/* DWARF 2 location expression support for GDB.
- Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010, 2011
- Free Software Foundation, Inc.
+ Copyright (C) 2003, 2005, 2007-2012 Free Software Foundation, Inc.
Contributed by Daniel Jacobowitz, MontaVista Software, Inc.
#include "gdb_string.h"
#include "gdb_assert.h"
+DEF_VEC_I(int);
+
extern int dwarf2_always_disassemble;
static void dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
/* An end-of-list entry. */
if (low == 0 && high == 0)
- return NULL;
+ {
+ *locexpr_length = 0;
+ return NULL;
+ }
/* Otherwise, a location expression entry. */
low += base_address;
length = extract_unsigned_integer (loc_ptr, 2, byte_order);
loc_ptr += 2;
+ if (low == high && pc == low)
+ {
+ /* This is entry PC record present only at entry point
+ of a function. Verify it is really the function entry point. */
+
+ struct block *pc_block = block_for_pc (pc);
+ struct symbol *pc_func = NULL;
+
+ if (pc_block)
+ pc_func = block_linkage_function (pc_block);
+
+ if (pc_func && pc == BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func)))
+ {
+ *locexpr_length = length;
+ return loc_ptr;
+ }
+ }
+
if (pc >= low && pc < high)
{
*locexpr_length = length;
const gdb_byte **start, size_t *length)
{
if (SYMBOL_LOCATION_BATON (framefunc) == NULL)
- *start = NULL;
+ *length = 0;
else if (SYMBOL_COMPUTED_OPS (framefunc) == &dwarf2_loclist_funcs)
{
struct dwarf2_loclist_baton *symbaton;
*start = symbaton->data;
}
else
- *start = NULL;
+ *length = 0;
}
- if (*start == NULL)
+ if (*length == 0)
error (_("Could not find the frame base for \"%s\"."),
SYMBOL_NATURAL_NAME (framefunc));
}
call and return. */
static void
-per_cu_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset,
+per_cu_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset,
struct dwarf2_per_cu_data *per_cu,
CORE_ADDR (*get_frame_pc) (void *baton),
void *baton)
/* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc. */
static void
-dwarf_expr_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
+dwarf_expr_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset)
{
struct dwarf_expr_baton *debaton = ctx->baton;
/* Callback function for dwarf2_evaluate_loc_desc. */
static struct type *
-dwarf_expr_get_base_type (struct dwarf_expr_context *ctx, size_t die_offset)
+dwarf_expr_get_base_type (struct dwarf_expr_context *ctx,
+ cu_offset die_offset)
{
struct dwarf_expr_baton *debaton = ctx->baton;
return sym;
}
-/* Define VEC (CORE_ADDR) functions. */
-DEF_VEC_I (CORE_ADDR);
-
/* Verify function with entry point exact address ADDR can never call itself
via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it
can call itself via tail calls.
int iparams;
struct value *val;
struct dwarf2_locexpr_baton *dwarf_block;
- struct call_site_parameter *parameter;
+ /* Initialize it just to avoid a GCC false warning. */
+ struct call_site_parameter *parameter = NULL;
CORE_ADDR target_addr;
if (gdbarch != frame_unwind_arch (frame))
return parameter;
}
-/* Execute call_site_parameter's DWARF block for caller of the CTX's frame.
- CTX must be of dwarf_expr_ctx_funcs kind. See DWARF_REG and FB_OFFSET
- description at struct dwarf_expr_context_funcs->push_dwarf_reg_entry_value.
+/* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return
+ the normal DW_AT_GNU_call_site_value block. Otherwise return the
+ DW_AT_GNU_call_site_data_value (dereferenced) block.
+
+ TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned
+ struct value.
+
+ Function always returns non-NULL, non-optimized out value. It throws
+ NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */
+
+static struct value *
+dwarf_entry_parameter_to_value (struct call_site_parameter *parameter,
+ CORE_ADDR deref_size, struct type *type,
+ struct frame_info *caller_frame,
+ struct dwarf2_per_cu_data *per_cu)
+{
+ const gdb_byte *data_src;
+ gdb_byte *data;
+ size_t size;
+
+ data_src = deref_size == -1 ? parameter->value : parameter->data_value;
+ size = deref_size == -1 ? parameter->value_size : parameter->data_value_size;
+
+ /* DEREF_SIZE size is not verified here. */
+ if (data_src == NULL)
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("Cannot resolve DW_AT_GNU_call_site_data_value"));
+
+ /* DW_AT_GNU_call_site_value is a DWARF expression, not a DWARF
+ location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from
+ DWARF block. */
+ data = alloca (size + 1);
+ memcpy (data, data_src, size);
+ data[size] = DW_OP_stack_value;
+
+ return dwarf2_evaluate_loc_desc (type, caller_frame, data, size + 1, per_cu);
+}
+
+/* Execute call_site_parameter's DWARF block matching DEREF_SIZE for caller of
+ the CTX's frame. CTX must be of dwarf_expr_ctx_funcs kind. See DWARF_REG
+ and FB_OFFSET description at struct
+ dwarf_expr_context_funcs->push_dwarf_reg_entry_value.
The CTX caller can be from a different CU - per_cu_dwarf_call implementation
can be more simple as it does not support cross-CU DWARF executions. */
static void
dwarf_expr_push_dwarf_reg_entry_value (struct dwarf_expr_context *ctx,
- int dwarf_reg, CORE_ADDR fb_offset)
+ int dwarf_reg, CORE_ADDR fb_offset,
+ int deref_size)
{
struct dwarf_expr_baton *debaton;
struct frame_info *frame, *caller_frame;
parameter = dwarf_expr_reg_to_entry_parameter (frame, dwarf_reg, fb_offset,
&caller_per_cu);
- data_src = parameter->value;
- size = parameter->value_size;
+ data_src = deref_size == -1 ? parameter->value : parameter->data_value;
+ size = deref_size == -1 ? parameter->value_size : parameter->data_value_size;
+
+ /* DEREF_SIZE size is not verified here. */
+ if (data_src == NULL)
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("Cannot resolve DW_AT_GNU_call_site_data_value"));
baton_local.frame = caller_frame;
baton_local.per_cu = caller_per_cu;
ctx->baton = saved_ctx.baton;
}
+/* VALUE must be of type lval_computed with entry_data_value_funcs. Perform
+ the indirect method on it, that is use its stored target value, the sole
+ purpose of entry_data_value_funcs.. */
+
+static struct value *
+entry_data_value_coerce_ref (const struct value *value)
+{
+ struct type *checked_type = check_typedef (value_type (value));
+ struct value *target_val;
+
+ if (TYPE_CODE (checked_type) != TYPE_CODE_REF)
+ return NULL;
+
+ target_val = value_computed_closure (value);
+ value_incref (target_val);
+ return target_val;
+}
+
+/* Implement copy_closure. */
+
+static void *
+entry_data_value_copy_closure (const struct value *v)
+{
+ struct value *target_val = value_computed_closure (v);
+
+ value_incref (target_val);
+ return target_val;
+}
+
+/* Implement free_closure. */
+
+static void
+entry_data_value_free_closure (struct value *v)
+{
+ struct value *target_val = value_computed_closure (v);
+
+ value_free (target_val);
+}
+
+/* Vector for methods for an entry value reference where the referenced value
+ is stored in the caller. On the first dereference use
+ DW_AT_GNU_call_site_data_value in the caller. */
+
+static const struct lval_funcs entry_data_value_funcs =
+{
+ NULL, /* read */
+ NULL, /* write */
+ NULL, /* check_validity */
+ NULL, /* check_any_valid */
+ NULL, /* indirect */
+ entry_data_value_coerce_ref,
+ NULL, /* check_synthetic_pointer */
+ entry_data_value_copy_closure,
+ entry_data_value_free_closure
+};
+
+/* Read parameter of TYPE at (callee) FRAME's function entry. DWARF_REG and
+ FB_OFFSET are used to match DW_AT_location at the caller's
+ DW_TAG_GNU_call_site_parameter. See DWARF_REG and FB_OFFSET description at
+ struct dwarf_expr_context_funcs->push_dwarf_reg_entry_value.
+
+ Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
+ cannot resolve the parameter for any reason. */
+
+static struct value *
+value_of_dwarf_reg_entry (struct type *type, struct frame_info *frame,
+ int dwarf_reg, CORE_ADDR fb_offset)
+{
+ struct type *checked_type = check_typedef (type);
+ struct type *target_type = TYPE_TARGET_TYPE (checked_type);
+ struct frame_info *caller_frame = get_prev_frame (frame);
+ struct value *outer_val, *target_val, *val;
+ struct call_site_parameter *parameter;
+ struct dwarf2_per_cu_data *caller_per_cu;
+ CORE_ADDR addr;
+
+ parameter = dwarf_expr_reg_to_entry_parameter (frame, dwarf_reg, fb_offset,
+ &caller_per_cu);
+
+ outer_val = dwarf_entry_parameter_to_value (parameter, -1 /* deref_size */,
+ type, caller_frame,
+ caller_per_cu);
+
+ /* Check if DW_AT_GNU_call_site_data_value cannot be used. If it should be
+ used and it is not available do not fall back to OUTER_VAL - dereferencing
+ TYPE_CODE_REF with non-entry data value would give current value - not the
+ entry value. */
+
+ if (TYPE_CODE (checked_type) != TYPE_CODE_REF
+ || TYPE_TARGET_TYPE (checked_type) == NULL)
+ return outer_val;
+
+ target_val = dwarf_entry_parameter_to_value (parameter,
+ TYPE_LENGTH (target_type),
+ target_type, caller_frame,
+ caller_per_cu);
+
+ /* value_as_address dereferences TYPE_CODE_REF. */
+ addr = extract_typed_address (value_contents (outer_val), checked_type);
+
+ /* The target entry value has artificial address of the entry value
+ reference. */
+ VALUE_LVAL (target_val) = lval_memory;
+ set_value_address (target_val, addr);
+
+ release_value (target_val);
+ val = allocate_computed_value (type, &entry_data_value_funcs,
+ target_val /* closure */);
+
+ /* Copy the referencing pointer to the new computed value. */
+ memcpy (value_contents_raw (val), value_contents_raw (outer_val),
+ TYPE_LENGTH (checked_type));
+ set_value_lazy (val, 0);
+
+ return val;
+}
+
+/* Read parameter of TYPE at (callee) FRAME's function entry. DATA and
+ SIZE are DWARF block used to match DW_AT_location at the caller's
+ DW_TAG_GNU_call_site_parameter.
+
+ Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
+ cannot resolve the parameter for any reason. */
+
+static struct value *
+value_of_dwarf_block_entry (struct type *type, struct frame_info *frame,
+ const gdb_byte *block, size_t block_len)
+{
+ int dwarf_reg;
+ CORE_ADDR fb_offset;
+
+ dwarf_reg = dwarf_block_to_dwarf_reg (block, block + block_len);
+ if (dwarf_reg != -1)
+ return value_of_dwarf_reg_entry (type, frame, dwarf_reg, 0 /* unused */);
+
+ if (dwarf_block_to_fb_offset (block, block + block_len, &fb_offset))
+ return value_of_dwarf_reg_entry (type, frame, -1, fb_offset);
+
+ /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message
+ suppressed during normal operation. The expression can be arbitrary if
+ there is no caller-callee entry value binding expected. */
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("DWARF-2 expression error: DW_OP_GNU_entry_value is supported "
+ "only for single DW_OP_reg* or for DW_OP_fbreg(*)"));
+}
+
struct piece_closure
{
/* Reference count. */
check_pieced_value_validity,
check_pieced_value_invalid,
indirect_pieced_value,
+ NULL, /* coerce_ref */
check_pieced_synthetic_pointer,
copy_pieced_value_closure,
free_pieced_value_closure
/* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame. */
static void
-needs_frame_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
+needs_frame_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset)
{
struct needs_frame_baton *nf_baton = ctx->baton;
static void
needs_dwarf_reg_entry_value (struct dwarf_expr_context *ctx,
- int dwarf_reg, CORE_ADDR fb_offset)
+ int dwarf_reg, CORE_ADDR fb_offset, int deref_size)
{
struct needs_frame_baton *nf_baton = ctx->baton;
{
struct dwarf2_locexpr_baton block;
int size = (op == DW_OP_call2 ? 2 : 4);
+ cu_offset offset;
uoffset = extract_unsigned_integer (op_ptr, size, byte_order);
op_ptr += size;
- block = dwarf2_fetch_die_location_block (uoffset, per_cu,
+ offset.cu_off = uoffset;
+ block = dwarf2_fetch_die_location_block (offset, per_cu,
get_ax_pc, expr);
/* DW_OP_call_ref is currently not supported. */
return val;
}
+/* Return the value of SYMBOL in FRAME at (callee) FRAME's function
+ entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
+ will be thrown. */
+
+static struct value *
+locexpr_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame)
+{
+ struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+
+ return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, dlbaton->data,
+ dlbaton->size);
+}
+
/* Return non-zero iff we need a frame to evaluate SYMBOL. */
static int
locexpr_read_needs_frame (struct symbol *symbol)
static const gdb_byte *
disassemble_dwarf_expression (struct ui_file *stream,
struct gdbarch *arch, unsigned int addr_size,
- int offset_size,
+ int offset_size, const gdb_byte *start,
const gdb_byte *data, const gdb_byte *end,
- int all,
+ int indent, int all,
struct dwarf2_per_cu_data *per_cu)
{
- const gdb_byte *start = data;
-
- fprintf_filtered (stream, _("a complex DWARF expression:\n"));
-
while (data < end
&& (all
|| (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece)))
if (!name)
error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
op, (long) (data - 1 - start));
- fprintf_filtered (stream, " % 4ld: %s", (long) (data - 1 - start), name);
+ fprintf_filtered (stream, " %*ld: %s", indent + 4,
+ (long) (data - 1 - start), name);
switch (op)
{
case DW_OP_GNU_deref_type:
{
int addr_size = *data++;
- ULONGEST offset;
+ cu_offset offset;
struct type *type;
- data = read_uleb128 (data, end, &offset);
+ data = read_uleb128 (data, end, &ul);
+ offset.cu_off = ul;
type = dwarf2_get_die_type (offset, per_cu);
fprintf_filtered (stream, "<");
type_print (type, "", stream, -1);
- fprintf_filtered (stream, " [0x%s]> %d", phex_nz (offset, 0),
+ fprintf_filtered (stream, " [0x%s]> %d", phex_nz (offset.cu_off, 0),
addr_size);
}
break;
case DW_OP_GNU_const_type:
{
- ULONGEST type_die;
+ cu_offset type_die;
struct type *type;
- data = read_uleb128 (data, end, &type_die);
+ data = read_uleb128 (data, end, &ul);
+ type_die.cu_off = ul;
type = dwarf2_get_die_type (type_die, per_cu);
fprintf_filtered (stream, "<");
type_print (type, "", stream, -1);
- fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die, 0));
+ fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0));
}
break;
case DW_OP_GNU_regval_type:
{
- ULONGEST type_die, reg;
+ ULONGEST reg;
+ cu_offset type_die;
struct type *type;
data = read_uleb128 (data, end, ®);
- data = read_uleb128 (data, end, &type_die);
+ data = read_uleb128 (data, end, &ul);
+ type_die.cu_off = ul;
type = dwarf2_get_die_type (type_die, per_cu);
fprintf_filtered (stream, "<");
type_print (type, "", stream, -1);
- fprintf_filtered (stream, " [0x%s]> [$%s]", phex_nz (type_die, 0),
+ fprintf_filtered (stream, " [0x%s]> [$%s]",
+ phex_nz (type_die.cu_off, 0),
locexpr_regname (arch, reg));
}
break;
case DW_OP_GNU_convert:
case DW_OP_GNU_reinterpret:
{
- ULONGEST type_die;
+ cu_offset type_die;
- data = read_uleb128 (data, end, &type_die);
+ data = read_uleb128 (data, end, &ul);
+ type_die.cu_off = ul;
- if (type_die == 0)
+ if (type_die.cu_off == 0)
fprintf_filtered (stream, "<0>");
else
{
type = dwarf2_get_die_type (type_die, per_cu);
fprintf_filtered (stream, "<");
type_print (type, "", stream, -1);
- fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die, 0));
+ fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0));
}
}
break;
+
+ case DW_OP_GNU_entry_value:
+ data = read_uleb128 (data, end, &ul);
+ fputc_filtered ('\n', stream);
+ disassemble_dwarf_expression (stream, arch, addr_size, offset_size,
+ start, data, data + ul, indent + 2,
+ all, per_cu);
+ data += ul;
+ continue;
}
fprintf_filtered (stream, "\n");
disassemble = 0;
}
if (disassemble)
- data = disassemble_dwarf_expression (stream,
- get_objfile_arch (objfile),
- addr_size, offset_size, data, end,
- dwarf2_always_disassemble,
- per_cu);
+ {
+ fprintf_filtered (stream, _("a complex DWARF expression:\n"));
+ data = disassemble_dwarf_expression (stream,
+ get_objfile_arch (objfile),
+ addr_size, offset_size, data,
+ data, end, 0,
+ dwarf2_always_disassemble,
+ per_cu);
+ }
if (data < end)
{
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
- if (dlbaton->data == NULL || dlbaton->size == 0)
+ if (dlbaton->size == 0)
value->optimized_out = 1;
else
dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size,
evaluator. */
const struct symbol_computed_ops dwarf2_locexpr_funcs = {
locexpr_read_variable,
+ locexpr_read_variable_at_entry,
locexpr_read_needs_frame,
locexpr_describe_location,
locexpr_tracepoint_var_ref
CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0;
data = dwarf2_find_location_expression (dlbaton, &size, pc);
- if (data == NULL)
- val = allocate_optimized_out_value (SYMBOL_TYPE (symbol));
- else
- val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size,
- dlbaton->per_cu);
+ val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size,
+ dlbaton->per_cu);
return val;
}
+/* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function
+ entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
+ will be thrown.
+
+ Function always returns non-NULL value, it may be marked optimized out if
+ inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR
+ if it cannot resolve the parameter for any reason. */
+
+static struct value *
+loclist_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame)
+{
+ struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ const gdb_byte *data;
+ size_t size;
+ CORE_ADDR pc;
+
+ if (frame == NULL || !get_frame_func_if_available (frame, &pc))
+ return allocate_optimized_out_value (SYMBOL_TYPE (symbol));
+
+ data = dwarf2_find_location_expression (dlbaton, &size, pc);
+ if (data == NULL)
+ return allocate_optimized_out_value (SYMBOL_TYPE (symbol));
+
+ return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, data, size);
+}
+
/* Return non-zero iff we need a frame to evaluate SYMBOL. */
static int
loclist_read_needs_frame (struct symbol *symbol)
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
data = dwarf2_find_location_expression (dlbaton, &size, ax->scope);
- if (data == NULL || size == 0)
+ if (size == 0)
value->optimized_out = 1;
else
dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size,
evaluator and location lists. */
const struct symbol_computed_ops dwarf2_loclist_funcs = {
loclist_read_variable,
+ loclist_read_variable_at_entry,
loclist_read_needs_frame,
loclist_describe_location,
loclist_tracepoint_var_ref
};
+/* Provide a prototype to silence -Wmissing-prototypes. */
+extern initialize_file_ftype _initialize_dwarf2loc;
+
void
_initialize_dwarf2loc (void)
{
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