This is the mail archive of the binutils@sourceware.org mailing list for the binutils project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[PATCH] Fix DEMANGLE_COMPONENT_TEMPLATE_ARGLIST demangling (PR other/43838)


Hi!

The dpi->len -= 2; trick to revert d_append_string (dpi, ", ");
is too fragile, as can be seen on the testcase below.
There are 2 problems:
1) the buffer can be flushed in the d_append_string (dpi, ", ");
   call.  If the recursive call doesn't print anything, it can't
   undo the ", " char addition - dpi->len will go negative.
2) if a flush (or more) happens during the recursive d_print_comp call
   then dpi->len might be equal to the saved len, but some characters
   were actually printed (if it is a multiple of 255 chars).
   By decrementing dpi->len then we eat two last characters, which
   won't be ", ".

1) is fixed by flushing before the d_append_string call if the buffer
is almost full.
2) is fixed by adding a counter how many flushes happened and comparing
   that to a saved value in addition to len.

Ok for trunk/4.5/4.4?

2010-06-09  Jakub Jelinek  <jakub@redhat.com>

	PR other/43838
	* cp-demangle.c (struct d_print_info): Add flush_count field.
	(d_print_init): Initialize it to 0.
	(d_print_flush): Increment it.
	(d_print_comp): If needed flush before appending ", ".  Only
	decrement dpi->len if no flushes happened during the recursive
	call.
	* testsuite/demangle-expected: Add a test for this.

--- libiberty/cp-demangle.c.jj	2010-05-07 09:17:47.000000000 +0200
+++ libiberty/cp-demangle.c	2010-06-09 20:19:56.000000000 +0200
@@ -302,6 +302,8 @@ struct d_print_info
   /* The current index into any template argument packs we are using
      for printing.  */
   int pack_index;
+  /* Number of d_print_flush calls so far.  */
+  unsigned long int flush_count;
 };
 
 #ifdef CP_DEMANGLE_DEBUG
@@ -3285,6 +3287,7 @@ d_print_init (struct d_print_info *dpi, 
   dpi->last_char = '\0';
   dpi->templates = NULL;
   dpi->modifiers = NULL;
+  dpi->flush_count = 0;
 
   dpi->callback = callback;
   dpi->opaque = opaque;
@@ -3314,6 +3317,7 @@ d_print_flush (struct d_print_info *dpi)
   dpi->buf[dpi->len] = '\0';
   dpi->callback (dpi->buf, dpi->len, dpi->opaque);
   dpi->len = 0;
+  dpi->flush_count++;
 }
 
 /* Append characters and buffers for printing.  */
@@ -4047,12 +4051,18 @@ d_print_comp (struct d_print_info *dpi,
       if (d_right (dc) != NULL)
 	{
 	  size_t len;
+	  unsigned long int flush_count;
+	  /* Make sure ", " isn't flushed by d_append_string, otherwise
+	     dpi->len -= 2 wouldn't work.  */
+	  if (dpi->len >= sizeof (dpi->buf) - 2)
+	    d_print_flush (dpi);
 	  d_append_string (dpi, ", ");
 	  len = dpi->len;
+	  flush_count = dpi->flush_count;
 	  d_print_comp (dpi, d_right (dc));
 	  /* If that didn't print anything (which can happen with empty
 	     template argument packs), remove the comma and space.  */
-	  if (dpi->len == len)
+	  if (dpi->flush_count == flush_count && dpi->len == len)
 	    dpi->len -= 2;
 	}
       return;
--- libiberty/testsuite/demangle-expected.jj	2010-05-28 14:36:06.000000000 +0200
+++ libiberty/testsuite/demangle-expected	2010-06-09 20:36:34.000000000 +0200
@@ -3951,6 +3951,9 @@ decltype (({parm#1}.(operator-))()) h<A>
 --format=gnu-v3
 _Z1fDn
 f(decltype(nullptr))
+--format=gnu-v3
+_ZN5aaaaa6bbbbbb5cccccIN23ddddddddddddddddddddddd3eeeENS2_4ffff16ggggggggggggggggENS0_9hhhhhhhhhES6_S6_S6_S6_S6_S6_S6_EE
+aaaaa::bbbbbb::ccccc<ddddddddddddddddddddddd::eee, ddddddddddddddddddddddd::ffff::gggggggggggggggg, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh>
 #
 # Ada (GNAT) tests.
 #

	Jakub


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]