1979a27acf62f29d17d61b396d255ac9380c10059Chih-Hung Hsieh/* Interfaces for libdw.
2   Copyright (C) 2002-2010, 2013, 2014 Red Hat, Inc.
3   This file is part of elfutils.
4
5   This file is free software; you can redistribute it and/or modify
6   it under the terms of either
7
8     * the GNU Lesser General Public License as published by the Free
9       Software Foundation; either version 3 of the License, or (at
10       your option) any later version
11
12   or
13
14     * the GNU General Public License as published by the Free
15       Software Foundation; either version 2 of the License, or (at
16       your option) any later version
17
18   or both in parallel, as here.
19
20   elfutils is distributed in the hope that it will be useful, but
21   WITHOUT ANY WARRANTY; without even the implied warranty of
22   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23   General Public License for more details.
24
25   You should have received copies of the GNU General Public License and
26   the GNU Lesser General Public License along with this program.  If
27   not, see <http://www.gnu.org/licenses/>.  */
28
29#ifndef _LIBDW_H
30#define _LIBDW_H	1
31
32#include <gelf.h>
33#include <stdbool.h>
34#include <stddef.h>
35#include <stdint.h>
36
37
38#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
39# define __nonnull_attribute__(...) __attribute__ ((__nonnull__ (__VA_ARGS__)))
40# define __deprecated_attribute__ __attribute__ ((__deprecated__))
41#else
42# define __nonnull_attribute__(args...)
43# define __deprecated_attribute__
44#endif
45
46
47#ifdef __GNUC_STDC_INLINE__
48# define __libdw_extern_inline extern __inline __attribute__ ((__gnu_inline__))
49#else
50# define __libdw_extern_inline extern __inline
51#endif
52
53
54/* Mode for the session.  */
55typedef enum
56  {
57    DWARF_C_READ,		/* Read .. */
58    DWARF_C_RDWR,		/* Read and write .. */
59    DWARF_C_WRITE,		/* Write .. */
60  }
61Dwarf_Cmd;
62
63
64/* Callback results.  */
65enum
66{
67  DWARF_CB_OK = 0,
68  DWARF_CB_ABORT
69};
70
71
72/* Error values.  */
73enum
74  {
75    DW_TAG_invalid = 0
76#define DW_TAG_invalid	DW_TAG_invalid
77  };
78
79
80/* Type for offset in DWARF file.  */
81typedef GElf_Off Dwarf_Off;
82
83/* Type for address in DWARF file.  */
84typedef GElf_Addr Dwarf_Addr;
85
86/* Integer types.  Big enough to hold any numeric value.  */
87typedef GElf_Xword Dwarf_Word;
88typedef GElf_Sxword Dwarf_Sword;
89/* For the times we know we do not need that much.  */
90typedef GElf_Half Dwarf_Half;
91
92
93/* DWARF abbreviation record.  */
94typedef struct Dwarf_Abbrev Dwarf_Abbrev;
95
96/* Returned to show the last DIE has be returned.  */
97#define DWARF_END_ABBREV ((Dwarf_Abbrev *) -1l)
98
99/* Source code line information for CU.  */
100typedef struct Dwarf_Lines_s Dwarf_Lines;
101
102/* One source code line information.  */
103typedef struct Dwarf_Line_s Dwarf_Line;
104
105/* Source file information.  */
106typedef struct Dwarf_Files_s Dwarf_Files;
107
108/* One address range record.  */
109typedef struct Dwarf_Arange_s Dwarf_Arange;
110
111/* Address ranges of a file.  */
112typedef struct Dwarf_Aranges_s Dwarf_Aranges;
113
114/* CU representation.  */
115struct Dwarf_CU;
116typedef struct Dwarf_CU Dwarf_CU;
117
118/* Macro information.  */
119typedef struct Dwarf_Macro_s Dwarf_Macro;
120
121/* Attribute representation.  */
122typedef struct
123{
124  unsigned int code;
125  unsigned int form;
126  unsigned char *valp;
127  struct Dwarf_CU *cu;
128} Dwarf_Attribute;
129
130
131/* Data block representation.  */
132typedef struct
133{
134  Dwarf_Word length;
135  unsigned char *data;
136} Dwarf_Block;
137
138
139/* DIE information.  */
140typedef struct
141{
142  /* The offset can be computed from the address.  */
143  void *addr;
144  struct Dwarf_CU *cu;
145  Dwarf_Abbrev *abbrev;
146  // XXX We'll see what other information will be needed.
147  long int padding__;
148} Dwarf_Die;
149
150/* Returned to show the last DIE has be returned.  */
151#define DWARF_END_DIE ((Dwarf_Die *) -1l)
152
153
154/* Global symbol information.  */
155typedef struct
156{
157  Dwarf_Off cu_offset;
158  Dwarf_Off die_offset;
159  const char *name;
160} Dwarf_Global;
161
162
163/* One operation in a DWARF location expression.
164   A location expression is an array of these.  */
165typedef struct
166{
167  uint8_t atom;			/* Operation */
168  Dwarf_Word number;		/* Operand */
169  Dwarf_Word number2;		/* Possible second operand */
170  Dwarf_Word offset;		/* Offset in location expression */
171} Dwarf_Op;
172
173
174/* This describes one Common Information Entry read from a CFI section.
175   Pointers here point into the DATA->d_buf block passed to dwarf_next_cfi.  */
176typedef struct
177{
178  Dwarf_Off CIE_id;	 /* Always DW_CIE_ID_64 in Dwarf_CIE structures.  */
179
180  /* Instruction stream describing initial state used by FDEs.  If
181     we did not understand the whole augmentation string and it did
182     not use 'z', then there might be more augmentation data here
183     (and in FDEs) before the actual instructions.  */
184  const uint8_t *initial_instructions;
185  const uint8_t *initial_instructions_end;
186
187  Dwarf_Word code_alignment_factor;
188  Dwarf_Sword data_alignment_factor;
189  Dwarf_Word return_address_register;
190
191  const char *augmentation;	/* Augmentation string.  */
192
193  /* Augmentation data, might be NULL.  The size is correct only if
194     we understood the augmentation string sufficiently.  */
195  const uint8_t *augmentation_data;
196  size_t augmentation_data_size;
197  size_t fde_augmentation_data_size;
198} Dwarf_CIE;
199
200/* This describes one Frame Description Entry read from a CFI section.
201   Pointers here point into the DATA->d_buf block passed to dwarf_next_cfi.  */
202typedef struct
203{
204  /* Section offset of CIE this FDE refers to.  This will never be
205     DW_CIE_ID_64 in an FDE.  If this value is DW_CIE_ID_64, this is
206     actually a Dwarf_CIE structure.  */
207  Dwarf_Off CIE_pointer;
208
209  /* We can't really decode anything further without looking up the CIE
210     and checking its augmentation string.  Here follows the encoded
211     initial_location and address_range, then any augmentation data,
212     then the instruction stream.  This FDE describes PC locations in
213     the byte range [initial_location, initial_location+address_range).
214     When the CIE augmentation string uses 'z', the augmentation data is
215     a DW_FORM_block (self-sized).  Otherwise, when we understand the
216     augmentation string completely, fde_augmentation_data_size gives
217     the number of bytes of augmentation data before the instructions.  */
218  const uint8_t *start;
219  const uint8_t *end;
220} Dwarf_FDE;
221
222/* Each entry in a CFI section is either a CIE described by Dwarf_CIE or
223   an FDE described by Dward_FDE.  Check CIE_id to see which you have.  */
224typedef union
225{
226  Dwarf_Off CIE_id;	 /* Always DW_CIE_ID_64 in Dwarf_CIE structures.  */
227  Dwarf_CIE cie;
228  Dwarf_FDE fde;
229} Dwarf_CFI_Entry;
230
231#define dwarf_cfi_cie_p(entry)	((entry)->cie.CIE_id == DW_CIE_ID_64)
232
233/* Opaque type representing a frame state described by CFI.  */
234typedef struct Dwarf_Frame_s Dwarf_Frame;
235
236/* Opaque type representing a CFI section found in a DWARF or ELF file.  */
237typedef struct Dwarf_CFI_s Dwarf_CFI;
238
239
240/* Handle for debug sessions.  */
241typedef struct Dwarf Dwarf;
242
243
244/* Out-Of-Memory handler.  */
245#if __GNUC__ < 4
246typedef void (*Dwarf_OOM) (void);
247#else
248typedef void (*__attribute__ ((noreturn)) Dwarf_OOM) (void);
249#endif
250
251
252#ifdef __cplusplus
253extern "C" {
254#endif
255
256/* Create a handle for a new debug session.  */
257extern Dwarf *dwarf_begin (int fildes, Dwarf_Cmd cmd);
258
259/* Create a handle for a new debug session for an ELF file.  */
260extern Dwarf *dwarf_begin_elf (Elf *elf, Dwarf_Cmd cmd, Elf_Scn *scngrp);
261
262/* Retrieve ELF descriptor used for DWARF access.  */
263extern Elf *dwarf_getelf (Dwarf *dwarf);
264
265/* Retieve DWARF descriptor used for a Dwarf_Die or Dwarf_Attribute.
266   A Dwarf_Die or a Dwarf_Attribute is associated with a particular
267   Dwarf_CU handle.  This function returns the DWARF descriptor for
268   that Dwarf_CU.  */
269extern Dwarf *dwarf_cu_getdwarf (Dwarf_CU *cu);
270
271/* Retrieves the DWARF descriptor for debugaltlink data.  Returns NULL
272   if no alternate debug data has been supplied.  */
273extern Dwarf *dwarf_getalt (Dwarf *main);
274
275/* Provides the data referenced by the .gnu_debugaltlink section.  The
276   caller should check that MAIN and ALT match (i.e., they have the
277   same build ID).  It is the responsibility of the caller to ensure
278   that the data referenced by ALT stays valid while it is used by
279   MAIN, until dwarf_setalt is called on MAIN with a different
280   descriptor, or dwarf_end.  */
281extern void dwarf_setalt (Dwarf *main, Dwarf *alt);
282
283/* Release debugging handling context.  */
284extern int dwarf_end (Dwarf *dwarf);
285
286
287/* Get the data block for the .debug_info section.  */
288extern Elf_Data *dwarf_getscn_info (Dwarf *dwarf);
289
290/* Read the header for the DWARF CU.  */
291extern int dwarf_nextcu (Dwarf *dwarf, Dwarf_Off off, Dwarf_Off *next_off,
292			 size_t *header_sizep, Dwarf_Off *abbrev_offsetp,
293			 uint8_t *address_sizep, uint8_t *offset_sizep)
294     __nonnull_attribute__ (3);
295
296/* Read the header of a DWARF CU or type unit.  If TYPE_SIGNATUREP is not
297   null, this reads a type unit from the .debug_types section; otherwise
298   this reads a CU from the .debug_info section.  */
299extern int dwarf_next_unit (Dwarf *dwarf, Dwarf_Off off, Dwarf_Off *next_off,
300			    size_t *header_sizep, Dwarf_Half *versionp,
301			    Dwarf_Off *abbrev_offsetp,
302			    uint8_t *address_sizep, uint8_t *offset_sizep,
303			    uint64_t *type_signaturep, Dwarf_Off *type_offsetp)
304     __nonnull_attribute__ (3);
305
306
307/* Decode one DWARF CFI entry (CIE or FDE) from the raw section data.
308   The E_IDENT from the originating ELF file indicates the address
309   size and byte order used in the CFI section contained in DATA;
310   EH_FRAME_P should be true for .eh_frame format and false for
311   .debug_frame format.  OFFSET is the byte position in the section
312   to start at; on return *NEXT_OFFSET is filled in with the byte
313   position immediately after this entry.
314
315   On success, returns 0 and fills in *ENTRY; use dwarf_cfi_cie_p to
316   see whether ENTRY->cie or ENTRY->fde is valid.
317
318   On errors, returns -1.  Some format errors will permit safely
319   skipping to the next CFI entry though the current one is unusable.
320   In that case, *NEXT_OFF will be updated before a -1 return.
321
322   If there are no more CFI entries left in the section,
323   returns 1 and sets *NEXT_OFFSET to (Dwarf_Off) -1.  */
324extern int dwarf_next_cfi (const unsigned char e_ident[],
325			   Elf_Data *data, bool eh_frame_p,
326			   Dwarf_Off offset, Dwarf_Off *next_offset,
327			   Dwarf_CFI_Entry *entry)
328  __nonnull_attribute__ (1, 2, 5, 6);
329
330/* Use the CFI in the DWARF .debug_frame section.
331   Returns NULL if there is no such section (not an error).
332   The pointer returned can be used until dwarf_end is called on DWARF,
333   and must not be passed to dwarf_cfi_end.
334   Calling this more than once returns the same pointer.  */
335extern Dwarf_CFI *dwarf_getcfi (Dwarf *dwarf);
336
337/* Use the CFI in the ELF file's exception-handling data.
338   Returns NULL if there is no such data.
339   The pointer returned can be used until elf_end is called on ELF,
340   and must be passed to dwarf_cfi_end before then.
341   Calling this more than once allocates independent data structures.  */
342extern Dwarf_CFI *dwarf_getcfi_elf (Elf *elf);
343
344/* Release resources allocated by dwarf_getcfi_elf.  */
345extern int dwarf_cfi_end (Dwarf_CFI *cache);
346
347
348/* Return DIE at given offset in .debug_info section.  */
349extern Dwarf_Die *dwarf_offdie (Dwarf *dbg, Dwarf_Off offset,
350				Dwarf_Die *result) __nonnull_attribute__ (3);
351
352/* Return DIE at given offset in .debug_types section.  */
353extern Dwarf_Die *dwarf_offdie_types (Dwarf *dbg, Dwarf_Off offset,
354				      Dwarf_Die *result)
355     __nonnull_attribute__ (3);
356
357/* Return offset of DIE.  */
358extern Dwarf_Off dwarf_dieoffset (Dwarf_Die *die);
359
360/* Return offset of DIE in CU.  */
361extern Dwarf_Off dwarf_cuoffset (Dwarf_Die *die);
362
363/* Return CU DIE containing given DIE.  */
364extern Dwarf_Die *dwarf_diecu (Dwarf_Die *die, Dwarf_Die *result,
365			       uint8_t *address_sizep, uint8_t *offset_sizep)
366     __nonnull_attribute__ (2);
367
368/* Return the CU DIE and the header info associated with a Dwarf_Die
369   or Dwarf_Attribute.  A Dwarf_Die or a Dwarf_Attribute is associated
370   with a particular Dwarf_CU handle.  This function returns the CU or
371   type unit DIE and header information for that Dwarf_CU.  The
372   returned DIE is either a compile_unit, partial_unit or type_unit.
373   If it is a type_unit, then the type signature and type offset are
374   also provided, otherwise type_offset will be set to zero.  See also
375   dwarf_diecu and dwarf_next_unit.  */
376extern Dwarf_Die *dwarf_cu_die (Dwarf_CU *cu, Dwarf_Die *result,
377				Dwarf_Half *versionp,
378				Dwarf_Off *abbrev_offsetp,
379				uint8_t *address_sizep,
380				uint8_t *offset_sizep,
381				uint64_t *type_signaturep,
382				Dwarf_Off *type_offsetp)
383     __nonnull_attribute__ (2);
384
385/* Return CU DIE containing given address.  */
386extern Dwarf_Die *dwarf_addrdie (Dwarf *dbg, Dwarf_Addr addr,
387				 Dwarf_Die *result) __nonnull_attribute__ (3);
388
389/* Return child of current DIE.  */
390extern int dwarf_child (Dwarf_Die *die, Dwarf_Die *result)
391     __nonnull_attribute__ (2);
392
393/* Locates the first sibling of DIE and places it in RESULT.
394   Returns 0 if a sibling was found, -1 if something went wrong.
395   Returns 1 if no sibling could be found and, if RESULT is not
396   the same as DIE, it sets RESULT->addr to the address of the
397   (non-sibling) DIE that follows this one, or NULL if this DIE
398   was the last one in the compilation unit.  */
399extern int dwarf_siblingof (Dwarf_Die *die, Dwarf_Die *result)
400     __nonnull_attribute__ (2);
401
402/* For type aliases and qualifier type DIEs follow the DW_AT_type
403   attribute (recursively) and return the underlying type Dwarf_Die.
404   Returns 0 when RESULT contains a Dwarf_Die (possibly equal to the
405   given DIE) that isn't a type alias or qualifier type.  Returns 1
406   when RESULT contains a type alias or qualifier Dwarf_Die that
407   couldn't be peeled further (it doesn't have a DW_TAG_type
408   attribute).  Returns -1 when an error occured.
409
410   The current DWARF specification defines one type alias tag
411   (DW_TAG_typedef) and three qualifier type tags (DW_TAG_const_type,
412   DW_TAG_volatile_type, DW_TAG_restrict_type).  DWARF5 defines one
413   other qualifier type tag (DW_TAG_atomic_type).  A future version of
414   this function might peel other alias or qualifier type tags if a
415   future DWARF version or GNU extension defines other type aliases or
416   qualifier type tags that don't modify or change the structural
417   layout of the underlying type.  */
418extern int dwarf_peel_type (Dwarf_Die *die, Dwarf_Die *result)
419    __nonnull_attribute__ (2);
420
421/* Check whether the DIE has children.  */
422extern int dwarf_haschildren (Dwarf_Die *die) __nonnull_attribute__ (1);
423
424/* Walks the attributes of DIE, starting at the one OFFSET bytes in,
425   calling the CALLBACK function for each one.  Stops if the callback
426   function ever returns a value other than DWARF_CB_OK and returns the
427   offset of the offending attribute.  If the end of the attributes
428   is reached 1 is returned.  If something goes wrong -1 is returned and
429   the dwarf error number is set.  */
430extern ptrdiff_t dwarf_getattrs (Dwarf_Die *die,
431				 int (*callback) (Dwarf_Attribute *, void *),
432				 void *arg, ptrdiff_t offset)
433     __nonnull_attribute__ (2);
434
435/* Return tag of given DIE.  */
436extern int dwarf_tag (Dwarf_Die *die) __nonnull_attribute__ (1);
437
438
439/* Return specific attribute of DIE.  */
440extern Dwarf_Attribute *dwarf_attr (Dwarf_Die *die, unsigned int search_name,
441				    Dwarf_Attribute *result)
442     __nonnull_attribute__ (3);
443
444/* Check whether given DIE has specific attribute.  */
445extern int dwarf_hasattr (Dwarf_Die *die, unsigned int search_name);
446
447/* These are the same as dwarf_attr and dwarf_hasattr, respectively,
448   but they resolve an indirect attribute through DW_AT_abstract_origin.  */
449extern Dwarf_Attribute *dwarf_attr_integrate (Dwarf_Die *die,
450					      unsigned int search_name,
451					      Dwarf_Attribute *result)
452     __nonnull_attribute__ (3);
453extern int dwarf_hasattr_integrate (Dwarf_Die *die, unsigned int search_name);
454
455
456
457
458/* Check whether given attribute has specific form.  */
459extern int dwarf_hasform (Dwarf_Attribute *attr, unsigned int search_form);
460
461/* Return attribute code of given attribute.  */
462extern unsigned int dwarf_whatattr (Dwarf_Attribute *attr);
463
464/* Return form code of given attribute.  */
465extern unsigned int dwarf_whatform (Dwarf_Attribute *attr);
466
467
468/* Return string associated with given attribute.  */
469extern const char *dwarf_formstring (Dwarf_Attribute *attrp);
470
471/* Return unsigned constant represented by attribute.  */
472extern int dwarf_formudata (Dwarf_Attribute *attr, Dwarf_Word *return_uval)
473     __nonnull_attribute__ (2);
474
475/* Return signed constant represented by attribute.  */
476extern int dwarf_formsdata (Dwarf_Attribute *attr, Dwarf_Sword *return_uval)
477     __nonnull_attribute__ (2);
478
479/* Return address represented by attribute.  */
480extern int dwarf_formaddr (Dwarf_Attribute *attr, Dwarf_Addr *return_addr)
481     __nonnull_attribute__ (2);
482
483/* This function is deprecated.  Always use dwarf_formref_die instead.
484   Return reference offset represented by attribute.  */
485extern int dwarf_formref (Dwarf_Attribute *attr, Dwarf_Off *return_offset)
486     __nonnull_attribute__ (2) __deprecated_attribute__;
487
488/* Look up the DIE in a reference-form attribute.  */
489extern Dwarf_Die *dwarf_formref_die (Dwarf_Attribute *attr, Dwarf_Die *die_mem)
490     __nonnull_attribute__ (2);
491
492/* Return block represented by attribute.  */
493extern int dwarf_formblock (Dwarf_Attribute *attr, Dwarf_Block *return_block)
494     __nonnull_attribute__ (2);
495
496/* Return flag represented by attribute.  */
497extern int dwarf_formflag (Dwarf_Attribute *attr, bool *return_bool)
498     __nonnull_attribute__ (2);
499
500
501/* Simplified attribute value access functions.  */
502
503/* Return string in name attribute of DIE.  */
504extern const char *dwarf_diename (Dwarf_Die *die);
505
506/* Return high PC attribute of DIE.  */
507extern int dwarf_highpc (Dwarf_Die *die, Dwarf_Addr *return_addr)
508     __nonnull_attribute__ (2);
509
510/* Return low PC attribute of DIE.  */
511extern int dwarf_lowpc (Dwarf_Die *die, Dwarf_Addr *return_addr)
512     __nonnull_attribute__ (2);
513
514/* Return entry_pc or low_pc attribute of DIE.  */
515extern int dwarf_entrypc (Dwarf_Die *die, Dwarf_Addr *return_addr)
516     __nonnull_attribute__ (2);
517
518/* Return 1 if DIE's lowpc/highpc or ranges attributes match the PC address,
519   0 if not, or -1 for errors.  */
520extern int dwarf_haspc (Dwarf_Die *die, Dwarf_Addr pc);
521
522/* Enumerate the PC address ranges covered by this DIE, covering all
523   addresses where dwarf_haspc returns true.  In the first call OFFSET
524   should be zero and *BASEP need not be initialized.  Returns -1 for
525   errors, zero when there are no more address ranges to report, or a
526   nonzero OFFSET value to pass to the next call.  Each subsequent call
527   must preserve *BASEP from the prior call.  Successful calls fill in
528   *STARTP and *ENDP with a contiguous address range.  */
529extern ptrdiff_t dwarf_ranges (Dwarf_Die *die,
530			       ptrdiff_t offset, Dwarf_Addr *basep,
531			       Dwarf_Addr *startp, Dwarf_Addr *endp);
532
533
534/* Return byte size attribute of DIE.  */
535extern int dwarf_bytesize (Dwarf_Die *die);
536
537/* Return bit size attribute of DIE.  */
538extern int dwarf_bitsize (Dwarf_Die *die);
539
540/* Return bit offset attribute of DIE.  */
541extern int dwarf_bitoffset (Dwarf_Die *die);
542
543/* Return array order attribute of DIE.  */
544extern int dwarf_arrayorder (Dwarf_Die *die);
545
546/* Return source language attribute of DIE.  */
547extern int dwarf_srclang (Dwarf_Die *die);
548
549
550/* Get abbreviation at given offset for given DIE.  */
551extern Dwarf_Abbrev *dwarf_getabbrev (Dwarf_Die *die, Dwarf_Off offset,
552				      size_t *lengthp);
553
554/* Get abbreviation at given offset in .debug_abbrev section.  */
555extern int dwarf_offabbrev (Dwarf *dbg, Dwarf_Off offset, size_t *lengthp,
556			    Dwarf_Abbrev *abbrevp)
557     __nonnull_attribute__ (4);
558
559/* Get abbreviation code.  */
560extern unsigned int dwarf_getabbrevcode (Dwarf_Abbrev *abbrev);
561
562/* Get abbreviation tag.  */
563extern unsigned int dwarf_getabbrevtag (Dwarf_Abbrev *abbrev);
564
565/* Return true if abbreviation is children flag set.  */
566extern int dwarf_abbrevhaschildren (Dwarf_Abbrev *abbrev);
567
568/* Get number of attributes of abbreviation.  */
569extern int dwarf_getattrcnt (Dwarf_Abbrev *abbrev, size_t *attrcntp)
570     __nonnull_attribute__ (2);
571
572/* Get specific attribute of abbreviation.  */
573extern int dwarf_getabbrevattr (Dwarf_Abbrev *abbrev, size_t idx,
574				unsigned int *namep, unsigned int *formp,
575				Dwarf_Off *offset);
576
577
578/* Get string from-debug_str section.  */
579extern const char *dwarf_getstring (Dwarf *dbg, Dwarf_Off offset,
580				    size_t *lenp);
581
582
583/* Get public symbol information.  */
584extern ptrdiff_t dwarf_getpubnames (Dwarf *dbg,
585				    int (*callback) (Dwarf *, Dwarf_Global *,
586						     void *),
587				    void *arg, ptrdiff_t offset)
588     __nonnull_attribute__ (2);
589
590
591/* Get source file information for CU.  */
592extern int dwarf_getsrclines (Dwarf_Die *cudie, Dwarf_Lines **lines,
593			      size_t *nlines) __nonnull_attribute__ (2, 3);
594
595/* Return one of the source lines of the CU.  */
596extern Dwarf_Line *dwarf_onesrcline (Dwarf_Lines *lines, size_t idx);
597
598/* Get the file source files used in the CU.  */
599extern int dwarf_getsrcfiles (Dwarf_Die *cudie, Dwarf_Files **files,
600			      size_t *nfiles)
601     __nonnull_attribute__ (2);
602
603
604/* Get source for address in CU.  */
605extern Dwarf_Line *dwarf_getsrc_die (Dwarf_Die *cudie, Dwarf_Addr addr);
606
607/* Get source for file and line number.  */
608extern int dwarf_getsrc_file (Dwarf *dbg, const char *fname, int line, int col,
609			      Dwarf_Line ***srcsp, size_t *nsrcs)
610     __nonnull_attribute__ (2, 5, 6);
611
612
613/* Return line address.  */
614extern int dwarf_lineaddr (Dwarf_Line *line, Dwarf_Addr *addrp);
615
616/* Return line VLIW operation index.  */
617extern int dwarf_lineop_index (Dwarf_Line *line, unsigned int *op_indexp);
618
619/* Return line number.  */
620extern int dwarf_lineno (Dwarf_Line *line, int *linep)
621     __nonnull_attribute__ (2);
622
623/* Return column in line.  */
624extern int dwarf_linecol (Dwarf_Line *line, int *colp)
625     __nonnull_attribute__ (2);
626
627/* Return true if record is for beginning of a statement.  */
628extern int dwarf_linebeginstatement (Dwarf_Line *line, bool *flagp)
629     __nonnull_attribute__ (2);
630
631/* Return true if record is for end of sequence.  */
632extern int dwarf_lineendsequence (Dwarf_Line *line, bool *flagp)
633     __nonnull_attribute__ (2);
634
635/* Return true if record is for beginning of a basic block.  */
636extern int dwarf_lineblock (Dwarf_Line *line, bool *flagp)
637     __nonnull_attribute__ (2);
638
639/* Return true if record is for end of prologue.  */
640extern int dwarf_lineprologueend (Dwarf_Line *line, bool *flagp)
641     __nonnull_attribute__ (2);
642
643/* Return true if record is for beginning of epilogue.  */
644extern int dwarf_lineepiloguebegin (Dwarf_Line *line, bool *flagp)
645     __nonnull_attribute__ (2);
646
647/* Return instruction-set architecture in this record.  */
648extern int dwarf_lineisa (Dwarf_Line *line, unsigned int *isap)
649     __nonnull_attribute__ (2);
650
651/* Return code path discriminator in this record.  */
652extern int dwarf_linediscriminator (Dwarf_Line *line, unsigned int *discp)
653     __nonnull_attribute__ (2);
654
655
656/* Find line information for address.  */
657extern const char *dwarf_linesrc (Dwarf_Line *line,
658				  Dwarf_Word *mtime, Dwarf_Word *length);
659
660/* Return file information.  */
661extern const char *dwarf_filesrc (Dwarf_Files *file, size_t idx,
662				  Dwarf_Word *mtime, Dwarf_Word *length);
663
664/* Return the directory list used in the file information extracted.
665   (*RESULT)[0] is the CU's DW_AT_comp_dir value, and may be null.
666   (*RESULT)[0..*NDIRS-1] are the compile-time include directory path
667   encoded by the compiler.  */
668extern int dwarf_getsrcdirs (Dwarf_Files *files,
669			     const char *const **result, size_t *ndirs)
670  __nonnull_attribute__ (2, 3);
671
672
673/* Return location expression, decoded as a list of operations.  */
674extern int dwarf_getlocation (Dwarf_Attribute *attr, Dwarf_Op **expr,
675			      size_t *exprlen) __nonnull_attribute__ (2, 3);
676
677/* Return location expressions.  If the attribute uses a location list,
678   ADDRESS selects the relevant location expressions from the list.
679   There can be multiple matches, resulting in multiple expressions to
680   return.  EXPRS and EXPRLENS are parallel arrays of NLOCS slots to
681   fill in.  Returns the number of locations filled in, or -1 for
682   errors.  If EXPRS is a null pointer, stores nothing and returns the
683   total number of locations.  A return value of zero means that the
684   location list indicated no value is accessible.  */
685extern int dwarf_getlocation_addr (Dwarf_Attribute *attr, Dwarf_Addr address,
686				   Dwarf_Op **exprs, size_t *exprlens,
687				   size_t nlocs);
688
689/* Enumerate the locations ranges and descriptions covered by the
690   given attribute.  In the first call OFFSET should be zero and
691   *BASEP need not be initialized.  Returns -1 for errors, zero when
692   there are no more locations to report, or a nonzero OFFSET
693   value to pass to the next call.  Each subsequent call must preserve
694   *BASEP from the prior call.  Successful calls fill in *STARTP and
695   *ENDP with a contiguous address range and *EXPR with a pointer to
696   an array of operations with length *EXPRLEN.  If the attribute
697   describes a single location description and not a location list the
698   first call (with OFFSET zero) will return the location description
699   in *EXPR with *STARTP set to zero and *ENDP set to minus one.  */
700extern ptrdiff_t dwarf_getlocations (Dwarf_Attribute *attr,
701				     ptrdiff_t offset, Dwarf_Addr *basep,
702				     Dwarf_Addr *startp, Dwarf_Addr *endp,
703				     Dwarf_Op **expr, size_t *exprlen);
704
705/* Return the block associated with a DW_OP_implicit_value operation.
706   The OP pointer must point into an expression that dwarf_getlocation
707   or dwarf_getlocation_addr has returned given the same ATTR.  */
708extern int dwarf_getlocation_implicit_value (Dwarf_Attribute *attr,
709					     const Dwarf_Op *op,
710					     Dwarf_Block *return_block)
711  __nonnull_attribute__ (2, 3);
712
713/* Return the attribute indicated by a DW_OP_GNU_implicit_pointer operation.
714   The OP pointer must point into an expression that dwarf_getlocation
715   or dwarf_getlocation_addr has returned given the same ATTR.
716   The result is the DW_AT_location or DW_AT_const_value attribute
717   of the OP->number DIE.  */
718extern int dwarf_getlocation_implicit_pointer (Dwarf_Attribute *attr,
719					       const Dwarf_Op *op,
720					       Dwarf_Attribute *result)
721  __nonnull_attribute__ (2, 3);
722
723/* Return the DIE associated with an operation such as
724   DW_OP_GNU_implicit_pointer, DW_OP_GNU_parameter_ref, DW_OP_GNU_convert,
725   DW_OP_GNU_reinterpret, DW_OP_GNU_const_type, DW_OP_GNU_regval_type or
726   DW_OP_GNU_deref_type.  The OP pointer must point into an expression that
727   dwarf_getlocation or dwarf_getlocation_addr has returned given the same
728   ATTR.  The RESULT is a DIE that expresses a type or value needed by the
729   given OP.  */
730extern int dwarf_getlocation_die (Dwarf_Attribute *attr,
731				  const Dwarf_Op *op,
732				  Dwarf_Die *result)
733  __nonnull_attribute__ (2, 3);
734
735/* Return the attribute expressing a value associated with an operation such
736   as DW_OP_implicit_value, DW_OP_GNU_entry_value or DW_OP_GNU_const_type.
737   The OP pointer must point into an expression that dwarf_getlocation
738   or dwarf_getlocation_addr has returned given the same ATTR.
739   The RESULT is a value expressed by an attribute such as DW_AT_location
740   or DW_AT_const_value.  */
741extern int dwarf_getlocation_attr (Dwarf_Attribute *attr,
742				   const Dwarf_Op *op,
743				   Dwarf_Attribute *result)
744  __nonnull_attribute__ (2, 3);
745
746
747/* Compute the byte-size of a type DIE according to DWARF rules.
748   For most types, this is just DW_AT_byte_size.
749   For DW_TAG_array_type it can apply much more complex rules.  */
750extern int dwarf_aggregate_size (Dwarf_Die *die, Dwarf_Word *size);
751
752
753/* Return scope DIEs containing PC address.
754   Sets *SCOPES to a malloc'd array of Dwarf_Die structures,
755   and returns the number of elements in the array.
756   (*SCOPES)[0] is the DIE for the innermost scope containing PC,
757   (*SCOPES)[1] is the DIE for the scope containing that scope, and so on.
758   Returns -1 for errors or 0 if no scopes match PC.  */
759extern int dwarf_getscopes (Dwarf_Die *cudie, Dwarf_Addr pc,
760			    Dwarf_Die **scopes);
761
762/* Return scope DIEs containing the given DIE.
763   Sets *SCOPES to a malloc'd array of Dwarf_Die structures,
764   and returns the number of elements in the array.
765   (*SCOPES)[0] is a copy of DIE.
766   (*SCOPES)[1] is the DIE for the scope containing that scope, and so on.
767   Returns -1 for errors or 0 if DIE is not found in any scope entry.  */
768extern int dwarf_getscopes_die (Dwarf_Die *die, Dwarf_Die **scopes);
769
770
771/* Search SCOPES[0..NSCOPES-1] for a variable called NAME.
772   Ignore the first SKIP_SHADOWS scopes that match the name.
773   If MATCH_FILE is not null, accept only declaration in that source file;
774   if MATCH_LINENO or MATCH_LINECOL are also nonzero, accept only declaration
775   at that line and column.
776
777   If successful, fill in *RESULT with the DIE of the variable found,
778   and return N where SCOPES[N] is the scope defining the variable.
779   Return -1 for errors or -2 for no matching variable found.  */
780extern int dwarf_getscopevar (Dwarf_Die *scopes, int nscopes,
781			      const char *name, int skip_shadows,
782			      const char *match_file,
783			      int match_lineno, int match_linecol,
784			      Dwarf_Die *result);
785
786
787
788/* Return list address ranges.  */
789extern int dwarf_getaranges (Dwarf *dbg, Dwarf_Aranges **aranges,
790			     size_t *naranges)
791     __nonnull_attribute__ (2);
792
793/* Return one of the address range entries.  */
794extern Dwarf_Arange *dwarf_onearange (Dwarf_Aranges *aranges, size_t idx);
795
796/* Return information in address range record.  */
797extern int dwarf_getarangeinfo (Dwarf_Arange *arange, Dwarf_Addr *addrp,
798				Dwarf_Word *lengthp, Dwarf_Off *offsetp);
799
800/* Get address range which includes given address.  */
801extern Dwarf_Arange *dwarf_getarange_addr (Dwarf_Aranges *aranges,
802					   Dwarf_Addr addr);
803
804
805
806/* Get functions in CUDIE.  The given callback will be called for all
807   defining DW_TAG_subprograms in the CU DIE tree.  If the callback
808   returns DWARF_CB_ABORT the return value can be used as offset argument
809   to resume the function to find all remaining functions (this is not
810   really recommended, since it needs to rewalk the CU DIE tree first till
811   that offset is found again).  If the callback returns DWARF_CB_OK
812   dwarf_getfuncs will not return but keep calling the callback for each
813   function DIE it finds.  Pass zero for offset on the first call to walk
814   the full CU DIE tree.  If no more functions can be found and the callback
815   returned DWARF_CB_OK then the function returns zero.  */
816extern ptrdiff_t dwarf_getfuncs (Dwarf_Die *cudie,
817				 int (*callback) (Dwarf_Die *, void *),
818				 void *arg, ptrdiff_t offset);
819
820
821/* Return file name containing definition of the given declaration.  */
822extern const char *dwarf_decl_file (Dwarf_Die *decl);
823
824/* Get line number of beginning of given declaration.  */
825extern int dwarf_decl_line (Dwarf_Die *decl, int *linep)
826     __nonnull_attribute__ (2);
827
828/* Get column number of beginning of given declaration.  */
829extern int dwarf_decl_column (Dwarf_Die *decl, int *colp)
830     __nonnull_attribute__ (2);
831
832
833/* Return nonzero if given function is an abstract inline definition.  */
834extern int dwarf_func_inline (Dwarf_Die *func);
835
836/* Find each concrete inlined instance of the abstract inline definition.  */
837extern int dwarf_func_inline_instances (Dwarf_Die *func,
838					int (*callback) (Dwarf_Die *, void *),
839					void *arg);
840
841
842/* Find the appropriate PC location or locations for function entry
843   breakpoints for the given DW_TAG_subprogram DIE.  Returns -1 for errors.
844   On success, returns the number of breakpoint locations (never zero)
845   and sets *BKPTS to a malloc'd vector of addresses.  */
846extern int dwarf_entry_breakpoints (Dwarf_Die *die, Dwarf_Addr **bkpts);
847
848
849/* Iterate through the macro unit referenced by CUDIE and call
850   CALLBACK for each macro information entry.  To start the iteration,
851   one would pass DWARF_GETMACROS_START for TOKEN.
852
853   The iteration continues while CALLBACK returns DWARF_CB_OK.  If the
854   callback returns DWARF_CB_ABORT, the iteration stops and a
855   continuation token is returned, which can be used to restart the
856   iteration at the point where it ended.  Returns -1 for errors or 0
857   if there are no more macro entries.
858
859   Note that the Dwarf_Macro pointer passed to the callback is only
860   valid for the duration of the callback invocation.
861
862   For backward compatibility, a token of 0 is accepted for starting
863   the iteration as well, but in that case this interface will refuse
864   to serve opcode 0xff from .debug_macro sections.  Such opcode would
865   be considered invalid and would cause dwarf_getmacros to return
866   with error.  */
867#define DWARF_GETMACROS_START PTRDIFF_MIN
868extern ptrdiff_t dwarf_getmacros (Dwarf_Die *cudie,
869				  int (*callback) (Dwarf_Macro *, void *),
870				  void *arg, ptrdiff_t token)
871     __nonnull_attribute__ (2);
872
873/* This is similar in operation to dwarf_getmacros, but selects the
874   unit to iterate through by offset instead of by CU, and always
875   iterates .debug_macro.  This can be used for handling
876   DW_MACRO_GNU_transparent_include's or similar opcodes.
877
878   TOKEN value of DWARF_GETMACROS_START can be used to start the
879   iteration.
880
881   It is not appropriate to obtain macro unit offset by hand from a CU
882   DIE and then request iteration through this interface.  The reason
883   for this is that if a dwarf_macro_getsrcfiles is later called,
884   there would be no way to figure out what DW_AT_comp_dir was present
885   on the CU DIE, and file names referenced in either the macro unit
886   itself, or the .debug_line unit that it references, might be wrong.
887   Use dwarf_getmacros.  */
888extern ptrdiff_t dwarf_getmacros_off (Dwarf *dbg, Dwarf_Off macoff,
889				      int (*callback) (Dwarf_Macro *, void *),
890				      void *arg, ptrdiff_t token)
891  __nonnull_attribute__ (3);
892
893/* Get the source files used by the macro entry.  You shouldn't assume
894   that Dwarf_Files references will remain valid after MACRO becomes
895   invalid.  (Which is to say it's only valid within the
896   dwarf_getmacros* callback.)  Returns 0 for success or a negative
897   value in case of an error.  */
898extern int dwarf_macro_getsrcfiles (Dwarf *dbg, Dwarf_Macro *macro,
899				    Dwarf_Files **files, size_t *nfiles)
900  __nonnull_attribute__ (2, 3, 4);
901
902/* Return macro opcode.  That's a constant that can be either from
903   DW_MACINFO_* domain or DW_MACRO_GNU_* domain.  The two domains have
904   compatible values, so it's OK to use either of them for
905   comparisons.  The only differences is 0xff, which could be either
906   DW_MACINFO_vendor_ext or a vendor-defined DW_MACRO_* constant.  One
907   would need to look if the CU DIE which the iteration was requested
908   for has attribute DW_AT_macro_info, or either of DW_AT_GNU_macros
909   or DW_AT_macros to differentiate the two interpretations.  */
910extern int dwarf_macro_opcode (Dwarf_Macro *macro, unsigned int *opcodep)
911     __nonnull_attribute__ (2);
912
913/* Get number of parameters of MACRO and store it to *PARAMCNTP.  */
914extern int dwarf_macro_getparamcnt (Dwarf_Macro *macro, size_t *paramcntp);
915
916/* Get IDX-th parameter of MACRO (numbered from zero), and stores it
917   to *ATTRIBUTE.  Returns 0 on success or -1 for errors.
918
919   After a successful call, you can query ATTRIBUTE by dwarf_whatform
920   to determine which of the dwarf_formX calls to make to get actual
921   value out of ATTRIBUTE.  Note that calling dwarf_whatattr is not
922   meaningful for pseudo-attributes formed this way.  */
923extern int dwarf_macro_param (Dwarf_Macro *macro, size_t idx,
924			      Dwarf_Attribute *attribute);
925
926/* Return macro parameter with index 0.  This will return -1 if the
927   parameter is not an integral value.  Use dwarf_macro_param for more
928   general access.  */
929extern int dwarf_macro_param1 (Dwarf_Macro *macro, Dwarf_Word *paramp)
930     __nonnull_attribute__ (2);
931
932/* Return macro parameter with index 1.  This will return -1 if the
933   parameter is not an integral or string value.  Use
934   dwarf_macro_param for more general access.  */
935extern int dwarf_macro_param2 (Dwarf_Macro *macro, Dwarf_Word *paramp,
936			       const char **strp);
937
938/* Compute what's known about a call frame when the PC is at ADDRESS.
939   Returns 0 for success or -1 for errors.
940   On success, *FRAME is a malloc'd pointer.  */
941extern int dwarf_cfi_addrframe (Dwarf_CFI *cache,
942				Dwarf_Addr address, Dwarf_Frame **frame)
943  __nonnull_attribute__ (3);
944
945/* Return the DWARF register number used in FRAME to denote
946   the return address in FRAME's caller frame.  The remaining
947   arguments can be non-null to fill in more information.
948
949   Fill [*START, *END) with the PC range to which FRAME's information applies.
950   Fill in *SIGNALP to indicate whether this is a signal-handling frame.
951   If true, this is the implicit call frame that calls a signal handler.
952   This frame's "caller" is actually the interrupted state, not a call;
953   its return address is an exact PC, not a PC after a call instruction.  */
954extern int dwarf_frame_info (Dwarf_Frame *frame,
955			     Dwarf_Addr *start, Dwarf_Addr *end, bool *signalp);
956
957/* Return a DWARF expression that yields the Canonical Frame Address at
958   this frame state.  Returns -1 for errors, or zero for success, with
959   *NOPS set to the number of operations stored at *OPS.  That pointer
960   can be used only as long as FRAME is alive and unchanged.  *NOPS is
961   zero if the CFA cannot be determined here.  Note that if nonempty,
962   *OPS is a DWARF expression, not a location description--append
963   DW_OP_stack_value to a get a location description for the CFA.  */
964extern int dwarf_frame_cfa (Dwarf_Frame *frame, Dwarf_Op **ops, size_t *nops)
965  __nonnull_attribute__ (2);
966
967/* Deliver a DWARF location description that yields the location or
968   value of DWARF register number REGNO in the state described by FRAME.
969
970   Returns -1 for errors or zero for success, setting *NOPS to the
971   number of operations in the array stored at *OPS.  Note the last
972   operation is DW_OP_stack_value if there is no mutable location but
973   only a computable value.
974
975   *NOPS zero with *OPS set to OPS_MEM means CFI says the caller's
976   REGNO is "undefined", i.e. it's call-clobbered and cannot be recovered.
977
978   *NOPS zero with *OPS set to a null pointer means CFI says the
979   caller's REGNO is "same_value", i.e. this frame did not change it;
980   ask the caller frame where to find it.
981
982   For common simple expressions *OPS is OPS_MEM.  For arbitrary DWARF
983   expressions in the CFI, *OPS is an internal pointer that can be used as
984   long as the Dwarf_CFI used to create FRAME remains alive.  */
985extern int dwarf_frame_register (Dwarf_Frame *frame, int regno,
986				 Dwarf_Op ops_mem[3],
987				 Dwarf_Op **ops, size_t *nops)
988  __nonnull_attribute__ (3, 4, 5);
989
990
991/* Return error code of last failing function call.  This value is kept
992   separately for each thread.  */
993extern int dwarf_errno (void);
994
995/* Return error string for ERROR.  If ERROR is zero, return error string
996   for most recent error or NULL is none occurred.  If ERROR is -1 the
997   behaviour is similar to the last case except that not NULL but a legal
998   string is returned.  */
999extern const char *dwarf_errmsg (int err);
1000
1001
1002/* Register new Out-Of-Memory handler.  The old handler is returned.  */
1003extern Dwarf_OOM dwarf_new_oom_handler (Dwarf *dbg, Dwarf_OOM handler);
1004
1005
1006/* Inline optimizations.  */
1007#ifdef __OPTIMIZE__
1008/* Return attribute code of given attribute.  */
1009__libdw_extern_inline unsigned int
1010dwarf_whatattr (Dwarf_Attribute *attr)
1011{
1012  return attr == NULL ? 0 : attr->code;
1013}
1014
1015/* Return attribute code of given attribute.  */
1016__libdw_extern_inline unsigned int
1017dwarf_whatform (Dwarf_Attribute *attr)
1018{
1019  return attr == NULL ? 0 : attr->form;
1020}
1021#endif	/* Optimize.  */
1022
1023#ifdef __cplusplus
1024}
1025#endif
1026
1027#endif	/* libdw.h */
1028