From 6424190cbf419ca14c5eccee3b02cdee16dd8d8d Mon Sep 17 00:00:00 2001
From: Jonathan Russell <russj159@yahoo.co.uk>
Date: Sat, 18 Aug 2018 18:03:18 +0100
Subject: [PATCH] - add first draft of abort exceptions

---
 src/scripting/vm/jit.cpp    | 59 +++++++++++++++++++++++++++++++++++++
 src/scripting/vm/vmexec.h   | 14 +++++++--
 src/scripting/vm/vmintern.h |  1 +
 3 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/src/scripting/vm/jit.cpp b/src/scripting/vm/jit.cpp
index 0e6badac8..ffba12cd4 100644
--- a/src/scripting/vm/jit.cpp
+++ b/src/scripting/vm/jit.cpp
@@ -292,6 +292,57 @@ static int64_t ToMemAddress(const void *d)
 	return (int64_t)(ptrdiff_t)d;
 }
 
+void setPCOnAbort(VMScriptFunction *sfunc, VMOP* pc) {
+	sfunc->pcOnJitAbort = pc;
+}
+
+template <typename T>
+void setCallArg(T call, int num, int64_t arg) {
+	call->setArg(num, asmjit::imm(arg));
+}
+
+void setCallArg(asmjit::CCFuncCall* call, int num, uint64_t arg) {
+	call->setArg(num, asmjit::imm_u(arg));
+}
+
+void setCallArg(asmjit::CCFuncCall* call, int num, const asmjit::Reg& arg) {
+	call->setArg(num, arg);
+}
+
+template <typename Arg>
+void setCallArg(asmjit::CCFuncCall* call, int num, Arg* arg) {
+	call->setArg(num, asmjit::imm_ptr(arg));
+}
+
+template <typename Arg>
+void emitCallVariadicArgs(asmjit::CCFuncCall* call, int num, Arg arg) {
+	setCallArg(call, num, arg);
+}
+
+template <typename Arg, typename... Args>
+void emitCallVariadicArgs(asmjit::CCFuncCall* call, int num, Arg arg, Args... args) {
+	setCallArg(call, num, arg);
+	emitCallVariadicArgs(call, num + 1, args...);
+}
+
+void emitCallVariadicArgs(asmjit::CCFuncCall*, int num) {}
+
+template <typename... ArgTypes, typename... Args>
+void emitAbortExceptionCall(asmjit::X86Compiler& cc, VMScriptFunction* sfunc, const VMOP* pc, EVMAbortException reason, const char* moreinfo, Args... args) {
+	using namespace asmjit;
+
+	auto ptr = cc.newIntPtr();
+
+	CCFuncCall* setPCCall = cc.call(imm_ptr((void*)setPCOnAbort), FuncSignature2<void, VMScriptFunction*, VMOP*>(CallConv::kIdHost));
+	setPCCall->setArg(0, imm_ptr(sfunc));
+	setPCCall->setArg(1, imm_ptr(pc));
+
+	CCFuncCall* throwAbortCall = cc.call(imm_ptr((void*)ThrowAbortException), FuncSignatureT<void, int, const char*, ArgTypes...>(CallConv::kIdHost));
+	throwAbortCall->setArg(0, imm(reason));
+	throwAbortCall->setArg(1, imm_ptr(moreinfo));
+	emitCallVariadicArgs(throwAbortCall, 2, args...);
+}
+
 static void CallSqrt(asmjit::X86Compiler& cc, const asmjit::X86Xmm &a, const asmjit::X86Xmm &b)
 {
 	using namespace asmjit;
@@ -902,10 +953,18 @@ JitFuncPtr JitCompile(VMScriptFunction *sfunc)
 			{
 				auto tmp0 = cc.newInt32();
 				auto tmp1 = cc.newInt32();
+				auto label = cc.newLabel();
+
+				cc.test(regD[C], regD[C]);
+				cc.je(label);
+
 				cc.mov(tmp0, regD[B]);
 				cc.cdq(tmp1, tmp0);
 				cc.idiv(tmp1, tmp0, regD[C]);
 				cc.mov(regD[A], tmp0);
+
+				cc.bind(label);
+				emitAbortExceptionCall(cc, sfunc, pc, X_DIVISION_BY_ZERO, nullptr);
 				break;
 			}
 			case OP_DIV_RK:
diff --git a/src/scripting/vm/vmexec.h b/src/scripting/vm/vmexec.h
index 8df0fb70b..52a9cc117 100644
--- a/src/scripting/vm/vmexec.h
+++ b/src/scripting/vm/vmexec.h
@@ -80,8 +80,18 @@ static int Exec(VMFrameStack *stack, const VMOP *pc, VMReturn *ret, int numret)
 			sfunc->JitFunc = JitCompile(sfunc);
 			sfunc->JitCompiled = true;
 		}
-		if (sfunc->JitFunc)
-			return sfunc->JitFunc(stack, &reg, ret, numret);
+		if (sfunc->JitFunc) {
+			try {
+				return sfunc->JitFunc(stack, &reg, ret, numret);
+			}
+			catch (CVMAbortException &err)
+			{
+				err.MaybePrintMessage();
+				err.stacktrace.AppendFormat("Called from %s at %s, line %d\n", sfunc->PrintableName.GetChars(), sfunc->SourceFileName.GetChars(), sfunc->PCToLine(sfunc->pcOnJitAbort));
+				// PrintParameters(reg.param + f->NumParam - B, B);
+				throw;
+			}
+		}
 	}
 
 	void *ptr;
diff --git a/src/scripting/vm/vmintern.h b/src/scripting/vm/vmintern.h
index 379ad7c5f..5888772e1 100644
--- a/src/scripting/vm/vmintern.h
+++ b/src/scripting/vm/vmintern.h
@@ -471,6 +471,7 @@ public:
 
 	bool JitCompiled = false;
 	JitFuncPtr JitFunc = nullptr;
+	VMOP* pcOnJitAbort = nullptr;
 
 	void InitExtra(void *addr);
 	void DestroyExtra(void *addr);