add interpreter support for indirect goto / blockaddress. The interpreter

now correctly runs clang's test/CodeGen/indirect-goto.c.  The JIT will abort
on it until someone feels compelled to implement this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85488 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ExecutionEngine/ExecutionEngine.h

@@ -268,6 +268,12 @@ public:
   ///
   virtual void *getPointerToFunction(Function *F) = 0;
 
+  /// getPointerToBasicBlock - The different EE's represent basic blocks in
+  /// different ways.  Return the representation for a blockaddress of the
+  /// specified block.
+  ///
+  virtual void *getPointerToBasicBlock(BasicBlock *BB) = 0;
+  
   /// getPointerToFunctionOrStub - If the specified function has been
   /// code-gen'd, return a pointer to the function.  If not, compile it, or use
   /// a stub to implement lazy compilation if available.  See

lib/ExecutionEngine/ExecutionEngine.cpp

@@ -760,8 +760,11 @@ GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
       Result.PointerVal = 0;
     else if (const Function *F = dyn_cast<Function>(C))
       Result = PTOGV(getPointerToFunctionOrStub(const_cast<Function*>(F)));
-    else if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
+    else if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
       Result = PTOGV(getOrEmitGlobalVariable(const_cast<GlobalVariable*>(GV)));
+    else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
+      Result = PTOGV(getPointerToBasicBlock(const_cast<BasicBlock*>(
+                                                        BA->getBasicBlock())));
     else
       llvm_unreachable("Unknown constant pointer type!");
     break;

lib/ExecutionEngine/Interpreter/Execution.cpp

@@ -572,9 +572,9 @@ void Interpreter::exitCalled(GenericValue GV) {
   // runAtExitHandlers() assumes there are no stack frames, but
   // if exit() was called, then it had a stack frame. Blow away
   // the stack before interpreting atexit handlers.
-  ECStack.clear ();
-  runAtExitHandlers ();
-  exit (GV.IntVal.zextOrTrunc(32).getZExtValue());
+  ECStack.clear();
+  runAtExitHandlers();
+  exit(GV.IntVal.zextOrTrunc(32).getZExtValue());
 }
 
 /// Pop the last stack frame off of ECStack and then copy the result
@@ -585,8 +585,8 @@ void Interpreter::exitCalled(GenericValue GV) {
 /// care of switching to the normal destination BB, if we are returning
 /// from an invoke.
 ///
-void Interpreter::popStackAndReturnValueToCaller (const Type *RetTy,
-                                                  GenericValue Result) {
+void Interpreter::popStackAndReturnValueToCaller(const Type *RetTy,
+                                                 GenericValue Result) {
   // Pop the current stack frame.
   ECStack.pop_back();
 
@@ -629,15 +629,15 @@ void Interpreter::visitUnwindInst(UnwindInst &I) {
   // Unwind stack
   Instruction *Inst;
   do {
-    ECStack.pop_back ();
-    if (ECStack.empty ())
+    ECStack.pop_back();
+    if (ECStack.empty())
       llvm_report_error("Empty stack during unwind!");
-    Inst = ECStack.back ().Caller.getInstruction ();
-  } while (!(Inst && isa<InvokeInst> (Inst)));
+    Inst = ECStack.back().Caller.getInstruction();
+  } while (!(Inst && isa<InvokeInst>(Inst)));
 
   // Return from invoke
-  ExecutionContext &InvokingSF = ECStack.back ();
-  InvokingSF.Caller = CallSite ();
+  ExecutionContext &InvokingSF = ECStack.back();
+  InvokingSF.Caller = CallSite();
 
   // Go to exceptional destination BB of invoke instruction
   SwitchToNewBasicBlock(cast<InvokeInst>(Inst)->getUnwindDest(), InvokingSF);
@@ -678,6 +678,13 @@ void Interpreter::visitSwitchInst(SwitchInst &I) {
   SwitchToNewBasicBlock(Dest, SF);
 }
 
+void Interpreter::visitIndirectBrInst(IndirectBrInst &I) {
+  ExecutionContext &SF = ECStack.back();
+  void *Dest = GVTOP(getOperandValue(I.getAddress(), SF));
+  SwitchToNewBasicBlock((BasicBlock*)Dest, SF);
+}
+
+
 // SwitchToNewBasicBlock - This method is used to jump to a new basic block.
 // This function handles the actual updating of block and instruction iterators
 // as well as execution of all of the PHI nodes in the destination block.
@@ -827,7 +834,7 @@ void Interpreter::visitCallSite(CallSite CS) {
 
   // Check to see if this is an intrinsic function call...
   Function *F = CS.getCalledFunction();
-  if (F && F->isDeclaration ())
+  if (F && F->isDeclaration())
     switch (F->getIntrinsicID()) {
     case Intrinsic::not_intrinsic:
       break;

lib/ExecutionEngine/Interpreter/Interpreter.h

@@ -135,6 +135,7 @@ public:
   void visitReturnInst(ReturnInst &I);
   void visitBranchInst(BranchInst &I);
   void visitSwitchInst(SwitchInst &I);
+  void visitIndirectBrInst(IndirectBrInst &I);
 
   void visitBinaryOperator(BinaryOperator &I);
   void visitICmpInst(ICmpInst &I);
@@ -202,6 +203,7 @@ private:  // Helper functions
   void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF);
 
   void *getPointerToFunction(Function *F) { return (void*)F; }
+  void *getPointerToBasicBlock(BasicBlock *BB) { return (void*)BB; }
 
   void initializeExecutionEngine() { }
   void initializeExternalFunctions();

lib/ExecutionEngine/JIT/JIT.h

@@ -128,6 +128,10 @@ public:
   ///
   void *getPointerToFunction(Function *F);
 
+  void *getPointerToBasicBlock(BasicBlock *BB) {
+    assert(0 && "JIT does not support address-of-label yet!");
+  }
+  
   /// getOrEmitGlobalVariable - Return the address of the specified global
   /// variable, possibly emitting it to memory if needed.  This is used by the
   /// Emitter.