Use std::experimental::filesystem instead of std::filesystem

CMakeLists.txt

@@ -16,6 +16,7 @@ message("Building onnxruntime-genai for version ${VERSION_INFO}")
 # Checking if CUDA is supported
 include(CheckLanguage)
 add_compile_definitions(BUILDING_ORT_GENAI_C)
+
 if(USE_CUDA)
   check_language(CUDA)
   if(CMAKE_CUDA_COMPILER)

cmake/cxx_standard.cmake

@@ -9,4 +9,8 @@ elseif (USE_CUDA AND CMAKE_CUDA_COMPILER AND CMAKE_CUDA_COMPILER_VERSION VERSION
 else ()
     message("Test is using C++20")
     set(CMAKE_CXX_STANDARD 20)
-endif ()
+endif ()
+
+if ("${CMAKE_C_COMPILER_ID}" STREQUAL "GNU" AND CMAKE_C_COMPILER_VERSION VERSION_LESS 9)
+    add_compile_definitions(USE_EXPERIMENTAL_FILESYSTEM)
+endif()

src/config.cpp

@@ -397,7 +397,7 @@ struct RootObject_Element : JSON::Element {
   JSON::Element& t_;
 };
 
-void ParseConfig(const std::filesystem::path& filename, Config& config) {
+void ParseConfig(const fs::path& filename, Config& config) {
   std::ifstream file(filename, std::ios::binary | std::ios::ate);
   if (!file.is_open()) {
     throw std::runtime_error("Error opening " + filename.string());
@@ -421,7 +421,7 @@ void ParseConfig(const std::filesystem::path& filename, Config& config) {
   }
 }
 
-Config::Config(const std::filesystem::path& path) : config_path{path} {
+Config::Config(const fs::path& path) : config_path{path} {
   ParseConfig(path / "genai_config.json", *this);
 
   if (model.context_length == 0)

src/config.h

@@ -6,9 +6,9 @@ namespace Generators {
 
 struct Config {
   Config() = default;
-  Config(const std::filesystem::path& path);
+  Config(const fs::path& path);
 
-  std::filesystem::path config_path;  // Path of the config directory
+  fs::path config_path;  // Path of the config directory
 
   using ProviderOption = std::pair<std::string, std::string>;
   struct ProviderOptions {

src/filesystem.h

@@ -0,0 +1,11 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+// TODO(baijumeswani): Remove experimental when packaging pipeline can use GCC > 8
+#ifdef USE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include <filesystem>
+namespace fs = std::filesystem;
+#endif

src/generators.h

@@ -5,8 +5,9 @@
 #include <assert.h>
 #include <cmath>
 #include <cstring>
-#include <filesystem>
+#include "filesystem.h"
 #include <functional>
+#include <iostream>
 #include "span.h"
 #include <memory>
 #include <numeric>

src/logging.cpp

@@ -44,7 +44,7 @@ void SetLogString(std::string_view name, std::string_view value) {
     if (value.empty())
       gp_logfile.reset();
     else {
-      std::filesystem::path filename{value};
+      fs::path filename{std::string(value)};
       gp_logfile = std::make_unique<std::ofstream>(filename);
     }
 

src/models/model.cpp

@@ -297,7 +297,7 @@ void Model::CreateSessionOptions() {
   }
 
   if (options.enable_profiling.has_value()) {
-    std::filesystem::path profile_file_prefix{options.enable_profiling.value()};
+    fs::path profile_file_prefix{options.enable_profiling.value()};
     ort_options.EnableProfiling(profile_file_prefix.c_str());
   }
 

src/tokenizer/c_api/tfmtok_c.cc

@@ -2,7 +2,7 @@
 // Licensed under the MIT License.
 
 #include <cstdarg>
-#include <filesystem>
+#include "../filesystem.h"
 #include <algorithm>
 
 #include "tfmtok.h"
@@ -117,7 +117,7 @@ tfmError_t TFM_API_CALL TfmCreateTokenizer(TfmTokenizer** tokenizer,
     return kTfmErrorInvalidArgument;
   }
 
-  if (!std::filesystem::is_directory(tokenizer_path)) {
+  if (!fs::is_directory(tokenizer_path)) {
     last_error_message = std::string("Cannot find the directory of ") + tokenizer_path;
     return kTfmErrorInvalidArgument;
   }

src/tokenizer/config.cc

@@ -4,7 +4,7 @@
 #include <string>
 #include <fstream>
 #include <streambuf>
-#include <filesystem>
+#include "../filesystem.h"
 
 #include "config.h"
 
@@ -68,8 +68,7 @@ TfmStatus TokenConfig::LoadJson(const std::string& json_path) {
   simdjson::dom::parser parser;
   simdjson::dom::element root;
 
-  if (!std::filesystem::exists(
-          std::filesystem::path(json_path).lexically_normal())) {
+  if (!fs::exists(fs::path(json_path))) {
     return {kTfmErrorInvalidFile, std::string(json_path) + " not found"};
   }
   std::string json_text = PatchJsonText(json_path);

src/tokenizer/tokenizer.cc

@@ -1,7 +1,7 @@
 #include "token_bpe.h"
 #include "token_rwkv.h"
 
-#include <filesystem>
+#include "../filesystem.h"
 #include <memory>
 
 namespace tfm {
@@ -30,7 +30,7 @@ TfmStatus CreateBPETokenizer(const std::string& tokenizer_path,
   if (type.empty()) {
     if (BPETokenizer::IsSupportedModel(GetModelName(token_cfg->tokenizer_class_))) {
       type = "BPE";
-    } /* else if (std::filesystem::exists(tokenizer_path + "/tokenizer.model")) {
+    } /* else if (fs::exists(tokenizer_path + "/tokenizer.model")) {
       // if 'tokenizer.model exists in the tokenizer_path, then it is a sentencepiece model
       type = "SPM";
     } */ else {