From a993e6438eff1e5b71f1dcc97df478ca954aae9f Mon Sep 17 00:00:00 2001
From: Olaf Meeuwissen <paddy-hack@member.fsf.org>
Date: Sun, 22 Dec 2019 16:05:51 +0900
Subject: [PATCH 1/3] dll: Fix [-Wformat-truncation=] compiler warning

Per POSIX, `readdir` returns filenames that are at most `NAME_MAX` long.
---
 backend/dll.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/backend/dll.c b/backend/dll.c
index 926a08064..c88818c4f 100644
--- a/backend/dll.c
+++ b/backend/dll.c
@@ -799,7 +799,8 @@ read_dlld (void)
   DIR *dlld;
   struct dirent *dllconf;
   struct stat st;
-  char conffile[PATH_MAX], dlldir[PATH_MAX];
+  char dlldir[PATH_MAX];
+  char conffile[PATH_MAX + strlen("/") + NAME_MAX];
   size_t len, plen;
   const char *dir_list;
   char *copy, *next, *dir;
@@ -851,7 +852,7 @@ read_dlld (void)
           || (dllconf->d_name[len-1] == '#'))
         continue;
 
-      snprintf (conffile, PATH_MAX, "%s/%s", dlldir, dllconf->d_name);
+      snprintf (conffile, sizeof(conffile), "%s/%s", dlldir, dllconf->d_name);
 
       DBG (5, "sane_init/read_dlld: considering %s\n", conffile);
 

From e7f6c6e864200fc51a05c8eb5963a78b3251adbd Mon Sep 17 00:00:00 2001
From: Olaf Meeuwissen <paddy-hack@member.fsf.org>
Date: Sun, 22 Dec 2019 17:58:39 +0900
Subject: [PATCH 2/3] dll: Ignore [-Wcast-function-type] compiler warnings

---
 backend/dll.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/backend/dll.c b/backend/dll.c
index c88818c4f..39531bd43 100644
--- a/backend/dll.c
+++ b/backend/dll.c
@@ -89,6 +89,19 @@ posix_dlsym (void *handle, const char *func)
 }
 # pragma GCC diagnostic pop
 
+  /* Similar to the above, GCC also warns about conversion between
+     pointers to functions.  The ISO C standard says that invoking a
+     converted pointer to a function whose type is not compatible with
+     the pointed-to type, the behavior is undefined.  Although GCC is
+     correct to warn about this, the dll backend has been using these
+     conversions without issues for a very long time already.
+
+     Rather than push/pop around every use, which would get very ugly
+     real fast, ignore this particular warning for the remainder of
+     the file.
+   */
+# pragma GCC diagnostic ignored "-Wcast-function-type"
+
   /* Older versions of dlopen() don't define RTLD_NOW and RTLD_LAZY.
      They all seem to use a mode of 1 to indicate RTLD_NOW and some do
      not support RTLD_LAZY at all.  Hence, unless defined, we define

From fd407cc58bce4162a8329fb4ec587837f50c1fd0 Mon Sep 17 00:00:00 2001
From: Olaf Meeuwissen <paddy-hack@member.fsf.org>
Date: Sun, 22 Dec 2019 18:34:45 +0900
Subject: [PATCH 3/3] dll: Make previous change backwardly compatible

Older GCC do not know the cast-function-pragma and flag that as a
warning.  That results in an error on our Debian 9 build.
---
 backend/dll.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/backend/dll.c b/backend/dll.c
index 39531bd43..73ffde41c 100644
--- a/backend/dll.c
+++ b/backend/dll.c
@@ -100,6 +100,7 @@ posix_dlsym (void *handle, const char *func)
      real fast, ignore this particular warning for the remainder of
      the file.
    */
+# pragma GCC diagnostic ignored "-Wpragmas" /* backward compatibility */
 # pragma GCC diagnostic ignored "-Wcast-function-type"
 
   /* Older versions of dlopen() don't define RTLD_NOW and RTLD_LAZY.