dynamic vulkan loading on apple platforms, honor VK_DRIVER_FILES env #6499

nihui · 2026-01-09T11:51:56Z

link moltenvk, run on swiftshader
tbd
update doc

tencent-adm · 2026-01-09T11:52:14Z

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codecov-commenter · 2026-01-09T11:54:53Z

Codecov Report

❌ Patch coverage is 85.71429% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.08%. Comparing base (41187d4) to head (42bbeb2).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
src/simplevk.cpp	85.71%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6499      +/-   ##
==========================================
+ Coverage   92.76%   93.08%   +0.31%     
==========================================
  Files         807      807              
  Lines      255091   255844     +753     
==========================================
+ Hits       236633   238147    +1514     
+ Misses      18458    17697     -761

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Copilot

Pull request overview

This pull request enables dynamic Vulkan loading on Apple platforms and adds support for the VK_DRIVER_FILES environment variable. Previously, Apple platforms only supported static Vulkan linkage; this change makes dynamic loading the primary method with static linkage as a fallback option.

Key changes:

Moved helper functions (get_driver_path_from_icd, get_driver_path_from_icd_env, get_driver_path_from_ncnn_env) outside of platform-specific conditional blocks to make them available on all platforms
Added VK_DRIVER_FILES environment variable support alongside VK_ICD_FILENAMES
Added Apple-specific well-known Vulkan driver paths (libMoltenVK.dylib, libvulkan_kosmickrisp.dylib)

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src/simplevk.cpp

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 6 comments.

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Copilot · 2026-01-10T14:09:56Z

src/simplevk.cpp

        };
+#elif __APPLE__
+        const char* well_known_path[] = {
+            "libMoltenVK.dylib",


The well-known path entry "libvulkan_kosmickrisp.dylib" appears to be a non-standard or test/development library name. If this is a legitimate Vulkan implementation, it should be documented. If it's for testing purposes only, consider adding a comment explaining its purpose. The unusual name "kosmickrisp" may confuse future maintainers.

Suggested change

"libMoltenVK.dylib",

"libMoltenVK.dylib",

// Non-standard/internal Vulkan implementation used as an additional fallback on Apple platforms.

Copilot · 2026-01-10T14:09:56Z

src/simplevk.cpp

+        int nscan = sscanf(line, " \"library_path\" : \"%255[^\"]\"", path);
+        if (nscan == 1)
+        {
+            if (path[0] == '.' || (path[0] != '/' && !strchr(path, ':') && (strchr(path, '/') || strchr(path, '\\'))))


The path detection logic has a complex condition that may not correctly identify all relative paths. The condition path[0] != '/' && !strchr(path, ':') && (strchr(path, '/') || strchr(path, '\\')) will miss paths like "subdir/file" that don't start with '.' but are still relative. Consider simplifying the logic: paths starting with '.' are relative, paths starting with '/' (or containing ':' on Windows for absolute paths like C:) are absolute, and all other paths could be treated as filenames that should be searched relative to the ICD file location or in system paths.

Suggested change

if (path[0] == '.' || (path[0] != '/' && !strchr(path, ':') && (strchr(path, '/') || strchr(path, '\\'))))

bool is_absolute = (path[0] == '/' || path[0] == '\\' || strchr(path, ':'));

if (!is_absolute)

Copilot · 2026-01-10T14:09:57Z

src/simplevk.cpp

+{
+    if (::vkGetInstanceProcAddr == NULL)
+    {
+        NCNN_LOGE("no static linked moltenvk");


The error message "no static linked moltenvk" is grammatically incorrect. It should be "no statically linked moltenvk" or "MoltenVK not statically linked".

Suggested change

NCNN_LOGE("no static linked moltenvk");

NCNN_LOGE("MoltenVK not statically linked");

.github/workflows/macos.yml

.github/workflows/release-python.yml

Copilot · 2026-01-10T14:09:58Z

src/simplevk.cpp

+    char line[256];
+    while (!feof(fp))
+    {
+        char* s = fgets(line, 256, fp);
+        if (!s)
+            break;
+
+        // "library_path": "path to driver library",
+        char path[256];
+        int nscan = sscanf(line, " \"library_path\" : \"%255[^\"]\"", path);


The fixed-size buffers 'line' and 'path' (both 256 bytes) could potentially overflow if the ICD JSON file contains very long library paths. While the sscanf format string limits to 255 characters, JSON files in the wild could have paths longer than this. Consider using dynamic allocation or a larger buffer size, or add proper error handling for truncated paths.

dynamic vulkan loading on apple platforms, honor VK_DRIVER_FILES env

192f33f

github-actions bot added the core label Jan 9, 2026

f

211c927

nihui mentioned this pull request Jan 9, 2026

Request: Support new Mesa KosmicKrisp for Apple devices in prebuilt vkpeak MacOS releases.. (vkpeak binary using vulkan loader libvulkan.dylib for MacOS) nihui/vkpeak#33

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nihui requested a review from Copilot January 9, 2026 12:07

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nihui and others added 10 commits January 9, 2026 21:51

Update Vulkan library path in macOS workflow

9845873

update moltenvk

edd8a0d

test2

3902b3d

w

de22379

weak import

e2b7280

r

117442d

link stub

372d5e2

z

e4d0853

use tbd

2700267

ppp

effe5d8

nihui requested a review from Copilot January 10, 2026 14:04

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nihui and others added 3 commits January 11, 2026 17:36

Merge branch 'master' into enhance-apple-vulkan-loader

96b8aae

doc

293d16f

f

42bbeb2

github-actions bot added the doc label Jan 11, 2026

nihui merged commit fe7c0cd into Tencent:master Jan 11, 2026
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dynamic vulkan loading on apple platforms, honor VK_DRIVER_FILES env #6499

dynamic vulkan loading on apple platforms, honor VK_DRIVER_FILES env #6499

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	"libMoltenVK.dylib",
	"libMoltenVK.dylib",
	// Non-standard/internal Vulkan implementation used as an additional fallback on Apple platforms.

	if (path[0] == '.' \|\| (path[0] != '/' && !strchr(path, ':') && (strchr(path, '/') \|\| strchr(path, '\\'))))
	bool is_absolute = (path[0] == '/' \|\| path[0] == '\\' \|\| strchr(path, ':'));
	if (!is_absolute)

	NCNN_LOGE("no static linked moltenvk");
	NCNN_LOGE("MoltenVK not statically linked");

dynamic vulkan loading on apple platforms, honor VK_DRIVER_FILES env #6499

dynamic vulkan loading on apple platforms, honor VK_DRIVER_FILES env #6499

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nihui commented Jan 9, 2026 •

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