xref: /freebsd/contrib/xz/src/liblzma/common/common.h (revision 783d3ff6)
1 // SPDX-License-Identifier: 0BSD
2 
3 ///////////////////////////////////////////////////////////////////////////////
4 //
5 /// \file       common.h
6 /// \brief      Definitions common to the whole liblzma library
7 //
8 //  Author:     Lasse Collin
9 //
10 ///////////////////////////////////////////////////////////////////////////////
11 
12 #ifndef LZMA_COMMON_H
13 #define LZMA_COMMON_H
14 
15 #include "sysdefs.h"
16 #include "mythread.h"
17 #include "tuklib_integer.h"
18 
19 // LZMA_API_EXPORT is used to mark the exported API functions.
20 // It's used to define the LZMA_API macro.
21 //
22 // lzma_attr_visibility_hidden is used for marking *declarations* of extern
23 // variables that are internal to liblzma (-fvisibility=hidden alone is
24 // enough to hide the *definitions*). Such markings allow slightly more
25 // efficient code to accesses those variables in ELF shared libraries.
26 #if defined(_WIN32) || defined(__CYGWIN__)
27 #	ifdef DLL_EXPORT
28 #		define LZMA_API_EXPORT __declspec(dllexport)
29 #	else
30 #		define LZMA_API_EXPORT
31 #	endif
32 #	define lzma_attr_visibility_hidden
33 // Don't use ifdef or defined() below.
34 #elif HAVE_VISIBILITY
35 #	define LZMA_API_EXPORT __attribute__((__visibility__("default")))
36 #	define lzma_attr_visibility_hidden \
37 			__attribute__((__visibility__("hidden")))
38 #else
39 #	define LZMA_API_EXPORT
40 #	define lzma_attr_visibility_hidden
41 #endif
42 
43 #define LZMA_API(type) LZMA_API_EXPORT type LZMA_API_CALL
44 
45 #include "lzma.h"
46 
47 // This is for detecting modern GCC and Clang attributes
48 // like __symver__ in GCC >= 10.
49 #ifdef __has_attribute
50 #	define lzma_has_attribute(attr) __has_attribute(attr)
51 #else
52 #	define lzma_has_attribute(attr) 0
53 #endif
54 
55 // The extra symbol versioning in the C files may only be used when
56 // building a shared library. If HAVE_SYMBOL_VERSIONS_LINUX is defined
57 // to 2 then symbol versioning is done only if also PIC is defined.
58 // By default Libtool defines PIC when building a shared library and
59 // doesn't define it when building a static library but it can be
60 // overridden with --with-pic and --without-pic. configure let's rely
61 // on PIC if neither --with-pic or --without-pic was used.
62 #if defined(HAVE_SYMBOL_VERSIONS_LINUX) \
63 		&& (HAVE_SYMBOL_VERSIONS_LINUX == 2 && !defined(PIC))
64 #	undef HAVE_SYMBOL_VERSIONS_LINUX
65 #endif
66 
67 #ifdef HAVE_SYMBOL_VERSIONS_LINUX
68 // To keep link-time optimization (LTO, -flto) working with GCC,
69 // the __symver__ attribute must be used instead of __asm__(".symver ...").
70 // Otherwise the symbol versions may be lost, resulting in broken liblzma
71 // that has wrong default versions in the exported symbol list!
72 // The attribute was added in GCC 10; LTO with older GCC is not supported.
73 //
74 // To keep -Wmissing-prototypes happy, use LZMA_SYMVER_API only with function
75 // declarations (including those with __alias__ attribute) and LZMA_API with
76 // the function definitions. This means a little bit of silly copy-and-paste
77 // between declarations and definitions though.
78 //
79 // As of GCC 12.2, the __symver__ attribute supports only @ and @@ but the
80 // very convenient @@@ isn't supported (it's supported by GNU assembler
81 // since 2000). When using @@ instead of @@@, the internal name must not be
82 // the same as the external name to avoid problems in some situations. This
83 // is why "#define foo_52 foo" is needed for the default symbol versions.
84 //
85 // __has_attribute is supported before GCC 10 and it is supported in Clang 14
86 // too (which doesn't support __symver__) so use it to detect if __symver__
87 // is available. This should be far more reliable than looking at compiler
88 // version macros as nowadays especially __GNUC__ is defined by many compilers.
89 #	if lzma_has_attribute(__symver__)
90 #		define LZMA_SYMVER_API(extnamever, type, intname) \
91 			extern __attribute__((__symver__(extnamever))) \
92 					LZMA_API(type) intname
93 #	else
94 #		define LZMA_SYMVER_API(extnamever, type, intname) \
95 			__asm__(".symver " #intname "," extnamever); \
96 			extern LZMA_API(type) intname
97 #	endif
98 #endif
99 
100 // MSVC has __forceinline which shouldn't be combined with the inline keyword
101 // (results in a warning).
102 //
103 // GCC 3.1 added always_inline attribute so we don't need to check
104 // for __GNUC__ version. Similarly, all relevant Clang versions
105 // support it (at least Clang 3.0.0 does already).
106 // Other compilers might support too which also support __has_attribute
107 // (Solaris Studio) so do that check too.
108 #if defined(_MSC_VER)
109 #	define lzma_always_inline __forceinline
110 #elif defined(__GNUC__) || defined(__clang__) || defined(__INTEL_COMPILER) \
111 		|| lzma_has_attribute(__always_inline__)
112 #	define lzma_always_inline inline __attribute__((__always_inline__))
113 #else
114 #	define lzma_always_inline inline
115 #endif
116 
117 // These allow helping the compiler in some often-executed branches, whose
118 // result is almost always the same.
119 #ifdef __GNUC__
120 #	define likely(expr) __builtin_expect(expr, true)
121 #	define unlikely(expr) __builtin_expect(expr, false)
122 #else
123 #	define likely(expr) (expr)
124 #	define unlikely(expr) (expr)
125 #endif
126 
127 
128 /// Size of temporary buffers needed in some filters
129 #define LZMA_BUFFER_SIZE 4096
130 
131 
132 /// Maximum number of worker threads within one multithreaded component.
133 /// The limit exists solely to make it simpler to prevent integer overflows
134 /// when allocating structures etc. This should be big enough for now...
135 /// the code won't scale anywhere close to this number anyway.
136 #define LZMA_THREADS_MAX 16384
137 
138 
139 /// Starting value for memory usage estimates. Instead of calculating size
140 /// of _every_ structure and taking into account malloc() overhead etc., we
141 /// add a base size to all memory usage estimates. It's not very accurate
142 /// but should be easily good enough.
143 #define LZMA_MEMUSAGE_BASE (UINT64_C(1) << 15)
144 
145 /// Start of internal Filter ID space. These IDs must never be used
146 /// in Streams.
147 #define LZMA_FILTER_RESERVED_START (LZMA_VLI_C(1) << 62)
148 
149 
150 /// Supported flags that can be passed to lzma_stream_decoder(),
151 /// lzma_auto_decoder(), or lzma_stream_decoder_mt().
152 #define LZMA_SUPPORTED_FLAGS \
153 	( LZMA_TELL_NO_CHECK \
154 	| LZMA_TELL_UNSUPPORTED_CHECK \
155 	| LZMA_TELL_ANY_CHECK \
156 	| LZMA_IGNORE_CHECK \
157 	| LZMA_CONCATENATED \
158 	| LZMA_FAIL_FAST )
159 
160 
161 /// Largest valid lzma_action value as unsigned integer.
162 #define LZMA_ACTION_MAX ((unsigned int)(LZMA_FULL_BARRIER))
163 
164 
165 /// Special return value (lzma_ret) to indicate that a timeout was reached
166 /// and lzma_code() must not return LZMA_BUF_ERROR. This is converted to
167 /// LZMA_OK in lzma_code().
168 #define LZMA_TIMED_OUT LZMA_RET_INTERNAL1
169 
170 /// Special return value (lzma_ret) for use in stream_decoder_mt.c to
171 /// indicate Index was detected instead of a Block Header.
172 #define LZMA_INDEX_DETECTED LZMA_RET_INTERNAL2
173 
174 
175 typedef struct lzma_next_coder_s lzma_next_coder;
176 
177 typedef struct lzma_filter_info_s lzma_filter_info;
178 
179 
180 /// Type of a function used to initialize a filter encoder or decoder
181 typedef lzma_ret (*lzma_init_function)(
182 		lzma_next_coder *next, const lzma_allocator *allocator,
183 		const lzma_filter_info *filters);
184 
185 /// Type of a function to do some kind of coding work (filters, Stream,
186 /// Block encoders/decoders etc.). Some special coders use don't use both
187 /// input and output buffers, but for simplicity they still use this same
188 /// function prototype.
189 typedef lzma_ret (*lzma_code_function)(
190 		void *coder, const lzma_allocator *allocator,
191 		const uint8_t *restrict in, size_t *restrict in_pos,
192 		size_t in_size, uint8_t *restrict out,
193 		size_t *restrict out_pos, size_t out_size,
194 		lzma_action action);
195 
196 /// Type of a function to free the memory allocated for the coder
197 typedef void (*lzma_end_function)(
198 		void *coder, const lzma_allocator *allocator);
199 
200 
201 /// Raw coder validates and converts an array of lzma_filter structures to
202 /// an array of lzma_filter_info structures. This array is used with
203 /// lzma_next_filter_init to initialize the filter chain.
204 struct lzma_filter_info_s {
205 	/// Filter ID. This can be used to share the same initiazation
206 	/// function *and* data structures with different Filter IDs
207 	/// (LZMA_FILTER_LZMA1EXT does it), and also by the encoder
208 	/// with lzma_filters_update() if filter chain is updated
209 	/// in the middle of a raw stream or Block (LZMA_SYNC_FLUSH).
210 	lzma_vli id;
211 
212 	/// Pointer to function used to initialize the filter.
213 	/// This is NULL to indicate end of array.
214 	lzma_init_function init;
215 
216 	/// Pointer to filter's options structure
217 	void *options;
218 };
219 
220 
221 /// Hold data and function pointers of the next filter in the chain.
222 struct lzma_next_coder_s {
223 	/// Pointer to coder-specific data
224 	void *coder;
225 
226 	/// Filter ID. This is LZMA_VLI_UNKNOWN when this structure doesn't
227 	/// point to a filter coder.
228 	lzma_vli id;
229 
230 	/// "Pointer" to init function. This is never called here.
231 	/// We need only to detect if we are initializing a coder
232 	/// that was allocated earlier. See lzma_next_coder_init and
233 	/// lzma_next_strm_init macros in this file.
234 	uintptr_t init;
235 
236 	/// Pointer to function to do the actual coding
237 	lzma_code_function code;
238 
239 	/// Pointer to function to free lzma_next_coder.coder. This can
240 	/// be NULL; in that case, lzma_free is called to free
241 	/// lzma_next_coder.coder.
242 	lzma_end_function end;
243 
244 	/// Pointer to a function to get progress information. If this is NULL,
245 	/// lzma_stream.total_in and .total_out are used instead.
246 	void (*get_progress)(void *coder,
247 			uint64_t *progress_in, uint64_t *progress_out);
248 
249 	/// Pointer to function to return the type of the integrity check.
250 	/// Most coders won't support this.
251 	lzma_check (*get_check)(const void *coder);
252 
253 	/// Pointer to function to get and/or change the memory usage limit.
254 	/// If new_memlimit == 0, the limit is not changed.
255 	lzma_ret (*memconfig)(void *coder, uint64_t *memusage,
256 			uint64_t *old_memlimit, uint64_t new_memlimit);
257 
258 	/// Update the filter-specific options or the whole filter chain
259 	/// in the encoder.
260 	lzma_ret (*update)(void *coder, const lzma_allocator *allocator,
261 			const lzma_filter *filters,
262 			const lzma_filter *reversed_filters);
263 
264 	/// Set how many bytes of output this coder may produce at maximum.
265 	/// On success LZMA_OK must be returned.
266 	/// If the filter chain as a whole cannot support this feature,
267 	/// this must return LZMA_OPTIONS_ERROR.
268 	/// If no input has been given to the coder and the requested limit
269 	/// is too small, this must return LZMA_BUF_ERROR. If input has been
270 	/// seen, LZMA_OK is allowed too.
271 	lzma_ret (*set_out_limit)(void *coder, uint64_t *uncomp_size,
272 			uint64_t out_limit);
273 };
274 
275 
276 /// Macro to initialize lzma_next_coder structure
277 #define LZMA_NEXT_CODER_INIT \
278 	(lzma_next_coder){ \
279 		.coder = NULL, \
280 		.init = (uintptr_t)(NULL), \
281 		.id = LZMA_VLI_UNKNOWN, \
282 		.code = NULL, \
283 		.end = NULL, \
284 		.get_progress = NULL, \
285 		.get_check = NULL, \
286 		.memconfig = NULL, \
287 		.update = NULL, \
288 		.set_out_limit = NULL, \
289 	}
290 
291 
292 /// Internal data for lzma_strm_init, lzma_code, and lzma_end. A pointer to
293 /// this is stored in lzma_stream.
294 struct lzma_internal_s {
295 	/// The actual coder that should do something useful
296 	lzma_next_coder next;
297 
298 	/// Track the state of the coder. This is used to validate arguments
299 	/// so that the actual coders can rely on e.g. that LZMA_SYNC_FLUSH
300 	/// is used on every call to lzma_code until next.code has returned
301 	/// LZMA_STREAM_END.
302 	enum {
303 		ISEQ_RUN,
304 		ISEQ_SYNC_FLUSH,
305 		ISEQ_FULL_FLUSH,
306 		ISEQ_FINISH,
307 		ISEQ_FULL_BARRIER,
308 		ISEQ_END,
309 		ISEQ_ERROR,
310 	} sequence;
311 
312 	/// A copy of lzma_stream avail_in. This is used to verify that the
313 	/// amount of input doesn't change once e.g. LZMA_FINISH has been
314 	/// used.
315 	size_t avail_in;
316 
317 	/// Indicates which lzma_action values are allowed by next.code.
318 	bool supported_actions[LZMA_ACTION_MAX + 1];
319 
320 	/// If true, lzma_code will return LZMA_BUF_ERROR if no progress was
321 	/// made (no input consumed and no output produced by next.code).
322 	bool allow_buf_error;
323 };
324 
325 
326 /// Allocates memory
327 lzma_attr_alloc_size(1)
328 extern void *lzma_alloc(size_t size, const lzma_allocator *allocator);
329 
330 /// Allocates memory and zeroes it (like calloc()). This can be faster
331 /// than lzma_alloc() + memzero() while being backward compatible with
332 /// custom allocators.
333 lzma_attr_alloc_size(1)
334 extern void *lzma_alloc_zero(size_t size, const lzma_allocator *allocator);
335 
336 /// Frees memory
337 extern void lzma_free(void *ptr, const lzma_allocator *allocator);
338 
339 
340 /// Allocates strm->internal if it is NULL, and initializes *strm and
341 /// strm->internal. This function is only called via lzma_next_strm_init macro.
342 extern lzma_ret lzma_strm_init(lzma_stream *strm);
343 
344 /// Initializes the next filter in the chain, if any. This takes care of
345 /// freeing the memory of previously initialized filter if it is different
346 /// than the filter being initialized now. This way the actual filter
347 /// initialization functions don't need to use lzma_next_coder_init macro.
348 extern lzma_ret lzma_next_filter_init(lzma_next_coder *next,
349 		const lzma_allocator *allocator,
350 		const lzma_filter_info *filters);
351 
352 /// Update the next filter in the chain, if any. This checks that
353 /// the application is not trying to change the Filter IDs.
354 extern lzma_ret lzma_next_filter_update(
355 		lzma_next_coder *next, const lzma_allocator *allocator,
356 		const lzma_filter *reversed_filters);
357 
358 /// Frees the memory allocated for next->coder either using next->end or,
359 /// if next->end is NULL, using lzma_free.
360 extern void lzma_next_end(lzma_next_coder *next,
361 		const lzma_allocator *allocator);
362 
363 
364 /// Copy as much data as possible from in[] to out[] and update *in_pos
365 /// and *out_pos accordingly. Returns the number of bytes copied.
366 extern size_t lzma_bufcpy(const uint8_t *restrict in, size_t *restrict in_pos,
367 		size_t in_size, uint8_t *restrict out,
368 		size_t *restrict out_pos, size_t out_size);
369 
370 
371 /// \brief      Return if expression doesn't evaluate to LZMA_OK
372 ///
373 /// There are several situations where we want to return immediately
374 /// with the value of expr if it isn't LZMA_OK. This macro shortens
375 /// the code a little.
376 #define return_if_error(expr) \
377 do { \
378 	const lzma_ret ret_ = (expr); \
379 	if (ret_ != LZMA_OK) \
380 		return ret_; \
381 } while (0)
382 
383 
384 /// If next isn't already initialized, free the previous coder. Then mark
385 /// that next is _possibly_ initialized for the coder using this macro.
386 /// "Possibly" means that if e.g. allocation of next->coder fails, the
387 /// structure isn't actually initialized for this coder, but leaving
388 /// next->init to func is still OK.
389 #define lzma_next_coder_init(func, next, allocator) \
390 do { \
391 	if ((uintptr_t)(func) != (next)->init) \
392 		lzma_next_end(next, allocator); \
393 	(next)->init = (uintptr_t)(func); \
394 } while (0)
395 
396 
397 /// Initializes lzma_strm and calls func() to initialize strm->internal->next.
398 /// (The function being called will use lzma_next_coder_init()). If
399 /// initialization fails, memory that wasn't freed by func() is freed
400 /// along strm->internal.
401 #define lzma_next_strm_init(func, strm, ...) \
402 do { \
403 	return_if_error(lzma_strm_init(strm)); \
404 	const lzma_ret ret_ = func(&(strm)->internal->next, \
405 			(strm)->allocator, __VA_ARGS__); \
406 	if (ret_ != LZMA_OK) { \
407 		lzma_end(strm); \
408 		return ret_; \
409 	} \
410 } while (0)
411 
412 #endif
413