SafetyHook's InlineHook::call() invokes the trampoline through a __cdecl
pointer (the compiler default on x86). The functions we hook are __stdcall
(IDXGISwapChain::Present/Present1, the WASAPI render interfaces, and the
WINAPI SwapBuffers/wglSwapBuffers), so on 32-bit both sides cleaned the
stack -> ESP imbalance -> Run-Time Check Failure #0 and an instant crash.
On x64 every convention collapses to one, so it only bit 32-bit games:
Slaps and Beans (Unity/Rewired, 32-bit D3D11) froze the moment the Present
hook ran. The user's "crashes as soon as a button is pressed" was the
Present, not the button.
Switch every __stdcall trampoline call to SafetyHook's stdcall() (a no-op
on x64). The XInput/focus hooks were unaffected because they never call
the trampoline -- they return synthesized data.
Reproduction + regression coverage:
- tools/input_probe (coop_input_probe): injects, reports a connected pad,
toggles a button, and takes a disable_mask to bisect which subsystem
affects a game. Isolated the freeze to the video subsystem live.
- hook_selftest_x86 + present_hook_test_x86: the x86 sub-build now builds
and runs these (the x64 present_hook_test can't see a one-convention
bug). present_hook_test_x86 drives a real swapchain through the
trampoline -- it would hit RTC #0 before this fix.
- hook_selftest strengthened to exercise every loaded xinput DLL's full
export set (GetState, ordinal-100 GetStateEx, GetCapabilities, rumble
SetState) and to dump the SharedBlock layout.
- protocol.hpp: static_asserts lock the cross-bitness front-of-block
offsets (verified byte-identical on x86 and x64).
README roadmap trimmed (this milestone done) and a lessons-learned note
added on the call()/stdcall() convention trap.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
BlackMark
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