xref: /freebsd/contrib/xz/src/liblzma/common/common.h (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 /// \file       common.h
4 /// \brief      Definitions common to the whole liblzma library
5 //
6 //  Author:     Lasse Collin
7 //
8 //  This file has been put into the public domain.
9 //  You can do whatever you want with this file.
10 //
11 ///////////////////////////////////////////////////////////////////////////////
12 
13 #ifndef LZMA_COMMON_H
14 #define LZMA_COMMON_H
15 
16 #include "sysdefs.h"
17 #include "mythread.h"
18 #include "tuklib_integer.h"
19 
20 // LZMA_API_EXPORT is used to mark the exported API functions.
21 // It's used to define the LZMA_API macro.
22 //
23 // lzma_attr_visibility_hidden is used for marking *declarations* of extern
24 // variables that are internal to liblzma (-fvisibility=hidden alone is
25 // enough to hide the *definitions*). Such markings allow slightly more
26 // efficient code to accesses those variables in ELF shared libraries.
27 #if defined(_WIN32) || defined(__CYGWIN__)
28 #	ifdef DLL_EXPORT
29 #		define LZMA_API_EXPORT __declspec(dllexport)
30 #	else
31 #		define LZMA_API_EXPORT
32 #	endif
33 #	define lzma_attr_visibility_hidden
34 // Don't use ifdef or defined() below.
35 #elif HAVE_VISIBILITY
36 #	define LZMA_API_EXPORT __attribute__((__visibility__("default")))
37 #	define lzma_attr_visibility_hidden \
38 			__attribute__((__visibility__("hidden")))
39 #else
40 #	define LZMA_API_EXPORT
41 #	define lzma_attr_visibility_hidden
42 #endif
43 
44 #define LZMA_API(type) LZMA_API_EXPORT type LZMA_API_CALL
45 
46 #include "lzma.h"
47 
48 // This is for detecting modern GCC and Clang attributes
49 // like __symver__ in GCC >= 10.
50 #ifdef __has_attribute
51 #	define lzma_has_attribute(attr) __has_attribute(attr)
52 #else
53 #	define lzma_has_attribute(attr) 0
54 #endif
55 
56 // The extra symbol versioning in the C files may only be used when
57 // building a shared library. If HAVE_SYMBOL_VERSIONS_LINUX is defined
58 // to 2 then symbol versioning is done only if also PIC is defined.
59 // By default Libtool defines PIC when building a shared library and
60 // doesn't define it when building a static library but it can be
61 // overridden with --with-pic and --without-pic. configure let's rely
62 // on PIC if neither --with-pic or --without-pic was used.
63 #if defined(HAVE_SYMBOL_VERSIONS_LINUX) \
64 		&& (HAVE_SYMBOL_VERSIONS_LINUX == 2 && !defined(PIC))
65 #	undef HAVE_SYMBOL_VERSIONS_LINUX
66 #endif
67 
68 #ifdef HAVE_SYMBOL_VERSIONS_LINUX
69 // To keep link-time optimization (LTO, -flto) working with GCC,
70 // the __symver__ attribute must be used instead of __asm__(".symver ...").
71 // Otherwise the symbol versions may be lost, resulting in broken liblzma
72 // that has wrong default versions in the exported symbol list!
73 // The attribute was added in GCC 10; LTO with older GCC is not supported.
74 //
75 // To keep -Wmissing-prototypes happy, use LZMA_SYMVER_API only with function
76 // declarations (including those with __alias__ attribute) and LZMA_API with
77 // the function definitions. This means a little bit of silly copy-and-paste
78 // between declarations and definitions though.
79 //
80 // As of GCC 12.2, the __symver__ attribute supports only @ and @@ but the
81 // very convenient @@@ isn't supported (it's supported by GNU assembler
82 // since 2000). When using @@ instead of @@@, the internal name must not be
83 // the same as the external name to avoid problems in some situations. This
84 // is why "#define foo_52 foo" is needed for the default symbol versions.
85 //
86 // __has_attribute is supported before GCC 10 and it is supported in Clang 14
87 // too (which doesn't support __symver__) so use it to detect if __symver__
88 // is available. This should be far more reliable than looking at compiler
89 // version macros as nowadays especially __GNUC__ is defined by many compilers.
90 #	if lzma_has_attribute(__symver__)
91 #		define LZMA_SYMVER_API(extnamever, type, intname) \
92 			extern __attribute__((__symver__(extnamever))) \
93 					LZMA_API(type) intname
94 #	else
95 #		define LZMA_SYMVER_API(extnamever, type, intname) \
96 			__asm__(".symver " #intname "," extnamever); \
97 			extern LZMA_API(type) intname
98 #	endif
99 #endif
100 
101 // MSVC has __forceinline which shouldn't be combined with the inline keyword
102 // (results in a warning).
103 //
104 // GCC 3.1 added always_inline attribute so we don't need to check
105 // for __GNUC__ version. Similarly, all relevant Clang versions
106 // support it (at least Clang 3.0.0 does already).
107 // Other compilers might support too which also support __has_attribute
108 // (Solaris Studio) so do that check too.
109 #if defined(_MSC_VER)
110 #	define lzma_always_inline __forceinline
111 #elif defined(__GNUC__) || defined(__clang__) || defined(__INTEL_COMPILER) \
112 		|| lzma_has_attribute(__always_inline__)
113 #	define lzma_always_inline inline __attribute__((__always_inline__))
114 #else
115 #	define lzma_always_inline inline
116 #endif
117 
118 // These allow helping the compiler in some often-executed branches, whose
119 // result is almost always the same.
120 #ifdef __GNUC__
121 #	define likely(expr) __builtin_expect(expr, true)
122 #	define unlikely(expr) __builtin_expect(expr, false)
123 #else
124 #	define likely(expr) (expr)
125 #	define unlikely(expr) (expr)
126 #endif
127 
128 
129 /// Size of temporary buffers needed in some filters
130 #define LZMA_BUFFER_SIZE 4096
131 
132 
133 /// Maximum number of worker threads within one multithreaded component.
134 /// The limit exists solely to make it simpler to prevent integer overflows
135 /// when allocating structures etc. This should be big enough for now...
136 /// the code won't scale anywhere close to this number anyway.
137 #define LZMA_THREADS_MAX 16384
138 
139 
140 /// Starting value for memory usage estimates. Instead of calculating size
141 /// of _every_ structure and taking into account malloc() overhead etc., we
142 /// add a base size to all memory usage estimates. It's not very accurate
143 /// but should be easily good enough.
144 #define LZMA_MEMUSAGE_BASE (UINT64_C(1) << 15)
145 
146 /// Start of internal Filter ID space. These IDs must never be used
147 /// in Streams.
148 #define LZMA_FILTER_RESERVED_START (LZMA_VLI_C(1) << 62)
149 
150 
151 /// Supported flags that can be passed to lzma_stream_decoder(),
152 /// lzma_auto_decoder(), or lzma_stream_decoder_mt().
153 #define LZMA_SUPPORTED_FLAGS \
154 	( LZMA_TELL_NO_CHECK \
155 	| LZMA_TELL_UNSUPPORTED_CHECK \
156 	| LZMA_TELL_ANY_CHECK \
157 	| LZMA_IGNORE_CHECK \
158 	| LZMA_CONCATENATED \
159 	| LZMA_FAIL_FAST )
160 
161 
162 /// Largest valid lzma_action value as unsigned integer.
163 #define LZMA_ACTION_MAX ((unsigned int)(LZMA_FULL_BARRIER))
164 
165 
166 /// Special return value (lzma_ret) to indicate that a timeout was reached
167 /// and lzma_code() must not return LZMA_BUF_ERROR. This is converted to
168 /// LZMA_OK in lzma_code().
169 #define LZMA_TIMED_OUT LZMA_RET_INTERNAL1
170 
171 /// Special return value (lzma_ret) for use in stream_decoder_mt.c to
172 /// indicate Index was detected instead of a Block Header.
173 #define LZMA_INDEX_DETECTED LZMA_RET_INTERNAL2
174 
175 
176 typedef struct lzma_next_coder_s lzma_next_coder;
177 
178 typedef struct lzma_filter_info_s lzma_filter_info;
179 
180 
181 /// Type of a function used to initialize a filter encoder or decoder
182 typedef lzma_ret (*lzma_init_function)(
183 		lzma_next_coder *next, const lzma_allocator *allocator,
184 		const lzma_filter_info *filters);
185 
186 /// Type of a function to do some kind of coding work (filters, Stream,
187 /// Block encoders/decoders etc.). Some special coders use don't use both
188 /// input and output buffers, but for simplicity they still use this same
189 /// function prototype.
190 typedef lzma_ret (*lzma_code_function)(
191 		void *coder, const lzma_allocator *allocator,
192 		const uint8_t *restrict in, size_t *restrict in_pos,
193 		size_t in_size, uint8_t *restrict out,
194 		size_t *restrict out_pos, size_t out_size,
195 		lzma_action action);
196 
197 /// Type of a function to free the memory allocated for the coder
198 typedef void (*lzma_end_function)(
199 		void *coder, const lzma_allocator *allocator);
200 
201 
202 /// Raw coder validates and converts an array of lzma_filter structures to
203 /// an array of lzma_filter_info structures. This array is used with
204 /// lzma_next_filter_init to initialize the filter chain.
205 struct lzma_filter_info_s {
206 	/// Filter ID. This can be used to share the same initiazation
207 	/// function *and* data structures with different Filter IDs
208 	/// (LZMA_FILTER_LZMA1EXT does it), and also by the encoder
209 	/// with lzma_filters_update() if filter chain is updated
210 	/// in the middle of a raw stream or Block (LZMA_SYNC_FLUSH).
211 	lzma_vli id;
212 
213 	/// Pointer to function used to initialize the filter.
214 	/// This is NULL to indicate end of array.
215 	lzma_init_function init;
216 
217 	/// Pointer to filter's options structure
218 	void *options;
219 };
220 
221 
222 /// Hold data and function pointers of the next filter in the chain.
223 struct lzma_next_coder_s {
224 	/// Pointer to coder-specific data
225 	void *coder;
226 
227 	/// Filter ID. This is LZMA_VLI_UNKNOWN when this structure doesn't
228 	/// point to a filter coder.
229 	lzma_vli id;
230 
231 	/// "Pointer" to init function. This is never called here.
232 	/// We need only to detect if we are initializing a coder
233 	/// that was allocated earlier. See lzma_next_coder_init and
234 	/// lzma_next_strm_init macros in this file.
235 	uintptr_t init;
236 
237 	/// Pointer to function to do the actual coding
238 	lzma_code_function code;
239 
240 	/// Pointer to function to free lzma_next_coder.coder. This can
241 	/// be NULL; in that case, lzma_free is called to free
242 	/// lzma_next_coder.coder.
243 	lzma_end_function end;
244 
245 	/// Pointer to a function to get progress information. If this is NULL,
246 	/// lzma_stream.total_in and .total_out are used instead.
247 	void (*get_progress)(void *coder,
248 			uint64_t *progress_in, uint64_t *progress_out);
249 
250 	/// Pointer to function to return the type of the integrity check.
251 	/// Most coders won't support this.
252 	lzma_check (*get_check)(const void *coder);
253 
254 	/// Pointer to function to get and/or change the memory usage limit.
255 	/// If new_memlimit == 0, the limit is not changed.
256 	lzma_ret (*memconfig)(void *coder, uint64_t *memusage,
257 			uint64_t *old_memlimit, uint64_t new_memlimit);
258 
259 	/// Update the filter-specific options or the whole filter chain
260 	/// in the encoder.
261 	lzma_ret (*update)(void *coder, const lzma_allocator *allocator,
262 			const lzma_filter *filters,
263 			const lzma_filter *reversed_filters);
264 
265 	/// Set how many bytes of output this coder may produce at maximum.
266 	/// On success LZMA_OK must be returned.
267 	/// If the filter chain as a whole cannot support this feature,
268 	/// this must return LZMA_OPTIONS_ERROR.
269 	/// If no input has been given to the coder and the requested limit
270 	/// is too small, this must return LZMA_BUF_ERROR. If input has been
271 	/// seen, LZMA_OK is allowed too.
272 	lzma_ret (*set_out_limit)(void *coder, uint64_t *uncomp_size,
273 			uint64_t out_limit);
274 };
275 
276 
277 /// Macro to initialize lzma_next_coder structure
278 #define LZMA_NEXT_CODER_INIT \
279 	(lzma_next_coder){ \
280 		.coder = NULL, \
281 		.init = (uintptr_t)(NULL), \
282 		.id = LZMA_VLI_UNKNOWN, \
283 		.code = NULL, \
284 		.end = NULL, \
285 		.get_progress = NULL, \
286 		.get_check = NULL, \
287 		.memconfig = NULL, \
288 		.update = NULL, \
289 		.set_out_limit = NULL, \
290 	}
291 
292 
293 /// Internal data for lzma_strm_init, lzma_code, and lzma_end. A pointer to
294 /// this is stored in lzma_stream.
295 struct lzma_internal_s {
296 	/// The actual coder that should do something useful
297 	lzma_next_coder next;
298 
299 	/// Track the state of the coder. This is used to validate arguments
300 	/// so that the actual coders can rely on e.g. that LZMA_SYNC_FLUSH
301 	/// is used on every call to lzma_code until next.code has returned
302 	/// LZMA_STREAM_END.
303 	enum {
304 		ISEQ_RUN,
305 		ISEQ_SYNC_FLUSH,
306 		ISEQ_FULL_FLUSH,
307 		ISEQ_FINISH,
308 		ISEQ_FULL_BARRIER,
309 		ISEQ_END,
310 		ISEQ_ERROR,
311 	} sequence;
312 
313 	/// A copy of lzma_stream avail_in. This is used to verify that the
314 	/// amount of input doesn't change once e.g. LZMA_FINISH has been
315 	/// used.
316 	size_t avail_in;
317 
318 	/// Indicates which lzma_action values are allowed by next.code.
319 	bool supported_actions[LZMA_ACTION_MAX + 1];
320 
321 	/// If true, lzma_code will return LZMA_BUF_ERROR if no progress was
322 	/// made (no input consumed and no output produced by next.code).
323 	bool allow_buf_error;
324 };
325 
326 
327 /// Allocates memory
328 lzma_attr_alloc_size(1)
329 extern void *lzma_alloc(size_t size, const lzma_allocator *allocator);
330 
331 /// Allocates memory and zeroes it (like calloc()). This can be faster
332 /// than lzma_alloc() + memzero() while being backward compatible with
333 /// custom allocators.
334 lzma_attr_alloc_size(1)
335 extern void *lzma_alloc_zero(size_t size, const lzma_allocator *allocator);
336 
337 /// Frees memory
338 extern void lzma_free(void *ptr, const lzma_allocator *allocator);
339 
340 
341 /// Allocates strm->internal if it is NULL, and initializes *strm and
342 /// strm->internal. This function is only called via lzma_next_strm_init macro.
343 extern lzma_ret lzma_strm_init(lzma_stream *strm);
344 
345 /// Initializes the next filter in the chain, if any. This takes care of
346 /// freeing the memory of previously initialized filter if it is different
347 /// than the filter being initialized now. This way the actual filter
348 /// initialization functions don't need to use lzma_next_coder_init macro.
349 extern lzma_ret lzma_next_filter_init(lzma_next_coder *next,
350 		const lzma_allocator *allocator,
351 		const lzma_filter_info *filters);
352 
353 /// Update the next filter in the chain, if any. This checks that
354 /// the application is not trying to change the Filter IDs.
355 extern lzma_ret lzma_next_filter_update(
356 		lzma_next_coder *next, const lzma_allocator *allocator,
357 		const lzma_filter *reversed_filters);
358 
359 /// Frees the memory allocated for next->coder either using next->end or,
360 /// if next->end is NULL, using lzma_free.
361 extern void lzma_next_end(lzma_next_coder *next,
362 		const lzma_allocator *allocator);
363 
364 
365 /// Copy as much data as possible from in[] to out[] and update *in_pos
366 /// and *out_pos accordingly. Returns the number of bytes copied.
367 extern size_t lzma_bufcpy(const uint8_t *restrict in, size_t *restrict in_pos,
368 		size_t in_size, uint8_t *restrict out,
369 		size_t *restrict out_pos, size_t out_size);
370 
371 
372 /// \brief      Return if expression doesn't evaluate to LZMA_OK
373 ///
374 /// There are several situations where we want to return immediately
375 /// with the value of expr if it isn't LZMA_OK. This macro shortens
376 /// the code a little.
377 #define return_if_error(expr) \
378 do { \
379 	const lzma_ret ret_ = (expr); \
380 	if (ret_ != LZMA_OK) \
381 		return ret_; \
382 } while (0)
383 
384 
385 /// If next isn't already initialized, free the previous coder. Then mark
386 /// that next is _possibly_ initialized for the coder using this macro.
387 /// "Possibly" means that if e.g. allocation of next->coder fails, the
388 /// structure isn't actually initialized for this coder, but leaving
389 /// next->init to func is still OK.
390 #define lzma_next_coder_init(func, next, allocator) \
391 do { \
392 	if ((uintptr_t)(func) != (next)->init) \
393 		lzma_next_end(next, allocator); \
394 	(next)->init = (uintptr_t)(func); \
395 } while (0)
396 
397 
398 /// Initializes lzma_strm and calls func() to initialize strm->internal->next.
399 /// (The function being called will use lzma_next_coder_init()). If
400 /// initialization fails, memory that wasn't freed by func() is freed
401 /// along strm->internal.
402 #define lzma_next_strm_init(func, strm, ...) \
403 do { \
404 	return_if_error(lzma_strm_init(strm)); \
405 	const lzma_ret ret_ = func(&(strm)->internal->next, \
406 			(strm)->allocator, __VA_ARGS__); \
407 	if (ret_ != LZMA_OK) { \
408 		lzma_end(strm); \
409 		return ret_; \
410 	} \
411 } while (0)
412 
413 #endif
414