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Diffstat (limited to 'gdb/dwarf2/loc.h')
| -rw-r--r-- | gdb/dwarf2/loc.h | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h new file mode 100644 index 0000000..a49a990 --- /dev/null +++ b/gdb/dwarf2/loc.h @@ -0,0 +1,324 @@ +/* DWARF 2 location expression support for GDB. + + Copyright (C) 2003-2020 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#if !defined (DWARF2LOC_H) +#define DWARF2LOC_H + +#include "dwarf2/expr.h" + +struct symbol_computed_ops; +struct objfile; +struct dwarf2_per_cu_data; +struct dwarf2_loclist_baton; +struct agent_expr; +struct axs_value; + +/* This header is private to the DWARF-2 reader. It is shared between + dwarf2read.c and dwarf2loc.c. */ + +/* `set debug entry-values' setting. */ +extern unsigned int entry_values_debug; + +/* Return the OBJFILE associated with the compilation unit CU. If CU + came from a separate debuginfo file, then the master objfile is + returned. */ +struct objfile *dwarf2_per_cu_objfile (struct dwarf2_per_cu_data *cu); + +/* Return the address size given in the compilation unit header for CU. */ +int dwarf2_per_cu_addr_size (struct dwarf2_per_cu_data *cu); + +/* Return the DW_FORM_ref_addr size given in the compilation unit header for + CU. */ +int dwarf2_per_cu_ref_addr_size (struct dwarf2_per_cu_data *cu); + +/* Return the offset size given in the compilation unit header for CU. */ +int dwarf2_per_cu_offset_size (struct dwarf2_per_cu_data *cu); + +/* Return the text offset of the CU. The returned offset comes from + this CU's objfile. If this objfile came from a separate debuginfo + file, then the offset may be different from the corresponding + offset in the parent objfile. */ +CORE_ADDR dwarf2_per_cu_text_offset (struct dwarf2_per_cu_data *cu); + +short dwarf2_version (struct dwarf2_per_cu_data *per_cu); + +/* Find a particular location expression from a location list. */ +const gdb_byte *dwarf2_find_location_expression + (struct dwarf2_loclist_baton *baton, + size_t *locexpr_length, + CORE_ADDR pc); + +struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_sect_off + (sect_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu, + CORE_ADDR (*get_frame_pc) (void *baton), + void *baton, bool resolve_abstract_p = false); + +struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_cu_off + (cu_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu, + CORE_ADDR (*get_frame_pc) (void *baton), + void *baton); + +extern const gdb_byte *dwarf2_fetch_constant_bytes (sect_offset, + struct dwarf2_per_cu_data *, + struct obstack *, + LONGEST *); + +struct type *dwarf2_fetch_die_type_sect_off (sect_offset, + struct dwarf2_per_cu_data *); + +struct type *dwarf2_get_die_type (cu_offset die_offset, + struct dwarf2_per_cu_data *per_cu); + +/* Find the frame base information for FRAMEFUNC at PC. START is an + out parameter which is set to point to the DWARF expression to + compute. LENGTH is an out parameter which is set to the length of + the DWARF expression. This throws an exception on error or if an + expression is not found; the returned length will never be + zero. */ + +extern void func_get_frame_base_dwarf_block (struct symbol *framefunc, + CORE_ADDR pc, + const gdb_byte **start, + size_t *length); + +/* Evaluate a location description, starting at DATA and with length + SIZE, to find the current location of variable of TYPE in the context + of FRAME. */ + +struct value *dwarf2_evaluate_loc_desc (struct type *type, + struct frame_info *frame, + const gdb_byte *data, + size_t size, + struct dwarf2_per_cu_data *per_cu); + +/* A chain of addresses that might be needed to resolve a dynamic + property. */ + +struct property_addr_info +{ + /* The type of the object whose dynamic properties, if any, are + being resolved. */ + struct type *type; + + /* If not NULL, a buffer containing the object's value. */ + const gdb_byte *valaddr; + + /* The address of that object. */ + CORE_ADDR addr; + + /* If not NULL, a pointer to the info for the object containing + the object described by this node. */ + struct property_addr_info *next; +}; + +/* Converts a dynamic property into a static one. FRAME is the frame in which + the property is evaluated; if NULL, the selected frame (if any) is used + instead. + + ADDR_STACK is the stack of addresses that might be needed to evaluate the + property. When evaluating a property that is not related to a type, it can + be NULL. + + Returns true if PROP could be converted and the static value is passed + back into VALUE, otherwise returns false. */ + +bool dwarf2_evaluate_property (const struct dynamic_prop *prop, + struct frame_info *frame, + struct property_addr_info *addr_stack, + CORE_ADDR *value); + +/* A helper for the compiler interface that compiles a single dynamic + property to C code. + + STREAM is where the C code is to be written. + RESULT_NAME is the name of the generated variable. + GDBARCH is the architecture to use. + REGISTERS_USED is a bit-vector that is filled to note which + registers are required by the generated expression. + PROP is the property for which code is generated. + ADDRESS is the address at which the property is considered to be + evaluated. + SYM the originating symbol, used for error reporting. */ + +void dwarf2_compile_property_to_c (string_file *stream, + const char *result_name, + struct gdbarch *gdbarch, + unsigned char *registers_used, + const struct dynamic_prop *prop, + CORE_ADDR address, + struct symbol *sym); + +CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu, + unsigned int addr_index); + +/* The symbol location baton types used by the DWARF-2 reader (i.e. + SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol). "struct + dwarf2_locexpr_baton" is for a symbol with a single location + expression; "struct dwarf2_loclist_baton" is for a symbol with a + location list. */ + +struct dwarf2_locexpr_baton +{ + /* Pointer to the start of the location expression. Valid only if SIZE is + not zero. */ + const gdb_byte *data; + + /* Length of the location expression. For optimized out expressions it is + zero. */ + size_t size; + + /* When true this location expression is a reference and actually + describes the address at which the value of the attribute can be + found. When false the expression provides the value of the attribute + directly. */ + bool is_reference; + + /* The compilation unit containing the symbol whose location + we're computing. */ + struct dwarf2_per_cu_data *per_cu; +}; + +struct dwarf2_loclist_baton +{ + /* The initial base address for the location list, based on the compilation + unit. */ + CORE_ADDR base_address; + + /* Pointer to the start of the location list. */ + const gdb_byte *data; + + /* Length of the location list. */ + size_t size; + + /* The compilation unit containing the symbol whose location + we're computing. */ + struct dwarf2_per_cu_data *per_cu; + + /* Non-zero if the location list lives in .debug_loc.dwo. + The format of entries in this section are different. */ + unsigned char from_dwo; +}; + +/* The baton used when a dynamic property is an offset to a parent + type. This can be used, for instance, then the bound of an array + inside a record is determined by the value of another field inside + that record. */ + +struct dwarf2_offset_baton +{ + /* The offset from the parent type where the value of the property + is stored. In the example provided above, this would be the offset + of the field being used as the array bound. */ + LONGEST offset; + + /* The type of the object whose property is dynamic. In the example + provided above, this would the array's index type. */ + struct type *type; +}; + +/* A dynamic property is either expressed as a single location expression + or a location list. If the property is an indirection, pointing to + another die, keep track of the targeted type in PROPERTY_TYPE. + Alternatively, if the property location gives the property value + directly then it will have PROPERTY_TYPE. */ + +struct dwarf2_property_baton +{ + /* If the property is an indirection, we need to evaluate the location + in the context of the type PROPERTY_TYPE. If the property is supplied + by value then it will be of PROPERTY_TYPE. This field should never be + NULL. */ + struct type *property_type; + union + { + /* Location expression either evaluated in the context of + PROPERTY_TYPE, or a value of type PROPERTY_TYPE. */ + struct dwarf2_locexpr_baton locexpr; + + /* Location list to be evaluated in the context of PROPERTY_TYPE. */ + struct dwarf2_loclist_baton loclist; + + /* The location is an offset to PROPERTY_TYPE. */ + struct dwarf2_offset_baton offset_info; + }; +}; + +extern const struct symbol_computed_ops dwarf2_locexpr_funcs; +extern const struct symbol_computed_ops dwarf2_loclist_funcs; + +extern const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs; +extern const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs; + +/* Compile a DWARF location expression to an agent expression. + + EXPR is the agent expression we are building. + LOC is the agent value we modify. + ARCH is the architecture. + ADDR_SIZE is the size of addresses, in bytes. + OP_PTR is the start of the location expression. + OP_END is one past the last byte of the location expression. + + This will throw an exception for various kinds of errors -- for + example, if the expression cannot be compiled, or if the expression + is invalid. */ + +extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr, + struct axs_value *loc, + unsigned int addr_size, + const gdb_byte *op_ptr, + const gdb_byte *op_end, + struct dwarf2_per_cu_data *per_cu); + +/* Determined tail calls for constructing virtual tail call frames. */ + +struct call_site_chain + { + /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result + CALLERS + CALLEES < LENGTH. */ + int callers, callees, length; + + /* Variably sized array with LENGTH elements. Later [0..CALLERS-1] contain + top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom + (GDB "next") sites. One is interested primarily in the PC field. */ + struct call_site *call_site[1]; + }; + +struct call_site_stuff; +extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch, + CORE_ADDR caller_pc, + CORE_ADDR callee_pc); + +/* A helper function to convert a DWARF register to an arch register. + ARCH is the architecture. + DWARF_REG is the register. + If DWARF_REG is bad then a complaint is issued and -1 is returned. + Note: Some targets get this wrong. */ + +extern int dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg); + +/* A wrapper on dwarf_reg_to_regnum to throw an exception if the + DWARF register cannot be translated to an architecture register. + This takes a ULONGEST instead of an int because some callers actually have + a ULONGEST. Negative values passed as ints will still be flagged as + invalid. */ + +extern int dwarf_reg_to_regnum_or_error (struct gdbarch *arch, + ULONGEST dwarf_reg); + +#endif /* dwarf2loc.h */ |