Robustify PreprocessingRecord slightly, by only creating macro

instantiations when we have the corresponding macro definition and by
removing macro definition information from our table when the macro is
undefined. 


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@99004 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Lex/PreprocessingRecord.h

@@ -253,10 +253,11 @@ namespace clang {
     
     /// \brief Retrieve the macro definition that corresponds to the given
     /// \c MacroInfo.
-    MacroDefinition *findMacroDefinition(MacroInfo *MI);
+    MacroDefinition *findMacroDefinition(const MacroInfo *MI);
     
     virtual void MacroExpands(const Token &Id, const MacroInfo* MI);
     virtual void MacroDefined(const IdentifierInfo *II, const MacroInfo *MI);
+    virtual void MacroUndefined(const IdentifierInfo *II, const MacroInfo *MI);
   };
 } // end namespace clang
 

lib/Lex/PreprocessingRecord.cpp

@@ -92,7 +92,7 @@ void PreprocessingRecord::RegisterMacroDefinition(MacroInfo *Macro,
   MacroDefinitions[Macro] = MD;
 }
 
-MacroDefinition *PreprocessingRecord::findMacroDefinition(MacroInfo *MI) {
+MacroDefinition *PreprocessingRecord::findMacroDefinition(const MacroInfo *MI) {
   llvm::DenseMap<const MacroInfo *, MacroDefinition *>::iterator Pos
     = MacroDefinitions.find(MI);
   if (Pos == MacroDefinitions.end())
@@ -102,10 +102,11 @@ MacroDefinition *PreprocessingRecord::findMacroDefinition(MacroInfo *MI) {
 }
 
 void PreprocessingRecord::MacroExpands(const Token &Id, const MacroInfo* MI) {
-  PreprocessedEntities.push_back(
+  if (MacroDefinition *Def = findMacroDefinition(MI))
+    PreprocessedEntities.push_back(
                        new (*this) MacroInstantiation(Id.getIdentifierInfo(),
                                                       Id.getLocation(),
-                                                      MacroDefinitions[MI]));
+                                                      Def));
 }
 
 void PreprocessingRecord::MacroDefined(const IdentifierInfo *II, 
@@ -117,3 +118,11 @@ void PreprocessingRecord::MacroDefined(const IdentifierInfo *II,
   PreprocessedEntities.push_back(Def);
 }
 
+void PreprocessingRecord::MacroUndefined(const IdentifierInfo *II, 
+                                         const MacroInfo *MI) {
+  llvm::DenseMap<const MacroInfo *, MacroDefinition *>::iterator Pos
+    = MacroDefinitions.find(MI);
+  if (Pos != MacroDefinitions.end())
+    MacroDefinitions.erase(Pos);
+}
+

test/Index/c-index-getCursor-test.m

@@ -57,6 +57,7 @@ int main (int argc, const char * argv[]) {
 void f() {
    int CONCAT(my,_var);
 }
+#undef CONCAT
 
 // CHECK: [1:1 - 3:1] Invalid Cursor => NoDeclFound
 // CHECK: [3:1 - 7:1] ObjCInterfaceDecl=Foo:3:12