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Diffstat (limited to 'gdb/expprint.c')
| -rw-r--r-- | gdb/expprint.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/gdb/expprint.c b/gdb/expprint.c new file mode 100644 index 0000000..9e1e9d2 --- /dev/null +++ b/gdb/expprint.c @@ -0,0 +1,324 @@ +/* Print in infix form a struct expression. + Copyright (C) 1986, 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 <stdio.h> +#include "defs.h" +#include "symtab.h" +#include "param.h" +#include "expression.h" +#include "value.h" + + +/* These codes indicate operator precedences, least tightly binding first. */ +/* Adding 1 to a precedence value is done for binary operators, + on the operand which is more tightly bound, so that operators + of equal precedence within that operand will get parentheses. */ +/* PREC_HYPER and PREC_ABOVE_COMMA are not the precedence of any operator; + they are used as the "surrounding precedence" to force + various kinds of things to be parenthesized. */ +enum precedence +{ PREC_NULL, PREC_COMMA, PREC_ABOVE_COMMA, PREC_ASSIGN, PREC_OR, PREC_AND, + PREC_LOGIOR, PREC_LOGAND, PREC_LOGXOR, PREC_EQUAL, PREC_ORDER, + PREC_SHIFT, PREC_ADD, PREC_MUL, PREC_REPEAT, + PREC_HYPER, PREC_PREFIX, PREC_SUFFIX }; + +/* Table mapping opcodes into strings for printing operators + and precedences of the operators. */ + +struct op_print +{ + char *string; + enum exp_opcode opcode; + /* Precedence of operator. These values are used only by comparisons. */ + enum precedence precedence; + int right_assoc; +}; + +static struct op_print op_print_tab[] = + { + {",", BINOP_COMMA, PREC_COMMA, 0}, + {"=", BINOP_ASSIGN, PREC_ASSIGN, 1}, + {"||", BINOP_OR, PREC_OR, 0}, + {"&&", BINOP_AND, PREC_AND, 0}, + {"|", BINOP_LOGIOR, PREC_LOGIOR, 0}, + {"&", BINOP_LOGAND, PREC_LOGAND, 0}, + {"^", BINOP_LOGXOR, PREC_LOGXOR, 0}, + {"==", BINOP_EQUAL, PREC_EQUAL, 0}, + {"!=", BINOP_NOTEQUAL, PREC_EQUAL, 0}, + {"<=", BINOP_LEQ, PREC_ORDER, 0}, + {">=", BINOP_GEQ, PREC_ORDER, 0}, + {">", BINOP_GTR, PREC_ORDER, 0}, + {"<", BINOP_LESS, PREC_ORDER, 0}, + {">>", BINOP_RSH, PREC_SHIFT, 0}, + {"<<", BINOP_LSH, PREC_SHIFT, 0}, + {"+", BINOP_ADD, PREC_ADD, 0}, + {"-", BINOP_SUB, PREC_ADD, 0}, + {"*", BINOP_MUL, PREC_MUL, 0}, + {"/", BINOP_DIV, PREC_MUL, 0}, + {"%", BINOP_REM, PREC_MUL, 0}, + {"@", BINOP_REPEAT, PREC_REPEAT, 0}, + {"-", UNOP_NEG, PREC_PREFIX, 0}, + {"!", UNOP_ZEROP, PREC_PREFIX, 0}, + {"~", UNOP_LOGNOT, PREC_PREFIX, 0}, + {"*", UNOP_IND, PREC_PREFIX, 0}, + {"&", UNOP_ADDR, PREC_PREFIX, 0}, + {"sizeof ", UNOP_SIZEOF, PREC_PREFIX, 0}, + {"++", UNOP_PREINCREMENT, PREC_PREFIX, 0}, + {"--", UNOP_PREDECREMENT, PREC_PREFIX, 0}, + /* C++ */ + {"::", BINOP_SCOPE, PREC_PREFIX, 0}, + }; + +static void print_subexp (); + +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 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; + + pc = (*pos)++; + opcode = exp->elts[pc].opcode; + switch (opcode) + { + case OP_SCOPE: + myprec = PREC_PREFIX; + assoc = 0; + (*pos) += 2; + print_subexp (exp, pos, stream, (int) myprec + assoc); + fprintf (stream, " :: "); + nargs = strlen (&exp->elts[pc + 2].string); + (*pos) += 1 + (nargs + sizeof (union exp_element)) / sizeof (union exp_element); + + fprintf (stream, &exp->elts[pc + 2].string); + return; + + case OP_LONG: + (*pos) += 3; + value_print (value_from_long (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; + fprintf (stream, "%s", SYMBOL_NAME (exp->elts[pc + 1].symbol)); + return; + + case OP_LAST: + (*pos) += 2; + fprintf (stream, "$%d", (int) exp->elts[pc + 1].longconst); + return; + + case OP_REGISTER: + (*pos) += 2; + fprintf (stream, "$%s", reg_names[exp->elts[pc + 1].longconst]); + return; + + case OP_INTERNALVAR: + (*pos) += 2; + fprintf (stream, "$%s", + internalvar_name (exp->elts[pc + 1].internalvar)); + return; + + case OP_FUNCALL: + (*pos) += 2; + nargs = 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 OP_STRING: + nargs = strlen (&exp->elts[pc + 1].string); + (*pos) += 2 + (nargs + sizeof (union exp_element)) / sizeof (union exp_element); + fprintf (stream, "\""); + for (tem = 0; tem < nargs; tem++) + printchar ((&exp->elts[pc + 1].string)[tem], stream, '"'); + fprintf (stream, "\""); + return; + + case TERNOP_COND: + if ((int) prec > (int) PREC_COMMA) + fprintf (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); + fprintf (stream, " ? "); + print_subexp (exp, pos, stream, PREC_HYPER); + fprintf (stream, " : "); + print_subexp (exp, pos, stream, PREC_HYPER); + if ((int) prec > (int) PREC_COMMA) + fprintf (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); + fprintf (stream, ".%s", &exp->elts[pc + 1].string); + return; + + 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); + fprintf (stream, "->%s", &exp->elts[pc + 1].string); + return; + + case BINOP_SUBSCRIPT: + print_subexp (exp, pos, stream, PREC_SUFFIX); + fprintf (stream, "["); + print_subexp (exp, pos, stream, PREC_ABOVE_COMMA); + fprintf (stream, "]"); + return; + + case UNOP_POSTINCREMENT: + print_subexp (exp, pos, stream, PREC_SUFFIX); + fprintf (stream, "++"); + return; + + case UNOP_POSTDECREMENT: + print_subexp (exp, pos, stream, PREC_SUFFIX); + fprintf (stream, "--"); + return; + + case UNOP_CAST: + (*pos) += 2; + if ((int) prec > (int) PREC_PREFIX) + fprintf (stream, "("); + fprintf (stream, "("); + type_print (exp->elts[pc + 1].type, "", stream, 0); + fprintf (stream, ") "); + print_subexp (exp, pos, stream, PREC_PREFIX); + if ((int) prec > (int) PREC_PREFIX) + fprintf (stream, ")"); + return; + + case UNOP_MEMVAL: + (*pos) += 2; + if ((int) prec > (int) PREC_PREFIX) + fprintf (stream, "("); + fprintf (stream, "{"); + type_print (exp->elts[pc + 1].type, "", stream, 0); + fprintf (stream, "} "); + print_subexp (exp, pos, stream, PREC_PREFIX); + if ((int) prec > (int) PREC_PREFIX) + fprintf (stream, ")"); + return; + + case BINOP_ASSIGN_MODIFY: + opcode = exp->elts[pc + 1].opcode; + (*pos) += 2; + myprec = PREC_ASSIGN; + assoc = 1; + assign_modify = 1; + for (tem = 0; tem < sizeof op_print_tab / sizeof op_print_tab[0]; tem++) + if (op_print_tab[tem].opcode == opcode) + { + op_str = op_print_tab[tem].string; + break; + } + + case OP_THIS: + ++(*pos); + fprintf (stream, "this"); + return; + + default: + for (tem = 0; tem < sizeof op_print_tab / sizeof op_print_tab[0]; 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) + fprintf (stream, "("); + if ((int) opcode > (int) BINOP_END) + { + /* Unary prefix operator. */ + fprintf (stream, "%s", op_str); + 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, (int) myprec + assoc); + /* Print the operator itself. */ + if (assign_modify) + fprintf (stream, " %s= ", op_str); + else if (op_str[0] == ',') + fprintf (stream, "%s ", op_str); + else + fprintf (stream, " %s ", op_str); + /* Print right operand. + If operator is left-associative, + increment precedence for this operand. */ + print_subexp (exp, pos, stream, (int) myprec + !assoc); + } + if ((int) myprec < (int) prec) + fprintf (stream, ")"); +} |