Fix getProgramPath() to find Python module in virtual environment on Windows and Linux

Utilities/FileSystem.h

@@ -12,6 +12,7 @@
 #else
 #include <unistd.h>
 #include <dirent.h>
+#include <dlfcn.h>
 #endif
 #ifdef __APPLE__
 #include <mach-o/dyld.h>
@@ -217,21 +218,77 @@ namespace Utilities
 
 		static std::string getProgramPath()
 		{
-			char buffer[1000];
-#ifdef WIN32	
-			GetModuleFileName(NULL, buffer, 1000);
+			std::string executablePath;
+			std::string dynamicModulePath;
+
+#ifdef WIN32
+			char exeBuffer[MAX_PATH] = { 0 };
+			if (GetModuleFileNameA(NULL, exeBuffer, MAX_PATH))
+				executablePath = exeBuffer;
+
+			HMODULE moduleHandle = nullptr;
+			if (GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+				reinterpret_cast<LPCSTR>(&getProgramPath), &moduleHandle) && moduleHandle)
+			{
+				char moduleBuffer[MAX_PATH] = { 0 };
+				if (GetModuleFileNameA(moduleHandle, moduleBuffer, MAX_PATH))
+					dynamicModulePath = moduleBuffer;
+			}
 #elif defined(__APPLE__)
-			uint32_t bufferSize = sizeof(buffer);
-			_NSGetExecutablePath(buffer, &bufferSize);
+			char exeBuffer[1024] = { 0 };
+			uint32_t bufferSize = sizeof(exeBuffer);
+			if (_NSGetExecutablePath(exeBuffer, &bufferSize) == 0)
+				executablePath = exeBuffer;
+
+			Dl_info moduleInfo{};
+			if (dladdr(reinterpret_cast<void*>(&getProgramPath), &moduleInfo) && moduleInfo.dli_fname)
+				dynamicModulePath = moduleInfo.dli_fname;
 #else
-			char szTmp[32];
-			sprintf(szTmp, "/proc/%d/exe", getpid());
-			int bytes = std::min((int)readlink(szTmp, buffer, 1000), 999);
-			buffer[bytes] = '\0';
+			char exeBuffer[1024] = { 0 };
+			char procPath[32];
+			sprintf(procPath, "/proc/%d/exe", getpid());
+			int exePathLength = std::min((int)readlink(procPath, exeBuffer, sizeof(exeBuffer) - 1), (int)(sizeof(exeBuffer) - 1));
+			if (exePathLength > 0)
+			{
+				exeBuffer[exePathLength] = '\0';
+				executablePath = exeBuffer;
+			}
+
+			Dl_info moduleInfo{};
+			if (dladdr(reinterpret_cast<void*>(&getProgramPath), &moduleInfo) && moduleInfo.dli_fname)
+				dynamicModulePath = moduleInfo.dli_fname;
 #endif
-			std::string::size_type pos = std::string(buffer).find_last_of("\\/");
-			return std::string(buffer).substr(0, pos);
 
+			auto getParentDirectory = [](const std::string &path) -> std::string
+			{
+				size_t lastSeparator = path.find_last_of("\\/");
+				return (lastSeparator != std::string::npos) ? path.substr(0, lastSeparator) : "";
+			};
+
+			// If running as a dynamic module / Python extension (module differs from executable)
+			if (!dynamicModulePath.empty() && dynamicModulePath != executablePath)
+			{
+				std::string searchDirectory = getParentDirectory(dynamicModulePath);
+
+				// Walk up the directory tree (up to 6 levels) to locate resources/data
+				for (int level = 0; level < 6 && !searchDirectory.empty(); ++level)
+				{
+					if (isDirectory(searchDirectory + "/resources") || isDirectory(searchDirectory + "/data"))
+						return searchDirectory;
+
+					if (isDirectory(searchDirectory + "/bin/resources") || isDirectory(searchDirectory + "/bin/data"))
+						return searchDirectory + "/bin";
+
+					searchDirectory = getParentDirectory(searchDirectory);
+				}
+
+				return getParentDirectory(dynamicModulePath);
+			}
+			else
+			{
+				// Standalone executable fallback
+				return getParentDirectory(executablePath);
+			}
 		}
 
 		static bool copyFile(const std::string &source, const std::string &dest)

setup.py

@@ -1,6 +1,7 @@
 import os
 import re
 import sys
+import sysconfig
 import platform
 import subprocess
 import multiprocessing as mp
@@ -50,11 +51,21 @@ def run(self):
     def build_extension(self, ext):
         extdir = os.path.abspath(os.path.dirname(self.get_ext_fullpath(ext.name)))
         bin_dir_windows = os.path.join(os.path.abspath(self.build_temp), "bin")
-        cmake_args = ['-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=' + extdir,
-                    #   '-DPYBIND11_PYTHON_VERSION=' + f"{sys.version_info.major}.{sys.version_info.minor}"
-                      '-DPYBIND11_FINDPYTHON=On',
-                      '-DPython_EXECUTABLE=' + sys.executable,
-                      ]
+        cmake_args = [
+            "-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=" + extdir,
+            "-DPYBIND11_FINDPYTHON=On",
+            "-DPython_EXECUTABLE=" + sys.executable,
+            "-DPython_INCLUDE_DIR=" + sysconfig.get_path("include"),
+        ]
+        if platform.system() == "Windows":
+            cmake_args.append(
+                "-DPython_LIBRARY="
+                + os.path.join(
+                    sys.base_prefix,
+                    "libs",
+                    f"python{sys.version_info.major}{sys.version_info.minor}.lib",
+                )
+            )
 
         print(f"Using cmake args {cmake_args}")
         print(f"Python version: {sys.version_info.major}.{sys.version_info.minor}.{sys.version_info.micro}")