Re: [PATCH][gdb/testsuite] Don't pass -fPIC to gdb_compile_shlib

[Simon Marchi <simark@simark.ca>]

On 2020-12-07 7:20 a.m., Tom de Vries wrote:
> Hi,
>
> When running test-case gdb.base/info-shared.exp, I see in gdb.log:
> ...
> Executing on host: \
>   gcc ... -fPIC -fpic -c -o info-shared-solib1.c.o info-shared-solib1.c
> ...
>
> The -fPIC comes from the test-case:
> ...
> if { [gdb_compile_shlib $srcfile_lib1 $binfile_lib1 \
>          [list additional_flags=-fPIC]] != "" } {
> ...
> but the -fpic, which overrides the -fPIC comes from gdb_compile_shlib.
>
> The proc gdb_compile_shlib adds the -fpic or similar dependent on platform
> and compiler.  However, in some cases it doesn't add anything, which is
> probably why all those test-case pass -fPIC.
>
> Fix this by removing -fPIC from all the calls to gdb_compile_shlib, and
> ensuring that gdb_compile_shlib takes care of adding it, if required.
>
> Tested on x86_64-linux.
>
> Any comments?

I agree with the direction, where the test cases themselves should
encode the least knowledge as possible about how to compile things.  So
from my point of view, this LGTM.  Just one formatting nit below.

> diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
> index e413bab93c..e35d236018 100644
> --- a/gdb/testsuite/lib/gdb.exp
> +++ b/gdb/testsuite/lib/gdb.exp
> @@ -4304,17 +4304,21 @@ proc gdb_compile_shlib {sources dest options} {
>              lappend obj_options "additional_flags=-qpic"
>          }
>  	"clang-*" {
> -	    if { !([istarget "*-*-cygwin*"]
> -		   || [istarget "*-*-mingw*"]) } {
> +	    if { [istarget "*-*-cygwin*"]
> +		 || [istarget "*-*-mingw*"] } {
> +		lappend obj_options "additional_flags=-fPIC"
> +	    } else {
>  		lappend obj_options "additional_flags=-fpic"
>  	    }
>  	}
>          "gcc-*" {
> -            if { !([istarget "powerpc*-*-aix*"]
> +            if { [istarget "powerpc*-*-aix*"]
>                     || [istarget "rs6000*-*-aix*"]
>                     || [istarget "*-*-cygwin*"]
>                     || [istarget "*-*-mingw*"]
> -                   || [istarget "*-*-pe*"]) } {
> +		 || [istarget "*-*-pe*"] } {

The last line is not aligned with the others.  I never know how to
properly wrap TCL code, but you can at least make them aligned with the
existing ones.

Simon