[Issue Report]: nxdk does not implement strtod()

[StephenCWills]

Operating System

Other (please specify)

DevilutionX version

Custom build (please specify commit ID)

Describe

Platform: OG Xbox
Commit ID: 55a5337 (no release versions are affected)

The build for OG Xbox fails at startup with the following message.

Assertion failed: '0' in function 'strtod', file '/opt/nxdk/lib/xboxrt/libc_extensions/stdlib_ext_.c', line 91

To Reproduce

1. Run the OG Xbox build in xemu
2. You will see the error message almost immediately

Expected Behavior

No response

Additional context

I added some trace logging and found that the assertion is raised here in LuaInitialize().

devilutionX/Source/lua/lua.cpp

Lines 218 to 229 in 55a5337

	CurrentLuaState->commonPackages = lua.create_table_with(
	#ifdef _DEBUG
	"devilutionx.dev", LuaDevModule(lua),
	#endif
	"devilutionx.version", PROJECT_VERSION,
	"devilutionx.log", LuaLogModule(lua),
	"devilutionx.audio", LuaAudioModule(lua),
	"devilutionx.render", LuaRenderModule(lua),
	"devilutionx.message", [](std::string_view text) { EventPlrMsg(text, UiFlags::ColorRed); },
	// These packages are loaded without a sandbox:
	"devilutionx.events", CurrentLuaState->events,
	"inspect", RunScript(/*env=*/std::nullopt, "inspect", /*optional=*/false));

I didn't dig any deeper than this since I'm pretty sure it's called by Lua internals. There's likely no reasonable way for us to work around the missing function.

---

Someone already posted an issue for this a few years back: XboxDev/nxdk#508. We will probably need to submit a PR to have any hope of getting this implemented for 1.6.0. Otherwise, we'll just have to disable Lua on OG Xbox.

Here is the link to their stub for the function.
https://github.com/XboxDev/nxdk/blob/ed21e83da43b8b8da14a9a78cf2528d9b5df86a7/lib/xboxrt/libc_extensions/stdlib_ext_.c#L89-L93

---

Also, this isn't really necessary, but I did take a screenshot of the error earlier so I may as well share it.

[glebm]

nxdk uses PDClib, which doesn't have strtod but they have a draft implementation:

https://github.com/DevSolar/pdclib/blob/7d471427fa986a9f4cafb069af17821ee7868141/functions/_PDCLIB/_PDCLIB_strtod_main.c#L16-L20

It'd probably be best to submit a PR to PDClib directly.

[AJenbo]

XboxDev/nxdk-pdclib#57 (comment)

[glebm]

I found high quality public domain implementations of float<->string conversions in sqlite DevSolar/pdclib#5 (comment)

[glebm]

Sent a PR to PDClib with a partial strtod implementation based on the one from SQLite DevSolar/pdclib#22