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
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- P A R . C H 1 1 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
pragma Style_Checks (All_Checks);
-- Turn off subprogram body ordering check. Subprograms are in order
-- by RM section rather than alphabetical
with Sinfo.CN; use Sinfo.CN;
separate (Par)
package body Ch11 is
-- Local functions, used only in this chapter
function P_Exception_Handler return Node_Id;
function P_Exception_Choice return Node_Id;
---------------------------------
-- 11.1 Exception Declaration --
---------------------------------
-- Parsed by P_Identifier_Declaration (3.3.1)
------------------------------------------
-- 11.2 Handled Sequence Of Statements --
------------------------------------------
-- HANDLED_SEQUENCE_OF_STATEMENTS ::=
-- SEQUENCE_OF_STATEMENTS
-- [exception
-- EXCEPTION_HANDLER
-- {EXCEPTION_HANDLER}]
-- Error_Recovery : Cannot raise Error_Resync
function P_Handled_Sequence_Of_Statements return Node_Id is
Handled_Stmt_Seq_Node : Node_Id;
begin
Handled_Stmt_Seq_Node :=
New_Node (N_Handled_Sequence_Of_Statements, Token_Ptr);
Set_Statements
(Handled_Stmt_Seq_Node, P_Sequence_Of_Statements (SS_Extm_Sreq));
if Token = Tok_Exception then
Scan; -- past EXCEPTION
Set_Exception_Handlers
(Handled_Stmt_Seq_Node, Parse_Exception_Handlers);
end if;
return Handled_Stmt_Seq_Node;
end P_Handled_Sequence_Of_Statements;
-----------------------------
-- 11.2 Exception Handler --
-----------------------------
-- EXCEPTION_HANDLER ::=
-- when [CHOICE_PARAMETER_SPECIFICATION :]
-- EXCEPTION_CHOICE {| EXCEPTION_CHOICE} =>
-- SEQUENCE_OF_STATEMENTS
-- CHOICE_PARAMETER_SPECIFICATION ::= DEFINING_IDENTIFIER
-- Error recovery: cannot raise Error_Resync
function P_Exception_Handler return Node_Id is
Scan_State : Saved_Scan_State;
Handler_Node : Node_Id;
Choice_Param_Node : Node_Id;
begin
Exception_Handler_Encountered := True;
Handler_Node := New_Node (N_Exception_Handler, Token_Ptr);
Set_Local_Raise_Statements (Handler_Node, No_Elist);
if Style_Check then
Style.Check_Indentation;
end if;
T_When;
-- Test for possible choice parameter present
if Token = Tok_Identifier then
Choice_Param_Node := Token_Node;
Save_Scan_State (Scan_State); -- at identifier
Scan; -- past identifier
if Token = Tok_Colon then
if Ada_Version = Ada_83 then
Error_Msg_SP ("(Ada 83) choice parameter not allowed!");
end if;
Scan; -- past :
Change_Identifier_To_Defining_Identifier (Choice_Param_Node);
Set_Choice_Parameter (Handler_Node, Choice_Param_Node);
elsif Token = Tok_Others then
Error_Msg_AP -- CODEFIX
("missing "":""");
Change_Identifier_To_Defining_Identifier (Choice_Param_Node);
Set_Choice_Parameter (Handler_Node, Choice_Param_Node);
else
Restore_Scan_State (Scan_State); -- to identifier
end if;
end if;
-- Loop through exception choices
Set_Exception_Choices (Handler_Node, New_List);
loop
Append (P_Exception_Choice, Exception_Choices (Handler_Node));
exit when Token /= Tok_Vertical_Bar;
Scan; -- past vertical bar
end loop;
TF_Arrow;
Set_Statements (Handler_Node, P_Sequence_Of_Statements (SS_Sreq_Whtm));
return Handler_Node;
end P_Exception_Handler;
------------------------------------------
-- 11.2 Choice Parameter Specification --
------------------------------------------
-- Parsed by P_Exception_Handler (11.2)
----------------------------
-- 11.2 Exception Choice --
----------------------------
-- EXCEPTION_CHOICE ::= exception_NAME | others
-- Error recovery: cannot raise Error_Resync. If an error occurs, then the
-- scan pointer is advanced to the next arrow or vertical bar or semicolon.
function P_Exception_Choice return Node_Id is
begin
if Token = Tok_Others then
Scan; -- past OTHERS
return New_Node (N_Others_Choice, Prev_Token_Ptr);
else
return P_Name; -- exception name
end if;
exception
when Error_Resync =>
Resync_Choice;
return Error;
end P_Exception_Choice;
---------------------------
-- 11.3 Raise Statement --
---------------------------
-- RAISE_STATEMENT ::= raise [exception_NAME];
-- The caller has verified that the initial token is RAISE
-- Error recovery: can raise Error_Resync
function P_Raise_Statement return Node_Id is
Raise_Node : Node_Id;
begin
Raise_Node := New_Node (N_Raise_Statement, Token_Ptr);
Scan; -- past RAISE
if Token /= Tok_Semicolon then
Set_Name (Raise_Node, P_Name);
end if;
if Token = Tok_With then
if Ada_Version < Ada_2005 then
Error_Msg_SC ("string expression in raise is Ada 2005 extension");
Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
end if;
Scan; -- past WITH
Set_Expression (Raise_Node, P_Expression);
end if;
TF_Semicolon;
return Raise_Node;
end P_Raise_Statement;
------------------------------
-- Parse_Exception_Handlers --
------------------------------
-- This routine scans out a list of exception handlers appearing in a
-- construct as:
-- exception
-- EXCEPTION_HANDLER {EXCEPTION_HANDLER}
-- The caller has scanned out the EXCEPTION keyword
-- Control returns after scanning the last exception handler, presumably
-- at the keyword END, but this is not checked in this routine.
-- Error recovery: cannot raise Error_Resync
function Parse_Exception_Handlers return List_Id is
Handler : Node_Id;
Handlers_List : List_Id;
begin
Handlers_List := New_List;
P_Pragmas_Opt (Handlers_List);
if Token = Tok_End then
Error_Msg_SC ("must have at least one exception handler!");
else
loop
Handler := P_Exception_Handler;
Append (Handler, Handlers_List);
-- Note: no need to check for pragmas here. Although the
-- syntax officially allows them in this position, they
-- will have been swallowed up as part of the statement
-- sequence of the handler we just scanned out.
exit when Token /= Tok_When;
end loop;
end if;
return Handlers_List;
end Parse_Exception_Handlers;
end Ch11;
|
