Problem report #113: base/src/emacs/src/coding.c (decode_coding_object); UNINIT

Problem report #113: base/src/emacs/src/coding.c (decode_coding_object); UNINIT

[Dan Nicolaescu]

CID: 113
Checker: UNINIT (help)
File: base/src/emacs/src/coding.c
Function: decode_coding_object
Description: Using uninitialized value "saved_pt_byte" in call to function "temp_set_point_both"

Event var_decl: Declared variable "saved_pt_byte" without initializer
Also see events: [uninit_use][uninit_use][uninit_use_in_call]

7141 	  int saved_pt = -1, saved_pt_byte;
7142 	  int need_marker_adjustment = 0;
7143 	  Lisp_Object old_deactivate_mark;
7144 	
7145 	  old_deactivate_mark = Vdeactivate_mark;
7146 	

At conditional (1): "dst_object == Qnil" taking true path

7147 	  if (NILP (dst_object))
7148 	    {
7149 	      destination = coding->destination;
7150 	      dst_bytes = coding->dst_bytes;
7151 	    }
7152 	
7153 	  coding->src_object = src_object;
7154 	  coding->src_chars = chars;
7155 	  coding->src_bytes = bytes;

At conditional (2): "chars < bytes" taking true path

7156 	  coding->src_multibyte = chars < bytes;
7157 	

At conditional (3): "src_object & 7 == 3" taking false path

7158 	  if (STRINGP (src_object))
7159 	    {
7160 	      coding->src_pos = from;
7161 	      coding->src_pos_byte = from_byte;
7162 	    }

At conditional (4): "src_object & 7 == 4" taking true path
At conditional (5): "((0), (src_object & -8))->size & 4611686018427518976 == 4611686018427518976" taking true path

7163 	  else if (BUFFERP (src_object))
7164 	    {
7165 	      set_buffer_internal (XBUFFER (src_object));

At conditional (6): "from != ((current_buffer)->text)->gpt" taking true path

7166 	      if (from != GPT)
7167 		move_gap_both (from, from_byte);

At conditional (7): "src_object == dst_object" taking false path

7168 	      if (EQ (src_object, dst_object))
7169 		{
7170 		  struct Lisp_Marker *tail;
7171 	
7172 		  for (tail = BUF_MARKERS (current_buffer); tail; tail = tail->next)
7173 		    {
7174 		      tail->need_adjustment
7175 			= tail->charpos == (tail->insertion_type ? from : to);
7176 		      need_marker_adjustment |= tail->need_adjustment;
7177 		    }
7178 		  saved_pt = PT, saved_pt_byte = PT_BYTE;
7179 		  TEMP_SET_PT_BOTH (from, from_byte);
7180 		  current_buffer->text->inhibit_shrinking = 1;
7181 		  del_range_both (from, from_byte, to, to_byte, 1);
7182 		  coding->src_pos = -chars;
7183 		  coding->src_pos_byte = -bytes;
7184 		}
7185 	      else
7186 		{
7187 		  coding->src_pos = from;
7188 		  coding->src_pos_byte = from_byte;
7189 		}
7190 	    }
7191 	

At conditional (8): "(coding)->common_flags & 4096 != 0" taking true path

7192 	  if (CODING_REQUIRE_DETECTION (coding))
7193 	    detect_coding (coding);
7194 	  attrs = CODING_ID_ATTRS (coding->id);
7195 	

At conditional (9): "dst_object == Qt" taking true path

7196 	  if (EQ (dst_object, Qt)
7197 	      || (! NILP (CODING_ATTR_POST_READ (attrs))
7198 		  && NILP (dst_object)))
7199 	    {

At conditional (10): "(coding)->common_flags & 256 == 0" taking true path

7200 	      coding->dst_multibyte = !CODING_FOR_UNIBYTE (coding);
7201 	      coding->dst_object = code_conversion_save (1, coding->dst_multibyte);
7202 	      coding->dst_pos = BEG;
7203 	      coding->dst_pos_byte = BEG_BYTE;
7204 	    }
7205 	  else if (BUFFERP (dst_object))
7206 	    {
7207 	      code_conversion_save (0, 0);
7208 	      coding->dst_object = dst_object;
7209 	      coding->dst_pos = BUF_PT (XBUFFER (dst_object));
7210 	      coding->dst_pos_byte = BUF_PT_BYTE (XBUFFER (dst_object));
7211 	      coding->dst_multibyte
7212 		= ! NILP (XBUFFER (dst_object)->enable_multibyte_characters);
7213 	    }
7214 	  else
7215 	    {
7216 	      code_conversion_save (0, 0);
7217 	      coding->dst_object = Qnil;
7218 	      /* Most callers presume this will return a multibyte result, and they
7219 		 won't use `binary' or `raw-text' anyway, so let's not worry about
7220 		 CODING_FOR_UNIBYTE.  */
7221 	      coding->dst_multibyte = 1;
7222 	    }
7223 	
7224 	  decode_coding (coding);
7225 	

At conditional (11): "(coding)->dst_object & 7 == 4" taking true path
At conditional (12): "((0), ((coding)->dst_object & -8))->size & 4611686018427518976 == 4611686018427518976" taking true path

7226 	  if (BUFFERP (coding->dst_object))
7227 	    set_buffer_internal (XBUFFER (coding->dst_object));
7228 	

At conditional (13): "((0), (attrs & -8))->contents[9] != Qnil" taking true path

7229 	  if (! NILP (CODING_ATTR_POST_READ (attrs)))
7230 	    {
7231 	      struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
7232 	      EMACS_INT prev_Z = Z, prev_Z_BYTE = Z_BYTE;
7233 	      Lisp_Object val;
7234 	
7235 	      TEMP_SET_PT_BOTH (coding->dst_pos, coding->dst_pos_byte);
7236 	      GCPRO5 (coding->src_object, coding->dst_object, src_object, dst_object,
7237 		      old_deactivate_mark);
7238 	      val = safe_call1 (CODING_ATTR_POST_READ (attrs),
7239 				make_number (coding->produced_char));
7240 	      UNGCPRO;

At conditional (14): "val & 7 != 0" taking false path
At conditional (15): "val >> 3 < 0" taking false path
At conditional (16): "0" taking false path

7241 	      CHECK_NATNUM (val);
7242 	      coding->produced_char += Z - prev_Z;
7243 	      coding->produced += Z_BYTE - prev_Z_BYTE;
7244 	    }
7245 	

At conditional (17): "dst_object == Qt" taking true path

7246 	  if (EQ (dst_object, Qt))
7247 	    {
7248 	      coding->dst_object = Fbuffer_string ();
7249 	    }
7250 	  else if (NILP (dst_object) && BUFFERP (coding->dst_object))
7251 	    {
7252 	      set_buffer_internal (XBUFFER (coding->dst_object));
7253 	      if (dst_bytes < coding->produced)
7254 		{
7255 		  destination = xrealloc (destination, coding->produced);
7256 		  if (! destination)
7257 		    {
7258 		      record_conversion_result (coding,
7259 						CODING_RESULT_INSUFFICIENT_DST);
7260 		      unbind_to (count, Qnil);
7261 		      return;
7262 		    }
7263 		  if (BEGV < GPT && GPT < BEGV + coding->produced_char)
7264 		    move_gap_both (BEGV, BEGV_BYTE);
7265 		  bcopy (BEGV_ADDR, destination, coding->produced);
7266 		  coding->destination = destination;
7267 		}
7268 	    }
7269 	

At conditional (18): "saved_pt >= 0" taking true path

7270 	  if (saved_pt >= 0)
7271 	    {
7272 	      /* This is the case of:
7273 		 (BUFFERP (src_object) && EQ (src_object, dst_object))
7274 		 As we have moved PT while replacing the original buffer
7275 		 contents, we must recover it now.  */
7276 	      set_buffer_internal (XBUFFER (src_object));
7277 	      current_buffer->text->inhibit_shrinking = 0;

At conditional (19): "saved_pt < from" taking false path

7278 	      if (saved_pt < from)

Event uninit_use_in_call: Using uninitialized value "saved_pt_byte" in call to function "temp_set_point_both" [model]
Also see events: [var_decl][uninit_use][uninit_use]

7279 		TEMP_SET_PT_BOTH (saved_pt, saved_pt_byte);

At conditional (20): "saved_pt < (from + chars)" taking false path

7280 	      else if (saved_pt < from + chars)
7281 		TEMP_SET_PT_BOTH (from, from_byte);

At conditional (21): "(current_buffer)->enable_multibyte_characters != Qnil" taking true path

7282 	      else if (! NILP (current_buffer->enable_multibyte_characters))

Event uninit_use: Using uninitialized value "saved_pt_byte"
Also see events: [var_decl][uninit_use][uninit_use_in_call]

7283 		TEMP_SET_PT_BOTH (saved_pt + (coding->produced_char - chars),
7284 				  saved_pt_byte + (coding->produced - bytes));
7285 	      else

Event uninit_use: Using uninitialized value "saved_pt_byte"
Also see events: [var_decl][uninit_use][uninit_use_in_call]

7286 		TEMP_SET_PT_BOTH (saved_pt + (coding->produced - bytes),
7287 				  saved_pt_byte + (coding->produced - bytes));
7288 	
7289 	      if (need_marker_adjustment)

Re: Problem report #113: base/src/emacs/src/coding.c (decode_coding_object); UNINIT

[Davis Herring]

> 7141 	  int saved_pt = -1, saved_pt_byte;
[...]
> 7178 		  saved_pt = PT, saved_pt_byte = PT_BYTE;
[...]
> At conditional (18): "saved_pt >= 0" taking true path
>
> 7270 	  if (saved_pt >= 0)
[...]
> Event uninit_use_in_call: Using uninitialized value "saved_pt_byte" in
> call to function "temp_set_point_both" [model]
> Also see events: [var_decl][uninit_use][uninit_use]
>
> 7279 		TEMP_SET_PT_BOTH (saved_pt, saved_pt_byte);

No bug: saved_pt starts negative and is assigned iff saved_pt_byte is.

Davis

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