vsmigx/{CMakeLists.txt,win32.cpp},.github/workflows/windows-migx.yml:…

… delay load migx

vsmigx/CMakeLists.txt

@@ -9,7 +9,7 @@ set(VAPOURSYNTH_INCLUDE_DIRECTORY "" CACHE PATH "Path to VapourSynth headers")
 find_package(migraphx REQUIRED CONFIG)
 find_package(hip REQUIRED CONFIG)
 
-add_library(vsmigx SHARED vs_migraphx.cpp)
+add_library(vsmigx SHARED vs_migraphx.cpp win32.cpp)
 
 target_include_directories(vsmigx PRIVATE ${VAPOURSYNTH_INCLUDE_DIRECTORY})
 
@@ -22,6 +22,14 @@ set_target_properties(vsmigx PROPERTIES
     CXX_STANDARD_REQUIRED ON
 )
 
+if (WIN32)
+    target_link_options(vsmigx PRIVATE
+        "/DELAYLOAD:migraphx_c.dll"
+        "/DELAYLOAD:amdhip64_6.dll"
+        "delayimp.lib"
+    )
+endif()
+
 find_package(Git REQUIRED)
 execute_process(
     COMMAND ${GIT_EXECUTABLE} describe --tags --long --always

vsmigx/win32.cpp

@@ -0,0 +1,95 @@
+#ifdef _MSC_VER
+#include <windows.h>
+#include <delayimp.h>
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <filesystem>
+
+#define DLL_DIR L"vsmlrt-hip"
+
+#include <iostream>
+
+namespace {
+std::vector<std::wstring> dlls = {
+    // This list must be sorted by dependency.
+    L"amdhip64_6.dll",
+    L"migraphx.dll",
+    L"migraphx_tf.dll",
+    L"migraphx_onnx.dll",
+    L"migraphx_c.dll", // must be the last
+};
+
+namespace fs = std::filesystem;
+static fs::path dllDir() {
+    static const std::wstring res = []() -> std::wstring {
+        HMODULE mod = 0;
+        if (GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, (char *)dllDir, &mod)) {
+            std::vector<wchar_t> buf;
+            size_t n = 0;
+            do {
+                buf.resize(buf.size() + MAX_PATH);
+                n = GetModuleFileNameW(mod, buf.data(), buf.size());
+            } while (n >= buf.size());
+            buf.resize(n);
+            std::wstring path(buf.begin(), buf.end());
+            return path;
+        }
+        throw std::runtime_error("unable to locate myself");
+    }();
+    return fs::path(res).parent_path();
+}
+
+FARPROC loadDLLs() {
+    fs::path dir = dllDir() / DLL_DIR;
+    HMODULE h = nullptr;
+    for (const auto dll: dlls) {
+        fs::path p = dir / dll;
+        std::wstring s = p;
+        h = LoadLibraryW(s.c_str());
+        if (getenv("VSMIGX_VERBOSE"))
+            std::wcerr << L"vsmigx: preloading " << p << L": " << h << std::endl;
+        if (!h)
+            std::wcerr << L"vsmigx: failed to preload " << s << std::endl;
+    }
+    return (FARPROC)h;
+}
+
+extern "C" FARPROC WINAPI delayload_hook(unsigned reason, DelayLoadInfo* info) {
+    switch (reason) {
+    case dliNoteStartProcessing:
+    case dliNoteEndProcessing:
+        // Nothing to do here.
+        break;
+    case dliNotePreLoadLibrary:
+        //std::cerr << "loading " << info->szDll << std::endl;
+        if (std::string(info->szDll).find("migraphx_c.dll") != std::string::npos ||
+            std::string(info->szDll).find("amdhip64_6.dll") != std::string::npos
+        )
+            return loadDLLs();
+        break;
+    case dliNotePreGetProcAddress:
+        // Nothing to do here.
+        break;
+    case dliFailLoadLib:
+    case dliFailGetProc:
+        // Returning NULL from error notifications will cause the delay load
+        // runtime to raise a VcppException structured exception, that some code
+        // might want to handle.
+        return NULL;
+        break;
+    default:
+        abort(); // unreachable.
+        break;
+    }
+    // Returning NULL causes the delay load machinery to perform default
+    // processing for this notification.
+    return NULL;
+}
+} // namespace
+
+extern "C" {
+    const PfnDliHook __pfnDliNotifyHook2 = delayload_hook;
+    const PfnDliHook __pfnDliFailureHook2 = delayload_hook;
+};
+#endif