Re: [PATCH] Add initializers to bound_minimal_symbol

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2022-02-16 09:31, Enze Li wrote:
> Hi Tom,
> 
> I also encountered a similar error message when I compiled with clang.Then I found this thread that you are discussing. 
> 
> I use the following commands to build,
> $ ./configure --prefix=`pwd`/build CC=clang CXX=clang++ \
>   CXXFLAGS=-std=gnu++11 --disable-unit-tests
> 
> It says,
> =====================================================================
>   CXX    macroscope.o
> linespec.c:4276:31: error: no matching constructor for initialization
> of 'struct bound_minimal_symbol'
>   struct bound_minimal_symbol mo = {minsym, objfile};
>                               ^    ~~~~~~~~~~~~~~~~~
> ./minsyms.h:29:8: note: candidate constructor (the implicit copy
> constructor) not viable: requires 1 argument, but 2 were provided
> struct bound_minimal_symbol
>        ^
> ./minsyms.h:29:8: note: candidate constructor (the implicit move
> constructor) not viable: requires 1 argument, but 2 were provided
> ./minsyms.h:29:8: note: candidate constructor (the implicit default
> constructor) not viable: requires 0 arguments, but 2 were provided
> =====================================================================
> 
> On Tue, 2022-02-15 at 08:41 -0700, Tom Tromey via Gdb-patches wrote:
>> Simon> Hmm, I see this with g++-11:
>>
>> I'm also using gcc 11 and I don't see this error.
> 
> It seems that Simon is referring to the use of the C++11 standard.

I didn't mean to, but I think you are right.  This build of mine has
-std=c++11 in CXXFLAGS, which I added exactly to catch these issues
(since the recent compilers default to a more recent C++).

>> I wrote the appended and this also built fine.  But I don't know ifit
>> would work for you.
>>
>> Tom
> 
> With the appended patch, it built fine for me with clang.  And I also
> tested it with gcc-11 as Simon did and again there were no problems.
> 
> $ ./configure --prefix=`pwd`/build CXXFLAGS=-std=gnu++11 \
>   --disable-unit-tests
> 
> BTW, all tests were conducted on the latest openSUSE Tumbleweed.
> It has:
> - gcc (SUSE Linux) 11.2.1 20220103
> - clang version 13.0.1

LGTM too, thanks.

I would just suggest changing the call in add_minsym like so:

-  struct bound_minimal_symbol mo = {minsym, objfile};
-  msyms->push_back (mo);
+  msyms->emplace_back (minsym, objfile);

This just avoids constructing the object and then copying it.

Simon