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32#include "gcc-common.h"
33
34
35#define TYPE_USERSPACE(TYPE) TYPE_LANG_FLAG_5(TYPE)
36
37__visible int plugin_is_GPL_compatible;
38
39static struct plugin_info structleak_plugin_info = {
40 .version = "20190125vanilla",
41 .help = "disable\tdo not activate plugin\n"
42 "byref\tinit structs passed by reference\n"
43 "byref-all\tinit anything passed by reference\n"
44 "verbose\tprint all initialized variables\n",
45};
46
47#define BYREF_STRUCT 1
48#define BYREF_ALL 2
49
50static bool verbose;
51static int byref;
52
53static tree handle_user_attribute(tree *node, tree name, tree args, int flags, bool *no_add_attrs)
54{
55 *no_add_attrs = true;
56
57
58 if (TREE_CODE(*node) != FIELD_DECL)
59 return NULL_TREE;
60
61 *no_add_attrs = false;
62 return NULL_TREE;
63}
64
65static struct attribute_spec user_attr = { };
66
67static void register_attributes(void *event_data, void *data)
68{
69 user_attr.name = "user";
70 user_attr.handler = handle_user_attribute;
71 user_attr.affects_type_identity = true;
72
73 register_attribute(&user_attr);
74}
75
76static tree get_field_type(tree field)
77{
78 return strip_array_types(TREE_TYPE(field));
79}
80
81static bool is_userspace_type(tree type)
82{
83 tree field;
84
85 for (field = TYPE_FIELDS(type); field; field = TREE_CHAIN(field)) {
86 tree fieldtype = get_field_type(field);
87 enum tree_code code = TREE_CODE(fieldtype);
88
89 if (code == RECORD_TYPE || code == UNION_TYPE)
90 if (is_userspace_type(fieldtype))
91 return true;
92
93 if (lookup_attribute("user", DECL_ATTRIBUTES(field)))
94 return true;
95 }
96 return false;
97}
98
99static void finish_type(void *event_data, void *data)
100{
101 tree type = (tree)event_data;
102
103 if (type == NULL_TREE || type == error_mark_node)
104 return;
105
106#if BUILDING_GCC_VERSION >= 5000
107 if (TREE_CODE(type) == ENUMERAL_TYPE)
108 return;
109#endif
110
111 if (TYPE_USERSPACE(type))
112 return;
113
114 if (is_userspace_type(type))
115 TYPE_USERSPACE(type) = 1;
116}
117
118static void initialize(tree var)
119{
120 basic_block bb;
121 gimple_stmt_iterator gsi;
122 tree initializer;
123 gimple init_stmt;
124 tree type;
125
126
127 bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun));
128
129
130 for (gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi)) {
131 gimple stmt = gsi_stmt(gsi);
132 tree rhs1;
133
134
135 if (!gimple_assign_single_p(stmt))
136 continue;
137 rhs1 = gimple_assign_rhs1(stmt);
138
139 if (TREE_CLOBBER_P(rhs1))
140 continue;
141
142 if (gimple_get_lhs(stmt) != var)
143 continue;
144
145 if (TREE_CODE(rhs1) == CONSTRUCTOR)
146 return;
147 }
148
149
150 if (verbose)
151 inform(DECL_SOURCE_LOCATION(var),
152 "%s variable will be forcibly initialized",
153 (byref && TREE_ADDRESSABLE(var)) ? "byref"
154 : "userspace");
155
156
157 type = TREE_TYPE(var);
158 if (AGGREGATE_TYPE_P(type))
159 initializer = build_constructor(type, NULL);
160 else
161 initializer = fold_convert(type, integer_zero_node);
162
163
164 init_stmt = gimple_build_assign(var, initializer);
165 gsi = gsi_after_labels(single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun)));
166 gsi_insert_before(&gsi, init_stmt, GSI_NEW_STMT);
167 update_stmt(init_stmt);
168}
169
170static unsigned int structleak_execute(void)
171{
172 basic_block bb;
173 tree var;
174 unsigned int i;
175
176
177 gcc_assert(single_succ_p(ENTRY_BLOCK_PTR_FOR_FN(cfun)));
178 bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun));
179 if (!single_pred_p(bb)) {
180 split_edge(single_succ_edge(ENTRY_BLOCK_PTR_FOR_FN(cfun)));
181 gcc_assert(single_succ_p(ENTRY_BLOCK_PTR_FOR_FN(cfun)));
182 }
183
184
185 FOR_EACH_LOCAL_DECL(cfun, i, var) {
186 tree type = TREE_TYPE(var);
187
188 gcc_assert(DECL_P(var));
189 if (!auto_var_in_fn_p(var, current_function_decl))
190 continue;
191
192
193 if (byref != BYREF_ALL && TREE_CODE(type) != RECORD_TYPE && TREE_CODE(type) != UNION_TYPE)
194 continue;
195
196
197 if (TYPE_USERSPACE(type) ||
198 (byref && TREE_ADDRESSABLE(var)))
199 initialize(var);
200 }
201
202 return 0;
203}
204
205#define PASS_NAME structleak
206#define NO_GATE
207#define PROPERTIES_REQUIRED PROP_cfg
208#define TODO_FLAGS_FINISH TODO_verify_il | TODO_verify_ssa | TODO_verify_stmts | TODO_dump_func | TODO_remove_unused_locals | TODO_update_ssa | TODO_ggc_collect | TODO_verify_flow
209#include "gcc-generate-gimple-pass.h"
210
211__visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
212{
213 int i;
214 const char * const plugin_name = plugin_info->base_name;
215 const int argc = plugin_info->argc;
216 const struct plugin_argument * const argv = plugin_info->argv;
217 bool enable = true;
218
219 PASS_INFO(structleak, "early_optimizations", 1, PASS_POS_INSERT_BEFORE);
220
221 if (!plugin_default_version_check(version, &gcc_version)) {
222 error(G_("incompatible gcc/plugin versions"));
223 return 1;
224 }
225
226 if (strncmp(lang_hooks.name, "GNU C", 5) && !strncmp(lang_hooks.name, "GNU C+", 6)) {
227 inform(UNKNOWN_LOCATION, G_("%s supports C only, not %s"), plugin_name, lang_hooks.name);
228 enable = false;
229 }
230
231 for (i = 0; i < argc; ++i) {
232 if (!strcmp(argv[i].key, "disable")) {
233 enable = false;
234 continue;
235 }
236 if (!strcmp(argv[i].key, "verbose")) {
237 verbose = true;
238 continue;
239 }
240 if (!strcmp(argv[i].key, "byref")) {
241 byref = BYREF_STRUCT;
242 continue;
243 }
244 if (!strcmp(argv[i].key, "byref-all")) {
245 byref = BYREF_ALL;
246 continue;
247 }
248 error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);
249 }
250
251 register_callback(plugin_name, PLUGIN_INFO, NULL, &structleak_plugin_info);
252 if (enable) {
253 register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &structleak_pass_info);
254 register_callback(plugin_name, PLUGIN_FINISH_TYPE, finish_type, NULL);
255 }
256 register_callback(plugin_name, PLUGIN_ATTRIBUTES, register_attributes, NULL);
257
258 return 0;
259}
260
