Re: [PATCH v2 16/18] Use generic_emit_char in Modula-2

[Gaius Mulley <gaiusmod2@gmail.com>]

Tom Tromey <tom@tromey.com> writes:

> This changes the Modula-2 code to use generic_emit_char and
> generic_printstr.  I have no way to test this.  However, the Modula-2
> code seems to be pretty much a copy of the old C code from before the
> charset work.
> ---
>  gdb/m2-lang.c | 144 +++++++++-----------------------------------------
>  gdb/m2-lang.h |   5 --
>  2 files changed, 26 insertions(+), 123 deletions(-)
>
> diff --git a/gdb/m2-lang.c b/gdb/m2-lang.c
> index 7673426b7a8..29aaec87405 100644
> --- a/gdb/m2-lang.c
> +++ b/gdb/m2-lang.c
> @@ -139,137 +139,45 @@ m2_language::language_arch_info (struct gdbarch *gdbarch,
>    lai->set_bool_type (builtin->builtin_bool, "BOOLEAN");
>  }
>  
> +/* A callback function for generic_emit_char and generic_printstr that
> +   escapes characters Modula 2-style.  */
> +
> +static void
> +m2_emit_char (obstack_wide_file *stream,
> +	      gdb_wint_t w,
> +	      gdb::array_view<const gdb_byte> orig,
> +	      int width,
> +	      enum bfd_endian byte_order,
> +	      int quoter,
> +	      bool *need_escapep)
> +{
> +  /* Historically the Modula-2 code in gdb handled \e as well.  */
> +  if (w == LCST ('\033'))
> +    fputs_filtered ("\\e", stream);
> +  else
> +    default_emit_wchar (stream, w, orig, width, byte_order, quoter,
> +			need_escapep);
> +}
> +
>  /* See languge.h.  */
>  
>  void
>  m2_language::printchar (int c, struct type *type,
>  			struct ui_file *stream) const
>  {
> -  fputs_filtered ("'", stream);
> -  emitchar (c, type, stream, '\'');
> -  fputs_filtered ("'", stream);
> +  generic_emit_char (c, type, stream, '\'', nullptr, m2_emit_char);
>  }
>  
>  /* See language.h.  */
>  
>  void
>  m2_language::printstr (struct ui_file *stream, struct type *elttype,
> -			const gdb_byte *string, unsigned int length,
> -			const char *encoding, int force_ellipses,
> -			const struct value_print_options *options) const
> -{
> -  unsigned int i;
> -  unsigned int things_printed = 0;
> -  int in_quotes = 0;
> -  int need_comma = 0;
> -
> -  if (length == 0)
> -    {
> -      puts_filtered ("\"\"");
> -      return;
> -    }
> -
> -  for (i = 0; i < length && things_printed < options->print_max; ++i)
> -    {
> -      /* Position of the character we are examining
> -	 to see whether it is repeated.  */
> -      unsigned int rep1;
> -      /* Number of repetitions we have detected so far.  */
> -      unsigned int reps;
> -
> -      QUIT;
> -
> -      if (need_comma)
> -	{
> -	  fputs_filtered (", ", stream);
> -	  need_comma = 0;
> -	}
> -
> -      rep1 = i + 1;
> -      reps = 1;
> -      while (rep1 < length && string[rep1] == string[i])
> -	{
> -	  ++rep1;
> -	  ++reps;
> -	}
> -
> -      if (reps > options->repeat_count_threshold)
> -	{
> -	  if (in_quotes)
> -	    {
> -	      fputs_filtered ("\", ", stream);
> -	      in_quotes = 0;
> -	    }
> -	  printchar (string[i], elttype, stream);
> -	  fprintf_filtered (stream, " <repeats %u times>", reps);
> -	  i = rep1 - 1;
> -	  things_printed += options->repeat_count_threshold;
> -	  need_comma = 1;
> -	}
> -      else
> -	{
> -	  if (!in_quotes)
> -	    {
> -	      fputs_filtered ("\"", stream);
> -	      in_quotes = 1;
> -	    }
> -	  emitchar (string[i], elttype, stream, '"');
> -	  ++things_printed;
> -	}
> -    }
> -
> -  /* Terminate the quotes if necessary.  */
> -  if (in_quotes)
> -    fputs_filtered ("\"", stream);
> -
> -  if (force_ellipses || i < length)
> -    fputs_filtered ("...", stream);
> -}
> -
> -/* See language.h.  */
> -
> -void
> -m2_language::emitchar (int ch, struct type *chtype,
> -		       struct ui_file *stream, int quoter) const
> +		       const gdb_byte *string, unsigned int length,
> +		       const char *encoding, int force_ellipses,
> +		       const struct value_print_options *options) const
>  {
> -  ch &= 0xFF;			/* Avoid sign bit follies.  */
> -
> -  if (PRINT_LITERAL_FORM (ch))
> -    {
> -      if (ch == '\\' || ch == quoter)
> -	fputs_filtered ("\\", stream);
> -      fprintf_filtered (stream, "%c", ch);
> -    }
> -  else
> -    {
> -      switch (ch)
> -	{
> -	case '\n':
> -	  fputs_filtered ("\\n", stream);
> -	  break;
> -	case '\b':
> -	  fputs_filtered ("\\b", stream);
> -	  break;
> -	case '\t':
> -	  fputs_filtered ("\\t", stream);
> -	  break;
> -	case '\f':
> -	  fputs_filtered ("\\f", stream);
> -	  break;
> -	case '\r':
> -	  fputs_filtered ("\\r", stream);
> -	  break;
> -	case '\033':
> -	  fputs_filtered ("\\e", stream);
> -	  break;
> -	case '\007':
> -	  fputs_filtered ("\\a", stream);
> -	  break;
> -	default:
> -	  fprintf_filtered (stream, "\\%.3o", (unsigned int) ch);
> -	  break;
> -	}
> -    }
> +  generic_printstr (stream, elttype, string, length, encoding, force_ellipses,
> +		    '"', 0, options, m2_emit_char);
>  }
>  
>  /* Called during architecture gdbarch initialisation to create language
> diff --git a/gdb/m2-lang.h b/gdb/m2-lang.h
> index ee2fc6fb8bc..2f516bc6427 100644
> --- a/gdb/m2-lang.h
> +++ b/gdb/m2-lang.h
> @@ -92,11 +92,6 @@ class m2_language : public language_defn
>  
>    /* See language.h.  */
>  
> -  void emitchar (int ch, struct type *chtype,
> -		 struct ui_file *stream, int quoter) const;
> -
> -  /* See language.h.  */
> -
>    void printchar (int ch, struct type *chtype,
>  		  struct ui_file *stream) const override;

Hi Tom,

all looks fine - but I'll test this and report back.  It might be a few
days as my Internet connection is down - storm damage on the North
Cornwall coast,

regards,
Gaius