prototype.h revision 08cdf328add7b723b94b151866e5d0173662f6c6
1/*
2 * This file is part of ltrace.
3 * Copyright (C) 2012 Petr Machata, Red Hat Inc.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of the
8 * License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
18 * 02110-1301 USA
19 */
20
21#ifndef _PROTOTYPE_H_
22#define _PROTOTYPE_H_
23
24#include "forward.h"
25#include "dict.h"
26#include "vect.h"
27
28/* Function prototype.  */
29struct prototype {
30	/* Vector of struct param.  */
31	struct vect params;
32
33	struct arg_type_info *return_info;
34	int own_return_info : 1;
35};
36
37/* Initialize a prototype PROTO.  The name will be NAME, and the
38 * corresponding string will be owned and freed on destroy if
39 * OWN_NAME.  */
40void prototype_init(struct prototype *proto);
41
42/* Destroy PROTO (but don't free the memory block pointed-to by
43 * PROTO).  */
44void prototype_destroy(struct prototype *proto);
45
46/* Add new parameter PARAM to PROTO.  The structure contents are
47 * copied and PARAM pointer itself is not owned by PROTO.  */
48int prototype_push_param(struct prototype *proto, struct param *param);
49
50/* Return number of parameters of prototype.  */
51size_t prototype_num_params(struct prototype *proto);
52
53/* Destroy N-th parameter from PROTO.  N shall be smaller than the
54 * number of parameters.  */
55void prototype_destroy_nth_param(struct prototype *proto, size_t n);
56
57/* Get N-th parameter of PROTO.  N shall be smaller than the number of
58 * parameters.  */
59struct param *prototype_get_nth_param(struct prototype *proto, size_t n);
60
61/* Iterate through the parameters of PROTO.  See callback.h for notes
62 * on iteration interfaces.  */
63struct param *prototype_each_param
64	(struct prototype *proto, struct param *start_after,
65	 enum callback_status (*cb)(struct prototype *, struct param *, void *),
66	 void *data);
67
68/* For storing type aliases.  */
69struct named_type {
70	struct arg_type_info *info;
71	int forward : 1;
72	int own_type : 1;
73};
74
75/* Initialize a named type INFO, which, if OWN_TYPE, is destroyed when
76 * named_type_destroy is called.  */
77void named_type_init(struct named_type *named,
78		     struct arg_type_info *info, int own_type);
79
80void named_type_destroy(struct named_type *named);
81
82/* One prototype library.  */
83struct protolib {
84	/* Other libraries to look through if the definition is not
85	 * found here.  Note that due to the way imports are stored,
86	 * there is no way to distinguish where exactly (at which
87	 * place of the config file) the import was made.  */
88	struct vect imports;
89
90	/* Dictionary of name->struct prototype.  */
91	struct dict prototypes;
92
93	/* Dictionary of name->struct named_type.  */
94	struct dict named_types;
95};
96
97/* Initialize PLIB.  */
98void protolib_init(struct protolib *plib);
99
100/* Destroy PLIB.  */
101void protolib_destroy(struct protolib *plib);
102
103/* Push IMPORT to PLIB.  Returns 0 on success or a negative value on
104 * failure.  In particular, -2 is returned if mutual import is
105 * detected.  */
106int protolib_add_import(struct protolib *plib, struct protolib *import);
107
108/* Add a prototype PROTO to PLIB.  Returns 0 on success or a negative
109 * value on failure.  NAME is owned and released on PLIB destruction
110 * if OWN_NAME.  */
111int protolib_add_prototype(struct protolib *plib,
112			   const char *name, int own_name,
113			   struct prototype *proto);
114
115/* Add a named type NAMED to PLIB.  Returns 0 on success or a negative
116 * value on failure.  NAME is owned and released on PLIB destruction
117 * if OWN_NAME.  NAMED _pointer_ is copied to PLIB.  */
118int protolib_add_named_type(struct protolib *plib,
119			    const char *name, int own_name,
120			    struct named_type *named);
121
122/* Lookup prototype named NAME in PLIB.  If none is found, look
123 * recursively in each of the imports.  Returns the corresponding
124 * prototype, or NULL if none was found.  */
125struct prototype *protolib_lookup_prototype(struct protolib *plib,
126					    const char *name);
127
128/* Add a named type NAMED to PLIB.  Returns 0 on success or a negative
129 * value on failure.  */
130int protolib_add_type(struct protolib *plib, struct named_type *named);
131
132/* Lookup type named NAME in PLIB.  If none is found, look recursively
133 * in each of the imports.  Returns the corresponding type, or NULL if
134 * none was found.  */
135struct named_type *protolib_lookup_type(struct protolib *plib,
136					const char *name);
137
138/* A cache of prototype libraries.  Can load prototype libraries on
139 * demand.
140 *
141 * XXX ltrace should open one config per ABI, which maps long, int,
142 * etc. to uint32_t etc.  It would also map char to either of
143 * {u,}int8_t.  Other protolibs would have this as implicit import.
144 * That would mean that the cache needs ABI tagging--each ABI should
145 * have a separate prototype cache, because the types will potentially
146 * differ between the ABI's.  protolib cache would then naturally be
147 * stored in the ABI object, when this is introduced.  */
148struct protolib_cache {
149	/* Dictionary of filename->protolib*.  */
150	struct dict protolibs;
151
152	/* Fake module for implicit imports.  This is populated by all
153	 * files coming from -F.  When -F is empty, it also contains
154	 * either $HOME/.ltrace.conf, or /etc/ltrace.conf (whichever
155	 * comes first).  */
156	struct protolib imports;
157
158	/* For tracking uses of cache during cache's own
159	 * initialization.  */
160	int bootstrap : 1;
161};
162
163/* Initialize CACHE.  Returns 0 on success or a negative value on
164 * failure.  */
165int protolib_cache_init(struct protolib_cache *cache,
166			struct protolib *import);
167
168/* Destroy CACHE.  */
169void protolib_cache_destroy(struct protolib_cache *cache);
170
171/* Get protolib corresponding to KEY from CACHE.  KEY would typically
172 * be the soname of a library for which a protolib should be obtained.
173 * If none has been loaded yet, load a new protolib, cache and return
174 * it.  Returns NULL for failures.
175 *
176 * Protolibs are loaded from a config directory.  If -F contains
177 * directory names, those are checked first.  Next, os_get_config_dirs
178 * callback is used to get a list of directories to look into.  In the
179 * first round, if ALLOW_PRIVATE, ltrace looks in user's private
180 * directories.  If the config file wasn't found, the second round is
181 * made through system directories.  If it still wasn't found, an
182 * empty protolib (but with the following includes) is provided
183 * instead.
184 *
185 * In each directory, ltrace looks and reads the file named KEY.conf.
186 * This file is augmented with the following implicit includes, in
187 * this order:
188 *
189 * - Legacy typedefs
190 * - The INCLUDE argument passed to protolib_cache_init, if non-NULL
191 * - Any configure _files_ passed in -F
192 * - When looking into private directories, $HOME/.ltrace.conf
193 * - When looking into system directories, @sysconfdir@/ltrace.conf
194 *
195 * This function returns either the loaded protolib, or NULL when
196 * there was an error.  */
197struct protolib *protolib_cache_search(struct protolib_cache *cache,
198				       const char *key,
199				       int allow_private);
200
201/* This is similar to above, but instead of looking for the file to
202 * load in directories, the filename is given.  */
203struct protolib *protolib_cache_file(struct protolib_cache *cache,
204				     const char *filename);
205
206/* This is similar to protolib_cache_file, but the library to cache is
207 * given in argument.  Returns 0 on success or a negative value on
208 * failure.  PLIB is thereafter owned by CACHE.  */
209int protolib_cache_protolib(struct protolib_cache *cache,
210			    const char *filename,
211			    struct protolib *plib);
212
213/* Single global prototype cache.
214 *
215 * XXX Eventually each ABI should have its own cache.  The idea is
216 * that there's one per-ABI config file that all others use for
217 * elementary typedefs (long, char, size_t).  Ltrace then only deals
218 * in fixed-width integral types (and pointers etc.).  */
219extern struct protolib_cache g_protocache;
220
221void init_global_config(void);
222void destroy_global_config(void);
223
224#endif /* _PROTOTYPE_H_ */
225