TCA emitEndCatchHelper(CodeBlock& cb, UniqueStubs& us) {
Asm a { cb };
alignJmpTarget(cb);
Label debuggerReturn;
Label resumeCppUnwind;
auto const start = a.frontier();
a. cmpq (0, rvmtl()[unwinderDebuggerReturnSPOff()]);
a. jne8 (debuggerReturn);
// Normal endCatch situation: call back to tc_unwind_resume, which returns
// the catch trace (or null) in rax and the new vmfp in rdx.
a. movq (rvmfp(), rarg(0));
a. call (TCA(tc_unwind_resume));
a. movq (rdx, rvmfp());
a. testq(rax, rax);
a. jz8 (resumeCppUnwind);
a. jmp (rax); // rdx is still live if we're going to code from llvm
asm_label(a, resumeCppUnwind);
static_assert(sizeof(tl_regState) == 1,
"The following store must match the size of tl_regState");
auto vptr = emitTLSAddr(a, tl_regState, rax);
Vasm::prefix(a, vptr).
storeb(static_cast<int32_t>(VMRegState::CLEAN), vptr.mr());
a. loadq(rvmtl()[unwinderExnOff()], rarg(0));
emitCall(a, TCA(_Unwind_Resume), arg_regs(1));
us.endCatchHelperPast = a.frontier();
a. ud2();
asm_label(a, debuggerReturn);
a. loadq (rvmtl()[unwinderDebuggerReturnSPOff()], rvmsp());
a. storeq(0, rvmtl()[unwinderDebuggerReturnSPOff()]);
svcreq::emit_persistent(a.code(), folly::none, REQ_POST_DEBUGGER_RET);
return start;
}
void emitTransCounterInc(Asm& a) {
emitTransCounterInc(Vauto(a.code()).main());
}
void emitCall(Asm& a, CppCall call, RegSet args) {
emitCall(Vauto(a.code()).main(), call, args);
}