[PATCH 1/2] gdbsupport: use result_of_t instead of result_of in parallel-for.h

[PATCH 1/2] gdbsupport: use result_of_t instead of result_of in parallel-for.h

[Simon Marchi]

When building with -std=c++11, I get:

In file included from /home/smarchi/src/binutils-gdb/gdb/unittests/parallel-for-selftests.c:22:                                                                             /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/parallel-for.h:134:10: error: ‘result_of_t’ is not a member of ‘std’; did you mean ‘result_of’?
  134 |     std::result_of_t<RangeFunction (RandomIt, RandomIt)>
      |          ^~~~~~~~~~~
      |          result_of

This is because result_of_t has been introduced in C++14.  Use the
equivalent result_of<...>::type instead.

result_of and result_of_t have been removed in C++20 though, so I think
we'll need some patches eventually to make the code use invoke_result
instead, depending on the C++ version.

Change-Id: I4817f361c0ebcdd4b32976898fc368bb302b61b9
---
 gdbsupport/parallel-for.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/gdbsupport/parallel-for.h b/gdbsupport/parallel-for.h
index 44303abb716..713ec660306 100644
--- a/gdbsupport/parallel-for.h
+++ b/gdbsupport/parallel-for.h
@@ -131,13 +131,13 @@ struct par_for_accumulator<void>
 
 template<class RandomIt, class RangeFunction>
 typename gdb::detail::par_for_accumulator<
-    std::result_of_t<RangeFunction (RandomIt, RandomIt)>
+    typename std::result_of<RangeFunction (RandomIt, RandomIt)>::type
   >::result_type
 parallel_for_each (unsigned n, RandomIt first, RandomIt last,
 		   RangeFunction callback)
 {
-  typedef typename std::result_of_t<RangeFunction (RandomIt, RandomIt)>
-    result_type;
+  using result_type
+    = typename std::result_of<RangeFunction (RandomIt, RandomIt)>::type;
 
   size_t n_threads = thread_pool::g_thread_pool->thread_count ();
   size_t n_elements = last - first;
-- 
2.35.1

[PATCH 2/2] gdb: use decltype instead of typeof in dwarf2/read.c

[Simon Marchi]

When building with -std=c++11, I get:

  CXX    dwarf2/read.o
/home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c: In function ‘void dwarf2_build_psymtabs_hard(dwarf2_per_objfile*)’:
/home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:7130:23: error: expected type-specifier before ‘typeof’
 7130 |     using iter_type = typeof (per_bfd->all_comp_units.begin ());
      |                       ^~~~~~

This is because typeof is a GNU extension.  Use C++'s decltype keyword
instead.

Change-Id: Ieca2e8d25e50f71dc6c615a405a972a54de3ef14
---
 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 9e8527a7fc1..7c148aecdf5 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -7127,7 +7127,7 @@ dwarf2_build_psymtabs_hard (dwarf2_per_objfile *per_objfile)
     /* Ensure that complaints are handled correctly.  */
     complaint_interceptor complaint_handler;
 
-    using iter_type = typeof (per_bfd->all_comp_units.begin ());
+    using iter_type = decltype (per_bfd->all_comp_units.begin ());
 
     /* Each thread returns a pair holding a cooked index, and a vector
        of errors that should be printed.  The latter is done because
-- 
2.35.1

Re: [PATCH 1/2] gdbsupport: use result_of_t instead of result_of in parallel-for.h

[Tom Tromey]

>>>>> "Simon" == Simon Marchi via Gdb-patches <gdb-patches@sourceware.org> writes:

Simon> This is because result_of_t has been introduced in C++14.  Use the
Simon> equivalent result_of<...>::type instead.

Thank you, please check this in.

Tom

Re: [PATCH 2/2] gdb: use decltype instead of typeof in dwarf2/read.c

[Tom Tromey]

>>>>> "Simon" == Simon Marchi via Gdb-patches <gdb-patches@sourceware.org> writes:

Simon> This is because typeof is a GNU extension.  Use C++'s decltype keyword
Simon> instead.

Ugh, sorry about that.  Please check this in.

Tom

Re: [PATCH 1/2] gdbsupport: use result_of_t instead of result_of in parallel-for.h

[Simon Marchi]

On 2022-04-12 13:36, Tom Tromey wrote:
>>>>>> "Simon" == Simon Marchi via Gdb-patches <gdb-patches@sourceware.org> writes:
> 
> Simon> This is because result_of_t has been introduced in C++14.  Use the
> Simon> equivalent result_of<...>::type instead.
> 
> Thank you, please check this in.
> 
> Tom

Pushed both patches, thanks.

Simon