Respect -Wnewline-eof even in C++11 mode.

If the user has requested this warning, we should emit it, even if it's not
an extension in the current language mode. However, being an extension is
more important, so prefer the pedantic warning or the pedantic-compatibility
warning if those are enabled.

<rdar://problem/12922063>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189110 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/DiagnosticGroups.td

@@ -190,6 +190,7 @@ def MismatchedReturnTypes : DiagGroup<"mismatched-return-types">;
 def MismatchedTags : DiagGroup<"mismatched-tags">;
 def MissingFieldInitializers : DiagGroup<"missing-field-initializers">;
 def ModuleConflict : DiagGroup<"module-conflict">;
+def NewlineEOF : DiagGroup<"newline-eof">;
 def NullArithmetic : DiagGroup<"null-arithmetic">;
 def NullCharacter : DiagGroup<"null-character">;
 def NullDereference : DiagGroup<"null-dereference">;

include/clang/Basic/DiagnosticLexKinds.td

@@ -47,7 +47,9 @@ def ext_line_comment : Extension<
   "// comments are not allowed in this language">,
   InGroup<Comment>;
 def ext_no_newline_eof : Extension<"no newline at end of file">, 
-  InGroup<DiagGroup<"newline-eof">>;
+  InGroup<NewlineEOF>;
+def warn_no_newline_eof : Warning<"no newline at end of file">,
+  InGroup<NewlineEOF>, DefaultIgnore;
 
 def warn_cxx98_compat_no_newline_eof : Warning<
   "C++98 requires newline at end of file">,

lib/Lex/Lexer.cpp

@@ -2410,10 +2410,28 @@ bool Lexer::LexEndOfFile(Token &Result, const char *CurPtr) {
 
   // C99 5.1.1.2p2: If the file is non-empty and didn't end in a newline, issue
   // a pedwarn.
-  if (CurPtr != BufferStart && (CurPtr[-1] != '\n' && CurPtr[-1] != '\r'))
-    Diag(BufferEnd, LangOpts.CPlusPlus11 ? // C++11 [lex.phases] 2.2 p2
-         diag::warn_cxx98_compat_no_newline_eof : diag::ext_no_newline_eof)
-    << FixItHint::CreateInsertion(getSourceLocation(BufferEnd), "\n");
+  if (CurPtr != BufferStart && (CurPtr[-1] != '\n' && CurPtr[-1] != '\r')) {
+    DiagnosticsEngine &Diags = PP->getDiagnostics();
+    SourceLocation EndLoc = getSourceLocation(BufferEnd);
+    unsigned DiagID;
+
+    if (LangOpts.CPlusPlus11) {
+      // C++11 [lex.phases] 2.2 p2
+      // Prefer the C++98 pedantic compatibility warning over the generic,
+      // non-extension, user-requested "missing newline at EOF" warning.
+      if (Diags.getDiagnosticLevel(diag::warn_cxx98_compat_no_newline_eof,
+                                   EndLoc) != DiagnosticsEngine::Ignored) {
+        DiagID = diag::warn_cxx98_compat_no_newline_eof;
+      } else {
+        DiagID = diag::warn_no_newline_eof;
+      }
+    } else {
+      DiagID = diag::ext_no_newline_eof;
+    }
+
+    Diag(BufferEnd, DiagID)
+      << FixItHint::CreateInsertion(EndLoc, "\n");
+  }
 
   BufferPtr = CurPtr;
 

test/Lexer/newline-eof-c++98-compat.cpp

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -fsyntax-only -Wc++98-compat-pedantic -std=c++11 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wc++98-compat-pedantic -Wnewline-eof -std=c++11 -verify %s
 
 // The following line isn't terminated, don't fix it.
 void foo() {} // expected-warning{{C++98 requires newline at end of file}}

test/Lexer/newline-eof.c

@@ -1,9 +1,15 @@
-// RUN: %clang_cc1 -fsyntax-only -Wnewline-eof -verify %s
-// RUN: %clang_cc1 -fsyntax-only -Wnewline-eof %s 2>&1 | FileCheck %s
+// RUN: %clang -fsyntax-only -Wnewline-eof -verify %s
+// RUN: %clang -fsyntax-only -pedantic -verify %s
+// RUN: %clang -fsyntax-only -x c++ -std=c++03 -pedantic -verify %s
+// RUN: %clang -fsyntax-only -Wnewline-eof %s 2>&1 | FileCheck %s
 // rdar://9133072
 
+// In C++11 mode, this is allowed, so don't warn in pedantic mode.
+// RUN: %clang -fsyntax-only -x c++ -std=c++11 -Wnewline-eof -verify %s
+// RUN: %clang -fsyntax-only -x c++ -std=c++11 -pedantic %s
+
 // Make sure the diagnostic shows up properly at the end of the last line.
-// CHECK: newline-eof.c:9:63
+// CHECK: newline-eof.c:[[@LINE+3]]:63
 
 // The following line isn't terminated, don't fix it.
 void foo() {} // expected-warning{{no newline at end of file}}