fix(warnings): annotate or ignore all uses of printf formatting

This fixes all clang 22 warnings of the form: "warning: diagnostic behavior
may be improved by adding the 'format(printf, 3, 4)' attribute to the
declaration of 'some_function'"

dialog_msg() was essentially a NULL-handling wrapper. but some callsites
already use their own NULL handling or NULL:s are impossible as the
value has already been assumed non-NULL. Non-locally assuming
a buffer size is also a code smell, especially if we can
just use "sizeof buff" without a wrapper.

append_redir() is... whatever it is.

src/nvim/ex_cmds.c

@@ -1662,7 +1662,13 @@ void append_redir(char *const buf, const size_t buflen, const char *const opt,
   }
   if (p != NULL) {
     *end = ' ';  // not really needed? Not with sh, ksh or bash
+
+// This looks incredibly suss because it is: we are allowing a user option to
+// define a snprintf format string. Such code should normally not be written.
+// The validitiy of these option values are checked in `did_set_shellpipe_redir`
+    PRAGMA_DIAG_PUSH_IGNORE_MISSING_FORMAT_ATTRIBUTE;
     vim_snprintf(end + 1, (size_t)((ptrdiff_t)buflen - (end + 1 - buf)), opt, fname);
+    PRAGMA_DIAG_POP;
   } else {
     vim_snprintf(end, (size_t)((ptrdiff_t)buflen - (end - buf)), " %s %s", opt, fname);
   }
@@ -2023,8 +2029,7 @@ int check_overwrite(exarg_T *eap, buf_T *buf, char *fname, char *ffname, bool ot
 #endif
       if (p_confirm || (cmdmod.cmod_flags & CMOD_CONFIRM)) {
         char buff[DIALOG_MSG_SIZE];
-
-        dialog_msg(buff, _("Overwrite existing file \"%s\"?"), fname);
+        snprintf(buff, sizeof buff, _("Overwrite existing file \"%s\"?"), fname);
         if (vim_dialog_yesno(VIM_QUESTION, NULL, buff, 2) != VIM_YES) {
           return FAIL;
         }
@@ -2058,9 +2063,9 @@ int check_overwrite(exarg_T *eap, buf_T *buf, char *fname, char *ffname, bool ot
         if (p_confirm || (cmdmod.cmod_flags & CMOD_CONFIRM)) {
           char buff[DIALOG_MSG_SIZE];
 
-          dialog_msg(buff,
-                     _("Swap file \"%s\" exists, overwrite anyway?"),
-                     swapname);
+          vim_snprintf(buff, sizeof buff,
+                       _("Swap file \"%s\" exists, overwrite anyway?"),
+                       swapname);
           if (vim_dialog_yesno(VIM_QUESTION, NULL, buff, 2)
               != VIM_YES) {
             xfree(swapname);
@@ -2184,15 +2189,16 @@ static int check_readonly(int *forceit, buf_T *buf)
     if ((p_confirm || (cmdmod.cmod_flags & CMOD_CONFIRM)) && buf->b_fname != NULL) {
       char buff[DIALOG_MSG_SIZE];
 
+      const char *fname = buf->b_fname ? buf->b_fname : _("Untitled");
       if (buf->b_p_ro) {
-        dialog_msg(buff,
-                   _("'readonly' option is set for \"%s\".\nDo you wish to write anyway?"),
-                   buf->b_fname);
+        snprintf(buff, sizeof buff,
+                 _("'readonly' option is set for \"%s\".\nDo you wish to write anyway?"),
+                 fname);
       } else {
-        dialog_msg(buff,
-                   _("File permissions of \"%s\" are read-only.\nIt may still be possible to "
-                     "write it.\nDo you wish to try?"),
-                   buf->b_fname);
+        snprintf(buff, sizeof buff,
+                 _("File permissions of \"%s\" are read-only.\nIt may still be possible to "
+                   "write it.\nDo you wish to try?"),
+                 fname);
       }
 
       if (vim_dialog_yesno(VIM_QUESTION, NULL, buff, 2) == VIM_YES) {

src/nvim/ex_cmds2.c

@@ -203,7 +203,8 @@ void dialog_changed(buf_T *buf, bool checkall)
     .forceit = false,
   };
 
-  dialog_msg(buff, _("Save changes to \"%s\"?"), buf->b_fname);
+  const char *fname = buf->b_fname ? buf->b_fname : _("Untitled");
+  snprintf(buff, sizeof buff, _("Save changes to \"%s\"?"), fname);
   if (checkall) {
     ret = vim_dialog_yesnoallcancel(VIM_QUESTION, NULL, buff, 1);
   } else {
@@ -267,8 +268,8 @@ bool dialog_close_terminal(buf_T *buf)
 {
   char buff[DIALOG_MSG_SIZE];
 
-  dialog_msg(buff, _("Close \"%s\"?"),
-             (buf->b_fname != NULL) ? buf->b_fname : "?");
+  snprintf(buff, sizeof buff, _("Close \"%s\"?"),
+           (buf->b_fname != NULL) ? buf->b_fname : "?");
 
   int ret = vim_dialog_yesnocancel(VIM_QUESTION, NULL, buff, 1);
 

src/nvim/ex_docmd.c

@@ -8041,16 +8041,6 @@ static void ex_shada(exarg_T *eap)
   p_shada = save_shada;
 }
 
-/// Make a dialog message in "buff[DIALOG_MSG_SIZE]".
-/// "format" must contain "%s".
-void dialog_msg(char *buff, char *format, char *fname)
-{
-  if (fname == NULL) {
-    fname = _("Untitled");
-  }
-  vim_snprintf(buff, DIALOG_MSG_SIZE, format, fname);
-}
-
 static TriState filetype_detect = kNone;
 static TriState filetype_plugin = kNone;
 static TriState filetype_indent = kNone;

src/nvim/ex_docmd.h

@@ -28,7 +28,7 @@ enum {
 // Whether a command index indicates a user command.
 #define IS_USER_CMDIDX(idx) ((int)(idx) < 0)
 
-enum { DIALOG_MSG_SIZE = 1000, };  ///< buffer size for dialog_msg()
+enum { DIALOG_MSG_SIZE = 1000, };  ///< buffer size for dialog messages
 
 /// Structure used to save the current state.  Used when executing Normal mode
 /// commands while in any other mode.

src/nvim/macros_defs.h

@@ -145,6 +145,9 @@
 # define PRAGMA_DIAG_PUSH_IGNORE_MISSING_PROTOTYPES \
   _Pragma("clang diagnostic push") \
   _Pragma("clang diagnostic ignored \"-Wmissing-prototypes\"")
+# define PRAGMA_DIAG_PUSH_IGNORE_MISSING_FORMAT_ATTRIBUTE \
+  _Pragma("clang diagnostic push") \
+  _Pragma("clang diagnostic ignored \"-Wmissing-format-attribute\"")
 # ifdef HAVE_WIMPLICIT_FALLTHROUGH_FLAG
 #  define PRAGMA_DIAG_PUSH_IGNORE_IMPLICIT_FALLTHROUGH \
   _Pragma("clang diagnostic push") \
@@ -159,6 +162,8 @@
 # define PRAGMA_DIAG_PUSH_IGNORE_MISSING_PROTOTYPES \
   _Pragma("GCC diagnostic push") \
   _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
+# define PRAGMA_DIAG_PUSH_IGNORE_MISSING_FORMAT_ATTRIBUTE \
+  _Pragma("GCC diagnostic push")
 # ifdef HAVE_WIMPLICIT_FALLTHROUGH_FLAG
 #  define PRAGMA_DIAG_PUSH_IGNORE_IMPLICIT_FALLTHROUGH \
   _Pragma("GCC diagnostic push") \
@@ -171,6 +176,7 @@
   _Pragma("GCC diagnostic pop")
 #else
 # define PRAGMA_DIAG_PUSH_IGNORE_MISSING_PROTOTYPES
+# define PRAGMA_DIAG_PUSH_IGNORE_MISSING_FORMAT_ATTRIBUTE
 # define PRAGMA_DIAG_PUSH_IGNORE_IMPLICIT_FALLTHROUGH
 # define PRAGMA_DIAG_POP
 #endif

src/nvim/optionstr.c

@@ -2306,12 +2306,15 @@ static const struct chars_tab lcs_tab[] = {
 
 #undef CHARSTAB_ENTRY
 
-static char *field_value_err(char *errbuf, size_t errbuflen, const char *fmt, const char *field)
+static char *field_value_err(char *errbuf, size_t errbuflen, const char *fmt, ...)
 {
   if (errbuf == NULL) {
     return "";
   }
-  vim_snprintf(errbuf, errbuflen, _(fmt), field);
+  va_list arglist;
+  va_start(arglist, fmt);
+  vim_vsnprintf(errbuf, errbuflen, _(fmt), arglist);
+  va_end(arglist);
   return errbuf;
 }