/* Find a variable's value in memory, for GDB, the GNU debugger.
- Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2007, 2008, 2009
- Free Software Foundation, Inc.
+ Copyright (C) 1986-2019 Free Software Foundation, Inc.
This file is part of GDB.
#include "gdbcore.h"
#include "inferior.h"
#include "target.h"
-#include "gdb_string.h"
-#include "gdb_assert.h"
-#include "floatformat.h"
#include "symfile.h" /* for overlay functions */
#include "regcache.h"
#include "user-regs.h"
#include "block.h"
#include "objfiles.h"
+#include "language.h"
+#include "dwarf2loc.h"
+#include "gdbsupport/selftest.h"
-/* Basic byte-swapping routines. GDB has needed these for a long time...
- All extract a target-format integer at ADDR which is LEN bytes long. */
+/* Basic byte-swapping routines. All 'extract' functions return a
+ host-format integer from a target-format integer at ADDR which is
+ LEN bytes long. */
#if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8
/* 8 bit characters are a pretty safe assumption these days, so we
you lose
#endif
-LONGEST
-extract_signed_integer (const gdb_byte *addr, int len)
+template<typename T, typename>
+T
+extract_integer (const gdb_byte *addr, int len, enum bfd_endian byte_order)
{
- LONGEST retval;
+ typename std::make_unsigned<T>::type retval = 0;
const unsigned char *p;
const unsigned char *startaddr = addr;
const unsigned char *endaddr = startaddr + len;
- if (len > (int) sizeof (LONGEST))
+ if (len > (int) sizeof (T))
error (_("\
That operation is not available on integers of more than %d bytes."),
- (int) sizeof (LONGEST));
+ (int) sizeof (T));
/* Start at the most significant end of the integer, and work towards
the least significant. */
- if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
+ if (byte_order == BFD_ENDIAN_BIG)
{
p = startaddr;
- /* Do the sign extension once at the start. */
- retval = ((LONGEST) * p ^ 0x80) - 0x80;
- for (++p; p < endaddr; ++p)
+ if (std::is_signed<T>::value)
+ {
+ /* Do the sign extension once at the start. */
+ retval = ((LONGEST) * p ^ 0x80) - 0x80;
+ ++p;
+ }
+ for (; p < endaddr; ++p)
retval = (retval << 8) | *p;
}
else
{
p = endaddr - 1;
- /* Do the sign extension once at the start. */
- retval = ((LONGEST) * p ^ 0x80) - 0x80;
- for (--p; p >= startaddr; --p)
+ if (std::is_signed<T>::value)
+ {
+ /* Do the sign extension once at the start. */
+ retval = ((LONGEST) * p ^ 0x80) - 0x80;
+ --p;
+ }
+ for (; p >= startaddr; --p)
retval = (retval << 8) | *p;
}
return retval;
}
-ULONGEST
-extract_unsigned_integer (const gdb_byte *addr, int len)
-{
- ULONGEST retval;
- const unsigned char *p;
- const unsigned char *startaddr = addr;
- const unsigned char *endaddr = startaddr + len;
-
- if (len > (int) sizeof (ULONGEST))
- error (_("\
-That operation is not available on integers of more than %d bytes."),
- (int) sizeof (ULONGEST));
-
- /* Start at the most significant end of the integer, and work towards
- the least significant. */
- retval = 0;
- if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
- {
- for (p = startaddr; p < endaddr; ++p)
- retval = (retval << 8) | *p;
- }
- else
- {
- for (p = endaddr - 1; p >= startaddr; --p)
- retval = (retval << 8) | *p;
- }
- return retval;
-}
+/* Explicit instantiations. */
+template LONGEST extract_integer<LONGEST> (const gdb_byte *addr, int len,
+ enum bfd_endian byte_order);
+template ULONGEST extract_integer<ULONGEST> (const gdb_byte *addr, int len,
+ enum bfd_endian byte_order);
/* Sometimes a long long unsigned integer can be extracted as a
LONGEST value. This is done so that we can print these values
int
extract_long_unsigned_integer (const gdb_byte *addr, int orig_len,
- LONGEST *pval)
+ enum bfd_endian byte_order, LONGEST *pval)
{
const gdb_byte *p;
const gdb_byte *first_addr;
int len;
len = orig_len;
- if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
+ if (byte_order == BFD_ENDIAN_BIG)
{
for (p = addr;
len > (int) sizeof (LONGEST) && p < addr + orig_len;
if (len <= (int) sizeof (LONGEST))
{
*pval = (LONGEST) extract_unsigned_integer (first_addr,
- sizeof (LONGEST));
+ sizeof (LONGEST),
+ byte_order);
return 1;
}
CORE_ADDR
extract_typed_address (const gdb_byte *buf, struct type *type)
{
- if (TYPE_CODE (type) != TYPE_CODE_PTR
- && TYPE_CODE (type) != TYPE_CODE_REF)
+ if (TYPE_CODE (type) != TYPE_CODE_PTR && !TYPE_IS_REFERENCE (type))
internal_error (__FILE__, __LINE__,
_("extract_typed_address: "
"type is not a pointer or reference"));
- return gdbarch_pointer_to_address (current_gdbarch, type, buf);
+ return gdbarch_pointer_to_address (get_type_arch (type), type, buf);
}
-
+/* All 'store' functions accept a host-format integer and store a
+ target-format integer at ADDR which is LEN bytes long. */
+template<typename T, typename>
void
-store_signed_integer (gdb_byte *addr, int len, LONGEST val)
+store_integer (gdb_byte *addr, int len, enum bfd_endian byte_order,
+ T val)
{
gdb_byte *p;
gdb_byte *startaddr = addr;
/* Start at the least significant end of the integer, and work towards
the most significant. */
- if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
+ if (byte_order == BFD_ENDIAN_BIG)
{
for (p = endaddr - 1; p >= startaddr; --p)
{
}
}
-void
-store_unsigned_integer (gdb_byte *addr, int len, ULONGEST val)
-{
- unsigned char *p;
- unsigned char *startaddr = (unsigned char *) addr;
- unsigned char *endaddr = startaddr + len;
+/* Explicit instantiations. */
+template void store_integer (gdb_byte *addr, int len,
+ enum bfd_endian byte_order,
+ LONGEST val);
- /* Start at the least significant end of the integer, and work towards
- the most significant. */
- if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
- {
- for (p = endaddr - 1; p >= startaddr; --p)
- {
- *p = val & 0xff;
- val >>= 8;
- }
- }
- else
- {
- for (p = startaddr; p < endaddr; ++p)
- {
- *p = val & 0xff;
- val >>= 8;
- }
- }
-}
+template void store_integer (gdb_byte *addr, int len,
+ enum bfd_endian byte_order,
+ ULONGEST val);
/* Store the address ADDR as a pointer of type TYPE at BUF, in target
form. */
void
store_typed_address (gdb_byte *buf, struct type *type, CORE_ADDR addr)
{
- if (TYPE_CODE (type) != TYPE_CODE_PTR
- && TYPE_CODE (type) != TYPE_CODE_REF)
+ if (TYPE_CODE (type) != TYPE_CODE_PTR && !TYPE_IS_REFERENCE (type))
internal_error (__FILE__, __LINE__,
_("store_typed_address: "
"type is not a pointer or reference"));
- gdbarch_address_to_pointer (current_gdbarch, type, buf, addr);
+ gdbarch_address_to_pointer (get_type_arch (type), type, buf, addr);
}
+/* Copy a value from SOURCE of size SOURCE_SIZE bytes to DEST of size DEST_SIZE
+ bytes. If SOURCE_SIZE is greater than DEST_SIZE, then truncate the most
+ significant bytes. If SOURCE_SIZE is less than DEST_SIZE then either sign
+ or zero extended according to IS_SIGNED. Values are stored in memory with
+ endianness BYTE_ORDER. */
+void
+copy_integer_to_size (gdb_byte *dest, int dest_size, const gdb_byte *source,
+ int source_size, bool is_signed,
+ enum bfd_endian byte_order)
+{
+ signed int size_diff = dest_size - source_size;
+
+ /* Copy across everything from SOURCE that can fit into DEST. */
+
+ if (byte_order == BFD_ENDIAN_BIG && size_diff > 0)
+ memcpy (dest + size_diff, source, source_size);
+ else if (byte_order == BFD_ENDIAN_BIG && size_diff < 0)
+ memcpy (dest, source - size_diff, dest_size);
+ else
+ memcpy (dest, source, std::min (source_size, dest_size));
+
+ /* Fill the remaining space in DEST by either zero extending or sign
+ extending. */
+
+ if (size_diff > 0)
+ {
+ gdb_byte extension = 0;
+ if (is_signed
+ && ((byte_order != BFD_ENDIAN_BIG && source[source_size - 1] & 0x80)
+ || (byte_order == BFD_ENDIAN_BIG && source[0] & 0x80)))
+ extension = 0xff;
+
+ /* Extend into MSBs of SOURCE. */
+ if (byte_order == BFD_ENDIAN_BIG)
+ memset (dest, extension, size_diff);
+ else
+ memset (dest + source_size, extension, size_diff);
+ }
+}
/* Return a `value' with the contents of (virtual or cooked) register
REGNUM as found in the specified FRAME. The register's type is
value_of_register (int regnum, struct frame_info *frame)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
- CORE_ADDR addr;
- int optim;
struct value *reg_val;
- int realnum;
- gdb_byte raw_buffer[MAX_REGISTER_SIZE];
- enum lval_type lval;
/* User registers lie completely outside of the range of normal
registers. Catch them early so that the target never sees them. */
- if (regnum >= gdbarch_num_regs (gdbarch)
- + gdbarch_num_pseudo_regs (gdbarch))
+ if (regnum >= gdbarch_num_cooked_regs (gdbarch))
return value_of_user_reg (regnum, frame);
- frame_register (frame, regnum, &optim, &lval, &addr, &realnum, raw_buffer);
-
- reg_val = allocate_value (register_type (gdbarch, regnum));
-
- memcpy (value_contents_raw (reg_val), raw_buffer,
- register_size (gdbarch, regnum));
- VALUE_LVAL (reg_val) = lval;
- set_value_address (reg_val, addr);
- VALUE_REGNUM (reg_val) = regnum;
- set_value_optimized_out (reg_val, optim);
- VALUE_FRAME_ID (reg_val) = get_frame_id (frame);
+ reg_val = value_of_register_lazy (frame, regnum);
+ value_fetch_lazy (reg_val);
return reg_val;
}
{
struct gdbarch *gdbarch = get_frame_arch (frame);
struct value *reg_val;
+ struct frame_info *next_frame;
- gdb_assert (regnum < (gdbarch_num_regs (gdbarch)
- + gdbarch_num_pseudo_regs (gdbarch)));
+ gdb_assert (regnum < gdbarch_num_cooked_regs (gdbarch));
- /* We should have a valid (i.e. non-sentinel) frame. */
- gdb_assert (frame_id_p (get_frame_id (frame)));
+ gdb_assert (frame != NULL);
- reg_val = allocate_value (register_type (gdbarch, regnum));
+ next_frame = get_next_frame_sentinel_okay (frame);
+
+ /* We should have a valid next frame. */
+ gdb_assert (frame_id_p (get_frame_id (next_frame)));
+
+ reg_val = allocate_value_lazy (register_type (gdbarch, regnum));
VALUE_LVAL (reg_val) = lval_register;
VALUE_REGNUM (reg_val) = regnum;
- VALUE_FRAME_ID (reg_val) = get_frame_id (frame);
- set_value_lazy (reg_val, 1);
+ VALUE_NEXT_FRAME_ID (reg_val) = get_frame_id (next_frame);
+
return reg_val;
}
unsigned_pointer_to_address (struct gdbarch *gdbarch,
struct type *type, const gdb_byte *buf)
{
- return extract_unsigned_integer (buf, TYPE_LENGTH (type));
+ enum bfd_endian byte_order = type_byte_order (type);
+
+ return extract_unsigned_integer (buf, TYPE_LENGTH (type), byte_order);
}
CORE_ADDR
signed_pointer_to_address (struct gdbarch *gdbarch,
struct type *type, const gdb_byte *buf)
{
- return extract_signed_integer (buf, TYPE_LENGTH (type));
+ enum bfd_endian byte_order = type_byte_order (type);
+
+ return extract_signed_integer (buf, TYPE_LENGTH (type), byte_order);
}
/* Given an address, store it as a pointer of type TYPE in target
unsigned_address_to_pointer (struct gdbarch *gdbarch, struct type *type,
gdb_byte *buf, CORE_ADDR addr)
{
- store_unsigned_integer (buf, TYPE_LENGTH (type), addr);
+ enum bfd_endian byte_order = type_byte_order (type);
+
+ store_unsigned_integer (buf, TYPE_LENGTH (type), byte_order, addr);
}
void
address_to_signed_pointer (struct gdbarch *gdbarch, struct type *type,
gdb_byte *buf, CORE_ADDR addr)
{
- store_signed_integer (buf, TYPE_LENGTH (type), addr);
+ enum bfd_endian byte_order = type_byte_order (type);
+
+ store_signed_integer (buf, TYPE_LENGTH (type), byte_order, addr);
}
\f
-/* Will calling read_var_value or locate_var_value on SYM end
- up caring what frame it is being evaluated relative to? SYM must
- be non-NULL. */
-int
-symbol_read_needs_frame (struct symbol *sym)
+/* See value.h. */
+
+enum symbol_needs_kind
+symbol_read_needs (struct symbol *sym)
{
+ if (SYMBOL_COMPUTED_OPS (sym) != NULL)
+ return SYMBOL_COMPUTED_OPS (sym)->get_symbol_read_needs (sym);
+
switch (SYMBOL_CLASS (sym))
{
/* All cases listed explicitly so that gcc -Wall will detect it if
we failed to consider one. */
case LOC_COMPUTED:
- /* FIXME: cagney/2004-01-26: It should be possible to
- unconditionally call the SYMBOL_COMPUTED_OPS method when available.
- Unfortunately DWARF 2 stores the frame-base (instead of the
- function) location in a function's symbol. Oops! For the
- moment enable this when/where applicable. */
- return SYMBOL_COMPUTED_OPS (sym)->read_needs_frame (sym);
+ gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
case LOC_REGISTER:
case LOC_ARG:
case LOC_REF_ARG:
case LOC_REGPARM_ADDR:
case LOC_LOCAL:
- return 1;
+ return SYMBOL_NEEDS_FRAME;
case LOC_UNDEF:
case LOC_CONST:
case LOC_CONST_BYTES:
case LOC_UNRESOLVED:
case LOC_OPTIMIZED_OUT:
- return 0;
+ return SYMBOL_NEEDS_NONE;
+ }
+ return SYMBOL_NEEDS_FRAME;
+}
+
+/* See value.h. */
+
+int
+symbol_read_needs_frame (struct symbol *sym)
+{
+ return symbol_read_needs (sym) == SYMBOL_NEEDS_FRAME;
+}
+
+/* Private data to be used with minsym_lookup_iterator_cb. */
+
+struct minsym_lookup_data
+{
+ /* The name of the minimal symbol we are searching for. */
+ const char *name;
+
+ /* The field where the callback should store the minimal symbol
+ if found. It should be initialized to NULL before the search
+ is started. */
+ struct bound_minimal_symbol result;
+};
+
+/* A callback function for gdbarch_iterate_over_objfiles_in_search_order.
+ It searches by name for a minimal symbol within the given OBJFILE.
+ The arguments are passed via CB_DATA, which in reality is a pointer
+ to struct minsym_lookup_data. */
+
+static int
+minsym_lookup_iterator_cb (struct objfile *objfile, void *cb_data)
+{
+ struct minsym_lookup_data *data = (struct minsym_lookup_data *) cb_data;
+
+ gdb_assert (data->result.minsym == NULL);
+
+ data->result = lookup_minimal_symbol (data->name, NULL, objfile);
+
+ /* The iterator should stop iff a match was found. */
+ return (data->result.minsym != NULL);
+}
+
+/* Given static link expression and the frame it lives in, look for the frame
+ the static links points to and return it. Return NULL if we could not find
+ such a frame. */
+
+static struct frame_info *
+follow_static_link (struct frame_info *frame,
+ const struct dynamic_prop *static_link)
+{
+ CORE_ADDR upper_frame_base;
+
+ if (!dwarf2_evaluate_property (static_link, frame, NULL, &upper_frame_base))
+ return NULL;
+
+ /* Now climb up the stack frame until we reach the frame we are interested
+ in. */
+ for (; frame != NULL; frame = get_prev_frame (frame))
+ {
+ struct symbol *framefunc = get_frame_function (frame);
+
+ /* Stacks can be quite deep: give the user a chance to stop this. */
+ QUIT;
+
+ /* If we don't know how to compute FRAME's base address, don't give up:
+ maybe the frame we are looking for is upper in the stack frame. */
+ if (framefunc != NULL
+ && SYMBOL_BLOCK_OPS (framefunc) != NULL
+ && SYMBOL_BLOCK_OPS (framefunc)->get_frame_base != NULL
+ && (SYMBOL_BLOCK_OPS (framefunc)->get_frame_base (framefunc, frame)
+ == upper_frame_base))
+ break;
}
- return 1;
+
+ return frame;
}
-/* Given a struct symbol for a variable,
- and a stack frame id, read the value of the variable
- and return a (pointer to a) struct value containing the value.
- If the variable cannot be found, return a zero pointer. */
+/* Assuming VAR is a symbol that can be reached from FRAME thanks to lexical
+ rules, look for the frame that is actually hosting VAR and return it. If,
+ for some reason, we found no such frame, return NULL.
+
+ This kind of computation is necessary to correctly handle lexically nested
+ functions.
+
+ Note that in some cases, we know what scope VAR comes from but we cannot
+ reach the specific frame that hosts the instance of VAR we are looking for.
+ For backward compatibility purposes (with old compilers), we then look for
+ the first frame that can host it. */
+
+static struct frame_info *
+get_hosting_frame (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
+{
+ const struct block *frame_block = NULL;
+
+ if (!symbol_read_needs_frame (var))
+ return NULL;
+
+ /* Some symbols for local variables have no block: this happens when they are
+ not produced by a debug information reader, for instance when GDB creates
+ synthetic symbols. Without block information, we must assume they are
+ local to FRAME. In this case, there is nothing to do. */
+ else if (var_block == NULL)
+ return frame;
+
+ /* We currently assume that all symbols with a location list need a frame.
+ This is true in practice because selecting the location description
+ requires to compute the CFA, hence requires a frame. However we have
+ tests that embed global/static symbols with null location lists.
+ We want to get <optimized out> instead of <frame required> when evaluating
+ them so return a frame instead of raising an error. */
+ else if (var_block == block_global_block (var_block)
+ || var_block == block_static_block (var_block))
+ return frame;
+
+ /* We have to handle the "my_func::my_local_var" notation. This requires us
+ to look for upper frames when we find no block for the current frame: here
+ and below, handle when frame_block == NULL. */
+ if (frame != NULL)
+ frame_block = get_frame_block (frame, NULL);
+
+ /* Climb up the call stack until reaching the frame we are looking for. */
+ while (frame != NULL && frame_block != var_block)
+ {
+ /* Stacks can be quite deep: give the user a chance to stop this. */
+ QUIT;
+
+ if (frame_block == NULL)
+ {
+ frame = get_prev_frame (frame);
+ if (frame == NULL)
+ break;
+ frame_block = get_frame_block (frame, NULL);
+ }
+
+ /* If we failed to find the proper frame, fallback to the heuristic
+ method below. */
+ else if (frame_block == block_global_block (frame_block))
+ {
+ frame = NULL;
+ break;
+ }
+
+ /* Assuming we have a block for this frame: if we are at the function
+ level, the immediate upper lexical block is in an outer function:
+ follow the static link. */
+ else if (BLOCK_FUNCTION (frame_block))
+ {
+ const struct dynamic_prop *static_link
+ = block_static_link (frame_block);
+ int could_climb_up = 0;
+
+ if (static_link != NULL)
+ {
+ frame = follow_static_link (frame, static_link);
+ if (frame != NULL)
+ {
+ frame_block = get_frame_block (frame, NULL);
+ could_climb_up = frame_block != NULL;
+ }
+ }
+ if (!could_climb_up)
+ {
+ frame = NULL;
+ break;
+ }
+ }
+
+ else
+ /* We must be in some function nested lexical block. Just get the
+ outer block: both must share the same frame. */
+ frame_block = BLOCK_SUPERBLOCK (frame_block);
+ }
+
+ /* Old compilers may not provide a static link, or they may provide an
+ invalid one. For such cases, fallback on the old way to evaluate
+ non-local references: just climb up the call stack and pick the first
+ frame that contains the variable we are looking for. */
+ if (frame == NULL)
+ {
+ frame = block_innermost_frame (var_block);
+ if (frame == NULL)
+ {
+ if (BLOCK_FUNCTION (var_block)
+ && !block_inlined_p (var_block)
+ && BLOCK_FUNCTION (var_block)->print_name ())
+ error (_("No frame is currently executing in block %s."),
+ BLOCK_FUNCTION (var_block)->print_name ());
+ else
+ error (_("No frame is currently executing in specified"
+ " block"));
+ }
+ }
+
+ return frame;
+}
+
+/* A default implementation for the "la_read_var_value" hook in
+ the language vector which should work in most situations. */
struct value *
-read_var_value (struct symbol *var, struct frame_info *frame)
+default_read_var_value (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
{
struct value *v;
struct type *type = SYMBOL_TYPE (var);
CORE_ADDR addr;
- int len;
+ enum symbol_needs_kind sym_need;
- if (SYMBOL_CLASS (var) == LOC_COMPUTED
- || SYMBOL_CLASS (var) == LOC_REGISTER)
- /* These cases do not use V. */
- v = NULL;
- else
- {
- v = allocate_value (type);
- VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */
- }
+ /* Call check_typedef on our type to make sure that, if TYPE is
+ a TYPE_CODE_TYPEDEF, its length is set to the length of the target type
+ instead of zero. However, we do not replace the typedef type by the
+ target type, because we want to keep the typedef in order to be able to
+ set the returned value type description correctly. */
+ check_typedef (type);
- len = TYPE_LENGTH (type);
+ sym_need = symbol_read_needs (var);
+ if (sym_need == SYMBOL_NEEDS_FRAME)
+ gdb_assert (frame != NULL);
+ else if (sym_need == SYMBOL_NEEDS_REGISTERS && !target_has_registers)
+ error (_("Cannot read `%s' without registers"), var->print_name ());
- if (symbol_read_needs_frame (var))
- gdb_assert (frame);
+ if (frame != NULL)
+ frame = get_hosting_frame (var, var_block, frame);
+
+ if (SYMBOL_COMPUTED_OPS (var) != NULL)
+ return SYMBOL_COMPUTED_OPS (var)->read_variable (var, frame);
switch (SYMBOL_CLASS (var))
{
case LOC_CONST:
- /* Put the constant back in target format. */
- store_signed_integer (value_contents_raw (v), len,
+ if (is_dynamic_type (type))
+ {
+ /* Value is a constant byte-sequence and needs no memory access. */
+ type = resolve_dynamic_type (type, NULL, /* Unused address. */ 0);
+ }
+ /* Put the constant back in target format. */
+ v = allocate_value (type);
+ store_signed_integer (value_contents_raw (v), TYPE_LENGTH (type),
+ type_byte_order (type),
(LONGEST) SYMBOL_VALUE (var));
VALUE_LVAL (v) = not_lval;
return v;
case LOC_LABEL:
/* Put the constant back in target format. */
+ v = allocate_value (type);
if (overlay_debugging)
{
- CORE_ADDR addr
+ addr
= symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
- SYMBOL_OBJ_SECTION (var));
+ SYMBOL_OBJ_SECTION (symbol_objfile (var),
+ var));
+
store_typed_address (value_contents_raw (v), type, addr);
}
else
return v;
case LOC_CONST_BYTES:
- {
- memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var), len);
- VALUE_LVAL (v) = not_lval;
- return v;
- }
+ if (is_dynamic_type (type))
+ {
+ /* Value is a constant byte-sequence and needs no memory access. */
+ type = resolve_dynamic_type (type, NULL, /* Unused address. */ 0);
+ }
+ v = allocate_value (type);
+ memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var),
+ TYPE_LENGTH (type));
+ VALUE_LVAL (v) = not_lval;
+ return v;
case LOC_STATIC:
if (overlay_debugging)
addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
- SYMBOL_OBJ_SECTION (var));
+ SYMBOL_OBJ_SECTION (symbol_objfile (var),
+ var));
else
addr = SYMBOL_VALUE_ADDRESS (var);
break;
case LOC_ARG:
addr = get_frame_args_address (frame);
if (!addr)
- return 0;
+ error (_("Unknown argument list address for `%s'."),
+ var->print_name ());
addr += SYMBOL_VALUE (var);
break;
{
struct value *ref;
CORE_ADDR argref;
+
argref = get_frame_args_address (frame);
if (!argref)
- return 0;
+ error (_("Unknown argument list address for `%s'."),
+ var->print_name ());
argref += SYMBOL_VALUE (var);
ref = value_at (lookup_pointer_type (type), argref);
addr = value_as_address (ref);
break;
case LOC_TYPEDEF:
- error (_("Cannot look up value of a typedef"));
+ error (_("Cannot look up value of a typedef `%s'."),
+ var->print_name ());
break;
case LOC_BLOCK:
if (overlay_debugging)
- set_value_address (v, symbol_overlayed_address
- (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_OBJ_SECTION (var)));
+ addr = symbol_overlayed_address
+ (BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (var)),
+ SYMBOL_OBJ_SECTION (symbol_objfile (var), var));
else
- set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (var)));
- return v;
+ addr = BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (var));
+ break;
case LOC_REGISTER:
case LOC_REGPARM_ADDR:
frame);
if (regval == NULL)
- error (_("Value of register variable not available."));
+ error (_("Value of register variable not available for `%s'."),
+ var->print_name ());
addr = value_as_address (regval);
- VALUE_LVAL (v) = lval_memory;
}
else
{
regval = value_from_register (type, regno, frame);
if (regval == NULL)
- error (_("Value of register variable not available."));
+ error (_("Value of register variable not available for `%s'."),
+ var->print_name ());
return regval;
}
}
break;
case LOC_COMPUTED:
- /* FIXME: cagney/2004-01-26: It should be possible to
- unconditionally call the SYMBOL_COMPUTED_OPS method when available.
- Unfortunately DWARF 2 stores the frame-base (instead of the
- function) location in a function's symbol. Oops! For the
- moment enable this when/where applicable. */
- return SYMBOL_COMPUTED_OPS (var)->read_variable (var, frame);
+ gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
case LOC_UNRESOLVED:
{
+ struct minsym_lookup_data lookup_data;
struct minimal_symbol *msym;
struct obj_section *obj_section;
- msym = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL);
+ memset (&lookup_data, 0, sizeof (lookup_data));
+ lookup_data.name = var->linkage_name ();
+
+ gdbarch_iterate_over_objfiles_in_search_order
+ (symbol_arch (var),
+ minsym_lookup_iterator_cb, &lookup_data,
+ symbol_objfile (var));
+ msym = lookup_data.result.minsym;
+
+ /* If we can't find the minsym there's a problem in the symbol info.
+ The symbol exists in the debug info, but it's missing in the minsym
+ table. */
if (msym == NULL)
- return 0;
- if (overlay_debugging)
- addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym),
- SYMBOL_OBJ_SECTION (msym));
+ {
+ const char *flavour_name
+ = objfile_flavour_name (symbol_objfile (var));
+
+ /* We can't get here unless we've opened the file, so flavour_name
+ can't be NULL. */
+ gdb_assert (flavour_name != NULL);
+ error (_("Missing %s symbol \"%s\"."),
+ flavour_name, var->linkage_name ());
+ }
+ obj_section = MSYMBOL_OBJ_SECTION (lookup_data.result.objfile, msym);
+ /* Relocate address, unless there is no section or the variable is
+ a TLS variable. */
+ if (obj_section == NULL
+ || (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0)
+ addr = MSYMBOL_VALUE_RAW_ADDRESS (msym);
else
- addr = SYMBOL_VALUE_ADDRESS (msym);
-
- obj_section = SYMBOL_OBJ_SECTION (msym);
+ addr = BMSYMBOL_VALUE_ADDRESS (lookup_data.result);
+ if (overlay_debugging)
+ addr = symbol_overlayed_address (addr, obj_section);
+ /* Determine address of TLS variable. */
if (obj_section
&& (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0)
addr = target_translate_tls_address (obj_section->objfile, addr);
break;
case LOC_OPTIMIZED_OUT:
- VALUE_LVAL (v) = not_lval;
- set_value_optimized_out (v, 1);
- return v;
+ if (is_dynamic_type (type))
+ type = resolve_dynamic_type (type, NULL, /* Unused address. */ 0);
+ return allocate_optimized_out_value (type);
default:
- error (_("Cannot look up value of a botched symbol."));
+ error (_("Cannot look up value of a botched symbol `%s'."),
+ var->print_name ());
break;
}
- set_value_address (v, addr);
- set_value_lazy (v, 1);
+ v = value_at_lazy (type, addr);
return v;
}
+/* Calls VAR's language la_read_var_value hook with the given arguments. */
+
+struct value *
+read_var_value (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
+{
+ const struct language_defn *lang = language_def (var->language ());
+
+ gdb_assert (lang != NULL);
+ gdb_assert (lang->la_read_var_value != NULL);
+
+ return lang->la_read_var_value (var, var_block, frame);
+}
+
/* Install default attributes for register values. */
struct value *
-default_value_from_register (struct type *type, int regnum,
- struct frame_info *frame)
+default_value_from_register (struct gdbarch *gdbarch, struct type *type,
+ int regnum, struct frame_id frame_id)
{
- struct gdbarch *gdbarch = get_frame_arch (frame);
int len = TYPE_LENGTH (type);
struct value *value = allocate_value (type);
+ struct frame_info *frame;
VALUE_LVAL (value) = lval_register;
- VALUE_FRAME_ID (value) = get_frame_id (frame);
+ frame = frame_find_by_id (frame_id);
+
+ if (frame == NULL)
+ frame_id = null_frame_id;
+ else
+ frame_id = get_frame_id (get_next_frame_sentinel_okay (frame));
+
+ VALUE_NEXT_FRAME_ID (value) = frame_id;
VALUE_REGNUM (value) = regnum;
/* Any structure stored in more than one register will always be
an integral number of registers. Otherwise, you need to do
some fiddling with the last register copied here for little
endian machines. */
- if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG
+ if (type_byte_order (type) == BFD_ENDIAN_BIG
&& len < register_size (gdbarch, regnum))
/* Big-endian, and we want less than full size. */
set_value_offset (value, register_size (gdbarch, regnum) - len);
return value;
}
+/* VALUE must be an lval_register value. If regnum is the value's
+ associated register number, and len the length of the values type,
+ read one or more registers in FRAME, starting with register REGNUM,
+ until we've read LEN bytes.
+
+ If any of the registers we try to read are optimized out, then mark the
+ complete resulting value as optimized out. */
+
+void
+read_frame_register_value (struct value *value, struct frame_info *frame)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ LONGEST offset = 0;
+ LONGEST reg_offset = value_offset (value);
+ int regnum = VALUE_REGNUM (value);
+ int len = type_length_units (check_typedef (value_type (value)));
+
+ gdb_assert (VALUE_LVAL (value) == lval_register);
+
+ /* Skip registers wholly inside of REG_OFFSET. */
+ while (reg_offset >= register_size (gdbarch, regnum))
+ {
+ reg_offset -= register_size (gdbarch, regnum);
+ regnum++;
+ }
+
+ /* Copy the data. */
+ while (len > 0)
+ {
+ struct value *regval = get_frame_register_value (frame, regnum);
+ int reg_len = type_length_units (value_type (regval)) - reg_offset;
+
+ /* If the register length is larger than the number of bytes
+ remaining to copy, then only copy the appropriate bytes. */
+ if (reg_len > len)
+ reg_len = len;
+
+ value_contents_copy (value, offset, regval, reg_offset, reg_len);
+
+ offset += reg_len;
+ len -= reg_len;
+ reg_offset = 0;
+ regnum++;
+ }
+}
+
/* Return a value of type TYPE, stored in register REGNUM, in frame FRAME. */
struct value *
if (gdbarch_convert_register_p (gdbarch, regnum, type1))
{
+ int optim, unavail, ok;
+
/* The ISA/ABI need to something weird when obtaining the
specified value from this register. It might need to
re-order non-adjacent, starting with REGNUM (see MIPS and
including the location. */
v = allocate_value (type);
VALUE_LVAL (v) = lval_register;
- VALUE_FRAME_ID (v) = get_frame_id (frame);
+ VALUE_NEXT_FRAME_ID (v) = get_frame_id (get_next_frame_sentinel_okay (frame));
VALUE_REGNUM (v) = regnum;
- gdbarch_register_to_value (gdbarch,
- frame, regnum, type1, value_contents_raw (v));
+ ok = gdbarch_register_to_value (gdbarch, frame, regnum, type1,
+ value_contents_raw (v), &optim,
+ &unavail);
+
+ if (!ok)
+ {
+ if (optim)
+ mark_value_bytes_optimized_out (v, 0, TYPE_LENGTH (type));
+ if (unavail)
+ mark_value_bytes_unavailable (v, 0, TYPE_LENGTH (type));
+ }
}
else
{
- int len = TYPE_LENGTH (type);
-
/* Construct the value. */
- v = gdbarch_value_from_register (gdbarch, type, regnum, frame);
+ v = gdbarch_value_from_register (gdbarch, type,
+ regnum, get_frame_id (frame));
/* Get the data. */
- if (!get_frame_register_bytes (frame, regnum, value_offset (v), len,
- value_contents_raw (v)))
- set_value_optimized_out (v, 1);
+ read_frame_register_value (v, frame);
}
+
return v;
}
-/* Return contents of register REGNUM in frame FRAME as address,
- interpreted as value of type TYPE. Will abort if register
- value is not available. */
+/* Return contents of register REGNUM in frame FRAME as address.
+ Will abort if register value is not available. */
CORE_ADDR
-address_from_register (struct type *type, int regnum, struct frame_info *frame)
+address_from_register (int regnum, struct frame_info *frame)
{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct type *type = builtin_type (gdbarch)->builtin_data_ptr;
struct value *value;
CORE_ADDR result;
+ int regnum_max_excl = gdbarch_num_cooked_regs (gdbarch);
+
+ if (regnum < 0 || regnum >= regnum_max_excl)
+ error (_("Invalid register #%d, expecting 0 <= # < %d"), regnum,
+ regnum_max_excl);
+
+ /* This routine may be called during early unwinding, at a time
+ where the ID of FRAME is not yet known. Calling value_from_register
+ would therefore abort in get_frame_id. However, since we only need
+ a temporary value that is never used as lvalue, we actually do not
+ really need to set its VALUE_NEXT_FRAME_ID. Therefore, we re-implement
+ the core of value_from_register, but use the null_frame_id. */
+
+ /* Some targets require a special conversion routine even for plain
+ pointer types. Avoid constructing a value object in those cases. */
+ if (gdbarch_convert_register_p (gdbarch, regnum, type))
+ {
+ gdb_byte *buf = (gdb_byte *) alloca (TYPE_LENGTH (type));
+ int optim, unavail, ok;
+
+ ok = gdbarch_register_to_value (gdbarch, frame, regnum, type,
+ buf, &optim, &unavail);
+ if (!ok)
+ {
+ /* This function is used while computing a location expression.
+ Complain about the value being optimized out, rather than
+ letting value_as_address complain about some random register
+ the expression depends on not being saved. */
+ error_value_optimized_out ();
+ }
+
+ return unpack_long (type, buf);
+ }
- value = value_from_register (type, regnum, frame);
- gdb_assert (value);
+ value = gdbarch_value_from_register (gdbarch, type, regnum, null_frame_id);
+ read_frame_register_value (value, frame);
+
+ if (value_optimized_out (value))
+ {
+ /* This function is used while computing a location expression.
+ Complain about the value being optimized out, rather than
+ letting value_as_address complain about some random register
+ the expression depends on not being saved. */
+ error_value_optimized_out ();
+ }
result = value_as_address (value);
release_value (value);
- value_free (value);
return result;
}
+
+#if GDB_SELF_TEST
+namespace selftests {
+namespace findvar_tests {
+
+/* Function to test copy_integer_to_size. Store SOURCE_VAL with size
+ SOURCE_SIZE to a buffer, making sure no sign extending happens at this
+ stage. Copy buffer to a new buffer using copy_integer_to_size. Extract
+ copied value and compare to DEST_VALU. Copy again with a signed
+ copy_integer_to_size and compare to DEST_VALS. Do everything for both
+ LITTLE and BIG target endians. Use unsigned values throughout to make
+ sure there are no implicit sign extensions. */
+
+static void
+do_cint_test (ULONGEST dest_valu, ULONGEST dest_vals, int dest_size,
+ ULONGEST src_val, int src_size)
+{
+ for (int i = 0; i < 2 ; i++)
+ {
+ gdb_byte srcbuf[sizeof (ULONGEST)] = {};
+ gdb_byte destbuf[sizeof (ULONGEST)] = {};
+ enum bfd_endian byte_order = i ? BFD_ENDIAN_BIG : BFD_ENDIAN_LITTLE;
+
+ /* Fill the src buffer (and later the dest buffer) with non-zero junk,
+ to ensure zero extensions aren't hidden. */
+ memset (srcbuf, 0xaa, sizeof (srcbuf));
+
+ /* Store (and later extract) using unsigned to ensure there are no sign
+ extensions. */
+ store_unsigned_integer (srcbuf, src_size, byte_order, src_val);
+
+ /* Test unsigned. */
+ memset (destbuf, 0xaa, sizeof (destbuf));
+ copy_integer_to_size (destbuf, dest_size, srcbuf, src_size, false,
+ byte_order);
+ SELF_CHECK (dest_valu == extract_unsigned_integer (destbuf, dest_size,
+ byte_order));
+
+ /* Test signed. */
+ memset (destbuf, 0xaa, sizeof (destbuf));
+ copy_integer_to_size (destbuf, dest_size, srcbuf, src_size, true,
+ byte_order);
+ SELF_CHECK (dest_vals == extract_unsigned_integer (destbuf, dest_size,
+ byte_order));
+ }
+}
+
+static void
+copy_integer_to_size_test ()
+{
+ /* Destination is bigger than the source, which has the signed bit unset. */
+ do_cint_test (0x12345678, 0x12345678, 8, 0x12345678, 4);
+ do_cint_test (0x345678, 0x345678, 8, 0x12345678, 3);
+
+ /* Destination is bigger than the source, which has the signed bit set. */
+ do_cint_test (0xdeadbeef, 0xffffffffdeadbeef, 8, 0xdeadbeef, 4);
+ do_cint_test (0xadbeef, 0xffffffffffadbeef, 8, 0xdeadbeef, 3);
+
+ /* Destination is smaller than the source. */
+ do_cint_test (0x5678, 0x5678, 2, 0x12345678, 3);
+ do_cint_test (0xbeef, 0xbeef, 2, 0xdeadbeef, 3);
+
+ /* Destination and source are the same size. */
+ do_cint_test (0x8765432112345678, 0x8765432112345678, 8, 0x8765432112345678,
+ 8);
+ do_cint_test (0x432112345678, 0x432112345678, 6, 0x8765432112345678, 6);
+ do_cint_test (0xfeedbeaddeadbeef, 0xfeedbeaddeadbeef, 8, 0xfeedbeaddeadbeef,
+ 8);
+ do_cint_test (0xbeaddeadbeef, 0xbeaddeadbeef, 6, 0xfeedbeaddeadbeef, 6);
+
+ /* Destination is bigger than the source. Source is bigger than 32bits. */
+ do_cint_test (0x3412345678, 0x3412345678, 8, 0x3412345678, 6);
+ do_cint_test (0xff12345678, 0xff12345678, 8, 0xff12345678, 6);
+ do_cint_test (0x432112345678, 0x432112345678, 8, 0x8765432112345678, 6);
+ do_cint_test (0xff2112345678, 0xffffff2112345678, 8, 0xffffff2112345678, 6);
+}
+
+} // namespace findvar_test
+} // namespace selftests
+
+#endif
+
+void
+_initialize_findvar (void)
+{
+#if GDB_SELF_TEST
+ selftests::register_test
+ ("copy_integer_to_size",
+ selftests::findvar_tests::copy_integer_to_size_test);
+#endif
+}
projects / deliverable / binutils-gdb.git / blobdiff