make-4.4.1-warn-noargs.patch

--- make-4.4.1-orig/src/main.c	2023-02-21 08:03:51.000000000 +0300
+++ make-4.4.1/src/main.c	2024-09-18 08:53:02.804603700 +0300
@@ -286,6 +286,8 @@
 
 int warn_undefined_variables_flag;
 
+static char *warn_undefined_variables_option = 0;
+
 /* If nonzero, always build all targets, regardless of whether
    they appear out of date or not.  */
 
@@ -402,7 +404,8 @@
   -W FILE, --what-if=FILE, --new-file=FILE, --assume-new=FILE\n\
                               Consider FILE to be infinitely new.\n"),
     N_("\
-  --warn-undefined-variables  Warn when an undefined variable is referenced.\n"),
+  --warn-undefined-variables[=TYPE]\n\
+                              Warn when an undefined variable is referenced.\n"),
     NULL
   };
 
@@ -497,7 +500,7 @@
     { CHAR_MAX+3, flag, &trace_flag, 1, 1, 0, 0, 0, 0, "trace", 0 },
     { CHAR_MAX+4, flag_off, &print_directory_flag, 1, 1, 0, 0, 0,
       &default_print_directory_flag, "no-print-directory", &print_directory_origin },
-    { CHAR_MAX+5, flag, &warn_undefined_variables_flag, 1, 1, 0, 0, 0, 0,
+    { CHAR_MAX+5, string, &warn_undefined_variables_option, 1, 1, 0, 0, "noargs", 0,
       "warn-undefined-variables", 0 },
     { CHAR_MAX+7, string, &sync_mutex, 1, 1, 0, 0, 0, 0, "sync-mutex", 0 },
     { CHAR_MAX+8, flag_off, &silent_flag, 1, 1, 0, 0, 0, &default_silent_flag,
@@ -925,6 +928,24 @@
   die (bad ? MAKE_FAILURE : MAKE_SUCCESS);
 }
 
+static void
+decode_warn_undefined_flags (void)
+{
+  if (warn_undefined_variables_option)
+    {
+      if (streq (warn_undefined_variables_option, "all"))
+        warn_undefined_variables_flag = WARN_UNDEFINED_BASE | WARN_UNDEFINED_ARGS;
+      else if (streq (warn_undefined_variables_option, "noargs"))
+        warn_undefined_variables_flag = WARN_UNDEFINED_BASE;
+      else if (streq (warn_undefined_variables_option, "args"))
+        warn_undefined_variables_flag = WARN_UNDEFINED_ARGS;
+      else
+        OS (fatal, NILF,
+            _("unknown warn-undefined-variables type '%s'"),
+            warn_undefined_variables_option);
+    }
+}
+
 #ifdef WINDOWS32
 
 /*
@@ -3373,6 +3394,7 @@
   /* If there are any options that need to be decoded do it now.  */
   decode_debug_flags ();
   decode_output_sync_flags ();
+  decode_warn_undefined_flags ();
 
   /* Perform any special switch handling.  */
   run_silent = silent_flag;
--- make-4.4.1-orig/src/variable.c	2023-01-28 21:04:47.000000000 +0300
+++ make-4.4.1/src/variable.c	2024-09-18 09:04:48.464092600 +0300
@@ -1855,6 +1855,25 @@
   return vp;
 }
 
+static int
+filter_undefined_variable_warn (const char *name, size_t length)
+{
+  if (!(warn_undefined_variables_flag & WARN_UNDEFINED_BASE) ||
+      !(warn_undefined_variables_flag & WARN_UNDEFINED_ARGS))
+    {
+      /* $(call ...) arguments are named as $1,$2,$3 and so on,
+         check if variable name is numeric.  */
+      size_t i;
+      for (i = 0; i < length && ISDIGIT(name[i]); ++i);
+
+      if ((i == length && !(warn_undefined_variables_flag & WARN_UNDEFINED_ARGS)) ||
+          (i != length && !(warn_undefined_variables_flag & WARN_UNDEFINED_BASE)))
+          return 1;
+    }
+
+  return 0;
+}
+
 /* These variables are internal to make, and so considered "defined" for the
    purposes of warn_undefined even if they are not really defined.  */
 
@@ -1888,6 +1907,9 @@
         if (dp->len == len && memcmp (dp->name, name, len) == 0)
           return;
 
+      if (filter_undefined_variable_warn (name, len))
+        return;
+
       error (reading_file, len, _("warning: undefined variable '%.*s'"),
              (int)len, name);
     }
--- make-4.4.1-orig/src/variable.h	2023-01-28 21:04:47.000000000 +0300
+++ make-4.4.1/src/variable.h	2024-09-18 08:57:33.459838100 +0300
@@ -207,6 +207,9 @@
                                          const floc *flocp);
 void warn_undefined (const char* name, size_t length);
 
+#define WARN_UNDEFINED_BASE  (0x001)
+#define WARN_UNDEFINED_ARGS  (0x002)
+
 /* Define a variable in the current variable set.  */
 
 #define define_variable(n,l,v,o,r) \