vulkan: Fix weak symbol emulation when compiling with MSVC

Mapping unimplemented entrypoints to a global function pointer variable
initialized to NULL is a bit cumbersome, and actually led to a bug
in the vk_xxx_dispatch_table_from_entrypoints() template: the !override
case didn't have the right check on the source table entries. Instead of
fixing that case, let's simplify the logic by creating a stub function
and making the alternatename pragma point to this stub. This way we get
rid of all those uneeded xxx_Null symbols/variables and simplify the
tests in vk_xxxx_dispatch_table_from_entrypoints().

Cc: mesa-stable
Fixes: 98c622a96e ("vulkan: Update dispatch table gen for Windows")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13348>
This commit is contained in:
Boris Brezillon 2021-10-13 21:50:59 +02:00
parent ae99ea6f4d
commit 6d44b21d4f
2 changed files with 16 additions and 5 deletions

View file

@ -464,6 +464,13 @@ vk_device_entrypoint_is_enabled(int index, uint32_t core_version,
}
}
#ifdef _MSC_VER
void vk_entrypoint_stub(void)
{
unreachable(!"Entrypoint not implemented");
}
#endif
<%def name="dispatch_table_from_entrypoints(type)">
void vk_${type}_dispatch_table_from_entrypoints(
struct vk_${type}_dispatch_table *dispatch_table,
@ -477,8 +484,8 @@ void vk_${type}_dispatch_table_from_entrypoints(
memset(dispatch_table, 0, sizeof(*dispatch_table));
for (unsigned i = 0; i < ARRAY_SIZE(${type}_compaction_table); i++) {
#ifdef _MSC_VER
const uintptr_t zero = 0;
if (entry[i] == NULL || memcmp(entry[i], &zero, sizeof(zero)) == 0)
assert(entry[i] != NULL);
if (entry[i] == vk_entrypoint_stub)
#else
if (entry[i] == NULL)
#endif
@ -490,7 +497,12 @@ void vk_${type}_dispatch_table_from_entrypoints(
} else {
for (unsigned i = 0; i < ARRAY_SIZE(${type}_compaction_table); i++) {
unsigned disp_index = ${type}_compaction_table[i];
#ifdef _MSC_VER
assert(entry[i] != NULL);
if (disp[disp_index] == NULL && entry[i] != vk_entrypoint_stub)
#else
if (disp[disp_index] == NULL)
#endif
disp[disp_index] = entry[i];
}
}

View file

@ -123,13 +123,12 @@ TEMPLATE_C = Template(COPYRIGHT + """
% endif
% for p in prefixes:
#ifdef _MSC_VER
${e.return_type} (*${p}_${e.name}_Null)(${e.decl_params()}) = 0;
#ifdef _M_IX86
% for args_size in [4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 60, 104]:
#pragma comment(linker, "/alternatename:_${p}_${e.name}@${args_size}=_${p}_${e.name}_Null")
#pragma comment(linker, "/alternatename:_${p}_${e.name}@${args_size}=_vk_entrypoint_stub")
% endfor
#else
#pragma comment(linker, "/alternatename:${p}_${e.name}=${p}_${e.name}_Null")
#pragma comment(linker, "/alternatename:${p}_${e.name}=vk_entrypoint_stub")
#endif
#else
VKAPI_ATTR ${e.return_type} VKAPI_CALL ${p}_${e.name}(${e.decl_params()}) __attribute__ ((weak));