4.4BSD/usr/src/contrib/gdb-4.7.lbl/gdb/expprint.c
/* Print in infix form a struct expression.
Copyright (C) 1986, 1989, 1991 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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "value.h"
#include "language.h"
#include "parser-defs.h"
/* Prototypes for local functions */
static void
print_subexp PARAMS ((struct expression *, int *, FILE *, enum precedence));
static void
print_simple_m2_func PARAMS ((char *, struct expression *, int *, FILE *));
void
print_expression (exp, stream)
struct expression *exp;
FILE *stream;
{
int pc = 0;
print_subexp (exp, &pc, stream, PREC_NULL);
}
/* Print the subexpression of EXP that starts in position POS, on STREAM.
PREC is the precedence of the surrounding operator;
if the precedence of the main operator of this subexpression is less,
parentheses are needed here. */
static void
print_subexp (exp, pos, stream, prec)
register struct expression *exp;
register int *pos;
FILE *stream;
enum precedence prec;
{
register unsigned tem;
register const struct op_print *op_print_tab;
register int pc;
unsigned nargs;
register char *op_str;
int assign_modify = 0;
enum exp_opcode opcode;
enum precedence myprec;
/* Set to 1 for a right-associative operator. */
int assoc;
value val;
op_print_tab = exp->language_defn->la_op_print_tab;
pc = (*pos)++;
opcode = exp->elts[pc].opcode;
switch (opcode)
{
/* Common ops */
case OP_SCOPE:
myprec = PREC_PREFIX;
assoc = 0;
(*pos) += 2;
print_subexp (exp, pos, stream,
(enum precedence) ((int) myprec + assoc));
fputs_filtered (" :: ", stream);
nargs = strlen (&exp->elts[pc + 2].string);
(*pos) += 1 + (nargs + sizeof (union exp_element)) / sizeof (union exp_element);
fputs_filtered (&exp->elts[pc + 2].string, stream);
return;
case OP_LONG:
(*pos) += 3;
value_print (value_from_longest (exp->elts[pc + 1].type,
exp->elts[pc + 2].longconst),
stream, 0, Val_no_prettyprint);
return;
case OP_DOUBLE:
(*pos) += 3;
value_print (value_from_double (exp->elts[pc + 1].type,
exp->elts[pc + 2].doubleconst),
stream, 0, Val_no_prettyprint);
return;
case OP_VAR_VALUE:
(*pos) += 2;
fputs_filtered (SYMBOL_NAME (exp->elts[pc + 1].symbol), stream);
return;
case OP_LAST:
(*pos) += 2;
fprintf_filtered (stream, "$%d",
longest_to_int (exp->elts[pc + 1].longconst));
return;
case OP_REGISTER:
(*pos) += 2;
fprintf_filtered (stream, "$%s",
reg_names[longest_to_int (exp->elts[pc + 1].longconst)]);
return;
case OP_INTERNALVAR:
(*pos) += 2;
fprintf_filtered (stream, "$%s",
internalvar_name (exp->elts[pc + 1].internalvar));
return;
case OP_FUNCALL:
(*pos) += 2;
nargs = longest_to_int (exp->elts[pc + 1].longconst);
print_subexp (exp, pos, stream, PREC_SUFFIX);
fputs_filtered (" (", stream);
for (tem = 0; tem < nargs; tem++)
{
if (tem != 0)
fputs_filtered (", ", stream);
print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
}
fputs_filtered (")", stream);
return;
case OP_STRING:
nargs = strlen (&exp->elts[pc + 1].string);
(*pos) += 2 + (nargs + sizeof (union exp_element)) / sizeof (union exp_element);
fputs_filtered ("\"", stream);
for (tem = 0; tem < nargs; tem++)
printchar ((&exp->elts[pc + 1].string)[tem], stream, '"');
fputs_filtered ("\"", stream);
return;
case TERNOP_COND:
if ((int) prec > (int) PREC_COMMA)
fputs_filtered ("(", stream);
/* Print the subexpressions, forcing parentheses
around any binary operations within them.
This is more parentheses than are strictly necessary,
but it looks clearer. */
print_subexp (exp, pos, stream, PREC_HYPER);
fputs_filtered (" ? ", stream);
print_subexp (exp, pos, stream, PREC_HYPER);
fputs_filtered (" : ", stream);
print_subexp (exp, pos, stream, PREC_HYPER);
if ((int) prec > (int) PREC_COMMA)
fputs_filtered (")", stream);
return;
case STRUCTOP_STRUCT:
tem = strlen (&exp->elts[pc + 1].string);
(*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element);
print_subexp (exp, pos, stream, PREC_SUFFIX);
fputs_filtered (".", stream);
fputs_filtered (&exp->elts[pc + 1].string, stream);
return;
/* Will not occur for Modula-2 */
case STRUCTOP_PTR:
tem = strlen (&exp->elts[pc + 1].string);
(*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element);
print_subexp (exp, pos, stream, PREC_SUFFIX);
fputs_filtered ("->", stream);
fputs_filtered (&exp->elts[pc + 1].string, stream);
return;
case BINOP_SUBSCRIPT:
print_subexp (exp, pos, stream, PREC_SUFFIX);
fputs_filtered ("[", stream);
print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
fputs_filtered ("]", stream);
return;
case UNOP_POSTINCREMENT:
print_subexp (exp, pos, stream, PREC_SUFFIX);
fputs_filtered ("++", stream);
return;
case UNOP_POSTDECREMENT:
print_subexp (exp, pos, stream, PREC_SUFFIX);
fputs_filtered ("--", stream);
return;
case UNOP_CAST:
(*pos) += 2;
if ((int) prec > (int) PREC_PREFIX)
fputs_filtered ("(", stream);
fputs_filtered ("(", stream);
type_print (exp->elts[pc + 1].type, "", stream, 0);
fputs_filtered (") ", stream);
print_subexp (exp, pos, stream, PREC_PREFIX);
if ((int) prec > (int) PREC_PREFIX)
fputs_filtered (")", stream);
return;
case UNOP_MEMVAL:
(*pos) += 2;
if ((int) prec > (int) PREC_PREFIX)
fputs_filtered ("(", stream);
if (exp->elts[pc + 1].type->code == TYPE_CODE_FUNC &&
exp->elts[pc + 3].opcode == OP_LONG) {
/* We have a minimal symbol fn, probably. It's encoded
as a UNOP_MEMVAL (function-type) of an OP_LONG (int, address).
Swallow the OP_LONG (including both its opcodes); ignore
its type; print the value in the type of the MEMVAL. */
(*pos) += 4;
val = value_at_lazy (exp->elts[pc + 1].type,
(CORE_ADDR) exp->elts[pc + 5].longconst);
value_print (val, stream, 0, Val_no_prettyprint);
} else {
fputs_filtered ("{", stream);
type_print (exp->elts[pc + 1].type, "", stream, 0);
fputs_filtered ("} ", stream);
print_subexp (exp, pos, stream, PREC_PREFIX);
}
if ((int) prec > (int) PREC_PREFIX)
fputs_filtered (")", stream);
return;
case BINOP_ASSIGN_MODIFY:
opcode = exp->elts[pc + 1].opcode;
(*pos) += 2;
myprec = PREC_ASSIGN;
assoc = 1;
assign_modify = 1;
op_str = "???";
for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
if (op_print_tab[tem].opcode == opcode)
{
op_str = op_print_tab[tem].string;
break;
}
break;
/* C++ ops */
case OP_THIS:
++(*pos);
fputs_filtered ("this", stream);
return;
/* Modula-2 ops */
case BINOP_MULTI_SUBSCRIPT:
(*pos) += 2;
nargs = longest_to_int (exp->elts[pc + 1].longconst);
print_subexp (exp, pos, stream, PREC_SUFFIX);
fprintf (stream, " [");
for (tem = 0; tem < nargs; tem++)
{
if (tem != 0)
fprintf (stream, ", ");
print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
}
fprintf (stream, "]");
return;
case BINOP_VAL:
(*pos)+=2;
fprintf(stream,"VAL(");
type_print(exp->elts[pc+1].type,"",stream,0);
fprintf(stream,",");
print_subexp(exp,pos,stream,PREC_PREFIX);
fprintf(stream,")");
return;
case UNOP_CAP:
print_simple_m2_func("CAP",exp,pos,stream);
return;
case UNOP_CHR:
print_simple_m2_func("CHR",exp,pos,stream);
return;
case UNOP_ORD:
print_simple_m2_func("ORD",exp,pos,stream);
return;
case UNOP_ABS:
print_simple_m2_func("ABS",exp,pos,stream);
return;
case UNOP_FLOAT:
print_simple_m2_func("FLOAT",exp,pos,stream);
return;
case UNOP_HIGH:
print_simple_m2_func("HIGH",exp,pos,stream);
return;
case UNOP_MAX:
print_simple_m2_func("MAX",exp,pos,stream);
return;
case UNOP_MIN:
print_simple_m2_func("MIN",exp,pos,stream);
return;
case UNOP_ODD:
print_simple_m2_func("ODD",exp,pos,stream);
return;
case UNOP_TRUNC:
print_simple_m2_func("TRUNC",exp,pos,stream);
return;
case BINOP_INCL:
case BINOP_EXCL:
error("print_subexp: Not implemented.");
/* Default ops */
default:
op_str = "???";
for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
if (op_print_tab[tem].opcode == opcode)
{
op_str = op_print_tab[tem].string;
myprec = op_print_tab[tem].precedence;
assoc = op_print_tab[tem].right_assoc;
break;
}
}
if ((int) myprec < (int) prec)
fputs_filtered ("(", stream);
if ((int) opcode > (int) BINOP_END)
{
/* Unary prefix operator. */
fputs_filtered (op_str, stream);
print_subexp (exp, pos, stream, PREC_PREFIX);
}
else
{
/* Binary operator. */
/* Print left operand.
If operator is right-associative,
increment precedence for this operand. */
print_subexp (exp, pos, stream,
(enum precedence) ((int) myprec + assoc));
/* Print the operator itself. */
if (assign_modify)
fprintf_filtered (stream, " %s= ", op_str);
else if (op_str[0] == ',')
fprintf_filtered (stream, "%s ", op_str);
else
fprintf_filtered (stream, " %s ", op_str);
/* Print right operand.
If operator is left-associative,
increment precedence for this operand. */
print_subexp (exp, pos, stream,
(enum precedence) ((int) myprec + !assoc));
}
if ((int) myprec < (int) prec)
fputs_filtered (")", stream);
}
/* Print out something of the form <s>(<arg>).
This is used to print out some builtin Modula-2
functions.
FIXME: There is probably some way to get the precedence
rules to do this (print a unary operand with parens around it). */
static void
print_simple_m2_func(s,exp,pos,stream)
char *s;
register struct expression *exp;
register int *pos;
FILE *stream;
{
fprintf(stream,"%s(",s);
print_subexp(exp,pos,stream,PREC_PREFIX);
fprintf(stream,")");
}
/* Return the operator corresponding to opcode OP as
a string. NULL indicates that the opcode was not found in the
current language table. */
char *
op_string(op)
enum exp_opcode op;
{
int tem;
register const struct op_print *op_print_tab;
op_print_tab = current_language->la_op_print_tab;
for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
if (op_print_tab[tem].opcode == op)
return op_print_tab[tem].string;
return NULL;
}