Coding system support cleanup and minor refactoring.

* coding.h (enum coding_result_code): Remove
CODING_RESULT_INCONSISTENT_EOL and CODING_RESULT_INSUFFICIENT_MEM.
(toplevel): Remove unused CODING_MODE_INHIBIT_INCONSISTENT_EOL.
(CODING_MODE_LAST_BLOCK, CODING_MODE_SELECTIVE_DISPLAY)
(CODING_MODE_DIRECTION, CODING_MODE_FIXED_DESTINATION)
(CODING_MODE_SAFE_ENCODING): Rearrange bit values.
(decode_coding_region, encode_coding_region, decode_coding_string):
Remove unused compatibility macros.
* coding.c (Qinconsistent_eol, Qinsufficient_memory): Remove.
(record_conversion_result): Adjust user.
(syms_of_coding): Likewise.
(ALLOC_CONVERSION_WORK_AREA): Use SAFE_ALLOCA.
(decode_coding, encode_coding): Add USE_SAFE_ALLOCA and SAFE_FREE.
(decode_coding_object): Simplify since xrealloc never returns NULL.
Add eassert.

3 files changed, 37 insertions, 61 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index bbf2aae960a..00d78a83336 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,22 @@
+2013-03-06  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Coding system support cleanup and minor refactoring.
+        * coding.h (enum coding_result_code): Remove
+        CODING_RESULT_INCONSISTENT_EOL and CODING_RESULT_INSUFFICIENT_MEM.
+        (toplevel): Remove unused CODING_MODE_INHIBIT_INCONSISTENT_EOL.
+        (CODING_MODE_LAST_BLOCK, CODING_MODE_SELECTIVE_DISPLAY)
+        (CODING_MODE_DIRECTION, CODING_MODE_FIXED_DESTINATION)
+        (CODING_MODE_SAFE_ENCODING): Rearrange bit values.
+        (decode_coding_region, encode_coding_region, decode_coding_string):
+        Remove unused compatibility macros.
+        * coding.c (Qinconsistent_eol, Qinsufficient_memory): Remove.
+        (record_conversion_result): Adjust user.
+        (syms_of_coding): Likewise.
+        (ALLOC_CONVERSION_WORK_AREA): Use SAFE_ALLOCA.
+        (decode_coding, encode_coding): Add USE_SAFE_ALLOCA and SAFE_FREE.
+        (decode_coding_object): Simplify since xrealloc never returns NULL.
+        Add eassert.
+
 2013-03-06  Paul Eggert  <eggert@cs.ucla.edu>
 
         Fix a build failure on OpenBSD 4.x and MirBSD (Bug#13881).
diff --git a/src/coding.c b/src/coding.c
index 868fb7df0ea..32da72ab626 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -322,8 +322,7 @@ Lisp_Object Qcall_process, Qcall_process_region;
 Lisp_Object Qstart_process, Qopen_network_stream;
 static Lisp_Object Qtarget_idx;
 
-static Lisp_Object Qinsufficient_source, Qinconsistent_eol, Qinvalid_source;
-static Lisp_Object Qinterrupted, Qinsufficient_memory;
+static Lisp_Object Qinsufficient_source, Qinvalid_source, Qinterrupted;
 
 /* If a symbol has this property, evaluate the value to define the
    symbol as a coding system.  */
@@ -820,18 +819,12 @@ record_conversion_result (struct coding_system *coding,
     case CODING_RESULT_INSUFFICIENT_SRC:
       Vlast_code_conversion_error = Qinsufficient_source;
       break;
-    case CODING_RESULT_INCONSISTENT_EOL:
-      Vlast_code_conversion_error = Qinconsistent_eol;
-      break;
     case CODING_RESULT_INVALID_SRC:
       Vlast_code_conversion_error = Qinvalid_source;
       break;
     case CODING_RESULT_INTERRUPT:
       Vlast_code_conversion_error = Qinterrupted;
       break;
-    case CODING_RESULT_INSUFFICIENT_MEM:
-      Vlast_code_conversion_error = Qinsufficient_memory;
-      break;
     case CODING_RESULT_INSUFFICIENT_DST:
       /* Don't record this error in Vlast_code_conversion_error
          because it happens just temporarily and is resolved when the
@@ -6884,22 +6877,8 @@ produce_charset (struct coding_system *coding, int *charbuf, ptrdiff_t pos)
 
 #define ALLOC_CONVERSION_WORK_AREA(coding)                              \
   do {                                                                  \
-    int size = CHARBUF_SIZE;                                            \
-                                                                        \
-    coding->charbuf = NULL;                                             \
-    while (size > 1024)                                                 \
-      {                                                                 \
-        coding->charbuf = alloca (sizeof (int) * size);                 \
-        if (coding->charbuf)                                            \
-          break;                                                        \
-        size >>= 1;                                                     \
-      }                                                                 \
-    if (! coding->charbuf)                                              \
-      {                                                                 \
-        record_conversion_result (coding, CODING_RESULT_INSUFFICIENT_MEM); \
-        return;                                                         \
-      }                                                                 \
-    coding->charbuf_size = size;                                        \
+    coding->charbuf = SAFE_ALLOCA (CHARBUF_SIZE * sizeof (int));        \
+    coding->charbuf_size = CHARBUF_SIZE;                                \
   } while (0)
 
 
@@ -6968,6 +6947,8 @@ decode_coding (struct coding_system *coding)
   int carryover;
   int i;
 
+  USE_SAFE_ALLOCA;
+
   if (BUFFERP (coding->src_object)
       && coding->src_pos > 0
       && coding->src_pos < GPT
@@ -7090,6 +7071,8 @@ decode_coding (struct coding_system *coding)
       bset_undo_list (current_buffer, undo_list);
       record_insert (coding->dst_pos, coding->produced_char);
     }
+
+  SAFE_FREE ();
 }
 
 
@@ -7373,6 +7356,8 @@ encode_coding (struct coding_system *coding)
   int max_lookup;
   struct ccl_spec cclspec;
 
+  USE_SAFE_ALLOCA;
+
   attrs = CODING_ID_ATTRS (coding->id);
   if (coding->encoder == encode_coding_raw_text)
     translation_table = Qnil, max_lookup = 0;
@@ -7407,6 +7392,8 @@ encode_coding (struct coding_system *coding)
 
   if (BUFFERP (coding->dst_object) && coding->produced_char > 0)
     insert_from_gap (coding->produced_char, coding->produced);
+
+  SAFE_FREE ();
 }
 
 
@@ -7695,14 +7682,8 @@ decode_coding_object (struct coding_system *coding,
       set_buffer_internal (XBUFFER (coding->dst_object));
       if (dst_bytes < coding->produced)
         {
+          eassert (coding->produced > 0);
           destination = xrealloc (destination, coding->produced);
-          if (! destination)
-            {
-              record_conversion_result (coding,
-                                        CODING_RESULT_INSUFFICIENT_MEM);
-              unbind_to (count, Qnil);
-              return;
-            }
           if (BEGV < GPT && GPT < BEGV + coding->produced_char)
             move_gap_both (BEGV, BEGV_BYTE);
           memcpy (destination, BEGV_ADDR, coding->produced);
@@ -10408,10 +10389,8 @@ syms_of_coding (void)
         intern_c_string ("coding-category-undecided"));
 
   DEFSYM (Qinsufficient_source, "insufficient-source");
-  DEFSYM (Qinconsistent_eol, "inconsistent-eol");
   DEFSYM (Qinvalid_source, "invalid-source");
   DEFSYM (Qinterrupted, "interrupted");
-  DEFSYM (Qinsufficient_memory, "insufficient-memory");
   DEFSYM (Qcoding_system_define_form, "coding-system-define-form");
 
   defsubr (&Scoding_system_p);
diff --git a/src/coding.h b/src/coding.h
index eb95fa13ddb..28a7d776b63 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -272,37 +272,31 @@ enum coding_result_code
     CODING_RESULT_SUCCESS,
     CODING_RESULT_INSUFFICIENT_SRC,
     CODING_RESULT_INSUFFICIENT_DST,
-    CODING_RESULT_INCONSISTENT_EOL,
     CODING_RESULT_INVALID_SRC,
-    CODING_RESULT_INTERRUPT,
-    CODING_RESULT_INSUFFICIENT_MEM
+    CODING_RESULT_INTERRUPT
   };
 
 
 /* Macros used for the member `mode' of the struct coding_system.  */
 
-/* If set, recover the original CR or LF of the already decoded text
-   when the decoding routine encounters an inconsistent eol format.  */
-#define CODING_MODE_INHIBIT_INCONSISTENT_EOL    0x01
-
 /* If set, the decoding/encoding routines treat the current data as
    the last block of the whole text to be converted, and do the
    appropriate finishing job.  */
-#define CODING_MODE_LAST_BLOCK                  0x02
+#define CODING_MODE_LAST_BLOCK                  0x01
 
 /* If set, it means that the current source text is in a buffer which
    enables selective display.  */
-#define CODING_MODE_SELECTIVE_DISPLAY           0x04
+#define CODING_MODE_SELECTIVE_DISPLAY           0x02
 
 /* This flag is used by the decoding/encoding routines on the fly.  If
    set, it means that right-to-left text is being processed.  */
-#define CODING_MODE_DIRECTION                   0x08
+#define CODING_MODE_DIRECTION                   0x04
 
-#define CODING_MODE_FIXED_DESTINATION           0x10
+#define CODING_MODE_FIXED_DESTINATION           0x08
 
 /* If set, it means that the encoding routines produces some safe
    ASCII characters (usually '?') for unsupported characters.  */
-#define CODING_MODE_SAFE_ENCODING               0x20
+#define CODING_MODE_SAFE_ENCODING               0x10
 
   /* For handling composition sequence.  */
 #include "composite.h"
@@ -725,22 +719,6 @@ extern Lisp_Object from_unicode (Lisp_Object str);
 
 /* Macros for backward compatibility.  */
 
-#define decode_coding_region(coding, from, to)          \
-  decode_coding_object (coding, Fcurrent_buffer (),     \
-                        from, CHAR_TO_BYTE (from),      \
-                        to, CHAR_TO_BYTE (to), Fcurrent_buffer ())
-
-
-#define encode_coding_region(coding, from, to)          \
-  encode_coding_object (coding, Fcurrent_buffer (),     \
-                        from, CHAR_TO_BYTE (from),      \
-                        to, CHAR_TO_BYTE (to), Fcurrent_buffer ())
-
-
-#define decode_coding_string(coding, string, nocopy)                    \
-  decode_coding_object (coding, string, 0, 0, SCHARS (string),          \
-                        SBYTES (string), Qt)
-
 #define encode_coding_string(coding, string, nocopy)                    \
   (STRING_MULTIBYTE(string) ?                                           \
     (encode_coding_object (coding, string, 0, 0, SCHARS (string),       \