Fix review findings

- Switch to `default` as defined by triage
- Use a more vague wording in documentation to indicate that the implementation can evolve in the future
- Fix the at least misleading if not incorrect wording in NEWS.

Co-authored-by: Copilot <copilot@github.com>

Author: Patrick Häcker

NEWS.md

@@ -41,9 +41,10 @@ Command-line option changes
 ---------------------------
 
   - `-P <project>` is now a shorthand for `--project <project>` ([#59867]).
-  - The `--warn-overwrite` option now accepts the new default `auto` in addition to `yes`
-    and `no`. In this mode, warnings are shown only when a method is overwritten by a
-    different module, which is the case that errors during precompilation ([#61388]).
+  - The `--warn-overwrite` option gains a new value `default` (now the default), in addition
+    to `yes` and `no`. Under `default`, warnings are emitted only for cross-module method
+    overwrites — typically unintentional cases such as method piracy or package conflicts
+    ([#61388]).
 
 Multi-threading changes
 -----------------------

doc/man/julia.1

@@ -171,8 +171,8 @@ Load or save history
 Enable or disable syntax and method deprecation warnings (`error` turns warnings into errors)
 
 .TP
---warn-overwrite={yes|no|auto*}
-Enable or disable method overwrite warnings (`auto` warns for cross-module overwrites only)
+--warn-overwrite={yes|no|default*}
+Enable or disable method overwrite warnings (`default` warns for likely-unintentional overwrites, currently: cross-module overwrites)
 
 .TP
 --warn-scope={yes*|no}

doc/src/manual/command-line-interface.md

@@ -197,7 +197,7 @@ The following is a complete list of command-line switches available when launchi
 |`--color={yes\|no\|auto*}`             |Enable or disable color text|
 |`--history-file={yes*\|no}`            |Load or save history|
 |`--depwarn={yes\|no*\|error}`          |Enable or disable syntax and method deprecation warnings (`error` turns warnings into errors)|
-|`--warn-overwrite={yes\|no\|auto*}`    |Enable or disable method overwrite warnings (`auto` warns for cross-module overwrites only)|
+|`--warn-overwrite={yes\|no\|default*}` |Enable or disable method overwrite warnings (`default` warns for likely-unintentional overwrites, currently: cross-module overwrites)|
 |`--warn-scope={yes*\|no}`              |Enable or disable warning for ambiguous top-level scope|
 |`-C`, `--cpu-target <target>`          |Limit usage of CPU features up to `<target>`; set to `help` to see the available options|
 |`-O`, `--optimize={0\|1\|2*\|3}`       |Set the optimization level (level is 3 if `-O` is used without a level) ($)|

src/gf.c

@@ -2059,7 +2059,7 @@ static void method_overwrite(jl_typemap_entry_t *newentry, jl_method_t *oldvalue
         dt = jl_nth_argument_datatype(oldvalue->sig, 3);
     int anon = dt && is_anonfn_typename(jl_symbol_name(dt->name->name));
     if ((jl_options.warn_overwrite == JL_OPTIONS_WARN_OVERWRITE_ON) ||
-        (jl_options.warn_overwrite == JL_OPTIONS_WARN_OVERWRITE_AUTO && oldmod != newmod) ||
+        (jl_options.warn_overwrite == JL_OPTIONS_WARN_OVERWRITE_DEFAULT && oldmod != newmod) ||
         (jl_options.incremental && jl_generating_output()) || anon) {
         JL_STREAM *s = JL_STDERR;
         jl_printf(s, "WARNING: Method definition ");

src/jloptions.c

@@ -124,7 +124,7 @@ JL_DLLEXPORT void jl_init_options(void)
 #endif
                         JL_OPTIONS_CHECK_BOUNDS_DEFAULT, // check_bounds
                         JL_OPTIONS_DEPWARN_OFF,    // deprecation warning
-                        JL_OPTIONS_WARN_OVERWRITE_AUTO, // method overwrite warning
+                        JL_OPTIONS_WARN_OVERWRITE_DEFAULT, // method overwrite warning
                         1,    // can_inline
                         JL_OPTIONS_POLLY_ON, // polly
                         NULL, // trace_compile
@@ -245,8 +245,9 @@ static const char opts[]  =
     // error and warning options
     " --depwarn={yes|no*|error}                     Enable or disable syntax and method deprecation\n"
     "                                               warnings (`error` turns warnings into errors)\n"
-    " --warn-overwrite={yes|no|auto*}               Enable or disable method overwrite warnings\n"
-    "                                               (`auto` warns for cross-module overwrites only)\n"
+    " --warn-overwrite={yes|no|default*}            Enable or disable method overwrite warnings\n"
+    "                                               (`default` warns for likely-unintentional overwrites,\n"
+    "                                               currently: cross-module overwrites)\n"
     " --warn-scope={yes*|no}                        Enable or disable warning for ambiguous top-level\n"
     "                                               scope\n\n"
 
@@ -929,10 +930,10 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
                 jl_options.warn_overwrite = JL_OPTIONS_WARN_OVERWRITE_ON;
             else if (!strcmp(optarg,"no"))
                 jl_options.warn_overwrite = JL_OPTIONS_WARN_OVERWRITE_OFF;
-            else if (!strcmp(optarg,"auto"))
-                jl_options.warn_overwrite = JL_OPTIONS_WARN_OVERWRITE_AUTO;
+            else if (!strcmp(optarg,"default"))
+                jl_options.warn_overwrite = JL_OPTIONS_WARN_OVERWRITE_DEFAULT;
             else
-                jl_errorf("julia: invalid argument to --warn-overwrite={yes|no|auto} (%s)", optarg);
+                jl_errorf("julia: invalid argument to --warn-overwrite={yes|no|default} (%s)", optarg);
             break;
         case opt_warn_scope:
             if (!strcmp(optarg,"yes"))

src/julia.h

@@ -2615,7 +2615,7 @@ JL_DLLEXPORT int jl_generating_output(void) JL_NOTSAFEPOINT;
 
 #define JL_OPTIONS_WARN_OVERWRITE_OFF 0
 #define JL_OPTIONS_WARN_OVERWRITE_ON 1
-#define JL_OPTIONS_WARN_OVERWRITE_AUTO 2
+#define JL_OPTIONS_WARN_OVERWRITE_DEFAULT 2
 
 #define JL_OPTIONS_WARN_SCOPE_OFF 0
 #define JL_OPTIONS_WARN_SCOPE_ON 1

test/misc.jl

@@ -99,14 +99,14 @@ let
         WARNING: Method definition f() in module Main at none:2 overwritten at none:3.
         WARNING: Method definition g() in module Main at none:4 overwritten on the same line.
         """
-    # default (auto): warn on cross-module overwrites and anonymous functions
+    # default: warn on cross-module overwrites and anonymous functions
     warning_str = read(`$exename --startup-file=no -e $script`, String)
     @test warning_str == """
         WARNING: Method definition f() in module A at none:2 overwritten in module Main on the same line (check for duplicate calls to `include`).
         WARNING: Method definition g() in module Main at none:4 overwritten on the same line.
         """
-    # --warn-overwrite=auto: same as default
-    warning_str = read(`$exename --warn-overwrite=auto --startup-file=no -e $script`, String)
+    # --warn-overwrite=default: same as default
+    warning_str = read(`$exename --warn-overwrite=default --startup-file=no -e $script`, String)
     @test warning_str == """
         WARNING: Method definition f() in module A at none:2 overwritten in module Main on the same line (check for duplicate calls to `include`).
         WARNING: Method definition g() in module Main at none:4 overwritten on the same line.
@@ -116,15 +116,15 @@ let
     @test warning_str == """
         WARNING: Method definition g() in module Main at none:4 overwritten on the same line.
         """
-    # same-module overwrite: no warning with auto
+    # same-module overwrite: no warning with default
     same_mod_script = """
         $redir_err
         f(x) = 5*x
         f(x) = 2*x
         """
     warning_str = read(`$exename --startup-file=no -e $same_mod_script`, String)
     @test warning_str == ""
-    # cross-module overwrite: warning with auto
+    # cross-module overwrite: warning with default
     cross_mod_script = """
         $redir_err
         module B; h(x) = 1; end