1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
%union {
Scope *scope;
Expr *expr;
Expr_List *elist;
Type *type;
Decl *decl;
Decl_List *dlist;
Code *code;
char *id;
};
%left '+' '-'
%left '*' '/' '%'
%nonassoc PREFIX
%nonassoc POSTFIX '(' '[' '.'
%token <id> ID
%token <expr> CONSTANT
%token EXTERN REGISTER STATIC CONST VOLATILE IF THEN ELSE CLCL
%type <expr> expr(<scope>)
%type decl(<scope>) declarator_list(<scope>, <type>)
decl_list(<scope>)
%type <code> statement(<scope>) statement_list(<scope>)
block_statement(<scope>)
%type <decl> declarator(<scope>, <type>) formal_arg(<scope>)
%type <type> decl_specs(<scope>) decl_spec(<scope>) typename(<scope>)
cv_quals cv_qual
%type <scope> opt_scope(<scope>)
%type <dlist> formal_arg_list(<scope>) nonempty_formal_arg_list(<scope>)
%start input
%%
opt_scope($e): [ $$ = $e; ]
| CLCL [ $$ = global_scope; ]
| opt_scope ID CLCL [ Decl *d = lookup($1, $2);
if (!d || !d->scope) YERROR;
$$ = d->scope; ]
;
typename($e): opt_scope ID
[ Decl *d = lookup($1, $2);
if (!d || !d->istype()) YYERROR;
$$ = d->type; ]
;
input: decl_list(global_scope = new_scope(0)) ;
decl_list($e): | decl_list decl($e) ;
decl($e):
decl_specs declarator_list($e,$1) ';' [YYVALID;]
| decl_specs declarator($e,$1) block_statement(start_fn_def($e, $2))
{ finish_fn_def($2, $3); }
;
decl_specs($e):
decl_spec [ $$ = $1; ]
| decl_specs decl_spec($e) [ $$ = type_combine($1, $2); ]
;
cv_quals: [ $$ = 0; ]
| cv_quals cv_qual [ $$ = type_combine($1, $2); ]
;
decl_spec($e):
cv_qual [ $$ = $1; ]
| typename [ $$ = $1; ]
| EXTERN [ $$ = bare_extern(); ]
| REGISTER [ $$ = bare_register(); ]
| STATIC [ $$ = bare_static(); ]
;
cv_qual:
CONST [ $$ = bare_const(); ]
| VOLATILE [ $$ = bare_volatile(); ]
;
declarator_list($e, $t):
declarator_list ',' declarator($e, $t)
| declarator
;
declarator($e, $t):
/* empty */ [ if (!$t) YYERROR; ]
{ $$ = declare($e, 0, $t); }
| ID { $$ = declare($e, $1, $t); }
| '(' declarator($e, $t) ')' { $$ = $2; }
| '*' cv_quals declarator($e, $t) %prec PREFIX
{ $$ = make_pointer($3, $2); }
| declarator '[' expr($e) ']'
{ $$ = make_array($1->type, $3); }
| declarator '(' formal_arg_list($e) ')' cv_quals
{ $$ = build_function($1, $3, $5); }
;
formal_arg_list($e): { $$ = 0; }
| nonempty_formal_arg_list { $$ = $1; }
;
nonempty_formal_arg_list($e):
nonempty_formal_arg_list ',' formal_arg($e) { $$ = append_dlist($1, $3); }
| formal_arg { $$ = build_dlist($1); }
;
formal_arg($e):
decl_specs declarator($e,$1) { $$ = $2; }
;
expr($e):
expr '+' expr($e) { $$ = build_expr($1, ADD, $3); }
| expr '-' expr($e) { $$ = build_expr($1, SUB, $3); }
| expr '*' expr($e) { $$ = build_expr($1, MUL, $3); }
| expr '%' expr($e) { $$ = build_expr($1, MOD, $3); }
| expr '/' expr($e) { $$ = build_expr($1, DIV, $3); }
| '*' expr($e) %prec PREFIX { $$ = build_expr(0, REF, $2); }
| ID { $$ = var_expr($e, $1); }
| CONSTANT { $$ = $1; }
;
statement($e):
decl { $$ = 0; }
| expr($e) ';' [YYVALID;] { $$ = build_expr_code($1); }
| IF '(' expr($e) ')' THEN statement($e) ELSE statement($e) [YYVALID;]
{ $$ = build_if($3, $6, $8); }
| IF '(' expr($e) ')' THEN statement($e) [YYVALID;]
{ $$ = build_if($3, $6, 0); }
| block_statement(new_scope($e)) [YYVALID;]{ $$ = $1; }
;
statement_list($e): { $$ = 0; }
| statement_list statement($e) { $$ = code_append($1, $2); }
;
block_statement($e):
'{' statement_list($e) '}' { $$ = $2; }
;
|
