Push location through the MacroUndefined PPCallback and use it to print #undefs in -dD mode. (PR7818)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110523 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Lex/PPCallbacks.h

@@ -89,7 +89,8 @@ public:
 
   /// MacroUndefined - This hook is called whenever a macro #undef is seen.
   /// MI is released immediately following this callback.
-  virtual void MacroUndefined(const IdentifierInfo *II, const MacroInfo *MI) {
+  virtual void MacroUndefined(SourceLocation Loc, const IdentifierInfo *II,
+                              const MacroInfo *MI) {
   }
 };
 
@@ -149,9 +150,10 @@ public:
     Second->MacroDefined(II, MI);
   }
 
-  virtual void MacroUndefined(const IdentifierInfo *II, const MacroInfo *MI) {
-    First->MacroUndefined(II, MI);
-    Second->MacroUndefined(II, MI);
+  virtual void MacroUndefined(SourceLocation Loc, const IdentifierInfo *II,
+                              const MacroInfo *MI) {
+    First->MacroUndefined(Loc, II, MI);
+    Second->MacroUndefined(Loc, II, MI);
   }
 };
 

include/clang/Lex/PreprocessingRecord.h

@@ -257,7 +257,8 @@ namespace clang {
     
     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);
+    virtual void MacroUndefined(SourceLocation Loc, const IdentifierInfo *II,
+                                const MacroInfo *MI);
   };
 } // end namespace clang
 

lib/Frontend/PrintPreprocessedOutput.cpp

@@ -137,6 +137,9 @@ public:
   /// MacroDefined - This hook is called whenever a macro definition is seen.
   void MacroDefined(const IdentifierInfo *II, const MacroInfo *MI);
 
+  /// MacroUndefined - This hook is called whenever a macro #undef is seen.
+  void MacroUndefined(SourceLocation Loc, const IdentifierInfo *II,
+                      const MacroInfo *MI);
 };
 }  // end anonymous namespace
 
@@ -280,6 +283,16 @@ void PrintPPOutputPPCallbacks::MacroDefined(const IdentifierInfo *II,
   EmittedMacroOnThisLine = true;
 }
 
+void PrintPPOutputPPCallbacks::MacroUndefined(SourceLocation Loc,
+                                              const IdentifierInfo *II,
+                                              const MacroInfo *MI) {
+  // Only print out macro definitions in -dD mode.
+  if (!DumpDefines) return;
+
+  MoveToLine(Loc);
+  OS << "#undef " << II->getName();
+  EmittedMacroOnThisLine = true;
+}
 
 void PrintPPOutputPPCallbacks::PragmaComment(SourceLocation Loc,
                                              const IdentifierInfo *Kind,

lib/Lex/PPDirectives.cpp

@@ -1508,7 +1508,8 @@ void Preprocessor::HandleUndefDirective(Token &UndefTok) {
 
   // If the callbacks want to know, tell them about the macro #undef.
   if (Callbacks)
-    Callbacks->MacroUndefined(MacroNameTok.getIdentifierInfo(), MI);
+    Callbacks->MacroUndefined(MacroNameTok.getLocation(),
+                              MacroNameTok.getIdentifierInfo(), MI);
 
   // Free macro definition.
   ReleaseMacroInfo(MI);

lib/Lex/PreprocessingRecord.cpp

@@ -118,7 +118,8 @@ void PreprocessingRecord::MacroDefined(const IdentifierInfo *II,
   PreprocessedEntities.push_back(Def);
 }
 
-void PreprocessingRecord::MacroUndefined(const IdentifierInfo *II, 
+void PreprocessingRecord::MacroUndefined(SourceLocation Loc,
+                                         const IdentifierInfo *II,
                                          const MacroInfo *MI) {
   llvm::DenseMap<const MacroInfo *, MacroDefinition *>::iterator Pos
     = MacroDefinitions.find(MI);

test/Preprocessor/dump-macros-undef.c

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -E -dD %s | FileCheck %s
+// PR7818
+
+// CHECK: # 1 "{{.+}}.c"
+#define X 3
+// CHECK: #define X 3
+#undef X
+// CHECK: #undef X