Implement preprocessor code completion where a macro name is expected,
e.g., after #ifdef/#ifndef or #undef, or inside a defined <macroname>
expression in a preprocessor conditional.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111954 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index e0729f1..8da7def 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -75,6 +75,13 @@
   // Read the token, don't allow macro expansion on it.
   LexUnexpandedToken(MacroNameTok);
 
+  if (MacroNameTok.is(tok::code_completion)) {
+    if (CodeComplete)
+      CodeComplete->CodeCompleteMacroName(isDefineUndef == 1);
+    LexUnexpandedToken(MacroNameTok);
+    return;
+  }
+  
   // Missing macro name?
   if (MacroNameTok.is(tok::eom)) {
     Diag(MacroNameTok, diag::err_pp_missing_macro_name);
diff --git a/lib/Lex/PPExpressions.cpp b/lib/Lex/PPExpressions.cpp
index 9920c4c..73f3d4e 100644
--- a/lib/Lex/PPExpressions.cpp
+++ b/lib/Lex/PPExpressions.cpp
@@ -19,6 +19,7 @@
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Lex/MacroInfo.h"
 #include "clang/Lex/LiteralSupport.h"
+#include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "llvm/ADT/APSInt.h"
@@ -92,6 +93,12 @@
     PP.LexUnexpandedToken(PeekTok);
   }
 
+  if (PeekTok.is(tok::code_completion)) {
+    if (PP.getCodeCompletionHandler())
+      PP.getCodeCompletionHandler()->CodeCompleteMacroName(false);
+    PP.LexUnexpandedToken(PeekTok);
+  }
+  
   // If we don't have a pp-identifier now, this is an error.
   if ((II = PeekTok.getIdentifierInfo()) == 0) {
     PP.Diag(PeekTok, diag::err_pp_defined_requires_identifier);
@@ -697,7 +704,7 @@
   // Peek ahead one token.
   Token Tok;
   Lex(Tok);
-
+  
   // C99 6.10.1p3 - All expressions are evaluated as intmax_t or uintmax_t.
   unsigned BitWidth = getTargetInfo().getIntMaxTWidth();