remove __UNUSED

No need since we have C++17.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

configure.ac

@@ -72,11 +72,6 @@ AC_DEFINE(USER_AGENT, [std::string(PACKAGE "/" VERSION "/") + torrent::version()
 
 AC_CHECK_FUNCS(posix_memalign)
 
-CC_ATTRIBUTE_UNUSED(
-  AC_DEFINE([__UNUSED], [__attribute__((unused))], [Wrapper around unused attribute]),
-  AC_DEFINE([__UNUSED], [], [Null-wrapper if unused attribute is unsupported])
-)
-
 dnl Only update global build variables immediately before generating the output,
 dnl to avoid affecting the global build environment for other autoconf checks.
 LIBS="$PTHREAD_LIBS $CURSES_LIB $CURSES_LIBS $LIBCURL $LIBCURL_LIBS $DEPENDENCIES_LIBS $LIBS"

rak/string_manip.h

@@ -143,8 +143,8 @@ public:
     return *this;
   }
 
-  bool operator == (__UNUSED const split_iterator_t& itr) const { return m_pos == m_seq->end(); }
+  bool operator == (const split_iterator_t&) const { return m_pos == m_seq->end(); }
-  bool operator != (__UNUSED const split_iterator_t& itr) const { return m_pos != m_seq->end(); }
+  bool operator != (const split_iterator_t&) const { return m_pos != m_seq->end(); }
 
 private:
   const Sequence* m_seq;
@@ -161,7 +161,7 @@ split_iterator(const Sequence& seq, typename Sequence::value_type delim) {
 
 template <typename Sequence>
 inline split_iterator_t<Sequence>
-split_iterator(__UNUSED const Sequence& seq) {
+split_iterator(const Sequence&) {
   return split_iterator_t<Sequence>();
 }
 

scripts/attributes.m4

@@ -107,25 +107,6 @@ AC_DEFUN([CC_ATTRIBUTE_NONNULL], [
 	fi
 ])
 
-AC_DEFUN([CC_ATTRIBUTE_UNUSED], [
-	AC_CACHE_CHECK([if compiler supports __attribute__((unused))],
-		[cc_cv_attribute_unused],
-		[AC_COMPILE_IFELSE([AC_LANG_SOURCE([
-			void some_function(void *foo, __attribute__((unused)) void *bar);
-			])],
-			[cc_cv_attribute_unused=yes],
-			[cc_cv_attribute_unused=no])
-		])
-	
-	if test "x$cc_cv_attribute_unused" = "xyes"; then
-		AC_DEFINE([SUPPORT_ATTRIBUTE_UNUSED], 1, [Define this if the compiler supports the unused attribute])
-		$1
-	else
-		true
-		$2
-	fi
-])
-
 AC_DEFUN([CC_FUNC_EXPECT], [
 	AC_CACHE_CHECK([if compiler has __builtin_expect function],
 		[cc_cv_func_expect],

src/display/canvas.h

@@ -136,7 +136,8 @@ Canvas::resize_term(std::pair<int, int> dim) {
 
 inline unsigned int
 Canvas::get_x() {
-  int x, __UNUSED y;
+  int x;
+  [[maybe_unused]] int y;
   if (!m_isDaemon) {
     getyx(m_window, y, x);
   } else {
@@ -158,7 +159,8 @@ Canvas::get_y() {
 
 inline unsigned int
 Canvas::width() {
-  int x, __UNUSED y;
+  int x;
+  [[maybe_unused]] int y;
   if (!m_isDaemon) {
     getmaxyx(m_window, y, x);
   } else {
@@ -259,7 +261,8 @@ Canvas::set_default_attributes(int attr) {
 
 inline int
 Canvas::get_screen_width() {
-  int x, __UNUSED y;
+  int x;
+  [[maybe_unused]] int y;
   if (!m_isDaemon) {
     getmaxyx(stdscr, y, x);
   } else {

src/rpc/exec_file.cc

@@ -19,7 +19,7 @@ namespace rpc {
 int
 ExecFile::execute(const char* file, char* const* argv, int flags) {
   // Write the execued command and its parameters to the log fd.
-  int __UNUSED result;
+  [[maybe_unused]] int result;
 
   if (m_log_fd != -1) {
     for (char* const* itr = argv; *itr != NULL; itr++) {
@@ -89,7 +89,7 @@ ExecFile::execute(const char* file, char* const* argv, int flags) {
     for (int i = 3, last = sysconf(_SC_OPEN_MAX); i != last; i++)
       ::close(i);
 
-    int result = execvp(file, argv);
+    result = execvp(file, argv);
 
     _exit(result);
   }

src/rpc/scgi_task.cc

@@ -165,7 +165,7 @@ SCgiTask::event_read() {
   torrent::this_thread::poll()->remove_read(this);
 
   if (m_parent->log_fd() >= 0) {
-    int __UNUSED result;
+    [[maybe_unused]] int result;
 
     // Clean up logging, this is just plain ugly...
     //    write(m_logFd, "\n---\n", sizeof("\n---\n"));
@@ -326,7 +326,7 @@ SCgiTask::receive_write(const char* buffer, uint32_t length) {
   std::memcpy(m_buffer + headerSize, buffer, length);
 
   if (m_parent->log_fd() >= 0) {
-    int result [[maybe_unused]];
+    [[maybe_unused]] int result;
     result = write(m_parent->log_fd(), m_buffer, m_buffer_size);
     result = write(m_parent->log_fd(), "\n---\n", sizeof("\n---\n"));
   }

src/rpc/xmlrpc.cc

@@ -14,10 +14,10 @@ namespace rpc {
 void XmlRpc::initialize() {}
 void XmlRpc::cleanup() {}
 
-void XmlRpc::insert_command(__UNUSED const char* name, __UNUSED const char* parm, __UNUSED const char* doc) {}
+void XmlRpc::insert_command(const char*, const char*, const char*) {}
-void XmlRpc::set_dialect(__UNUSED int dialect) {}
+void XmlRpc::set_dialect(int) {}
 
-bool XmlRpc::process(__UNUSED const char* inBuffer, __UNUSED uint32_t length, __UNUSED slot_write slotWrite) { return false; }
+bool XmlRpc::process(const char*, uint32_t, slot_write) { return false; }
 
 int64_t XmlRpc::size_limit() { return 0; }
 void    XmlRpc::set_size_limit(uint64_t size) {}

src/utils/lockfile.cc

@@ -100,7 +100,7 @@ Lockfile::try_lock() {
   if (pos == 0) {
     ssize_t len = std::strlen(buf);
     ::snprintf(buf + len, 255 - len, ":+%i\n", ::getpid());
-    int __UNUSED result = ::write(fd, buf, std::strlen(buf));
+    [[maybe_unused]] int result = ::write(fd, buf, std::strlen(buf));
   }
 
   ::close(fd);