/* DWARF 2 Expression Evaluator.
- Copyright (C) 2001, 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
Contributed by Daniel Berlin <dan@dberlin.org>.
#if !defined (DWARF2EXPR_H)
#define DWARF2EXPR_H
+/* 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 dwarf expression stack. */
+
+struct dwarf_stack_value
+{
+ CORE_ADDR 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. */
- 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. */
int stack_len, stack_allocated;
+ /* Target architecture to use for address operations. */
+ struct gdbarch *gdbarch;
+
+ /* Target address size in bytes. */
+ int addr_size;
+
/* An opaque argument provided by the caller, which will be passed
to all of the callback functions. */
void *baton;
expression evaluation is complete. */
void (*get_frame_base) (void *baton, gdb_byte **start, size_t *length);
+ /* Return the CFA for the frame. */
+ CORE_ADDR (*get_frame_cfa) (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);
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 VALUE_LITERAL, a the current literal value's length and
+ data. */
+ ULONGEST len;
+ 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 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
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. */
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;
+ enum dwarf_value_location location;
+
+ union
+ {
+ struct
+ {
+ /* This piece's address or register number. */
+ CORE_ADDR value;
+ /* Non-zero if the piece is known to be in memory and on
+ the program's stack. */
+ int in_stack_memory;
+ } expr;
+
+ struct
+ {
+ /* A pointer to the data making up this piece, for literal
+ pieces. */
+ gdb_byte *data;
+ /* The length of the available data. */
+ ULONGEST length;
+ } literal;
+ } v;
/* The length of the piece, in bytes. */
ULONGEST size;
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_push (struct dwarf_expr_context *ctx, CORE_ADDR 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,
size_t len);
CORE_ADDR dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n);
+int dwarf_expr_fetch_in_stack_memory (struct dwarf_expr_context *ctx, int n);
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);
+CORE_ADDR dwarf2_read_address (struct gdbarch *gdbarch, gdb_byte *buf,
+ gdb_byte *buf_end, int addr_size);
#endif /* dwarf2expr.h */
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