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

[rguenther at suse dot de]

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

--- Comment #11 from rguenther at suse dot de <rguenther at suse dot de> ---
On Tue, 13 Mar 2018, hjl.tools at gmail dot com wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84847
> 
> --- Comment #9 from H.J. Lu <hjl.tools at gmail dot com> ---
> (In reply to rguenther@suse.de from comment #6)
> > 
> > make check-target-libstdc++-v3 RUNTESTFLAGS="prettyprinters.exp"
> 
> I tried:
> 
> diff --git a/libstdc++-v3/testsuite/libstdc++-prettyprinters/prettyprinters.exp
> b/libstdc++-v3/testsuite/libstdc++-prettyprinters/prettyprinters.exp
> index c51b1ffb21c..fab6ef11947 100644
> --- a/libstdc++-v3/testsuite/libstdc++-prettyprinters/prettyprinters.exp
> +++ b/libstdc++-v3/testsuite/libstdc++-prettyprinters/prettyprinters.exp
> @@ -47,14 +47,6 @@ global PCH_CXXFLAGS
>  gdb-dg-runtest [lsort [glob $srcdir/$subdir/*.cc]] \
>    "" "$DEFAULT_CXXFLAGS $PCH_CXXFLAGS"
> 
> -if { [check_effective_target_lto] } {
> -  append cxxflags " -flto"
> -  # work around sourceware.org 20882
> -  regsub {^(.*)-Wl,--gc-sections(.*)$} $cxxldflags {\1\2} cxxldflags
> -  gdb-dg-runtest [lsort [glob $srcdir/$subdir/*.cc]] \
> -    "" "$DEFAULT_CXXFLAGS -flto $PCH_CXXFLAGS"
> -}
> -
>  if [info exists guality_gdb_name] {
>      unsetenv GUALITY_GDB_NAME
>  }

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"
 }