1 /* Scheme/Guile language support routines for GDB, the GNU debugger.
2
3 Copyright 1995, 1996, 1998, 2000, 2001, 2002, 2003, 2004, 2005 Free
4 Software 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
38 extern void _initialize_scheme_language (void);
39 static struct value *evaluate_subexp_scm (struct type *, struct expression *,
40 int *, enum noside);
41 static struct value *scm_lookup_name (char *);
42 static int in_eval_c (void);
43
44 struct type *builtin_type_scm;
45
46 void
scm_printchar(int c,struct ui_file * stream)47 scm_printchar (int c, struct ui_file *stream)
48 {
49 fprintf_filtered (stream, "#\\%c", c);
50 }
51
52 static void
scm_printstr(struct ui_file * stream,const gdb_byte * string,unsigned int length,int width,int force_ellipses)53 scm_printstr (struct ui_file *stream, const gdb_byte *string,
54 unsigned int length, int width, int force_ellipses)
55 {
56 fprintf_filtered (stream, "\"%s\"", string);
57 }
58
59 int
is_scmvalue_type(struct type * type)60 is_scmvalue_type (struct type *type)
61 {
62 if (TYPE_CODE (type) == TYPE_CODE_INT
63 && TYPE_NAME (type) && strcmp (TYPE_NAME (type), "SCM") == 0)
64 {
65 return 1;
66 }
67 return 0;
68 }
69
70 /* Get the INDEX'th SCM value, assuming SVALUE is the address
71 of the 0'th one. */
72
73 LONGEST
scm_get_field(LONGEST svalue,int index)74 scm_get_field (LONGEST svalue, int index)
75 {
76 gdb_byte buffer[20];
77 read_memory (SCM2PTR (svalue) + index * TYPE_LENGTH (builtin_type_scm),
78 buffer, TYPE_LENGTH (builtin_type_scm));
79 return extract_signed_integer (buffer, TYPE_LENGTH (builtin_type_scm));
80 }
81
82 /* Unpack a value of type TYPE in buffer VALADDR as an integer
83 (if CONTEXT == TYPE_CODE_IN), a pointer (CONTEXT == TYPE_CODE_PTR),
84 or Boolean (CONTEXT == TYPE_CODE_BOOL). */
85
86 LONGEST
scm_unpack(struct type * type,const gdb_byte * valaddr,enum type_code context)87 scm_unpack (struct type *type, const gdb_byte *valaddr, enum type_code context)
88 {
89 if (is_scmvalue_type (type))
90 {
91 LONGEST svalue = extract_signed_integer (valaddr, TYPE_LENGTH (type));
92 if (context == TYPE_CODE_BOOL)
93 {
94 if (svalue == SCM_BOOL_F)
95 return 0;
96 else
97 return 1;
98 }
99 switch (7 & (int) svalue)
100 {
101 case 2:
102 case 6: /* fixnum */
103 return svalue >> 2;
104 case 4: /* other immediate value */
105 if (SCM_ICHRP (svalue)) /* character */
106 return SCM_ICHR (svalue);
107 else if (SCM_IFLAGP (svalue))
108 {
109 switch ((int) svalue)
110 {
111 #ifndef SICP
112 case SCM_EOL:
113 #endif
114 case SCM_BOOL_F:
115 return 0;
116 case SCM_BOOL_T:
117 return 1;
118 }
119 }
120 error (_("Value can't be converted to integer."));
121 default:
122 return svalue;
123 }
124 }
125 else
126 return unpack_long (type, valaddr);
127 }
128
129 /* True if we're correctly in Guile's eval.c (the evaluator and apply). */
130
131 static int
in_eval_c(void)132 in_eval_c (void)
133 {
134 struct symtab_and_line cursal = get_current_source_symtab_and_line ();
135
136 if (cursal.symtab && cursal.symtab->filename)
137 {
138 char *filename = cursal.symtab->filename;
139 int len = strlen (filename);
140 if (len >= 6 && strcmp (filename + len - 6, "eval.c") == 0)
141 return 1;
142 }
143 return 0;
144 }
145
146 /* Lookup a value for the variable named STR.
147 First lookup in Scheme context (using the scm_lookup_cstr inferior
148 function), then try lookup_symbol for compiled variables. */
149
150 static struct value *
scm_lookup_name(char * str)151 scm_lookup_name (char *str)
152 {
153 struct value *args[3];
154 int len = strlen (str);
155 struct value *func;
156 struct value *val;
157 struct symbol *sym;
158 args[0] = value_allocate_space_in_inferior (len);
159 args[1] = value_from_longest (builtin_type_int, len);
160 write_memory (value_as_long (args[0]), (gdb_byte *) str, len);
161
162 if (in_eval_c ()
163 && (sym = lookup_symbol ("env",
164 expression_context_block,
165 VAR_DOMAIN, (int *) NULL,
166 (struct symtab **) NULL)) != NULL)
167 args[2] = value_of_variable (sym, expression_context_block);
168 else
169 /* FIXME in this case, we should try lookup_symbol first */
170 args[2] = value_from_longest (builtin_type_scm, SCM_EOL);
171
172 func = find_function_in_inferior ("scm_lookup_cstr");
173 val = call_function_by_hand (func, 3, args);
174 if (!value_logical_not (val))
175 return value_ind (val);
176
177 sym = lookup_symbol (str,
178 expression_context_block,
179 VAR_DOMAIN, (int *) NULL,
180 (struct symtab **) NULL);
181 if (sym)
182 return value_of_variable (sym, NULL);
183 error (_("No symbol \"%s\" in current context."), str);
184 }
185
186 struct value *
scm_evaluate_string(char * str,int len)187 scm_evaluate_string (char *str, int len)
188 {
189 struct value *func;
190 struct value *addr = value_allocate_space_in_inferior (len + 1);
191 LONGEST iaddr = value_as_long (addr);
192 write_memory (iaddr, (gdb_byte *) str, len);
193 /* FIXME - should find and pass env */
194 write_memory (iaddr + len, (gdb_byte *) "", 1);
195 func = find_function_in_inferior ("scm_evstr");
196 return call_function_by_hand (func, 1, &addr);
197 }
198
199 static struct value *
evaluate_subexp_scm(struct type * expect_type,struct expression * exp,int * pos,enum noside noside)200 evaluate_subexp_scm (struct type *expect_type, struct expression *exp,
201 int *pos, enum noside noside)
202 {
203 enum exp_opcode op = exp->elts[*pos].opcode;
204 int len, pc;
205 char *str;
206 switch (op)
207 {
208 case OP_NAME:
209 pc = (*pos)++;
210 len = longest_to_int (exp->elts[pc + 1].longconst);
211 (*pos) += 3 + BYTES_TO_EXP_ELEM (len + 1);
212 if (noside == EVAL_SKIP)
213 goto nosideret;
214 str = &exp->elts[pc + 2].string;
215 return scm_lookup_name (str);
216 case OP_EXPRSTRING:
217 pc = (*pos)++;
218 len = longest_to_int (exp->elts[pc + 1].longconst);
219 (*pos) += 3 + BYTES_TO_EXP_ELEM (len + 1);
220 if (noside == EVAL_SKIP)
221 goto nosideret;
222 str = &exp->elts[pc + 2].string;
223 return scm_evaluate_string (str, len);
224 default:;
225 }
226 return evaluate_subexp_standard (expect_type, exp, pos, noside);
227 nosideret:
228 return value_from_longest (builtin_type_long, (LONGEST) 1);
229 }
230
231 const struct exp_descriptor exp_descriptor_scm =
232 {
233 print_subexp_standard,
234 operator_length_standard,
235 op_name_standard,
236 dump_subexp_body_standard,
237 evaluate_subexp_scm
238 };
239
240 const struct language_defn scm_language_defn =
241 {
242 "scheme", /* Language name */
243 language_scm,
244 NULL,
245 range_check_off,
246 type_check_off,
247 case_sensitive_off,
248 array_row_major,
249 &exp_descriptor_scm,
250 scm_parse,
251 c_error,
252 null_post_parser,
253 scm_printchar, /* Print a character constant */
254 scm_printstr, /* Function to print string constant */
255 NULL, /* Function to print a single character */
256 NULL, /* Create fundamental type in this language */
257 c_print_type, /* Print a type using appropriate syntax */
258 scm_val_print, /* Print a value using appropriate syntax */
259 scm_value_print, /* Print a top-level value */
260 NULL, /* Language specific skip_trampoline */
261 value_of_this, /* value_of_this */
262 basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
263 basic_lookup_transparent_type,/* lookup_transparent_type */
264 NULL, /* Language specific symbol demangler */
265 NULL, /* Language specific class_name_from_physname */
266 NULL, /* expression operators for printing */
267 1, /* c-style arrays */
268 0, /* String lower bound */
269 NULL,
270 default_word_break_characters,
271 c_language_arch_info,
272 LANG_MAGIC
273 };
274
275 void
_initialize_scheme_language(void)276 _initialize_scheme_language (void)
277 {
278 add_language (&scm_language_defn);
279 builtin_type_scm = init_type (TYPE_CODE_INT,
280 TARGET_LONG_BIT / TARGET_CHAR_BIT,
281 0, "SCM", (struct objfile *) NULL);
282 }
283