Adds a JIT based exception handling example to the examples directory.

[oota-llvm.git] / lib / VMCore / BasicBlock.cpp

diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp
index 3065766362e4a1394091ee919ccbd6f32b0041c6..16437bc130454d333166f9e99ef03cc6a7d3e260 100644 (file)
--- a/lib/VMCore/BasicBlock.cpp
+++ b/lib/VMCore/BasicBlock.cpp
@@ -14,11 +14,11 @@
 #include "llvm/BasicBlock.h"
 #include "llvm/Constants.h"
 #include "llvm/Instructions.h"
+#include "llvm/LLVMContext.h"
 #include "llvm/Type.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/LeakDetector.h"
-#include "llvm/Support/Compiler.h"
 #include "SymbolTableListTraitsImpl.h"
 #include <algorithm>
 using namespace llvm;
@@ -29,14 +29,18 @@ ValueSymbolTable *BasicBlock::getValueSymbolTable() {
   return 0;
 }
 
+LLVMContext &BasicBlock::getContext() const {
+  return getType()->getContext();
+}
+
 // Explicit instantiation of SymbolTableListTraits since some of the methods
 // are not in the public header file...
-template class SymbolTableListTraits<Instruction, BasicBlock>;
+template class llvm::SymbolTableListTraits<Instruction, BasicBlock>;
 
 
-BasicBlock::BasicBlock(const std::string &Name, Function *NewParent,
+BasicBlock::BasicBlock(LLVMContext &C, const Twine &Name, Function *NewParent,
                        BasicBlock *InsertBefore)
-  : Value(Type::LabelTy, Value::BasicBlockVal), Parent(0) {
+  : Value(Type::getLabelTy(C), Value::BasicBlockVal), Parent(0) {
 
   // Make sure that we get added to a function
   LeakDetector::addGarbageObject(this);
@@ -54,6 +58,24 @@ BasicBlock::BasicBlock(const std::string &Name, Function *NewParent,
 
 
 BasicBlock::~BasicBlock() {
+  // If the address of the block is taken and it is being deleted (e.g. because
+  // it is dead), this means that there is either a dangling constant expr
+  // hanging off the block, or an undefined use of the block (source code
+  // expecting the address of a label to keep the block alive even though there
+  // is no indirect branch).  Handle these cases by zapping the BlockAddress
+  // nodes.  There are no other possible uses at this point.
+  if (hasAddressTaken()) {
+    assert(!use_empty() && "There should be at least one blockaddress!");
+    Constant *Replacement =
+      ConstantInt::get(llvm::Type::getInt32Ty(getContext()), 1);
+    while (!use_empty()) {
+      BlockAddress *BA = cast<BlockAddress>(use_back());
+      BA->replaceAllUsesWith(ConstantExpr::getIntToPtr(Replacement,
+                                                       BA->getType()));
+      BA->destroyConstant();
+    }
+  }
+  
   assert(getParent() == 0 && "BasicBlock still linked into the program!");
   dropAllReferences();
   InstList.clear();
@@ -235,14 +257,15 @@ void BasicBlock::removePredecessor(BasicBlock *Pred,
 /// cause a degenerate basic block to be formed, having a terminator inside of
 /// the basic block).
 ///
-BasicBlock *BasicBlock::splitBasicBlock(iterator I, const std::string &BBName) {
+BasicBlock *BasicBlock::splitBasicBlock(iterator I, const Twine &BBName) {
   assert(getTerminator() && "Can't use splitBasicBlock on degenerate BB!");
   assert(I != InstList.end() &&
          "Trying to get me to create degenerate basic block!");
 
-  BasicBlock *InsertBefore = next(Function::iterator(this))
+  BasicBlock *InsertBefore = llvm::next(Function::iterator(this))
                                .getNodePtrUnchecked();
-  BasicBlock *New = BasicBlock::Create(BBName, getParent(), InsertBefore);
+  BasicBlock *New = BasicBlock::Create(getContext(), BBName,
+                                       getParent(), InsertBefore);
 
   // Move all of the specified instructions from the original basic block into
   // the new basic block.
@@ -272,3 +295,4 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const std::string &BBName) {
   }
   return New;
 }
+