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Factor block variable declaration grammar 

Block variable declarations currently combine optional `const` and lifetime
qualifiers with the data type. This requires reducing empty qualifier rules
before the parser can determine which declaration form follows, making the
rule difficult to use in a mixed procedural item list without conflicts.

Split the declaration productions according to their leading syntax. Share
required and optional variable lifetime handling and add a rule for data types
following the historical leading `reg` extension. This keeps the declaration
behavior unchanged while allowing the parser to distinguish each form from
its leading token.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
This commit is contained in:
Lars-Peter Clausen 2026-07-18 15:47:30 -07:00
parent 7792b5ab8a
commit 97928cfb15
1 changed files with 63 additions and 6 deletions
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69
parse.y
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@ -947,6 +947,7 @@ Module::port_t *module_declare_interface_port(const YYLTYPE&loc, char *type,
%type <decl_assignments_with_type> list_of_variable_decl_assignments_with_type
%type <data_type> data_type data_type_opt data_type_or_implicit data_type_or_implicit_or_void
%type <data_type> block_reg_data_type
%type <data_type> implicit_type
%type <data_type> reg_prefixed_atomic_type simple_type_or_string let_formal_type
%type <data_type> packed_array_data_type atomic_type
@ -1569,6 +1570,17 @@ atomic_type
}
;
block_reg_data_type
: unsigned_signed_opt dimensions_opt
{ vector_type_t *tmp = new vector_type_t(IVL_VT_LOGIC, $1, $2);
FILE_NAME(tmp, @1);
$$ = tmp;
}
| reg_prefixed_atomic_type
{ $$ = $1;
}
;
/* Data types allowed after the historical iverilog extension that permits an
extra leading `reg` in block declarations. Keep `reg` itself out of this
subset so ordinary `reg` declarations continue through the normal rules. */
@ -3056,7 +3068,7 @@ variable_dimension /* IEEE1800-2005: A.2.5 */
}
;
variable_lifetime_opt
variable_lifetime
: lifetime
{ LexicalScope*scope = pform_peek_scope();
if (dynamic_cast<PPackage*>(scope)) {
@ -3071,6 +3083,10 @@ variable_lifetime_opt
}
var_lifetime = $1;
}
;
variable_lifetime_opt
: variable_lifetime
|
;
@ -3147,14 +3163,39 @@ block_item_decl
var_lifetime = LexicalScope::INHERITED;
}
| K_const_opt variable_lifetime_opt data_type list_of_variable_decl_assignments ';'
{ if ($3) pform_make_var(@3, $4, $3, attributes_in_context, $1);
| K_const variable_lifetime_opt data_type list_of_variable_decl_assignments ';'
{ if ($3) pform_make_var(@3, $4, $3, attributes_in_context, true);
var_lifetime = LexicalScope::INHERITED;
}
| variable_lifetime data_type list_of_variable_decl_assignments ';'
{ if ($2) pform_make_var(@2, $3, $2, attributes_in_context, false);
var_lifetime = LexicalScope::INHERITED;
}
| reg_prefixed_atomic_type list_of_variable_decl_assignments ';'
{ if ($1) pform_make_var(@1, $2, $1, attributes_in_context, false);
var_lifetime = LexicalScope::INHERITED;
}
| K_reg block_reg_data_type list_of_variable_decl_assignments ';'
{ if ($2) pform_make_var(@1, $3, $2, attributes_in_context, false);
var_lifetime = LexicalScope::INHERITED;
}
| ps_type_identifier_dim list_of_variable_decl_assignments ';'
{ if ($1) pform_make_var(@1, $2, $1, attributes_in_context, false);
var_lifetime = LexicalScope::INHERITED;
}
/* The extra `reg` is not valid (System)Verilog, this is an iverilog extension. */
| K_const_opt variable_lifetime_opt K_reg reg_prefixed_atomic_type list_of_variable_decl_assignments ';'
{ if ($4) pform_make_var(@4, $5, $4, attributes_in_context, $1);
| K_const variable_lifetime_opt K_reg reg_prefixed_atomic_type list_of_variable_decl_assignments ';'
{ if ($4) pform_make_var(@4, $5, $4, attributes_in_context, true);
var_lifetime = LexicalScope::INHERITED;
}
| variable_lifetime K_reg reg_prefixed_atomic_type list_of_variable_decl_assignments ';'
{ if ($3) pform_make_var(@3, $4, $3, attributes_in_context, false);
var_lifetime = LexicalScope::INHERITED;
}
@ -3174,7 +3215,23 @@ block_item_decl
/* Recover from errors that happen within variable lists. Use the
trailing semi-colon to resync the parser. */
| K_const_opt variable_lifetime_opt data_type error ';'
| K_const variable_lifetime_opt data_type error ';'
{ yyerror(@1, "error: Syntax error in variable list.");
yyerrok;
}
| variable_lifetime data_type error ';'
{ yyerror(@1, "error: Syntax error in variable list.");
yyerrok;
}
| reg_prefixed_atomic_type error ';'
{ yyerror(@1, "error: Syntax error in variable list.");
yyerrok;
}
| K_reg block_reg_data_type error ';'
{ yyerror(@1, "error: Syntax error in variable list.");
yyerrok;
}
| ps_type_identifier_dim error ';'
{ yyerror(@1, "error: Syntax error in variable list.");
yyerrok;
}