Add support for unreachable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17056 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/PostDominators.cpp b/lib/Analysis/PostDominators.cpp
index 0882294..4f9d1d1 100644
--- a/lib/Analysis/PostDominators.cpp
+++ b/lib/Analysis/PostDominators.cpp
@@ -40,8 +40,7 @@
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
Doms[I]; // Initialize to empty
- if (isa<ReturnInst>(I->getTerminator()) ||
- isa<UnwindInst>(I->getTerminator()))
+ if (succ_begin(I) == succ_end(I))
Roots.push_back(I);
}
diff --git a/lib/ExecutionEngine/Interpreter/Execution.cpp b/lib/ExecutionEngine/Interpreter/Execution.cpp
index 589ac7f..8616656 100644
--- a/lib/ExecutionEngine/Interpreter/Execution.cpp
+++ b/lib/ExecutionEngine/Interpreter/Execution.cpp
@@ -616,6 +616,11 @@
SwitchToNewBasicBlock(cast<InvokeInst>(Inst)->getUnwindDest(), InvokingSF);
}
+void Interpreter::visitUnreachableInst(UnreachableInst &I) {
+ std::cerr << "ERROR: Program executed an 'unreachable' instruction!\n";
+ abort();
+}
+
void Interpreter::visitBranchInst(BranchInst &I) {
ExecutionContext &SF = ECStack.back();
BasicBlock *Dest;
diff --git a/lib/ExecutionEngine/Interpreter/Interpreter.h b/lib/ExecutionEngine/Interpreter/Interpreter.h
index d6e590d..e146135 100644
--- a/lib/ExecutionEngine/Interpreter/Interpreter.h
+++ b/lib/ExecutionEngine/Interpreter/Interpreter.h
@@ -145,6 +145,7 @@
void visitCallInst(CallInst &I) { visitCallSite (CallSite (&I)); }
void visitInvokeInst(InvokeInst &I) { visitCallSite (CallSite (&I)); }
void visitUnwindInst(UnwindInst &I);
+ void visitUnreachableInst(UnreachableInst &I);
void visitShl(ShiftInst &I);
void visitShr(ShiftInst &I);
diff --git a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
index 5c87a5b..9776163 100644
--- a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
+++ b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
@@ -46,13 +46,16 @@
//
std::vector<BasicBlock*> ReturningBlocks;
std::vector<BasicBlock*> UnwindingBlocks;
+ std::vector<BasicBlock*> UnreachableBlocks;
for(Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
if (isa<ReturnInst>(I->getTerminator()))
ReturningBlocks.push_back(I);
else if (isa<UnwindInst>(I->getTerminator()))
UnwindingBlocks.push_back(I);
+ else if (isa<UnreachableInst>(I->getTerminator()))
+ UnreachableBlocks.push_back(I);
- // Handle unwinding blocks first...
+ // Handle unwinding blocks first.
if (UnwindingBlocks.empty()) {
UnwindBlock = 0;
} else if (UnwindingBlocks.size() == 1) {
@@ -64,12 +67,29 @@
for (std::vector<BasicBlock*>::iterator I = UnwindingBlocks.begin(),
E = UnwindingBlocks.end(); I != E; ++I) {
BasicBlock *BB = *I;
- BB->getInstList().pop_back(); // Remove the return insn
+ BB->getInstList().pop_back(); // Remove the unwind insn
new BranchInst(UnwindBlock, BB);
}
}
- // Now handle return blocks...
+ // Then unreachable blocks.
+ if (UnreachableBlocks.empty()) {
+ UnreachableBlock = 0;
+ } else if (UnreachableBlocks.size() == 1) {
+ UnreachableBlock = UnreachableBlocks.front();
+ } else {
+ UnreachableBlock = new BasicBlock("UnifiedUnreachableBlock", &F);
+ new UnreachableInst(UnreachableBlock);
+
+ for (std::vector<BasicBlock*>::iterator I = UnreachableBlocks.begin(),
+ E = UnreachableBlocks.end(); I != E; ++I) {
+ BasicBlock *BB = *I;
+ BB->getInstList().pop_back(); // Remove the unreachable inst.
+ new BranchInst(UnreachableBlock, BB);
+ }
+ }
+
+ // Now handle return blocks.
if (ReturningBlocks.empty()) {
ReturnBlock = 0;
return false; // No blocks return