[ruby/prism] Add error for numbered parameter used in inner block

https://github.com/ruby/prism/commit/c386ba6d48

5 files changed, 38 insertions, 10 deletions

diff --git a/prism/config.yml b/prism/config.yml
index 6b4b1aa9c0..cfcfd2e7aa 100644
--- a/prism/config.yml
+++ b/prism/config.yml
@@ -114,6 +114,7 @@ errors:
   - EXPRESSION_NOT_WRITABLE_FILE
   - EXPRESSION_NOT_WRITABLE_LINE
   - EXPRESSION_NOT_WRITABLE_NIL
+  - EXPRESSION_NOT_WRITABLE_NUMBERED
   - EXPRESSION_NOT_WRITABLE_SELF
   - EXPRESSION_NOT_WRITABLE_TRUE
   - FLOAT_PARSE
@@ -185,9 +186,10 @@ errors:
   - NO_LOCAL_VARIABLE
   - NOT_EXPRESSION
   - NUMBER_LITERAL_UNDERSCORE
+  - NUMBERED_PARAMETER_INNER_BLOCK
   - NUMBERED_PARAMETER_IT
   - NUMBERED_PARAMETER_ORDINARY
-  - NUMBERED_PARAMETER_OUTER_SCOPE
+  - NUMBERED_PARAMETER_OUTER_BLOCK
   - OPERATOR_MULTI_ASSIGN
   - OPERATOR_WRITE_ARGUMENTS
   - OPERATOR_WRITE_BLOCK
diff --git a/prism/parser.h b/prism/parser.h
index 8054e332f7..ff1261841c 100644
--- a/prism/parser.h
+++ b/prism/parser.h
@@ -609,6 +609,7 @@ static const uint8_t PM_SCOPE_PARAMETERS_FORWARDING_KEYWORDS = 0x10;
 static const uint8_t PM_SCOPE_PARAMETERS_FORWARDING_BLOCK = 0x20;
 static const uint8_t PM_SCOPE_PARAMETERS_FORWARDING_ALL = 0x40;
 
+static const int8_t PM_SCOPE_NUMBERED_PARAMETERS_INNER = -2;
 static const int8_t PM_SCOPE_NUMBERED_PARAMETERS_DISALLOWED = -1;
 static const int8_t PM_SCOPE_NUMBERED_PARAMETERS_NONE = 0;
 
diff --git a/prism/prism.c b/prism/prism.c
index cf8ce7c830..e146799393 100644
--- a/prism/prism.c
+++ b/prism/prism.c
@@ -13365,14 +13365,20 @@ parse_write(pm_parser_t *parser, pm_node_t *target, pm_token_t *operator, pm_nod
             return (pm_node_t *) node;
         }
         case PM_LOCAL_VARIABLE_READ_NODE: {
-            pm_refute_numbered_parameter(parser, target->location.start, target->location.end);
             pm_local_variable_read_node_t *local_read = (pm_local_variable_read_node_t *) target;
 
             pm_constant_id_t name = local_read->name;
+            pm_location_t name_loc = target->location;
+
             uint32_t depth = local_read->depth;
-            pm_locals_unread(&pm_parser_scope_find(parser, depth)->locals, name);
+            pm_scope_t *scope = pm_parser_scope_find(parser, depth);
 
-            pm_location_t name_loc = target->location;
+            if (pm_token_is_numbered_parameter(target->location.start, target->location.end)) {
+                pm_diagnostic_id_t diag_id = scope->parameters > PM_SCOPE_NUMBERED_PARAMETERS_NONE ? PM_ERR_EXPRESSION_NOT_WRITABLE_NUMBERED : PM_ERR_PARAMETER_NUMBERED_RESERVED;
+                PM_PARSER_ERR_FORMAT(parser, target->location.start, target->location.end, diag_id, target->location.start);
+            }
+
+            pm_locals_unread(&scope->locals, name);
             pm_node_destroy(parser, target);
 
             return (pm_node_t *) pm_local_variable_write_node_create(parser, name, depth, value, &name_loc, operator);
@@ -15829,17 +15835,34 @@ parse_variable(pm_parser_t *parser) {
         } else if (current_scope->parameters & PM_SCOPE_PARAMETERS_IT) {
             pm_parser_err_previous(parser, PM_ERR_NUMBERED_PARAMETER_IT);
         } else if (outer_scope_using_numbered_parameters_p(parser)) {
-            pm_parser_err_previous(parser, PM_ERR_NUMBERED_PARAMETER_OUTER_SCOPE);
+            pm_parser_err_previous(parser, PM_ERR_NUMBERED_PARAMETER_OUTER_BLOCK);
+        } else if (current_scope->numbered_parameters == PM_SCOPE_NUMBERED_PARAMETERS_INNER) {
+            pm_parser_err_previous(parser, PM_ERR_NUMBERED_PARAMETER_INNER_BLOCK);
         } else {
             // Indicate that this scope is using numbered params so that child
             // scopes cannot. We subtract the value for the character '0' to get
             // the actual integer value of the number (only _1 through _9 are
             // valid).
             int8_t numbered_parameters = (int8_t) (parser->previous.start[1] - '0');
-            current_scope->parameters |= PM_SCOPE_PARAMETERS_NUMBERED;
 
-            if (numbered_parameters > current_scope->numbered_parameters) {
-                current_scope->numbered_parameters = numbered_parameters;
+            // If we're about to match an =, then this is an invalid use of
+            // numbered parameters. We'll create all of the necessary
+            // infrastructure around it, but not actually mark the scope as
+            // using numbered parameters so that we can get the right error
+            // message.
+            if (!match1(parser, PM_TOKEN_EQUAL)) {
+                current_scope->parameters |= PM_SCOPE_PARAMETERS_NUMBERED;
+
+                if (numbered_parameters > current_scope->numbered_parameters) {
+                    current_scope->numbered_parameters = numbered_parameters;
+                }
+
+                // Go through the parent scopes and mark them as being
+                // disallowed from using numbered parameters because this inner
+                // scope is using them.
+                for (pm_scope_t *scope = current_scope->previous; scope != NULL && !scope->closed; scope = scope->previous) {
+                    scope->numbered_parameters = PM_SCOPE_NUMBERED_PARAMETERS_INNER;
+                }
             }
 
             // When you use a numbered parameter, it implies the existence
diff --git a/prism/templates/src/diagnostic.c.erb b/prism/templates/src/diagnostic.c.erb
index 57c52602f4..30d6b0ffed 100644
--- a/prism/templates/src/diagnostic.c.erb
+++ b/prism/templates/src/diagnostic.c.erb
@@ -197,6 +197,7 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = {
     [PM_ERR_EXPRESSION_NOT_WRITABLE_FILE]       = { "Can't assign to __FILE__", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPRESSION_NOT_WRITABLE_LINE]       = { "Can't assign to __LINE__", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPRESSION_NOT_WRITABLE_NIL]        = { "Can't assign to nil", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_EXPRESSION_NOT_WRITABLE_NUMBERED]   = { "Can't assign to numbered parameter %.2s", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPRESSION_NOT_WRITABLE_SELF]       = { "Can't change the value of self", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPRESSION_NOT_WRITABLE_TRUE]       = { "Can't assign to true", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_FLOAT_PARSE]                        = { "could not parse the float '%.*s'", PM_ERROR_LEVEL_SYNTAX },
@@ -267,9 +268,10 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = {
     [PM_ERR_NOT_EXPRESSION]                     = { "expected an expression after `not`", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_NO_LOCAL_VARIABLE]                  = { "%.*s: no such local variable", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_NUMBER_LITERAL_UNDERSCORE]          = { "number literal ending with a `_`", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_NUMBERED_PARAMETER_INNER_BLOCK]     = { "numbered parameter is already used in inner block", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_NUMBERED_PARAMETER_IT]              = { "numbered parameters are not allowed when an 'it' parameter is defined", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_NUMBERED_PARAMETER_ORDINARY]        = { "numbered parameters are not allowed when an ordinary parameter is defined", PM_ERROR_LEVEL_SYNTAX },
-    [PM_ERR_NUMBERED_PARAMETER_OUTER_SCOPE]     = { "numbered parameter is already used in outer scope", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_NUMBERED_PARAMETER_OUTER_BLOCK]     = { "numbered parameter is already used in outer block", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_OPERATOR_MULTI_ASSIGN]              = { "unexpected operator for a multiple assignment", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_OPERATOR_WRITE_ARGUMENTS]           = { "unexpected operator after a call with arguments", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_OPERATOR_WRITE_BLOCK]               = { "unexpected operator after a call with a block", PM_ERROR_LEVEL_SYNTAX },
diff --git a/test/prism/errors_test.rb b/test/prism/errors_test.rb
index 3670b90dd7..6f926452fa 100644
--- a/test/prism/errors_test.rb
+++ b/test/prism/errors_test.rb
@@ -1377,7 +1377,7 @@ module Prism
 
     def test_double_scope_numbered_parameters
       source = "-> { _1 + -> { _2 } }"
-      errors = [["numbered parameter is already used in outer scope", 15..17]]
+      errors = [["numbered parameter is already used in outer block", 15..17]]
 
       assert_errors expression(source), source, errors
     end