[binutils-gdb] Fix clang/libc++ build

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=3046d67a0e29686ec18abd719660969c97973063

commit 3046d67a0e29686ec18abd719660969c97973063
Author: Pedro Alves <palves@redhat.com>
Date:   Thu Jan 24 18:01:49 2019 +0000

    Fix clang/libc++ build
    
    This fixes the following build error with clang/libc++, reported at
    <https://sourceware.org/ml/gdb-patches/2019-01/msg00537.html>:
    
      (...)
      In file included from breakpoint.c:34:
      In file included from ./inferior.h:54:
      ./common/forward-scope-exit.h:98:7: error: no matching constructor for
      initialization of 'decltype(std::bind(&delete_longjmp_breakpoint,
      std::declval<int>()))' (aka '__bind<void (*)(int), int>')
          : m_bind_function (std::bind (function, args...))
    	^                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      ./common/gdb_optional.h:155:19: note: in instantiation of member
      function 'detail::forward_scope_exit<void (int),
      &delete_longjmp_breakpoint, void (int)>::forward_scope_exit' requested
      here
          new (&m_item) T (std::forward<Args>(args)...);
    		    ^
      breakpoint.c:11127:18: note: in instantiation of function template
      specialization 'gdb::optional<detail::forward_scope_exit<void (int),
      &delete_longjmp_breakpoint, void (int)> >::emplace<int &>' requested
      here
    	lj_deleter.emplace (thread);
    		   ^
      /Applications/Xcode-10.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/functional:2220:7:
      note: candidate constructor (the implicit copy constructor) not
      viable: no known conversion from '__bind<[...], int &>' to 'const
      __bind<[...], int>' for 1st argument
      class __bind
    	^
      (...)
    
    I don't really know why I ended up with a copy here.  We can just pass
    the arguments directly to the being-constructed bind.
    
    gdb/ChangeLog:
    2019-01-24  Pedro Alves  <palves@redhat.com>
    
    	* common/forward-scope-exit.h
    	(forward_scope_exit::forward_scope_exit): Pass arguments to
    	m_bind_function directly, instead of creating a std::bind and
    	copying that.

Diff:
---
 gdb/ChangeLog                   | 7 +++++++
 gdb/common/forward-scope-exit.h | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 453677e..e8e0128 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2019-01-24  Pedro Alves  <palves@redhat.com>
+
+	* common/forward-scope-exit.h
+	(forward_scope_exit::forward_scope_exit): Pass arguments to
+	m_bind_function directly, instead of creating a std::bind and
+	copying that.
+
 2019-01-24  Alan Hayward  <alan.hayward@arm.com>
 
 	* aarch64-tdep.c (aapcs_is_vfp_call_or_return_candidate_1): Check
diff --git a/gdb/common/forward-scope-exit.h b/gdb/common/forward-scope-exit.h
index 8d63915..bffc6e6 100644
--- a/gdb/common/forward-scope-exit.h
+++ b/gdb/common/forward-scope-exit.h
@@ -95,7 +95,7 @@ class forward_scope_exit<Function, function, Res (Args...)>
 
 public:
   explicit forward_scope_exit (Args ...args)
-    : m_bind_function (std::bind (function, args...))
+    : m_bind_function (function, args...)
   {
     /* Nothing.  */
   }