reduce OS ifdefs, refactor getting dirs and filenames from paths to files

backends/cxxrtl/cxxrtl_backend.cc

@@ -637,20 +637,6 @@ std::string escape_cxx_string(const std::string &input)
 	return output;
 }
 
-std::string basename(const std::string &filepath)
-{
-#ifdef _WIN32
-	const std::string dir_seps = "\\/";
-#else
-	const std::string dir_seps = "/";
-#endif
-	size_t sep_pos = filepath.find_last_of(dir_seps);
-	if (sep_pos != std::string::npos)
-		return filepath.substr(sep_pos + 1);
-	else
-		return filepath;
-}
-
 template<class T>
 std::string get_hdl_name(T *object)
 {
@@ -2841,7 +2827,7 @@ struct CxxrtlWorker {
 		}
 
 		if (split_intf)
-			f << "#include \"" << basename(intf_filename) << "\"\n";
+			f << "#include \"" << name_from_file_path(intf_filename) << "\"\n";
 		else
 			f << "#include <cxxrtl/cxxrtl.h>\n";
 		f << "\n";

frontends/ast/simplify.cc

@@ -4440,12 +4440,7 @@ AstNode *AstNode::readmem(bool is_readmemh, std::string mem_filename, AstNode *m
 	std::ifstream f;
 	f.open(mem_filename.c_str());
 	if (f.fail()) {
-#ifdef _WIN32
-		char slash = '\\';
-#else
-		char slash = '/';
-#endif
-		std::string path = filename.substr(0, filename.find_last_of(slash)+1);
+		std::string path = parent_from_file_path(filename);
 		f.open(path + mem_filename.c_str());
 		yosys_input_files.insert(path + mem_filename);
 	} else {

frontends/verilog/preproc.cc

@@ -892,11 +892,7 @@ frontend_verilog_preproc(std::istream                 &f,
 				// if the include file was not found, it is not given with an absolute path, and the
 				// currently read file is given with a path, then try again relative to its directory
 				ff.clear();
-#ifdef _WIN32
-				fixed_fn = filename.substr(0, filename.find_last_of("/\\")+1) + fn;
-#else
-				fixed_fn = filename.substr(0, filename.rfind('/')+1) + fn;
-#endif
+				fixed_fn = parent_from_file_path(filename) + fn;
 				ff.open(fixed_fn);
 			}
 			if (ff.fail() && fn.size() > 0 && fn_relative) {

kernel/yosys.cc

@@ -540,6 +540,25 @@ std::string escape_filename_spaces(const std::string& filename)
 	return out;
 }
 
+#ifdef _WIN32
+const char* const OS_PATH_SEP = "/\\";
+#else
+const char* const OS_PATH_SEP = "/";
+#endif
+
+std::string name_from_file_path(std::string path) {
+	size_t sep_pos = path.find_last_of(OS_PATH_SEP);
+	if (sep_pos != std::string::npos)
+		return path.substr(sep_pos + 1);
+	else
+		return path;
+}
+
+// Includes OS_PATH_SEP at the end if present
+std::string parent_from_file_path(std::string path) {
+	return path.substr(0, path.find_last_of(OS_PATH_SEP)+1);
+}
+
 bool already_setup = false;
 
 void yosys_setup()

kernel/yosys_common.h

@@ -343,6 +343,8 @@ bool is_absolute_path(std::string filename);
 void remove_directory(std::string dirname);
 bool create_directory(const std::string& dirname);
 std::string escape_filename_spaces(const std::string& filename);
+std::string name_from_file_path(std::string path);
+std::string parent_from_file_path(std::string path);
 
 template<typename T> int GetSize(const T &obj) { return obj.size(); }
 inline int GetSize(RTLIL::Wire *wire);