symtab.c

早期freebsd实现

   *EXPR -- line in which address EXPR appears.

   FUNCTION may be an undebuggable function found in minimal symbol table.

   If the argument FUNFIRSTLINE is nonzero, we want the first line
   of real code inside a function when a function is specified.

   DEFAULT_SYMTAB specifies the file to use if none is specified.
   It defaults to current_source_symtab.
   DEFAULT_LINE specifies the line number to use for relative
   line numbers (that start with signs).  Defaults to current_source_line.

   Note that it is possible to return zero for the symtab
   if no file is validly specified.  Callers must check that.
   Also, the line number returned may be invalid.  */

struct symtabs_and_lines
decode_line_1 (argptr, funfirstline, default_symtab, default_line)
     char **argptr;
     int funfirstline;
     struct symtab *default_symtab;
     int default_line;
{
  struct symtabs_and_lines values;
#ifdef HPPA_COMPILER_BUG
  /* FIXME: The native HP 9000/700 compiler has a bug which appears
     when optimizing this file with target i960-vxworks.  I haven't
     been able to construct a simple test case.  The problem is that
     in the second call to SKIP_PROLOGUE below, the compiler somehow
     does not realize that the statement val = find_pc_line (...) will
     change the values of the fields of val.  It extracts the elements
     into registers at the top of the block, and does not update the
     registers after the call to find_pc_line.  You can check this by
     inserting a printf at the end of find_pc_line to show what values
     it is returning for val.pc and val.end and another printf after
     the call to see what values the function actually got (remember,
     this is compiling with cc -O, with this patch removed).  You can
     also examine the assembly listing: search for the second call to
     skip_prologue; the LDO statement before the next call to
     find_pc_line loads the address of the structure which
     find_pc_line will return; if there is a LDW just before the LDO,
     which fetches an element of the structure, then the compiler
     still has the bug.

     Setting val to volatile avoids the problem.  We must undef
     volatile, because the HPPA native compiler does not define
     __STDC__, although it does understand volatile, and so volatile
     will have been defined away in defs.h.  */
#undef volatile
  volatile struct symtab_and_line val;
#define volatile /*nothing*/
#else
  struct symtab_and_line val;
#endif
  register char *p, *p1;
  char *q, *q1;
  register struct symtab *s;

  register struct symbol *sym;
  /* The symtab that SYM was found in.  */
  struct symtab *sym_symtab;

  register CORE_ADDR pc;
  register struct minimal_symbol *msymbol;
  char *copy;
  struct symbol *sym_class;
  int i1;
  int is_quoted;
  struct symbol **sym_arr;
  struct type *t;
  char **physnames;
  char *saved_arg = *argptr;
  extern char *gdb_completer_quote_characters;
  
  /* Defaults have defaults.  */

  if (default_symtab == 0)
    {
      default_symtab = current_source_symtab;
      default_line = current_source_line;
    }

  /* See if arg is *PC */

  if (**argptr == '*')
    {
      if (**argptr == '*')
	{
	  (*argptr)++;
	}
      pc = parse_and_eval_address_1 (argptr);
      values.sals = (struct symtab_and_line *)
	xmalloc (sizeof (struct symtab_and_line));
      values.nelts = 1;
      values.sals[0] = find_pc_line (pc, 0);
      values.sals[0].pc = pc;
      return values;
    }

  /* Maybe arg is FILE : LINENUM or FILE : FUNCTION */

  s = NULL;
  is_quoted = (strchr (gdb_completer_quote_characters, **argptr) != NULL);

  for (p = *argptr; *p; p++)
    {
      if (p[0] == ':' || p[0] == ' ' || p[0] == '\t')
	break;
    }
  while (p[0] == ' ' || p[0] == '\t') p++;

  if ((p[0] == ':') && !is_quoted)
    {

      /*  C++  */
      if (p[1] ==':')
	{
	  /* Extract the class name.  */
	  p1 = p;
	  while (p != *argptr && p[-1] == ' ') --p;
	  copy = (char *) alloca (p - *argptr + 1);
	  memcpy (copy, *argptr, p - *argptr);
	  copy[p - *argptr] = 0;

	  /* Discard the class name from the arg.  */
	  p = p1 + 2;
	  while (*p == ' ' || *p == '\t') p++;
	  *argptr = p;

	  sym_class = lookup_symbol (copy, 0, STRUCT_NAMESPACE, 0, 
				     (struct symtab **)NULL);
       
	  if (sym_class &&
	      (   TYPE_CODE (SYMBOL_TYPE (sym_class)) == TYPE_CODE_STRUCT
	       || TYPE_CODE (SYMBOL_TYPE (sym_class)) == TYPE_CODE_UNION))
	    {
	      /* Arg token is not digits => try it as a function name
		 Find the next token (everything up to end or next whitespace). */
	      p = *argptr;
	      while (*p && *p != ' ' && *p != '\t' && *p != ',' && *p !=':') p++;
	      q = operator_chars (*argptr, &q1);

	      if (q1 - q)
		{
		  char *opname;
		  char *tmp = alloca (q1 - q + 1);
		  memcpy (tmp, q, q1 - q);
		  tmp[q1 - q] = '\0';
		  opname = cplus_mangle_opname (tmp, DMGL_ANSI);
		  if (opname == NULL)
		    {
		      warning ("no mangling for \"%s\"", tmp);
		      cplusplus_hint (saved_arg);
		      return_to_top_level ();
		    }
		  copy = (char*) alloca (3 + strlen(opname));
		  sprintf (copy, "__%s", opname);
		  p = q1;
		}
	      else
		{
		  copy = (char *) alloca (p - *argptr + 1 + (q1 - q));
		  memcpy (copy, *argptr, p - *argptr);
		  copy[p - *argptr] = '\0';
		}

	      /* no line number may be specified */
	      while (*p == ' ' || *p == '\t') p++;
	      *argptr = p;

	      sym = 0;
	      i1 = 0;		/*  counter for the symbol array */
	      t = SYMBOL_TYPE (sym_class);
	      sym_arr = (struct symbol **) alloca(TYPE_NFN_FIELDS_TOTAL (t) * sizeof(struct symbol*));
	      physnames = (char **) alloca (TYPE_NFN_FIELDS_TOTAL (t) * sizeof(char*));

	      if (destructor_name_p (copy, t))
		{
		  /* destructors are a special case.  */
		  struct fn_field *f = TYPE_FN_FIELDLIST1 (t, 0);
		  int len = TYPE_FN_FIELDLIST_LENGTH (t, 0) - 1;
		  char *phys_name = TYPE_FN_FIELD_PHYSNAME (f, len);
		  physnames[i1] = (char *)alloca (strlen (phys_name) + 1);
		  strcpy (physnames[i1], phys_name);
		  sym_arr[i1] =
		    lookup_symbol (phys_name, SYMBOL_BLOCK_VALUE (sym_class),
				   VAR_NAMESPACE, 0, (struct symtab **)NULL);
		  if (sym_arr[i1]) i1++;
		}
	      else
		i1 = find_methods (t, copy, physnames, sym_arr);
	      if (i1 == 1)
		{
		  /* There is exactly one field with that name.  */
		  sym = sym_arr[0];

		  if (sym && SYMBOL_CLASS (sym) == LOC_BLOCK)
		    {
		      /* Arg is the name of a function */
		      pc = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) + FUNCTION_START_OFFSET;
		      if (funfirstline)
			SKIP_PROLOGUE (pc);
		      values.sals = (struct symtab_and_line *)xmalloc (sizeof (struct symtab_and_line));
		      values.nelts = 1;
		      values.sals[0] = find_pc_line (pc, 0);
		      values.sals[0].pc = (values.sals[0].end && values.sals[0].pc != pc) ? values.sals[0].end : pc;
		    }
		  else
		    {
		      values.nelts = 0;
		    }
		  return values;
		}
	      if (i1 > 0)
		{
		  /* There is more than one field with that name
		     (overloaded).  Ask the user which one to use.  */
		  return decode_line_2 (sym_arr, i1, funfirstline);
		}
	      else
		{
		  char *tmp;

		  if (OPNAME_PREFIX_P (copy))
		    {
		      tmp = (char *)alloca (strlen (copy+3) + 9);
		      strcpy (tmp, "operator ");
		      strcat (tmp, copy+3);
		    }
		  else
		    tmp = copy;
		  if (tmp[0] == '~')
		    warning ("the class `%s' does not have destructor defined",
			     sym_class->name);
		  else
		    warning ("the class %s does not have any method named %s",
			     sym_class->name, tmp);
		  cplusplus_hint (saved_arg);
		  return_to_top_level ();
		}
	    }
	  else
	    {
	      /* The quotes are important if copy is empty.  */
	      warning ("can't find class, struct, or union named \"%s\"",
		       copy);
	      cplusplus_hint (saved_arg);
	      return_to_top_level ();
	    }
	}
      /*  end of C++  */


      /* Extract the file name.  */
      p1 = p;
      while (p != *argptr && p[-1] == ' ') --p;
      copy = (char *) alloca (p - *argptr + 1);
      memcpy (copy, *argptr, p - *argptr);
      copy[p - *argptr] = 0;

      /* Find that file's data.  */
      s = lookup_symtab (copy);
      if (s == 0)
	{
	  if (!have_full_symbols () && !have_partial_symbols ())
	    error (no_symtab_msg);
	  error ("No source file named %s.", copy);
	}

      /* Discard the file name from the arg.  */
      p = p1 + 1;
      while (*p == ' ' || *p == '\t') p++;
      *argptr = p;
    }

  /* S is specified file's symtab, or 0 if no file specified.
     arg no longer contains the file name.  */

  /* Check whether arg is all digits (and sign) */

  p = *argptr;
  if (*p == '-' || *p == '+') p++;
  while (*p >= '0' && *p <= '9')
    p++;

  if (p != *argptr && (*p == 0 || *p == ' ' || *p == '\t' || *p == ','))
    {
      /* We found a token consisting of all digits -- at least one digit.  */
      enum sign {none, plus, minus} sign = none;

      /* This is where we need to make sure that we have good defaults.
	 We must guarantee that this section of code is never executed
	 when we are called with just a function name, since
	 select_source_symtab calls us with such an argument  */

      if (s == 0 && default_symtab == 0)
	{
	  select_source_symtab (0);
	  default_symtab = current_source_symtab;
	  default_line = current_source_line;
	}

      if (**argptr == '+')
	sign = plus, (*argptr)++;
      else if (**argptr == '-')
	sign = minus, (*argptr)++;
      val.line = atoi (*argptr);
      switch (sign)
	{
	case plus:
	  if (p == *argptr)
	    val.line = 5;
	  if (s == 0)
	    val.line = default_line + val.line;
	  break;
	case minus:
	  if (p == *argptr)
	    val.line = 15;
	  if (s == 0)
	    val.line = default_line - val.line;
	  else
	    val.line = 1;
	  break;
	case none:
	  break;	/* No need to adjust val.line.  */
	}

      while (*p == ' ' || *p == '\t') p++;
      *argptr = p;
      if (s == 0)
	s = default_symtab;
      val.symtab = s;
      val.pc = 0;
      values.sals = (struct symtab_and_line *)xmalloc (sizeof (struct symtab_and_line));
      values.sals[0] = val;
      values.nelts = 1;
      return values;
    }

  /* Arg token is not digits => try it as a variable name
     Find the next token (everything up to end or next whitespace).  */

  p = skip_quoted (*argptr);
  copy = (char *) alloca (p - *argptr + 1);
  memcpy (copy, *argptr, p - *argptr);
  copy[p - *argptr] = '\0';
  if ((copy[0] == copy [p - *argptr - 1])
      && strchr (gdb_completer_quote_characters, copy[0]) != NULL)
    {
      char *temp;
      copy [p - *argptr - 1] = '\0';
      copy++;
      if ((temp = expensive_mangler (copy)) != NULL)
	{
	  copy = temp;
	}
    }
  while (*p == ' ' || *p == '\t') p++;
  *argptr = p;

  /* Look up that token as a variable.
     If file specified, use that file's per-file block to start with.  */

  sym = lookup_symbol (copy,
		       (s ? BLOCKVECTOR_BLOCK (BLOCKVECTOR (s), STATIC_BLOCK)
			: get_selected_block ()),
		       VAR_NAMESPACE, 0, &sym_symtab);

  if (sym != NULL)
    {
      if (SYMBOL_CLASS (sym) == LOC_BLOCK)
	{
	  /* Arg is the name of a function */
	  pc = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) + FUNCTION_START_OFFSET;
	  if (funfirstline)
	    SKIP_PROLOGUE (pc);
	  val = find_pc_line (pc, 0);
#ifdef PROLOGUE_FIRSTLINE_OVERLAP
	  /* Convex: no need to suppress code on first line, if any */
	  val.pc = pc;
#else
	  /* If SKIP_PROLOGUE left us in mid-line, and the next line is still
	     part of the same function:
		advance to next line, 
	        recalculate its line number (might not be N+1).  */
	  if (val.pc != pc && val.end &&
	      lookup_minimal_symbol_by_pc (pc) == lookup_minimal_symbol_by_pc (val.end)) {
	    pc = val.end;	/* First pc of next line */
	    val = find_pc_line (pc, 0);
	  }
	  val.pc = pc;
#endif
	  values.sals = (struct symtab_and_line *)xmalloc (sizeof (struct symtab_and_line));
	  values.sals[0] = val;
	  values.nelts = 1;
	  
	  /* I think this is always the same as the line that
	     we calculate above, but the general principle is
	     "trust the symbols more than stuff like
	     SKIP_PROLOGUE".  */
	  if (SYMBOL_LINE (sym) != 0)
	    values.sals[0].line = SYMBOL_LINE (sym);
	  
	  return values;
	}
      else if (SYMBOL_LINE (sym) != 0)
	{
	  /* We know its line number.  */
	  values.sals = (struct symtab_and_line *)
	    xmalloc (sizeof (struct symtab_and_line));
	  values.nelts = 1;
	  memset (&values.sals[0], 0, sizeof (values.sals[0]));
	  values.sals[0].symtab = sym_symtab;
	  values.sals[0].line = SYMBOL_LINE (sym);
	  return values;
	}
      else
	/* This can happen if it is compiled with a compiler which doesn't
	   put out line numbers for variables.  */
	error ("Line number not known for symbol \"%s\"", copy);
    }

  msymbol = lookup_minimal_symbol (copy, (struct objfile *) NULL);
  if (msymbol != NULL)
    {
      val.symtab = 0;
      val.line = 0;
      val.pc = msymbol -> address + FUNCTION_START_OFFSET;
      if (funfirstline)
	SKIP_PROLOGUE (val.pc);
      values.sals = (struct symtab_and_line *)xmalloc (sizeof (struct symtab_and_line));
      values.sals[0] = val;
      values.nelts = 1;
      return values;
    }

  if (!have_full_symbols () &&
      !have_partial_symbols () && !have_minimal_symbols ())
    error (no_symtab_msg);

  error ("Function \"%s\" not defined.", copy);
  return values;	/* for lint */
}

struct symtabs_and_lines
decode_line_spec (string, funfirstline)
     char *string;
     int funfirstline;
{
  struct symtabs_and_lines sals;
  if (string == 0)
    error ("Empty line specification.");
  sals = decode_line_1 (&string, funfirstline,
			current_source_symtab, current_source_line);
  if (*string)
    error ("Junk at end of line specification: %s", string);
  return sals;
}

/* Given a list of NELTS symbols in sym_arr (with corresponding
   mangled names in physnames), return a list of lines to operate on
   (ask user if necessary).  */
static struct symtabs_and_lines
decode_line_2 (sym_arr, nelts, funfirstline)
     struct symbol *sym_arr[];
     int nelts;
     int funfirstline;
{
  struct symtabs_and_lines values, return_values;
  register CORE_ADDR pc;
  char *args, *arg1;
  int i;
  char *prompt;
  char *demangled;

  values.sals = (struct symtab_and_line *) alloca (nelts * sizeof(struct symtab_and_line));
  return_values.sals = (struct symtab_and_line *) xmalloc (nelts * sizeof(struct symtab_and_line));

  i = 0;
  printf("[0] cancel\n[1] all\n");
  while (i < nelts)
    {
      if (sym_arr[i] && SYMBOL_CLASS (sym_arr[i]) == LOC_BLOCK)
	{
	  /* Arg is the name of a function */
	  pc = BLOCK_START (SYMBOL_BLOCK_VALUE (sym_arr[i])) 
	       + FUNCTION_START_OFFSET;
	  if (funfirstline)