1 files changed, 48 insertions, 0 deletions
diff --git a/include/cps/ExceptionHandler.h b/include/cps/ExceptionHandler.h
new file mode 100644
index 0000000..5c846ae
--- /dev/null
+++ b/include/cps/ExceptionHandler.h
@@ -0,0 +1,48 @@
+#pragma once
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Module.h"
+#include <map>
+#include <vector>
+
+namespace cps {
+
+// C++ ABI exception emission. State is keyed by function because file helper
+// bodies and user functions are emitted using the same builder as their caller.
+class ExceptionHandler {
+    struct Handler {
+        llvm::BasicBlock *Target;
+        llvm::AllocaInst *Exception;
+        unsigned CatchDepth;
+    };
+    struct FunctionState {
+        std::vector<Handler> Handlers;
+        unsigned CatchDepth = 0;
+    };
+
+    llvm::LLVMContext &Context;
+    llvm::IRBuilder<> &Builder;
+    llvm::Module &Module;
+    std::map<llvm::Function *, FunctionState> States;
+    llvm::FunctionCallee Allocate, Throw, BeginCatch, EndCatch, Personality;
+    llvm::GlobalVariable *IntTypeInfo = nullptr;
+
+    void ensureRuntime();
+    llvm::BasicBlock *emitUnwindDestination();
+
+public:
+    ExceptionHandler(llvm::LLVMContext &C, llvm::IRBuilder<> &B, llvm::Module &M)
+        : Context(C), Builder(B), Module(M) {}
+
+    void prepareFunction(llvm::Function *F);
+    void pushHandler(llvm::BasicBlock *Target);
+    llvm::AllocaInst *popHandler();
+    void beginCatch(llvm::AllocaInst *Exception);
+    void endCatch();
+    void emitReturnCleanup();
+
+    llvm::Value *emitCall(llvm::FunctionCallee Callee, llvm::ArrayRef<llvm::Value *> Args,
+                          const llvm::Twine &Name = "");
+    void emitThrow();
+};
+
+} // namespace cps