Revert "Revert "PPCallbacks::MacroUndefined, change signature and add test.""

This reverts commit r301469. It isn't needed with r301470, which fixes
the API break introduced in the original commit.

llvm-svn: 301472

2 files changed, 17 insertions, 15 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 8a56ddf2369..fd4e6d30def 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -2592,25 +2592,26 @@ void Preprocessor::HandleUndefDirective() {
   // Okay, we have a valid identifier to undef.
   auto *II = MacroNameTok.getIdentifierInfo();
   auto MD = getMacroDefinition(II);
+  UndefMacroDirective *Undef = nullptr;
+  
+  // If the macro is not defined, this is a noop undef.
+  if (const MacroInfo *MI = MD.getMacroInfo()) {
+    if (!MI->isUsed() && MI->isWarnIfUnused())
+      Diag(MI->getDefinitionLoc(), diag::pp_macro_not_used);
+
+    if (MI->isWarnIfUnused())
+      WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());
+
+    Undef = AllocateUndefMacroDirective(MacroNameTok.getLocation());
+  }
 
   // If the callbacks want to know, tell them about the macro #undef.
   // Note: no matter if the macro was defined or not.
   if (Callbacks)
-    Callbacks->MacroUndefined(MacroNameTok, MD);
-
-  // If the macro is not defined, this is a noop undef, just return.
-  const MacroInfo *MI = MD.getMacroInfo();
-  if (!MI)
-    return;
-
-  if (!MI->isUsed() && MI->isWarnIfUnused())
-    Diag(MI->getDefinitionLoc(), diag::pp_macro_not_used);
-
-  if (MI->isWarnIfUnused())
-    WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());
+    Callbacks->MacroUndefined(MacroNameTok, MD, Undef);
 
-  appendMacroDirective(MacroNameTok.getIdentifierInfo(),
-                       AllocateUndefMacroDirective(MacroNameTok.getLocation()));
+  if (Undef)
+    appendMacroDirective(II, Undef);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Lex/PreprocessingRecord.cpp b/clang/lib/Lex/PreprocessingRecord.cpp
index 13e15f3c943..03c4cbe589d 100644
--- a/clang/lib/Lex/PreprocessingRecord.cpp
+++ b/clang/lib/Lex/PreprocessingRecord.cpp
@@ -422,7 +422,8 @@ void PreprocessingRecord::MacroDefined(const Token &Id,
 }
 
 void PreprocessingRecord::MacroUndefined(const Token &Id,
-                                         const MacroDefinition &MD) {
+                                         const MacroDefinition &MD,
+                                         const MacroDirective *Undef) {
   MD.forAllDefinitions([&](MacroInfo *MI) { MacroDefinitions.erase(MI); });
 }