Added workarounds for clang with W32 and MinGW incorrect headers

2 files changed, 45 insertions, 13 deletions

diff --git a/configure.ac b/configure.ac
index 6a13f469..4f9b3f45 100644
--- a/configure.ac
+++ b/configure.ac
@@ -325,7 +325,7 @@ AS_CASE([${enable_build_type}],[debug|debugger],
     MHD_CHECK_ADD_CC_CFLAGS([-Wextra -Wdouble-promotion], [CFLAGS_ac])
     MHD_FIND_ADD_CC_CFLAG_IFELSE(
       [
-        # clang produce warning when string pointer is used as a formar for v*printf() function
+        # clang produce warning when string pointer is used as a format specifier for v*printf() function
         AS_VAR_IF([mhd_cv_cc_clang_based],["yes"],[MHD_CHECK_ADD_CC_CFLAG([-Wno-format-nonliteral], [CFLAGS_ac])])
       ],[],
       [CFLAGS_ac], [-Wformat=2], [-Wformat]
@@ -359,7 +359,39 @@ AS_CASE([${enable_build_type}],[debug|debugger],
     MHD_CHECK_ADD_CC_CFLAGS([-Wmissing-noreturn -Wmissing-variable-declarations -Wnested-anon-types], [CFLAGS_ac])
     MHD_CHECK_ADD_CC_CFLAGS([-Wnewline-eof -Wover-aligned -Wredundant-parens], [CFLAGS_ac])
     MHD_CHECK_ADD_CC_CFLAGS([-Wshift-sign-overflow -Wtautological-compare -Wunaligned-access], [CFLAGS_ac])
-    MHD_CHECK_ADD_CC_CFLAGS([-Wunused -Wused-but-marked-unused -Wzero-as-null-pointer-constant -Wzero-length-array], [CFLAGS_ac])
+    MHD_CHECK_ADD_CC_CFLAGS([-Wunused -Wzero-as-null-pointer-constant -Wzero-length-array], [CFLAGS_ac])
+    MHD_CHECK_CC_CFLAG([-Wused-but-marked-unused],[CFLAGS_ac],
+      [
+        AC_CACHE_CHECK([whether $[]CC -Wused-but-marked-unused works with system headers],
+          [mhd_cv_wused_but_marked_unused_sys_header],
+          [
+            SAVE_ac_c_werror_flag="$ac_c_werror_flag"
+            ac_c_werror_flag="yes"
+            CFLAGS="${CFLAGS_ac} -Wused-but-marked-unused ${user_CFLAGS}"
+            AC_COMPILE_IFELSE(
+              [
+                AC_LANG_SOURCE([[
+#include <stdio.h>
+
+int main(void)
+{
+  char buf[16];
+  return (int) snprintf(buf, 16, "test");
+}
+                  ]]
+                )
+              ],
+              [mhd_cv_wused_but_marked_unused_sys_header="yes"],
+              [mhd_cv_wused_but_marked_unused_sys_header="no"]
+            )
+            ac_c_werror_flag="$SAVE_ac_c_werror_flag"
+          ]
+        )
+        AS_VAR_IF([mhd_cv_wused_but_marked_unused_sys_header],["yes"],
+          [MHD_APPEND_FLAG_TO_VAR([CFLAGS_ac],[-Wused-but-marked-unused])]
+        )
+      ]
+    )
     #
     # Removed flags:
     #
diff --git a/src/microhttpd/daemon.c b/src/microhttpd/daemon.c
index 29ce1ccc..b1cb5146 100644
--- a/src/microhttpd/daemon.c
+++ b/src/microhttpd/daemon.c
@@ -815,20 +815,20 @@ urh_from_fdset (struct MHD_UpgradeResponseHandle *urh,
 
   if (MHD_INVALID_SOCKET != conn_sckt)
   {
-    if (FD_ISSET (conn_sckt, rs))
+    if (FD_ISSET (conn_sckt, (fd_set *) _MHD_DROP_CONST (rs)))
       urh->app.celi |= MHD_EPOLL_STATE_READ_READY;
-    if (FD_ISSET (conn_sckt, ws))
+    if (FD_ISSET (conn_sckt, (fd_set *) _MHD_DROP_CONST (ws)))
       urh->app.celi |= MHD_EPOLL_STATE_WRITE_READY;
-    if (FD_ISSET (conn_sckt, es))
+    if (FD_ISSET (conn_sckt, (fd_set *) _MHD_DROP_CONST (es)))
       urh->app.celi |= MHD_EPOLL_STATE_ERROR;
   }
   if ((MHD_INVALID_SOCKET != mhd_sckt))
   {
-    if (FD_ISSET (mhd_sckt, rs))
+    if (FD_ISSET (mhd_sckt, (fd_set *) _MHD_DROP_CONST (rs)))
       urh->mhd.celi |= MHD_EPOLL_STATE_READ_READY;
-    if (FD_ISSET (mhd_sckt, ws))
+    if (FD_ISSET (mhd_sckt, (fd_set *) _MHD_DROP_CONST (ws)))
       urh->mhd.celi |= MHD_EPOLL_STATE_WRITE_READY;
-    if (FD_ISSET (mhd_sckt, es))
+    if (FD_ISSET (mhd_sckt, (fd_set *) _MHD_DROP_CONST (es)))
       urh->mhd.celi |= MHD_EPOLL_STATE_ERROR;
   }
 }
@@ -4299,7 +4299,7 @@ internal_run_from_select (struct MHD_Daemon *daemon,
      will trigger select again and will be processed */
   if ( (MHD_ITC_IS_VALID_ (daemon->itc)) &&
        (FD_ISSET (MHD_itc_r_fd_ (daemon->itc),
-                  read_fd_set)) )
+                  (fd_set *) _MHD_DROP_CONST (read_fd_set))) )
     MHD_itc_clear_ (daemon->itc);
 
   /* Process externally added connection if any */
@@ -4310,7 +4310,7 @@ internal_run_from_select (struct MHD_Daemon *daemon,
   if ( (MHD_INVALID_SOCKET != (ds = daemon->listen_fd)) &&
        (! daemon->was_quiesced) &&
        (FD_ISSET (ds,
-                  read_fd_set)) )
+                  (fd_set *) _MHD_DROP_CONST (read_fd_set))) )
     (void) MHD_accept_connection (daemon);
 
   if (0 == (daemon->options & MHD_USE_THREAD_PER_CONNECTION))
@@ -4325,11 +4325,11 @@ internal_run_from_select (struct MHD_Daemon *daemon,
         continue;
       call_handlers (pos,
                      FD_ISSET (ds,
-                               read_fd_set),
+                               (fd_set *) _MHD_DROP_CONST (read_fd_set)),
                      FD_ISSET (ds,
-                               write_fd_set),
+                               (fd_set *) _MHD_DROP_CONST (write_fd_set)),
                      FD_ISSET (ds,
-                               except_fd_set));
+                               (fd_set *) _MHD_DROP_CONST (except_fd_set)));
     }
   }