'?}}
   }
 }
+
+namespace testWantFunctionLikeCasts {
+  long test(bool a) {
+    if (a)
+      return struc(5.7);  // expected-error-re {{use of undeclared identifier 'struc'{{$}}}}
+    else
+      return lon(8.0);  // expected-error {{use of undeclared identifier 'lon'; did you mean 'long'?}}
+  }
+}