/* DWARF 2 location expression support for GDB.
- Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010
- Free Software Foundation, Inc.
+ Copyright (C) 2003, 2005, 2007-2012 Free Software Foundation, Inc.
Contributed by Daniel Jacobowitz, MontaVista Software, Inc.
#include "objfiles.h"
#include "exceptions.h"
#include "block.h"
+#include "gdbcmd.h"
#include "dwarf2.h"
#include "dwarf2expr.h"
#include "gdb_string.h"
#include "gdb_assert.h"
-static void
-dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
- gdb_byte **start, size_t *length);
+extern int dwarf2_always_disassemble;
+
+static void dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
+ const gdb_byte **start, size_t *length);
+
+static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs;
-/* A helper function for dealing with location lists. Given a
+static struct value *dwarf2_evaluate_loc_desc_full (struct type *type,
+ struct frame_info *frame,
+ const gdb_byte *data,
+ unsigned short size,
+ struct dwarf2_per_cu_data *per_cu,
+ LONGEST byte_offset);
+
+/* A function for dealing with location lists. Given a
symbol baton (BATON) and a pc value (PC), find the appropriate
location expression, set *LOCEXPR_LENGTH, and return a pointer
to the beginning of the expression. Returns NULL on failure.
For now, only return the first matching location expression; there
can be more than one in the list. */
-static gdb_byte *
-find_location_expression (struct dwarf2_loclist_baton *baton,
- size_t *locexpr_length, CORE_ADDR pc)
+const gdb_byte *
+dwarf2_find_location_expression (struct dwarf2_loclist_baton *baton,
+ size_t *locexpr_length, CORE_ADDR pc)
{
CORE_ADDR low, high;
- gdb_byte *loc_ptr, *buf_end;
+ const gdb_byte *loc_ptr, *buf_end;
int length;
struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu);
struct gdbarch *gdbarch = get_objfile_arch (objfile);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu);
+ int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd);
CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
/* Adjust base_address for relocatable objects. */
- CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets,
- SECT_OFF_TEXT (objfile));
+ CORE_ADDR base_offset = dwarf2_per_cu_text_offset (baton->per_cu);
CORE_ADDR base_address = baton->base_address + base_offset;
loc_ptr = baton->data;
while (1)
{
if (buf_end - loc_ptr < 2 * addr_size)
- error (_("find_location_expression: Corrupted DWARF expression."));
+ error (_("dwarf2_find_location_expression: "
+ "Corrupted DWARF expression."));
+
+ if (signed_addr_p)
+ low = extract_signed_integer (loc_ptr, addr_size, byte_order);
+ else
+ low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ loc_ptr += addr_size;
- low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ if (signed_addr_p)
+ high = extract_signed_integer (loc_ptr, addr_size, byte_order);
+ else
+ high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
loc_ptr += addr_size;
/* A base-address-selection entry. */
- if (low == base_mask)
+ if ((low & base_mask) == base_mask)
{
- base_address = dwarf2_read_address (gdbarch,
- loc_ptr, buf_end, addr_size);
- loc_ptr += addr_size;
+ base_address = high + base_offset;
continue;
}
- high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
- loc_ptr += addr_size;
-
/* 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;
struct dwarf_expr_baton
{
struct frame_info *frame;
- struct objfile *objfile;
+ struct dwarf2_per_cu_data *per_cu;
};
/* Helper functions for dwarf2_evaluate_loc_desc. */
describing the frame base. Return a pointer to it in START and
its length in LENGTH. */
static void
-dwarf_expr_frame_base (void *baton, gdb_byte **start, size_t * length)
+dwarf_expr_frame_base (void *baton, const gdb_byte **start, size_t * length)
{
/* FIXME: cagney/2003-03-26: This code should be using
get_frame_base_address(), and then implement a dwarf2 specific
static void
dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
- gdb_byte **start, size_t *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;
symbaton = SYMBOL_LOCATION_BATON (framefunc);
- *start = find_location_expression (symbaton, length, pc);
+ *start = dwarf2_find_location_expression (symbaton, length, pc);
}
else
{
struct dwarf2_locexpr_baton *symbaton;
+
symbaton = SYMBOL_LOCATION_BATON (framefunc);
if (symbaton != NULL)
{
*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));
}
dwarf_expr_frame_cfa (void *baton)
{
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
+
return dwarf2_frame_cfa (debaton->frame);
}
+/* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
+ the frame in BATON. */
+
+static CORE_ADDR
+dwarf_expr_frame_pc (void *baton)
+{
+ struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
+
+ return get_frame_address_in_block (debaton->frame);
+}
+
/* Using the objfile specified in BATON, find the address for the
current thread's thread-local storage with offset OFFSET. */
static CORE_ADDR
dwarf_expr_tls_address (void *baton, CORE_ADDR offset)
{
struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
+ struct objfile *objfile = dwarf2_per_cu_objfile (debaton->per_cu);
- return target_translate_tls_address (debaton->objfile, offset);
+ return target_translate_tls_address (objfile, offset);
}
-struct piece_closure
+/* Call DWARF subroutine from DW_AT_location of DIE at DIE_OFFSET in
+ current CU (as is PER_CU). State of the CTX is not affected by the
+ call and return. */
+
+static void
+per_cu_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset,
+ struct dwarf2_per_cu_data *per_cu,
+ CORE_ADDR (*get_frame_pc) (void *baton),
+ void *baton)
{
- /* The number of pieces used to describe this variable. */
- int n_pieces;
+ struct dwarf2_locexpr_baton block;
- /* The architecture, used only for DWARF_VALUE_STACK. */
- struct gdbarch *arch;
+ block = dwarf2_fetch_die_location_block (die_offset, per_cu,
+ get_frame_pc, baton);
- /* The pieces themselves. */
- struct dwarf_expr_piece *pieces;
-};
+ /* DW_OP_call_ref is currently not supported. */
+ gdb_assert (block.per_cu == per_cu);
-/* Allocate a closure for a value formed from separately-described
- PIECES. */
+ dwarf_expr_eval (ctx, block.data, block.size);
+}
-static struct piece_closure *
-allocate_piece_closure (int n_pieces, struct dwarf_expr_piece *pieces,
- struct gdbarch *arch)
+/* 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)
{
- struct piece_closure *c = XZALLOC (struct piece_closure);
+ struct dwarf_expr_baton *debaton = ctx->baton;
- c->n_pieces = n_pieces;
- c->arch = arch;
- c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece);
+ per_cu_dwarf_call (ctx, die_offset, debaton->per_cu,
+ ctx->funcs->get_frame_pc, ctx->baton);
+}
- memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece));
+/* Callback function for dwarf2_evaluate_loc_desc. */
- return c;
+static struct type *
+dwarf_expr_get_base_type (struct dwarf_expr_context *ctx, size_t die_offset)
+{
+ struct dwarf_expr_baton *debaton = ctx->baton;
+
+ return dwarf2_get_die_type (die_offset, debaton->per_cu);
}
+/* See dwarf2loc.h. */
+
+int entry_values_debug = 0;
+
+/* Helper to set entry_values_debug. */
+
static void
-read_pieced_value (struct value *v)
+show_entry_values_debug (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
{
- int i;
- long offset = 0;
- gdb_byte *contents;
- struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
- struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v));
+ fprintf_filtered (file,
+ _("Entry values and tail call frames debugging is %s.\n"),
+ value);
+}
- contents = value_contents_raw (v);
- for (i = 0; i < c->n_pieces; i++)
- {
- struct dwarf_expr_piece *p = &c->pieces[i];
- switch (p->location)
- {
- case DWARF_VALUE_REGISTER:
- {
- struct gdbarch *arch = get_frame_arch (frame);
- int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch,
- p->v.expr.value);
- int reg_offset = 0;
+/* Find DW_TAG_GNU_call_site's DW_AT_GNU_call_site_target address.
+ CALLER_FRAME (for registers) can be NULL if it is not known. This function
+ always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */
- if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
- && p->size < register_size (arch, gdb_regnum))
- /* Big-endian, and we want less than full size. */
- reg_offset = register_size (arch, gdb_regnum) - p->size;
+static CORE_ADDR
+call_site_to_target_addr (struct gdbarch *call_site_gdbarch,
+ struct call_site *call_site,
+ struct frame_info *caller_frame)
+{
+ switch (FIELD_LOC_KIND (call_site->target))
+ {
+ case FIELD_LOC_KIND_DWARF_BLOCK:
+ {
+ struct dwarf2_locexpr_baton *dwarf_block;
+ struct value *val;
+ struct type *caller_core_addr_type;
+ struct gdbarch *caller_arch;
- get_frame_register_bytes (frame, gdb_regnum, reg_offset, p->size,
- contents + offset);
+ dwarf_block = FIELD_DWARF_BLOCK (call_site->target);
+ if (dwarf_block == NULL)
+ {
+ struct minimal_symbol *msym;
+
+ msym = lookup_minimal_symbol_by_pc (call_site->pc - 1);
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("DW_AT_GNU_call_site_target is not specified "
+ "at %s in %s"),
+ paddress (call_site_gdbarch, call_site->pc),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym));
+
}
- break;
-
- case DWARF_VALUE_MEMORY:
- if (p->v.expr.in_stack_memory)
- read_stack (p->v.expr.value, contents + offset, p->size);
- else
- read_memory (p->v.expr.value, contents + offset, p->size);
- break;
-
- case DWARF_VALUE_STACK:
+ if (caller_frame == NULL)
{
- gdb_byte bytes[sizeof (ULONGEST)];
- size_t n;
- int addr_size = gdbarch_addr_bit (c->arch) / 8;
- store_unsigned_integer (bytes, addr_size,
- gdbarch_byte_order (c->arch),
- p->v.expr.value);
- n = p->size;
- if (n > addr_size)
- n = addr_size;
- memcpy (contents + offset, bytes, n);
+ struct minimal_symbol *msym;
+
+ msym = lookup_minimal_symbol_by_pc (call_site->pc - 1);
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("DW_AT_GNU_call_site_target DWARF block resolving "
+ "requires known frame which is currently not "
+ "available at %s in %s"),
+ paddress (call_site_gdbarch, call_site->pc),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym));
+
}
- break;
+ caller_arch = get_frame_arch (caller_frame);
+ caller_core_addr_type = builtin_type (caller_arch)->builtin_func_ptr;
+ val = dwarf2_evaluate_loc_desc (caller_core_addr_type, caller_frame,
+ dwarf_block->data, dwarf_block->size,
+ dwarf_block->per_cu);
+ /* DW_AT_GNU_call_site_target is a DWARF expression, not a DWARF
+ location. */
+ if (VALUE_LVAL (val) == lval_memory)
+ return value_address (val);
+ else
+ return value_as_address (val);
+ }
- case DWARF_VALUE_LITERAL:
+ case FIELD_LOC_KIND_PHYSNAME:
+ {
+ const char *physname;
+ struct minimal_symbol *msym;
+
+ physname = FIELD_STATIC_PHYSNAME (call_site->target);
+ msym = lookup_minimal_symbol_text (physname, NULL);
+ if (msym == NULL)
{
- size_t n = p->size;
- if (n > p->v.literal.length)
- n = p->v.literal.length;
- memcpy (contents + offset, p->v.literal.data, n);
+ msym = lookup_minimal_symbol_by_pc (call_site->pc - 1);
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("Cannot find function \"%s\" for a call site target "
+ "at %s in %s"),
+ physname, paddress (call_site_gdbarch, call_site->pc),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym));
+
}
- break;
+ return SYMBOL_VALUE_ADDRESS (msym);
+ }
- default:
- internal_error (__FILE__, __LINE__, _("invalid location type"));
- }
- offset += p->size;
+ case FIELD_LOC_KIND_PHYSADDR:
+ return FIELD_STATIC_PHYSADDR (call_site->target);
+
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid call site target kind"));
}
}
+/* Convert function entry point exact address ADDR to the function which is
+ compliant with TAIL_CALL_LIST_COMPLETE condition. Throw
+ NO_ENTRY_VALUE_ERROR otherwise. */
+
+static struct symbol *
+func_addr_to_tail_call_list (struct gdbarch *gdbarch, CORE_ADDR addr)
+{
+ struct symbol *sym = find_pc_function (addr);
+ struct type *type;
+
+ if (sym == NULL || BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) != addr)
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("DW_TAG_GNU_call_site resolving failed to find function "
+ "name for address %s"),
+ paddress (gdbarch, addr));
+
+ type = SYMBOL_TYPE (sym);
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_FUNC);
+ gdb_assert (TYPE_SPECIFIC_FIELD (type) == TYPE_SPECIFIC_FUNC);
+
+ return sym;
+}
+
+/* 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.
+
+ If a funtion can tail call itself its entry value based parameters are
+ unreliable. There is no verification whether the value of some/all
+ parameters is unchanged through the self tail call, we expect if there is
+ a self tail call all the parameters can be modified. */
+
static void
-write_pieced_value (struct value *to, struct value *from)
+func_verify_no_selftailcall (struct gdbarch *gdbarch, CORE_ADDR verify_addr)
{
- int i;
- long offset = 0;
- gdb_byte *contents;
- struct piece_closure *c = (struct piece_closure *) value_computed_closure (to);
- struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to));
+ struct obstack addr_obstack;
+ struct cleanup *old_chain;
+ CORE_ADDR addr;
- if (frame == NULL)
- {
- set_value_optimized_out (to, 1);
- return;
- }
+ /* Track here CORE_ADDRs which were already visited. */
+ htab_t addr_hash;
+
+ /* The verification is completely unordered. Track here function addresses
+ which still need to be iterated. */
+ VEC (CORE_ADDR) *todo = NULL;
+
+ obstack_init (&addr_obstack);
+ old_chain = make_cleanup_obstack_free (&addr_obstack);
+ addr_hash = htab_create_alloc_ex (64, core_addr_hash, core_addr_eq, NULL,
+ &addr_obstack, hashtab_obstack_allocate,
+ NULL);
+ make_cleanup_htab_delete (addr_hash);
- contents = value_contents_raw (from);
- for (i = 0; i < c->n_pieces; i++)
+ make_cleanup (VEC_cleanup (CORE_ADDR), &todo);
+
+ VEC_safe_push (CORE_ADDR, todo, verify_addr);
+ while (!VEC_empty (CORE_ADDR, todo))
{
- struct dwarf_expr_piece *p = &c->pieces[i];
- switch (p->location)
- {
- case DWARF_VALUE_REGISTER:
- {
- struct gdbarch *arch = get_frame_arch (frame);
- int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.expr.value);
- int reg_offset = 0;
+ struct symbol *func_sym;
+ struct call_site *call_site;
- if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
- && p->size < register_size (arch, gdb_regnum))
- /* Big-endian, and we want less than full size. */
- reg_offset = register_size (arch, gdb_regnum) - p->size;
+ addr = VEC_pop (CORE_ADDR, todo);
- put_frame_register_bytes (frame, gdb_regnum, reg_offset, p->size,
- contents + offset);
- }
- break;
- case DWARF_VALUE_MEMORY:
- write_memory (p->v.expr.value, contents + offset, p->size);
- break;
- default:
- set_value_optimized_out (to, 1);
- return;
+ func_sym = func_addr_to_tail_call_list (gdbarch, addr);
+
+ for (call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym));
+ call_site; call_site = call_site->tail_call_next)
+ {
+ CORE_ADDR target_addr;
+ void **slot;
+
+ /* CALLER_FRAME with registers is not available for tail-call jumped
+ frames. */
+ target_addr = call_site_to_target_addr (gdbarch, call_site, NULL);
+
+ if (target_addr == verify_addr)
+ {
+ struct minimal_symbol *msym;
+
+ msym = lookup_minimal_symbol_by_pc (verify_addr);
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("DW_OP_GNU_entry_value resolving has found "
+ "function \"%s\" at %s can call itself via tail "
+ "calls"),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym),
+ paddress (gdbarch, verify_addr));
+ }
+
+ slot = htab_find_slot (addr_hash, &target_addr, INSERT);
+ if (*slot == NULL)
+ {
+ *slot = obstack_copy (&addr_obstack, &target_addr,
+ sizeof (target_addr));
+ VEC_safe_push (CORE_ADDR, todo, target_addr);
+ }
}
- offset += p->size;
}
-}
-static void *
-copy_pieced_value_closure (struct value *v)
-{
- struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
-
- return allocate_piece_closure (c->n_pieces, c->pieces, c->arch);
+ do_cleanups (old_chain);
}
+/* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for
+ ENTRY_VALUES_DEBUG. */
+
static void
-free_pieced_value_closure (struct value *v)
+tailcall_dump (struct gdbarch *gdbarch, const struct call_site *call_site)
{
- struct piece_closure *c = (struct piece_closure *) value_computed_closure (v);
+ CORE_ADDR addr = call_site->pc;
+ struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (addr - 1);
+
+ fprintf_unfiltered (gdb_stdlog, " %s(%s)", paddress (gdbarch, addr),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym));
- xfree (c->pieces);
- xfree (c);
}
-/* Functions for accessing a variable described by DW_OP_piece. */
-static struct lval_funcs pieced_value_funcs = {
- read_pieced_value,
- write_pieced_value,
- copy_pieced_value_closure,
- free_pieced_value_closure
-};
+/* vec.h needs single word type name, typedef it. */
+typedef struct call_site *call_sitep;
-/* Evaluate a location description, starting at DATA and with length
- SIZE, to find the current location of variable VAR in the context
- of FRAME. */
-static struct value *
-dwarf2_evaluate_loc_desc (struct symbol *var, struct frame_info *frame,
- gdb_byte *data, unsigned short size,
- struct dwarf2_per_cu_data *per_cu)
+/* Define VEC (call_sitep) functions. */
+DEF_VEC_P (call_sitep);
+
+/* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP
+ only top callers and bottom callees which are present in both. GDBARCH is
+ used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are
+ no remaining possibilities to provide unambiguous non-trivial result.
+ RESULTP should point to NULL on the first (initialization) call. Caller is
+ responsible for xfree of any RESULTP data. */
+
+static void
+chain_candidate (struct gdbarch *gdbarch, struct call_site_chain **resultp,
+ VEC (call_sitep) *chain)
{
- struct value *retval;
- struct dwarf_expr_baton baton;
- struct dwarf_expr_context *ctx;
- struct cleanup *old_chain;
+ struct call_site_chain *result = *resultp;
+ long length = VEC_length (call_sitep, chain);
+ int callers, callees, idx;
- if (size == 0)
+ if (result == NULL)
{
- retval = allocate_value (SYMBOL_TYPE (var));
- VALUE_LVAL (retval) = not_lval;
- set_value_optimized_out (retval, 1);
- return retval;
- }
+ /* Create the initial chain containing all the passed PCs. */
- baton.frame = frame;
- baton.objfile = dwarf2_per_cu_objfile (per_cu);
+ result = xmalloc (sizeof (*result) + sizeof (*result->call_site)
+ * (length - 1));
+ result->length = length;
+ result->callers = result->callees = length;
+ memcpy (result->call_site, VEC_address (call_sitep, chain),
+ sizeof (*result->call_site) * length);
+ *resultp = result;
- ctx = new_dwarf_expr_context ();
- old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+ if (entry_values_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "tailcall: initial:");
+ for (idx = 0; idx < length; idx++)
+ tailcall_dump (gdbarch, result->call_site[idx]);
+ fputc_unfiltered ('\n', gdb_stdlog);
+ }
- ctx->gdbarch = get_objfile_arch (baton.objfile);
- ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
- ctx->baton = &baton;
- ctx->read_reg = dwarf_expr_read_reg;
- ctx->read_mem = dwarf_expr_read_mem;
- ctx->get_frame_base = dwarf_expr_frame_base;
- ctx->get_frame_cfa = dwarf_expr_frame_cfa;
- ctx->get_tls_address = dwarf_expr_tls_address;
+ return;
+ }
- dwarf_expr_eval (ctx, data, size);
- if (ctx->num_pieces > 0)
+ if (entry_values_debug)
{
- struct piece_closure *c;
- struct frame_id frame_id = get_frame_id (frame);
+ fprintf_unfiltered (gdb_stdlog, "tailcall: compare:");
+ for (idx = 0; idx < length; idx++)
+ tailcall_dump (gdbarch, VEC_index (call_sitep, chain, idx));
+ fputc_unfiltered ('\n', gdb_stdlog);
+ }
- c = allocate_piece_closure (ctx->num_pieces, ctx->pieces, ctx->gdbarch);
- retval = allocate_computed_value (SYMBOL_TYPE (var),
- &pieced_value_funcs,
- c);
- VALUE_FRAME_ID (retval) = frame_id;
+ /* Intersect callers. */
+
+ callers = min (result->callers, length);
+ for (idx = 0; idx < callers; idx++)
+ if (result->call_site[idx] != VEC_index (call_sitep, chain, idx))
+ {
+ result->callers = idx;
+ break;
+ }
+
+ /* Intersect callees. */
+
+ callees = min (result->callees, length);
+ for (idx = 0; idx < callees; idx++)
+ if (result->call_site[result->length - 1 - idx]
+ != VEC_index (call_sitep, chain, length - 1 - idx))
+ {
+ result->callees = idx;
+ break;
+ }
+
+ if (entry_values_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "tailcall: reduced:");
+ for (idx = 0; idx < result->callers; idx++)
+ tailcall_dump (gdbarch, result->call_site[idx]);
+ fputs_unfiltered (" |", gdb_stdlog);
+ for (idx = 0; idx < result->callees; idx++)
+ tailcall_dump (gdbarch, result->call_site[result->length
+ - result->callees + idx]);
+ fputc_unfiltered ('\n', gdb_stdlog);
}
- else
+
+ if (result->callers == 0 && result->callees == 0)
{
- switch (ctx->location)
- {
- case DWARF_VALUE_REGISTER:
- {
- struct gdbarch *arch = get_frame_arch (frame);
- CORE_ADDR dwarf_regnum = dwarf_expr_fetch (ctx, 0);
- int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum);
- retval = value_from_register (SYMBOL_TYPE (var), gdb_regnum, frame);
- }
- break;
+ /* There are no common callers or callees. It could be also a direct
+ call (which has length 0) with ambiguous possibility of an indirect
+ call - CALLERS == CALLEES == 0 is valid during the first allocation
+ but any subsequence processing of such entry means ambiguity. */
+ xfree (result);
+ *resultp = NULL;
+ return;
+ }
- case DWARF_VALUE_MEMORY:
- {
- CORE_ADDR address = dwarf_expr_fetch (ctx, 0);
- int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
+ /* See call_site_find_chain_1 why there is no way to reach the bottom callee
+ PC again. In such case there must be two different code paths to reach
+ it, therefore some of the former determined intermediate PCs must differ
+ and the unambiguous chain gets shortened. */
+ gdb_assert (result->callers + result->callees < result->length);
+}
- retval = allocate_value (SYMBOL_TYPE (var));
- VALUE_LVAL (retval) = lval_memory;
- set_value_lazy (retval, 1);
- if (in_stack_memory)
- set_value_stack (retval, 1);
- set_value_address (retval, address);
- }
- break;
+/* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
+ assumed frames between them use GDBARCH. Use depth first search so we can
+ keep single CHAIN of call_site's back to CALLER_PC. Function recursion
+ would have needless GDB stack overhead. Caller is responsible for xfree of
+ the returned result. Any unreliability results in thrown
+ NO_ENTRY_VALUE_ERROR. */
- case DWARF_VALUE_STACK:
- {
- gdb_byte bytes[sizeof (ULONGEST)];
- ULONGEST value = (ULONGEST) dwarf_expr_fetch (ctx, 0);
- bfd_byte *contents;
- size_t n = ctx->addr_size;
+static struct call_site_chain *
+call_site_find_chain_1 (struct gdbarch *gdbarch, CORE_ADDR caller_pc,
+ CORE_ADDR callee_pc)
+{
+ struct func_type *func_specific;
+ struct obstack addr_obstack;
+ struct cleanup *back_to_retval, *back_to_workdata;
+ struct call_site_chain *retval = NULL;
+ struct call_site *call_site;
+
+ /* Mark CALL_SITEs so we do not visit the same ones twice. */
+ htab_t addr_hash;
+
+ /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's
+ call_site nor any possible call_site at CALLEE_PC's function is there.
+ Any CALL_SITE in CHAIN will be iterated to its siblings - via
+ TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */
+ VEC (call_sitep) *chain = NULL;
+
+ /* We are not interested in the specific PC inside the callee function. */
+ callee_pc = get_pc_function_start (callee_pc);
+ if (callee_pc == 0)
+ throw_error (NO_ENTRY_VALUE_ERROR, _("Unable to find function for PC %s"),
+ paddress (gdbarch, callee_pc));
+
+ back_to_retval = make_cleanup (free_current_contents, &retval);
+
+ obstack_init (&addr_obstack);
+ back_to_workdata = make_cleanup_obstack_free (&addr_obstack);
+ addr_hash = htab_create_alloc_ex (64, core_addr_hash, core_addr_eq, NULL,
+ &addr_obstack, hashtab_obstack_allocate,
+ NULL);
+ make_cleanup_htab_delete (addr_hash);
+
+ make_cleanup (VEC_cleanup (call_sitep), &chain);
+
+ /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site
+ at the target's function. All the possible tail call sites in the
+ target's function will get iterated as already pushed into CHAIN via their
+ TAIL_CALL_NEXT. */
+ call_site = call_site_for_pc (gdbarch, caller_pc);
+
+ while (call_site)
+ {
+ CORE_ADDR target_func_addr;
+ struct call_site *target_call_site;
- store_unsigned_integer (bytes, ctx->addr_size,
- gdbarch_byte_order (ctx->gdbarch),
- value);
- retval = allocate_value (SYMBOL_TYPE (var));
- contents = value_contents_raw (retval);
- if (n > TYPE_LENGTH (SYMBOL_TYPE (var)))
- n = TYPE_LENGTH (SYMBOL_TYPE (var));
- memcpy (contents, bytes, n);
- }
- break;
+ /* CALLER_FRAME with registers is not available for tail-call jumped
+ frames. */
+ target_func_addr = call_site_to_target_addr (gdbarch, call_site, NULL);
- case DWARF_VALUE_LITERAL:
- {
- bfd_byte *contents;
- size_t n = ctx->len;
+ if (target_func_addr == callee_pc)
+ {
+ chain_candidate (gdbarch, &retval, chain);
+ if (retval == NULL)
+ break;
- retval = allocate_value (SYMBOL_TYPE (var));
- contents = value_contents_raw (retval);
- if (n > TYPE_LENGTH (SYMBOL_TYPE (var)))
- n = TYPE_LENGTH (SYMBOL_TYPE (var));
- memcpy (contents, ctx->data, n);
- }
- break;
+ /* There is no way to reach CALLEE_PC again as we would prevent
+ entering it twice as being already marked in ADDR_HASH. */
+ target_call_site = NULL;
+ }
+ else
+ {
+ struct symbol *target_func;
- default:
- internal_error (__FILE__, __LINE__, _("invalid location type"));
+ target_func = func_addr_to_tail_call_list (gdbarch, target_func_addr);
+ target_call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func));
}
- }
- set_value_initialized (retval, ctx->initialized);
+ do
+ {
+ /* Attempt to visit TARGET_CALL_SITE. */
+
+ if (target_call_site)
+ {
+ void **slot;
+
+ slot = htab_find_slot (addr_hash, &target_call_site->pc, INSERT);
+ if (*slot == NULL)
+ {
+ /* Successfully entered TARGET_CALL_SITE. */
+
+ *slot = &target_call_site->pc;
+ VEC_safe_push (call_sitep, chain, target_call_site);
+ break;
+ }
+ }
+
+ /* Backtrack (without revisiting the originating call_site). Try the
+ callers's sibling; if there isn't any try the callers's callers's
+ sibling etc. */
+
+ target_call_site = NULL;
+ while (!VEC_empty (call_sitep, chain))
+ {
+ call_site = VEC_pop (call_sitep, chain);
+
+ gdb_assert (htab_find_slot (addr_hash, &call_site->pc,
+ NO_INSERT) != NULL);
+ htab_remove_elt (addr_hash, &call_site->pc);
+
+ target_call_site = call_site->tail_call_next;
+ if (target_call_site)
+ break;
+ }
+ }
+ while (target_call_site);
- do_cleanups (old_chain);
+ if (VEC_empty (call_sitep, chain))
+ call_site = NULL;
+ else
+ call_site = VEC_last (call_sitep, chain);
+ }
+ if (retval == NULL)
+ {
+ struct minimal_symbol *msym_caller, *msym_callee;
+
+ msym_caller = lookup_minimal_symbol_by_pc (caller_pc);
+ msym_callee = lookup_minimal_symbol_by_pc (callee_pc);
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("There are no unambiguously determinable intermediate "
+ "callers or callees between caller function \"%s\" at %s "
+ "and callee function \"%s\" at %s"),
+ (msym_caller == NULL
+ ? "???" : SYMBOL_PRINT_NAME (msym_caller)),
+ paddress (gdbarch, caller_pc),
+ (msym_callee == NULL
+ ? "???" : SYMBOL_PRINT_NAME (msym_callee)),
+ paddress (gdbarch, callee_pc));
+ }
+
+ do_cleanups (back_to_workdata);
+ discard_cleanups (back_to_retval);
return retval;
}
-\f
-/* Helper functions and baton for dwarf2_loc_desc_needs_frame. */
-
-struct needs_frame_baton
-{
- int needs_frame;
-};
-/* Reads from registers do require a frame. */
-static CORE_ADDR
-needs_frame_read_reg (void *baton, int regnum)
-{
- struct needs_frame_baton *nf_baton = baton;
- nf_baton->needs_frame = 1;
- return 1;
-}
+/* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
+ assumed frames between them use GDBARCH. If valid call_site_chain cannot be
+ constructed return NULL. Caller is responsible for xfree of the returned
+ result. */
-/* Reads from memory do not require a frame. */
-static void
-needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
+struct call_site_chain *
+call_site_find_chain (struct gdbarch *gdbarch, CORE_ADDR caller_pc,
+ CORE_ADDR callee_pc)
{
- memset (buf, 0, len);
-}
+ volatile struct gdb_exception e;
+ struct call_site_chain *retval = NULL;
-/* Frame-relative accesses do require a frame. */
+ TRY_CATCH (e, RETURN_MASK_ERROR)
+ {
+ retval = call_site_find_chain_1 (gdbarch, caller_pc, callee_pc);
+ }
+ if (e.reason < 0)
+ {
+ if (e.error == NO_ENTRY_VALUE_ERROR)
+ {
+ if (entry_values_debug)
+ exception_print (gdb_stdout, e);
+
+ return NULL;
+ }
+ else
+ throw_exception (e);
+ }
+ return retval;
+}
+
+/* Fetch call_site_parameter from caller matching the parameters. FRAME is for
+ callee. See DWARF_REG and FB_OFFSET description at struct
+ dwarf_expr_context_funcs->push_dwarf_reg_entry_value.
+
+ Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR
+ otherwise. */
+
+static struct call_site_parameter *
+dwarf_expr_reg_to_entry_parameter (struct frame_info *frame, int dwarf_reg,
+ CORE_ADDR fb_offset,
+ struct dwarf2_per_cu_data **per_cu_return)
+{
+ CORE_ADDR func_addr = get_frame_func (frame);
+ CORE_ADDR caller_pc;
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct frame_info *caller_frame = get_prev_frame (frame);
+ struct call_site *call_site;
+ int iparams;
+ struct value *val;
+ struct dwarf2_locexpr_baton *dwarf_block;
+ /* 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))
+ {
+ struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (func_addr);
+ struct gdbarch *caller_gdbarch = frame_unwind_arch (frame);
+
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("DW_OP_GNU_entry_value resolving callee gdbarch %s "
+ "(of %s (%s)) does not match caller gdbarch %s"),
+ gdbarch_bfd_arch_info (gdbarch)->printable_name,
+ paddress (gdbarch, func_addr),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym),
+ gdbarch_bfd_arch_info (caller_gdbarch)->printable_name);
+ }
+
+ if (caller_frame == NULL)
+ {
+ struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (func_addr);
+
+ throw_error (NO_ENTRY_VALUE_ERROR, _("DW_OP_GNU_entry_value resolving "
+ "requires caller of %s (%s)"),
+ paddress (gdbarch, func_addr),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym));
+ }
+ caller_pc = get_frame_pc (caller_frame);
+ call_site = call_site_for_pc (gdbarch, caller_pc);
+
+ target_addr = call_site_to_target_addr (gdbarch, call_site, caller_frame);
+ if (target_addr != func_addr)
+ {
+ struct minimal_symbol *target_msym, *func_msym;
+
+ target_msym = lookup_minimal_symbol_by_pc (target_addr);
+ func_msym = lookup_minimal_symbol_by_pc (func_addr);
+ throw_error (NO_ENTRY_VALUE_ERROR,
+ _("DW_OP_GNU_entry_value resolving expects callee %s at %s "
+ "but the called frame is for %s at %s"),
+ (target_msym == NULL ? "???"
+ : SYMBOL_PRINT_NAME (target_msym)),
+ paddress (gdbarch, target_addr),
+ func_msym == NULL ? "???" : SYMBOL_PRINT_NAME (func_msym),
+ paddress (gdbarch, func_addr));
+ }
+
+ /* No entry value based parameters would be reliable if this function can
+ call itself via tail calls. */
+ func_verify_no_selftailcall (gdbarch, func_addr);
+
+ for (iparams = 0; iparams < call_site->parameter_count; iparams++)
+ {
+ parameter = &call_site->parameter[iparams];
+ if (parameter->dwarf_reg == -1 && dwarf_reg == -1)
+ {
+ if (parameter->fb_offset == fb_offset)
+ break;
+ }
+ else if (parameter->dwarf_reg == dwarf_reg)
+ break;
+ }
+ if (iparams == call_site->parameter_count)
+ {
+ struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (caller_pc);
+
+ /* DW_TAG_GNU_call_site_parameter will be missing just if GCC could not
+ determine its value. */
+ throw_error (NO_ENTRY_VALUE_ERROR, _("Cannot find matching parameter "
+ "at DW_TAG_GNU_call_site %s at %s"),
+ paddress (gdbarch, caller_pc),
+ msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym));
+ }
+
+ *per_cu_return = call_site->per_cu;
+ return parameter;
+}
+
+/* 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 deref_size)
+{
+ struct dwarf_expr_baton *debaton;
+ struct frame_info *frame, *caller_frame;
+ struct dwarf2_per_cu_data *caller_per_cu;
+ struct dwarf_expr_baton baton_local;
+ struct dwarf_expr_context saved_ctx;
+ struct call_site_parameter *parameter;
+ const gdb_byte *data_src;
+ size_t size;
+
+ gdb_assert (ctx->funcs == &dwarf_expr_ctx_funcs);
+ debaton = ctx->baton;
+ frame = debaton->frame;
+ caller_frame = get_prev_frame (frame);
+
+ parameter = dwarf_expr_reg_to_entry_parameter (frame, dwarf_reg, fb_offset,
+ &caller_per_cu);
+ 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;
+
+ saved_ctx.gdbarch = ctx->gdbarch;
+ saved_ctx.addr_size = ctx->addr_size;
+ saved_ctx.offset = ctx->offset;
+ saved_ctx.baton = ctx->baton;
+ ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (baton_local.per_cu));
+ ctx->addr_size = dwarf2_per_cu_addr_size (baton_local.per_cu);
+ ctx->offset = dwarf2_per_cu_text_offset (baton_local.per_cu);
+ ctx->baton = &baton_local;
+
+ dwarf_expr_eval (ctx, data_src, size);
+
+ ctx->gdbarch = saved_ctx.gdbarch;
+ ctx->addr_size = saved_ctx.addr_size;
+ ctx->offset = saved_ctx.offset;
+ 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. */
+ int refc;
+
+ /* The CU from which this closure's expression came. */
+ struct dwarf2_per_cu_data *per_cu;
+
+ /* The number of pieces used to describe this variable. */
+ int n_pieces;
+
+ /* The target address size, used only for DWARF_VALUE_STACK. */
+ int addr_size;
+
+ /* The pieces themselves. */
+ struct dwarf_expr_piece *pieces;
+};
+
+/* Allocate a closure for a value formed from separately-described
+ PIECES. */
+
+static struct piece_closure *
+allocate_piece_closure (struct dwarf2_per_cu_data *per_cu,
+ int n_pieces, struct dwarf_expr_piece *pieces,
+ int addr_size)
+{
+ struct piece_closure *c = XZALLOC (struct piece_closure);
+ int i;
+
+ c->refc = 1;
+ c->per_cu = per_cu;
+ c->n_pieces = n_pieces;
+ c->addr_size = addr_size;
+ c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece);
+
+ memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece));
+ for (i = 0; i < n_pieces; ++i)
+ if (c->pieces[i].location == DWARF_VALUE_STACK)
+ value_incref (c->pieces[i].v.value);
+
+ return c;
+}
+
+/* The lowest-level function to extract bits from a byte buffer.
+ SOURCE is the buffer. It is updated if we read to the end of a
+ byte.
+ SOURCE_OFFSET_BITS is the offset of the first bit to read. It is
+ updated to reflect the number of bits actually read.
+ NBITS is the number of bits we want to read. It is updated to
+ reflect the number of bits actually read. This function may read
+ fewer bits.
+ BITS_BIG_ENDIAN is taken directly from gdbarch.
+ This function returns the extracted bits. */
+
+static unsigned int
+extract_bits_primitive (const gdb_byte **source,
+ unsigned int *source_offset_bits,
+ int *nbits, int bits_big_endian)
+{
+ unsigned int avail, mask, datum;
+
+ gdb_assert (*source_offset_bits < 8);
+
+ avail = 8 - *source_offset_bits;
+ if (avail > *nbits)
+ avail = *nbits;
+
+ mask = (1 << avail) - 1;
+ datum = **source;
+ if (bits_big_endian)
+ datum >>= 8 - (*source_offset_bits + *nbits);
+ else
+ datum >>= *source_offset_bits;
+ datum &= mask;
+
+ *nbits -= avail;
+ *source_offset_bits += avail;
+ if (*source_offset_bits >= 8)
+ {
+ *source_offset_bits -= 8;
+ ++*source;
+ }
+
+ return datum;
+}
+
+/* Extract some bits from a source buffer and move forward in the
+ buffer.
+
+ SOURCE is the source buffer. It is updated as bytes are read.
+ SOURCE_OFFSET_BITS is the offset into SOURCE. It is updated as
+ bits are read.
+ NBITS is the number of bits to read.
+ BITS_BIG_ENDIAN is taken directly from gdbarch.
+
+ This function returns the bits that were read. */
+
+static unsigned int
+extract_bits (const gdb_byte **source, unsigned int *source_offset_bits,
+ int nbits, int bits_big_endian)
+{
+ unsigned int datum;
+
+ gdb_assert (nbits > 0 && nbits <= 8);
+
+ datum = extract_bits_primitive (source, source_offset_bits, &nbits,
+ bits_big_endian);
+ if (nbits > 0)
+ {
+ unsigned int more;
+
+ more = extract_bits_primitive (source, source_offset_bits, &nbits,
+ bits_big_endian);
+ if (bits_big_endian)
+ datum <<= nbits;
+ else
+ more <<= nbits;
+ datum |= more;
+ }
+
+ return datum;
+}
+
+/* Write some bits into a buffer and move forward in the buffer.
+
+ DATUM is the bits to write. The low-order bits of DATUM are used.
+ DEST is the destination buffer. It is updated as bytes are
+ written.
+ DEST_OFFSET_BITS is the bit offset in DEST at which writing is
+ done.
+ NBITS is the number of valid bits in DATUM.
+ BITS_BIG_ENDIAN is taken directly from gdbarch. */
+
+static void
+insert_bits (unsigned int datum,
+ gdb_byte *dest, unsigned int dest_offset_bits,
+ int nbits, int bits_big_endian)
+{
+ unsigned int mask;
+
+ gdb_assert (dest_offset_bits + nbits <= 8);
+
+ mask = (1 << nbits) - 1;
+ if (bits_big_endian)
+ {
+ datum <<= 8 - (dest_offset_bits + nbits);
+ mask <<= 8 - (dest_offset_bits + nbits);
+ }
+ else
+ {
+ datum <<= dest_offset_bits;
+ mask <<= dest_offset_bits;
+ }
+
+ gdb_assert ((datum & ~mask) == 0);
+
+ *dest = (*dest & ~mask) | datum;
+}
+
+/* Copy bits from a source to a destination.
+
+ DEST is where the bits should be written.
+ DEST_OFFSET_BITS is the bit offset into DEST.
+ SOURCE is the source of bits.
+ SOURCE_OFFSET_BITS is the bit offset into SOURCE.
+ BIT_COUNT is the number of bits to copy.
+ BITS_BIG_ENDIAN is taken directly from gdbarch. */
+
+static void
+copy_bitwise (gdb_byte *dest, unsigned int dest_offset_bits,
+ const gdb_byte *source, unsigned int source_offset_bits,
+ unsigned int bit_count,
+ int bits_big_endian)
+{
+ unsigned int dest_avail;
+ int datum;
+
+ /* Reduce everything to byte-size pieces. */
+ dest += dest_offset_bits / 8;
+ dest_offset_bits %= 8;
+ source += source_offset_bits / 8;
+ source_offset_bits %= 8;
+
+ dest_avail = 8 - dest_offset_bits % 8;
+
+ /* See if we can fill the first destination byte. */
+ if (dest_avail < bit_count)
+ {
+ datum = extract_bits (&source, &source_offset_bits, dest_avail,
+ bits_big_endian);
+ insert_bits (datum, dest, dest_offset_bits, dest_avail, bits_big_endian);
+ ++dest;
+ dest_offset_bits = 0;
+ bit_count -= dest_avail;
+ }
+
+ /* Now, either DEST_OFFSET_BITS is byte-aligned, or we have fewer
+ than 8 bits remaining. */
+ gdb_assert (dest_offset_bits % 8 == 0 || bit_count < 8);
+ for (; bit_count >= 8; bit_count -= 8)
+ {
+ datum = extract_bits (&source, &source_offset_bits, 8, bits_big_endian);
+ *dest++ = (gdb_byte) datum;
+ }
+
+ /* Finally, we may have a few leftover bits. */
+ gdb_assert (bit_count <= 8 - dest_offset_bits % 8);
+ if (bit_count > 0)
+ {
+ datum = extract_bits (&source, &source_offset_bits, bit_count,
+ bits_big_endian);
+ insert_bits (datum, dest, dest_offset_bits, bit_count, bits_big_endian);
+ }
+}
+
+static void
+read_pieced_value (struct value *v)
+{
+ int i;
+ long offset = 0;
+ ULONGEST bits_to_skip;
+ gdb_byte *contents;
+ struct piece_closure *c
+ = (struct piece_closure *) value_computed_closure (v);
+ struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v));
+ size_t type_len;
+ size_t buffer_size = 0;
+ char *buffer = NULL;
+ struct cleanup *cleanup;
+ int bits_big_endian
+ = gdbarch_bits_big_endian (get_type_arch (value_type (v)));
+
+ if (value_type (v) != value_enclosing_type (v))
+ internal_error (__FILE__, __LINE__,
+ _("Should not be able to create a lazy value with "
+ "an enclosing type"));
+
+ cleanup = make_cleanup (free_current_contents, &buffer);
+
+ contents = value_contents_raw (v);
+ bits_to_skip = 8 * value_offset (v);
+ if (value_bitsize (v))
+ {
+ bits_to_skip += value_bitpos (v);
+ type_len = value_bitsize (v);
+ }
+ else
+ type_len = 8 * TYPE_LENGTH (value_type (v));
+
+ for (i = 0; i < c->n_pieces && offset < type_len; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size, this_size_bits;
+ long dest_offset_bits, source_offset_bits, source_offset;
+ const gdb_byte *intermediate_buffer;
+
+ /* Compute size, source, and destination offsets for copying, in
+ bits. */
+ this_size_bits = p->size;
+ if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
+ {
+ bits_to_skip -= this_size_bits;
+ continue;
+ }
+ if (this_size_bits > type_len - offset)
+ this_size_bits = type_len - offset;
+ if (bits_to_skip > 0)
+ {
+ dest_offset_bits = 0;
+ source_offset_bits = bits_to_skip;
+ this_size_bits -= bits_to_skip;
+ bits_to_skip = 0;
+ }
+ else
+ {
+ dest_offset_bits = offset;
+ source_offset_bits = 0;
+ }
+
+ this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
+ source_offset = source_offset_bits / 8;
+ if (buffer_size < this_size)
+ {
+ buffer_size = this_size;
+ buffer = xrealloc (buffer, buffer_size);
+ }
+ intermediate_buffer = buffer;
+
+ /* Copy from the source to DEST_BUFFER. */
+ switch (p->location)
+ {
+ case DWARF_VALUE_REGISTER:
+ {
+ struct gdbarch *arch = get_frame_arch (frame);
+ int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno);
+ int reg_offset = source_offset;
+
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+ && this_size < register_size (arch, gdb_regnum))
+ {
+ /* Big-endian, and we want less than full size. */
+ reg_offset = register_size (arch, gdb_regnum) - this_size;
+ /* We want the lower-order THIS_SIZE_BITS of the bytes
+ we extract from the register. */
+ source_offset_bits += 8 * this_size - this_size_bits;
+ }
+
+ if (gdb_regnum != -1)
+ {
+ int optim, unavail;
+
+ if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
+ this_size, buffer,
+ &optim, &unavail))
+ {
+ /* Just so garbage doesn't ever shine through. */
+ memset (buffer, 0, this_size);
+
+ if (optim)
+ set_value_optimized_out (v, 1);
+ if (unavail)
+ mark_value_bytes_unavailable (v, offset, this_size);
+ }
+ }
+ else
+ {
+ error (_("Unable to access DWARF register number %s"),
+ paddress (arch, p->v.regno));
+ }
+ }
+ break;
+
+ case DWARF_VALUE_MEMORY:
+ read_value_memory (v, offset,
+ p->v.mem.in_stack_memory,
+ p->v.mem.addr + source_offset,
+ buffer, this_size);
+ break;
+
+ case DWARF_VALUE_STACK:
+ {
+ size_t n = this_size;
+
+ if (n > c->addr_size - source_offset)
+ n = (c->addr_size >= source_offset
+ ? c->addr_size - source_offset
+ : 0);
+ if (n == 0)
+ {
+ /* Nothing. */
+ }
+ else
+ {
+ const gdb_byte *val_bytes = value_contents_all (p->v.value);
+
+ intermediate_buffer = val_bytes + source_offset;
+ }
+ }
+ break;
+
+ case DWARF_VALUE_LITERAL:
+ {
+ size_t n = this_size;
+
+ if (n > p->v.literal.length - source_offset)
+ n = (p->v.literal.length >= source_offset
+ ? p->v.literal.length - source_offset
+ : 0);
+ if (n != 0)
+ intermediate_buffer = p->v.literal.data + source_offset;
+ }
+ break;
+
+ /* These bits show up as zeros -- but do not cause the value
+ to be considered optimized-out. */
+ case DWARF_VALUE_IMPLICIT_POINTER:
+ break;
+
+ case DWARF_VALUE_OPTIMIZED_OUT:
+ set_value_optimized_out (v, 1);
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid location type"));
+ }
+
+ if (p->location != DWARF_VALUE_OPTIMIZED_OUT
+ && p->location != DWARF_VALUE_IMPLICIT_POINTER)
+ copy_bitwise (contents, dest_offset_bits,
+ intermediate_buffer, source_offset_bits % 8,
+ this_size_bits, bits_big_endian);
+
+ offset += this_size_bits;
+ }
+
+ do_cleanups (cleanup);
+}
+
+static void
+write_pieced_value (struct value *to, struct value *from)
+{
+ int i;
+ long offset = 0;
+ ULONGEST bits_to_skip;
+ const gdb_byte *contents;
+ struct piece_closure *c
+ = (struct piece_closure *) value_computed_closure (to);
+ struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to));
+ size_t type_len;
+ size_t buffer_size = 0;
+ char *buffer = NULL;
+ struct cleanup *cleanup;
+ int bits_big_endian
+ = gdbarch_bits_big_endian (get_type_arch (value_type (to)));
+
+ if (frame == NULL)
+ {
+ set_value_optimized_out (to, 1);
+ return;
+ }
+
+ cleanup = make_cleanup (free_current_contents, &buffer);
+
+ contents = value_contents (from);
+ bits_to_skip = 8 * value_offset (to);
+ if (value_bitsize (to))
+ {
+ bits_to_skip += value_bitpos (to);
+ type_len = value_bitsize (to);
+ }
+ else
+ type_len = 8 * TYPE_LENGTH (value_type (to));
+
+ for (i = 0; i < c->n_pieces && offset < type_len; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size_bits, this_size;
+ long dest_offset_bits, source_offset_bits, dest_offset, source_offset;
+ int need_bitwise;
+ const gdb_byte *source_buffer;
+
+ this_size_bits = p->size;
+ if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
+ {
+ bits_to_skip -= this_size_bits;
+ continue;
+ }
+ if (this_size_bits > type_len - offset)
+ this_size_bits = type_len - offset;
+ if (bits_to_skip > 0)
+ {
+ dest_offset_bits = bits_to_skip;
+ source_offset_bits = 0;
+ this_size_bits -= bits_to_skip;
+ bits_to_skip = 0;
+ }
+ else
+ {
+ dest_offset_bits = 0;
+ source_offset_bits = offset;
+ }
+
+ this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
+ source_offset = source_offset_bits / 8;
+ dest_offset = dest_offset_bits / 8;
+ if (dest_offset_bits % 8 == 0 && source_offset_bits % 8 == 0)
+ {
+ source_buffer = contents + source_offset;
+ need_bitwise = 0;
+ }
+ else
+ {
+ if (buffer_size < this_size)
+ {
+ buffer_size = this_size;
+ buffer = xrealloc (buffer, buffer_size);
+ }
+ source_buffer = buffer;
+ need_bitwise = 1;
+ }
+
+ switch (p->location)
+ {
+ case DWARF_VALUE_REGISTER:
+ {
+ struct gdbarch *arch = get_frame_arch (frame);
+ int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno);
+ int reg_offset = dest_offset;
+
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+ && this_size <= register_size (arch, gdb_regnum))
+ /* Big-endian, and we want less than full size. */
+ reg_offset = register_size (arch, gdb_regnum) - this_size;
+
+ if (gdb_regnum != -1)
+ {
+ if (need_bitwise)
+ {
+ int optim, unavail;
+
+ if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
+ this_size, buffer,
+ &optim, &unavail))
+ {
+ if (optim)
+ error (_("Can't do read-modify-write to "
+ "update bitfield; containing word has been "
+ "optimized out"));
+ if (unavail)
+ throw_error (NOT_AVAILABLE_ERROR,
+ _("Can't do read-modify-write to update "
+ "bitfield; containing word "
+ "is unavailable"));
+ }
+ copy_bitwise (buffer, dest_offset_bits,
+ contents, source_offset_bits,
+ this_size_bits,
+ bits_big_endian);
+ }
+
+ put_frame_register_bytes (frame, gdb_regnum, reg_offset,
+ this_size, source_buffer);
+ }
+ else
+ {
+ error (_("Unable to write to DWARF register number %s"),
+ paddress (arch, p->v.regno));
+ }
+ }
+ break;
+ case DWARF_VALUE_MEMORY:
+ if (need_bitwise)
+ {
+ /* Only the first and last bytes can possibly have any
+ bits reused. */
+ read_memory (p->v.mem.addr + dest_offset, buffer, 1);
+ read_memory (p->v.mem.addr + dest_offset + this_size - 1,
+ buffer + this_size - 1, 1);
+ copy_bitwise (buffer, dest_offset_bits,
+ contents, source_offset_bits,
+ this_size_bits,
+ bits_big_endian);
+ }
+
+ write_memory (p->v.mem.addr + dest_offset,
+ source_buffer, this_size);
+ break;
+ default:
+ set_value_optimized_out (to, 1);
+ break;
+ }
+ offset += this_size_bits;
+ }
+
+ do_cleanups (cleanup);
+}
+
+/* A helper function that checks bit validity in a pieced value.
+ CHECK_FOR indicates the kind of validity checking.
+ DWARF_VALUE_MEMORY means to check whether any bit is valid.
+ DWARF_VALUE_OPTIMIZED_OUT means to check whether any bit is
+ optimized out.
+ DWARF_VALUE_IMPLICIT_POINTER means to check whether the bits are an
+ implicit pointer. */
+
+static int
+check_pieced_value_bits (const struct value *value, int bit_offset,
+ int bit_length,
+ enum dwarf_value_location check_for)
+{
+ struct piece_closure *c
+ = (struct piece_closure *) value_computed_closure (value);
+ int i;
+ int validity = (check_for == DWARF_VALUE_MEMORY
+ || check_for == DWARF_VALUE_IMPLICIT_POINTER);
+
+ bit_offset += 8 * value_offset (value);
+ if (value_bitsize (value))
+ bit_offset += value_bitpos (value);
+
+ for (i = 0; i < c->n_pieces && bit_length > 0; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size_bits = p->size;
+
+ if (bit_offset > 0)
+ {
+ if (bit_offset >= this_size_bits)
+ {
+ bit_offset -= this_size_bits;
+ continue;
+ }
+
+ bit_length -= this_size_bits - bit_offset;
+ bit_offset = 0;
+ }
+ else
+ bit_length -= this_size_bits;
+
+ if (check_for == DWARF_VALUE_IMPLICIT_POINTER)
+ {
+ if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
+ return 0;
+ }
+ else if (p->location == DWARF_VALUE_OPTIMIZED_OUT
+ || p->location == DWARF_VALUE_IMPLICIT_POINTER)
+ {
+ if (validity)
+ return 0;
+ }
+ else
+ {
+ if (!validity)
+ return 1;
+ }
+ }
+
+ return validity;
+}
+
+static int
+check_pieced_value_validity (const struct value *value, int bit_offset,
+ int bit_length)
+{
+ return check_pieced_value_bits (value, bit_offset, bit_length,
+ DWARF_VALUE_MEMORY);
+}
+
+static int
+check_pieced_value_invalid (const struct value *value)
+{
+ return check_pieced_value_bits (value, 0,
+ 8 * TYPE_LENGTH (value_type (value)),
+ DWARF_VALUE_OPTIMIZED_OUT);
+}
+
+/* An implementation of an lval_funcs method to see whether a value is
+ a synthetic pointer. */
+
+static int
+check_pieced_synthetic_pointer (const struct value *value, int bit_offset,
+ int bit_length)
+{
+ return check_pieced_value_bits (value, bit_offset, bit_length,
+ DWARF_VALUE_IMPLICIT_POINTER);
+}
+
+/* A wrapper function for get_frame_address_in_block. */
+
+static CORE_ADDR
+get_frame_address_in_block_wrapper (void *baton)
+{
+ return get_frame_address_in_block (baton);
+}
+
+/* An implementation of an lval_funcs method to indirect through a
+ pointer. This handles the synthetic pointer case when needed. */
+
+static struct value *
+indirect_pieced_value (struct value *value)
+{
+ struct piece_closure *c
+ = (struct piece_closure *) value_computed_closure (value);
+ struct type *type;
+ struct frame_info *frame;
+ struct dwarf2_locexpr_baton baton;
+ int i, bit_offset, bit_length;
+ struct dwarf_expr_piece *piece = NULL;
+ LONGEST byte_offset;
+
+ type = check_typedef (value_type (value));
+ if (TYPE_CODE (type) != TYPE_CODE_PTR)
+ return NULL;
+
+ bit_length = 8 * TYPE_LENGTH (type);
+ bit_offset = 8 * value_offset (value);
+ if (value_bitsize (value))
+ bit_offset += value_bitpos (value);
+
+ for (i = 0; i < c->n_pieces && bit_length > 0; i++)
+ {
+ struct dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size_bits = p->size;
+
+ if (bit_offset > 0)
+ {
+ if (bit_offset >= this_size_bits)
+ {
+ bit_offset -= this_size_bits;
+ continue;
+ }
+
+ bit_length -= this_size_bits - bit_offset;
+ bit_offset = 0;
+ }
+ else
+ bit_length -= this_size_bits;
+
+ if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
+ return NULL;
+
+ if (bit_length != 0)
+ error (_("Invalid use of DW_OP_GNU_implicit_pointer"));
+
+ piece = p;
+ break;
+ }
+
+ frame = get_selected_frame (_("No frame selected."));
+
+ /* This is an offset requested by GDB, such as value subcripts. */
+ byte_offset = value_as_address (value);
+
+ gdb_assert (piece);
+ baton = dwarf2_fetch_die_location_block (piece->v.ptr.die, c->per_cu,
+ get_frame_address_in_block_wrapper,
+ frame);
+
+ return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
+ baton.data, baton.size, baton.per_cu,
+ piece->v.ptr.offset + byte_offset);
+}
+
+static void *
+copy_pieced_value_closure (const struct value *v)
+{
+ struct piece_closure *c
+ = (struct piece_closure *) value_computed_closure (v);
+
+ ++c->refc;
+ return c;
+}
+
+static void
+free_pieced_value_closure (struct value *v)
+{
+ struct piece_closure *c
+ = (struct piece_closure *) value_computed_closure (v);
+
+ --c->refc;
+ if (c->refc == 0)
+ {
+ int i;
+
+ for (i = 0; i < c->n_pieces; ++i)
+ if (c->pieces[i].location == DWARF_VALUE_STACK)
+ value_free (c->pieces[i].v.value);
+
+ xfree (c->pieces);
+ xfree (c);
+ }
+}
+
+/* Functions for accessing a variable described by DW_OP_piece. */
+static const struct lval_funcs pieced_value_funcs = {
+ read_pieced_value,
+ write_pieced_value,
+ 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 function which throws an error if a synthetic pointer is
+ invalid. */
+
+static void
+invalid_synthetic_pointer (void)
+{
+ error (_("access outside bounds of object "
+ "referenced via synthetic pointer"));
+}
+
+/* Virtual method table for dwarf2_evaluate_loc_desc_full below. */
+
+static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs =
+{
+ dwarf_expr_read_reg,
+ dwarf_expr_read_mem,
+ dwarf_expr_frame_base,
+ dwarf_expr_frame_cfa,
+ dwarf_expr_frame_pc,
+ dwarf_expr_tls_address,
+ dwarf_expr_dwarf_call,
+ dwarf_expr_get_base_type,
+ dwarf_expr_push_dwarf_reg_entry_value
+};
+
+/* Evaluate a location description, starting at DATA and with length
+ SIZE, to find the current location of variable of TYPE in the
+ context of FRAME. BYTE_OFFSET is applied after the contents are
+ computed. */
+
+static struct value *
+dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
+ const gdb_byte *data, unsigned short size,
+ struct dwarf2_per_cu_data *per_cu,
+ LONGEST byte_offset)
+{
+ struct value *retval;
+ struct dwarf_expr_baton baton;
+ struct dwarf_expr_context *ctx;
+ struct cleanup *old_chain, *value_chain;
+ struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
+ volatile struct gdb_exception ex;
+
+ if (byte_offset < 0)
+ invalid_synthetic_pointer ();
+
+ if (size == 0)
+ return allocate_optimized_out_value (type);
+
+ baton.frame = frame;
+ baton.per_cu = per_cu;
+
+ ctx = new_dwarf_expr_context ();
+ old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+ value_chain = make_cleanup_value_free_to_mark (value_mark ());
+
+ ctx->gdbarch = get_objfile_arch (objfile);
+ ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
+ ctx->ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu);
+ ctx->offset = dwarf2_per_cu_text_offset (per_cu);
+ ctx->baton = &baton;
+ ctx->funcs = &dwarf_expr_ctx_funcs;
+
+ TRY_CATCH (ex, RETURN_MASK_ERROR)
+ {
+ dwarf_expr_eval (ctx, data, size);
+ }
+ if (ex.reason < 0)
+ {
+ if (ex.error == NOT_AVAILABLE_ERROR)
+ {
+ do_cleanups (old_chain);
+ retval = allocate_value (type);
+ mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (type));
+ return retval;
+ }
+ else if (ex.error == NO_ENTRY_VALUE_ERROR)
+ {
+ if (entry_values_debug)
+ exception_print (gdb_stdout, ex);
+ do_cleanups (old_chain);
+ return allocate_optimized_out_value (type);
+ }
+ else
+ throw_exception (ex);
+ }
+
+ if (ctx->num_pieces > 0)
+ {
+ struct piece_closure *c;
+ struct frame_id frame_id = get_frame_id (frame);
+ ULONGEST bit_size = 0;
+ int i;
+
+ for (i = 0; i < ctx->num_pieces; ++i)
+ bit_size += ctx->pieces[i].size;
+ if (8 * (byte_offset + TYPE_LENGTH (type)) > bit_size)
+ invalid_synthetic_pointer ();
+
+ c = allocate_piece_closure (per_cu, ctx->num_pieces, ctx->pieces,
+ ctx->addr_size);
+ /* We must clean up the value chain after creating the piece
+ closure but before allocating the result. */
+ do_cleanups (value_chain);
+ retval = allocate_computed_value (type, &pieced_value_funcs, c);
+ VALUE_FRAME_ID (retval) = frame_id;
+ set_value_offset (retval, byte_offset);
+ }
+ else
+ {
+ switch (ctx->location)
+ {
+ case DWARF_VALUE_REGISTER:
+ {
+ struct gdbarch *arch = get_frame_arch (frame);
+ ULONGEST dwarf_regnum = value_as_long (dwarf_expr_fetch (ctx, 0));
+ int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum);
+
+ if (byte_offset != 0)
+ error (_("cannot use offset on synthetic pointer to register"));
+ do_cleanups (value_chain);
+ if (gdb_regnum != -1)
+ retval = value_from_register (type, gdb_regnum, frame);
+ else
+ error (_("Unable to access DWARF register number %s"),
+ paddress (arch, dwarf_regnum));
+ }
+ break;
+
+ case DWARF_VALUE_MEMORY:
+ {
+ CORE_ADDR address = dwarf_expr_fetch_address (ctx, 0);
+ int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
+
+ do_cleanups (value_chain);
+ retval = allocate_value_lazy (type);
+ VALUE_LVAL (retval) = lval_memory;
+ if (in_stack_memory)
+ set_value_stack (retval, 1);
+ set_value_address (retval, address + byte_offset);
+ }
+ break;
+
+ case DWARF_VALUE_STACK:
+ {
+ struct value *value = dwarf_expr_fetch (ctx, 0);
+ gdb_byte *contents;
+ const gdb_byte *val_bytes;
+ size_t n = TYPE_LENGTH (value_type (value));
+
+ if (byte_offset + TYPE_LENGTH (type) > n)
+ invalid_synthetic_pointer ();
+
+ val_bytes = value_contents_all (value);
+ val_bytes += byte_offset;
+ n -= byte_offset;
+
+ /* Preserve VALUE because we are going to free values back
+ to the mark, but we still need the value contents
+ below. */
+ value_incref (value);
+ do_cleanups (value_chain);
+ make_cleanup_value_free (value);
+
+ retval = allocate_value (type);
+ contents = value_contents_raw (retval);
+ if (n > TYPE_LENGTH (type))
+ {
+ struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile);
+
+ if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG)
+ val_bytes += n - TYPE_LENGTH (type);
+ n = TYPE_LENGTH (type);
+ }
+ memcpy (contents, val_bytes, n);
+ }
+ break;
+
+ case DWARF_VALUE_LITERAL:
+ {
+ bfd_byte *contents;
+ const bfd_byte *ldata;
+ size_t n = ctx->len;
+
+ if (byte_offset + TYPE_LENGTH (type) > n)
+ invalid_synthetic_pointer ();
+
+ do_cleanups (value_chain);
+ retval = allocate_value (type);
+ contents = value_contents_raw (retval);
+
+ ldata = ctx->data + byte_offset;
+ n -= byte_offset;
+
+ if (n > TYPE_LENGTH (type))
+ {
+ struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile);
+
+ if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG)
+ ldata += n - TYPE_LENGTH (type);
+ n = TYPE_LENGTH (type);
+ }
+ memcpy (contents, ldata, n);
+ }
+ break;
+
+ case DWARF_VALUE_OPTIMIZED_OUT:
+ do_cleanups (value_chain);
+ retval = allocate_optimized_out_value (type);
+ break;
+
+ /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
+ operation by execute_stack_op. */
+ case DWARF_VALUE_IMPLICIT_POINTER:
+ /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
+ it can only be encountered when making a piece. */
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid location type"));
+ }
+ }
+
+ set_value_initialized (retval, ctx->initialized);
+
+ do_cleanups (old_chain);
+
+ return retval;
+}
+
+/* The exported interface to dwarf2_evaluate_loc_desc_full; it always
+ passes 0 as the byte_offset. */
+
+struct value *
+dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
+ const gdb_byte *data, unsigned short size,
+ struct dwarf2_per_cu_data *per_cu)
+{
+ return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu, 0);
+}
+
+\f
+/* Helper functions and baton for dwarf2_loc_desc_needs_frame. */
+
+struct needs_frame_baton
+{
+ int needs_frame;
+ struct dwarf2_per_cu_data *per_cu;
+};
+
+/* Reads from registers do require a frame. */
+static CORE_ADDR
+needs_frame_read_reg (void *baton, int regnum)
+{
+ struct needs_frame_baton *nf_baton = baton;
+
+ nf_baton->needs_frame = 1;
+ return 1;
+}
+
+/* Reads from memory do not require a frame. */
+static void
+needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
+{
+ memset (buf, 0, len);
+}
+
+/* Frame-relative accesses do require a frame. */
static void
-needs_frame_frame_base (void *baton, gdb_byte **start, size_t * length)
+needs_frame_frame_base (void *baton, const gdb_byte **start, size_t * length)
{
static gdb_byte lit0 = DW_OP_lit0;
struct needs_frame_baton *nf_baton = baton;
needs_frame_frame_cfa (void *baton)
{
struct needs_frame_baton *nf_baton = baton;
+
nf_baton->needs_frame = 1;
return 1;
}
needs_frame_tls_address (void *baton, CORE_ADDR offset)
{
struct needs_frame_baton *nf_baton = baton;
+
nf_baton->needs_frame = 1;
return 1;
}
+/* 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)
+{
+ struct needs_frame_baton *nf_baton = ctx->baton;
+
+ per_cu_dwarf_call (ctx, die_offset, nf_baton->per_cu,
+ ctx->funcs->get_frame_pc, ctx->baton);
+}
+
+/* DW_OP_GNU_entry_value accesses require a caller, therefore a frame. */
+
+static void
+needs_dwarf_reg_entry_value (struct dwarf_expr_context *ctx,
+ int dwarf_reg, CORE_ADDR fb_offset, int deref_size)
+{
+ struct needs_frame_baton *nf_baton = ctx->baton;
+
+ nf_baton->needs_frame = 1;
+}
+
+/* Virtual method table for dwarf2_loc_desc_needs_frame below. */
+
+static const struct dwarf_expr_context_funcs needs_frame_ctx_funcs =
+{
+ needs_frame_read_reg,
+ needs_frame_read_mem,
+ needs_frame_frame_base,
+ needs_frame_frame_cfa,
+ needs_frame_frame_cfa, /* get_frame_pc */
+ needs_frame_tls_address,
+ needs_frame_dwarf_call,
+ NULL, /* get_base_type */
+ needs_dwarf_reg_entry_value
+};
+
/* Return non-zero iff the location expression at DATA (length SIZE)
requires a frame to evaluate. */
static int
-dwarf2_loc_desc_needs_frame (gdb_byte *data, unsigned short size,
+dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size,
struct dwarf2_per_cu_data *per_cu)
{
struct needs_frame_baton baton;
struct dwarf_expr_context *ctx;
int in_reg;
struct cleanup *old_chain;
+ struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
baton.needs_frame = 0;
+ baton.per_cu = per_cu;
ctx = new_dwarf_expr_context ();
old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+ make_cleanup_value_free_to_mark (value_mark ());
- ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (per_cu));
+ ctx->gdbarch = get_objfile_arch (objfile);
ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
+ ctx->ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu);
+ ctx->offset = dwarf2_per_cu_text_offset (per_cu);
ctx->baton = &baton;
- ctx->read_reg = needs_frame_read_reg;
- ctx->read_mem = needs_frame_read_mem;
- ctx->get_frame_base = needs_frame_frame_base;
- ctx->get_frame_cfa = needs_frame_frame_cfa;
- ctx->get_tls_address = needs_frame_tls_address;
+ ctx->funcs = &needs_frame_ctx_funcs;
dwarf_expr_eval (ctx, data, size);
{
int i;
- /* If the location has several pieces, and any of them are in
- registers, then we will need a frame to fetch them from. */
- for (i = 0; i < ctx->num_pieces; i++)
- if (ctx->pieces[i].location == DWARF_VALUE_REGISTER)
- in_reg = 1;
- }
+ /* If the location has several pieces, and any of them are in
+ registers, then we will need a frame to fetch them from. */
+ for (i = 0; i < ctx->num_pieces; i++)
+ if (ctx->pieces[i].location == DWARF_VALUE_REGISTER)
+ in_reg = 1;
+ }
+
+ do_cleanups (old_chain);
+
+ return baton.needs_frame || in_reg;
+}
+
+/* A helper function that throws an unimplemented error mentioning a
+ given DWARF operator. */
+
+static void
+unimplemented (unsigned int op)
+{
+ const char *name = dwarf_stack_op_name (op);
+
+ if (name)
+ error (_("DWARF operator %s cannot be translated to an agent expression"),
+ name);
+ else
+ error (_("Unknown DWARF operator 0x%02x cannot be translated "
+ "to an agent expression"),
+ op);
+}
+
+/* A helper function to convert a DWARF register to an arch register.
+ ARCH is the architecture.
+ DWARF_REG is the register.
+ This will throw an exception if the DWARF register cannot be
+ translated to an architecture register. */
+
+static int
+translate_register (struct gdbarch *arch, int dwarf_reg)
+{
+ int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg);
+ if (reg == -1)
+ error (_("Unable to access DWARF register number %d"), dwarf_reg);
+ return reg;
+}
+
+/* A helper function that emits an access to memory. ARCH is the
+ target architecture. EXPR is the expression which we are building.
+ NBITS is the number of bits we want to read. This emits the
+ opcodes needed to read the memory and then extract the desired
+ bits. */
+
+static void
+access_memory (struct gdbarch *arch, struct agent_expr *expr, ULONGEST nbits)
+{
+ ULONGEST nbytes = (nbits + 7) / 8;
+
+ gdb_assert (nbits > 0 && nbits <= sizeof (LONGEST));
+
+ if (trace_kludge)
+ ax_trace_quick (expr, nbytes);
+
+ if (nbits <= 8)
+ ax_simple (expr, aop_ref8);
+ else if (nbits <= 16)
+ ax_simple (expr, aop_ref16);
+ else if (nbits <= 32)
+ ax_simple (expr, aop_ref32);
+ else
+ ax_simple (expr, aop_ref64);
+
+ /* If we read exactly the number of bytes we wanted, we're done. */
+ if (8 * nbytes == nbits)
+ return;
+
+ if (gdbarch_bits_big_endian (arch))
+ {
+ /* On a bits-big-endian machine, we want the high-order
+ NBITS. */
+ ax_const_l (expr, 8 * nbytes - nbits);
+ ax_simple (expr, aop_rsh_unsigned);
+ }
+ else
+ {
+ /* On a bits-little-endian box, we want the low-order NBITS. */
+ ax_zero_ext (expr, nbits);
+ }
+}
+
+/* A helper function to return the frame's PC. */
+
+static CORE_ADDR
+get_ax_pc (void *baton)
+{
+ struct agent_expr *expr = baton;
+
+ return expr->scope;
+}
+
+/* Compile a DWARF location expression to an agent expression.
+
+ EXPR is the agent expression we are building.
+ LOC is the agent value we modify.
+ ARCH is the architecture.
+ ADDR_SIZE is the size of addresses, in bytes.
+ OP_PTR is the start of the location expression.
+ OP_END is one past the last byte of the location expression.
+
+ This will throw an exception for various kinds of errors -- for
+ example, if the expression cannot be compiled, or if the expression
+ is invalid. */
+
+void
+dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc,
+ struct gdbarch *arch, unsigned int addr_size,
+ const gdb_byte *op_ptr, const gdb_byte *op_end,
+ struct dwarf2_per_cu_data *per_cu)
+{
+ struct cleanup *cleanups;
+ int i, *offsets;
+ VEC(int) *dw_labels = NULL, *patches = NULL;
+ const gdb_byte * const base = op_ptr;
+ const gdb_byte *previous_piece = op_ptr;
+ enum bfd_endian byte_order = gdbarch_byte_order (arch);
+ ULONGEST bits_collected = 0;
+ unsigned int addr_size_bits = 8 * addr_size;
+ int bits_big_endian = gdbarch_bits_big_endian (arch);
+
+ offsets = xmalloc ((op_end - op_ptr) * sizeof (int));
+ cleanups = make_cleanup (xfree, offsets);
+
+ for (i = 0; i < op_end - op_ptr; ++i)
+ offsets[i] = -1;
+
+ make_cleanup (VEC_cleanup (int), &dw_labels);
+ make_cleanup (VEC_cleanup (int), &patches);
+
+ /* By default we are making an address. */
+ loc->kind = axs_lvalue_memory;
+
+ while (op_ptr < op_end)
+ {
+ enum dwarf_location_atom op = *op_ptr;
+ ULONGEST uoffset, reg;
+ LONGEST offset;
+ int i;
+
+ offsets[op_ptr - base] = expr->len;
+ ++op_ptr;
+
+ /* Our basic approach to code generation is to map DWARF
+ operations directly to AX operations. However, there are
+ some differences.
+
+ First, DWARF works on address-sized units, but AX always uses
+ LONGEST. For most operations we simply ignore this
+ difference; instead we generate sign extensions as needed
+ before division and comparison operations. It would be nice
+ to omit the sign extensions, but there is no way to determine
+ the size of the target's LONGEST. (This code uses the size
+ of the host LONGEST in some cases -- that is a bug but it is
+ difficult to fix.)
+
+ Second, some DWARF operations cannot be translated to AX.
+ For these we simply fail. See
+ http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
+ switch (op)
+ {
+ case DW_OP_lit0:
+ case DW_OP_lit1:
+ case DW_OP_lit2:
+ case DW_OP_lit3:
+ case DW_OP_lit4:
+ case DW_OP_lit5:
+ case DW_OP_lit6:
+ case DW_OP_lit7:
+ case DW_OP_lit8:
+ case DW_OP_lit9:
+ case DW_OP_lit10:
+ case DW_OP_lit11:
+ case DW_OP_lit12:
+ case DW_OP_lit13:
+ case DW_OP_lit14:
+ case DW_OP_lit15:
+ case DW_OP_lit16:
+ case DW_OP_lit17:
+ case DW_OP_lit18:
+ case DW_OP_lit19:
+ case DW_OP_lit20:
+ case DW_OP_lit21:
+ case DW_OP_lit22:
+ case DW_OP_lit23:
+ case DW_OP_lit24:
+ case DW_OP_lit25:
+ case DW_OP_lit26:
+ case DW_OP_lit27:
+ case DW_OP_lit28:
+ case DW_OP_lit29:
+ case DW_OP_lit30:
+ case DW_OP_lit31:
+ ax_const_l (expr, op - DW_OP_lit0);
+ break;
+
+ case DW_OP_addr:
+ uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order);
+ op_ptr += addr_size;
+ /* Some versions of GCC emit DW_OP_addr before
+ DW_OP_GNU_push_tls_address. In this case the value is an
+ index, not an address. We don't support things like
+ branching between the address and the TLS op. */
+ if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address)
+ uoffset += dwarf2_per_cu_text_offset (per_cu);
+ ax_const_l (expr, uoffset);
+ break;
+
+ case DW_OP_const1u:
+ ax_const_l (expr, extract_unsigned_integer (op_ptr, 1, byte_order));
+ op_ptr += 1;
+ break;
+ case DW_OP_const1s:
+ ax_const_l (expr, extract_signed_integer (op_ptr, 1, byte_order));
+ op_ptr += 1;
+ break;
+ case DW_OP_const2u:
+ ax_const_l (expr, extract_unsigned_integer (op_ptr, 2, byte_order));
+ op_ptr += 2;
+ break;
+ case DW_OP_const2s:
+ ax_const_l (expr, extract_signed_integer (op_ptr, 2, byte_order));
+ op_ptr += 2;
+ break;
+ case DW_OP_const4u:
+ ax_const_l (expr, extract_unsigned_integer (op_ptr, 4, byte_order));
+ op_ptr += 4;
+ break;
+ case DW_OP_const4s:
+ ax_const_l (expr, extract_signed_integer (op_ptr, 4, byte_order));
+ op_ptr += 4;
+ break;
+ case DW_OP_const8u:
+ ax_const_l (expr, extract_unsigned_integer (op_ptr, 8, byte_order));
+ op_ptr += 8;
+ break;
+ case DW_OP_const8s:
+ ax_const_l (expr, extract_signed_integer (op_ptr, 8, byte_order));
+ op_ptr += 8;
+ break;
+ case DW_OP_constu:
+ op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
+ ax_const_l (expr, uoffset);
+ break;
+ case DW_OP_consts:
+ op_ptr = read_sleb128 (op_ptr, op_end, &offset);
+ ax_const_l (expr, offset);
+ break;
+
+ case DW_OP_reg0:
+ case DW_OP_reg1:
+ case DW_OP_reg2:
+ case DW_OP_reg3:
+ case DW_OP_reg4:
+ case DW_OP_reg5:
+ case DW_OP_reg6:
+ case DW_OP_reg7:
+ case DW_OP_reg8:
+ case DW_OP_reg9:
+ case DW_OP_reg10:
+ case DW_OP_reg11:
+ case DW_OP_reg12:
+ case DW_OP_reg13:
+ case DW_OP_reg14:
+ case DW_OP_reg15:
+ case DW_OP_reg16:
+ case DW_OP_reg17:
+ case DW_OP_reg18:
+ case DW_OP_reg19:
+ case DW_OP_reg20:
+ case DW_OP_reg21:
+ case DW_OP_reg22:
+ case DW_OP_reg23:
+ case DW_OP_reg24:
+ case DW_OP_reg25:
+ case DW_OP_reg26:
+ case DW_OP_reg27:
+ case DW_OP_reg28:
+ case DW_OP_reg29:
+ case DW_OP_reg30:
+ case DW_OP_reg31:
+ dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
+ loc->u.reg = translate_register (arch, op - DW_OP_reg0);
+ loc->kind = axs_lvalue_register;
+ break;
+
+ case DW_OP_regx:
+ op_ptr = read_uleb128 (op_ptr, op_end, ®);
+ dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
+ loc->u.reg = translate_register (arch, reg);
+ loc->kind = axs_lvalue_register;
+ break;
+
+ case DW_OP_implicit_value:
+ {
+ ULONGEST len;
+
+ op_ptr = read_uleb128 (op_ptr, op_end, &len);
+ if (op_ptr + len > op_end)
+ error (_("DW_OP_implicit_value: too few bytes available."));
+ if (len > sizeof (ULONGEST))
+ error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
+ (int) len);
+
+ ax_const_l (expr, extract_unsigned_integer (op_ptr, len,
+ byte_order));
+ op_ptr += len;
+ dwarf_expr_require_composition (op_ptr, op_end,
+ "DW_OP_implicit_value");
+
+ loc->kind = axs_rvalue;
+ }
+ break;
+
+ case DW_OP_stack_value:
+ dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value");
+ loc->kind = axs_rvalue;
+ break;
+
+ case DW_OP_breg0:
+ case DW_OP_breg1:
+ case DW_OP_breg2:
+ case DW_OP_breg3:
+ case DW_OP_breg4:
+ case DW_OP_breg5:
+ case DW_OP_breg6:
+ case DW_OP_breg7:
+ case DW_OP_breg8:
+ case DW_OP_breg9:
+ case DW_OP_breg10:
+ case DW_OP_breg11:
+ case DW_OP_breg12:
+ case DW_OP_breg13:
+ case DW_OP_breg14:
+ case DW_OP_breg15:
+ case DW_OP_breg16:
+ case DW_OP_breg17:
+ case DW_OP_breg18:
+ case DW_OP_breg19:
+ case DW_OP_breg20:
+ case DW_OP_breg21:
+ case DW_OP_breg22:
+ case DW_OP_breg23:
+ case DW_OP_breg24:
+ case DW_OP_breg25:
+ case DW_OP_breg26:
+ case DW_OP_breg27:
+ case DW_OP_breg28:
+ case DW_OP_breg29:
+ case DW_OP_breg30:
+ case DW_OP_breg31:
+ op_ptr = read_sleb128 (op_ptr, op_end, &offset);
+ i = translate_register (arch, op - DW_OP_breg0);
+ ax_reg (expr, i);
+ if (offset != 0)
+ {
+ ax_const_l (expr, offset);
+ ax_simple (expr, aop_add);
+ }
+ break;
+ case DW_OP_bregx:
+ {
+ op_ptr = read_uleb128 (op_ptr, op_end, ®);
+ op_ptr = read_sleb128 (op_ptr, op_end, &offset);
+ i = translate_register (arch, reg);
+ ax_reg (expr, i);
+ if (offset != 0)
+ {
+ ax_const_l (expr, offset);
+ ax_simple (expr, aop_add);
+ }
+ }
+ break;
+ case DW_OP_fbreg:
+ {
+ const gdb_byte *datastart;
+ size_t datalen;
+ unsigned int before_stack_len;
+ struct block *b;
+ struct symbol *framefunc;
+ LONGEST base_offset = 0;
+
+ b = block_for_pc (expr->scope);
+
+ if (!b)
+ error (_("No block found for address"));
+
+ framefunc = block_linkage_function (b);
+
+ if (!framefunc)
+ error (_("No function found for block"));
+
+ dwarf_expr_frame_base_1 (framefunc, expr->scope,
+ &datastart, &datalen);
+
+ op_ptr = read_sleb128 (op_ptr, op_end, &offset);
+ dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, datastart,
+ datastart + datalen, per_cu);
+
+ if (offset != 0)
+ {
+ ax_const_l (expr, offset);
+ ax_simple (expr, aop_add);
+ }
+
+ loc->kind = axs_lvalue_memory;
+ }
+ break;
+
+ case DW_OP_dup:
+ ax_simple (expr, aop_dup);
+ break;
+
+ case DW_OP_drop:
+ ax_simple (expr, aop_pop);
+ break;
+
+ case DW_OP_pick:
+ offset = *op_ptr++;
+ ax_pick (expr, offset);
+ break;
+
+ case DW_OP_swap:
+ ax_simple (expr, aop_swap);
+ break;
+
+ case DW_OP_over:
+ ax_pick (expr, 1);
+ break;
+
+ case DW_OP_rot:
+ ax_simple (expr, aop_rot);
+ break;
+
+ case DW_OP_deref:
+ case DW_OP_deref_size:
+ {
+ int size;
+
+ if (op == DW_OP_deref_size)
+ size = *op_ptr++;
+ else
+ size = addr_size;
+
+ switch (size)
+ {
+ case 8:
+ ax_simple (expr, aop_ref8);
+ break;
+ case 16:
+ ax_simple (expr, aop_ref16);
+ break;
+ case 32:
+ ax_simple (expr, aop_ref32);
+ break;
+ case 64:
+ ax_simple (expr, aop_ref64);
+ break;
+ default:
+ /* Note that dwarf_stack_op_name will never return
+ NULL here. */
+ error (_("Unsupported size %d in %s"),
+ size, dwarf_stack_op_name (op));
+ }
+ }
+ break;
+
+ case DW_OP_abs:
+ /* Sign extend the operand. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_dup);
+ ax_const_l (expr, 0);
+ ax_simple (expr, aop_less_signed);
+ ax_simple (expr, aop_log_not);
+ i = ax_goto (expr, aop_if_goto);
+ /* We have to emit 0 - X. */
+ ax_const_l (expr, 0);
+ ax_simple (expr, aop_swap);
+ ax_simple (expr, aop_sub);
+ ax_label (expr, i, expr->len);
+ break;
+
+ case DW_OP_neg:
+ /* No need to sign extend here. */
+ ax_const_l (expr, 0);
+ ax_simple (expr, aop_swap);
+ ax_simple (expr, aop_sub);
+ break;
+
+ case DW_OP_not:
+ /* Sign extend the operand. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_bit_not);
+ break;
+
+ case DW_OP_plus_uconst:
+ op_ptr = read_uleb128 (op_ptr, op_end, ®);
+ /* It would be really weird to emit `DW_OP_plus_uconst 0',
+ but we micro-optimize anyhow. */
+ if (reg != 0)
+ {
+ ax_const_l (expr, reg);
+ ax_simple (expr, aop_add);
+ }
+ break;
+
+ case DW_OP_and:
+ ax_simple (expr, aop_bit_and);
+ break;
+
+ case DW_OP_div:
+ /* Sign extend the operands. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_simple (expr, aop_div_signed);
+ break;
+
+ case DW_OP_minus:
+ ax_simple (expr, aop_sub);
+ break;
+
+ case DW_OP_mod:
+ ax_simple (expr, aop_rem_unsigned);
+ break;
+
+ case DW_OP_mul:
+ ax_simple (expr, aop_mul);
+ break;
+
+ case DW_OP_or:
+ ax_simple (expr, aop_bit_or);
+ break;
+
+ case DW_OP_plus:
+ ax_simple (expr, aop_add);
+ break;
+
+ case DW_OP_shl:
+ ax_simple (expr, aop_lsh);
+ break;
+
+ case DW_OP_shr:
+ ax_simple (expr, aop_rsh_unsigned);
+ break;
+
+ case DW_OP_shra:
+ ax_simple (expr, aop_rsh_signed);
+ break;
+
+ case DW_OP_xor:
+ ax_simple (expr, aop_bit_xor);
+ break;
+
+ case DW_OP_le:
+ /* Sign extend the operands. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_ext (expr, addr_size_bits);
+ /* Note no swap here: A <= B is !(B < A). */
+ ax_simple (expr, aop_less_signed);
+ ax_simple (expr, aop_log_not);
+ break;
+
+ case DW_OP_ge:
+ /* Sign extend the operands. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ /* A >= B is !(A < B). */
+ ax_simple (expr, aop_less_signed);
+ ax_simple (expr, aop_log_not);
+ break;
+
+ case DW_OP_eq:
+ /* Sign extend the operands. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_ext (expr, addr_size_bits);
+ /* No need for a second swap here. */
+ ax_simple (expr, aop_equal);
+ break;
+
+ case DW_OP_lt:
+ /* Sign extend the operands. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_simple (expr, aop_less_signed);
+ break;
+
+ case DW_OP_gt:
+ /* Sign extend the operands. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_ext (expr, addr_size_bits);
+ /* Note no swap here: A > B is B < A. */
+ ax_simple (expr, aop_less_signed);
+ break;
+
+ case DW_OP_ne:
+ /* Sign extend the operands. */
+ ax_ext (expr, addr_size_bits);
+ ax_simple (expr, aop_swap);
+ ax_ext (expr, addr_size_bits);
+ /* No need for a swap here. */
+ ax_simple (expr, aop_equal);
+ ax_simple (expr, aop_log_not);
+ break;
+
+ case DW_OP_call_frame_cfa:
+ dwarf2_compile_cfa_to_ax (expr, loc, arch, expr->scope, per_cu);
+ loc->kind = axs_lvalue_memory;
+ break;
+
+ case DW_OP_GNU_push_tls_address:
+ unimplemented (op);
+ break;
+
+ case DW_OP_skip:
+ offset = extract_signed_integer (op_ptr, 2, byte_order);
+ op_ptr += 2;
+ i = ax_goto (expr, aop_goto);
+ VEC_safe_push (int, dw_labels, op_ptr + offset - base);
+ VEC_safe_push (int, patches, i);
+ break;
+
+ case DW_OP_bra:
+ offset = extract_signed_integer (op_ptr, 2, byte_order);
+ op_ptr += 2;
+ /* Zero extend the operand. */
+ ax_zero_ext (expr, addr_size_bits);
+ i = ax_goto (expr, aop_if_goto);
+ VEC_safe_push (int, dw_labels, op_ptr + offset - base);
+ VEC_safe_push (int, patches, i);
+ break;
+
+ case DW_OP_nop:
+ break;
+
+ case DW_OP_piece:
+ case DW_OP_bit_piece:
+ {
+ ULONGEST size, offset;
+
+ if (op_ptr - 1 == previous_piece)
+ error (_("Cannot translate empty pieces to agent expressions"));
+ previous_piece = op_ptr - 1;
+
+ op_ptr = read_uleb128 (op_ptr, op_end, &size);
+ if (op == DW_OP_piece)
+ {
+ size *= 8;
+ offset = 0;
+ }
+ else
+ op_ptr = read_uleb128 (op_ptr, op_end, &offset);
+
+ if (bits_collected + size > 8 * sizeof (LONGEST))
+ error (_("Expression pieces exceed word size"));
+
+ /* Access the bits. */
+ switch (loc->kind)
+ {
+ case axs_lvalue_register:
+ ax_reg (expr, loc->u.reg);
+ break;
+
+ case axs_lvalue_memory:
+ /* Offset the pointer, if needed. */
+ if (offset > 8)
+ {
+ ax_const_l (expr, offset / 8);
+ ax_simple (expr, aop_add);
+ offset %= 8;
+ }
+ access_memory (arch, expr, size);
+ break;
+ }
+
+ /* For a bits-big-endian target, shift up what we already
+ have. For a bits-little-endian target, shift up the
+ new data. Note that there is a potential bug here if
+ the DWARF expression leaves multiple values on the
+ stack. */
+ if (bits_collected > 0)
+ {
+ if (bits_big_endian)
+ {
+ ax_simple (expr, aop_swap);
+ ax_const_l (expr, size);
+ ax_simple (expr, aop_lsh);
+ /* We don't need a second swap here, because
+ aop_bit_or is symmetric. */
+ }
+ else
+ {
+ ax_const_l (expr, size);
+ ax_simple (expr, aop_lsh);
+ }
+ ax_simple (expr, aop_bit_or);
+ }
+
+ bits_collected += size;
+ loc->kind = axs_rvalue;
+ }
+ break;
+
+ case DW_OP_GNU_uninit:
+ unimplemented (op);
+
+ case DW_OP_call2:
+ case DW_OP_call4:
+ {
+ struct dwarf2_locexpr_baton block;
+ int size = (op == DW_OP_call2 ? 2 : 4);
+
+ uoffset = extract_unsigned_integer (op_ptr, size, byte_order);
+ op_ptr += size;
+
+ block = dwarf2_fetch_die_location_block (uoffset, per_cu,
+ get_ax_pc, expr);
+
+ /* DW_OP_call_ref is currently not supported. */
+ gdb_assert (block.per_cu == per_cu);
+
+ dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size,
+ block.data, block.data + block.size,
+ per_cu);
+ }
+ break;
+
+ case DW_OP_call_ref:
+ unimplemented (op);
+
+ default:
+ unimplemented (op);
+ }
+ }
+
+ /* Patch all the branches we emitted. */
+ for (i = 0; i < VEC_length (int, patches); ++i)
+ {
+ int targ = offsets[VEC_index (int, dw_labels, i)];
+ if (targ == -1)
+ internal_error (__FILE__, __LINE__, _("invalid label"));
+ ax_label (expr, VEC_index (int, patches, i), targ);
+ }
+
+ do_cleanups (cleanups);
+}
+
+\f
+/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
+ evaluator to calculate the location. */
+static struct value *
+locexpr_read_variable (struct symbol *symbol, struct frame_info *frame)
+{
+ struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ struct value *val;
+
+ val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data,
+ dlbaton->size, dlbaton->per_cu);
+
+ 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)
+{
+ struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+
+ return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size,
+ dlbaton->per_cu);
+}
+
+/* Return true if DATA points to the end of a piece. END is one past
+ the last byte in the expression. */
- do_cleanups (old_chain);
+static int
+piece_end_p (const gdb_byte *data, const gdb_byte *end)
+{
+ return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece;
+}
- return baton.needs_frame || in_reg;
+/* Helper for locexpr_describe_location_piece that finds the name of a
+ DWARF register. */
+
+static const char *
+locexpr_regname (struct gdbarch *gdbarch, int dwarf_regnum)
+{
+ int regnum;
+
+ regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
+ return gdbarch_register_name (gdbarch, regnum);
}
-static void
-dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
- struct agent_expr *ax, struct axs_value *value,
- gdb_byte *data, int size)
+/* Nicely describe a single piece of a location, returning an updated
+ position in the bytecode sequence. This function cannot recognize
+ all locations; if a location is not recognized, it simply returns
+ DATA. */
+
+static const gdb_byte *
+locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
+ CORE_ADDR addr, struct objfile *objfile,
+ const gdb_byte *data, const gdb_byte *end,
+ unsigned int addr_size)
{
- if (size == 0)
- error (_("Symbol \"%s\" has been optimized out."),
- SYMBOL_PRINT_NAME (symbol));
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
- if (size == 1
- && data[0] >= DW_OP_reg0
- && data[0] <= DW_OP_reg31)
+ if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
{
- value->kind = axs_lvalue_register;
- value->u.reg = data[0] - DW_OP_reg0;
+ fprintf_filtered (stream, _("a variable in $%s"),
+ locexpr_regname (gdbarch, data[0] - DW_OP_reg0));
+ data += 1;
}
else if (data[0] == DW_OP_regx)
{
ULONGEST reg;
- read_uleb128 (data + 1, data + size, ®);
- value->kind = axs_lvalue_register;
- value->u.reg = reg;
+
+ data = read_uleb128 (data + 1, end, ®);
+ fprintf_filtered (stream, _("a variable in $%s"),
+ locexpr_regname (gdbarch, reg));
}
else if (data[0] == DW_OP_fbreg)
{
struct symbol *framefunc;
int frame_reg = 0;
LONGEST frame_offset;
- gdb_byte *buf_end;
- gdb_byte *base_data;
+ const gdb_byte *base_data, *new_data, *save_data = data;
size_t base_size;
LONGEST base_offset = 0;
- b = block_for_pc (ax->scope);
+ new_data = read_sleb128 (data + 1, end, &frame_offset);
+ if (!piece_end_p (new_data, end))
+ return data;
+ data = new_data;
+
+ b = block_for_pc (addr);
if (!b)
- error (_("No block found for address"));
+ error (_("No block found for address for symbol \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
framefunc = block_linkage_function (b);
if (!framefunc)
- error (_("No function found for block"));
+ error (_("No function found for block for symbol \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
- dwarf_expr_frame_base_1 (framefunc, ax->scope,
- &base_data, &base_size);
+ dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size);
- if (base_data[0] >= DW_OP_breg0
- && base_data[0] <= DW_OP_breg31)
+ if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
{
+ const gdb_byte *buf_end;
+
frame_reg = base_data[0] - DW_OP_breg0;
- buf_end = read_sleb128 (base_data + 1, base_data + base_size, &base_offset);
+ buf_end = read_sleb128 (base_data + 1,
+ base_data + base_size, &base_offset);
if (buf_end != base_data + base_size)
- error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
+ error (_("Unexpected opcode after "
+ "DW_OP_breg%u for symbol \"%s\"."),
frame_reg, SYMBOL_PRINT_NAME (symbol));
}
+ else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
+ {
+ /* The frame base is just the register, with no offset. */
+ frame_reg = base_data[0] - DW_OP_reg0;
+ base_offset = 0;
+ }
else
{
/* We don't know what to do with the frame base expression,
so we can't trace this variable; give up. */
- error (_("Cannot generate expression to collect symbol \"%s\"; DWARF 2 encoding not handled"),
- SYMBOL_PRINT_NAME (symbol));
+ return save_data;
}
- buf_end = read_sleb128 (data + 1, data + size, &frame_offset);
- if (buf_end != data + size)
- error (_("Unexpected opcode after DW_OP_fbreg for symbol \"%s\"."),
- SYMBOL_PRINT_NAME (symbol));
-
- ax_reg (ax, frame_reg);
- ax_const_l (ax, base_offset + frame_offset);
- ax_simple (ax, aop_add);
-
- value->kind = axs_lvalue_memory;
+ fprintf_filtered (stream,
+ _("a variable at frame base reg $%s offset %s+%s"),
+ locexpr_regname (gdbarch, frame_reg),
+ plongest (base_offset), plongest (frame_offset));
}
- else if (data[0] >= DW_OP_breg0
- && data[0] <= DW_OP_breg31)
+ else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31
+ && piece_end_p (data, end))
{
- unsigned int reg;
LONGEST offset;
- gdb_byte *buf_end;
- reg = data[0] - DW_OP_breg0;
- buf_end = read_sleb128 (data + 1, data + size, &offset);
- if (buf_end != data + size)
- error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
- reg, SYMBOL_PRINT_NAME (symbol));
+ data = read_sleb128 (data + 1, end, &offset);
+
+ fprintf_filtered (stream,
+ _("a variable at offset %s from base reg $%s"),
+ plongest (offset),
+ locexpr_regname (gdbarch, data[0] - DW_OP_breg0));
+ }
+
+ /* The location expression for a TLS variable looks like this (on a
+ 64-bit LE machine):
+
+ DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
+ (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
- ax_reg (ax, reg);
- ax_const_l (ax, offset);
- ax_simple (ax, aop_add);
+ 0x3 is the encoding for DW_OP_addr, which has an operand as long
+ as the size of an address on the target machine (here is 8
+ bytes). Note that more recent version of GCC emit DW_OP_const4u
+ or DW_OP_const8u, depending on address size, rather than
+ DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
+ The operand represents the offset at which the variable is within
+ the thread local storage. */
- value->kind = axs_lvalue_memory;
+ else if (data + 1 + addr_size < end
+ && (data[0] == DW_OP_addr
+ || (addr_size == 4 && data[0] == DW_OP_const4u)
+ || (addr_size == 8 && data[0] == DW_OP_const8u))
+ && data[1 + addr_size] == DW_OP_GNU_push_tls_address
+ && piece_end_p (data + 2 + addr_size, end))
+ {
+ ULONGEST offset;
+ offset = extract_unsigned_integer (data + 1, addr_size,
+ gdbarch_byte_order (gdbarch));
+
+ fprintf_filtered (stream,
+ _("a thread-local variable at offset 0x%s "
+ "in the thread-local storage for `%s'"),
+ phex_nz (offset, addr_size), objfile->name);
+
+ data += 1 + addr_size + 1;
+ }
+ else if (data[0] >= DW_OP_lit0
+ && data[0] <= DW_OP_lit31
+ && data + 1 < end
+ && data[1] == DW_OP_stack_value)
+ {
+ fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0);
+ data += 2;
}
- else
- error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."),
- data[0], SYMBOL_PRINT_NAME (symbol));
-}
-\f
-/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
- evaluator to calculate the location. */
-static struct value *
-locexpr_read_variable (struct symbol *symbol, struct frame_info *frame)
-{
- struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- struct value *val;
- val = dwarf2_evaluate_loc_desc (symbol, frame, dlbaton->data, dlbaton->size,
- dlbaton->per_cu);
- return val;
+ return data;
}
-/* Return non-zero iff we need a frame to evaluate SYMBOL. */
-static int
-locexpr_read_needs_frame (struct symbol *symbol)
+/* Disassemble an expression, stopping at the end of a piece or at the
+ end of the expression. Returns a pointer to the next unread byte
+ in the input expression. If ALL is nonzero, then this function
+ will keep going until it reaches the end of the expression. */
+
+static const gdb_byte *
+disassemble_dwarf_expression (struct ui_file *stream,
+ struct gdbarch *arch, unsigned int addr_size,
+ int offset_size, const gdb_byte *start,
+ const gdb_byte *data, const gdb_byte *end,
+ int indent, int all,
+ struct dwarf2_per_cu_data *per_cu)
{
- struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size,
- dlbaton->per_cu);
+ while (data < end
+ && (all
+ || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece)))
+ {
+ enum dwarf_location_atom op = *data++;
+ ULONGEST ul;
+ LONGEST l;
+ const char *name;
+
+ name = dwarf_stack_op_name (op);
+
+ if (!name)
+ error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
+ op, (long) (data - 1 - start));
+ fprintf_filtered (stream, " %*ld: %s", indent + 4,
+ (long) (data - 1 - start), name);
+
+ switch (op)
+ {
+ case DW_OP_addr:
+ ul = extract_unsigned_integer (data, addr_size,
+ gdbarch_byte_order (arch));
+ data += addr_size;
+ fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size));
+ break;
+
+ case DW_OP_const1u:
+ ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch));
+ data += 1;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const1s:
+ l = extract_signed_integer (data, 1, gdbarch_byte_order (arch));
+ data += 1;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_const2u:
+ ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const2s:
+ l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_const4u:
+ ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
+ data += 4;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const4s:
+ l = extract_signed_integer (data, 4, gdbarch_byte_order (arch));
+ data += 4;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_const8u:
+ ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch));
+ data += 8;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_const8s:
+ l = extract_signed_integer (data, 8, gdbarch_byte_order (arch));
+ data += 8;
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+ case DW_OP_constu:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+ case DW_OP_consts:
+ data = read_sleb128 (data, end, &l);
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+
+ case DW_OP_reg0:
+ case DW_OP_reg1:
+ case DW_OP_reg2:
+ case DW_OP_reg3:
+ case DW_OP_reg4:
+ case DW_OP_reg5:
+ case DW_OP_reg6:
+ case DW_OP_reg7:
+ case DW_OP_reg8:
+ case DW_OP_reg9:
+ case DW_OP_reg10:
+ case DW_OP_reg11:
+ case DW_OP_reg12:
+ case DW_OP_reg13:
+ case DW_OP_reg14:
+ case DW_OP_reg15:
+ case DW_OP_reg16:
+ case DW_OP_reg17:
+ case DW_OP_reg18:
+ case DW_OP_reg19:
+ case DW_OP_reg20:
+ case DW_OP_reg21:
+ case DW_OP_reg22:
+ case DW_OP_reg23:
+ case DW_OP_reg24:
+ case DW_OP_reg25:
+ case DW_OP_reg26:
+ case DW_OP_reg27:
+ case DW_OP_reg28:
+ case DW_OP_reg29:
+ case DW_OP_reg30:
+ case DW_OP_reg31:
+ fprintf_filtered (stream, " [$%s]",
+ locexpr_regname (arch, op - DW_OP_reg0));
+ break;
+
+ case DW_OP_regx:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s [$%s]", pulongest (ul),
+ locexpr_regname (arch, (int) ul));
+ break;
+
+ case DW_OP_implicit_value:
+ data = read_uleb128 (data, end, &ul);
+ data += ul;
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+
+ case DW_OP_breg0:
+ case DW_OP_breg1:
+ case DW_OP_breg2:
+ case DW_OP_breg3:
+ case DW_OP_breg4:
+ case DW_OP_breg5:
+ case DW_OP_breg6:
+ case DW_OP_breg7:
+ case DW_OP_breg8:
+ case DW_OP_breg9:
+ case DW_OP_breg10:
+ case DW_OP_breg11:
+ case DW_OP_breg12:
+ case DW_OP_breg13:
+ case DW_OP_breg14:
+ case DW_OP_breg15:
+ case DW_OP_breg16:
+ case DW_OP_breg17:
+ case DW_OP_breg18:
+ case DW_OP_breg19:
+ case DW_OP_breg20:
+ case DW_OP_breg21:
+ case DW_OP_breg22:
+ case DW_OP_breg23:
+ case DW_OP_breg24:
+ case DW_OP_breg25:
+ case DW_OP_breg26:
+ case DW_OP_breg27:
+ case DW_OP_breg28:
+ case DW_OP_breg29:
+ case DW_OP_breg30:
+ case DW_OP_breg31:
+ data = read_sleb128 (data, end, &l);
+ fprintf_filtered (stream, " %s [$%s]", plongest (l),
+ locexpr_regname (arch, op - DW_OP_breg0));
+ break;
+
+ case DW_OP_bregx:
+ data = read_uleb128 (data, end, &ul);
+ data = read_sleb128 (data, end, &l);
+ fprintf_filtered (stream, " register %s [$%s] offset %s",
+ pulongest (ul),
+ locexpr_regname (arch, (int) ul),
+ plongest (l));
+ break;
+
+ case DW_OP_fbreg:
+ data = read_sleb128 (data, end, &l);
+ fprintf_filtered (stream, " %s", plongest (l));
+ break;
+
+ case DW_OP_xderef_size:
+ case DW_OP_deref_size:
+ case DW_OP_pick:
+ fprintf_filtered (stream, " %d", *data);
+ ++data;
+ break;
+
+ case DW_OP_plus_uconst:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s", pulongest (ul));
+ break;
+
+ case DW_OP_skip:
+ l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " to %ld",
+ (long) (data + l - start));
+ break;
+
+ case DW_OP_bra:
+ l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " %ld",
+ (long) (data + l - start));
+ break;
+
+ case DW_OP_call2:
+ ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
+ data += 2;
+ fprintf_filtered (stream, " offset %s", phex_nz (ul, 2));
+ break;
+
+ case DW_OP_call4:
+ ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
+ data += 4;
+ fprintf_filtered (stream, " offset %s", phex_nz (ul, 4));
+ break;
+
+ case DW_OP_call_ref:
+ ul = extract_unsigned_integer (data, offset_size,
+ gdbarch_byte_order (arch));
+ data += offset_size;
+ fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size));
+ break;
+
+ case DW_OP_piece:
+ data = read_uleb128 (data, end, &ul);
+ fprintf_filtered (stream, " %s (bytes)", pulongest (ul));
+ break;
+
+ case DW_OP_bit_piece:
+ {
+ ULONGEST offset;
+
+ data = read_uleb128 (data, end, &ul);
+ data = read_uleb128 (data, end, &offset);
+ fprintf_filtered (stream, " size %s offset %s (bits)",
+ pulongest (ul), pulongest (offset));
+ }
+ break;
+
+ case DW_OP_GNU_implicit_pointer:
+ {
+ ul = extract_unsigned_integer (data, offset_size,
+ gdbarch_byte_order (arch));
+ data += offset_size;
+
+ data = read_sleb128 (data, end, &l);
+
+ fprintf_filtered (stream, " DIE %s offset %s",
+ phex_nz (ul, offset_size),
+ plongest (l));
+ }
+ break;
+
+ case DW_OP_GNU_deref_type:
+ {
+ int addr_size = *data++;
+ ULONGEST offset;
+ struct type *type;
+
+ data = read_uleb128 (data, end, &offset);
+ 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),
+ addr_size);
+ }
+ break;
+
+ case DW_OP_GNU_const_type:
+ {
+ ULONGEST type_die;
+ struct type *type;
+
+ data = read_uleb128 (data, end, &type_die);
+ 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));
+ }
+ break;
+
+ case DW_OP_GNU_regval_type:
+ {
+ ULONGEST type_die, reg;
+ struct type *type;
+
+ data = read_uleb128 (data, end, ®);
+ data = read_uleb128 (data, end, &type_die);
+
+ 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),
+ locexpr_regname (arch, reg));
+ }
+ break;
+
+ case DW_OP_GNU_convert:
+ case DW_OP_GNU_reinterpret:
+ {
+ ULONGEST type_die;
+
+ data = read_uleb128 (data, end, &type_die);
+
+ if (type_die == 0)
+ fprintf_filtered (stream, "<0>");
+ else
+ {
+ struct type *type;
+
+ 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));
+ }
+ }
+ 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");
+ }
+
+ return data;
}
-/* Print a natural-language description of SYMBOL to STREAM. */
-static int
-locexpr_describe_location (struct symbol *symbol, struct ui_file *stream)
+/* Describe a single location, which may in turn consist of multiple
+ pieces. */
+
+static void
+locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr,
+ struct ui_file *stream,
+ const gdb_byte *data, int size,
+ struct objfile *objfile, unsigned int addr_size,
+ int offset_size, struct dwarf2_per_cu_data *per_cu)
{
- /* FIXME: be more extensive. */
- struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+ const gdb_byte *end = data + size;
+ int first_piece = 1, bad = 0;
- if (dlbaton->size == 1
- && dlbaton->data[0] >= DW_OP_reg0
- && dlbaton->data[0] <= DW_OP_reg31)
+ while (data < end)
{
- struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
- struct gdbarch *gdbarch = get_objfile_arch (objfile);
- int regno = gdbarch_dwarf2_reg_to_regnum (gdbarch,
- dlbaton->data[0] - DW_OP_reg0);
- fprintf_filtered (stream,
- "a variable in register %s",
- gdbarch_register_name (gdbarch, regno));
- return 1;
- }
+ const gdb_byte *here = data;
+ int disassemble = 1;
- /* The location expression for a TLS variable looks like this (on a
- 64-bit LE machine):
+ if (first_piece)
+ first_piece = 0;
+ else
+ fprintf_filtered (stream, _(", and "));
- DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
- (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
-
- 0x3 is the encoding for DW_OP_addr, which has an operand as long
- as the size of an address on the target machine (here is 8
- bytes). 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
- The operand represents the offset at which the variable is within
- the thread local storage. */
+ if (!dwarf2_always_disassemble)
+ {
+ data = locexpr_describe_location_piece (symbol, stream,
+ addr, objfile,
+ data, end, addr_size);
+ /* If we printed anything, or if we have an empty piece,
+ then don't disassemble. */
+ if (data != here
+ || data[0] == DW_OP_piece
+ || data[0] == DW_OP_bit_piece)
+ disassemble = 0;
+ }
+ if (disassemble)
+ {
+ 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 (dlbaton->size > 1
- && dlbaton->data[dlbaton->size - 1] == DW_OP_GNU_push_tls_address)
- if (dlbaton->data[0] == DW_OP_addr)
- {
- struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
- struct gdbarch *gdbarch = get_objfile_arch (objfile);
- CORE_ADDR offset = dwarf2_read_address (gdbarch,
- &dlbaton->data[1],
- &dlbaton->data[dlbaton->size - 1],
- addr_size);
- fprintf_filtered (stream,
- "a thread-local variable at offset %s in the "
- "thread-local storage for `%s'",
- paddress (gdbarch, offset), objfile->name);
- return 1;
- }
-
+ if (data < end)
+ {
+ int empty = data == here;
+
+ if (disassemble)
+ fprintf_filtered (stream, " ");
+ if (data[0] == DW_OP_piece)
+ {
+ ULONGEST bytes;
+
+ data = read_uleb128 (data + 1, end, &bytes);
+
+ if (empty)
+ fprintf_filtered (stream, _("an empty %s-byte piece"),
+ pulongest (bytes));
+ else
+ fprintf_filtered (stream, _(" [%s-byte piece]"),
+ pulongest (bytes));
+ }
+ else if (data[0] == DW_OP_bit_piece)
+ {
+ ULONGEST bits, offset;
+
+ data = read_uleb128 (data + 1, end, &bits);
+ data = read_uleb128 (data, end, &offset);
+
+ if (empty)
+ fprintf_filtered (stream,
+ _("an empty %s-bit piece"),
+ pulongest (bits));
+ else
+ fprintf_filtered (stream,
+ _(" [%s-bit piece, offset %s bits]"),
+ pulongest (bits), pulongest (offset));
+ }
+ else
+ {
+ bad = 1;
+ break;
+ }
+ }
+ }
- fprintf_filtered (stream,
- "a variable with complex or multiple locations (DWARF2)");
- return 1;
+ if (bad || data > end)
+ error (_("Corrupted DWARF2 expression for \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
}
+/* Print a natural-language description of SYMBOL to STREAM. This
+ version is for a symbol with a single location. */
-/* Describe the location of SYMBOL as an agent value in VALUE, generating
- any necessary bytecode in AX.
+static void
+locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr,
+ struct ui_file *stream)
+{
+ struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
+ unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+ int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
+
+ locexpr_describe_location_1 (symbol, addr, stream,
+ dlbaton->data, dlbaton->size,
+ objfile, addr_size, offset_size,
+ dlbaton->per_cu);
+}
- NOTE drow/2003-02-26: This function is extremely minimal, because
- doing it correctly is extremely complicated and there is no
- publicly available stub with tracepoint support for me to test
- against. When there is one this function should be revisited. */
+/* Describe the location of SYMBOL as an agent value in VALUE, generating
+ any necessary bytecode in AX. */
static void
locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
struct agent_expr *ax, struct axs_value *value)
{
struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
- dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value,
- dlbaton->data, dlbaton->size);
+ if (dlbaton->size == 0)
+ value->optimized_out = 1;
+ else
+ dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size,
+ dlbaton->data, dlbaton->data + dlbaton->size,
+ dlbaton->per_cu);
}
/* The set of location functions used with the DWARF-2 expression
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
{
struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
struct value *val;
- gdb_byte *data;
+ const gdb_byte *data;
size_t size;
+ CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0;
- data = find_location_expression (dlbaton, &size,
- frame ? get_frame_address_in_block (frame)
- : 0);
- if (data == NULL)
- {
- val = allocate_value (SYMBOL_TYPE (symbol));
- VALUE_LVAL (val) = not_lval;
- set_value_optimized_out (val, 1);
- }
- else
- val = dwarf2_evaluate_loc_desc (symbol, frame, data, size,
- dlbaton->per_cu);
+ data = dwarf2_find_location_expression (dlbaton, &size, pc);
+ 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)
return 1;
}
-/* Print a natural-language description of SYMBOL to STREAM. */
-static int
-loclist_describe_location (struct symbol *symbol, struct ui_file *stream)
+/* Print a natural-language description of SYMBOL to STREAM. This
+ version applies when there is a list of different locations, each
+ with a specified address range. */
+
+static void
+loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
+ struct ui_file *stream)
{
- /* FIXME: Could print the entire list of locations. */
- fprintf_filtered (stream, "a variable with multiple locations");
- return 1;
+ struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+ CORE_ADDR low, high;
+ const gdb_byte *loc_ptr, *buf_end;
+ int length, first = 1;
+ struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+ int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
+ int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd);
+ CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
+ /* Adjust base_address for relocatable objects. */
+ CORE_ADDR base_offset = dwarf2_per_cu_text_offset (dlbaton->per_cu);
+ CORE_ADDR base_address = dlbaton->base_address + base_offset;
+
+ loc_ptr = dlbaton->data;
+ buf_end = dlbaton->data + dlbaton->size;
+
+ fprintf_filtered (stream, _("multi-location:\n"));
+
+ /* Iterate through locations until we run out. */
+ while (1)
+ {
+ if (buf_end - loc_ptr < 2 * addr_size)
+ error (_("Corrupted DWARF expression for symbol \"%s\"."),
+ SYMBOL_PRINT_NAME (symbol));
+
+ if (signed_addr_p)
+ low = extract_signed_integer (loc_ptr, addr_size, byte_order);
+ else
+ low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ loc_ptr += addr_size;
+
+ if (signed_addr_p)
+ high = extract_signed_integer (loc_ptr, addr_size, byte_order);
+ else
+ high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+ loc_ptr += addr_size;
+
+ /* A base-address-selection entry. */
+ if ((low & base_mask) == base_mask)
+ {
+ base_address = high + base_offset;
+ fprintf_filtered (stream, _(" Base address %s"),
+ paddress (gdbarch, base_address));
+ continue;
+ }
+
+ /* An end-of-list entry. */
+ if (low == 0 && high == 0)
+ break;
+
+ /* Otherwise, a location expression entry. */
+ low += base_address;
+ high += base_address;
+
+ length = extract_unsigned_integer (loc_ptr, 2, byte_order);
+ loc_ptr += 2;
+
+ /* (It would improve readability to print only the minimum
+ necessary digits of the second number of the range.) */
+ fprintf_filtered (stream, _(" Range %s-%s: "),
+ paddress (gdbarch, low), paddress (gdbarch, high));
+
+ /* Now describe this particular location. */
+ locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length,
+ objfile, addr_size, offset_size,
+ dlbaton->per_cu);
+
+ fprintf_filtered (stream, "\n");
+
+ loc_ptr += length;
+ }
}
/* Describe the location of SYMBOL as an agent value in VALUE, generating
struct agent_expr *ax, struct axs_value *value)
{
struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
- gdb_byte *data;
+ const gdb_byte *data;
size_t size;
+ unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
- data = find_location_expression (dlbaton, &size, ax->scope);
- if (data == NULL)
- error (_("Variable \"%s\" is not available."), SYMBOL_NATURAL_NAME (symbol));
-
- dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, data, size);
+ data = dwarf2_find_location_expression (dlbaton, &size, ax->scope);
+ if (size == 0)
+ value->optimized_out = 1;
+ else
+ dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size,
+ dlbaton->per_cu);
}
/* The set of location functions used with the DWARF-2 expression
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
};
+
+void
+_initialize_dwarf2loc (void)
+{
+ add_setshow_zinteger_cmd ("entry-values", class_maintenance,
+ &entry_values_debug,
+ _("Set entry values and tail call frames "
+ "debugging."),
+ _("Show entry values and tail call frames "
+ "debugging."),
+ _("When non-zero, the process of determining "
+ "parameter values from function entry point "
+ "and tail call frames will be printed."),
+ NULL,
+ show_entry_values_debug,
+ &setdebuglist, &showdebuglist);
+}
projects / deliverable / binutils-gdb.git / blobdiff