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binutils-gdb/gdb/eval.c
Andrew Burgess 6f0dabd46d gdb/x86: handle stap probe arguments in xmm registers 
On x86 machines with xmm register, and with recent versions of
systemtap (and gcc?), it can occur that stap probe arguments will be
placed into xmm registers.

I notice this happening on a current Fedora Rawhide install with the
following package versions installed:

  $ rpm -q glibc systemtap gcc
  glibc-2.35.9000-10.fc37.x86_64
  systemtap-4.7~pre16468670g9f253544-1.fc37.x86_64
  gcc-12.0.1-0.12.fc37.x86_64

If I check the probe data in libc, I see this:

  $ readelf -n /lib64/libc.so.6
  ...
  stapsdt              0x0000004d       NT_STAPSDT (SystemTap probe descriptors)
    Provider: libc
    Name: pthread_start
    Location: 0x0000000000090ac3, Base: 0x00000000001c65c4, Semaphore: 0x0000000000000000
    Arguments: 8@%xmm1 8@1600(%rbx) 8@1608(%rbx)
  stapsdt              0x00000050       NT_STAPSDT (SystemTap probe descriptors)
    Provider: libc
    Name: pthread_create
    Location: 0x00000000000912f1, Base: 0x00000000001c65c4, Semaphore: 0x0000000000000000
    Arguments: 8@%xmm1 8@%r13 8@8(%rsp) 8@16(%rsp)
  ...

Notice that for both of these probes, the first argument is a uint64_t
stored in the xmm1 register.

Unfortunately, if I try to use this probe within GDB, then I can't
view the first argument.  Here's an example session:

  $ gdb $(which gdb)
  (gdb) start
  ...
  (gdb) info probes stap  libc pthread_create
  ...
  (gdb) break *0x00007ffff729e2f1       # Use address of probe.
  (gdb) continue
  ...
  (gdb) p $_probe_arg0
  Invalid cast.

What's going wrong?  If I re-run my session, but this time use 'set
debug stap-expression 1', this is what I see:

  (gdb) set debug stap-expression 1
  (gdb) p $_probe_arg0
  Operation: UNOP_CAST
   Operation: OP_REGISTER
    String: xmm1
   Type: uint64_t
  Operation: UNOP_CAST
   Operation: OP_REGISTER
    String: r13
   Type: uint64_t
  Operation: UNOP_CAST
   Operation: UNOP_IND
    Operation: UNOP_CAST
     Operation: BINOP_ADD
      Operation: OP_LONG
       Type: long
       Constant: 0x0000000000000008
      Operation: OP_REGISTER
       String: rsp
     Type: uint64_t *
   Type: uint64_t
  Operation: UNOP_CAST
   Operation: UNOP_IND
    Operation: UNOP_CAST
     Operation: BINOP_ADD
      Operation: OP_LONG
       Type: long
       Constant: 0x0000000000000010
      Operation: OP_REGISTER
       String: rsp
     Type: uint64_t *
   Type: uint64_t
  Invalid cast.
  (gdb)

The important bit is this:

  Operation: UNOP_CAST
   Operation: OP_REGISTER
    String: xmm1
   Type: uint64_t

Which is where we cast the xmm1 register to uint64_t.  And the final
piece of the puzzle is:

  (gdb) ptype $xmm1
  type = union vec128 {
      v8bf16 v8_bfloat16;
      v4f v4_float;
      v2d v2_double;
      v16i8 v16_int8;
      v8i16 v8_int16;
      v4i32 v4_int32;
      v2i64 v2_int64;
      uint128_t uint128;
  }

So, we are attempting to cast a union type to a scalar type, which is
not supporting in C/C++, and as a consequence GDB's expression
evaluator throws an error when we attempt to do this.

The first approach I considered for solving this problem was to try
and make use of gdbarch_stap_adjust_register.  We already have a
gdbarch method (gdbarch_stap_adjust_register) that allows us to tweak
the name of the register that we access.  Currently only x86
architectures use this to transform things like ax to eax in some
cases.

I wondered, what if we change gdbarch_stap_adjust_register to do more
than just change the register names?  What if this method instead
became gdbarch_stap_read_register.  This new method would return a
operation_up, and would take the register name, and the type we are
trying to read from the register, and return the operation that
actually reads the register.

The default implementation of this method would just use
user_reg_map_name_to_regnum, and then create a register_operation,
like we already do in stap_parse_register_operand.  But, for x86
architectures this method would fist possibly adjust the register
name, then do the default action to read the register.  Finally, for
x86 this method would spot when we were accessing an xmm register,
and, based on the type being pulled from the register, would extract
the correct field from the union.

The benefit of this approach is that it would work with the expression
types that GDB currently supports.  The draw back would be that this
approach would not be very generic.  We'd need code to handle each
sub-field size with an xmm register.  If other architectures started
using vector registers for probe arguments, those architectures would
have to create their own gdbarch_stap_read_register method.  And
finally, the type of the xmm registers comes from the type defined in
the target description, there's a risk that GDB might end up
hard-coding the names of type sub-fields, then if a target uses a
different target description, with different field names for xmm
registers, the stap probes would stop working.

And so, based on all the above draw backs, I rejected this first
approach.

My second plan involves adding a new expression type to GDB called
unop_extract_operation.  This new expression takes a value and a type,
during evaluation the value contents are fetched, and then a new value
is extracted from the value contents (based on type).  This is similar
to the following C expression:

  result_value = *((output_type *) &input_value);

Obviously we can't actually build this expression in this case, as the
input_value is in a register, but hopefully the above makes it clearer
what I'm trying to do.

The benefit of the new expression approach is that this code can be
shared across all architectures, and it doesn't care about sub-field
names within the union type.

The draw-backs that I see are potential future problems if arguments
are not stored within the least significant bytes of the register.
However if/when that becomes an issue we can adapt the
gdbarch_stap_read_register approach to allow architectures to control
how a value is extracted.

For testing, I've extended the existing gdb.base/stap-probe.exp test
to include a function that tries to force an argument into an xmm
register.  Obviously, that will only work on a x86 target, so I've
guarded the new function with an appropriate GCC define.  In the exp
script we use readelf to check if the probe exists, and is using the
xmm register.

If the probe doesn't exist then the associated tests are skipped.

If the probe exists, put isn't using the xmm register (which will
depend on systemtap/gcc versions), then again, the tests are skipped.

Otherwise, we can run the test.  I think the cost of running readelf
is pretty low, so I don't feel too bad making all the non-xmm targets
running this step.

I found that on a Fedora 35 install, with these packages installed, I
was able to run this test and have the probe argument be placed in an
xmm register:

  $ rpm -q systemtap gcc glibc
  systemtap-4.6-4.fc35.x86_64
  gcc-11.2.1-9.fc35.x86_64
  glibc-2.34-7.fc35.x86_64

Finally, as this patch adds a new operation type, then I need to
consider how to generate an agent expression for the new operation
type.

I have kicked the can down the road a bit on this.  In the function
stap_parse_register_operand, I only create a unop_extract_operation in
the case where the register type is non-scalar, this means that in
most cases I don't need to worry about generating an agent expression
at all.

In the xmm register case, when an unop_extract_operation will be
created, I have sketched out how the agent expression could be
handled, however, this code is currently not reached.  When we try to
generate the agent expression to place the xmm register on the stack,
GDB hits this error:

  (gdb) trace -probe-stap test:xmmreg
  Tracepoint 1 at 0x401166
  (gdb) actions
  Enter actions for tracepoint 1, one per line.
  End with a line saying just "end".
  >collect $_probe_arg0
  Value not scalar: cannot be an rvalue.

This is because GDB doesn't currently support placing non-scalar types
on the agent expression evaluation stack.  Solving this is clearly
related to the original problem, but feels a bit like a second
problem.  I'd like to get feedback on whether my approach to solving
the original problem is acceptable or not before I start looking at
how to handle xmm registers within agent expressions.
2022-03-21 14:39:14 +00:00

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/* Evaluate expressions for GDB.
Copyright (C) 1986-2022 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include "expression.h"
#include "target.h"
#include "frame.h"
#include "gdbthread.h"
#include "language.h" /* For CAST_IS_CONVERSION. */
#include "cp-abi.h"
#include "infcall.h"
#include "objc-lang.h"
#include "block.h"
#include "parser-defs.h"
#include "cp-support.h"
#include "ui-out.h"
#include "regcache.h"
#include "user-regs.h"
#include "valprint.h"
#include "gdbsupport/gdb_obstack.h"
#include "objfiles.h"
#include "typeprint.h"
#include <ctype.h>
#include "expop.h"
#include "c-exp.h"
#include "inferior.h"
/* Parse the string EXP as a C expression, evaluate it,
and return the result as a number. */
CORE_ADDR
parse_and_eval_address (const char *exp)
{
expression_up expr = parse_expression (exp);
return value_as_address (evaluate_expression (expr.get ()));
}
/* Like parse_and_eval_address, but treats the value of the expression
as an integer, not an address, returns a LONGEST, not a CORE_ADDR. */
LONGEST
parse_and_eval_long (const char *exp)
{
expression_up expr = parse_expression (exp);
return value_as_long (evaluate_expression (expr.get ()));
}
struct value *
parse_and_eval (const char *exp)
{
expression_up expr = parse_expression (exp);
return evaluate_expression (expr.get ());
}
/* Parse up to a comma (or to a closeparen)
in the string EXPP as an expression, evaluate it, and return the value.
EXPP is advanced to point to the comma. */
struct value *
parse_to_comma_and_eval (const char **expp)
{
expression_up expr = parse_exp_1 (expp, 0, nullptr, 1);
return evaluate_expression (expr.get ());
}
/* See expression.h. */
struct value *
expression::evaluate (struct type *expect_type, enum noside noside)
{
gdb::optional<enable_thread_stack_temporaries> stack_temporaries;
if (target_has_execution () && inferior_ptid != null_ptid
&& language_defn->la_language == language_cplus
&& !thread_stack_temporaries_enabled_p (inferior_thread ()))
stack_temporaries.emplace (inferior_thread ());
struct value *retval = op->evaluate (expect_type, this, noside);
if (stack_temporaries.has_value ()
&& value_in_thread_stack_temporaries (retval, inferior_thread ()))
retval = value_non_lval (retval);
return retval;
}
/* See value.h. */
struct value *
evaluate_expression (struct expression *exp, struct type *expect_type)
{
return exp->evaluate (expect_type, EVAL_NORMAL);
}
/* Evaluate an expression, avoiding all memory references
and getting a value whose type alone is correct. */
struct value *
evaluate_type (struct expression *exp)
{
return exp->evaluate (nullptr, EVAL_AVOID_SIDE_EFFECTS);
}
/* Find the current value of a watchpoint on EXP. Return the value in
*VALP and *RESULTP and the chain of intermediate and final values
in *VAL_CHAIN. RESULTP and VAL_CHAIN may be NULL if the caller does
not need them.
If PRESERVE_ERRORS is true, then exceptions are passed through.
Otherwise, if PRESERVE_ERRORS is false, then if a memory error
occurs while evaluating the expression, *RESULTP will be set to
NULL. *RESULTP may be a lazy value, if the result could not be
read from memory. It is used to determine whether a value is
user-specified (we should watch the whole value) or intermediate
(we should watch only the bit used to locate the final value).
If the final value, or any intermediate value, could not be read
from memory, *VALP will be set to NULL. *VAL_CHAIN will still be
set to any referenced values. *VALP will never be a lazy value.
This is the value which we store in struct breakpoint.
If VAL_CHAIN is non-NULL, the values put into *VAL_CHAIN will be
released from the value chain. If VAL_CHAIN is NULL, all generated
values will be left on the value chain. */
void
fetch_subexp_value (struct expression *exp,
expr::operation *op,
struct value **valp, struct value **resultp,
std::vector<value_ref_ptr> *val_chain,
bool preserve_errors)
{
struct value *mark, *new_mark, *result;
*valp = NULL;
if (resultp)
*resultp = NULL;
if (val_chain)
val_chain->clear ();
/* Evaluate the expression. */
mark = value_mark ();
result = NULL;
try
{
result = op->evaluate (nullptr, exp, EVAL_NORMAL);
}
catch (const gdb_exception &ex)
{
/* Ignore memory errors if we want watchpoints pointing at
inaccessible memory to still be created; otherwise, throw the
error to some higher catcher. */
switch (ex.error)
{
case MEMORY_ERROR:
if (!preserve_errors)
break;
/* Fall through. */
default:
throw;
break;
}
}
new_mark = value_mark ();
if (mark == new_mark)
return;
if (resultp)
*resultp = result;
/* Make sure it's not lazy, so that after the target stops again we
have a non-lazy previous value to compare with. */
if (result != NULL)
{
if (!value_lazy (result))
*valp = result;
else
{
try
{
value_fetch_lazy (result);
*valp = result;
}
catch (const gdb_exception_error &except)
{
}
}
}
if (val_chain)
{
/* Return the chain of intermediate values. We use this to
decide which addresses to watch. */
*val_chain = value_release_to_mark (mark);
}
}
/* Promote value ARG1 as appropriate before performing a unary operation
on this argument.
If the result is not appropriate for any particular language then it
needs to patch this function. */
void
unop_promote (const struct language_defn *language, struct gdbarch *gdbarch,
struct value **arg1)
{
struct type *type1;
*arg1 = coerce_ref (*arg1);
type1 = check_typedef (value_type (*arg1));
if (is_integral_type (type1))
{
switch (language->la_language)
{
default:
/* Perform integral promotion for ANSI C/C++.
If not appropriate for any particular language
it needs to modify this function. */
{
struct type *builtin_int = builtin_type (gdbarch)->builtin_int;
if (TYPE_LENGTH (type1) < TYPE_LENGTH (builtin_int))
*arg1 = value_cast (builtin_int, *arg1);
}
break;
}
}
}
/* Promote values ARG1 and ARG2 as appropriate before performing a binary
operation on those two operands.
If the result is not appropriate for any particular language then it
needs to patch this function. */
void
binop_promote (const struct language_defn *language, struct gdbarch *gdbarch,
struct value **arg1, struct value **arg2)
{
struct type *promoted_type = NULL;
struct type *type1;
struct type *type2;
*arg1 = coerce_ref (*arg1);
*arg2 = coerce_ref (*arg2);
type1 = check_typedef (value_type (*arg1));
type2 = check_typedef (value_type (*arg2));
if ((type1->code () != TYPE_CODE_FLT
&& type1->code () != TYPE_CODE_DECFLOAT
&& !is_integral_type (type1))
|| (type2->code () != TYPE_CODE_FLT
&& type2->code () != TYPE_CODE_DECFLOAT
&& !is_integral_type (type2)))
return;
if (is_fixed_point_type (type1) || is_fixed_point_type (type2))
return;
if (type1->code () == TYPE_CODE_DECFLOAT
|| type2->code () == TYPE_CODE_DECFLOAT)
{
/* No promotion required. */
}
else if (type1->code () == TYPE_CODE_FLT
|| type2->code () == TYPE_CODE_FLT)
{
switch (language->la_language)
{
case language_c:
case language_cplus:
case language_asm:
case language_objc:
case language_opencl:
/* No promotion required. */
break;
default:
/* For other languages the result type is unchanged from gdb
version 6.7 for backward compatibility.
If either arg was long double, make sure that value is also long
double. Otherwise use double. */
if (TYPE_LENGTH (type1) * 8 > gdbarch_double_bit (gdbarch)
|| TYPE_LENGTH (type2) * 8 > gdbarch_double_bit (gdbarch))
promoted_type = builtin_type (gdbarch)->builtin_long_double;
else
promoted_type = builtin_type (gdbarch)->builtin_double;
break;
}
}
else if (type1->code () == TYPE_CODE_BOOL
&& type2->code () == TYPE_CODE_BOOL)
{
/* No promotion required. */
}
else
/* Integral operations here. */
/* FIXME: Also mixed integral/booleans, with result an integer. */
{
const struct builtin_type *builtin = builtin_type (gdbarch);
unsigned int promoted_len1 = TYPE_LENGTH (type1);
unsigned int promoted_len2 = TYPE_LENGTH (type2);
int is_unsigned1 = type1->is_unsigned ();
int is_unsigned2 = type2->is_unsigned ();
unsigned int result_len;
int unsigned_operation;
/* Determine type length and signedness after promotion for
both operands. */
if (promoted_len1 < TYPE_LENGTH (builtin->builtin_int))
{
is_unsigned1 = 0;
promoted_len1 = TYPE_LENGTH (builtin->builtin_int);
}
if (promoted_len2 < TYPE_LENGTH (builtin->builtin_int))
{
is_unsigned2 = 0;
promoted_len2 = TYPE_LENGTH (builtin->builtin_int);
}
if (promoted_len1 > promoted_len2)
{
unsigned_operation = is_unsigned1;
result_len = promoted_len1;
}
else if (promoted_len2 > promoted_len1)
{
unsigned_operation = is_unsigned2;
result_len = promoted_len2;
}
else
{
unsigned_operation = is_unsigned1 || is_unsigned2;
result_len = promoted_len1;
}
switch (language->la_language)
{
case language_c:
case language_cplus:
case language_asm:
case language_objc:
if (result_len <= TYPE_LENGTH (builtin->builtin_int))
{
promoted_type = (unsigned_operation
? builtin->builtin_unsigned_int
: builtin->builtin_int);
}
else if (result_len <= TYPE_LENGTH (builtin->builtin_long))
{
promoted_type = (unsigned_operation
? builtin->builtin_unsigned_long
: builtin->builtin_long);
}
else
{
promoted_type = (unsigned_operation
? builtin->builtin_unsigned_long_long
: builtin->builtin_long_long);
}
break;
case language_opencl:
if (result_len <= TYPE_LENGTH (lookup_signed_typename
(language, "int")))
{
promoted_type =
(unsigned_operation
? lookup_unsigned_typename (language, "int")
: lookup_signed_typename (language, "int"));
}
else if (result_len <= TYPE_LENGTH (lookup_signed_typename
(language, "long")))
{
promoted_type =
(unsigned_operation
? lookup_unsigned_typename (language, "long")
: lookup_signed_typename (language,"long"));
}
break;
default:
/* For other languages the result type is unchanged from gdb
version 6.7 for backward compatibility.
If either arg was long long, make sure that value is also long
long. Otherwise use long. */
if (unsigned_operation)
{
if (result_len > gdbarch_long_bit (gdbarch) / HOST_CHAR_BIT)
promoted_type = builtin->builtin_unsigned_long_long;
else
promoted_type = builtin->builtin_unsigned_long;
}
else
{
if (result_len > gdbarch_long_bit (gdbarch) / HOST_CHAR_BIT)
promoted_type = builtin->builtin_long_long;
else
promoted_type = builtin->builtin_long;
}
break;
}
}
if (promoted_type)
{
/* Promote both operands to common type. */
*arg1 = value_cast (promoted_type, *arg1);
*arg2 = value_cast (promoted_type, *arg2);
}
}
static int
ptrmath_type_p (const struct language_defn *lang, struct type *type)
{
type = check_typedef (type);
if (TYPE_IS_REFERENCE (type))
type = TYPE_TARGET_TYPE (type);
switch (type->code ())
{
case TYPE_CODE_PTR:
case TYPE_CODE_FUNC:
return 1;
case TYPE_CODE_ARRAY:
return type->is_vector () ? 0 : lang->c_style_arrays_p ();
default:
return 0;
}
}
/* Represents a fake method with the given parameter types. This is
used by the parser to construct a temporary "expected" type for
method overload resolution. FLAGS is used as instance flags of the
new type, in order to be able to make the new type represent a
const/volatile overload. */
class fake_method
{
public:
fake_method (type_instance_flags flags,
int num_types, struct type **param_types);
~fake_method ();
/* The constructed type. */
struct type *type () { return &m_type; }
private:
struct type m_type {};
main_type m_main_type {};
};
fake_method::fake_method (type_instance_flags flags,
int num_types, struct type **param_types)
{
struct type *type = &m_type;
TYPE_MAIN_TYPE (type) = &m_main_type;
TYPE_LENGTH (type) = 1;
type->set_code (TYPE_CODE_METHOD);
TYPE_CHAIN (type) = type;
type->set_instance_flags (flags);
if (num_types > 0)
{
if (param_types[num_types - 1] == NULL)
{
--num_types;
type->set_has_varargs (true);
}
else if (check_typedef (param_types[num_types - 1])->code ()
== TYPE_CODE_VOID)
{
--num_types;
/* Caller should have ensured this. */
gdb_assert (num_types == 0);
type->set_is_prototyped (true);
}
}
/* We don't use TYPE_ZALLOC here to allocate space as TYPE is owned by
neither an objfile nor a gdbarch. As a result we must manually
allocate memory for auxiliary fields, and free the memory ourselves
when we are done with it. */
type->set_num_fields (num_types);
type->set_fields
((struct field *) xzalloc (sizeof (struct field) * num_types));
while (num_types-- > 0)
type->field (num_types).set_type (param_types[num_types]);
}
fake_method::~fake_method ()
{
xfree (m_type.fields ());
}
namespace expr
{
value *
type_instance_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
type_instance_flags flags = std::get<0> (m_storage);
std::vector<type *> &types = std::get<1> (m_storage);
fake_method fake_expect_type (flags, types.size (), types.data ());
return std::get<2> (m_storage)->evaluate (fake_expect_type.type (),
exp, noside);
}
}
/* Helper for evaluating an OP_VAR_VALUE. */
value *
evaluate_var_value (enum noside noside, const block *blk, symbol *var)
{
/* JYG: We used to just return value_zero of the symbol type if
we're asked to avoid side effects. Otherwise we return
value_of_variable (...). However I'm not sure if
value_of_variable () has any side effect. We need a full value
object returned here for whatis_exp () to call evaluate_type ()
and then pass the full value to value_rtti_target_type () if we
are dealing with a pointer or reference to a base class and print
object is on. */
struct value *ret = NULL;
try
{
ret = value_of_variable (var, blk);
}
catch (const gdb_exception_error &except)
{
if (noside != EVAL_AVOID_SIDE_EFFECTS)
throw;
ret = value_zero (var->type (), not_lval);
}
return ret;
}
namespace expr
{
value *
var_value_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
symbol *var = std::get<0> (m_storage).symbol;
if (var->type ()->code () == TYPE_CODE_ERROR)
error_unknown_type (var->print_name ());
return evaluate_var_value (noside, std::get<0> (m_storage).block, var);
}
} /* namespace expr */
/* Helper for evaluating an OP_VAR_MSYM_VALUE. */
value *
evaluate_var_msym_value (enum noside noside,
struct objfile *objfile, minimal_symbol *msymbol)
{
CORE_ADDR address;
type *the_type = find_minsym_type_and_address (msymbol, objfile, &address);
if (noside == EVAL_AVOID_SIDE_EFFECTS && !the_type->is_gnu_ifunc ())
return value_zero (the_type, not_lval);
else
return value_at_lazy (the_type, address);
}
/* See expression.h. */
value *
evaluate_subexp_do_call (expression *exp, enum noside noside,
value *callee,
gdb::array_view<value *> argvec,
const char *function_name,
type *default_return_type)
{
if (callee == NULL)
error (_("Cannot evaluate function -- may be inlined"));
if (noside == EVAL_AVOID_SIDE_EFFECTS)
{
/* If the return type doesn't look like a function type,
call an error. This can happen if somebody tries to turn
a variable into a function call. */
type *ftype = value_type (callee);
if (ftype->code () == TYPE_CODE_INTERNAL_FUNCTION)
{
/* We don't know anything about what the internal
function might return, but we have to return
something. */
return value_zero (builtin_type (exp->gdbarch)->builtin_int,
not_lval);
}
else if (ftype->code () == TYPE_CODE_XMETHOD)
{
type *return_type = result_type_of_xmethod (callee, argvec);
if (return_type == NULL)
error (_("Xmethod is missing return type."));
return value_zero (return_type, not_lval);
}
else if (ftype->code () == TYPE_CODE_FUNC
|| ftype->code () == TYPE_CODE_METHOD)
{
if (ftype->is_gnu_ifunc ())
{
CORE_ADDR address = value_address (callee);
type *resolved_type = find_gnu_ifunc_target_type (address);
if (resolved_type != NULL)
ftype = resolved_type;
}
type *return_type = TYPE_TARGET_TYPE (ftype);
if (return_type == NULL)
return_type = default_return_type;
if (return_type == NULL)
error_call_unknown_return_type (function_name);
return allocate_value (return_type);
}
else
error (_("Expression of type other than "
"\"Function returning ...\" used as function"));
}
switch (value_type (callee)->code ())
{
case TYPE_CODE_INTERNAL_FUNCTION:
return call_internal_function (exp->gdbarch, exp->language_defn,
callee, argvec.size (), argvec.data ());
case TYPE_CODE_XMETHOD:
return call_xmethod (callee, argvec);
default:
return call_function_by_hand (callee, default_return_type, argvec);
}
}
namespace expr
{
value *
operation::evaluate_funcall (struct type *expect_type,
struct expression *exp,
enum noside noside,
const char *function_name,
const std::vector<operation_up> &args)
{
std::vector<value *> vals (args.size ());
value *callee = evaluate_with_coercion (exp, noside);
struct type *type = value_type (callee);
if (type->code () == TYPE_CODE_PTR)
type = TYPE_TARGET_TYPE (type);
for (int i = 0; i < args.size (); ++i)
{
if (i < type->num_fields ())
vals[i] = args[i]->evaluate (type->field (i).type (), exp, noside);
else
vals[i] = args[i]->evaluate_with_coercion (exp, noside);
}
return evaluate_subexp_do_call (exp, noside, callee, vals,
function_name, expect_type);
}
value *
var_value_operation::evaluate_funcall (struct type *expect_type,
struct expression *exp,
enum noside noside,
const std::vector<operation_up> &args)
{
if (!overload_resolution
|| exp->language_defn->la_language != language_cplus)
return operation::evaluate_funcall (expect_type, exp, noside, args);
std::vector<value *> argvec (args.size ());
for (int i = 0; i < args.size (); ++i)
argvec[i] = args[i]->evaluate_with_coercion (exp, noside);
struct symbol *symp;
find_overload_match (argvec, NULL, NON_METHOD,
NULL, std::get<0> (m_storage).symbol,
NULL, &symp, NULL, 0, noside);
if (symp->type ()->code () == TYPE_CODE_ERROR)
error_unknown_type (symp->print_name ());
value *callee = evaluate_var_value (noside, std::get<0> (m_storage).block,
symp);
return evaluate_subexp_do_call (exp, noside, callee, argvec,
nullptr, expect_type);
}
value *
scope_operation::evaluate_funcall (struct type *expect_type,
struct expression *exp,
enum noside noside,
const std::vector<operation_up> &args)
{
if (!overload_resolution
|| exp->language_defn->la_language != language_cplus)
return operation::evaluate_funcall (expect_type, exp, noside, args);
/* Unpack it locally so we can properly handle overload
resolution. */
const std::string &name = std::get<1> (m_storage);
struct type *type = std::get<0> (m_storage);
symbol *function = NULL;
const char *function_name = NULL;
std::vector<value *> argvec (1 + args.size ());
if (type->code () == TYPE_CODE_NAMESPACE)
{
function = cp_lookup_symbol_namespace (type->name (),
name.c_str (),
get_selected_block (0),
VAR_DOMAIN).symbol;
if (function == NULL)
error (_("No symbol \"%s\" in namespace \"%s\"."),
name.c_str (), type->name ());
}
else
{
gdb_assert (type->code () == TYPE_CODE_STRUCT
|| type->code () == TYPE_CODE_UNION);
function_name = name.c_str ();
/* We need a properly typed value for method lookup. */
argvec[0] = value_zero (type, lval_memory);
}
for (int i = 0; i < args.size (); ++i)
argvec[i + 1] = args[i]->evaluate_with_coercion (exp, noside);
gdb::array_view<value *> arg_view = argvec;
value *callee = nullptr;
if (function_name != nullptr)
{
int static_memfuncp;
find_overload_match (arg_view, function_name, METHOD,
&argvec[0], nullptr, &callee, nullptr,
&static_memfuncp, 0, noside);
if (!static_memfuncp)
{
/* For the time being, we don't handle this. */
error (_("Call to overloaded function %s requires "
"`this' pointer"),
function_name);
}
arg_view = arg_view.slice (1);
}
else
{
symbol *symp;
arg_view = arg_view.slice (1);
find_overload_match (arg_view, nullptr,
NON_METHOD, nullptr, function,
nullptr, &symp, nullptr, 1, noside);
callee = value_of_variable (symp, get_selected_block (0));
}
return evaluate_subexp_do_call (exp, noside, callee, arg_view,
nullptr, expect_type);
}
value *
structop_member_base::evaluate_funcall (struct type *expect_type,
struct expression *exp,
enum noside noside,
const std::vector<operation_up> &args)
{
/* First, evaluate the structure into lhs. */
value *lhs;
if (opcode () == STRUCTOP_MEMBER)
lhs = std::get<0> (m_storage)->evaluate_for_address (exp, noside);
else
lhs = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
std::vector<value *> vals (args.size () + 1);
gdb::array_view<value *> val_view = vals;
/* If the function is a virtual function, then the aggregate
value (providing the structure) plays its part by providing
the vtable. Otherwise, it is just along for the ride: call
the function directly. */
value *rhs = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
value *callee;
type *a1_type = check_typedef (value_type (rhs));
if (a1_type->code () == TYPE_CODE_METHODPTR)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
callee = value_zero (TYPE_TARGET_TYPE (a1_type), not_lval);
else
callee = cplus_method_ptr_to_value (&lhs, rhs);
vals[0] = lhs;
}
else if (a1_type->code () == TYPE_CODE_MEMBERPTR)
{
struct type *type_ptr
= lookup_pointer_type (TYPE_SELF_TYPE (a1_type));
struct type *target_type_ptr
= lookup_pointer_type (TYPE_TARGET_TYPE (a1_type));
/* Now, convert this value to an address. */
lhs = value_cast (type_ptr, lhs);
long mem_offset = value_as_long (rhs);
callee = value_from_pointer (target_type_ptr,
value_as_long (lhs) + mem_offset);
callee = value_ind (callee);
val_view = val_view.slice (1);
}
else
error (_("Non-pointer-to-member value used in pointer-to-member "
"construct"));
for (int i = 0; i < args.size (); ++i)
vals[i + 1] = args[i]->evaluate_with_coercion (exp, noside);
return evaluate_subexp_do_call (exp, noside, callee, val_view,
nullptr, expect_type);
}
value *
structop_base_operation::evaluate_funcall
(struct type *expect_type, struct expression *exp, enum noside noside,
const std::vector<operation_up> &args)
{
/* Allocate space for the function call arguments, Including space for a
`this' pointer at the start. */
std::vector<value *> vals (args.size () + 1);
/* First, evaluate the structure into vals[0]. */
enum exp_opcode op = opcode ();
if (op == STRUCTOP_STRUCT)
{
/* If v is a variable in a register, and the user types
v.method (), this will produce an error, because v has no
address.
A possible way around this would be to allocate a copy of
the variable on the stack, copy in the contents, call the
function, and copy out the contents. I.e. convert this
from call by reference to call by copy-return (or
whatever it's called). However, this does not work
because it is not the same: the method being called could
stash a copy of the address, and then future uses through
that address (after the method returns) would be expected
to use the variable itself, not some copy of it. */
vals[0] = std::get<0> (m_storage)->evaluate_for_address (exp, noside);
}
else
{
vals[0] = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
/* Check to see if the operator '->' has been overloaded.
If the operator has been overloaded replace vals[0] with the
value returned by the custom operator and continue
evaluation. */
while (unop_user_defined_p (op, vals[0]))
{
struct value *value = nullptr;
try
{
value = value_x_unop (vals[0], op, noside);
}
catch (const gdb_exception_error &except)
{
if (except.error == NOT_FOUND_ERROR)
break;
else
throw;
}
vals[0] = value;
}
}
/* Evaluate the arguments. The '+ 1' here is to allow for the `this'
pointer we placed into vals[0]. */
for (int i = 0; i < args.size (); ++i)
vals[i + 1] = args[i]->evaluate_with_coercion (exp, noside);
/* The array view includes the `this' pointer. */
gdb::array_view<value *> arg_view (vals);
int static_memfuncp;
value *callee;
const char *tstr = std::get<1> (m_storage).c_str ();
if (overload_resolution
&& exp->language_defn->la_language == language_cplus)
{
/* Language is C++, do some overload resolution before
evaluation. */
value *val0 = vals[0];
find_overload_match (arg_view, tstr, METHOD,
&val0, nullptr, &callee, nullptr,
&static_memfuncp, 0, noside);
vals[0] = val0;
}
else
/* Non-C++ case -- or no overload resolution. */
{
struct value *temp = vals[0];
callee = value_struct_elt (&temp, arg_view, tstr,
&static_memfuncp,
op == STRUCTOP_STRUCT
? "structure" : "structure pointer");
/* value_struct_elt updates temp with the correct value of the
``this'' pointer if necessary, so modify it to reflect any
``this'' changes. */
vals[0] = value_from_longest (lookup_pointer_type (value_type (temp)),
value_address (temp)
+ value_embedded_offset (temp));
}
/* Take out `this' if needed. */
if (static_memfuncp)
arg_view = arg_view.slice (1);
return evaluate_subexp_do_call (exp, noside, callee, arg_view,
nullptr, expect_type);
}
} /* namespace expr */
/* Return true if type is integral or reference to integral */
static bool
is_integral_or_integral_reference (struct type *type)
{
if (is_integral_type (type))
return true;
type = check_typedef (type);
return (type != nullptr
&& TYPE_IS_REFERENCE (type)
&& is_integral_type (TYPE_TARGET_TYPE (type)));
}
/* Helper function that implements the body of OP_SCOPE. */
struct value *
eval_op_scope (struct type *expect_type, struct expression *exp,
enum noside noside,
struct type *type, const char *string)
{
struct value *arg1 = value_aggregate_elt (type, string, expect_type,
0, noside);
if (arg1 == NULL)
error (_("There is no field named %s"), string);
return arg1;
}
/* Helper function that implements the body of OP_VAR_ENTRY_VALUE. */
struct value *
eval_op_var_entry_value (struct type *expect_type, struct expression *exp,
enum noside noside, symbol *sym)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return value_zero (sym->type (), not_lval);
if (SYMBOL_COMPUTED_OPS (sym) == NULL
|| SYMBOL_COMPUTED_OPS (sym)->read_variable_at_entry == NULL)
error (_("Symbol \"%s\" does not have any specific entry value"),
sym->print_name ());
struct frame_info *frame = get_selected_frame (NULL);
return SYMBOL_COMPUTED_OPS (sym)->read_variable_at_entry (sym, frame);
}
/* Helper function that implements the body of OP_VAR_MSYM_VALUE. */
struct value *
eval_op_var_msym_value (struct type *expect_type, struct expression *exp,
enum noside noside, bool outermost_p,
bound_minimal_symbol msymbol)
{
value *val = evaluate_var_msym_value (noside, msymbol.objfile,
msymbol.minsym);
struct type *type = value_type (val);
if (type->code () == TYPE_CODE_ERROR
&& (noside != EVAL_AVOID_SIDE_EFFECTS || !outermost_p))
error_unknown_type (msymbol.minsym->print_name ());
return val;
}
/* Helper function that implements the body of OP_FUNC_STATIC_VAR. */
struct value *
eval_op_func_static_var (struct type *expect_type, struct expression *exp,
enum noside noside,
value *func, const char *var)
{
CORE_ADDR addr = value_address (func);
const block *blk = block_for_pc (addr);
struct block_symbol sym = lookup_symbol (var, blk, VAR_DOMAIN, NULL);
if (sym.symbol == NULL)
error (_("No symbol \"%s\" in specified context."), var);
return evaluate_var_value (noside, sym.block, sym.symbol);
}
/* Helper function that implements the body of OP_REGISTER. */
struct value *
eval_op_register (struct type *expect_type, struct expression *exp,
enum noside noside, const char *name)
{
int regno;
struct value *val;
regno = user_reg_map_name_to_regnum (exp->gdbarch,
name, strlen (name));
if (regno == -1)
error (_("Register $%s not available."), name);
/* In EVAL_AVOID_SIDE_EFFECTS mode, we only need to return
a value with the appropriate register type. Unfortunately,
we don't have easy access to the type of user registers.
So for these registers, we fetch the register value regardless
of the evaluation mode. */
if (noside == EVAL_AVOID_SIDE_EFFECTS
&& regno < gdbarch_num_cooked_regs (exp->gdbarch))
val = value_zero (register_type (exp->gdbarch, regno), not_lval);
else
val = value_of_register (regno, get_selected_frame (NULL));
if (val == NULL)
error (_("Value of register %s not available."), name);
else
return val;
}
namespace expr
{
value *
string_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
const std::string &str = std::get<0> (m_storage);
struct type *type = language_string_char_type (exp->language_defn,
exp->gdbarch);
return value_string (str.c_str (), str.size (), type);
}
} /* namespace expr */
/* Helper function that implements the body of OP_OBJC_SELECTOR. */
struct value *
eval_op_objc_selector (struct type *expect_type, struct expression *exp,
enum noside noside,
const char *sel)
{
struct type *selector_type = builtin_type (exp->gdbarch)->builtin_data_ptr;
return value_from_longest (selector_type,
lookup_child_selector (exp->gdbarch, sel));
}
/* A helper function for TERNOP_SLICE. */
struct value *
eval_op_ternop (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *array, struct value *low, struct value *upper)
{
int lowbound = value_as_long (low);
int upperbound = value_as_long (upper);
return value_slice (array, lowbound, upperbound - lowbound + 1);
}
/* A helper function for STRUCTOP_STRUCT. */
struct value *
eval_op_structop_struct (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1, const char *string)
{
struct value *arg3 = value_struct_elt (&arg1, {}, string,
NULL, "structure");
if (noside == EVAL_AVOID_SIDE_EFFECTS)
arg3 = value_zero (value_type (arg3), VALUE_LVAL (arg3));
return arg3;
}
/* A helper function for STRUCTOP_PTR. */
struct value *
eval_op_structop_ptr (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1, const char *string)
{
/* Check to see if operator '->' has been overloaded. If so replace
arg1 with the value returned by evaluating operator->(). */
while (unop_user_defined_p (STRUCTOP_PTR, arg1))
{
struct value *value = NULL;
try
{
value = value_x_unop (arg1, STRUCTOP_PTR, noside);
}
catch (const gdb_exception_error &except)
{
if (except.error == NOT_FOUND_ERROR)
break;
else
throw;
}
arg1 = value;
}
/* JYG: if print object is on we need to replace the base type
with rtti type in order to continue on with successful
lookup of member / method only available in the rtti type. */
{
struct type *arg_type = value_type (arg1);
struct type *real_type;
int full, using_enc;
LONGEST top;
struct value_print_options opts;
get_user_print_options (&opts);
if (opts.objectprint && TYPE_TARGET_TYPE (arg_type)
&& (TYPE_TARGET_TYPE (arg_type)->code () == TYPE_CODE_STRUCT))
{
real_type = value_rtti_indirect_type (arg1, &full, &top,
&using_enc);
if (real_type)
arg1 = value_cast (real_type, arg1);
}
}
struct value *arg3 = value_struct_elt (&arg1, {}, string,
NULL, "structure pointer");
if (noside == EVAL_AVOID_SIDE_EFFECTS)
arg3 = value_zero (value_type (arg3), VALUE_LVAL (arg3));
return arg3;
}
/* A helper function for STRUCTOP_MEMBER. */
struct value *
eval_op_member (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1, struct value *arg2)
{
long mem_offset;
struct value *arg3;
struct type *type = check_typedef (value_type (arg2));
switch (type->code ())
{
case TYPE_CODE_METHODPTR:
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return value_zero (TYPE_TARGET_TYPE (type), not_lval);
else
{
arg2 = cplus_method_ptr_to_value (&arg1, arg2);
gdb_assert (value_type (arg2)->code () == TYPE_CODE_PTR);
return value_ind (arg2);
}
case TYPE_CODE_MEMBERPTR:
/* Now, convert these values to an address. */
arg1 = value_cast_pointers (lookup_pointer_type (TYPE_SELF_TYPE (type)),
arg1, 1);
mem_offset = value_as_long (arg2);
arg3 = value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
value_as_long (arg1) + mem_offset);
return value_ind (arg3);
default:
error (_("non-pointer-to-member value used "
"in pointer-to-member construct"));
}
}
/* A helper function for BINOP_ADD. */
struct value *
eval_op_add (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (BINOP_ADD, arg1, arg2))
return value_x_binop (arg1, arg2, BINOP_ADD, OP_NULL, noside);
else if (ptrmath_type_p (exp->language_defn, value_type (arg1))
&& is_integral_or_integral_reference (value_type (arg2)))
return value_ptradd (arg1, value_as_long (arg2));
else if (ptrmath_type_p (exp->language_defn, value_type (arg2))
&& is_integral_or_integral_reference (value_type (arg1)))
return value_ptradd (arg2, value_as_long (arg1));
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
return value_binop (arg1, arg2, BINOP_ADD);
}
}
/* A helper function for BINOP_SUB. */
struct value *
eval_op_sub (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (BINOP_SUB, arg1, arg2))
return value_x_binop (arg1, arg2, BINOP_SUB, OP_NULL, noside);
else if (ptrmath_type_p (exp->language_defn, value_type (arg1))
&& ptrmath_type_p (exp->language_defn, value_type (arg2)))
{
/* FIXME -- should be ptrdiff_t */
struct type *type = builtin_type (exp->gdbarch)->builtin_long;
return value_from_longest (type, value_ptrdiff (arg1, arg2));
}
else if (ptrmath_type_p (exp->language_defn, value_type (arg1))
&& is_integral_or_integral_reference (value_type (arg2)))
return value_ptradd (arg1, - value_as_long (arg2));
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
return value_binop (arg1, arg2, BINOP_SUB);
}
}
/* Helper function for several different binary operations. */
struct value *
eval_op_binary (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
else
{
/* If EVAL_AVOID_SIDE_EFFECTS and we're dividing by zero,
fudge arg2 to avoid division-by-zero, the caller is
(theoretically) only looking for the type of the result. */
if (noside == EVAL_AVOID_SIDE_EFFECTS
/* ??? Do we really want to test for BINOP_MOD here?
The implementation of value_binop gives it a well-defined
value. */
&& (op == BINOP_DIV
|| op == BINOP_INTDIV
|| op == BINOP_REM
|| op == BINOP_MOD)
&& value_logical_not (arg2))
{
struct value *v_one;
v_one = value_one (value_type (arg2));
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &v_one);
return value_binop (arg1, v_one, op);
}
else
{
/* For shift and integer exponentiation operations,
only promote the first argument. */
if ((op == BINOP_LSH || op == BINOP_RSH || op == BINOP_EXP)
&& is_integral_type (value_type (arg2)))
unop_promote (exp->language_defn, exp->gdbarch, &arg1);
else
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
return value_binop (arg1, arg2, op);
}
}
}
/* A helper function for BINOP_SUBSCRIPT. */
struct value *
eval_op_subscript (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
else
{
/* If the user attempts to subscript something that is not an
array or pointer type (like a plain int variable for example),
then report this as an error. */
arg1 = coerce_ref (arg1);
struct type *type = check_typedef (value_type (arg1));
if (type->code () != TYPE_CODE_ARRAY
&& type->code () != TYPE_CODE_PTR)
{
if (type->name ())
error (_("cannot subscript something of type `%s'"),
type->name ());
else
error (_("cannot subscript requested type"));
}
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return value_zero (TYPE_TARGET_TYPE (type), VALUE_LVAL (arg1));
else
return value_subscript (arg1, value_as_long (arg2));
}
}
/* A helper function for BINOP_EQUAL. */
struct value *
eval_op_equal (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
{
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
}
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
int tem = value_equal (arg1, arg2);
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, (LONGEST) tem);
}
}
/* A helper function for BINOP_NOTEQUAL. */
struct value *
eval_op_notequal (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
{
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
}
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
int tem = value_equal (arg1, arg2);
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, (LONGEST) ! tem);
}
}
/* A helper function for BINOP_LESS. */
struct value *
eval_op_less (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
{
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
}
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
int tem = value_less (arg1, arg2);
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, (LONGEST) tem);
}
}
/* A helper function for BINOP_GTR. */
struct value *
eval_op_gtr (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
{
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
}
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
int tem = value_less (arg2, arg1);
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, (LONGEST) tem);
}
}
/* A helper function for BINOP_GEQ. */
struct value *
eval_op_geq (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
{
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
}
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
int tem = value_less (arg2, arg1) || value_equal (arg1, arg2);
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, (LONGEST) tem);
}
}
/* A helper function for BINOP_LEQ. */
struct value *
eval_op_leq (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (binop_user_defined_p (op, arg1, arg2))
{
return value_x_binop (arg1, arg2, op, OP_NULL, noside);
}
else
{
binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
int tem = value_less (arg1, arg2) || value_equal (arg1, arg2);
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, (LONGEST) tem);
}
}
/* A helper function for BINOP_REPEAT. */
struct value *
eval_op_repeat (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
struct type *type = check_typedef (value_type (arg2));
if (type->code () != TYPE_CODE_INT
&& type->code () != TYPE_CODE_ENUM)
error (_("Non-integral right operand for \"@\" operator."));
if (noside == EVAL_AVOID_SIDE_EFFECTS)
{
return allocate_repeat_value (value_type (arg1),
longest_to_int (value_as_long (arg2)));
}
else
return value_repeat (arg1, longest_to_int (value_as_long (arg2)));
}
/* A helper function for UNOP_PLUS. */
struct value *
eval_op_plus (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (unop_user_defined_p (op, arg1))
return value_x_unop (arg1, op, noside);
else
{
unop_promote (exp->language_defn, exp->gdbarch, &arg1);
return value_pos (arg1);
}
}
/* A helper function for UNOP_NEG. */
struct value *
eval_op_neg (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (unop_user_defined_p (op, arg1))
return value_x_unop (arg1, op, noside);
else
{
unop_promote (exp->language_defn, exp->gdbarch, &arg1);
return value_neg (arg1);
}
}
/* A helper function for UNOP_COMPLEMENT. */
struct value *
eval_op_complement (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (unop_user_defined_p (UNOP_COMPLEMENT, arg1))
return value_x_unop (arg1, UNOP_COMPLEMENT, noside);
else
{
unop_promote (exp->language_defn, exp->gdbarch, &arg1);
return value_complement (arg1);
}
}
/* A helper function for UNOP_LOGICAL_NOT. */
struct value *
eval_op_lognot (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (unop_user_defined_p (op, arg1))
return value_x_unop (arg1, op, noside);
else
{
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, (LONGEST) value_logical_not (arg1));
}
}
/* A helper function for UNOP_IND. */
struct value *
eval_op_ind (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1)
{
struct type *type = check_typedef (value_type (arg1));
if (type->code () == TYPE_CODE_METHODPTR
|| type->code () == TYPE_CODE_MEMBERPTR)
error (_("Attempt to dereference pointer "
"to member without an object"));
if (unop_user_defined_p (UNOP_IND, arg1))
return value_x_unop (arg1, UNOP_IND, noside);
else if (noside == EVAL_AVOID_SIDE_EFFECTS)
{
type = check_typedef (value_type (arg1));
/* If the type pointed to is dynamic then in order to resolve the
dynamic properties we must actually dereference the pointer.
There is a risk that this dereference will have side-effects
in the inferior, but being able to print accurate type
information seems worth the risk. */
if (!type->is_pointer_or_reference ()
|| !is_dynamic_type (TYPE_TARGET_TYPE (type)))
{
if (type->is_pointer_or_reference ()
/* In C you can dereference an array to get the 1st elt. */
|| type->code () == TYPE_CODE_ARRAY)
return value_zero (TYPE_TARGET_TYPE (type),
lval_memory);
else if (type->code () == TYPE_CODE_INT)
/* GDB allows dereferencing an int. */
return value_zero (builtin_type (exp->gdbarch)->builtin_int,
lval_memory);
else
error (_("Attempt to take contents of a non-pointer value."));
}
}
/* Allow * on an integer so we can cast it to whatever we want.
This returns an int, which seems like the most C-like thing to
do. "long long" variables are rare enough that
BUILTIN_TYPE_LONGEST would seem to be a mistake. */
if (type->code () == TYPE_CODE_INT)
return value_at_lazy (builtin_type (exp->gdbarch)->builtin_int,
(CORE_ADDR) value_as_address (arg1));
return value_ind (arg1);
}
/* A helper function for UNOP_ALIGNOF. */
struct value *
eval_op_alignof (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1)
{
struct type *type = value_type (arg1);
/* FIXME: This should be size_t. */
struct type *size_type = builtin_type (exp->gdbarch)->builtin_int;
ULONGEST align = type_align (type);
if (align == 0)
error (_("could not determine alignment of type"));
return value_from_longest (size_type, align);
}
/* A helper function for UNOP_MEMVAL. */
struct value *
eval_op_memval (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1, struct type *type)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return value_zero (type, lval_memory);
else
return value_at_lazy (type, value_as_address (arg1));
}
/* A helper function for UNOP_PREINCREMENT. */
struct value *
eval_op_preinc (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return arg1;
else if (unop_user_defined_p (op, arg1))
{
return value_x_unop (arg1, op, noside);
}
else
{
struct value *arg2;
if (ptrmath_type_p (exp->language_defn, value_type (arg1)))
arg2 = value_ptradd (arg1, 1);
else
{
struct value *tmp = arg1;
arg2 = value_one (value_type (arg1));
binop_promote (exp->language_defn, exp->gdbarch, &tmp, &arg2);
arg2 = value_binop (tmp, arg2, BINOP_ADD);
}
return value_assign (arg1, arg2);
}
}
/* A helper function for UNOP_PREDECREMENT. */
struct value *
eval_op_predec (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return arg1;
else if (unop_user_defined_p (op, arg1))
{
return value_x_unop (arg1, op, noside);
}
else
{
struct value *arg2;
if (ptrmath_type_p (exp->language_defn, value_type (arg1)))
arg2 = value_ptradd (arg1, -1);
else
{
struct value *tmp = arg1;
arg2 = value_one (value_type (arg1));
binop_promote (exp->language_defn, exp->gdbarch, &tmp, &arg2);
arg2 = value_binop (tmp, arg2, BINOP_SUB);
}
return value_assign (arg1, arg2);
}
}
/* A helper function for UNOP_POSTINCREMENT. */
struct value *
eval_op_postinc (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return arg1;
else if (unop_user_defined_p (op, arg1))
{
return value_x_unop (arg1, op, noside);
}
else
{
struct value *arg3 = value_non_lval (arg1);
struct value *arg2;
if (ptrmath_type_p (exp->language_defn, value_type (arg1)))
arg2 = value_ptradd (arg1, 1);
else
{
struct value *tmp = arg1;
arg2 = value_one (value_type (arg1));
binop_promote (exp->language_defn, exp->gdbarch, &tmp, &arg2);
arg2 = value_binop (tmp, arg2, BINOP_ADD);
}
value_assign (arg1, arg2);
return arg3;
}
}
/* A helper function for UNOP_POSTDECREMENT. */
struct value *
eval_op_postdec (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return arg1;
else if (unop_user_defined_p (op, arg1))
{
return value_x_unop (arg1, op, noside);
}
else
{
struct value *arg3 = value_non_lval (arg1);
struct value *arg2;
if (ptrmath_type_p (exp->language_defn, value_type (arg1)))
arg2 = value_ptradd (arg1, -1);
else
{
struct value *tmp = arg1;
arg2 = value_one (value_type (arg1));
binop_promote (exp->language_defn, exp->gdbarch, &tmp, &arg2);
arg2 = value_binop (tmp, arg2, BINOP_SUB);
}
value_assign (arg1, arg2);
return arg3;
}
}
/* A helper function for OP_TYPE. */
struct value *
eval_op_type (struct type *expect_type, struct expression *exp,
enum noside noside, struct type *type)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return allocate_value (type);
else
error (_("Attempt to use a type name as an expression"));
}
/* A helper function for BINOP_ASSIGN_MODIFY. */
struct value *
eval_binop_assign_modify (struct type *expect_type, struct expression *exp,
enum noside noside, enum exp_opcode op,
struct value *arg1, struct value *arg2)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return arg1;
if (binop_user_defined_p (op, arg1, arg2))
return value_x_binop (arg1, arg2, BINOP_ASSIGN_MODIFY, op, noside);
else if (op == BINOP_ADD && ptrmath_type_p (exp->language_defn,
value_type (arg1))
&& is_integral_type (value_type (arg2)))
arg2 = value_ptradd (arg1, value_as_long (arg2));
else if (op == BINOP_SUB && ptrmath_type_p (exp->language_defn,
value_type (arg1))
&& is_integral_type (value_type (arg2)))
arg2 = value_ptradd (arg1, - value_as_long (arg2));
else
{
struct value *tmp = arg1;
/* For shift and integer exponentiation operations,
only promote the first argument. */
if ((op == BINOP_LSH || op == BINOP_RSH || op == BINOP_EXP)
&& is_integral_type (value_type (arg2)))
unop_promote (exp->language_defn, exp->gdbarch, &tmp);
else
binop_promote (exp->language_defn, exp->gdbarch, &tmp, &arg2);
arg2 = value_binop (tmp, arg2, op);
}
return value_assign (arg1, arg2);
}
/* Note that ARGS needs 2 empty slots up front and must end with a
null pointer. */
static struct value *
eval_op_objc_msgcall (struct type *expect_type, struct expression *exp,
enum noside noside, CORE_ADDR selector,
value *target, gdb::array_view<value *> args)
{
CORE_ADDR responds_selector = 0;
CORE_ADDR method_selector = 0;
int struct_return = 0;
struct value *msg_send = NULL;
struct value *msg_send_stret = NULL;
int gnu_runtime = 0;
struct value *method = NULL;
struct value *called_method = NULL;
struct type *selector_type = NULL;
struct type *long_type;
struct type *type;
struct value *ret = NULL;
CORE_ADDR addr = 0;
value *argvec[5];
long_type = builtin_type (exp->gdbarch)->builtin_long;
selector_type = builtin_type (exp->gdbarch)->builtin_data_ptr;
if (value_as_long (target) == 0)
return value_from_longest (long_type, 0);
if (lookup_minimal_symbol ("objc_msg_lookup", 0, 0).minsym)
gnu_runtime = 1;
/* Find the method dispatch (Apple runtime) or method lookup
(GNU runtime) function for Objective-C. These will be used
to lookup the symbol information for the method. If we
can't find any symbol information, then we'll use these to
call the method, otherwise we can call the method
directly. The msg_send_stret function is used in the special
case of a method that returns a structure (Apple runtime
only). */
if (gnu_runtime)
{
type = selector_type;
type = lookup_function_type (type);
type = lookup_pointer_type (type);
type = lookup_function_type (type);
type = lookup_pointer_type (type);
msg_send = find_function_in_inferior ("objc_msg_lookup", NULL);
msg_send_stret
= find_function_in_inferior ("objc_msg_lookup", NULL);
msg_send = value_from_pointer (type, value_as_address (msg_send));
msg_send_stret = value_from_pointer (type,
value_as_address (msg_send_stret));
}
else
{
msg_send = find_function_in_inferior ("objc_msgSend", NULL);
/* Special dispatcher for methods returning structs. */
msg_send_stret
= find_function_in_inferior ("objc_msgSend_stret", NULL);
}
/* Verify the target object responds to this method. The
standard top-level 'Object' class uses a different name for
the verification method than the non-standard, but more
often used, 'NSObject' class. Make sure we check for both. */
responds_selector
= lookup_child_selector (exp->gdbarch, "respondsToSelector:");
if (responds_selector == 0)
responds_selector
= lookup_child_selector (exp->gdbarch, "respondsTo:");
if (responds_selector == 0)
error (_("no 'respondsTo:' or 'respondsToSelector:' method"));
method_selector
= lookup_child_selector (exp->gdbarch, "methodForSelector:");
if (method_selector == 0)
method_selector
= lookup_child_selector (exp->gdbarch, "methodFor:");
if (method_selector == 0)
error (_("no 'methodFor:' or 'methodForSelector:' method"));
/* Call the verification method, to make sure that the target
class implements the desired method. */
argvec[0] = msg_send;
argvec[1] = target;
argvec[2] = value_from_longest (long_type, responds_selector);
argvec[3] = value_from_longest (long_type, selector);
argvec[4] = 0;
ret = call_function_by_hand (argvec[0], NULL, {argvec + 1, 3});
if (gnu_runtime)
{
/* Function objc_msg_lookup returns a pointer. */
argvec[0] = ret;
ret = call_function_by_hand (argvec[0], NULL, {argvec + 1, 3});
}
if (value_as_long (ret) == 0)
error (_("Target does not respond to this message selector."));
/* Call "methodForSelector:" method, to get the address of a
function method that implements this selector for this
class. If we can find a symbol at that address, then we
know the return type, parameter types etc. (that's a good
thing). */
argvec[0] = msg_send;
argvec[1] = target;
argvec[2] = value_from_longest (long_type, method_selector);
argvec[3] = value_from_longest (long_type, selector);
argvec[4] = 0;
ret = call_function_by_hand (argvec[0], NULL, {argvec + 1, 3});
if (gnu_runtime)
{
argvec[0] = ret;
ret = call_function_by_hand (argvec[0], NULL, {argvec + 1, 3});
}
/* ret should now be the selector. */
addr = value_as_long (ret);
if (addr)
{
struct symbol *sym = NULL;
/* The address might point to a function descriptor;
resolve it to the actual code address instead. */
addr = gdbarch_convert_from_func_ptr_addr
(exp->gdbarch, addr, current_inferior ()->top_target ());
/* Is it a high_level symbol? */
sym = find_pc_function (addr);
if (sym != NULL)
method = value_of_variable (sym, 0);
}
/* If we found a method with symbol information, check to see
if it returns a struct. Otherwise assume it doesn't. */
if (method)
{
CORE_ADDR funaddr;
struct type *val_type;
funaddr = find_function_addr (method, &val_type);
block_for_pc (funaddr);
val_type = check_typedef (val_type);
if ((val_type == NULL)
|| (val_type->code () == TYPE_CODE_ERROR))
{
if (expect_type != NULL)
val_type = expect_type;
}
struct_return = using_struct_return (exp->gdbarch, method,
val_type);
}
else if (expect_type != NULL)
{
struct_return = using_struct_return (exp->gdbarch, NULL,
check_typedef (expect_type));
}
/* Found a function symbol. Now we will substitute its
value in place of the message dispatcher (obj_msgSend),
so that we call the method directly instead of thru
the dispatcher. The main reason for doing this is that
we can now evaluate the return value and parameter values
according to their known data types, in case we need to
do things like promotion, dereferencing, special handling
of structs and doubles, etc.
We want to use the type signature of 'method', but still
jump to objc_msgSend() or objc_msgSend_stret() to better
mimic the behavior of the runtime. */
if (method)
{
if (value_type (method)->code () != TYPE_CODE_FUNC)
error (_("method address has symbol information "
"with non-function type; skipping"));
/* Create a function pointer of the appropriate type, and
replace its value with the value of msg_send or
msg_send_stret. We must use a pointer here, as
msg_send and msg_send_stret are of pointer type, and
the representation may be different on systems that use
function descriptors. */
if (struct_return)
called_method
= value_from_pointer (lookup_pointer_type (value_type (method)),
value_as_address (msg_send_stret));
else
called_method
= value_from_pointer (lookup_pointer_type (value_type (method)),
value_as_address (msg_send));
}
else
{
if (struct_return)
called_method = msg_send_stret;
else
called_method = msg_send;
}
if (noside == EVAL_AVOID_SIDE_EFFECTS)
{
/* If the return type doesn't look like a function type,
call an error. This can happen if somebody tries to
turn a variable into a function call. This is here
because people often want to call, eg, strcmp, which
gdb doesn't know is a function. If gdb isn't asked for
it's opinion (ie. through "whatis"), it won't offer
it. */
struct type *callee_type = value_type (called_method);
if (callee_type && callee_type->code () == TYPE_CODE_PTR)
callee_type = TYPE_TARGET_TYPE (callee_type);
callee_type = TYPE_TARGET_TYPE (callee_type);
if (callee_type)
{
if ((callee_type->code () == TYPE_CODE_ERROR) && expect_type)
return allocate_value (expect_type);
else
return allocate_value (callee_type);
}
else
error (_("Expression of type other than "
"\"method returning ...\" used as a method"));
}
/* Now depending on whether we found a symbol for the method,
we will either call the runtime dispatcher or the method
directly. */
args[0] = target;
args[1] = value_from_longest (long_type, selector);
if (gnu_runtime && (method != NULL))
{
/* Function objc_msg_lookup returns a pointer. */
struct type *tem_type = value_type (called_method);
tem_type = lookup_pointer_type (lookup_function_type (tem_type));
deprecated_set_value_type (called_method, tem_type);
called_method = call_function_by_hand (called_method, NULL, args);
}
return call_function_by_hand (called_method, NULL, args);
}
/* Helper function for MULTI_SUBSCRIPT. */
static struct value *
eval_multi_subscript (struct type *expect_type, struct expression *exp,
enum noside noside, value *arg1,
gdb::array_view<value *> args)
{
for (value *arg2 : args)
{
if (binop_user_defined_p (MULTI_SUBSCRIPT, arg1, arg2))
{
arg1 = value_x_binop (arg1, arg2, MULTI_SUBSCRIPT, OP_NULL, noside);
}
else
{
arg1 = coerce_ref (arg1);
struct type *type = check_typedef (value_type (arg1));
switch (type->code ())
{
case TYPE_CODE_PTR:
case TYPE_CODE_ARRAY:
case TYPE_CODE_STRING:
arg1 = value_subscript (arg1, value_as_long (arg2));
break;
default:
if (type->name ())
error (_("cannot subscript something of type `%s'"),
type->name ());
else
error (_("cannot subscript requested type"));
}
}
}
return (arg1);
}
namespace expr
{
value *
objc_msgcall_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
enum noside sub_no_side = EVAL_NORMAL;
struct type *selector_type = builtin_type (exp->gdbarch)->builtin_data_ptr;
if (noside == EVAL_AVOID_SIDE_EFFECTS)
sub_no_side = EVAL_NORMAL;
else
sub_no_side = noside;
value *target
= std::get<1> (m_storage)->evaluate (selector_type, exp, sub_no_side);
if (value_as_long (target) == 0)
sub_no_side = EVAL_AVOID_SIDE_EFFECTS;
else
sub_no_side = noside;
std::vector<operation_up> &args = std::get<2> (m_storage);
value **argvec = XALLOCAVEC (struct value *, args.size () + 3);
argvec[0] = nullptr;
argvec[1] = nullptr;
for (int i = 0; i < args.size (); ++i)
argvec[i + 2] = args[i]->evaluate_with_coercion (exp, sub_no_side);
argvec[args.size () + 2] = nullptr;
return eval_op_objc_msgcall (expect_type, exp, noside, std::
get<0> (m_storage), target,
gdb::make_array_view (argvec,
args.size () + 3));
}
value *
multi_subscript_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
value *arg1 = std::get<0> (m_storage)->evaluate_with_coercion (exp, noside);
std::vector<operation_up> &values = std::get<1> (m_storage);
value **argvec = XALLOCAVEC (struct value *, values.size ());
for (int ix = 0; ix < values.size (); ++ix)
argvec[ix] = values[ix]->evaluate_with_coercion (exp, noside);
return eval_multi_subscript (expect_type, exp, noside, arg1,
gdb::make_array_view (argvec, values.size ()));
}
value *
logical_and_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
value *arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
value *arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp,
EVAL_AVOID_SIDE_EFFECTS);
if (binop_user_defined_p (BINOP_LOGICAL_AND, arg1, arg2))
{
arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
return value_x_binop (arg1, arg2, BINOP_LOGICAL_AND, OP_NULL, noside);
}
else
{
bool tem = value_logical_not (arg1);
if (!tem)
{
arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
tem = value_logical_not (arg2);
}
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, !tem);
}
}
value *
logical_or_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
value *arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
value *arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp,
EVAL_AVOID_SIDE_EFFECTS);
if (binop_user_defined_p (BINOP_LOGICAL_OR, arg1, arg2))
{
arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
return value_x_binop (arg1, arg2, BINOP_LOGICAL_OR, OP_NULL, noside);
}
else
{
bool tem = value_logical_not (arg1);
if (tem)
{
arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
tem = value_logical_not (arg2);
}
struct type *type = language_bool_type (exp->language_defn,
exp->gdbarch);
return value_from_longest (type, !tem);
}
}
value *
adl_func_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
std::vector<operation_up> &arg_ops = std::get<2> (m_storage);
std::vector<value *> args (arg_ops.size ());
for (int i = 0; i < arg_ops.size (); ++i)
args[i] = arg_ops[i]->evaluate_with_coercion (exp, noside);
struct symbol *symp;
find_overload_match (args, std::get<0> (m_storage).c_str (),
NON_METHOD,
nullptr, nullptr,
nullptr, &symp, nullptr, 0, noside);
if (symp->type ()->code () == TYPE_CODE_ERROR)
error_unknown_type (symp->print_name ());
value *callee = evaluate_var_value (noside, std::get<1> (m_storage), symp);
return evaluate_subexp_do_call (exp, noside, callee, args,
nullptr, expect_type);
}
/* This function evaluates brace-initializers (in C/C++) for
structure types. */
struct value *
array_operation::evaluate_struct_tuple (struct value *struct_val,
struct expression *exp,
enum noside noside, int nargs)
{
const std::vector<operation_up> &in_args = std::get<2> (m_storage);
struct type *struct_type = check_typedef (value_type (struct_val));
struct type *field_type;
int fieldno = -1;
int idx = 0;
while (--nargs >= 0)
{
struct value *val = NULL;
int bitpos, bitsize;
bfd_byte *addr;
fieldno++;
/* Skip static fields. */
while (fieldno < struct_type->num_fields ()
&& field_is_static (&struct_type->field (fieldno)))
fieldno++;
if (fieldno >= struct_type->num_fields ())
error (_("too many initializers"));
field_type = struct_type->field (fieldno).type ();
if (field_type->code () == TYPE_CODE_UNION
&& struct_type->field (fieldno).name ()[0] == '0')
error (_("don't know which variant you want to set"));
/* Here, struct_type is the type of the inner struct,
while substruct_type is the type of the inner struct.
These are the same for normal structures, but a variant struct
contains anonymous union fields that contain substruct fields.
The value fieldno is the index of the top-level (normal or
anonymous union) field in struct_field, while the value
subfieldno is the index of the actual real (named inner) field
in substruct_type. */
field_type = struct_type->field (fieldno).type ();
if (val == 0)
val = in_args[idx++]->evaluate (field_type, exp, noside);
/* Now actually set the field in struct_val. */
/* Assign val to field fieldno. */
if (value_type (val) != field_type)
val = value_cast (field_type, val);
bitsize = TYPE_FIELD_BITSIZE (struct_type, fieldno);
bitpos = struct_type->field (fieldno).loc_bitpos ();
addr = value_contents_writeable (struct_val).data () + bitpos / 8;
if (bitsize)
modify_field (struct_type, addr,
value_as_long (val), bitpos % 8, bitsize);
else
memcpy (addr, value_contents (val).data (),
TYPE_LENGTH (value_type (val)));
}
return struct_val;
}
value *
array_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
int tem;
int tem2 = std::get<0> (m_storage);
int tem3 = std::get<1> (m_storage);
const std::vector<operation_up> &in_args = std::get<2> (m_storage);
int nargs = tem3 - tem2 + 1;
struct type *type = expect_type ? check_typedef (expect_type) : nullptr;
if (expect_type != nullptr
&& type->code () == TYPE_CODE_STRUCT)
{
struct value *rec = allocate_value (expect_type);
memset (value_contents_raw (rec).data (), '\0', TYPE_LENGTH (type));
return evaluate_struct_tuple (rec, exp, noside, nargs);
}
if (expect_type != nullptr
&& type->code () == TYPE_CODE_ARRAY)
{
struct type *range_type = type->index_type ();
struct type *element_type = TYPE_TARGET_TYPE (type);
struct value *array = allocate_value (expect_type);
int element_size = TYPE_LENGTH (check_typedef (element_type));
LONGEST low_bound, high_bound, index;
if (!get_discrete_bounds (range_type, &low_bound, &high_bound))
{
low_bound = 0;
high_bound = (TYPE_LENGTH (type) / element_size) - 1;
}
index = low_bound;
memset (value_contents_raw (array).data (), 0, TYPE_LENGTH (expect_type));
for (tem = nargs; --nargs >= 0;)
{
struct value *element;
element = in_args[index - low_bound]->evaluate (element_type,
exp, noside);
if (value_type (element) != element_type)
element = value_cast (element_type, element);
if (index > high_bound)
/* To avoid memory corruption. */
error (_("Too many array elements"));
memcpy (value_contents_raw (array).data ()
+ (index - low_bound) * element_size,
value_contents (element).data (),
element_size);
index++;
}
return array;
}
if (expect_type != nullptr
&& type->code () == TYPE_CODE_SET)
{
struct value *set = allocate_value (expect_type);
gdb_byte *valaddr = value_contents_raw (set).data ();
struct type *element_type = type->index_type ();
struct type *check_type = element_type;
LONGEST low_bound, high_bound;
/* Get targettype of elementtype. */
while (check_type->code () == TYPE_CODE_RANGE
|| check_type->code () == TYPE_CODE_TYPEDEF)
check_type = TYPE_TARGET_TYPE (check_type);
if (!get_discrete_bounds (element_type, &low_bound, &high_bound))
error (_("(power)set type with unknown size"));
memset (valaddr, '\0', TYPE_LENGTH (type));
int idx = 0;
for (tem = 0; tem < nargs; tem++)
{
LONGEST range_low, range_high;
struct type *range_low_type, *range_high_type;
struct value *elem_val;
elem_val = in_args[idx++]->evaluate (element_type, exp, noside);
range_low_type = range_high_type = value_type (elem_val);
range_low = range_high = value_as_long (elem_val);
/* Check types of elements to avoid mixture of elements from
different types. Also check if type of element is "compatible"
with element type of powerset. */
if (range_low_type->code () == TYPE_CODE_RANGE)
range_low_type = TYPE_TARGET_TYPE (range_low_type);
if (range_high_type->code () == TYPE_CODE_RANGE)
range_high_type = TYPE_TARGET_TYPE (range_high_type);
if ((range_low_type->code () != range_high_type->code ())
|| (range_low_type->code () == TYPE_CODE_ENUM
&& (range_low_type != range_high_type)))
/* different element modes. */
error (_("POWERSET tuple elements of different mode"));
if ((check_type->code () != range_low_type->code ())
|| (check_type->code () == TYPE_CODE_ENUM
&& range_low_type != check_type))
error (_("incompatible POWERSET tuple elements"));
if (range_low > range_high)
{
warning (_("empty POWERSET tuple range"));
continue;
}
if (range_low < low_bound || range_high > high_bound)
error (_("POWERSET tuple element out of range"));
range_low -= low_bound;
range_high -= low_bound;
for (; range_low <= range_high; range_low++)
{
int bit_index = (unsigned) range_low % TARGET_CHAR_BIT;
if (gdbarch_byte_order (exp->gdbarch) == BFD_ENDIAN_BIG)
bit_index = TARGET_CHAR_BIT - 1 - bit_index;
valaddr[(unsigned) range_low / TARGET_CHAR_BIT]
|= 1 << bit_index;
}
}
return set;
}
value **argvec = XALLOCAVEC (struct value *, nargs);
for (tem = 0; tem < nargs; tem++)
{
/* Ensure that array expressions are coerced into pointer
objects. */
argvec[tem] = in_args[tem]->evaluate_with_coercion (exp, noside);
}
return value_array (tem2, tem3, argvec);
}
value *
unop_extract_operation::evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
value *old_value = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
struct type *type = get_type ();
if (TYPE_LENGTH (type) > TYPE_LENGTH (value_type (old_value)))
error (_("length type is larger than the value type"));
struct value *result = allocate_value (type);
value_contents_copy (result, 0, old_value, 0, TYPE_LENGTH (type));
return result;
}
}
/* Helper for evaluate_subexp_for_address. */
static value *
evaluate_subexp_for_address_base (struct expression *exp, enum noside noside,
value *x)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
{
struct type *type = check_typedef (value_type (x));
if (TYPE_IS_REFERENCE (type))
return value_zero (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
not_lval);
else if (VALUE_LVAL (x) == lval_memory || value_must_coerce_to_target (x))
return value_zero (lookup_pointer_type (value_type (x)),
not_lval);
else
error (_("Attempt to take address of "
"value not located in memory."));
}
return value_addr (x);
}
namespace expr
{
value *
operation::evaluate_for_cast (struct type *expect_type,
struct expression *exp,
enum noside noside)
{
value *val = evaluate (expect_type, exp, noside);
return value_cast (expect_type, val);
}
value *
operation::evaluate_for_address (struct expression *exp, enum noside noside)
{
value *val = evaluate (nullptr, exp, noside);
return evaluate_subexp_for_address_base (exp, noside, val);
}
value *
scope_operation::evaluate_for_address (struct expression *exp,
enum noside noside)
{
value *x = value_aggregate_elt (std::get<0> (m_storage),
std::get<1> (m_storage).c_str (),
NULL, 1, noside);
if (x == NULL)
error (_("There is no field named %s"), std::get<1> (m_storage).c_str ());
return x;
}
value *
unop_ind_base_operation::evaluate_for_address (struct expression *exp,
enum noside noside)
{
value *x = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
/* We can't optimize out "&*" if there's a user-defined operator*. */
if (unop_user_defined_p (UNOP_IND, x))
{
x = value_x_unop (x, UNOP_IND, noside);
return evaluate_subexp_for_address_base (exp, noside, x);
}
return coerce_array (x);
}
value *
var_msym_value_operation::evaluate_for_address (struct expression *exp,
enum noside noside)
{
const bound_minimal_symbol &b = std::get<0> (m_storage);
value *val = evaluate_var_msym_value (noside, b.objfile, b.minsym);
if (noside == EVAL_AVOID_SIDE_EFFECTS)
{
struct type *type = lookup_pointer_type (value_type (val));
return value_zero (type, not_lval);
}
else
return value_addr (val);
}
value *
unop_memval_operation::evaluate_for_address (struct expression *exp,
enum noside noside)
{
return value_cast (lookup_pointer_type (std::get<1> (m_storage)),
std::get<0> (m_storage)->evaluate (nullptr, exp, noside));
}
value *
unop_memval_type_operation::evaluate_for_address (struct expression *exp,
enum noside noside)
{
value *typeval = std::get<0> (m_storage)->evaluate (nullptr, exp,
EVAL_AVOID_SIDE_EFFECTS);
struct type *type = value_type (typeval);
return value_cast (lookup_pointer_type (type),
std::get<1> (m_storage)->evaluate (nullptr, exp, noside));
}
value *
var_value_operation::evaluate_for_address (struct expression *exp,
enum noside noside)
{
symbol *var = std::get<0> (m_storage).symbol;
/* C++: The "address" of a reference should yield the address
* of the object pointed to. Let value_addr() deal with it. */
if (TYPE_IS_REFERENCE (var->type ()))
return operation::evaluate_for_address (exp, noside);
if (noside == EVAL_AVOID_SIDE_EFFECTS)
{
struct type *type = lookup_pointer_type (var->type ());
enum address_class sym_class = var->aclass ();
if (sym_class == LOC_CONST
|| sym_class == LOC_CONST_BYTES
|| sym_class == LOC_REGISTER)
error (_("Attempt to take address of register or constant."));
return value_zero (type, not_lval);
}
else
return address_of_variable (var, std::get<0> (m_storage).block);
}
value *
var_value_operation::evaluate_with_coercion (struct expression *exp,
enum noside noside)
{
struct symbol *var = std::get<0> (m_storage).symbol;
struct type *type = check_typedef (var->type ());
if (type->code () == TYPE_CODE_ARRAY
&& !type->is_vector ()
&& CAST_IS_CONVERSION (exp->language_defn))
{
struct value *val = address_of_variable (var,
std::get<0> (m_storage).block);
return value_cast (lookup_pointer_type (TYPE_TARGET_TYPE (type)), val);
}
return evaluate (nullptr, exp, noside);
}
}
/* Helper function for evaluating the size of a type. */
static value *
evaluate_subexp_for_sizeof_base (struct expression *exp, struct type *type)
{
/* FIXME: This should be size_t. */
struct type *size_type = builtin_type (exp->gdbarch)->builtin_int;
/* $5.3.3/2 of the C++ Standard (n3290 draft) says of sizeof:
"When applied to a reference or a reference type, the result is
the size of the referenced type." */
type = check_typedef (type);
if (exp->language_defn->la_language == language_cplus
&& (TYPE_IS_REFERENCE (type)))
type = check_typedef (TYPE_TARGET_TYPE (type));
return value_from_longest (size_type, (LONGEST) TYPE_LENGTH (type));
}
namespace expr
{
value *
operation::evaluate_for_sizeof (struct expression *exp, enum noside noside)
{
value *val = evaluate (nullptr, exp, EVAL_AVOID_SIDE_EFFECTS);
return evaluate_subexp_for_sizeof_base (exp, value_type (val));
}
value *
var_msym_value_operation::evaluate_for_sizeof (struct expression *exp,
enum noside noside)
{
const bound_minimal_symbol &b = std::get<0> (m_storage);
value *mval = evaluate_var_msym_value (noside, b.objfile, b.minsym);
struct type *type = value_type (mval);
if (type->code () == TYPE_CODE_ERROR)
error_unknown_type (b.minsym->print_name ());
/* FIXME: This should be size_t. */
struct type *size_type = builtin_type (exp->gdbarch)->builtin_int;
return value_from_longest (size_type, TYPE_LENGTH (type));
}
value *
subscript_operation::evaluate_for_sizeof (struct expression *exp,
enum noside noside)
{
if (noside == EVAL_NORMAL)
{
value *val = std::get<0> (m_storage)->evaluate (nullptr, exp,
EVAL_AVOID_SIDE_EFFECTS);
struct type *type = check_typedef (value_type (val));
if (type->code () == TYPE_CODE_ARRAY)
{
type = check_typedef (TYPE_TARGET_TYPE (type));
if (type->code () == TYPE_CODE_ARRAY)
{
type = type->index_type ();
/* Only re-evaluate the right hand side if the resulting type
is a variable length type. */
if (type->bounds ()->flag_bound_evaluated)
{
val = evaluate (nullptr, exp, EVAL_NORMAL);
/* FIXME: This should be size_t. */
struct type *size_type
= builtin_type (exp->gdbarch)->builtin_int;
return value_from_longest
(size_type, (LONGEST) TYPE_LENGTH (value_type (val)));
}
}
}
}
return operation::evaluate_for_sizeof (exp, noside);
}
value *
unop_ind_base_operation::evaluate_for_sizeof (struct expression *exp,
enum noside noside)
{
value *val = std::get<0> (m_storage)->evaluate (nullptr, exp,
EVAL_AVOID_SIDE_EFFECTS);
struct type *type = check_typedef (value_type (val));
if (!type->is_pointer_or_reference ()
&& type->code () != TYPE_CODE_ARRAY)
error (_("Attempt to take contents of a non-pointer value."));
type = TYPE_TARGET_TYPE (type);
if (is_dynamic_type (type))
type = value_type (value_ind (val));
/* FIXME: This should be size_t. */
struct type *size_type = builtin_type (exp->gdbarch)->builtin_int;
return value_from_longest (size_type, (LONGEST) TYPE_LENGTH (type));
}
value *
unop_memval_operation::evaluate_for_sizeof (struct expression *exp,
enum noside noside)
{
return evaluate_subexp_for_sizeof_base (exp, std::get<1> (m_storage));
}
value *
unop_memval_type_operation::evaluate_for_sizeof (struct expression *exp,
enum noside noside)
{
value *typeval = std::get<0> (m_storage)->evaluate (nullptr, exp,
EVAL_AVOID_SIDE_EFFECTS);
return evaluate_subexp_for_sizeof_base (exp, value_type (typeval));
}
value *
var_value_operation::evaluate_for_sizeof (struct expression *exp,
enum noside noside)
{
struct type *type = std::get<0> (m_storage).symbol->type ();
if (is_dynamic_type (type))
{
value *val = evaluate (nullptr, exp, EVAL_NORMAL);
type = value_type (val);
if (type->code () == TYPE_CODE_ARRAY)
{
/* FIXME: This should be size_t. */
struct type *size_type = builtin_type (exp->gdbarch)->builtin_int;
if (type_not_allocated (type) || type_not_associated (type))
return value_zero (size_type, not_lval);
else if (is_dynamic_type (type->index_type ())
&& type->bounds ()->high.kind () == PROP_UNDEFINED)
return allocate_optimized_out_value (size_type);
}
}
return evaluate_subexp_for_sizeof_base (exp, type);
}
value *
var_msym_value_operation::evaluate_for_cast (struct type *to_type,
struct expression *exp,
enum noside noside)
{
if (noside == EVAL_AVOID_SIDE_EFFECTS)
return value_zero (to_type, not_lval);
const bound_minimal_symbol &b = std::get<0> (m_storage);
value *val = evaluate_var_msym_value (noside, b.objfile, b.minsym);
val = value_cast (to_type, val);
/* Don't allow e.g. '&(int)var_with_no_debug_info'. */
if (VALUE_LVAL (val) == lval_memory)
{
if (value_lazy (val))
value_fetch_lazy (val);
VALUE_LVAL (val) = not_lval;
}
return val;
}
value *
var_value_operation::evaluate_for_cast (struct type *to_type,
struct expression *exp,
enum noside noside)
{
value *val = evaluate_var_value (noside,
std::get<0> (m_storage).block,
std::get<0> (m_storage).symbol);
val = value_cast (to_type, val);
/* Don't allow e.g. '&(int)var_with_no_debug_info'. */
if (VALUE_LVAL (val) == lval_memory)
{
if (value_lazy (val))
value_fetch_lazy (val);
VALUE_LVAL (val) = not_lval;
}
return val;
}
}
/* Parse a type expression in the string [P..P+LENGTH). */
struct type *
parse_and_eval_type (const char *p, int length)
{
char *tmp = (char *) alloca (length + 4);
tmp[0] = '(';
memcpy (tmp + 1, p, length);
tmp[length + 1] = ')';
tmp[length + 2] = '0';
tmp[length + 3] = '\0';
expression_up expr = parse_expression (tmp);
expr::unop_cast_operation *op
= dynamic_cast<expr::unop_cast_operation *> (expr->op.get ());
if (op == nullptr)
error (_("Internal error in eval_type."));
return op->get_type ();
}
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