Don't use fprintf to emit this diagnostic!

llvm-svn: 246526

clang/include/clang/Basic/DiagnosticSerializationKinds.td

@@ -111,6 +111,10 @@ def note_module_odr_violation_different_definitions : Note<
 def err_module_odr_violation_different_instantiations : Error<
   "instantiation of %q0 is different in different modules">;
 
+def warn_module_uses_date_time : Warning<
+  "%select{precompiled header|module}0 uses __DATE__ or __TIME__">,
+  InGroup<DiagGroup<"pch-date-time">>;
+
 } // let CategoryName
 } // let Component
 

clang/lib/Serialization/ASTWriter.cpp

@@ -43,6 +43,7 @@
 #include "clang/Sema/IdentifierResolver.h"
 #include "clang/Sema/Sema.h"
 #include "clang/Serialization/ASTReader.h"
+#include "clang/Serialization/SerializationDiagnostic.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/Hashing.h"
@@ -2054,10 +2055,9 @@ void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
 
   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
-  // FIXME: use diagnostics subsystem for localization etc.
+  // FIXME: Include a location for the use, and say which one was used.
   if (PP.SawDateOrTime())
-    fprintf(stderr, "warning: precompiled header used __DATE__ or __TIME__.\n");
-
+    PP.Diag(SourceLocation(), diag::warn_module_uses_date_time) << IsModule;
 
   // Loop over all the macro directives that are live at the end of the file,
   // emitting each to the PP section.

clang/test/PCH/datetime.c

@@ -0,0 +1,3 @@
+// RUN: %clang_cc1 -x c-header %s -emit-pch -o %t 2>&1 | FileCheck %s
+// CHECK: precompiled header uses __DATE__ or __TIME__
+const char *p = __DATE__;