gold patch committed: Fix descriptor handling

[Ian Lance Taylor <iant at google dot com>]

I managed to mess up the simple-minded stack of open file descriptors in
gold.  I committed this patch to make it slightly less simple-minded.

Ian


2009-02-27  Ian Lance Taylor  <iant@google.com>

	PR 5990
	* descriptors.h (Open_descriptor): Add is_on_stack field.
	* descriptors.cc (Descriptors::open): If the descriptor is on the
	top of the stack, remove it.  Initialize is_on_stack field.
	(Descriptors::release): Only add pod to stack if it is not on the
	stack already.
	(Descriptors::close_some_descriptor): Clear stack_next and
	is_on_stack fields.


Index: descriptors.cc
===================================================================
RCS file: /cvs/src/src/gold/descriptors.cc,v
retrieving revision 1.3
diff -p -u -r1.3 descriptors.cc
--- descriptors.cc	15 Jan 2009 01:29:25 -0000	1.3
+++ descriptors.cc	28 Feb 2009 03:01:33 -0000
@@ -75,6 +75,12 @@ Descriptors::open(int descriptor, const 
 	{
 	  gold_assert(!pod->inuse);
 	  pod->inuse = true;
+	  if (descriptor == this->stack_top_)
+	    {
+	      this->stack_top_ = pod->stack_next;
+	      pod->stack_next = -1;
+	      pod->is_on_stack = false;
+	    }
 	  return descriptor;
 	}
     }
@@ -114,6 +120,7 @@ Descriptors::open(int descriptor, const 
 	  pod->stack_next = -1;
 	  pod->inuse = true;
 	  pod->is_write = (flags & O_ACCMODE) != O_RDONLY;
+	  pod->is_on_stack = false;
 
 	  ++this->current_;
 	  if (this->current_ >= this->limit_)
@@ -158,10 +165,11 @@ Descriptors::release(int descriptor, boo
   else
     {
       pod->inuse = false;
-      if (!pod->is_write)
+      if (!pod->is_write && !pod->is_on_stack)
 	{
 	  pod->stack_next = this->stack_top_;
 	  this->stack_top_ = descriptor;
+	  pod->is_on_stack = true;
 	}
     }
 }
@@ -193,6 +201,8 @@ Descriptors::close_some_descriptor()
 	    this->stack_top_ = pod->stack_next;
 	  else
 	    this->open_descriptors_[last].stack_next = pod->stack_next;
+	  pod->stack_next = -1;
+	  pod->is_on_stack = false;
 	  return true;
 	}
       last = i;
Index: descriptors.h
===================================================================
RCS file: /cvs/src/src/gold/descriptors.h,v
retrieving revision 1.3
diff -p -u -r1.3 descriptors.h
--- descriptors.h	15 Jan 2009 01:29:25 -0000	1.3
+++ descriptors.h	28 Feb 2009 03:01:33 -0000
@@ -69,6 +69,8 @@ class Descriptors
     bool inuse;
     // Whether this is a write descriptor.
     bool is_write;
+    // Whether the descriptor is on the stack.
+    bool is_on_stack;
   };
 
   bool