diff options
Diffstat (limited to 'gdb/eval.c')
| -rw-r--r-- | gdb/eval.c | 1042 |
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))); + } +} |