1/* Scheme/Guile language support routines for GDB, the GNU debugger.
2
3   Copyright 1995, 1996, 1998, 2000, 2001, 2002, 2003, 2004 Free Software
4   Foundation, Inc.
5
6   This file is part of GDB.
7
8   This program is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 2 of the License, or
11   (at your option) any later version.
12
13   This program is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with this program; if not, write to the Free Software
20   Foundation, Inc., 59 Temple Place - Suite 330,
21   Boston, MA 02111-1307, USA.  */
22
23#include "defs.h"
24#include "symtab.h"
25#include "gdbtypes.h"
26#include "expression.h"
27#include "parser-defs.h"
28#include "language.h"
29#include "value.h"
30#include "c-lang.h"
31#include "scm-lang.h"
32#include "scm-tags.h"
33#include "source.h"
34#include "gdb_string.h"
35#include "gdbcore.h"
36#include "infcall.h"
37
38extern void _initialize_scheme_language (void);
39static struct value *evaluate_subexp_scm (struct type *, struct expression *,
40				      int *, enum noside);
41static struct value *scm_lookup_name (char *);
42static int in_eval_c (void);
43static void scm_printstr (struct ui_file * stream, char *string,
44			  unsigned int length, int width,
45			  int force_ellipses);
46
47extern struct type **const (c_builtin_types[]);
48
49struct type *builtin_type_scm;
50
51void
52scm_printchar (int c, struct ui_file *stream)
53{
54  fprintf_filtered (stream, "#\\%c", c);
55}
56
57static void
58scm_printstr (struct ui_file *stream, char *string, unsigned int length,
59	      int width, int force_ellipses)
60{
61  fprintf_filtered (stream, "\"%s\"", string);
62}
63
64int
65is_scmvalue_type (struct type *type)
66{
67  if (TYPE_CODE (type) == TYPE_CODE_INT
68      && TYPE_NAME (type) && strcmp (TYPE_NAME (type), "SCM") == 0)
69    {
70      return 1;
71    }
72  return 0;
73}
74
75/* Get the INDEX'th SCM value, assuming SVALUE is the address
76   of the 0'th one.  */
77
78LONGEST
79scm_get_field (LONGEST svalue, int index)
80{
81  char buffer[20];
82  read_memory (SCM2PTR (svalue) + index * TYPE_LENGTH (builtin_type_scm),
83	       buffer, TYPE_LENGTH (builtin_type_scm));
84  return extract_signed_integer (buffer, TYPE_LENGTH (builtin_type_scm));
85}
86
87/* Unpack a value of type TYPE in buffer VALADDR as an integer
88   (if CONTEXT == TYPE_CODE_IN), a pointer (CONTEXT == TYPE_CODE_PTR),
89   or Boolean (CONTEXT == TYPE_CODE_BOOL).  */
90
91LONGEST
92scm_unpack (struct type *type, const char *valaddr, enum type_code context)
93{
94  if (is_scmvalue_type (type))
95    {
96      LONGEST svalue = extract_signed_integer (valaddr, TYPE_LENGTH (type));
97      if (context == TYPE_CODE_BOOL)
98	{
99	  if (svalue == SCM_BOOL_F)
100	    return 0;
101	  else
102	    return 1;
103	}
104      switch (7 & (int) svalue)
105	{
106	case 2:
107	case 6:		/* fixnum */
108	  return svalue >> 2;
109	case 4:		/* other immediate value */
110	  if (SCM_ICHRP (svalue))	/* character */
111	    return SCM_ICHR (svalue);
112	  else if (SCM_IFLAGP (svalue))
113	    {
114	      switch ((int) svalue)
115		{
116#ifndef SICP
117		case SCM_EOL:
118#endif
119		case SCM_BOOL_F:
120		  return 0;
121		case SCM_BOOL_T:
122		  return 1;
123		}
124	    }
125	  error ("Value can't be converted to integer.");
126	default:
127	  return svalue;
128	}
129    }
130  else
131    return unpack_long (type, valaddr);
132}
133
134/* True if we're correctly in Guile's eval.c (the evaluator and apply). */
135
136static int
137in_eval_c (void)
138{
139  struct symtab_and_line cursal = get_current_source_symtab_and_line ();
140
141  if (cursal.symtab && cursal.symtab->filename)
142    {
143      char *filename = cursal.symtab->filename;
144      int len = strlen (filename);
145      if (len >= 6 && strcmp (filename + len - 6, "eval.c") == 0)
146	return 1;
147    }
148  return 0;
149}
150
151/* Lookup a value for the variable named STR.
152   First lookup in Scheme context (using the scm_lookup_cstr inferior
153   function), then try lookup_symbol for compiled variables. */
154
155static struct value *
156scm_lookup_name (char *str)
157{
158  struct value *args[3];
159  int len = strlen (str);
160  struct value *func;
161  struct value *val;
162  struct symbol *sym;
163  args[0] = value_allocate_space_in_inferior (len);
164  args[1] = value_from_longest (builtin_type_int, len);
165  write_memory (value_as_long (args[0]), str, len);
166
167  if (in_eval_c ()
168      && (sym = lookup_symbol ("env",
169			       expression_context_block,
170			       VAR_DOMAIN, (int *) NULL,
171			       (struct symtab **) NULL)) != NULL)
172    args[2] = value_of_variable (sym, expression_context_block);
173  else
174    /* FIXME in this case, we should try lookup_symbol first */
175    args[2] = value_from_longest (builtin_type_scm, SCM_EOL);
176
177  func = find_function_in_inferior ("scm_lookup_cstr");
178  val = call_function_by_hand (func, 3, args);
179  if (!value_logical_not (val))
180    return value_ind (val);
181
182  sym = lookup_symbol (str,
183		       expression_context_block,
184		       VAR_DOMAIN, (int *) NULL,
185		       (struct symtab **) NULL);
186  if (sym)
187    return value_of_variable (sym, NULL);
188  error ("No symbol \"%s\" in current context.", str);
189}
190
191struct value *
192scm_evaluate_string (char *str, int len)
193{
194  struct value *func;
195  struct value *addr = value_allocate_space_in_inferior (len + 1);
196  LONGEST iaddr = value_as_long (addr);
197  write_memory (iaddr, str, len);
198  /* FIXME - should find and pass env */
199  write_memory (iaddr + len, "", 1);
200  func = find_function_in_inferior ("scm_evstr");
201  return call_function_by_hand (func, 1, &addr);
202}
203
204static struct value *
205evaluate_subexp_scm (struct type *expect_type, struct expression *exp,
206		     int *pos, enum noside noside)
207{
208  enum exp_opcode op = exp->elts[*pos].opcode;
209  int len, pc;
210  char *str;
211  switch (op)
212    {
213    case OP_NAME:
214      pc = (*pos)++;
215      len = longest_to_int (exp->elts[pc + 1].longconst);
216      (*pos) += 3 + BYTES_TO_EXP_ELEM (len + 1);
217      if (noside == EVAL_SKIP)
218	goto nosideret;
219      str = &exp->elts[pc + 2].string;
220      return scm_lookup_name (str);
221    case OP_EXPRSTRING:
222      pc = (*pos)++;
223      len = longest_to_int (exp->elts[pc + 1].longconst);
224      (*pos) += 3 + BYTES_TO_EXP_ELEM (len + 1);
225      if (noside == EVAL_SKIP)
226	goto nosideret;
227      str = &exp->elts[pc + 2].string;
228      return scm_evaluate_string (str, len);
229    default:;
230    }
231  return evaluate_subexp_standard (expect_type, exp, pos, noside);
232nosideret:
233  return value_from_longest (builtin_type_long, (LONGEST) 1);
234}
235
236const struct exp_descriptor exp_descriptor_scm =
237{
238  print_subexp_standard,
239  operator_length_standard,
240  op_name_standard,
241  dump_subexp_body_standard,
242  evaluate_subexp_scm
243};
244
245const struct language_defn scm_language_defn =
246{
247  "scheme",			/* Language name */
248  language_scm,
249  c_builtin_types,
250  range_check_off,
251  type_check_off,
252  case_sensitive_off,
253  &exp_descriptor_scm,
254  scm_parse,
255  c_error,
256  scm_printchar,		/* Print a character constant */
257  scm_printstr,			/* Function to print string constant */
258  NULL,				/* Function to print a single character */
259  NULL,				/* Create fundamental type in this language */
260  c_print_type,			/* Print a type using appropriate syntax */
261  scm_val_print,		/* Print a value using appropriate syntax */
262  scm_value_print,		/* Print a top-level value */
263  NULL,				/* Language specific skip_trampoline */
264  value_of_this,		/* value_of_this */
265  basic_lookup_symbol_nonlocal,	/* lookup_symbol_nonlocal */
266  basic_lookup_transparent_type,/* lookup_transparent_type */
267  NULL,				/* Language specific symbol demangler */
268  {"", "", "", ""},		/* Binary format info */
269  {"#o%lo", "#o", "o", ""},	/* Octal format info */
270  {"%ld", "", "d", ""},		/* Decimal format info */
271  {"#x%lX", "#X", "X", ""},	/* Hex format info */
272  NULL,				/* expression operators for printing */
273  1,				/* c-style arrays */
274  0,				/* String lower bound */
275  &builtin_type_char,		/* Type of string elements */
276  default_word_break_characters,
277  LANG_MAGIC
278};
279
280void
281_initialize_scheme_language (void)
282{
283  add_language (&scm_language_defn);
284  builtin_type_scm = init_type (TYPE_CODE_INT,
285				TARGET_LONG_BIT / TARGET_CHAR_BIT,
286				0, "SCM", (struct objfile *) NULL);
287}
288