/* DWARF 2 Expression Evaluator.
- Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009
+ Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Contributed by Daniel Berlin <dan@dberlin.org>.
/* The location of a value. */
enum dwarf_value_location
{
- /* The piece is in memory. */
+ /* The piece is in memory.
+ The value on the dwarf stack is its address. */
DWARF_VALUE_MEMORY,
- /* The piece is in a register. */
+
+ /* The piece is in a register.
+ The value on the dwarf stack is the register number. */
DWARF_VALUE_REGISTER,
- /* The piece is on the stack. */
+
+ /* The piece is on the dwarf stack. */
DWARF_VALUE_STACK,
+
/* The piece is a literal. */
- DWARF_VALUE_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
+{
+ ULONGEST 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
struct dwarf_expr_context
{
/* The stack of values, allocated with xmalloc. */
- CORE_ADDR *stack;
+ struct dwarf_stack_value *stack;
/* The number of values currently pushed on the stack, and the
number of elements allocated to the stack. */
/* 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;
/* 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);
+ /* 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);
+
#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);
-
/* Return the `object address' for DW_OP_push_object_address. */
CORE_ADDR (*get_object_address) (void *baton);
#endif
/* Location of the value. */
enum dwarf_value_location location;
- /* For VALUE_LITERAL, a the current literal value's length and
- data. */
+ /* 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. */
ULONGEST len;
- gdb_byte *data;
+ const gdb_byte *data;
/* Initialization status of variable: Non-zero if variable has been
initialized; zero otherwise. */
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 location, and the size given as the operand to
- DW_OP_piece. We then pop the top value from the stack, rest the
+ 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
};
-/* 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
{
enum dwarf_value_location location;
union
{
- /* This piece's address or register number. */
- CORE_ADDR value;
+ 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 or literal value, for
+ DWARF_VALUE_REGISTER or DWARF_VALUE_STACK pieces. */
+ ULONGEST value;
struct
{
- /* A pointer to the data making up this piece, for literal
- pieces. */
- gdb_byte *data;
+ /* 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. */
+ ULONGEST die;
+ /* The byte offset into the resulting data. */
+ LONGEST offset;
+ } ptr;
} v;
- /* The length of the piece, in bytes. */
+ /* 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);
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_push (struct dwarf_expr_context *ctx, ULONGEST value,
+ int in_stack_memory);
void dwarf_expr_pop (struct dwarf_expr_context *ctx);
-void dwarf_expr_eval (struct dwarf_expr_context *ctx, unsigned char *addr,
+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);
+ULONGEST 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);
+
+
+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);
+const char *dwarf_stack_op_name (unsigned int);
-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 (struct gdbarch *gdbarch, gdb_byte *buf,
- gdb_byte *buf_end, int addr_size);
+void dwarf_expr_require_composition (const gdb_byte *, const gdb_byte *,
+ const char *);
#endif /* dwarf2expr.h */
projects / deliverable / binutils-gdb.git / blobdiff