/* DWARF 2 Expression Evaluator.
- Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009, 2010, 2011
- Free Software Foundation, Inc.
+ Copyright (C) 2001-2020 Free Software Foundation, Inc.
Contributed by Daniel Berlin <dan@dberlin.org>.
#if !defined (DWARF2EXPR_H)
#define DWARF2EXPR_H
+#include "leb128.h"
+#include "gdbtypes.h"
+
/* The location of a value. */
enum dwarf_value_location
{
DWARF_VALUE_IMPLICIT_POINTER
};
+/* A piece of an object, as recorded by DW_OP_piece or DW_OP_bit_piece. */
+struct dwarf_expr_piece
+{
+ 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. */
+ bool 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_implicit_pointer. */
+ sect_offset die_sect_off;
+ /* 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;
+};
+
/* The dwarf expression stack. */
struct dwarf_stack_value
{
+ dwarf_stack_value (struct value *value_, int in_stack_memory_)
+ : value (value_), in_stack_memory (in_stack_memory_)
+ {}
+
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;
+ /* True 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". */
+ bool 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;
+ dwarf_expr_context ();
+ virtual ~dwarf_expr_context () = default;
+
+ void push_address (CORE_ADDR value, bool in_stack_memory);
+ void eval (const gdb_byte *addr, size_t len);
+ struct value *fetch (int n);
+ CORE_ADDR fetch_address (int n);
+ bool fetch_in_stack_memory (int n);
- /* The number of values currently pushed on the stack, and the
- number of elements allocated to the stack. */
- int stack_len, stack_allocated;
+ /* The stack of values. */
+ std::vector<dwarf_stack_value> stack;
/* Target architecture to use for address operations. */
struct gdbarch *gdbarch;
/* Target address size in bytes. */
int addr_size;
- /* Offset used to relocate DW_OP_addr argument. */
- CORE_ADDR offset;
-
- /* An opaque argument provided by the caller, which will be passed
- to all of the callback functions. */
- void *baton;
+ /* 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;
- /* Return the value of register number REGNUM. */
- CORE_ADDR (*read_reg) (void *baton, int regnum);
-
- /* Read LENGTH bytes at ADDR into BUF. */
- void (*read_mem) (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t length);
-
- /* 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, 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);
-
- /* 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, size_t 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, size_t die);
-
-#if 0
- /* Not yet implemented. */
-
- /* Return the `object address' for DW_OP_push_object_address. */
- CORE_ADDR (*get_object_address) (void *baton);
-#endif
+ /* Offset used to relocate DW_OP_addr, DW_OP_addrx, and
+ DW_OP_GNU_addr_index arguments. */
+ CORE_ADDR offset;
/* The current depth of dwarf expression recursion, via DW_OP_call*,
DW_OP_fbreg, DW_OP_push_object_address, etc., and the maximum
/* 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. */
+ target DIE of sect_offset kind. */
ULONGEST len;
const gdb_byte *data;
initialized; zero otherwise. */
int initialized;
- /* An array of pieces. PIECES points to its first element;
- NUM_PIECES is its length.
+ /* A vector of pieces.
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
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;
-};
+ std::vector<dwarf_expr_piece> pieces;
+ /* Return the value of register number REGNUM (a DWARF register number),
+ read as an address. */
+ virtual CORE_ADDR read_addr_from_reg (int regnum) = 0;
-/* A piece of an object, as recorded by DW_OP_piece or DW_OP_bit_piece. */
-struct dwarf_expr_piece
-{
- enum dwarf_value_location location;
+ /* Return a value of type TYPE, stored in register number REGNUM
+ of the frame associated to the given BATON.
- 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;
+ REGNUM is a DWARF register number. */
+ virtual struct value *get_reg_value (struct type *type, int regnum) = 0;
- /* The piece's register number, for DWARF_VALUE_REGISTER pieces. */
- int regno;
+ /* Read LENGTH bytes at ADDR into BUF. */
+ virtual void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t length) = 0;
- /* The piece's literal value, for DWARF_VALUE_STACK pieces. */
- struct value *value;
+ /* 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. */
+ virtual void get_frame_base (const gdb_byte **start, size_t *length) = 0;
- 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;
+ /* Return the CFA for the frame. */
+ virtual CORE_ADDR get_frame_cfa () = 0;
- /* Used for DWARF_VALUE_IMPLICIT_POINTER. */
- struct
- {
- /* The referent DIE from DW_OP_GNU_implicit_pointer. */
- ULONGEST die;
- /* The byte offset into the resulting data. */
- LONGEST offset;
- } ptr;
- } v;
+ /* Return the PC for the frame. */
+ virtual CORE_ADDR get_frame_pc ()
+ {
+ error (_("%s is invalid in this context"), "DW_OP_implicit_pointer");
+ }
- /* The length of the piece, in bits. */
- ULONGEST size;
- /* The piece offset, in bits. */
- ULONGEST offset;
+ /* Return the thread-local storage address for
+ DW_OP_GNU_push_tls_address or DW_OP_form_tls_address. */
+ virtual CORE_ADDR get_tls_address (CORE_ADDR offset) = 0;
+
+ /* Execute DW_AT_location expression for the DWARF expression
+ subroutine in the DIE at DIE_CU_OFF in the CU. Do not touch
+ STACK while it being passed to and returned from the called DWARF
+ subroutine. */
+ virtual void dwarf_call (cu_offset die_cu_off) = 0;
+
+ /* Execute "variable value" operation on the DIE at SECT_OFF. */
+ virtual struct value *dwarf_variable_value (sect_offset sect_off) = 0;
+
+ /* Return the base type given by the indicated DIE at DIE_CU_OFF.
+ This can throw an exception if the DIE is invalid or does not
+ represent a base type. SIZE is non-zero if this function should
+ verify that the resulting type has the correct size. */
+ virtual struct type *get_base_type (cu_offset die_cu_off, int size)
+ {
+ /* Anything will do. */
+ return builtin_type (this->gdbarch)->builtin_int;
+ }
+
+ /* Push on DWARF stack an entry evaluated for DW_TAG_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_call_data_value instead of
+ DW_AT_call_value. */
+ virtual void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind,
+ union call_site_parameter_u kind_u,
+ int deref_size) = 0;
+
+ /* Return the address indexed by DW_OP_addrx or DW_OP_GNU_addr_index.
+ This can throw an exception if the index is out of range. */
+ virtual CORE_ADDR get_addr_index (unsigned int index) = 0;
+
+ /* Return the `object address' for DW_OP_push_object_address. */
+ virtual CORE_ADDR get_object_address () = 0;
+
+private:
+
+ struct type *address_type () const;
+ void push (struct value *value, bool in_stack_memory);
+ bool stack_empty_p () const;
+ void add_piece (ULONGEST size, ULONGEST offset);
+ void execute_stack_op (const gdb_byte *op_ptr, const gdb_byte *op_end);
+ void pop ();
};
-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_require_composition (const gdb_byte *, const gdb_byte *,
+ const char *);
-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);
-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);
+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);
-const gdb_byte *read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end,
- ULONGEST * r);
-const gdb_byte *read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end,
- LONGEST * r);
+int dwarf_block_to_fb_offset (const gdb_byte *buf, const gdb_byte *buf_end,
+ CORE_ADDR *fb_offset_return);
-const char *dwarf_stack_op_name (unsigned int);
+int dwarf_block_to_sp_offset (struct gdbarch *gdbarch, const gdb_byte *buf,
+ const gdb_byte *buf_end,
+ CORE_ADDR *sp_offset_return);
-void dwarf_expr_require_composition (const gdb_byte *, const gdb_byte *,
- const char *);
+/* 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);
+
+extern const gdb_byte *safe_skip_leb128 (const gdb_byte *buf,
+ const gdb_byte *buf_end);
#endif /* dwarf2expr.h */
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