[binutils-gdb] gdb/dwarf2/read.c: remove pessimizing std::move

[binutils-gdb] gdb/dwarf2/read.c: remove pessimizing std::move

[Simon Marchi]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ff191ddf80a2bcb81e0ef0208a961f98e72fe719

commit ff191ddf80a2bcb81e0ef0208a961f98e72fe719
Author: Simon Marchi <simon.marchi@efficios.com>
Date:   Mon Apr 22 15:01:37 2024 -0400

    gdb/dwarf2/read.c: remove pessimizing std::move
    
    When building with this clang:
    
        $ c++ --version
        FreeBSD clang version 16.0.6 (https://github.com/llvm/llvm-project.git llvmorg-16.0.6-0-g7cbf1a259152)
    
    I see:
    
        $ gmake
          CXX    dwarf2/read.o
        /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:4890:6: error: moving a temporary object prevents copy elision [-Werror,-Wpessimizing-move]
                                                std::move (thread_storage.release_parent_map ()));
                                                ^
        /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:4890:6: note: remove std::move call here
                                                std::move (thread_storage.release_parent_map ()));
                                                ^~~~~~~~~~~                                    ~
    
    The compiler seems right, there is not need to std::move the result of
    `release_parent_map ()`, it's already going to be an rvalue.  Remove the
    std::move.
    
    The issue isn't FreeBSD-specific, I see it on Linux as well when
    building hwith clang, I just noticed it on a FreeBSD build first.
    
    Change-Id: I7aa20a4db56c799f20d838ad08099a01653bba19
    Approved-By: Tom Tromey <tom@tromey.com>

Diff:
---
 gdb/dwarf2/read.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index af69e1d9d9e..96e51bb42b0 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -4885,7 +4885,7 @@ cooked_index_debug_info::process_cus (size_t task_number, unit_iterator first,
   m_results[task_number] = result_type (thread_storage.release (),
 					complaint_handler.release (),
 					std::move (errors),
-					std::move (thread_storage.release_parent_map ()));
+					thread_storage.release_parent_map ());
 }
 
 void