Update llvm/clang to trunk r126547.

There are several bugfixes in this update, but the most important one is
to ensure __start_ and __stop_ symbols for linker sets and kernel module
metadata are always emitted in object files:

  http://llvm.org/bugs/show_bug.cgi?id=9292

Before this fix, if you compiled kernel modules with clang, they would
not be properly processed by kldxref, and if they had any dependencies,
the kernel would fail to load those.  Another problem occurred when
attempting to mount a tmpfs filesystem, which would result in 'operation
not supported by device'.

3 files changed, 42 insertions, 40 deletions

diff --git a/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp b/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp
index 0f0d25b..3e871ae 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp
@@ -86,6 +86,7 @@ void Preprocessor::DiscardUntilEndOfDirective() {
   Token Tmp;
   do {
     LexUnexpandedToken(Tmp);
+    assert(Tmp.isNot(tok::eof) && "EOF seen while discarding directive tokens");
   } while (Tmp.isNot(tok::eom));
 }
 
@@ -167,10 +168,12 @@ void Preprocessor::CheckEndOfDirective(const char *DirType, bool EnableMacros) {
 
   if (Tmp.isNot(tok::eom)) {
     // Add a fixit in GNU/C99/C++ mode.  Don't offer a fixit for strict-C89,
-    // because it is more trouble than it is worth to insert /**/ and check that
-    // there is no /**/ in the range also.
+    // or if this is a macro-style preprocessing directive, because it is more
+    // trouble than it is worth to insert /**/ and check that there is no /**/
+    // in the range also.
     FixItHint Hint;
-    if (Features.GNUMode || Features.C99 || Features.CPlusPlus)
+    if ((Features.GNUMode || Features.C99 || Features.CPlusPlus) &&
+        !CurTokenLexer)
       Hint = FixItHint::CreateInsertion(Tmp.getLocation(),"//");
     Diag(Tmp, diag::ext_pp_extra_tokens_at_eol) << DirType << Hint;
     DiscardUntilEndOfDirective();
diff --git a/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp b/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp
index f0475bc..80d3bb1 100644
--- a/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp
@@ -110,7 +110,8 @@ void Preprocessor::HandlePragmaDirective(unsigned Introducer) {
   PragmaHandlers->HandlePragma(*this, PragmaIntroducerKind(Introducer), Tok);
 
   // If the pragma handler didn't read the rest of the line, consume it now.
-  if (CurPPLexer && CurPPLexer->ParsingPreprocessorDirective)
+  if ((CurTokenLexer && CurTokenLexer->isParsingPreprocessorDirective()) 
+   || (CurPPLexer && CurPPLexer->ParsingPreprocessorDirective))
     DiscardUntilEndOfDirective();
 }
 
@@ -174,7 +175,22 @@ void Preprocessor::Handle_Pragma(Token &Tok) {
     }
   }
   
-  Handle_Pragma(PIK__Pragma, StrVal, PragmaLoc, RParenLoc);
+  // Plop the string (including the newline and trailing null) into a buffer
+  // where we can lex it.
+  Token TmpTok;
+  TmpTok.startToken();
+  CreateString(&StrVal[0], StrVal.size(), TmpTok);
+  SourceLocation TokLoc = TmpTok.getLocation();
+
+  // Make and enter a lexer object so that we lex and expand the tokens just
+  // like any others.
+  Lexer *TL = Lexer::Create_PragmaLexer(TokLoc, PragmaLoc, RParenLoc,
+                                        StrVal.size(), *this);
+
+  EnterSourceFileWithLexer(TL, 0);
+
+  // With everything set up, lex this as a #pragma directive.
+  HandlePragmaDirective(PIK__Pragma);
 
   // Finally, return whatever came after the pragma directive.
   return Lex(Tok);
@@ -193,16 +209,16 @@ void Preprocessor::HandleMicrosoft__pragma(Token &Tok) {
     return;
   }
 
-  // Get the tokens enclosed within the __pragma().
+  // Get the tokens enclosed within the __pragma(), as well as the final ')'.
   llvm::SmallVector<Token, 32> PragmaToks;
   int NumParens = 0;
   Lex(Tok);
   while (Tok.isNot(tok::eof)) {
+    PragmaToks.push_back(Tok);
     if (Tok.is(tok::l_paren))
       NumParens++;
     else if (Tok.is(tok::r_paren) && NumParens-- == 0)
       break;
-    PragmaToks.push_back(Tok);
     Lex(Tok);
   }
 
@@ -211,45 +227,23 @@ void Preprocessor::HandleMicrosoft__pragma(Token &Tok) {
     return;
   }
 
-  // Build the pragma string.
-  std::string StrVal = " ";
-  for (llvm::SmallVector<Token, 32>::iterator I =
-       PragmaToks.begin(), E = PragmaToks.end(); I != E; ++I) {
-    StrVal += getSpelling(*I);
-  }
-  
-  SourceLocation RParenLoc = Tok.getLocation();
-
-  Handle_Pragma(PIK___pragma, StrVal, PragmaLoc, RParenLoc);
+  PragmaToks.front().setFlag(Token::LeadingSpace);
 
-  // Finally, return whatever came after the pragma directive.
-  return Lex(Tok);
-}
+  // Replace the ')' with an EOM to mark the end of the pragma.
+  PragmaToks.back().setKind(tok::eom);
 
-void Preprocessor::Handle_Pragma(unsigned Introducer,
-                                 const std::string &StrVal,
-                                 SourceLocation PragmaLoc,
-                                 SourceLocation RParenLoc) {
+  Token *TokArray = new Token[PragmaToks.size()];
+  std::copy(PragmaToks.begin(), PragmaToks.end(), TokArray);
 
-  // Plop the string (including the newline and trailing null) into a buffer
-  // where we can lex it.
-  Token TmpTok;
-  TmpTok.startToken();
-  CreateString(&StrVal[0], StrVal.size(), TmpTok);
-  SourceLocation TokLoc = TmpTok.getLocation();
-
-  // Make and enter a lexer object so that we lex and expand the tokens just
-  // like any others.
-  Lexer *TL = Lexer::Create_PragmaLexer(TokLoc, PragmaLoc, RParenLoc,
-                                        StrVal.size(), *this);
-
-  EnterSourceFileWithLexer(TL, 0);
+  // Push the tokens onto the stack.
+  EnterTokenStream(TokArray, PragmaToks.size(), true, true);
 
   // With everything set up, lex this as a #pragma directive.
-  HandlePragmaDirective(Introducer);
-}
-
+  HandlePragmaDirective(PIK___pragma);
 
+  // Finally, return whatever came after the pragma directive.
+  return Lex(Tok);
+}
 
 /// HandlePragmaOnce - Handle #pragma once.  OnceTok is the 'once'.
 ///
diff --git a/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp b/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp
index ea39b47..caa44bf 100644
--- a/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp
@@ -543,6 +543,11 @@ unsigned TokenLexer::isNextTokenLParen() const {
   return Tokens[CurToken].is(tok::l_paren);
 }
 
+/// isParsingPreprocessorDirective - Return true if we are in the middle of a
+/// preprocessor directive.
+bool TokenLexer::isParsingPreprocessorDirective() const {
+  return Tokens[NumTokens-1].is(tok::eom) && !isAtEnd();
+}
 
 /// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes
 /// together to form a comment that comments out everything in the current