re PR sanitizer/55617 (static constructors are not being instrumented correctly on darwin)

2013-02-04  Alexander Potapenko <glider@google.com>
            Jack Howarth  <howarth@bromo.med.uc.edu>
	        Jakub Jelinek  <jakub@redhat.com>

		PR sanitizer/55617
		* config/darwin.c (sort_ctor_records): Stabilized qsort
		on constructor priority by using original position.
		(finalize_ctors): New routine to sort constructors by
		priority before use in assemble_integer.
		(machopic_asm_out_constructor): Use finalize_ctors if needed.

Co-Authored-By: Jack Howarth <howarth@bromo.med.uc.edu>
Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r195735

2 files changed, 58 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cc67ff9..bfb857d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2013-02-04  Alexander Potapenko <glider@google.com>
+            Jack Howarth  <howarth@bromo.med.uc.edu>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/55617
+	* config/darwin.c (sort_ctor_records): Stabilized qsort
+	on constructor priority by using original position.
+	(finalize_ctors): New routine to sort constructors by
+	priority before use in assemble_integer.
+	(machopic_asm_out_constructor): Use finalize_ctors if needed.
+
 2013-02-04  Jakub Jelinek  <jakub@redhat.com>
 
 	PR libstdc++/54314
diff --git a/gcc/config/darwin.c b/gcc/config/darwin.c
index 0c79139..f1bf24a 100644
--- a/gcc/config/darwin.c
+++ b/gcc/config/darwin.c
@@ -83,6 +83,14 @@ along with GCC; see the file COPYING3.  If not see
    kernel) the stubs might still be required, and this will be set true.  */
 int darwin_emit_branch_islands = false;
 
+typedef struct GTY(()) ctor_record {
+  rtx symbol;
+  int priority;		/* constructor priority */
+  int position;		/* original position */
+} ctor_record;
+
+static GTY(()) vec<ctor_record, va_gc> *ctors = NULL;
+
 /* A flag to determine whether we are running c++ or obj-c++.  This has to be
    settable from non-c-family contexts too (i.e. we can't use the c_dialect_
    functions).  */
@@ -1708,15 +1716,48 @@ machopic_select_rtx_section (enum machine_mode mode, rtx x,
 void
 machopic_asm_out_constructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
 {
+  ctor_record new_elt = {symbol, priority, vec_safe_length (ctors)};
+
+  vec_safe_push (ctors, new_elt);
+
+  if (! MACHOPIC_INDIRECT)
+    fprintf (asm_out_file, ".reference .constructors_used\n");
+}
+
+static int
+sort_ctor_records (const void * a, const void * b)
+{
+  const ctor_record *ca = (const ctor_record *)a;
+  const ctor_record *cb = (const ctor_record *)b;
+  if (ca->priority > cb->priority)
+    return 1;
+  if (ca->priority < cb->priority)
+    return -1;
+  if (ca->position > cb->position)
+    return 1;
+  if (ca->position < cb->position)
+    return -1;
+  return 0;
+}
+
+static void 
+finalize_ctors()
+{
+  unsigned int i;
+  ctor_record *elt;
+ 
   if (MACHOPIC_INDIRECT)
     switch_to_section (darwin_sections[mod_init_section]);
   else
     switch_to_section (darwin_sections[constructor_section]);
-  assemble_align (POINTER_SIZE);
-  assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
 
-  if (! MACHOPIC_INDIRECT)
-    fprintf (asm_out_file, ".reference .constructors_used\n");
+  if (vec_safe_length (ctors) > 1)
+    ctors->qsort (sort_ctor_records);
+  FOR_EACH_VEC_SAFE_ELT (ctors, i, elt)
+    {
+      assemble_align (POINTER_SIZE);
+      assemble_integer (elt->symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
+    }
 }
 
 void
@@ -2762,6 +2803,8 @@ darwin_file_start (void)
 void
 darwin_file_end (void)
 {
+  if (!vec_safe_is_empty (ctors))
+    finalize_ctors();
   machopic_finish (asm_out_file);
   if (strcmp (lang_hooks.name, "GNU C++") == 0)
     {