OrdinaryMagician/vkdoom_m
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redid the exception mechanism for script-side access violations to be of more use for diagnosing problems.

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The original implementation just printed a mostly information-free message and then went on as if nothing has happened, making it ridiculously easy to write broken code and release it. Changed it to:

* Any VMAbortException will now terminate the game session and go back to the console.
* It will also print a VM stack trace with all open functions, including source file and line numbers pointing to the problem spots. For this the relevant information had to be added to the VMScriptFunction class.

An interesting effect here was that just throwing the exception object increased the VM's Exec function's stack size from 900 bytes to 70kb, because the compiler allocates a separate local buffer for every single instance of the exception object.
The obvious solution was to put this part into a subfunction so that it won't pollute the Exec function's own stack frame. Interesting side effect of this: Exec's stack requirement went down from 900 bytes to 600 bytes. This is still on the high side but already a lot better.
This commit is contained in:
Christoph Oelckers 2016-12-03 12:23:13 +01:00
commit b3783a3850
9 changed files with 231 additions and 114 deletions
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31
src/info.cpp
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@ -89,16 +89,35 @@ bool FState::CallAction(AActor *self, AActor *stateowner, FStateParamInfo *info,
stateret = NULL;
}
}
if (stateret == NULL)
try
{
GlobalVMStack.Call(ActionFunc, params, ActionFunc->ImplicitArgs, NULL, 0, NULL);
if (stateret == NULL)
{
GlobalVMStack.Call(ActionFunc, params, ActionFunc->ImplicitArgs, NULL, 0, NULL);
}
else
{
VMReturn ret;
ret.PointerAt((void **)stateret);
GlobalVMStack.Call(ActionFunc, params, ActionFunc->ImplicitArgs, &ret, 1, NULL);
}
}
else
catch (CVMAbortException &err)
{
VMReturn ret;
ret.PointerAt((void **)stateret);
GlobalVMStack.Call(ActionFunc, params, ActionFunc->ImplicitArgs, &ret, 1, NULL);
err.MaybePrintMessage();
auto owner = FState::StaticFindStateOwner(this);
int offs = int(this - owner->OwnedStates);
const char *callinfo = "";
if (info != nullptr && info->mStateType == STATE_Psprite)
{
if (stateowner->IsKindOf(RUNTIME_CLASS(AWeapon)) && stateowner != self) callinfo = "weapon ";
else callinfo = "overlay ";
}
err.stacktrace.AppendFormat("Called from %sstate %s.%d in %s\n", callinfo, owner->TypeName.GetChars(), offs, stateowner->GetClass()->TypeName.GetChars());
throw;
throw;
}
ActionCycles.Unclock();
return true;
}