305 lines
9.3 KiB
C
305 lines
9.3 KiB
C
/* Print in infix form a struct expression.
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Copyright (C) 1986 Free Software Foundation, Inc.
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GDB is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY. No author or distributor accepts responsibility to anyone
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for the consequences of using it or for whether it serves any
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particular purpose or works at all, unless he says so in writing.
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Refer to the GDB General Public License for full details.
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Everyone is granted permission to copy, modify and redistribute GDB,
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but only under the conditions described in the GDB General Public
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License. A copy of this license is supposed to have been given to you
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along with GDB so you can know your rights and responsibilities. It
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should be in a file named COPYING. Among other things, the copyright
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notice and this notice must be preserved on all copies.
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In other words, go ahead and share GDB, but don't try to stop
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anyone else from sharing it farther. Help stamp out software hoarding!
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*/
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#include "defs.h"
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#include "symtab.h"
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#include "expression.h"
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#include <stdio.h>
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/* These codes indicate operator precedences, least tightly binding first. */
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/* Adding 1 to a precedence value is done for binary operators,
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on the operand which is more tightly bound, so that operators
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of equal precedence within that operand will get parentheses. */
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/* PREC_HYPER and PREC_ABOVE_COMMA are not the precedence of any operator;
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they are used as the "surrounding precedence" to force
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various kinds of things to be parenthesized. */
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enum precedence
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{ PREC_NULL, PREC_COMMA, PREC_ABOVE_COMMA, PREC_ASSIGN, PREC_OR, PREC_AND,
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PREC_LOGIOR, PREC_LOGAND, PREC_LOGXOR, PREC_EQUAL, PREC_ORDER,
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PREC_SHIFT, PREC_ADD, PREC_MUL, PREC_REPEAT,
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PREC_HYPER, PREC_PREFIX, PREC_SUFFIX };
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/* Table mapping opcodes into strings for printing operators
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and precedences of the operators. */
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struct op_print
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{
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char *string;
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enum exp_opcode opcode;
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/* Precedence of operator. These values are used only by comparisons. */
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enum precedence precedence;
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int right_assoc;
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};
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static struct op_print op_print_tab[] =
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{
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{",", BINOP_COMMA, PREC_COMMA, 0},
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{"=", BINOP_ASSIGN, PREC_ASSIGN, 1},
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{"||", BINOP_OR, PREC_OR, 0},
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{"&&", BINOP_AND, PREC_AND, 0},
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{"|", BINOP_LOGIOR, PREC_LOGIOR, 0},
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{"&", BINOP_LOGAND, PREC_LOGAND, 0},
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{"^", BINOP_LOGXOR, PREC_LOGXOR, 0},
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{"==", BINOP_EQUAL, PREC_EQUAL, 0},
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{"!=", BINOP_NOTEQUAL, PREC_EQUAL, 0},
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{"<=", BINOP_LEQ, PREC_ORDER, 0},
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{">=", BINOP_GEQ, PREC_ORDER, 0},
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{">", BINOP_GTR, PREC_ORDER, 0},
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{"<", BINOP_LESS, PREC_ORDER, 0},
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{">>", BINOP_RSH, PREC_SHIFT, 0},
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{"<<", BINOP_LSH, PREC_SHIFT, 0},
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{"+", BINOP_ADD, PREC_ADD, 0},
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{"-", BINOP_SUB, PREC_ADD, 0},
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{"*", BINOP_MUL, PREC_MUL, 0},
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{"/", BINOP_DIV, PREC_MUL, 0},
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{"%", BINOP_REM, PREC_MUL, 0},
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{"@", BINOP_REPEAT, PREC_REPEAT, 0},
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{"-", UNOP_NEG, PREC_PREFIX, 0},
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{"!", UNOP_ZEROP, PREC_PREFIX, 0},
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{"~", UNOP_LOGNOT, PREC_PREFIX, 0},
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{"*", UNOP_IND, PREC_PREFIX, 0},
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{"&", UNOP_ADDR, PREC_PREFIX, 0},
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{"sizeof ", UNOP_SIZEOF, PREC_PREFIX, 0},
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{"++", UNOP_PREINCREMENT, PREC_PREFIX, 0},
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{"--", UNOP_PREDECREMENT, PREC_PREFIX, 0}
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};
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static void print_subexp ();
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void
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print_expression (exp, stream)
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struct expression *exp;
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FILE *stream;
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{
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int pc = 0;
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print_subexp (exp, &pc, stream, PREC_NULL);
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}
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/* Print the subexpression of EXP that starts in position POS, on STREAM.
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PREC is the precedence of the surrounding operator;
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if the precedence of the main operator of this subexpression is less,
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parentheses are needed here. */
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static void
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print_subexp (exp, pos, stream, prec)
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register struct expression *exp;
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register int *pos;
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FILE *stream;
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enum precedence prec;
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{
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register int tem;
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register int pc;
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int nargs;
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register char *op_str;
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int assign_modify = 0;
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enum exp_opcode opcode;
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enum precedence myprec;
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/* Set to 1 for a right-associative operator. */
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int assoc;
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pc = (*pos)++;
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opcode = exp->elts[pc].opcode;
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switch (opcode)
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{
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case OP_LONG:
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(*pos) += 3;
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value_print (value_from_long (exp->elts[pc + 1].type,
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exp->elts[pc + 2].longconst),
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stream, 0);
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return;
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case OP_DOUBLE:
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(*pos) += 3;
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value_print (value_from_double (exp->elts[pc + 1].type,
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exp->elts[pc + 2].doubleconst),
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stream, 0);
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return;
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case OP_VAR_VALUE:
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(*pos) += 2;
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fprintf (stream, "%s", SYMBOL_NAME (exp->elts[pc + 1].symbol));
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return;
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case OP_LAST:
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(*pos) += 2;
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fprintf (stream, "$%d", exp->elts[pc + 1].longconst);
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return;
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case OP_REGISTER:
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(*pos) += 2;
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fprintf (stream, "$%s", reg_names[exp->elts[pc + 1].longconst]);
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return;
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case OP_INTERNALVAR:
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(*pos) += 2;
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fprintf (stream, "$%s",
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internalvar_name (exp->elts[pc + 1].internalvar));
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return;
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case OP_FUNCALL:
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(*pos) += 2;
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nargs = exp->elts[pc + 1].longconst;
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print_subexp (exp, pos, stream, PREC_SUFFIX);
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fprintf (stream, " (");
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for (tem = 0; tem < nargs; tem++)
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{
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if (tem > 0)
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fprintf (stream, ", ");
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print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
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}
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fprintf (stream, ")");
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return;
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case OP_STRING:
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nargs = strlen (&exp->elts[pc + 1].string);
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(*pos) += 2 + (nargs + sizeof (union exp_element)) / sizeof (union exp_element);
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fprintf (stream, "\"");
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for (tem = 0; tem < nargs; tem++)
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printchar ((&exp->elts[pc + 1].string)[tem], stream, '"');
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fprintf (stream, "\"");
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return;
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case TERNOP_COND:
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if ((int) prec > (int) PREC_COMMA)
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fprintf (stream, "(");
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/* Print the subexpressions, forcing parentheses
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around any binary operations within them.
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This is more parentheses than are strictly necessary,
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but it looks clearer. */
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print_subexp (exp, pos, stream, PREC_HYPER);
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fprintf (stream, " ? ");
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print_subexp (exp, pos, stream, PREC_HYPER);
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fprintf (stream, " : ");
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print_subexp (exp, pos, stream, PREC_HYPER);
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if ((int) prec > (int) PREC_COMMA)
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fprintf (stream, ")");
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return;
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case STRUCTOP_STRUCT:
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tem = strlen (&exp->elts[pc + 1].string);
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(*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element);
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print_subexp (exp, pos, stream, PREC_SUFFIX);
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fprintf (stream, ".%s", &exp->elts[pc + 1].string);
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return;
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case STRUCTOP_PTR:
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tem = strlen (&exp->elts[pc + 1].string);
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(*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element);
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print_subexp (exp, pos, stream, PREC_SUFFIX);
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fprintf (stream, "->%s", &exp->elts[pc + 1].string);
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return;
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case BINOP_SUBSCRIPT:
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print_subexp (exp, pos, stream, PREC_SUFFIX);
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fprintf (stream, "[");
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print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
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fprintf (stream, "]");
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return;
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case UNOP_POSTINCREMENT:
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print_subexp (exp, pos, stream, PREC_SUFFIX);
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fprintf (stream, "++");
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return;
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case UNOP_POSTDECREMENT:
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print_subexp (exp, pos, stream, PREC_SUFFIX);
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fprintf (stream, "--");
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return;
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case UNOP_CAST:
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(*pos) += 2;
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if ((int) prec > (int) PREC_PREFIX)
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fprintf (stream, "(");
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fprintf (stream, "(");
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type_print (exp->elts[pc + 1].type, "", stream, 0);
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fprintf (stream, ") ");
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print_subexp (exp, pos, stream, PREC_PREFIX);
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if ((int) prec > (int) PREC_PREFIX)
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fprintf (stream, ")");
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return;
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case UNOP_MEMVAL:
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(*pos) += 2;
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if ((int) prec > (int) PREC_PREFIX)
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fprintf (stream, "(");
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fprintf (stream, "{");
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type_print (exp->elts[pc + 1].type, "", stream, 0);
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fprintf (stream, "} ");
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print_subexp (exp, pos, stream, PREC_PREFIX);
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if ((int) prec > (int) PREC_PREFIX)
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fprintf (stream, ")");
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return;
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case BINOP_ASSIGN_MODIFY:
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opcode = exp->elts[pc + 1].opcode;
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(*pos) += 2;
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myprec = PREC_ASSIGN;
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assoc = 1;
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assign_modify = 1;
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for (tem = 0; tem < sizeof op_print_tab / sizeof op_print_tab[0]; tem++)
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if (op_print_tab[tem].opcode == opcode)
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{
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op_str = op_print_tab[tem].string;
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break;
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}
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default:
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for (tem = 0; tem < sizeof op_print_tab / sizeof op_print_tab[0]; tem++)
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if (op_print_tab[tem].opcode == opcode)
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{
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op_str = op_print_tab[tem].string;
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myprec = op_print_tab[tem].precedence;
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assoc = op_print_tab[tem].right_assoc;
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break;
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}
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}
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if ((int) myprec < (int) prec)
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fprintf (stream, "(");
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if ((int) opcode > (int) BINOP_END)
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{
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/* Unary prefix operator. */
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fprintf (stream, "%s", op_str);
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print_subexp (exp, pos, stream, PREC_PREFIX);
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}
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else
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{
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/* Binary operator. */
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/* Print left operand.
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If operator is right-associative,
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increment precedence for this operand. */
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print_subexp (exp, pos, stream, (int) myprec + assoc);
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/* Print the operator itself. */
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if (assign_modify)
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fprintf (stream, " %s= ", op_str);
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else if (op_str[0] == ',')
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fprintf (stream, "%s ", op_str);
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else
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fprintf (stream, " %s ", op_str);
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/* Print right operand.
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If operator is left-associative,
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increment precedence for this operand. */
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print_subexp (exp, pos, stream, (int) myprec + !assoc);
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}
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if ((int) myprec < (int) prec)
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fprintf (stream, ")");
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}
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