Move all platform dependent headers and code to util.cpp module (#5106)

src/util.cpp

@@ -14,10 +14,31 @@
  * limitations under the License.
  */
 
-#include <clocale>
+// clang-format off
+// Dont't remove `format off`, it prevent reordering of win-includes.
+#ifdef _WIN32
+#  ifndef WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
+#  endif
+#  ifndef NOMINMAX
+#    define NOMINMAX
+#  endif
+#  include <windows.h>  // Must be included before <direct.h>
+#  include <direct.h>
+#  include <winbase.h>
+#  undef interface  // This is also important because of reasons
+#else
+#  include <limits.h>
+#endif
+// clang-format on
 
+#include "flatbuffers/base.h"
 #include "flatbuffers/util.h"
 
+#include <sys/stat.h>
+#include <clocale>
+#include <fstream>
+
 namespace flatbuffers {
 
 bool FileExistsRaw(const char *name) {
@@ -88,6 +109,97 @@ FileExistsFunction SetFileExistsFunction(
   return previous_function;
 }
 
+bool SaveFile(const char *name, const char *buf, size_t len, bool binary) {
+  std::ofstream ofs(name, binary ? std::ofstream::binary : std::ofstream::out);
+  if (!ofs.is_open()) return false;
+  ofs.write(buf, len);
+  return !ofs.bad();
+}
+
+// We internally store paths in posix format ('/'). Paths supplied
+// by the user should go through PosixPath to ensure correct behavior
+// on Windows when paths are string-compared.
+
+static const char kPathSeparatorWindows = '\\';
+static const char *PathSeparatorSet = "\\/";  // Intentionally no ':'
+
+std::string StripExtension(const std::string &filepath) {
+  size_t i = filepath.find_last_of(".");
+  return i != std::string::npos ? filepath.substr(0, i) : filepath;
+}
+
+std::string GetExtension(const std::string &filepath) {
+  size_t i = filepath.find_last_of(".");
+  return i != std::string::npos ? filepath.substr(i + 1) : "";
+}
+
+std::string StripPath(const std::string &filepath) {
+  size_t i = filepath.find_last_of(PathSeparatorSet);
+  return i != std::string::npos ? filepath.substr(i + 1) : filepath;
+}
+
+std::string StripFileName(const std::string &filepath) {
+  size_t i = filepath.find_last_of(PathSeparatorSet);
+  return i != std::string::npos ? filepath.substr(0, i) : "";
+}
+
+std::string ConCatPathFileName(const std::string &path,
+                               const std::string &filename) {
+  std::string filepath = path;
+  if (filepath.length()) {
+    char &filepath_last_character = string_back(filepath);
+    if (filepath_last_character == kPathSeparatorWindows) {
+      filepath_last_character = kPathSeparator;
+    } else if (filepath_last_character != kPathSeparator) {
+      filepath += kPathSeparator;
+    }
+  }
+  filepath += filename;
+  // Ignore './' at the start of filepath.
+  if (filepath[0] == '.' && filepath[1] == kPathSeparator) {
+    filepath.erase(0, 2);
+  }
+  return filepath;
+}
+
+std::string PosixPath(const char *path) {
+  std::string p = path;
+  std::replace(p.begin(), p.end(), '\\', '/');
+  return p;
+}
+
+void EnsureDirExists(const std::string &filepath) {
+  auto parent = StripFileName(filepath);
+  if (parent.length()) EnsureDirExists(parent);
+    // clang-format off
+
+  #ifdef _WIN32
+    (void)_mkdir(filepath.c_str());
+  #else
+    mkdir(filepath.c_str(), S_IRWXU|S_IRGRP|S_IXGRP);
+  #endif
+  // clang-format on
+}
+
+std::string AbsolutePath(const std::string &filepath) {
+  // clang-format off
+
+  #ifdef FLATBUFFERS_NO_ABSOLUTE_PATH_RESOLUTION
+    return filepath;
+  #else
+    #ifdef _WIN32
+      char abs_path[MAX_PATH];
+      return GetFullPathNameA(filepath.c_str(), MAX_PATH, abs_path, nullptr)
+    #else
+      char abs_path[PATH_MAX];
+      return realpath(filepath.c_str(), abs_path)
+    #endif
+      ? abs_path
+      : filepath;
+  #endif // FLATBUFFERS_NO_ABSOLUTE_PATH_RESOLUTION
+  // clang-format on
+}
+
 // Locale-independent code.
 #if defined(FLATBUFFERS_LOCALE_INDEPENDENT) && \
     (FLATBUFFERS_LOCALE_INDEPENDENT > 0)
@@ -123,11 +235,10 @@ bool SetGlobalTestLocale(const char *locale_name, std::string *_value) {
   if (_value) *_value = std::string(the_locale);
   return true;
 }
-
-#ifdef _MSC_VER
-#  pragma warning(disable : 4996)  // _CRT_SECURE_NO_WARNINGS
-#endif
 bool ReadEnvironmentVariable(const char *var_name, std::string *_value) {
+  #ifdef _MSC_VER
+  __pragma(warning(disable : 4996)); // _CRT_SECURE_NO_WARNINGS
+  #endif
   auto env_str = std::getenv(var_name);
   if (!env_str) return false;
   if (_value) *_value = std::string(env_str);