[Bug lto/84847] [8 Regression] Incompatibility between early LTO debug and "-Wl,--gc-sections" leads to corrupt DWARF debuginfo

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84847

--- Comment #19 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to rguenther@suse.de from comment #11)

> Nah, just the following - you removed LTO testing of prettyprinters
> 
> Index: libstdc++-v3/testsuite/libstdc++-prettyprinters/prettyprinters.exp
> ===================================================================
> --- libstdc++-v3/testsuite/libstdc++-prettyprinters/prettyprinters.exp  
> (revision 258481)
> +++ libstdc++-v3/testsuite/libstdc++-prettyprinters/prettyprinters.exp  
> (working copy)
> @@ -50,7 +50,7 @@ gdb-dg-runtest [lsort [glob $srcdir/$sub
>  if { [check_effective_target_lto] } {
>    append cxxflags " -flto"
>    # work around sourceware.org 20882
> -  regsub {^(.*)-Wl,--gc-sections(.*)$} $cxxldflags {\1\2} cxxldflags
> +  #regsub {^(.*)-Wl,--gc-sections(.*)$} $cxxldflags {\1\2} cxxldflags
>    gdb-dg-runtest [lsort [glob $srcdir/$subdir/*.cc]] \
>      "" "$DEFAULT_CXXFLAGS -flto $PCH_CXXFLAGS"
>  }

With this patch applied:

https://sourceware.org/ml/binutils/2018-03/msg00175.html

I got

# of expected passes            140

                === libstdc++ Summary ===

# of expected passes            201