X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fdwarf2expr.h;h=3d7ca002c5e7c6e9a2f1a67d7deeaacba245e269;hb=0f8288ae82bf5bdb33d46d7447cd3132393a1bd2;hp=cc5c4f322b457849c8d31e1577b746f8298073b0;hpb=197e01b6dcd118b70ed3621b62b2ff3fa929d50f;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/dwarf2expr.h b/gdb/dwarf2expr.h index cc5c4f322b..3d7ca002c5 100644 --- a/gdb/dwarf2expr.h +++ b/gdb/dwarf2expr.h @@ -1,6 +1,6 @@ /* DWARF 2 Expression Evaluator. - Copyright (C) 2001, 2002, 2003, 2005 Free Software Foundation, Inc. + Copyright (C) 2001-2016 Free Software Foundation, Inc. Contributed by Daniel Berlin . @@ -8,7 +8,7 @@ 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 2 of the License, or + 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, @@ -17,30 +17,29 @@ 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, write to the Free Software - Foundation, Inc., 51 Franklin Street, Fifth Floor, - Boston, MA 02110-1301, USA. */ + along with this program. If not, see . */ #if !defined (DWARF2EXPR_H) #define DWARF2EXPR_H -/* The expression evaluator works with a dwarf_expr_context, describing - its current state and its callbacks. */ -struct dwarf_expr_context -{ - /* The stack of values, allocated with xmalloc. */ - CORE_ADDR *stack; +#include "leb128.h" +#include "gdbtypes.h" - /* The number of values currently pushed on the stack, and the - number of elements allocated to the stack. */ - int stack_len, stack_allocated; +struct dwarf_expr_context; - /* An opaque argument provided by the caller, which will be passed - to all of the callback functions. */ - void *baton; +/* Virtual method table for struct dwarf_expr_context below. */ + +struct dwarf_expr_context_funcs +{ + /* Return the value of register number REGNUM (a DWARF register number), + read as an address. */ + CORE_ADDR (*read_addr_from_reg) (void *baton, int regnum); + + /* Return a value of type TYPE, stored in register number REGNUM + of the frame associated to the given BATON. - /* Return the value of register number REGNUM. */ - CORE_ADDR (*read_reg) (void *baton, int regnum); + REGNUM is a DWARF register number. */ + struct value *(*get_reg_value) (void *baton, struct type *type, int regnum); /* Read LENGTH bytes at ADDR into BUF. */ void (*read_mem) (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t length); @@ -48,42 +47,142 @@ struct dwarf_expr_context /* Return the location expression for the frame base attribute, in START and LENGTH. The result must be live until the current expression evaluation is complete. */ - void (*get_frame_base) (void *baton, gdb_byte **start, size_t *length); + void (*get_frame_base) (void *baton, const gdb_byte **start, size_t *length); + + /* Return the CFA for the frame. */ + CORE_ADDR (*get_frame_cfa) (void *baton); + + /* Return the PC for the frame. */ + CORE_ADDR (*get_frame_pc) (void *baton); /* Return the thread-local storage address for DW_OP_GNU_push_tls_address. */ CORE_ADDR (*get_tls_address) (void *baton, CORE_ADDR offset); -#if 0 - /* Not yet implemented. */ - - /* Return the location expression for the dwarf expression - subroutine in the die at OFFSET in the current compilation unit. - The result must be live until the current expression evaluation - is complete. */ - unsigned char *(*get_subr) (void *baton, off_t offset, size_t *length); + /* Execute DW_AT_location expression for the DWARF expression subroutine in + the DIE at DIE_OFFSET in the CU from CTX. Do not touch STACK while it + being passed to and returned from the called DWARF subroutine. */ + void (*dwarf_call) (struct dwarf_expr_context *ctx, cu_offset die_offset); + + /* Return the base type given by the indicated DIE. This can throw + an exception if the DIE is invalid or does not represent a base + type. If can also be NULL in the special case where the + callbacks are not performing evaluation, and thus it is + meaningful to substitute a stub type of the correct size. */ + struct type *(*get_base_type) (struct dwarf_expr_context *ctx, cu_offset die); + + /* Push on DWARF stack an entry evaluated for DW_TAG_GNU_call_site's + parameter matching KIND and KIND_U at the caller of specified BATON. + If DEREF_SIZE is not -1 then use DW_AT_GNU_call_site_data_value instead of + DW_AT_GNU_call_site_value. */ + void (*push_dwarf_reg_entry_value) (struct dwarf_expr_context *ctx, + enum call_site_parameter_kind kind, + union call_site_parameter_u kind_u, + int deref_size); + + /* Return the address indexed by DW_OP_GNU_addr_index. + This can throw an exception if the index is out of range. */ + CORE_ADDR (*get_addr_index) (void *baton, unsigned int index); /* Return the `object address' for DW_OP_push_object_address. */ CORE_ADDR (*get_object_address) (void *baton); -#endif +}; + +/* The location of a value. */ +enum dwarf_value_location +{ + /* The piece is in memory. + The value on the dwarf stack is its address. */ + DWARF_VALUE_MEMORY, + + /* The piece is in a register. + The value on the dwarf stack is the register number. */ + DWARF_VALUE_REGISTER, + + /* The piece is on the dwarf stack. */ + DWARF_VALUE_STACK, + + /* The piece is a literal. */ + DWARF_VALUE_LITERAL, + + /* The piece was optimized out. */ + DWARF_VALUE_OPTIMIZED_OUT, + + /* The piece is an implicit pointer. */ + DWARF_VALUE_IMPLICIT_POINTER +}; + +/* The dwarf expression stack. */ + +struct dwarf_stack_value +{ + struct value *value; + + /* Non-zero if the piece is in memory and is known to be + on the program's stack. It is always ok to set this to zero. + This is used, for example, to optimize memory access from the target. + It can vastly speed up backtraces on long latency connections when + "set stack-cache on". */ + int in_stack_memory; +}; + +/* The expression evaluator works with a dwarf_expr_context, describing + its current state and its callbacks. */ +struct dwarf_expr_context +{ + /* The stack of values, allocated with xmalloc. */ + struct dwarf_stack_value *stack; + + /* The number of values currently pushed on the stack, and the + number of elements allocated to the stack. */ + int stack_len, stack_allocated; + + /* Target architecture to use for address operations. */ + struct gdbarch *gdbarch; + + /* Target address size in bytes. */ + int addr_size; + + /* DW_FORM_ref_addr size in bytes. If -1 DWARF is executed from a frame + context and operations depending on DW_FORM_ref_addr are not allowed. */ + int ref_addr_size; + + /* Offset used to relocate DW_OP_addr and DW_OP_GNU_addr_index arguments. */ + CORE_ADDR offset; + + /* An opaque argument provided by the caller, which will be passed + to all of the callback functions. */ + void *baton; + + /* Callback functions. */ + const struct dwarf_expr_context_funcs *funcs; /* The current depth of dwarf expression recursion, via DW_OP_call*, DW_OP_fbreg, DW_OP_push_object_address, etc., and the maximum depth we'll tolerate before raising an error. */ int recursion_depth, max_recursion_depth; - /* Non-zero if the result is in a register. The register number - will be on the expression stack. */ - int in_reg; + /* Location of the value. */ + enum dwarf_value_location location; + + /* For DWARF_VALUE_LITERAL, the current literal value's length and + data. For DWARF_VALUE_IMPLICIT_POINTER, LEN is the offset of the + target DIE of sect_offset kind. */ + ULONGEST len; + const gdb_byte *data; + + /* Initialization status of variable: Non-zero if variable has been + initialized; zero otherwise. */ + int initialized; /* An array of pieces. PIECES points to its first element; NUM_PIECES is its length. Each time DW_OP_piece is executed, we add a new element to the end of this array, recording the current top of the stack, the - current in_reg flag, and the size given as the operand to - DW_OP_piece. We then pop the top value from the stack, clear the - in_reg flag, and resume evaluation. + current location, and the size given as the operand to + DW_OP_piece. We then pop the top value from the stack, reset the + location, and resume evaluation. The Dwarf spec doesn't say whether DW_OP_piece pops the top value from the stack. We do, ensuring that clients of this interface @@ -94,45 +193,153 @@ struct dwarf_expr_context If an expression never uses DW_OP_piece, num_pieces will be zero. (It would be nice to present these cases as expressions yielding - a single piece, with in_reg clear, so that callers need not - distinguish between the no-DW_OP_piece and one-DW_OP_piece cases. - But expressions with no DW_OP_piece operations have no value to - place in a piece's 'size' field; the size comes from the - surrounding data. So the two cases need to be handled - separately.) */ + a single piece, so that callers need not distinguish between the + no-DW_OP_piece and one-DW_OP_piece cases. But expressions with + no DW_OP_piece operations have no value to place in a piece's + 'size' field; the size comes from the surrounding data. So the + two cases need to be handled separately.) */ int num_pieces; struct dwarf_expr_piece *pieces; }; -/* A piece of an object, as recorded by DW_OP_piece. */ +/* A piece of an object, as recorded by DW_OP_piece or DW_OP_bit_piece. */ struct dwarf_expr_piece { - /* If IN_REG is zero, then the piece is in memory, and VALUE is its address. - If IN_REG is non-zero, then the piece is in a register, and VALUE - is the register number. */ - int in_reg; - - /* This piece's address or register number. */ - CORE_ADDR value; - - /* The length of the piece, in bytes. */ + enum dwarf_value_location location; + + union + { + struct + { + /* This piece's address, for DWARF_VALUE_MEMORY pieces. */ + CORE_ADDR addr; + /* Non-zero if the piece is known to be in memory and on + the program's stack. */ + int in_stack_memory; + } mem; + + /* The piece's register number, for DWARF_VALUE_REGISTER pieces. */ + int regno; + + /* The piece's literal value, for DWARF_VALUE_STACK pieces. */ + struct value *value; + + struct + { + /* A pointer to the data making up this piece, + for DWARF_VALUE_LITERAL pieces. */ + const gdb_byte *data; + /* The length of the available data. */ + ULONGEST length; + } literal; + + /* Used for DWARF_VALUE_IMPLICIT_POINTER. */ + struct + { + /* The referent DIE from DW_OP_GNU_implicit_pointer. */ + sect_offset die; + /* The byte offset into the resulting data. */ + LONGEST offset; + } ptr; + } v; + + /* The length of the piece, in bits. */ ULONGEST size; + /* The piece offset, in bits. */ + ULONGEST offset; }; struct dwarf_expr_context *new_dwarf_expr_context (void); void free_dwarf_expr_context (struct dwarf_expr_context *ctx); +struct cleanup * + make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx); -void dwarf_expr_push (struct dwarf_expr_context *ctx, CORE_ADDR value); -void dwarf_expr_pop (struct dwarf_expr_context *ctx); -void dwarf_expr_eval (struct dwarf_expr_context *ctx, unsigned char *addr, +void dwarf_expr_push_address (struct dwarf_expr_context *ctx, + CORE_ADDR value, + int in_stack_memory); +void dwarf_expr_eval (struct dwarf_expr_context *ctx, const gdb_byte *addr, size_t len); -CORE_ADDR dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n); +struct value *dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n); +CORE_ADDR dwarf_expr_fetch_address (struct dwarf_expr_context *ctx, int n); +int dwarf_expr_fetch_in_stack_memory (struct dwarf_expr_context *ctx, int n); + +void dwarf_expr_require_composition (const gdb_byte *, const gdb_byte *, + const char *); + +/* Stub dwarf_expr_context_funcs implementations. */ + +void ctx_no_get_frame_base (void *baton, const gdb_byte **start, + size_t *length); +CORE_ADDR ctx_no_get_frame_cfa (void *baton); +CORE_ADDR ctx_no_get_frame_pc (void *baton); +CORE_ADDR ctx_no_get_tls_address (void *baton, CORE_ADDR offset); +void ctx_no_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset); +struct type *ctx_no_get_base_type (struct dwarf_expr_context *ctx, + cu_offset die); +void ctx_no_push_dwarf_reg_entry_value (struct dwarf_expr_context *ctx, + enum call_site_parameter_kind kind, + union call_site_parameter_u kind_u, + int deref_size); +CORE_ADDR ctx_no_get_addr_index (void *baton, unsigned int index); + +int dwarf_block_to_dwarf_reg (const gdb_byte *buf, const gdb_byte *buf_end); + +int dwarf_block_to_dwarf_reg_deref (const gdb_byte *buf, + const gdb_byte *buf_end, + CORE_ADDR *deref_size_return); + +int dwarf_block_to_fb_offset (const gdb_byte *buf, const gdb_byte *buf_end, + CORE_ADDR *fb_offset_return); + +int dwarf_block_to_sp_offset (struct gdbarch *gdbarch, const gdb_byte *buf, + const gdb_byte *buf_end, + CORE_ADDR *sp_offset_return); + +/* Wrappers around the leb128 reader routines to simplify them for our + purposes. */ + +static inline const gdb_byte * +gdb_read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end, + uint64_t *r) +{ + size_t bytes_read = read_uleb128_to_uint64 (buf, buf_end, r); + + if (bytes_read == 0) + return NULL; + return buf + bytes_read; +} + +static inline const gdb_byte * +gdb_read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end, + int64_t *r) +{ + size_t bytes_read = read_sleb128_to_int64 (buf, buf_end, r); + + if (bytes_read == 0) + return NULL; + return buf + bytes_read; +} + +static inline const gdb_byte * +gdb_skip_leb128 (const gdb_byte *buf, const gdb_byte *buf_end) +{ + size_t bytes_read = skip_leb128 (buf, buf_end); + + if (bytes_read == 0) + return NULL; + return buf + bytes_read; +} + +extern const gdb_byte *safe_read_uleb128 (const gdb_byte *buf, + const gdb_byte *buf_end, + uint64_t *r); +extern const gdb_byte *safe_read_sleb128 (const gdb_byte *buf, + const gdb_byte *buf_end, + int64_t *r); -gdb_byte *read_uleb128 (gdb_byte *buf, gdb_byte *buf_end, ULONGEST * r); -gdb_byte *read_sleb128 (gdb_byte *buf, gdb_byte *buf_end, LONGEST * r); -CORE_ADDR dwarf2_read_address (gdb_byte *buf, gdb_byte *buf_end, - int *bytes_read); +extern const gdb_byte *safe_skip_leb128 (const gdb_byte *buf, + const gdb_byte *buf_end); #endif /* dwarf2expr.h */