gas line buffer handling

This fixes a segfault when macro definitions end on the last line of a
file, and that line isn't properly terminated with a newline.  gas
used to throw away the last line in cases like this, whereas in other
cases gas added the missing newline.  So I've also made gas
consistently provide a missing newline.

	PR gas/18687
	* input-scrub.c (input_scrub_next_buffer): Rearrange and simplify
	loop.  Don't drop lines at end of file lacking a newline, add a
	newline instead.  Ensure partial_size is zero whenever
	partial_where is NULL.  Adjust buffer size for extra char.
	(input_scrub_push, input_scrub_begin): Adjust buffer size here too.

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 5ea971497840f7a4b93459620a4c6d68feae8b6d..a3268cb95d4f3183c513774c4dfb0ed4b7019f78 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,12 @@
+2015-07-22  Alan Modra  <amodra@gmail.com>
+
+       PR gas/18687
+       * input-scrub.c (input_scrub_next_buffer): Rearrange and simplify
+       loop.  Don't drop lines at end of file lacking a newline, add a
+       newline instead.  Ensure partial_size is zero whenever
+       partial_where is NULL.  Adjust buffer size for extra char.
+       (input_scrub_push, input_scrub_begin): Adjust buffer size here too.
+
 2015-07-20  Matthew Wahab  <matthew.wahab@arm.com>
 
        * NEWS: Mention corrected spelling of armv6kz.

diff --git a/gas/input-scrub.c b/gas/input-scrub.c
index b94f4e47eab6b116b14b23b0d7f4c66e73c6b34a..c8e1e29c7ff7227f53b0748e9cfb13adb22adeb4 100644 (file)
--- a/gas/input-scrub.c
+++ b/gas/input-scrub.c
@@ -164,7 +164,7 @@ input_scrub_push (char *saved_position)
   sb_index = -1;
 
   buffer_start = (char *) xmalloc ((BEFORE_SIZE + buffer_length
-                                    + buffer_length + AFTER_SIZE));
+                                    + buffer_length + AFTER_SIZE + 1));
   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 
   return saved;
@@ -209,7 +209,7 @@ input_scrub_begin (void)
   buffer_length = input_file_buffer_size ();
 
   buffer_start = (char *) xmalloc ((BEFORE_SIZE + buffer_length
-                                    + buffer_length + AFTER_SIZE));
+                                    + buffer_length + AFTER_SIZE + 1));
   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 
   /* Line number things.  */
@@ -329,6 +329,7 @@ input_scrub_next_buffer (char **bufp)
            }
          --macro_nest;
          partial_where = NULL;
+         partial_size = 0;
          if (next_saved_file != NULL)
            *bufp = input_scrub_pop (next_saved_file);
          return partial_where;
@@ -341,79 +342,68 @@ input_scrub_next_buffer (char **bufp)
       return partial_where;
     }
 
-  *bufp = buffer_start + BEFORE_SIZE;
-
   if (partial_size)
     {
       memmove (buffer_start + BEFORE_SIZE, partial_where,
               (unsigned int) partial_size);
       memcpy (buffer_start + BEFORE_SIZE, save_source, AFTER_SIZE);
     }
-  limit = input_file_give_next_buffer (buffer_start
-                                      + BEFORE_SIZE
-                                      + partial_size);
-  if (limit)
+
+  while (1)
     {
-      char *p;         /* Find last newline.  */
-      /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN.  */
-      *limit = '\0';
-      for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
-       ;
-      ++p;
-
-      while (p <= buffer_start + BEFORE_SIZE)
+      char *p;
+
+      *bufp = buffer_start + BEFORE_SIZE;
+      limit = input_file_give_next_buffer (buffer_start
+                                          + BEFORE_SIZE
+                                          + partial_size);
+      if (!limit)
        {
-         int limoff;
-
-         limoff = limit - buffer_start;
-         buffer_length += input_file_buffer_size ();
-         buffer_start = (char *) xrealloc (buffer_start,
-                                            (BEFORE_SIZE
-                                             + 2 * buffer_length
-                                             + AFTER_SIZE));
-         *bufp = buffer_start + BEFORE_SIZE;
-         limit = input_file_give_next_buffer (buffer_start + limoff);
-
-         if (limit == NULL)
-           {
-             as_warn (_("partial line at end of file ignored"));
-             partial_where = NULL;
-             if (next_saved_file)
-               *bufp = input_scrub_pop (next_saved_file);
-             return NULL;
-           }
+         if (partial_size == 0)
+           break;
 
+         as_warn (_("end of file not at end of a line; newline inserted"));
+         p = buffer_start + BEFORE_SIZE + partial_size;
+         *p++ = '\n';
+         limit = p;
+       }
+      else
+       {
          /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN.  */
          *limit = '\0';
+
+         /* Find last newline.  */
          for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
            ;
          ++p;
        }
 
-      partial_where = p;
-      partial_size = limit - p;
-      memcpy (save_source, partial_where, (int) AFTER_SIZE);
-      memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
-    }
-  else
-    {
-      partial_where = 0;
-      if (partial_size > 0)
+      if (p != buffer_start + BEFORE_SIZE)
        {
-         as_warn (_("partial line at end of file ignored"));
+         partial_where = p;
+         partial_size = limit - p;
+         memcpy (save_source, partial_where, (int) AFTER_SIZE);
+         memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
+         return partial_where;
        }
 
-      /* Tell the listing we've finished the file.  */
-      LISTING_EOF ();
-
-      /* If we should pop to another file at EOF, do it.  */
-      if (next_saved_file)
-       {
-         *bufp = input_scrub_pop (next_saved_file);    /* Pop state */
-         /* partial_where is now correct to return, since we popped it.  */
-       }
+      partial_size = limit - (buffer_start + BEFORE_SIZE);
+      buffer_length += input_file_buffer_size ();
+      buffer_start = (char *) xrealloc (buffer_start,
+                                       (BEFORE_SIZE
+                                        + 2 * buffer_length
+                                        + AFTER_SIZE + 1));
     }
-  return (partial_where);
+
+  /* Tell the listing we've finished the file.  */
+  LISTING_EOF ();
+
+  /* If we should pop to another file at EOF, do it.  */
+  partial_where = NULL;
+  if (next_saved_file)
+    *bufp = input_scrub_pop (next_saved_file);
+
+  return partial_where;
 }
 \f
 /* The remaining part of this file deals with line numbers, error