Re: link errors with GNAT GPL 2016 and gprof

[Anh Vo <anhvofrcaus@gmail.com>]

On Saturday, September 2, 2017 at 3:02:48 PM UTC-7, Stephen Leake wrote:
> I'm trying to Do The Right Thing and profile my code before I start messing with it to make it faster. But GNAT is _not_ cooperating!
> 
> According to the gnat user guide, to use gprof, we compile as:
> 
>    gnatmake -f -pg -P <project.gpr>
> 
> That fails with GNAT GPL 2016:
> 
> gprbuild: illegal option "-pg" on the command line
> 
> So I added "-pg" in the Builder package in the project file:
> 
>    package Builder is
>       case Profile is
>       when "Full" =>
>          for Default_Switches ("Ada") use ("-f", "-pg");
> 
>       when "On" =>
>          for Default_Switches ("Ada") use ("-pg");
> 
>       when "Off" =>
>          null;
>       end case;
> 
>    end Builder;
> 
> That gives -pg options on each 'gcc' command, but fails at link time:
> 
> gcc run_ada_lite_parser.o -o run_ada_lite_parser.exe
> run_ada_lite_parser.o: In function `ada_run_ada_lite_parser':
> C:/Projects/org.wisitoken.stephe-1/wisi/test/run_ada_lite_parser.adb:12: undefined reference to `mcount'
> 
> I noticed there is no '-pg' on the 'gcc' link command line, so I added it to the Linker package:
> 
>    package Linker is
>       case Profile is
>       when "Full" | "On" =>
>          for Default_Switches ("Ada") use ("-pg");
> 
>       when "Off" =>
>          null;
>       end case;
> 
>    end Linker;
> 
> That did not help. Also tried adding it to the Binder package; no help there either.
> 
> How do I tell gprbuild to specify "-pg" for linking?
> 
> The gnat user guide has always been unhelpful about mapping command line options to project file packages.
> 
> -- Stephe

In order to pass switches to the linker thru gnatmake, use -largs opts according to gnatmake --help shown. Could you try this?

Anh Vo