For some LLVM-as-library uses it is convenient to create a

subclass of TargetMachine which "forwards" all operations to an
existing internal TargetMachine member variable. In the usage context the
specific-machine class derived from TargetMachine is not visible,
only a reference to the generic base class TargetMachine. Although
getSubtargetImpl() is public in specific-machine classes derived from
TargetMachine, the TargetMachine class unfortunately has
getSubtargetImpl() protected (and accessing non-const members makes
abusing getSubtarget() unsuitable). Making it public in the base class
allows this forwarding pattern.

llvm-svn: 171976

Author: David Tweed

llvm/include/llvm/Target/TargetMachine.h

@@ -59,10 +59,6 @@ class TargetMachine {
   TargetMachine(const Target &T, StringRef TargetTriple,
                 StringRef CPU, StringRef FS, const TargetOptions &Options);
 
-  /// getSubtargetImpl - virtual method implemented by subclasses that returns
-  /// a reference to that target's TargetSubtargetInfo-derived member variable.
-  virtual const TargetSubtargetInfo *getSubtargetImpl() const { return 0; }
-
   /// TheTarget - The Target that this machine was created for.
   const Target &TheTarget;
 
@@ -95,6 +91,10 @@ class TargetMachine {
   const StringRef getTargetCPU() const { return TargetCPU; }
   const StringRef getTargetFeatureString() const { return TargetFS; }
 
+  /// getSubtargetImpl - virtual method implemented by subclasses that returns
+  /// a reference to that target's TargetSubtargetInfo-derived member variable.
+  virtual const TargetSubtargetInfo *getSubtargetImpl() const { return 0; }
+
   TargetOptions Options;
 
   // Interfaces to the major aspects of target machine information: