4 files changed, 23 insertions, 10 deletions
diff --git a/llvm/lib/TableGen/Main.cpp b/llvm/lib/TableGen/Main.cpp
index d0ca756016f..e1cd6237832 100644
--- a/llvm/lib/TableGen/Main.cpp
+++ b/llvm/lib/TableGen/Main.cpp
@@ -64,11 +64,11 @@ static int createDependencyFile(const TGParser &Parser, const char *argv0) {
     return 1;
   }
   DepOut.os() << OutputFilename << ":";
-  const std::vector<std::string> &Dependencies = Parser.getDependencies();
-  for (std::vector<std::string>::const_iterator I = Dependencies.begin(),
-                                                E = Dependencies.end();
+  const TGLexer::DependenciesMapTy &Dependencies = Parser.getDependencies();
+  for (TGLexer::DependenciesMapTy::const_iterator I = Dependencies.begin(),
+                                                  E = Dependencies.end();
        I != E; ++I) {
-    DepOut.os() << " " << (*I);
+    DepOut.os() << " " << I->first;
   }
   DepOut.os() << "\n";
   DepOut.keep();
diff --git a/llvm/lib/TableGen/TGLexer.cpp b/llvm/lib/TableGen/TGLexer.cpp
index e75abcfa38b..c6be4f8a118 100644
--- a/llvm/lib/TableGen/TGLexer.cpp
+++ b/llvm/lib/TableGen/TGLexer.cpp
@@ -309,7 +309,15 @@ bool TGLexer::LexInclude() {
     return true;
   }
   
-  Dependencies.push_back(IncludedFile);
+  DependenciesMapTy::const_iterator Found = Dependencies.find(IncludedFile);
+  if (Found != Dependencies.end()) {
+    PrintError(getLoc(),
+               "File '" + IncludedFile + "' has already been included.");
+    SrcMgr.PrintMessage(Found->second, SourceMgr::DK_Note,
+                        "previously included here");
+    return true;
+  }
+  Dependencies.insert(std::make_pair(IncludedFile, getLoc()));
   // Save the line number and lex buffer of the includer.
   CurBuf = SrcMgr.getMemoryBuffer(CurBuffer);
   CurPtr = CurBuf->getBufferStart();
diff --git a/llvm/lib/TableGen/TGLexer.h b/llvm/lib/TableGen/TGLexer.h
index a0818f9db74..d1bd70d2eca 100644
--- a/llvm/lib/TableGen/TGLexer.h
+++ b/llvm/lib/TableGen/TGLexer.h
@@ -15,9 +15,10 @@
 #define TGLEXER_H
 
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/SMLoc.h"
 #include <cassert>
+#include <map>
 #include <string>
-#include <vector>
 
 namespace llvm {
 class MemoryBuffer;
@@ -73,9 +74,13 @@ class TGLexer {
   /// CurBuffer - This is the current buffer index we're lexing from as managed
   /// by the SourceMgr object.
   int CurBuffer;
+
+public:
+  typedef std::map<std::string, SMLoc> DependenciesMapTy;
+private:
   /// Dependencies - This is the list of all included files.
-  std::vector<std::string> Dependencies;
-  
+  DependenciesMapTy Dependencies;
+
 public:
   TGLexer(SourceMgr &SrcMgr);
   ~TGLexer() {}
@@ -84,7 +89,7 @@ public:
     return CurCode = LexToken();
   }
 
-  const std::vector<std::string> &getDependencies() const {
+  const DependenciesMapTy &getDependencies() const {
     return Dependencies;
   }
   
diff --git a/llvm/lib/TableGen/TGParser.h b/llvm/lib/TableGen/TGParser.h
index e55805d5525..044e3a02ba4 100644
--- a/llvm/lib/TableGen/TGParser.h
+++ b/llvm/lib/TableGen/TGParser.h
@@ -96,7 +96,7 @@ public:
   bool TokError(const Twine &Msg) const {
     return Error(Lex.getLoc(), Msg);
   }
-  const std::vector<std::string> &getDependencies() const {
+  const TGLexer::DependenciesMapTy &getDependencies() const {
     return Lex.getDependencies();
   }