Add TargetInfo::useNeXTRuntimeAsDefault

- Used to autoselect runtime when neither -fnext-runtime nor
   -fgnu-runtime is specified.
 - Default impl is false, all darwin targets set it to true.

llvm-svn: 55231

clang/Driver/clang.cpp

@@ -387,7 +387,8 @@ NeXTRuntime("fnext-runtime",
 //   -trigraphs
 //   -fdollars-in-identifiers
 //   -fpascal-strings
-static void InitializeLanguageStandard(LangOptions &Options, LangKind LK) {
+static void InitializeLanguageStandard(LangOptions &Options, LangKind LK,
+                                       TargetInfo *Target) {
   if (LangStd == lang_unspecified) {
     // Based on the base language, pick one.
     switch (LK) {
@@ -454,8 +455,7 @@ static void InitializeLanguageStandard(LangOptions &Options, LangKind LK) {
   } else if (GNURuntime) {
     Options.NeXTRuntime = 0;
   } else {
-    // FIXME: Should autoselect based on platform.
-    Options.NeXTRuntime = 0;
+    Options.NeXTRuntime = Target->useNeXTRuntimeAsDefault();
   }
 }
 
@@ -1201,7 +1201,7 @@ int main(int argc, char **argv) {
       InitializeBaseLanguage();
       LangKind LK = GetLanguage(InFile);
       InitializeLangOptions(LangInfo, LK);
-      InitializeLanguageStandard(LangInfo, LK);
+      InitializeLanguageStandard(LangInfo, LK, Target.get());
       InitializeGCMode(LangInfo);
       
       // Process the -I options and set them in the HeaderInfo.

clang/include/clang/Basic/TargetInfo.h

@@ -206,8 +206,10 @@ public:
     const char * const Register;
   };
 
-  virtual bool useGlobalsForAutomaticVariables() const {return false;}
-  
+  virtual bool useGlobalsForAutomaticVariables() const { return false; }
+
+  virtual bool useNeXTRuntimeAsDefault() const { return false; }
+
 protected:
   virtual void getGCCRegNames(const char * const *&Names, 
                               unsigned &NumNames) const = 0;

clang/lib/Basic/Targets.cpp

@@ -501,6 +501,8 @@ public:
     PPC32TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace.
 
@@ -512,6 +514,8 @@ public:
     PPC64TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace.
 
@@ -656,6 +660,7 @@ public:
     X86_32TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace
 
@@ -735,6 +740,8 @@ public:
     X86_64TargetInfo::getTargetDefines(Defines);
     getDarwinDefines(Defines);
   }
+
+  virtual bool useNeXTRuntimeAsDefault() const { return true; }
 };
 } // end anonymous namespace.