[llvm-commits] [llvm] r95559 - in /llvm/trunk: include/llvm/MC/MCExpr.h lib/MC/MCExpr.cpp lib/MC/MCMachOStreamer.cpp

[Chris Lattner]

Author: lattner
Date: Mon Feb  8 13:41:07 2010
New Revision: 95559

URL: http://llvm.org/viewvc/llvm-project?rev=95559&view=rev
Log:
add scaffolding for target-specific MCExprs.

Modified:
    llvm/trunk/include/llvm/MC/MCExpr.h
    llvm/trunk/lib/MC/MCExpr.cpp
    llvm/trunk/lib/MC/MCMachOStreamer.cpp

Modified: llvm/trunk/include/llvm/MC/MCExpr.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCExpr.h?rev=95559&r1=95558&r2=95559&view=diff

==============================================================================
--- llvm/trunk/include/llvm/MC/MCExpr.h (original)
+++ llvm/trunk/include/llvm/MC/MCExpr.h Mon Feb  8 13:41:07 2010
@@ -29,7 +29,8 @@
     Binary,    ///< Binary expressions.
     Constant,  ///< Constant expressions.
     SymbolRef, ///< References to labels and assigned expressions.
-    Unary      ///< Unary expressions.
+    Unary,     ///< Unary expressions.
+    Target     ///< Target specific expression.
   };
 
 private:
@@ -326,6 +327,28 @@
   static bool classof(const MCBinaryExpr *) { return true; }
 };
 
+/// MCTargetExpr - This is an extension point for target-specific MCExpr
+/// subclasses to implement.
+///
+/// NOTE: All subclasses are required to have trivial destructors because
+/// MCExprs are bump pointer allocated and not destructed.
+class MCTargetExpr : public MCExpr {
+  virtual ~MCTargetExpr(); // Not accessible.
+protected:
+  MCTargetExpr() : MCExpr(Target) {}
+  
+public:
+  
+  virtual void PrintImpl(raw_ostream &OS) const = 0;
+  virtual bool EvaluateAsRelocatableImpl(MCValue &Res) const = 0;
+
+  
+  static bool classof(const MCExpr *E) {
+    return E->getKind() == MCExpr::Target;
+  }
+  static bool classof(const MCTargetExpr *) { return true; }
+};
+
 } // end namespace llvm
 
 #endif

Modified: llvm/trunk/lib/MC/MCExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCExpr.cpp?rev=95559&r1=95558&r2=95559&view=diff

==============================================================================
--- llvm/trunk/lib/MC/MCExpr.cpp (original)
+++ llvm/trunk/lib/MC/MCExpr.cpp Mon Feb  8 13:41:07 2010
@@ -17,6 +17,8 @@
 
 void MCExpr::print(raw_ostream &OS) const {
   switch (getKind()) {
+  case MCExpr::Target:
+    return cast<MCTargetExpr>(this)->PrintImpl(OS);
   case MCExpr::Constant:
     OS << cast<MCConstantExpr>(*this).getValue();
     return;
@@ -131,6 +133,7 @@
   return Create(Ctx.GetOrCreateSymbol(Name), Ctx);
 }
 
+MCTargetExpr::~MCTargetExpr() {}
 
 /* *** */
 
@@ -168,6 +171,9 @@
 
 bool MCExpr::EvaluateAsRelocatable(MCValue &Res) const {
   switch (getKind()) {
+  case Target:
+    return cast<MCTargetExpr>(this)->EvaluateAsRelocatableImpl(Res);
+      
   case Constant:
     Res = MCValue::get(cast<MCConstantExpr>(this)->getValue());
     return true;

Modified: llvm/trunk/lib/MC/MCMachOStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCMachOStreamer.cpp?rev=95559&r1=95558&r2=95559&view=diff

==============================================================================
--- llvm/trunk/lib/MC/MCMachOStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCMachOStreamer.cpp Mon Feb  8 13:41:07 2010
@@ -87,6 +87,7 @@
 
   const MCExpr *AddValueSymbols(const MCExpr *Value) {
     switch (Value->getKind()) {
+    case MCExpr::Target: assert(0 && "Can't handle target exprs yet!");
     case MCExpr::Constant:
       break;