add --warn-scope command line option

NEWS.md

@@ -18,7 +18,8 @@ Language changes
 * Outside of the REPL (e.g. in a file), assigning to a variable within a top-level scope
  block is considered ambiguous if a global variable with the same name exists.
  A warning is given if that happens, to alert you that the code will work differently
- than in the REPL ([#33864]).
+ than in the REPL.
+ A new command line option `--warn-scope` controls this warning ([#33864]).
 
 * Converting arbitrary tuples to `NTuple`, e.g. `convert(NTuple, (1, ""))` now gives an error,
  where it used to be incorrectly allowed. This is because `NTuple` refers only to homogeneous

base/options.jl

@@ -41,6 +41,7 @@ struct JLOptions
  outputji::Ptr{UInt8}
  output_code_coverage::Ptr{UInt8}
  incremental::Int8
+ warn_scope::Int8
 end
 
 # This runs early in the sysimage != is not defined yet

src/ast.c

@@ -251,6 +251,7 @@ static void jl_init_ast_ctx(jl_ast_context_t *ast_ctx) JL_NOTSAFEPOINT
  ctx->task = NULL;
  ctx->module = NULL;
  set(symbol(fl_ctx, "*depwarn-opt*"), fixnum(jl_options.depwarn));
+ set(symbol(fl_ctx, "*scopewarn-opt*"), fixnum(jl_options.warn_scope));
 }
 
 // There should be no GC allocation while holding this lock

src/jlfrontend.scm

@@ -242,6 +242,8 @@
  (if (equal? instead "") ""
  (string #\newline "Use `" instead "` instead."))))
 
+(define *scopewarn-opt* 1)
+
 ; Corresponds to --depwarn 0="no", 1="yes", 2="error"
 (define *depwarn-opt* 1)
 

src/jloptions.c

@@ -71,7 +71,8 @@ jl_options_t jl_options = { 0, // quiet
  NULL, // output-ji
  NULL, // output-code_coverage
  0, // incremental
- 0 // image_file_specified
+ 0, // image_file_specified
+ JL_OPTIONS_WARN_SCOPE_ON // ambiguous scope warning
 };
 
 static const char usage[] = "julia [switches] -- [programfile] [args...]\n";
@@ -109,7 +110,8 @@ static const char opts[] =
 
  // error and warning options
  " --depwarn={yes|no|error} Enable or disable syntax and method deprecation warnings (\"error\" turns warnings into errors)\n"
- " --warn-overwrite={yes|no} Enable or disable method overwrite warnings\n\n"
+ " --warn-overwrite={yes|no} Enable or disable method overwrite warnings\n"
+ " --warn-scope={yes|no} Enable or disable warning for ambiguous top-level scope\n\n"
 
  // code generation options
  " -C, --cpu-target <target> Limit usage of CPU features up to <target>; set to \"help\" to see the available options\n"
@@ -169,6 +171,7 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
  opt_output_bc,
  opt_depwarn,
  opt_warn_overwrite,
+ opt_warn_scope,
  opt_inline,
  opt_polly,
  opt_trace_compile,
@@ -225,6 +228,7 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
  { "output-incremental",required_argument, 0, opt_incremental },
  { "depwarn", required_argument, 0, opt_depwarn },
  { "warn-overwrite", required_argument, 0, opt_warn_overwrite },
+ { "warn-scope", required_argument, 0, opt_warn_scope },
  { "inline", required_argument, 0, opt_inline },
  { "polly", required_argument, 0, opt_polly },
  { "trace-compile", required_argument, 0, opt_trace_compile },
@@ -554,7 +558,15 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
  else if (!strcmp(optarg,"no"))
  jl_options.warn_overwrite = JL_OPTIONS_WARN_OVERWRITE_OFF;
  else
- jl_errorf("julia: invalid argument to --warn-overwrite={yes|no|} (%s)", optarg);
+ jl_errorf("julia: invalid argument to --warn-overwrite={yes|no} (%s)", optarg);
+ break;
+ case opt_warn_scope:
+ if (!strcmp(optarg,"yes"))
+ jl_options.warn_scope = JL_OPTIONS_WARN_SCOPE_ON;
+ else if (!strcmp(optarg,"no"))
+ jl_options.warn_scope = JL_OPTIONS_WARN_SCOPE_OFF;
+ else
+ jl_errorf("julia: invalid argument to --warn-scope={yes|no} (%s)", optarg);
  break;
  case opt_inline:
  if (!strcmp(optarg,"yes"))

src/julia-syntax.scm

@@ -2674,7 +2674,8 @@
  (else
  (if (and (eq? (car e) '=) (symbol? (cadr e))
  scope (null? (lam:vars (scope:lam scope)))
- (warn-var?! (cadr e) scope))
+ (warn-var?! (cadr e) scope)
+ (= *scopewarn-opt* 1))
  (let* ((v (cadr e))
  (loc (extract-line-file loc))
  (line (if (= (car loc) 0) (julia-current-line) (car loc)))

src/julia.h

@@ -1936,6 +1936,7 @@ typedef struct {
  const char *output_code_coverage;
  int8_t incremental;
  int8_t image_file_specified;
+ int8_t warn_scope;
 } jl_options_t;
 
 extern JL_DLLEXPORT jl_options_t jl_options;
@@ -1992,6 +1993,9 @@ 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_SCOPE_OFF 0
+#define JL_OPTIONS_WARN_SCOPE_ON 1
+
 #define JL_OPTIONS_POLLY_ON 1
 #define JL_OPTIONS_POLLY_OFF 0