Better framework for conditional cleanups; untested as yet.
I'm separately committing this because it incidentally changes some
block orderings and minor IR issues, like using a phi instead of
an unnecessary alloca.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124277 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGException.cpp b/lib/CodeGen/CGException.cpp
index 78655bd..5845f1e 100644
--- a/lib/CodeGen/CGException.cpp
+++ b/lib/CodeGen/CGException.cpp
@@ -172,6 +172,22 @@
BranchFixups.pop_back();
}
+llvm::Value *CodeGenFunction::initFullExprCleanup() {
+ // Create a variable to decide whether the cleanup needs to be run.
+ llvm::AllocaInst *run = CreateTempAlloca(Builder.getInt1Ty(), "cleanup.cond");
+
+ // Initialize it to false at a site that's guaranteed to be run
+ // before each evaluation.
+ llvm::BasicBlock *block = OutermostConditional->getStartingBlock();
+ new llvm::StoreInst(Builder.getFalse(), run,
+ block->getFirstNonPHIOrDbg());
+
+ // Initialize it to true at the current location.
+ Builder.CreateStore(Builder.getTrue(), run);
+
+ return run;
+}
+
static llvm::Constant *getAllocateExceptionFn(CodeGenFunction &CGF) {
// void *__cxa_allocate_exception(size_t thrown_size);
const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType());
@@ -1656,3 +1672,23 @@
EHScopeStack::Cleanup::~Cleanup() {
llvm_unreachable("Cleanup is indestructable");
}
+
+void EHScopeStack::ConditionalCleanup::Emit(CodeGenFunction &CGF,
+ bool IsForEHCleanup) {
+ // Determine whether we should run the cleanup.
+ llvm::Value *condVal = CGF.Builder.CreateLoad(cond, "cond.should-run");
+
+ llvm::BasicBlock *cleanup = CGF.createBasicBlock("cond-cleanup.run");
+ llvm::BasicBlock *cont = CGF.createBasicBlock("cond-cleanup.cont");
+
+ // If we shouldn't run the cleanup, jump directly to the continuation block.
+ CGF.Builder.CreateCondBr(condVal, cleanup, cont);
+ CGF.EmitBlock(cleanup);
+
+ // Emit the core of the cleanup.
+ EmitImpl(CGF, IsForEHCleanup);
+ assert(CGF.HaveInsertPoint() && "cleanup didn't end with valid IP!");
+
+ // Fall into the continuation block.
+ CGF.EmitBlock(cont);
+}