Ugly workarounds to not depend on std::filesystem #7131

src/ifcparse/IfcFile.cpp

@@ -6,6 +6,10 @@
 #include <rocksdb/convenience.h>
 #endif
 
+#include <fstream>
+#include <sys/types.h>
+#include <sys/stat.h>
+
 IfcParse::parse_context::~parse_context() {
     for (auto& t : tokens_) {
         std::visit([](auto& v) {
@@ -570,23 +574,58 @@ IfcParse::IfcFile::~IfcFile() {
     }
 }
 
-#include <filesystem>
-#include <fstream>
+namespace {
+	// Utility functions for path handling in order not to rely on C++17's std::filesystem
+#ifdef _WIN32
+#define stat_t struct _stat
+    inline int stat_(const char* p, stat_t* s) { return ::_stat(p, s); }
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m) & _S_IFDIR) != 0)
+#endif
+#ifndef S_ISREG
+#define S_ISREG(m) (((m) & _S_IFREG) != 0)
+#endif
+#else
+    using stat_t = struct stat;
+    inline int stat_(const char* p, stat_t* s) { return ::stat(p, s); }
+#endif
+
+    inline bool path_exists_(const std::string& p, stat_t* out = nullptr) {
+        stat_t tmp;
+        stat_t* s = out ? out : &tmp;
+        return stat_(p.c_str(), s) == 0;
+    }
+
+    inline bool path_is_directory_(const stat_t& s) { return S_ISDIR(s.st_mode); }
+    inline bool path_is_regular_file_(const stat_t& s) { return S_ISREG(s.st_mode); }
+
+    inline std::string path_join_(const std::string& dir, const std::string& name) {
+        if (dir.empty()) return name;
+        const char last = dir.back();
+        if (last == '/' || last == '\\') return dir + name;
+#ifdef _WIN32
+        const char sep = '\\';
+#else
+        const char sep = '/';
+#endif
+        return dir + sep + name;
+    }
+} // namespace
 
 IfcParse::filetype IfcParse::guess_file_type(const std::string& fn) {
-    namespace fs = std::filesystem;
-
-    if (!fs::exists(fn)) {
+    stat_t st{};
+    if (!path_exists_(fn, &st)) {
         // @todo this is just weird, but for consistency with earlier behaviour
         // for now the only intent for this function is to auto-detect RocksDB
         return FT_IFCSPF;
     }
 
-    if (fs::is_directory(fn)) {
+    if (path_is_directory_(st)) {
         // Typical RocksDB file to look for
-        auto currentFile = fs::path(fn) / "CURRENT";
+        auto currentFile = path_join_(fn, "CURRENT");
+        stat_t cst{};
 
-        if (!fs::exists(currentFile) || !fs::is_regular_file(currentFile)) {
+        if (!path_exists_(currentFile, &cst) || !path_is_regular_file_(cst)) {
             return FT_UNKNOWN;
         }