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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
(***********************************************************************)
(* *)
(* CamlIDL *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1999 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the GNU Lesser General Public License LGPL v2.1 *)
(* *)
(***********************************************************************)
(* $Id: union.ml,v 1.8 2002-01-16 09:42:04 xleroy Exp $ *)
(* Handling of unions *)
open Printf
open Utils
open Variables
open Idltypes
open Cvttyp
(* Translate an ML datatype [v] and store its argument in the C union [c]
and its discriminant in the C integer [discr]. *)
let union_ml_to_c ml_to_c oc onstack pref ud v c discr =
let tag_constant = ref 0
and tag_constr = ref 0 in
let emit_case = function
{case_field = None; case_labels = []} -> (* default case, no arg *)
iprintf oc "case %d: /* default */\n" !tag_constr;
incr tag_constr;
iprintf oc " %s = Int_val(Field(%s, 0));\n" discr v;
iprintf oc " break;\n"
| {case_field = Some{field_name = n; field_typ = ty}; case_labels = []} ->
(* default case, one arg *)
iprintf oc "case %d: /* default */\n" !tag_constr;
incr tag_constr;
increase_indent();
iprintf oc "%s = Int_val(Field(%s, 0));\n" discr v;
let v' = new_ml_variable() in
iprintf oc "%s = Field(%s, 1);\n" v' v;
ml_to_c oc onstack pref ty v' (sprintf "%s.%s" c n);
iprintf oc "break;\n";
decrease_indent()
| {case_field = None; case_labels = lbls} -> (* named case, no args *)
List.iter
(fun lbl ->
iprintf oc "case %d: /* %s */\n" !tag_constant lbl;
incr tag_constant;
iprintf oc " %s = %s;\n" discr lbl;
iprintf oc " break;\n")
lbls
| {case_field = Some{field_name = n; field_typ = ty}; case_labels = lbls} ->
(* named case, one arg *)
List.iter
(fun lbl ->
iprintf oc "case %d: /* %s */\n" !tag_constr lbl;
incr tag_constr;
increase_indent();
iprintf oc "%s = %s;\n" discr lbl;
let v' = new_ml_variable() in
iprintf oc "%s = Field(%s, 0);\n" v' v;
ml_to_c oc onstack pref ty v' (sprintf "%s.%s" c n);
iprintf oc "break;\n";
decrease_indent())
lbls in
let (constant_cases, constr_cases) =
list_partition
(fun c -> c.case_field = None && c.case_labels <> [])
ud.ud_cases in
if constant_cases <> [] && constr_cases <> [] then begin
iprintf oc "if (Is_long(%s)) {\n" v;
increase_indent()
end;
if constant_cases <> [] then begin
iprintf oc "switch (Int_val(%s)) {\n" v;
List.iter emit_case constant_cases;
iprintf oc "}\n"
end;
if constant_cases <> [] && constr_cases <> [] then begin
decrease_indent();
iprintf oc "} else {\n";
increase_indent()
end;
if constr_cases <> [] then begin
iprintf oc "switch (Tag_val(%s)) {\n" v;
List.iter emit_case constr_cases;
iprintf oc "}\n"
end;
if constant_cases <> [] && constr_cases <> [] then begin
decrease_indent();
iprintf oc "}\n"
end
(* Translate a C union [c] with its discriminant [discr]
to an ML datatype [v]. *)
let union_c_to_ml c_to_ml oc pref ud c v discr =
let tag_constant = ref 0 and tag_constr = ref 0 in
let have_default = ref false in
let emit_case = function
{case_field = None; case_labels = []} -> (* default case, no arg *)
iprintf oc "default:\n";
increase_indent();
iprintf oc "%s = camlidl_alloc_small(1, %d);\n" v !tag_constr;
incr tag_constr;
iprintf oc "Field(%s, 0) = Val_int(%s);\n" v discr;
iprintf oc "break;\n";
decrease_indent();
have_default := true
| {case_field = Some{field_name = n; field_typ = ty}; case_labels = []} ->
(* default case, one arg *)
iprintf oc "default:\n";
increase_indent();
let v' = new_ml_variable() in
c_to_ml oc pref ty (sprintf "%s.%s" c n) v';
iprintf oc "Begin_root(%s)\n" v';
increase_indent();
iprintf oc "%s = camlidl_alloc_small(2, %d);\n" v !tag_constr;
incr tag_constr;
iprintf oc "Field(%s, 0) = Val_int(%s);\n" v discr;
iprintf oc "Field(%s, 1) = %s;\n" v v';
decrease_indent();
iprintf oc "End_roots()\n";
iprintf oc "break;\n";
decrease_indent();
have_default := true
| {case_field = None; case_labels = lbls} -> (* named cases, no arg *)
List.iter
(fun lbl ->
iprintf oc "case %s:\n" lbl;
iprintf oc " %s = Val_int(%d);\n" v !tag_constant;
incr tag_constant;
iprintf oc " break;\n")
lbls;
| {case_field = Some{field_name = n; field_typ = ty}; case_labels = lbls} ->
(* named cases, one arg *)
List.iter
(fun lbl ->
iprintf oc "case %s:\n" lbl;
increase_indent();
let v' = new_ml_variable() in
c_to_ml oc pref ty (sprintf "%s.%s" c n) v';
iprintf oc "Begin_root(%s)\n" v';
increase_indent();
iprintf oc "%s = camlidl_alloc_small(1, %d);\n" v !tag_constr;
incr tag_constr;
iprintf oc "Field(%s, 0) = %s;\n" v v';
decrease_indent();
iprintf oc "End_roots()\n";
iprintf oc "break;\n";
decrease_indent())
lbls in
iprintf oc "switch (%s) {\n" discr;
List.iter emit_case ud.ud_cases;
if not !have_default then begin
iprintf oc "default:\n";
iprintf oc " caml_invalid_argument(\"%s: bad discriminant for union %s\");\n"
!current_function ud.ud_name
end;
iprintf oc "}\n"
|
