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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130055 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 20 insertions, 1 deletions

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 436a2a42a4..f5dacfa6cf 100644
--- a/lib/Driver/Tools.cpp
+++ b/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))
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 0dd2093b7a..daaaad0c2c 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/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;
diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index ff3cf4b9cd..802d66ff0e 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/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)