From 9dfed9fdb64e8b9e81aba9c749059287a044e134 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 7 Dec 2009 01:58:34 +0000
Subject: [PATCH] fix -dM with variadic macros, PR5699

llvm-svn: 90735
---
 .../lib/Frontend/PrintPreprocessedOutput.cpp  | 23 ++++++++++++-------
 clang/test/Preprocessor/dump_macros.c         |  9 ++++++++
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/clang/lib/Frontend/PrintPreprocessedOutput.cpp b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
index e0186abeb49c..c23c6e3b9a80 100644
--- a/clang/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -28,6 +28,13 @@
 #include <cstdio>
 using namespace clang;
 
+static void PrintArgName(const IdentifierInfo *II, llvm::raw_ostream &OS) {
+  if (II->getName() == "__VA_ARGS__")
+    OS << "...";
+  else
+    OS << II->getName();
+}
+
 /// PrintMacroDefinition - Print a macro definition in a form that will be
 /// properly accepted back as a definition.
 static void PrintMacroDefinition(const IdentifierInfo &II, const MacroInfo &MI,
@@ -39,19 +46,19 @@ static void PrintMacroDefinition(const IdentifierInfo &II, const MacroInfo &MI,
     if (MI.arg_empty())
       ;
     else if (MI.getNumArgs() == 1)
-      OS << (*MI.arg_begin())->getName();
+      PrintArgName(*MI.arg_begin(), OS);
     else {
       MacroInfo::arg_iterator AI = MI.arg_begin(), E = MI.arg_end();
       OS << (*AI++)->getName();
-      while (AI != E)
-        OS << ',' << (*AI++)->getName();
+      while (AI != E) {
+        OS << ',';
+        PrintArgName(*AI++, OS);
+      }
     }
 
-    if (MI.isVariadic()) {
-      if (!MI.arg_empty())
-        OS << ',';
-      OS << "...";
-    }
+    if (MI.isGNUVarargs())
+      OS << "...";  // #define foo(x...)
+    
     OS << ')';
   }
 
diff --git a/clang/test/Preprocessor/dump_macros.c b/clang/test/Preprocessor/dump_macros.c
index 29b1d293943e..b4d290612722 100644
--- a/clang/test/Preprocessor/dump_macros.c
+++ b/clang/test/Preprocessor/dump_macros.c
@@ -27,3 +27,12 @@
 #define G 1
 #undef G
 #define G 2
+
+// Variadic macros of various sorts. PR5699
+
+// CHECK: H(x,...) __VA_ARGS__
+#define H(x, ...) __VA_ARGS__
+// CHECK: I(...) __VA_ARGS__
+#define I(...) __VA_ARGS__
+// CHECK: J(x...) __VA_ARGS__
+#define J(x ...) __VA_ARGS__