[PATCH 1/5] widl: Use explicit %empty token for empty rules.

[Rémi Bernon]

From: Rémi Bernon

---
 tools/widl/parser.y | 89 ++++++++++++++++++++++++++++++---------------
 1 file changed, 60 insertions(+), 29 deletions(-)

diff --git a/tools/widl/parser.y b/tools/widl/parser.y
index c483eb06ff0..73ff249a993 100644
--- a/tools/widl/parser.y
+++ b/tools/widl/parser.y
@@ -366,9 +366,13 @@ input: gbl_statements m_acf			{ $1 = append_parameterized_type_stmts($1);
    					}
    ;

-m_acf: /* empty */ | aACF acf_statements
+m_acf
+	: %empty
+	| aACF acf_statements
+	;

-decl_statements:				{ $$ = NULL; }
+decl_statements
+	: %empty				{ $$ = NULL; }
    | decl_statements tINTERFACE qualified_type '<' parameterized_type_args '>' ';'
    					{ parameterized_type_stmts = append_statement(parameterized_type_stmts, make_statement_parameterized_type($3, $5));
    					  $$ = append_statement($1, make_statement_reference(type_parameterized_type_specialize_declare($3, $5)));
@@ -376,15 +380,18 @@ decl_statements:				{ $$ = NULL; }
    ;

decl_block: tDECLARE '{' decl_statements '}' { $$ = $3; }
+	;

-imp_decl_statements:				{ $$ = NULL; }
+imp_decl_statements
+	: %empty				{ $$ = NULL; }
    | imp_decl_statements tINTERFACE qualified_type '<' parameterized_type_args '>' ';'
    					{ $$ = append_statement($1, make_statement_reference(type_parameterized_type_specialize_declare($3, $5))); }
    ;

imp_decl_block: tDECLARE '{' imp_decl_statements '}' { $$ = $3; }

-gbl_statements:					{ $$ = NULL; }
+gbl_statements
+	: %empty				{ $$ = NULL; }
    | gbl_statements namespacedef '{' { push_namespaces($2); } gbl_statements '}'
    					{ pop_namespaces($2); $$ = append_statements($1, $5); }
    | gbl_statements interface ';'		{ $$ = append_statement($1, make_statement_reference($2)); }
@@ -409,7 +416,8 @@ gbl_statements:					{ $$ = NULL; }
    | gbl_statements decl_block		{ $$ = append_statements($1, $2); }
    ;

-imp_statements:					{ $$ = NULL; }
+imp_statements
+	: %empty				{ $$ = NULL; }
    | imp_statements interface ';'		{ $$ = append_statement($1, make_statement_reference($2)); }
    | imp_statements dispinterface ';'	{ $$ = append_statement($1, make_statement_reference($2)); }
    | imp_statements namespacedef '{' { push_namespaces($2); } imp_statements '}'
@@ -433,11 +441,13 @@ imp_statements:					{ $$ = NULL; }
    | imp_statements imp_decl_block		{ $$ = append_statements($1, $2); }
    ;

-int_statements:					{ $$ = NULL; }
+int_statements
+	: %empty				{ $$ = NULL; }
    | int_statements statement		{ $$ = append_statement($1, $2); }
    ;

-semicolon_opt:
+semicolon_opt
+	: %empty
    | ';'
    ;

@@ -512,7 +522,8 @@ librarydef: library_start imp_statements '}'
        semicolon_opt			{ $$ = $1; $$->stmts = $2; }
    ;

-m_args:						{ $$ = NULL; }
+m_args
+	: %empty				{ $$ = NULL; }
    | args
    ;

@@ -545,7 +556,8 @@ array:	  '[' expr ']'				{ $$ = $2;
    | '[' ']'				{ $$ = make_expr(EXPR_VOID); }
    ;

-m_attributes:					{ $$ = NULL; }
+m_attributes
+	: %empty				{ $$ = NULL; }
    | attributes
    ;

@@ -590,8 +602,10 @@ activatable_attr:
    					  $$ = make_exprt(EXPR_MEMBER, declare_var(NULL, $1, make_declarator(NULL), 0), $3);
    					}
    | contract_req				{ $$ = $1; } /* activatable on the default activation factory */
+	;

-attribute:					{ $$ = NULL; }
+attribute
+	: %empty				{ $$ = NULL; }
    | tACTIVATABLE '(' activatable_attr ')'	{ $$ = make_attrp(ATTR_ACTIVATABLE, $3); }
    | tAGGREGATABLE				{ $$ = make_attr(ATTR_AGGREGATABLE); }
    | tANNOTATION '(' aSTRING ')'		{ $$ = make_attrp(ATTR_ANNOTATION, $3); }
@@ -723,7 +737,8 @@ callconv: tCDECL				{ $$ = xstrdup("__cdecl"); }
    | tSTDCALL				{ $$ = xstrdup("__stdcall"); }
    ;

-cases:						{ $$ = NULL; }
+cases
+	: %empty				{ $$ = NULL; }
    | cases case				{ $$ = append_var( $1, $2 ); }
    ;

@@ -737,7 +752,8 @@ case:	  tCASE expr_int_const ':' union_field	{ attr_t *a = make_attrp(ATTR_CASE,
    					}
    ;

-enums:						{ $$ = NULL; }
+enums
+	: %empty				{ $$ = NULL; }
    | enum_list ','				{ $$ = $1; }
    | enum_list
    ;
@@ -779,7 +795,8 @@ m_exprs:  m_expr                                { $$ = append_expr( NULL, $1 );
    | m_exprs ',' m_expr                    { $$ = append_expr( $1, $3 ); }
    ;

-m_expr:						{ $$ = make_expr(EXPR_VOID); }
+m_expr
+	: %empty				{ $$ = make_expr(EXPR_VOID); }
    | expr
    ;

@@ -844,7 +861,8 @@ expr_const: expr				{ $$ = $1;
    					}
    ;

-fields:						{ $$ = NULL; }
+fields
+	: %empty				{ $$ = NULL; }
    | fields field				{ $$ = append_var_list($1, $2); }
    ;

@@ -864,7 +882,8 @@ ne_union_field:
    | attributes ';'			{ $$ = make_var(NULL); $$->attrs = $1; }
         ;

-ne_union_fields:				{ $$ = NULL; }
+ne_union_fields
+	: %empty				{ $$ = NULL; }
    | ne_union_fields ne_union_field	{ $$ = append_var( $1, $2 ); }
    ;

@@ -900,11 +919,13 @@ declaration:
    					}
    ;

-m_ident:					{ $$ = NULL; }
+m_ident
+	: %empty				{ $$ = NULL; }
    | ident
    ;

-m_typename:					{ $$ = NULL; }
+m_typename
+	: %empty				{ $$ = NULL; }
    | typename
    ;

@@ -928,7 +949,8 @@ base_type: tBYTE				{ $$ = find_type_or_error(NULL, $<str>1); }
    | tHANDLET				{ $$ = find_type_or_error(NULL, $<str>1); }
    ;

-m_int:
+m_int
+	: %empty
    | tINT
    ;

@@ -996,7 +1018,8 @@ namespacedef: tNAMESPACE aIDENTIFIER		{ $$ = append_str( NULL, $2 ); }
    | namespacedef '.' aIDENTIFIER		{ $$ = append_str( $1, $3 ); }
    ;

-class_interfaces:				{ $$ = NULL; }
+class_interfaces
+	: %empty				{ $$ = NULL; }
    | class_interfaces class_interface	{ $$ = append_typeref( $1, $2 ); }
    ;

@@ -1026,7 +1049,8 @@ dispinterfacedef:
    					{ $$ = type_dispinterface_define_from_iface($2, $1, $4); }
    ;

-inherit:					{ $$ = NULL; }
+inherit
+	: %empty				{ $$ = NULL; }
    | ':' qualified_type                    { $$ = $2; }
    | ':' parameterized_type		{ $$ = $2; }
    ;
@@ -1062,8 +1086,10 @@ required_types:
    | parameterized_type			{ $$ = append_typeref(NULL, make_typeref($1)); }
    | required_types ',' qualified_type	{ $$ = append_typeref($1, make_typeref($3)); }
    | required_types ',' parameterized_type	{ $$ = append_typeref($1, make_typeref($3)); }
+	;

-requires:					{ $$ = NULL; }
+requires
+	: %empty				{ $$ = NULL; }
    | tREQUIRES required_types		{ $$ = $2; }
    ;

@@ -1114,7 +1140,8 @@ type_qualifier:
      tCONST				{ $$ = TYPE_QUALIFIER_CONST; }
    ;

-m_type_qual_list:				{ $$ = 0; }
+m_type_qual_list
+	: %empty				{ $$ = 0; }
    | m_type_qual_list type_qualifier	{ $$ = $1 | $2; }
    ;

@@ -1129,7 +1156,8 @@ unqualified_decl_spec: unqualified_type m_decl_spec_no_type
    					{ $$ = make_decl_spec($2, $1, $3, STG_NONE, 0, 0); }
    ;

-m_decl_spec_no_type:				{ $$ = NULL; }
+m_decl_spec_no_type
+	: %empty				{ $$ = NULL; }
    | decl_spec_no_type
    ;

@@ -1169,7 +1197,8 @@ abstract_declarator_no_direct:
    ;

/* abstract declarator or empty */
-m_abstract_declarator: 				{ $$ = make_declarator(NULL); }
+m_abstract_declarator
+	: %empty 				{ $$ = make_declarator(NULL); }
    | abstract_declarator
    ;

@@ -1204,7 +1233,8 @@ any_declarator_no_direct:
    ;

/* abstract or non-abstract declarator or empty */
-m_any_declarator: 				{ $$ = make_declarator(NULL); }
+m_any_declarator
+	: %empty 				{ $$ = make_declarator(NULL); }
    | any_declarator
    ;

@@ -1231,7 +1261,8 @@ declarator_list:
    | declarator_list ',' declarator	{ $$ = append_declarator( $1, $3 ); }
    ;

-m_bitfield:					{ $$ = NULL; }
+m_bitfield
+	: %empty				{ $$ = NULL; }
    | ':' expr_const			{ $$ = $2; }
    ;

@@ -1310,12 +1341,12 @@ version:
    ;

acf_statements
-        : /* empty */
+        : %empty
         | acf_interface acf_statements
    ;

acf_int_statements
-        : /* empty */
+        : %empty
         | acf_int_statement acf_int_statements
    ;

@@ -1336,7 +1367,7 @@ acf_interface
    ;

acf_attributes
-        : /* empty */                           { $$ = NULL; };
+        : %empty                                { $$ = NULL; };
         | '[' acf_attribute_list ']'            { $$ = $2; };
    ;