Fix Clang's __DEPRECATED define to be controled by -Wdeprecated. This

matches GCC behavior which libstdc++ uses to limit #warning-based
messages about deprecation.

The machinery involves threading this through a new '-fdeprecated-macro'
flag for CC1. The flag defaults to "on", similarly to -Wdeprecated. We
turn the flag off in the driver when the warning is turned off (modulo
matching some GCC bugs). We record this as a language option, and key
the preprocessor on the option when introducing the define.

A separate flag rather than a '-D' flag allows us to properly represent
the difference between C and C++ builds (only C++ receives the define),
and it allows the specific behavior of following -Wdeprecated without
potentially impacting the set of user-provided macro flags.

llvm-svn: 130055

clang/include/clang/Basic/LangOptions.h

@@ -89,6 +89,8 @@ public:
                                   // used (instead of C99 semantics).
   unsigned NoInline          : 1; // Should __NO_INLINE__ be defined.
 
+  unsigned Deprecated        : 1; // Should __DEPRECATED be defined.
+
   unsigned ObjCGCBitmapPrint : 1; // Enable printing of gc's bitmap layout
                                   // for __weak/__strong ivars.
 
@@ -213,6 +215,8 @@ public:
     GNUInline = 0;
     NoInline = 0;
 
+    Deprecated = 1;  // -Wdeprecated defaults to "on".
+
     CharIsSigned = 1;
     ShortWChar = 0;
     ShortEnums = 0;

clang/include/clang/Driver/CC1Options.td

@@ -539,6 +539,10 @@ def fdelayed_template_parsing : Flag<"-fdelayed-template-parsing">,
            "translation unit ">;
 def funknown_anytype : Flag<"-funknown-anytype">,
   HelpText<"Enable parser support for the __unknown_anytype type; for testing purposes only">;
+def fdeprecated_macro : Flag<"-fdeprecated-macro">,
+  HelpText<"Defines the __DEPRECATED macro in C++ compilations">;
+def fno_deprecated_macro : Flag<"-fno-deprecated-macro">,
+  HelpText<"Undefines the __DEPRECATED macro in C++ compilations">;
 
 //===----------------------------------------------------------------------===//
 // Header Search Options

clang/include/clang/Driver/Options.td

@@ -166,6 +166,8 @@ def Wa_COMMA : CommaJoined<"-Wa,">,
   HelpText<"Pass the comma separated arguments in <arg> to the assembler">,
   MetaVarName<"<arg>">;
 def Wall : Flag<"-Wall">, Group<W_Group>;
+def Wdeprecated : Flag<"-Wdeprecated">, Group<W_Group>;
+def Wno_deprecated : Flag<"-Wno-deprecated">, Group<W_Group>;
 def Wextra : Flag<"-Wextra">, Group<W_Group>;
 def Wl_COMMA : CommaJoined<"-Wl,">, Flags<[LinkerInput, RenderAsInput]>,
   HelpText<"Pass the comma separated arguments in <arg> to the linker">,

clang/lib/Driver/Tools.cpp

@@ -1362,6 +1362,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-fconst-strings");
   }
 
+  // GCC provides a macro definition '__DEPRECATED' when -Wdeprecated is active
+  // during C++ compilation. CC1 uses '-fdeprecated-macro' to control this.
+  // Both '-Wdeprecated' and '-fdeprecated-macro' default to on, so the flag
+  // logic here is inverted.
+  if (Args.hasFlag(options::OPT_Wno_deprecated, options::OPT_Wdeprecated,
+                   false)) {
+    // GCC keeps this define even in the presence of '-w', match this behavior
+    // bug-for-bug.
+    CmdArgs.push_back("-fno-deprecated-macro");
+  }
+
   // Translate GCC's misnamer '-fasm' arguments to '-fgnu-keywords'.
   if (Arg *Asm = Args.getLastArg(options::OPT_fasm, options::OPT_fno_asm)) {
     if (Asm->getOption().matches(options::OPT_fasm))

clang/lib/Frontend/CompilerInvocation.cpp

@@ -694,6 +694,8 @@ static void LangOptsToArgs(const LangOptions &Opts,
     Res.push_back("-funknown-anytype");
   if (Opts.DelayedTemplateParsing)
     Res.push_back("-fdelayed-template-parsing");
+  if (!Opts.Deprecated)
+    Res.push_back("-fno-deprecated-macro");
 }
 
 static void PreprocessorOptsToArgs(const PreprocessorOptions &Opts,
@@ -1528,6 +1530,11 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.FakeAddressSpaceMap = Args.hasArg(OPT_ffake_address_space_map);
   Opts.ParseUnknownAnytype = Args.hasArg(OPT_funknown_anytype);
 
+  // Record whether the __DEPRECATED define was requested.
+  Opts.Deprecated = Args.hasFlag(OPT_fdeprecated_macro,
+                                 OPT_fno_deprecated_macro,
+                                 Opts.Deprecated);
+
   // FIXME: Eliminate this dependency.
   unsigned Opt = getOptimizationLevel(Args, IK, Diags);
   Opts.Optimize = Opt != 0;

clang/lib/Frontend/InitPreprocessor.cpp

@@ -319,7 +319,8 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
     Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
 
   if (LangOpts.CPlusPlus) {
-    Builder.defineMacro("__DEPRECATED");
+    if (LangOpts.Deprecated)
+      Builder.defineMacro("__DEPRECATED");
     Builder.defineMacro("__GNUG__", "4");
     Builder.defineMacro("__GXX_WEAK__");
     if (LangOpts.GNUMode)

clang/test/Driver/clang_f_opts.c

@@ -19,3 +19,11 @@
 // WRITE-STRINGS2-NOT: -fconst-strings
 // RUN: %clang -### -S -Wwrite-strings -w %s 2>&1 | FileCheck -check-prefix=WRITE-STRINGS3 %s
 // WRITE-STRINGS3: -fconst-strings
+
+// RUN: %clang -### -c %s 2>&1 | FileCheck -check-prefix=DEPRECATED-ON-CHECK %s
+// RUN: %clang -### -c -Wdeprecated %s 2>&1 | FileCheck -check-prefix=DEPRECATED-ON-CHECK %s
+// RUN: %clang -### -c -Wno-deprecated %s 2>&1 | FileCheck -check-prefix=DEPRECATED-OFF-CHECK %s
+// RUN: %clang -### -c -Wno-deprecated -Wdeprecated %s 2>&1 | FileCheck -check-prefix=DEPRECATED-ON-CHECK %s
+// RUN: %clang -### -c -w %s 2>&1 | FileCheck -check-prefix=DEPRECATED-ON-CHECK %s
+// DEPRECATED-OFF-CHECK: -fno-deprecated-macro
+// DEPRECATED-ON-CHECK-NOT: -fno-deprecated-macro