Re-instated Guile/Scheme support.

1 files changed, 283 insertions, 0 deletions

diff --git a/gdb/scm-lang.c b/gdb/scm-lang.c
new file mode 100644
index 0000000..02287b8
--- /dev/null
+++ b/gdb/scm-lang.c
@@ -0,0 +1,283 @@
+/* Scheme/Guile language support routines for GDB, the GNU debugger.
+
+   Copyright (C) 1995, 1996, 1998, 2000, 2001, 2002, 2003, 2004, 2005, 2007 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., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#include "defs.h"
+#include "symtab.h"
+#include "gdbtypes.h"
+#include "expression.h"
+#include "parser-defs.h"
+#include "language.h"
+#include "value.h"
+#include "c-lang.h"
+#include "scm-lang.h"
+#include "scm-tags.h"
+#include "source.h"
+#include "gdb_string.h"
+#include "gdbcore.h"
+#include "infcall.h"
+
+extern void _initialize_scheme_language (void);
+static struct value *evaluate_subexp_scm (struct type *, struct expression *,
+				      int *, enum noside);
+static struct value *scm_lookup_name (char *);
+static int in_eval_c (void);
+
+struct type *builtin_type_scm;
+
+void
+scm_printchar (int c, struct ui_file *stream)
+{
+  fprintf_filtered (stream, "#\\%c", c);
+}
+
+static void
+scm_printstr (struct ui_file *stream, const gdb_byte *string,
+	      unsigned int length, int width, int force_ellipses)
+{
+  fprintf_filtered (stream, "\"%s\"", string);
+}
+
+int
+is_scmvalue_type (struct type *type)
+{
+  if (TYPE_NAME (type) && strcmp (TYPE_NAME (type), "SCM") == 0)
+    {
+      return 1;
+    }
+  return 0;
+}
+
+/* Get the INDEX'th SCM value, assuming SVALUE is the address
+   of the 0'th one.  */
+
+LONGEST
+scm_get_field (LONGEST svalue, int index)
+{
+  gdb_byte buffer[20];
+  read_memory (SCM2PTR (svalue) + index * TYPE_LENGTH (builtin_type_scm),
+	       buffer, TYPE_LENGTH (builtin_type_scm));
+  return extract_signed_integer (buffer, TYPE_LENGTH (builtin_type_scm));
+}
+
+/* Unpack a value of type TYPE in buffer VALADDR as an integer
+   (if CONTEXT == TYPE_CODE_IN), a pointer (CONTEXT == TYPE_CODE_PTR),
+   or Boolean (CONTEXT == TYPE_CODE_BOOL).  */
+
+LONGEST
+scm_unpack (struct type *type, const gdb_byte *valaddr, enum type_code context)
+{
+  if (is_scmvalue_type (type))
+    {
+      LONGEST svalue = extract_signed_integer (valaddr, TYPE_LENGTH (type));
+      if (context == TYPE_CODE_BOOL)
+	{
+	  if (svalue == SCM_BOOL_F)
+	    return 0;
+	  else
+	    return 1;
+	}
+      switch (7 & (int) svalue)
+	{
+	case 2:
+	case 6:		/* fixnum */
+	  return svalue >> 2;
+	case 4:		/* other immediate value */
+	  if (SCM_ICHRP (svalue))	/* character */
+	    return SCM_ICHR (svalue);
+	  else if (SCM_IFLAGP (svalue))
+	    {
+	      switch ((int) svalue)
+		{
+#ifndef SICP
+		case SCM_EOL:
+#endif
+		case SCM_BOOL_F:
+		  return 0;
+		case SCM_BOOL_T:
+		  return 1;
+		}
+	    }
+	  error (_("Value can't be converted to integer."));
+	default:
+	  return svalue;
+	}
+    }
+  else
+    return unpack_long (type, valaddr);
+}
+
+/* True if we're correctly in Guile's eval.c (the evaluator and apply). */
+
+static int
+in_eval_c (void)
+{
+  struct symtab_and_line cursal = get_current_source_symtab_and_line ();
+  
+  if (cursal.symtab && cursal.symtab->filename)
+    {
+      char *filename = cursal.symtab->filename;
+      int len = strlen (filename);
+      if (len >= 6 && strcmp (filename + len - 6, "eval.c") == 0)
+	return 1;
+    }
+  return 0;
+}
+
+/* Lookup a value for the variable named STR.
+   First lookup in Scheme context (using the scm_lookup_cstr inferior
+   function), then try lookup_symbol for compiled variables. */
+
+static struct value *
+scm_lookup_name (char *str)
+{
+  struct value *args[3];
+  int len = strlen (str);
+  struct value *func;
+  struct value *val;
+  struct symbol *sym;
+  args[0] = value_allocate_space_in_inferior (len);
+  args[1] = value_from_longest (builtin_type_int, len);
+  write_memory (value_as_long (args[0]), (gdb_byte *) str, len);
+
+  if (in_eval_c ()
+      && (sym = lookup_symbol ("env",
+			       expression_context_block,
+			       VAR_DOMAIN, (int *) NULL,
+			       (struct symtab **) NULL)) != NULL)
+    args[2] = value_of_variable (sym, expression_context_block);
+  else
+    /* FIXME in this case, we should try lookup_symbol first */
+    args[2] = value_from_longest (builtin_type_scm, SCM_EOL);
+
+  func = find_function_in_inferior ("scm_lookup_cstr");
+  val = call_function_by_hand (func, 3, args);
+  if (!value_logical_not (val))
+    return value_ind (val);
+
+  sym = lookup_symbol (str,
+		       expression_context_block,
+		       VAR_DOMAIN, (int *) NULL,
+		       (struct symtab **) NULL);
+  if (sym)
+    return value_of_variable (sym, NULL);
+  error (_("No symbol \"%s\" in current context."), str);
+}
+
+struct value *
+scm_evaluate_string (char *str, int len)
+{
+  struct value *func;
+  struct value *addr = value_allocate_space_in_inferior (len + 1);
+  LONGEST iaddr = value_as_long (addr);
+  write_memory (iaddr, (gdb_byte *) str, len);
+  /* FIXME - should find and pass env */
+  write_memory (iaddr + len, (gdb_byte *) "", 1);
+  func = find_function_in_inferior ("scm_evstr");
+  return call_function_by_hand (func, 1, &addr);
+}
+
+static struct value *
+evaluate_exp (struct type *expect_type, struct expression *exp,
+	      int *pos, enum noside noside)
+{
+  enum exp_opcode op = exp->elts[*pos].opcode;
+  int len, pc;
+  char *str;
+  switch (op)
+    {
+    case OP_NAME:
+      pc = (*pos)++;
+      len = longest_to_int (exp->elts[pc + 1].longconst);
+      (*pos) += 3 + BYTES_TO_EXP_ELEM (len + 1);
+      if (noside == EVAL_SKIP)
+	goto nosideret;
+      str = &exp->elts[pc + 2].string;
+      return scm_lookup_name (str);
+    case OP_STRING:
+      pc = (*pos)++;
+      len = longest_to_int (exp->elts[pc + 1].longconst);
+      (*pos) += 3 + BYTES_TO_EXP_ELEM (len + 1);
+      if (noside == EVAL_SKIP)
+	goto nosideret;
+      str = &exp->elts[pc + 2].string;
+      return scm_evaluate_string (str, len);
+    default:;
+    }
+  return evaluate_subexp_standard (expect_type, exp, pos, noside);
+nosideret:
+  return value_from_longest (builtin_type_long, (LONGEST) 1);
+}
+
+const struct exp_descriptor exp_descriptor_scm = 
+{
+  print_subexp_standard,
+  operator_length_standard,
+  op_name_standard,
+  dump_subexp_body_standard,
+  evaluate_exp
+};
+
+const struct language_defn scm_language_defn =
+{
+  "scheme",			/* Language name */
+  language_scm,
+  NULL,
+  range_check_off,
+  type_check_off,
+  case_sensitive_off,
+  array_row_major,
+  &exp_descriptor_scm,
+  scm_parse,
+  c_error,
+  null_post_parser,
+  scm_printchar,		/* Print a character constant */
+  scm_printstr,			/* Function to print string constant */
+  NULL,				/* Function to print a single character */
+  NULL,				/* Create fundamental type in this language */
+  c_print_type,			/* Print a type using appropriate syntax */
+  scm_val_print,		/* Print a value using appropriate syntax */
+  scm_value_print,		/* Print a top-level value */
+  NULL,				/* Language specific skip_trampoline */
+  value_of_this,		/* value_of_this */
+  basic_lookup_symbol_nonlocal,	/* lookup_symbol_nonlocal */
+  basic_lookup_transparent_type,/* lookup_transparent_type */
+  NULL,				/* Language specific symbol demangler */
+  NULL,				/* Language specific class_name_from_physname */
+  NULL,				/* expression operators for printing */
+  1,				/* c-style arrays */
+  0,				/* String lower bound */
+  NULL,
+  default_word_break_characters,
+  c_language_arch_info,
+  default_print_array_index,
+  LANG_MAGIC
+};
+
+void
+_initialize_scheme_language (void)
+{
+  add_language (&scm_language_defn);
+  builtin_type_scm =
+    init_type (TYPE_CODE_INT,
+	       gdbarch_long_bit (current_gdbarch) / TARGET_CHAR_BIT,
+	       0, "SCM", (struct objfile *) NULL);
+}