Re: [PATCH] Specialize std::hash for ptid_t

[Vaseeharan Vinayagamoorthy <Vaseeharan.Vinayagamoorthy@arm.com>]

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Hello Tom,

It does build ok with GCC 7.5.
Has the minimum required version for building GDB changed?
At least for GCC, the minimum requirement seems to be 4.8: https://gcc.gnu.org/install/prerequisites.html


Kind regards,
Vasee
________________________________
From: Tom Tromey <tromey@adacore.com>
Sent: 14 September 2023 20:33
To: Vaseeharan Vinayagamoorthy <Vaseeharan.Vinayagamoorthy@arm.com>
Cc: Tom Tromey <tromey@adacore.com>; Simon Marchi <simon.marchi@polymtl.ca>; gdb-patches@sourceware.org <gdb-patches@sourceware.org>
Subject: Re: [PATCH] Specialize std::hash for ptid_t

>>>>> Vaseeharan Vinayagamoorthy <Vaseeharan.Vinayagamoorthy@arm.com> writes:

> I think that after this patch is when I am seeing these errors when
> building cross toolchains, for arm-none-eabi and aarch64-none-elf,
> using gcc 4.8.

Can you try a newer gcc?

> /…/src/binutils-gdb--gdb/gdbsupport/ptid.h:161:13: error: specialization of ‘template<class _Tp> struct std::hash’ in different namespace [-fpermissive]

Or, alternatively, try the appended?

Tom

diff --git a/gdbsupport/ptid.h b/gdbsupport/ptid.h
index f8644d47633..96c7d9c8bfd 100644
--- a/gdbsupport/ptid.h
+++ b/gdbsupport/ptid.h
@@ -157,8 +157,10 @@ class ptid_t
   tid_type m_tid;
 };

+namespace std
+{
 template<>
-struct std::hash<ptid_t>
+struct hash<ptid_t>
 {
   size_t operator() (const ptid_t &ptid) const
   {
@@ -169,6 +171,7 @@ struct std::hash<ptid_t>
             + long_hash (ptid.tid ()));
   }
 };
+}

 /* The null or zero ptid, often used to indicate no process. */