[PATCH] gcc: Add deleted assignment operators to non-copyable types

[Jonathan Wakely <jwakely@redhat.com>]

Bootstrapped and regtested on powerpc64le-linux.

OK for trunk?

It's safe to do now rather than waiting for Stage 1, because if we were
actually relying on copy-assigning these types it would have failed to
compile with this change. So it has no functional change, but will help
prevent any future misuse of these types.

-- >8 --

The auto_timevar and auto_cond_timevar classes are supposed to be
non-copyable, but they have implicit assignment operators. Define their
assignment operators as deleted.

The auto_bitmap declares private copy/move constructors/assignments,
which can be replced with deleted copies to get the same effect but
using more idiomatic C++11 style.

gcc/ChangeLog:

	* bitmap.h (class auto_bitmap): Replace private-and-undefined
	copy and move special member functions with deleted copies.
	* timevar.h (class auto_timevar): Delete assignment operator.
	(class auto_cond_timevar): Likewise.
---
 gcc/bitmap.h  | 11 ++++-------
 gcc/timevar.h |  6 ++++--
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/gcc/bitmap.h b/gcc/bitmap.h
index 43337d2e9d9..ccb484651ab 100644
--- a/gcc/bitmap.h
+++ b/gcc/bitmap.h
@@ -945,7 +945,7 @@ bmp_iter_and_compl (bitmap_iterator *bi, unsigned *bit_no)
 /* A class that ties the lifetime of a bitmap to its scope.  */
 class auto_bitmap
 {
- public:
+public:
   auto_bitmap (ALONE_CXX_MEM_STAT_INFO)
     { bitmap_initialize (&m_bits, &bitmap_default_obstack PASS_MEM_STAT); }
   explicit auto_bitmap (bitmap_obstack *o CXX_MEM_STAT_INFO)
@@ -954,12 +954,9 @@ class auto_bitmap
   // Allow calling bitmap functions on our bitmap.
   operator bitmap () { return &m_bits; }
 
- private:
-  // Prevent making a copy that references our bitmap.
-  auto_bitmap (const auto_bitmap &);
-  auto_bitmap &operator = (const auto_bitmap &);
-  auto_bitmap (auto_bitmap &&);
-  auto_bitmap &operator = (auto_bitmap &&);
+  // Prevent shallow copies.
+  auto_bitmap (const auto_bitmap &) = delete;
+  auto_bitmap &operator = (const auto_bitmap &) = delete;
 
   bitmap_head m_bits;
 };
diff --git a/gcc/timevar.h b/gcc/timevar.h
index ad465731609..b2d13d44190 100644
--- a/gcc/timevar.h
+++ b/gcc/timevar.h
@@ -247,8 +247,9 @@ class auto_timevar
       m_timer->pop (m_tv);
   }
 
-  // Disallow copies.
+  // Prevent shallow copies.
   auto_timevar (const auto_timevar &) = delete;
+  auto_timevar &operator= (const auto_timevar &) = delete;
 
  private:
   timer *m_timer;
@@ -279,8 +280,9 @@ class auto_cond_timevar
       m_timer->cond_stop (m_tv);
   }
 
-  // Disallow copies.
+  // Prevent shallow copies.
   auto_cond_timevar (const auto_cond_timevar &) = delete;
+  auto_cond_timevar &operator= (const auto_cond_timevar &) = delete;
 
  private:
   void start()
-- 
2.39.2