/* 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) 1986-2017 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 "selftest.h"
/* Basic byte-swapping routines. All 'extract' functions return a
host-format integer from a target-format integer at ADDR which is
you lose
#endif
-LONGEST
-extract_signed_integer (const gdb_byte *addr, int len,
- enum bfd_endian byte_order)
+template<typename T, typename>
+T
+extract_integer (const gdb_byte *addr, int len, enum bfd_endian byte_order)
{
- LONGEST retval;
+ T 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 (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,
- enum bfd_endian byte_order)
-{
- 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 (byte_order == 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
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"));
/* 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,
- enum bfd_endian byte_order, LONGEST val)
+store_integer (gdb_byte *addr, int len, enum bfd_endian byte_order,
+ T val)
{
gdb_byte *p;
gdb_byte *startaddr = addr;
}
}
-void
-store_unsigned_integer (gdb_byte *addr, int len,
- enum bfd_endian byte_order, 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 (byte_order == 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 (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
+ endianess 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. */
+ gdbarch_num_pseudo_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)));
- /* We should have a valid (i.e. non-sentinel) frame. */
- gdb_assert (frame_id_p (get_frame_id (frame)));
+ gdb_assert (frame != NULL);
+
+ next_frame = get_next_frame_sentinel_okay (frame);
- reg_val = allocate_value (register_type (gdbarch, regnum));
+ /* 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;
}
struct type *type, const gdb_byte *buf)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
return extract_unsigned_integer (buf, TYPE_LENGTH (type), byte_order);
}
struct type *type, const gdb_byte *buf)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
return extract_signed_integer (buf, TYPE_LENGTH (type), byte_order);
}
gdb_byte *buf, CORE_ADDR addr)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
store_unsigned_integer (buf, TYPE_LENGTH (type), byte_order, addr);
}
gdb_byte *buf, CORE_ADDR addr)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
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 stace 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)
+ && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (var_block)))
+ error (_("No frame is currently executing in block %s."),
+ SYMBOL_PRINT_NAME (BLOCK_FUNCTION (var_block)));
+ 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);
+
+ 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"), SYMBOL_PRINT_NAME (var));
- len = TYPE_LENGTH (type);
+ if (frame != NULL)
+ frame = get_hosting_frame (var, var_block, frame);
- if (symbol_read_needs_frame (var))
- gdb_assert (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),
gdbarch_byte_order (get_type_arch (type)),
(LONGEST) SYMBOL_VALUE (var));
VALUE_LVAL (v) = not_lval;
case LOC_LABEL:
/* Put the constant back in target format. */
+ v = allocate_value (type);
if (overlay_debugging)
{
CORE_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'."),
+ SYMBOL_PRINT_NAME (var));
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'."),
+ SYMBOL_PRINT_NAME (var));
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'."),
+ SYMBOL_PRINT_NAME (var));
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_START (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_START (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'."),
+ SYMBOL_PRINT_NAME (var));
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'."),
+ SYMBOL_PRINT_NAME (var));
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 = SYMBOL_LINKAGE_NAME (var);
+
+ 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, SYMBOL_LINKAGE_NAME (var));
+ }
+ 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;
+ 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'."),
+ SYMBOL_PRINT_NAME (var));
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 (SYMBOL_LANGUAGE (var));
+
+ 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
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_regs (gdbarch)
+ + gdbarch_num_pseudo_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 = gdbarch_value_from_register (gdbarch, type, regnum, null_frame_id);
+ read_frame_register_value (value, frame);
- value = value_from_register (type, regnum, frame);
- gdb_assert (value);
+ 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);
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
+}