Skip to content

Add proper stdcall name mangling to gas assembly on 32bit windows #1762

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
charles-lunarg merged 2 commits into from
Aug 18, 2025
Merged

Add proper stdcall name mangling to gas assembly on 32bit windows #1762

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
42a567e
Fix stdcall assembly symbol naming on win32
BtbN Aug 17, 2025
b3984f1
Silence stdcall fixup warnings on 32bit mingw builds
BtbN Aug 17, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions loader/CMakeLists.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -393,6 +393,10 @@ if(WIN32)
set_target_properties(vulkan
PROPERTIES
PREFIX "")
# let the linker just fix up the stdcall mangling, like on msvc
if(CMAKE_SIZEOF_VOID_P EQUAL 4)
target_link_options(vulkan PRIVATE "-Wl,--enable-stdcall-fixup")
endif()
endif()

if(MSVC AND ENABLE_WIN10_ONECORE)
Expand Down
19 changes: 19 additions & 0 deletions loader/unknown_ext_chain_gas_x86.S
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -88,11 +88,16 @@ vkdev_ext\num:
.else

.macro PhysDevExtTramp num
#if defined(_WIN32)
.global "_vkPhysDevExtTramp\num\()@4"
"_vkPhysDevExtTramp\num\()@4":
#else
.global vkPhysDevExtTramp\num
#if defined(__ELF__)
.hidden vkPhysDevExtTramp\num
#endif
vkPhysDevExtTramp\num:
#endif
_CET_ENDBR
mov eax, [esp + 4] # Load the wrapped VkPhysicalDevice into eax
mov ecx, [eax + PHYS_DEV_OFFSET_PHYS_DEV_TRAMP] # Load the unwrapped VkPhysicalDevice into ecx
Expand All @@ -102,11 +107,16 @@ vkPhysDevExtTramp\num:
.endm

.macro PhysDevExtTermin num
#if defined(_WIN32)
.global "_vkPhysDevExtTermin\num\()@4"
"_vkPhysDevExtTermin\num\()@4":
#else
.global vkPhysDevExtTermin\num
#if defined(__ELF__)
.hidden vkPhysDevExtTermin\num
#endif
vkPhysDevExtTermin\num:
#endif
_CET_ENDBR
mov ecx, [esp + 4] # Move the wrapped VkPhysicalDevice into ecx
mov eax, [ecx + ICD_TERM_OFFSET_PHYS_DEV_TERM] # Store the loader_icd_term* in eax
Expand All @@ -121,18 +131,27 @@ terminError\num:
push 0 # Push zero (third arg)
push VULKAN_LOADER_ERROR_BIT # Push the error logging bit (second arg)
push eax # Push the loader_instance (first arg)
#if defined(_WIN32)
call _loader_log_asm_function_not_supported # Log the error message before we crash
#else
call loader_log_asm_function_not_supported # Log the error message before we crash
#endif
add esp, 20 # Clean up the args
mov eax, 0
jmp eax # Crash intentionally by jumping to address zero
.endm

.macro DevExtTramp num
#if defined(_WIN32)
.global "_vkdev_ext\num\()@4"
"_vkdev_ext\num\()@4":
#else
.global vkdev_ext\num
#if defined(__ELF__)
.hidden vkdev_ext\num
#endif
vkdev_ext\num:
#endif
_CET_ENDBR
mov eax, dword ptr [esp + 4] # Dereference the handle to get the dispatch table
mov eax, dword ptr [eax] # Dereference the chain_device to get the loader_dispatch
Expand Down
Loading