aboutsummaryrefslogtreecommitdiff
path: root/gdb/eval.c
diff options
context:
space:
mode:
Diffstat (limited to 'gdb/eval.c')
-rw-r--r--gdb/eval.c1042
1 files changed, 1042 insertions, 0 deletions
diff --git a/gdb/eval.c b/gdb/eval.c
new file mode 100644
index 0000000..0cf5cbf
--- /dev/null
+++ b/gdb/eval.c
@@ -0,0 +1,1042 @@
+/* Evaluate expressions for GDB.
+ Copyright (C) 1986, 1987, 1989 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+GDB 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 1, or (at your option)
+any later version.
+
+GDB 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 GDB; see the file COPYING. If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "defs.h"
+#include "param.h"
+#include "symtab.h"
+#include "value.h"
+#include "expression.h"
+#include "target.h"
+
+#define NULL_TYPE ((struct type *)0)
+
+
+/* Parse the string EXP as a C expression, evaluate it,
+ and return the result as a number. */
+
+CORE_ADDR
+parse_and_eval_address (exp)
+ char *exp;
+{
+ struct expression *expr = parse_c_expression (exp);
+ register CORE_ADDR addr;
+ register struct cleanup *old_chain
+ = make_cleanup (free_current_contents, &expr);
+
+ addr = (CORE_ADDR) value_as_long (evaluate_expression (expr));
+ do_cleanups (old_chain);
+ return addr;
+}
+
+/* Like parse_and_eval_address but takes a pointer to a char * variable
+ and advanced that variable across the characters parsed. */
+
+CORE_ADDR
+parse_and_eval_address_1 (expptr)
+ char **expptr;
+{
+ struct expression *expr = parse_c_1 (expptr, 0, 0);
+ register CORE_ADDR addr;
+ register struct cleanup *old_chain
+ = make_cleanup (free_current_contents, &expr);
+
+ addr = (CORE_ADDR) value_as_long (evaluate_expression (expr));
+ do_cleanups (old_chain);
+ return addr;
+}
+
+value
+parse_and_eval (exp)
+ char *exp;
+{
+ struct expression *expr = parse_c_expression (exp);
+ register value val;
+ register struct cleanup *old_chain
+ = make_cleanup (free_current_contents, &expr);
+
+ val = evaluate_expression (expr);
+ do_cleanups (old_chain);
+ return val;
+}
+
+/* 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. */
+
+value
+parse_to_comma_and_eval (expp)
+ char **expp;
+{
+ struct expression *expr = parse_c_1 (expp, 0, 1);
+ register value val;
+ register struct cleanup *old_chain
+ = make_cleanup (free_current_contents, &expr);
+
+ val = evaluate_expression (expr);
+ do_cleanups (old_chain);
+ return val;
+}
+
+/* Evaluate an expression in internal prefix form
+ such as is constructed by expread.y.
+
+ See expression.h for info on the format of an expression. */
+
+static value evaluate_subexp ();
+static value evaluate_subexp_for_address ();
+static value evaluate_subexp_for_sizeof ();
+static value evaluate_subexp_with_coercion ();
+
+/* Values of NOSIDE argument to eval_subexp. */
+enum noside
+{ EVAL_NORMAL,
+ EVAL_SKIP, /* Only effect is to increment pos. */
+ EVAL_AVOID_SIDE_EFFECTS, /* Don't modify any variables or
+ call any functions. The value
+ returned will have the correct
+ type, and will have an
+ approximately correct lvalue
+ type (inaccuracy: anything that is
+ listed as being in a register in
+ the function in which it was
+ declared will be lval_register). */
+};
+
+value
+evaluate_expression (exp)
+ struct expression *exp;
+{
+ int pc = 0;
+ return evaluate_subexp (NULL_TYPE, exp, &pc, EVAL_NORMAL);
+}
+
+/* Evaluate an expression, avoiding all memory references
+ and getting a value whose type alone is correct. */
+
+value
+evaluate_type (exp)
+ struct expression *exp;
+{
+ int pc = 0;
+ return evaluate_subexp (NULL_TYPE, exp, &pc, EVAL_AVOID_SIDE_EFFECTS);
+}
+
+static value
+evaluate_subexp (expect_type, exp, pos, noside)
+ struct type *expect_type;
+ register struct expression *exp;
+ register int *pos;
+ enum noside noside;
+{
+ enum exp_opcode op;
+ int tem;
+ register int pc, pc2, oldpos;
+ register value arg1, arg2, arg3;
+ int nargs;
+ value *argvec;
+
+ pc = (*pos)++;
+ op = exp->elts[pc].opcode;
+
+ switch (op)
+ {
+ case OP_SCOPE:
+ tem = strlen (&exp->elts[pc + 2].string);
+ (*pos) += 3 + ((tem + sizeof (union exp_element))
+ / sizeof (union exp_element));
+ return value_static_field (exp->elts[pc + 1].type,
+ &exp->elts[pc + 2].string, -1);
+
+ case OP_LONG:
+ (*pos) += 3;
+ return value_from_long (exp->elts[pc + 1].type,
+ exp->elts[pc + 2].longconst);
+
+ case OP_DOUBLE:
+ (*pos) += 3;
+ return value_from_double (exp->elts[pc + 1].type,
+ exp->elts[pc + 2].doubleconst);
+
+ case OP_VAR_VALUE:
+ (*pos) += 2;
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ {
+ struct symbol * sym = exp->elts[pc + 1].symbol;
+ enum lval_type lv;
+
+ switch (SYMBOL_CLASS (sym))
+ {
+ case LOC_CONST:
+ case LOC_LABEL:
+ case LOC_CONST_BYTES:
+ lv = not_lval;
+ break;
+
+ case LOC_REGISTER:
+ case LOC_REGPARM:
+ lv = lval_register;
+ break;
+
+ default:
+ lv = lval_memory;
+ break;
+ }
+
+ return value_zero (SYMBOL_TYPE (sym), lv);
+ }
+ else
+ return value_of_variable (exp->elts[pc + 1].symbol);
+
+ case OP_LAST:
+ (*pos) += 2;
+ return access_value_history ((int) exp->elts[pc + 1].longconst);
+
+ case OP_REGISTER:
+ (*pos) += 2;
+ return value_of_register ((int) exp->elts[pc + 1].longconst);
+
+ case OP_INTERNALVAR:
+ (*pos) += 2;
+ return value_of_internalvar (exp->elts[pc + 1].internalvar);
+
+ case OP_STRING:
+ tem = strlen (&exp->elts[pc + 1].string);
+ (*pos) += 2 + ((tem + sizeof (union exp_element))
+ / sizeof (union exp_element));
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ return value_string (&exp->elts[pc + 1].string, tem);
+
+ case TERNOP_COND:
+ /* Skip third and second args to evaluate the first one. */
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (value_zerop (arg1))
+ {
+ evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP);
+ return evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ }
+ else
+ {
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP);
+ return arg2;
+ }
+
+ case OP_FUNCALL:
+ (*pos) += 2;
+ op = exp->elts[*pos].opcode;
+ if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR)
+ {
+ int fnptr;
+
+ nargs = (int) exp->elts[pc + 1].longconst + 1;
+ /* First, evaluate the structure into arg2 */
+ pc2 = (*pos)++;
+
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+
+ if (op == STRUCTOP_MEMBER)
+ {
+ arg2 = evaluate_subexp_for_address (exp, pos, noside);
+ }
+ else
+ {
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ }
+
+ /* 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. */
+
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+
+ fnptr = (int) value_as_long (arg1);
+ if (fnptr < 128)
+ {
+ struct type *basetype;
+ int i, j;
+ basetype = TYPE_TARGET_TYPE (VALUE_TYPE (arg2));
+ basetype = TYPE_VPTR_BASETYPE (basetype);
+ for (i = TYPE_NFN_FIELDS (basetype) - 1; i >= 0; i--)
+ {
+ struct fn_field *f = TYPE_FN_FIELDLIST1 (basetype, i);
+ /* If one is virtual, then all are virtual. */
+ if (TYPE_FN_FIELD_VIRTUAL_P (f, 0))
+ for (j = TYPE_FN_FIELDLIST_LENGTH (basetype, i) - 1; j >= 0; --j)
+ if (TYPE_FN_FIELD_VOFFSET (f, j) == fnptr)
+ {
+ value vtbl;
+ value base = value_ind (arg2);
+ struct type *fntype = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j));
+
+ if (TYPE_VPTR_FIELDNO (basetype) < 0)
+ TYPE_VPTR_FIELDNO (basetype)
+ = fill_in_vptr_fieldno (basetype);
+
+ VALUE_TYPE (base) = basetype;
+ vtbl = value_field (base, TYPE_VPTR_FIELDNO (basetype));
+ VALUE_TYPE (vtbl) = lookup_pointer_type (fntype);
+ VALUE_TYPE (arg1) = builtin_type_int;
+ arg1 = value_subscript (vtbl, arg1);
+ VALUE_TYPE (arg1) = fntype;
+ goto got_it;
+ }
+ }
+ if (i < 0)
+ error ("virtual function at index %d not found", fnptr);
+ }
+ else
+ {
+ VALUE_TYPE (arg1) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)));
+ }
+ got_it:
+
+ /* Now, say which argument to start evaluating from */
+ tem = 2;
+ }
+ else if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR)
+ {
+ /* Hair for method invocations */
+ int tem2;
+
+ nargs = (int) exp->elts[pc + 1].longconst + 1;
+ /* First, evaluate the structure into arg2 */
+ pc2 = (*pos)++;
+ tem2 = strlen (&exp->elts[pc2 + 1].string);
+ *pos += 2 + (tem2 + sizeof (union exp_element)) / sizeof (union exp_element);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+
+ if (op == STRUCTOP_STRUCT)
+ {
+ arg2 = evaluate_subexp_for_address (exp, pos, noside);
+ }
+ else
+ {
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ }
+ /* Now, say which argument to start evaluating from */
+ tem = 2;
+ }
+ else
+ {
+ nargs = (int) exp->elts[pc + 1].longconst;
+ tem = 0;
+ }
+ argvec = (value *) alloca (sizeof (value) * (nargs + 2));
+ for (; tem <= nargs; tem++)
+ /* Ensure that array expressions are coerced into pointer objects. */
+ argvec[tem] = evaluate_subexp_with_coercion (exp, pos, noside);
+
+ /* signal end of arglist */
+ argvec[tem] = 0;
+
+ if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR)
+ {
+ int static_memfuncp;
+ value temp = arg2;
+
+ argvec[1] = arg2;
+ argvec[0] =
+ value_struct_elt (&temp, argvec+1, &exp->elts[pc2 + 1].string,
+ &static_memfuncp,
+ op == STRUCTOP_STRUCT
+ ? "structure" : "structure pointer");
+ if (VALUE_OFFSET (temp))
+ {
+ arg2 = value_from_long (builtin_type_long,
+ value_as_long (arg2)+VALUE_OFFSET (temp));
+ VALUE_TYPE (arg2) = lookup_pointer_type (VALUE_TYPE (temp));
+ argvec[1] = arg2;
+ }
+ if (static_memfuncp)
+ {
+ argvec[1] = argvec[0];
+ nargs--;
+ argvec++;
+ }
+ }
+ else if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR)
+ {
+ argvec[1] = arg2;
+ argvec[0] = arg1;
+ }
+
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ 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 *ftype =
+ TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0]));
+
+ if (ftype)
+ return allocate_value (TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0])));
+ else
+ error ("Expression of type other than \"Function returning ...\" used as function");
+ }
+ return target_call_function (argvec[0], nargs, argvec + 1);
+
+ case STRUCTOP_STRUCT:
+ tem = strlen (&exp->elts[pc + 1].string);
+ (*pos) += 2 + ((tem + sizeof (union exp_element))
+ / sizeof (union exp_element));
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ return value_zero (lookup_struct_elt_type (VALUE_TYPE (arg1),
+ &exp->elts[pc + 1].string),
+ lval_memory);
+ else
+ {
+ value temp = arg1;
+ return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 1].string,
+ (int *) 0, "structure");
+ }
+
+ case STRUCTOP_PTR:
+ tem = strlen (&exp->elts[pc + 1].string);
+ (*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element);
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ return value_zero (lookup_struct_elt_type (TYPE_TARGET_TYPE
+ (VALUE_TYPE (arg1)),
+ &exp->elts[pc + 1].string),
+ lval_memory);
+ else
+ {
+ value temp = arg1;
+ return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 1].string,
+ (int *) 0, "structure pointer");
+ }
+
+ case STRUCTOP_MEMBER:
+ arg1 = evaluate_subexp_for_address (exp, pos, noside);
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ /* Now, convert these values to an address. */
+ if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_PTR
+ || ((TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2)))
+ != TYPE_CODE_MEMBER)
+ && (TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2)))
+ != TYPE_CODE_METHOD)))
+ error ("non-pointer-to-member value used in pointer-to-member construct");
+ arg3 = value_from_long (builtin_type_long,
+ value_as_long (arg1) + value_as_long (arg2));
+ VALUE_TYPE (arg3) =
+ lookup_pointer_type (TYPE_TARGET_TYPE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))));
+ return value_ind (arg3);
+
+ case STRUCTOP_MPTR:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ /* Now, convert these values to an address. */
+ if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_PTR
+ || (TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))) != TYPE_CODE_MEMBER
+ && TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))) != TYPE_CODE_METHOD))
+ error ("non-pointer-to-member value used in pointer-to-member construct");
+ arg3 = value_from_long (builtin_type_long,
+ value_as_long (arg1) + value_as_long (arg2));
+ VALUE_TYPE (arg3) =
+ lookup_pointer_type (TYPE_TARGET_TYPE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))));
+ return value_ind (arg3);
+
+ case BINOP_ASSIGN:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
+ return arg1;
+ if (binop_user_defined_p (op, arg1, arg2))
+ return value_x_binop (arg1, arg2, op, 0);
+ else
+ return value_assign (arg1, arg2);
+
+ case BINOP_ASSIGN_MODIFY:
+ (*pos) += 2;
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
+ return arg1;
+ op = exp->elts[pc + 1].opcode;
+ if (binop_user_defined_p (op, arg1, arg2))
+ return value_x_binop (arg1, arg2, BINOP_ASSIGN_MODIFY, op);
+ else if (op == BINOP_ADD)
+ arg2 = value_add (arg1, arg2);
+ else if (op == BINOP_SUB)
+ arg2 = value_sub (arg1, arg2);
+ else
+ arg2 = value_binop (arg1, arg2, op);
+ return value_assign (arg1, arg2);
+
+ case BINOP_ADD:
+ arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
+ arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ return value_x_binop (arg1, arg2, op, 0);
+ else
+ return value_add (arg1, arg2);
+
+ case BINOP_SUB:
+ arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
+ arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ return value_x_binop (arg1, arg2, op, 0);
+ else
+ return value_sub (arg1, arg2);
+
+ case BINOP_MUL:
+ case BINOP_DIV:
+ case BINOP_REM:
+ case BINOP_LSH:
+ case BINOP_RSH:
+ case BINOP_LOGAND:
+ case BINOP_LOGIOR:
+ case BINOP_LOGXOR:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ return value_x_binop (arg1, arg2, op, 0);
+ else
+ if (noside == EVAL_AVOID_SIDE_EFFECTS
+ && op == BINOP_DIV)
+ return value_zero (VALUE_TYPE (arg1), not_lval);
+ else
+ return value_binop (arg1, arg2, op);
+
+ case BINOP_SUBSCRIPT:
+ arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
+ arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)),
+ VALUE_LVAL (arg1));
+
+ if (binop_user_defined_p (op, arg1, arg2))
+ return value_x_binop (arg1, arg2, op, 0);
+ else
+ return value_subscript (arg1, arg2);
+
+ case BINOP_AND:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ {
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ goto nosideret;
+ }
+
+ oldpos = *pos;
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
+ *pos = oldpos;
+
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_zerop (arg1);
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos,
+ (tem ? EVAL_SKIP : noside));
+ return value_from_long (builtin_type_int,
+ (LONGEST) (!tem && !value_zerop (arg2)));
+ }
+
+ case BINOP_OR:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ {
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ goto nosideret;
+ }
+
+ oldpos = *pos;
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
+ *pos = oldpos;
+
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_zerop (arg1);
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos,
+ (!tem ? EVAL_SKIP : noside));
+ return value_from_long (builtin_type_int,
+ (LONGEST) (!tem || !value_zerop (arg2)));
+ }
+
+ case BINOP_EQUAL:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_equal (arg1, arg2);
+ return value_from_long (builtin_type_int, (LONGEST) tem);
+ }
+
+ case BINOP_NOTEQUAL:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_equal (arg1, arg2);
+ return value_from_long (builtin_type_int, (LONGEST) ! tem);
+ }
+
+ case BINOP_LESS:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_less (arg1, arg2);
+ return value_from_long (builtin_type_int, (LONGEST) tem);
+ }
+
+ case BINOP_GTR:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_less (arg2, arg1);
+ return value_from_long (builtin_type_int, (LONGEST) tem);
+ }
+
+ case BINOP_GEQ:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_less (arg1, arg2);
+ return value_from_long (builtin_type_int, (LONGEST) ! tem);
+ }
+
+ case BINOP_LEQ:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (binop_user_defined_p (op, arg1, arg2))
+ {
+ return value_x_binop (arg1, arg2, op, 0);
+ }
+ else
+ {
+ tem = value_less (arg2, arg1);
+ return value_from_long (builtin_type_int, (LONGEST) ! tem);
+ }
+
+ case BINOP_REPEAT:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_INT)
+ error ("Non-integral right operand for \"@\" operator.");
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ return allocate_repeat_value (VALUE_TYPE (arg1),
+ (int) value_as_long (arg2));
+ else
+ return value_repeat (arg1, (int) value_as_long (arg2));
+
+ case BINOP_COMMA:
+ evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ return evaluate_subexp (NULL_TYPE, exp, pos, noside);
+
+ case UNOP_NEG:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (unop_user_defined_p (op, arg1))
+ return value_x_unop (arg1, op);
+ else
+ return value_neg (arg1);
+
+ case UNOP_LOGNOT:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (unop_user_defined_p (op, arg1))
+ return value_x_unop (arg1, op);
+ else
+ return value_lognot (arg1);
+
+ case UNOP_ZEROP:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (unop_user_defined_p (op, arg1))
+ return value_x_unop (arg1, op);
+ else
+ return value_from_long (builtin_type_int,
+ (LONGEST) value_zerop (arg1));
+
+ case UNOP_IND:
+ if (expect_type && TYPE_CODE (expect_type) == TYPE_CODE_PTR)
+ expect_type = TYPE_TARGET_TYPE (expect_type);
+ arg1 = evaluate_subexp (expect_type, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ {
+ if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR
+ || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_REF
+ /* In C you can dereference an array to get the 1st elt. */
+ || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_ARRAY
+ )
+ return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)),
+ lval_memory);
+ else if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_INT)
+ /* GDB allows dereferencing an int. */
+ return value_zero (builtin_type_int, lval_memory);
+ else
+ error ("Attempt to take contents of a non-pointer value.");
+ }
+ return value_ind (arg1);
+
+ case UNOP_ADDR:
+ /* C++: check for and handle pointer to members. */
+
+ op = exp->elts[*pos].opcode;
+
+ if (noside == EVAL_SKIP)
+ {
+ if (op == OP_SCOPE)
+ {
+ char *name = &exp->elts[pc+3].string;
+ int temm = strlen (name);
+ (*pos) += 2 + (temm + sizeof (union exp_element)) / sizeof (union exp_element);
+ }
+ else
+ evaluate_subexp (expect_type, exp, pos, EVAL_SKIP);
+ goto nosideret;
+ }
+
+ if (op == OP_SCOPE)
+ {
+ char *name = &exp->elts[pc+3].string;
+ int temm = strlen (name);
+ struct type *domain = exp->elts[pc+2].type;
+ (*pos) += 2 + (temm + sizeof (union exp_element)) / sizeof (union exp_element);
+ arg1 = value_struct_elt_for_address (domain, expect_type, name);
+ if (arg1)
+ return arg1;
+ error ("no field `%s' in structure", name);
+ }
+ else
+ return evaluate_subexp_for_address (exp, pos, noside);
+
+ case UNOP_SIZEOF:
+ if (noside == EVAL_SKIP)
+ {
+ evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP);
+ goto nosideret;
+ }
+ return evaluate_subexp_for_sizeof (exp, pos);
+
+ case UNOP_CAST:
+ (*pos) += 2;
+ arg1 = evaluate_subexp (expect_type, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ return value_cast (exp->elts[pc + 1].type, arg1);
+
+ case UNOP_MEMVAL:
+ (*pos) += 2;
+ arg1 = evaluate_subexp (expect_type, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ goto nosideret;
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ return value_zero (exp->elts[pc + 1].type, lval_memory);
+ else
+ return value_at_lazy (exp->elts[pc + 1].type,
+ (CORE_ADDR) value_as_long (arg1));
+
+ case UNOP_PREINCREMENT:
+ arg1 = evaluate_subexp (expect_type, exp, pos, noside);
+ if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
+ return arg1;
+ else if (unop_user_defined_p (op, arg1))
+ {
+ return value_x_unop (arg1, op);
+ }
+ else
+ {
+ arg2 = value_add (arg1, value_from_long (builtin_type_char,
+ (LONGEST) 1));
+ return value_assign (arg1, arg2);
+ }
+
+ case UNOP_PREDECREMENT:
+ arg1 = evaluate_subexp (expect_type, exp, pos, noside);
+ if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
+ return arg1;
+ else if (unop_user_defined_p (op, arg1))
+ {
+ return value_x_unop (arg1, op);
+ }
+ else
+ {
+ arg2 = value_sub (arg1, value_from_long (builtin_type_char,
+ (LONGEST) 1));
+ return value_assign (arg1, arg2);
+ }
+
+ case UNOP_POSTINCREMENT:
+ arg1 = evaluate_subexp (expect_type, exp, pos, noside);
+ if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
+ return arg1;
+ else if (unop_user_defined_p (op, arg1))
+ {
+ return value_x_unop (arg1, op);
+ }
+ else
+ {
+ arg2 = value_add (arg1, value_from_long (builtin_type_char,
+ (LONGEST) 1));
+ value_assign (arg1, arg2);
+ return arg1;
+ }
+
+ case UNOP_POSTDECREMENT:
+ arg1 = evaluate_subexp (expect_type, exp, pos, noside);
+ if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
+ return arg1;
+ else if (unop_user_defined_p (op, arg1))
+ {
+ return value_x_unop (arg1, op);
+ }
+ else
+ {
+ arg2 = value_sub (arg1, value_from_long (builtin_type_char,
+ (LONGEST) 1));
+ value_assign (arg1, arg2);
+ return arg1;
+ }
+
+ case OP_THIS:
+ (*pos) += 1;
+ return value_of_this (1);
+
+ default:
+ error ("internal error: I do not know how to evaluate what you gave me");
+ }
+
+ nosideret:
+ return value_from_long (builtin_type_long, (LONGEST) 1);
+}
+
+/* Evaluate a subexpression of EXP, at index *POS,
+ and return the address of that subexpression.
+ Advance *POS over the subexpression.
+ If the subexpression isn't an lvalue, get an error.
+ NOSIDE may be EVAL_AVOID_SIDE_EFFECTS;
+ then only the type of the result need be correct. */
+
+static value
+evaluate_subexp_for_address (exp, pos, noside)
+ register struct expression *exp;
+ register int *pos;
+ enum noside noside;
+{
+ enum exp_opcode op;
+ register int pc;
+
+ pc = (*pos);
+ op = exp->elts[pc].opcode;
+
+ switch (op)
+ {
+ case UNOP_IND:
+ (*pos)++;
+ return evaluate_subexp (NULL_TYPE, exp, pos, noside);
+
+ case UNOP_MEMVAL:
+ (*pos) += 3;
+ return value_cast (lookup_pointer_type (exp->elts[pc + 1].type),
+ evaluate_subexp (NULL_TYPE, exp, pos, noside));
+
+ case OP_VAR_VALUE:
+ (*pos) += 3;
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ {
+ struct type *type =
+ lookup_pointer_type (SYMBOL_TYPE (exp->elts[pc + 1].symbol));
+ enum address_class sym_class =
+ SYMBOL_CLASS (exp->elts[pc + 1].symbol);
+
+ if (sym_class == LOC_CONST
+ || sym_class == LOC_CONST_BYTES
+ || sym_class == LOC_REGISTER
+ || sym_class == LOC_REGPARM)
+ error ("Attempt to take address of register or constant.");
+
+ return
+ value_zero (type, not_lval);
+ }
+ else
+ return locate_var_value (exp->elts[pc + 1].symbol, (CORE_ADDR) 0);
+
+ default:
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ {
+ value x = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (VALUE_LVAL (x) == lval_memory)
+ return value_zero (TYPE_POINTER_TYPE (VALUE_TYPE (x)),
+ not_lval);
+ else
+ error ("Attempt to take address of non-lval");
+ }
+ return value_addr (evaluate_subexp (NULL_TYPE, exp, pos, noside));
+ }
+}
+
+/* Evaluate like `evaluate_subexp' except coercing arrays to pointers.
+ When used in contexts where arrays will be coerced anyway,
+ this is equivalent to `evaluate_subexp'
+ but much faster because it avoids actually fetching array contents. */
+
+static value
+evaluate_subexp_with_coercion (exp, pos, noside)
+ register struct expression *exp;
+ register int *pos;
+ enum noside noside;
+{
+ register enum exp_opcode op;
+ register int pc;
+ register value val;
+
+ pc = (*pos);
+ op = exp->elts[pc].opcode;
+
+ switch (op)
+ {
+ case OP_VAR_VALUE:
+ if (TYPE_CODE (SYMBOL_TYPE (exp->elts[pc + 1].symbol)) == TYPE_CODE_ARRAY)
+ {
+ (*pos) += 3;
+ val = locate_var_value (exp->elts[pc + 1].symbol, (CORE_ADDR) 0);
+ return value_cast (lookup_pointer_type (TYPE_TARGET_TYPE (SYMBOL_TYPE (exp->elts[pc + 1].symbol))),
+ val);
+ }
+ default:
+ return evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ }
+}
+
+/* Evaluate a subexpression of EXP, at index *POS,
+ and return a value for the size of that subexpression.
+ Advance *POS over the subexpression. */
+
+static value
+evaluate_subexp_for_sizeof (exp, pos)
+ register struct expression *exp;
+ register int *pos;
+{
+ enum exp_opcode op;
+ register int pc;
+ value val;
+
+ pc = (*pos);
+ op = exp->elts[pc].opcode;
+
+ switch (op)
+ {
+ /* This case is handled specially
+ so that we avoid creating a value for the result type.
+ If the result type is very big, it's desirable not to
+ create a value unnecessarily. */
+ case UNOP_IND:
+ (*pos)++;
+ val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
+ return value_from_long (builtin_type_int, (LONGEST)
+ TYPE_LENGTH (TYPE_TARGET_TYPE (VALUE_TYPE (val))));
+
+ case UNOP_MEMVAL:
+ (*pos) += 3;
+ return value_from_long (builtin_type_int,
+ (LONGEST) TYPE_LENGTH (exp->elts[pc + 1].type));
+
+ case OP_VAR_VALUE:
+ (*pos) += 3;
+ return value_from_long (builtin_type_int,
+ (LONGEST) TYPE_LENGTH (SYMBOL_TYPE (exp->elts[pc + 1].symbol)));
+
+ default:
+ val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
+ return value_from_long (builtin_type_int,
+ (LONGEST) TYPE_LENGTH (VALUE_TYPE (val)));
+ }
+}