don't emit dead initializers
[cparser] / walk_statements.c
1 #include <config.h>
2
3 #include "adt/error.h"
4 #include "ast_t.h"
5 #include "entity_t.h"
6 #include "walk_statements.h"
7
8
9 static void walk_expression(expression_t const *const expr,
10                             statement_callback const callback, void *const env)
11 {
12         switch (expr->base.kind) {
13         case EXPR_STATEMENT:
14                 walk_statements(expr->statement.statement, callback, env);
15                 return;
16
17         EXPR_BINARY_CASES
18                 walk_expression(expr->binary.left,  callback, env);
19                 walk_expression(expr->binary.right, callback, env);
20                 return;
21
22         EXPR_UNARY_CASES_OPTIONAL
23                 if (expr->unary.value == NULL)
24                         return;
25                 /* FALLTHROUGH */
26         EXPR_UNARY_CASES_MANDATORY
27                 walk_expression(expr->unary.value, callback, env);
28                 return;
29
30         case EXPR_CALL:
31                 for (call_argument_t *arg = expr->call.arguments; arg != NULL;
32                      arg = arg->next) {
33                         walk_expression(arg->expression, callback, env);
34                 }
35                 return;
36
37         case EXPR_UNKNOWN:
38                 panic("unexpected expr kind");
39
40         case EXPR_COMPOUND_LITERAL:
41                 /* TODO... */
42                 break;
43
44         case EXPR_CONDITIONAL:
45                 walk_expression(expr->conditional.condition,        callback, env);
46                 /* may be NULL because of gnu extension */
47                 if (expr->conditional.true_expression != NULL)
48                         walk_expression(expr->conditional.true_expression,  callback, env);
49                 walk_expression(expr->conditional.false_expression, callback, env);
50                 return;
51
52         case EXPR_BUILTIN_CONSTANT_P:
53                 walk_expression(expr->builtin_constant.value, callback, env);
54                 return;
55
56         case EXPR_SELECT:
57                 walk_expression(expr->select.compound, callback, env);
58                 return;
59
60         case EXPR_ARRAY_ACCESS:
61                 walk_expression(expr->array_access.array_ref, callback, env);
62                 walk_expression(expr->array_access.index,     callback, env);
63                 return;
64
65         case EXPR_CLASSIFY_TYPE:
66                 walk_expression(expr->classify_type.type_expression, callback, env);
67                 return;
68
69         case EXPR_SIZEOF:
70         case EXPR_ALIGNOF: {
71                 expression_t *tp_expression = expr->typeprop.tp_expression;
72                 if (tp_expression != NULL) {
73                         walk_expression(tp_expression, callback, env);
74                 }
75                 return;
76         }
77
78         case EXPR_VA_START:
79                 walk_expression(expr->va_starte.ap, callback, env);
80                 return;
81
82         case EXPR_VA_ARG:
83                 walk_expression(expr->va_arge.ap, callback, env);
84                 return;
85
86         case EXPR_VA_COPY:
87                 walk_expression(expr->va_copye.src, callback, env);
88                 walk_expression(expr->va_copye.dst, callback, env);
89                 return;
90
91         case EXPR_INVALID:
92         case EXPR_OFFSETOF:
93         case EXPR_REFERENCE:
94         case EXPR_REFERENCE_ENUM_VALUE:
95         case EXPR_CONST:
96         case EXPR_CHARACTER_CONSTANT:
97         case EXPR_WIDE_CHARACTER_CONSTANT:
98         case EXPR_STRING_LITERAL:
99         case EXPR_WIDE_STRING_LITERAL:
100         case EXPR_FUNCNAME:
101         case EXPR_LABEL_ADDRESS:
102         case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
103                 break;
104         }
105
106         /* TODO FIXME: implement all the missing expressions here */
107 }
108
109 static void walk_initializer(const initializer_t  *initializer,
110                              statement_callback    callback,
111                                                          void                 *env)
112 {
113         switch(initializer->kind) {
114         case INITIALIZER_VALUE:
115                 walk_expression(initializer->value.value, callback, env);
116                 return;
117         default:
118                 /* FIXME: should walk initializer hierarchies... */
119                 break;
120         }
121 }
122
123 static void walk_declarations(const entity_t*            entity,
124                               const entity_t*      const last,
125                               statement_callback   const callback,
126                               void                *const env)
127 {
128         entity_t const *const end = last != NULL ? last->base.next : NULL;
129         for (; entity != end; entity = entity->base.next) {
130                 /* we only look at variables */
131                 if (entity->kind != ENTITY_VARIABLE)
132                         continue;
133
134                 const variable_t    *variable    = &entity->variable;
135                 const initializer_t *initializer = variable->initializer;
136                 if (initializer != NULL) {
137                         walk_initializer(initializer, callback, env);
138                 }
139         }
140 }
141
142
143 void walk_statements(statement_t *const stmt, statement_callback const callback, void *const env)
144 {
145         callback(stmt, env);
146
147         switch (stmt->kind) {
148                 case STATEMENT_COMPOUND:
149                         for (statement_t *s = stmt->compound.statements; s != NULL; s = s->base.next) {
150                                 walk_statements(s, callback, env);
151                         }
152                         return;
153
154                 case STATEMENT_FOR:
155                         walk_declarations(stmt->fors.scope.entities, NULL, callback, env);
156                         if (stmt->fors.initialisation != NULL)
157                                 walk_expression(stmt->fors.initialisation, callback, env);
158                         if (stmt->fors.condition != NULL)
159                                 walk_expression(stmt->fors.condition, callback, env);
160                         if (stmt->fors.step != NULL)
161                                 walk_expression(stmt->fors.step, callback, env);
162                         walk_statements(stmt->fors.body,           callback, env);
163                         return;
164
165                 case STATEMENT_IF:
166                         walk_expression(stmt->ifs.condition,      callback, env);
167                         walk_statements(stmt->ifs.true_statement, callback, env);
168                         if (stmt->ifs.false_statement != NULL)
169                                 walk_statements(stmt->ifs.false_statement, callback, env);
170                         return;
171
172                 case STATEMENT_SWITCH:
173                         walk_expression(stmt->switchs.expression, callback, env);
174                         walk_statements(stmt->switchs.body,       callback, env);
175                         return;
176
177                 case STATEMENT_LABEL:
178                         walk_statements(stmt->label.statement, callback, env);
179                         return;
180
181                 case STATEMENT_CASE_LABEL:
182                         walk_statements(stmt->case_label.statement, callback, env);
183                         return;
184
185                 case STATEMENT_WHILE:
186                         walk_expression(stmt->whiles.condition, callback, env);
187                         walk_statements(stmt->whiles.body,      callback, env);
188                         return;
189
190                 case STATEMENT_DO_WHILE:
191                         walk_statements(stmt->do_while.body,      callback, env);
192                         walk_expression(stmt->do_while.condition, callback, env);
193                         return;
194
195                 case STATEMENT_EXPRESSION:
196                         walk_expression(stmt->expression.expression, callback, env);
197                         return;
198
199                 case STATEMENT_RETURN:
200                         if (stmt->returns.value != NULL)
201                                 walk_expression(stmt->returns.value, callback, env);
202                         return;
203
204                 case STATEMENT_DECLARATION:
205                         walk_declarations(stmt->declaration.declarations_begin,
206                                         stmt->declaration.declarations_end, callback, env);
207                         return;
208
209                 case STATEMENT_MS_TRY:
210                         walk_statements(stmt->ms_try.try_statement,   callback, env);
211                         walk_statements(stmt->ms_try.final_statement, callback, env);
212                         return;
213
214                 case STATEMENT_INVALID:
215                 case STATEMENT_EMPTY:
216                 case STATEMENT_CONTINUE:
217                 case STATEMENT_BREAK:
218                 case STATEMENT_GOTO:
219                 case STATEMENT_ASM:
220                 case STATEMENT_LEAVE:
221                         return;
222         }
223
224         panic("unhandled statement");
225 }