gdb/dwarf2loc.h - gdb

Data types defined

Macros defined

Source code

  1. /* DWARF 2 location expression support for GDB.

  3.    Copyright (C) 2003-2015 Free Software Foundation, Inc.

  5.    This file is part of GDB.

  7.    This program is free software; you can redistribute it and/or modify
  8.    it under the terms of the GNU General Public License as published by
  9.    the Free Software Foundation; either version 3 of the License, or
  10.    (at your option) any later version.

  12.    This program is distributed in the hope that it will be useful,
  13.    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14.    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15.    GNU General Public License for more details.

  17.    You should have received a copy of the GNU General Public License
  18.    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

  20. #if !defined (DWARF2LOC_H)
  21. ‌#define DWARF2LOC_H

  23. #include "dwarf2expr.h"

  25. struct symbol_computed_ops;
  26. struct objfile;
  27. struct dwarf2_per_cu_data;
  28. struct dwarf2_loclist_baton;
  29. struct agent_expr;
  30. struct axs_value;

  32. /* This header is private to the DWARF-2 reader.  It is shared between
  33.    dwarf2read.c and dwarf2loc.c.  */

  35. /* `set debug entry-values' setting.  */
  36. extern unsigned int entry_values_debug;

  38. /* Return the OBJFILE associated with the compilation unit CU.  If CU
  39.    came from a separate debuginfo file, then the master objfile is
  40.    returned.  */
  41. struct objfile *dwarf2_per_cu_objfile (struct dwarf2_per_cu_data *cu);

  43. /* Return the address size given in the compilation unit header for CU.  */
  44. int dwarf2_per_cu_addr_size (struct dwarf2_per_cu_data *cu);

  46. /* Return the DW_FORM_ref_addr size given in the compilation unit header for
  47.    CU.  */
  48. int dwarf2_per_cu_ref_addr_size (struct dwarf2_per_cu_data *cu);

  50. /* Return the offset size given in the compilation unit header for CU.  */
  51. int dwarf2_per_cu_offset_size (struct dwarf2_per_cu_data *cu);

  53. /* Return the text offset of the CU.  The returned offset comes from
  54.    this CU's objfile.  If this objfile came from a separate debuginfo
  55.    file, then the offset may be different from the corresponding
  56.    offset in the parent objfile.  */
  57. CORE_ADDR dwarf2_per_cu_text_offset (struct dwarf2_per_cu_data *cu);

  59. /* Find a particular location expression from a location list.  */
  60. const gdb_byte *dwarf2_find_location_expression
  61.   (struct dwarf2_loclist_baton *baton,
  62.    size_t *locexpr_length,
  63.    CORE_ADDR pc);

  65. struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_sect_off
  66.   (sect_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu,
  67.    CORE_ADDR (*get_frame_pc) (void *baton),
  68.    void *baton);

  70. struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_cu_off
  71.   (cu_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu,
  72.    CORE_ADDR (*get_frame_pc) (void *baton),
  73.    void *baton);

  75. extern const gdb_byte *dwarf2_fetch_constant_bytes (sect_offset,
  76.                                                     struct dwarf2_per_cu_data *,
  77.                                                     struct obstack *,
  78.                                                     LONGEST *);

  80. struct type *dwarf2_get_die_type (cu_offset die_offset,
  81.                                   struct dwarf2_per_cu_data *per_cu);

  83. /* Find the frame base information for FRAMEFUNC at PC.  START is an
  84.    out parameter which is set to point to the DWARF expression to
  85.    compute.  LENGTH is an out parameter which is set to the length of
  86.    the DWARF expression.  This throws an exception on error or if an
  87.    expression is not found; the returned length will never be
  88.    zero.  */

  90. extern void func_get_frame_base_dwarf_block (struct symbol *framefunc,
  91.                                              CORE_ADDR pc,
  92.                                              const gdb_byte **start,
  93.                                              size_t *length);

  95. /* Evaluate a location description, starting at DATA and with length
  96.    SIZE, to find the current location of variable of TYPE in the context
  97.    of FRAME.  */

  99. struct value *dwarf2_evaluate_loc_desc (struct type *type,
  100.                                         struct frame_info *frame,
  101.                                         const gdb_byte *data,
  102.                                         size_t size,
  103.                                         struct dwarf2_per_cu_data *per_cu);

  105. /* Converts a dynamic property into a static one.  ADDRESS is the address
  106.    of the object currently being evaluated and might be nedded.
  107.    Returns 1 if PROP could be converted and the static value is passed back
  108.    into VALUE, otherwise returns 0.  */

  110. int dwarf2_evaluate_property (const struct dynamic_prop *prop,
  111.                               CORE_ADDR address,
  112.                               CORE_ADDR *value);

  114. /* A helper for the compiler interface that compiles a single dynamic
  115.    property to C code.

  117.    STREAM is where the C code is to be written.
  118.    RESULT_NAME is the name of the generated variable.
  119.    GDBARCH is the architecture to use.
  120.    REGISTERS_USED is a bit-vector that is filled to note which
  121.    registers are required by the generated expression.
  122.    PROP is the property for which code is generated.
  123.    ADDRESS is the address at which the property is considered to be
  124.    evaluated.
  125.    SYM the originating symbol, used for error reporting.  */

  127. void dwarf2_compile_property_to_c (struct ui_file *stream,
  128.                                    const char *result_name,
  129.                                    struct gdbarch *gdbarch,
  130.                                    unsigned char *registers_used,
  131.                                    const struct dynamic_prop *prop,
  132.                                    CORE_ADDR address,
  133.                                    struct symbol *sym);

  135. CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu,
  136.                                   unsigned int addr_index);

  138. /* The symbol location baton types used by the DWARF-2 reader (i.e.
  139.    SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol).  "struct
  140.    dwarf2_locexpr_baton" is for a symbol with a single location
  141.    expression; "struct dwarf2_loclist_baton" is for a symbol with a
  142.    location list.  */

  144. ‌struct dwarf2_locexpr_baton
  145. {
  146.   /* Pointer to the start of the location expression.  Valid only if SIZE is
  147.      not zero.  */
  148.   const gdb_byte *data;

  150.   /* Length of the location expression.  For optimized out expressions it is
  151.      zero.  */
  152.   size_t size;

  154.   /* The compilation unit containing the symbol whose location
  155.      we're computing.  */
  156.   struct dwarf2_per_cu_data *per_cu;
  157. };

  159. ‌struct dwarf2_loclist_baton
  160. {
  161.   /* The initial base address for the location list, based on the compilation
  162.      unit.  */
  163.   CORE_ADDR base_address;

  165.   /* Pointer to the start of the location list.  */
  166.   const gdb_byte *data;

  168.   /* Length of the location list.  */
  169.   size_t size;

  171.   /* The compilation unit containing the symbol whose location
  172.      we're computing.  */
  173.   struct dwarf2_per_cu_data *per_cu;

  175.   /* Non-zero if the location list lives in .debug_loc.dwo.
  176.      The format of entries in this section are different.  */
  177.   unsigned char from_dwo;
  178. };

  180. /* A dynamic property is either expressed as a single location expression
  181.    or a location list.  If the property is an indirection, pointing to
  182.    another die, keep track of the targeted type in REFERENCED_TYPE.  */

  184. ‌struct dwarf2_property_baton
  185. {
  186.   /* If the property is an indirection, we need to evaluate the location
  187.      LOCEXPR or LOCLIST in the context of the type REFERENCED_TYPE.
  188.      If NULL, the location is the actual value of the property.  */
  189.   struct type *referenced_type;
  190.   union
  191.   {
  192.     /* Location expression.  */
  193.     struct dwarf2_locexpr_baton locexpr;

  195.     /* Location list to be evaluated in the context of REFERENCED_TYPE.  */
  196.     struct dwarf2_loclist_baton loclist;
  197.   };
  198. };

  200. extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
  201. extern const struct symbol_computed_ops dwarf2_loclist_funcs;

  203. extern const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs;
  204. extern const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs;

  206. /* Compile a DWARF location expression to an agent expression.

  208.    EXPR is the agent expression we are building.
  209.    LOC is the agent value we modify.
  210.    ARCH is the architecture.
  211.    ADDR_SIZE is the size of addresses, in bytes.
  212.    OP_PTR is the start of the location expression.
  213.    OP_END is one past the last byte of the location expression.

  215.    This will throw an exception for various kinds of errors -- for
  216.    example, if the expression cannot be compiled, or if the expression
  217.    is invalid.  */

  219. extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
  220.                                        struct axs_value *loc,
  221.                                        struct gdbarch *arch,
  222.                                        unsigned int addr_size,
  223.                                        const gdb_byte *op_ptr,
  224.                                        const gdb_byte *op_end,
  225.                                        struct dwarf2_per_cu_data *per_cu);

  227. /* Determined tail calls for constructing virtual tail call frames.  */

  229. ‌struct call_site_chain
  230.   {
  231.     /* Initially CALLERS == CALLEES == LENGTH.  For partially ambiguous result
  232.        CALLERS + CALLEES < LENGTH.  */
  233.     int callers, callees, length;

  235.     /* Variably sized array with LENGTH elements.  Later [0..CALLERS-1] contain
  236.        top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
  237.        (GDB "next") sites.  One is interested primarily in the PC field.  */
  238.     struct call_site *call_site[1];
  239.   };

  241. struct call_site_stuff;
  242. extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
  243.                                                      CORE_ADDR caller_pc,
  244.                                                      CORE_ADDR callee_pc);

  246. /* A helper function to convert a DWARF register to an arch register.
  247.    ARCH is the architecture.
  248.    DWARF_REG is the register.
  249.    This will throw an exception if the DWARF register cannot be
  250.    translated to an architecture register.  */

  252. extern int dwarf2_reg_to_regnum_or_error (struct gdbarch *arch, int dwarf_reg);

  254. #endif /* dwarf2loc.h */