Implement PosixEnv::GetRuntimePath to enable AutoEP tests on Linux/MacOS

cmake/onnxruntime_unittests.cmake

@@ -1979,7 +1979,7 @@ endif()
 # Build library that can be used with RegisterExecutionProviderLibrary and automatic EP selection
 # We need a shared lib build to use that as a dependency for the test library
 # Currently we only have device discovery on Windows so no point building the test app on other platforms.
-if (WIN32 AND onnxruntime_BUILD_SHARED_LIB AND
+if (onnxruntime_BUILD_SHARED_LIB AND
     NOT CMAKE_SYSTEM_NAME STREQUAL "Emscripten" AND
     NOT onnxruntime_MINIMAL_BUILD)
   # example_plugin_ep

onnxruntime/core/platform/posix/env.cc

@@ -26,6 +26,7 @@ limitations under the License.
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <filesystem>
 #if !defined(_AIX)
 #include <sys/syscall.h>
 #endif
@@ -592,6 +593,31 @@ class PosixEnv : public Env {
     return val == NULL ? std::string() : std::string(val);
   }
 
+  // Return the path of the executable/shared library for the current running code. This is to make it
+  // possible to load other shared libraries installed next to our core runtime code.
+  PathString GetRuntimePath() const override {
+    Dl_info dl_info{};
+    // Must be one of the symbols exported in libonnxruntime.{so,dynlib}.
+    void* symbol_from_this_library = dlsym(RTLD_DEFAULT, "OrtGetApiBase");
+    PathString runtime_path;
+    // We will find OrtGetApiBase if onnxruntime is loaded as a shared library
+    if (dladdr(symbol_from_this_library, &dl_info) && dl_info.dli_fname) {
+      // Converting to absolute path since running a program with and without gdb attached can make a difference whether
+      // dli_fname will be absolute or relative. Converting to absolute for consistent result
+      runtime_path = PathString(std::filesystem::absolute(std::filesystem::path(dl_info.dli_fname).parent_path().string())) + "/";
+    } else {
+      // else use path of current executable to mirror Windows behavior
+#if __linux__
+      runtime_path = PathString(std::filesystem::absolute(std::filesystem::read_symlink(std::filesystem::path("/proc/self/exe")).parent_path())) + "/";
+#else
+      // TODO: MacOS could use _NSGetExecutablePath, but this needs to be tested!
+      runtime_path = PathString();
+#endif
+    }
+    LOGS_DEFAULT(VERBOSE) << "Determined PosixEnv runtime path as \"" << runtime_path << "\"";
+    return runtime_path;
+  }
+
  private:
   Telemetry telemetry_provider_;
 #ifdef ORT_USE_CPUINFO

onnxruntime/core/providers/cuda/version_script.lds

@@ -2,6 +2,8 @@
 VERS_1.0 {
   global:
     GetProvider;
+    CreateEpFactories;
+    ReleaseEpFactory;
     _binary_*;
 
   # Hide everything else.

onnxruntime/test/autoep/test_selection.cc

@@ -1,8 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-// registration/selection is only supported on windows as there's no device discovery on other platforms
-#ifdef _WIN32
 
 #include <filesystem>
 // #include <absl/base/config.h>
@@ -171,7 +169,11 @@ TEST(AutoEpSelection, CpuEP) {
 TEST(AutoEpSelection, CudaEP) {
   Ort::KeyValuePairs provider_options;
   provider_options.Add("prefer_nhwc", "1");
-  RunBasicTest(kCudaExecutionProvider, "onnxruntime_providers_cuda", provider_options);
+#if __linux__
+  RunBasicTest(kCudaExecutionProvider, "libonnxruntime_providers_cuda.so", provider_options);
+#else
+  RunBasicTest(kCudaExecutionProvider, "onnxruntime_providers_cuda.dll", provider_options);
+#endif
 }
 #endif
 
@@ -502,5 +504,3 @@ TEST(AutoEpSelection, PolicyDelegateReturnsError) {
 
 }  // namespace test
 }  // namespace onnxruntime
-
-#endif  // _WIN32