Re: [PATCH] PR61123 : Fix the ABI mis-matching error caused by LTO

[Richard Biener <richard.guenther@gmail.com>]

On Wed, Jun 18, 2014 at 10:14 AM, Hale Wang <Hale.Wang@arm.com> wrote:
> Hi,
>
> With LTO, -fno-short-enums is ignored, resulting in ABI mis-matching in
> linking.
>
> Refer https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61123  for details.
>
> This patch add fshort-enums and fshout-wchar to LTO group.
>
> To check it, a new procedure object-readelf is added in
> testsuite/lib/lto.exp and new lto tests are added in gcc.target/arm/lto.
>
> Bootstrap and no make check regression on X86-64.
>
> Patch also attached for convenience.  Is It ok for trunk?
>
> Thanks and Best Regards,
> Hale Wang
>
> c-family/ChangeLog
> 2014-06-18 Hale Wang <hale.wang@arm.com>
>
>                     PR lto/61123
>                     *c.opt (fshort-enums): Add to LTO.
>                     *c.opt (fshort-wchar): Likewise.

Space after the *.

I think you don't need to copy the LTO harness but you can simply
use dg.exp and sth similar to gcc.dg/20081223-1.c (there is an
effective target 'lto' to guard for lto support).

So simply place the testcase in gcc.target/arm/ (make sure to
put a dg-do compile on the 2nd file and use dg-additional-sources).

If that doesn't work I'd say put the testcase in gcc.dg/lto/ instead
and do a dg-skip-if for non-arm targets.

Ok with one of those changes.

Thanks,
Richard.

> testsuite/ChangeLog
> 2014-06-18 Hale Wang <hale.wang@arm.com>
>
>                     * gcc.target/arm/lto/: New folder to verify the LTO
> option for ARM specific.
>                     * gcc.target/arm/lto/pr61123-enum-size_0.c: New test
> case.
>                     * gcc.target/arm/lto/pr61123-enum-size_1.c: Likewise.
>                     * gcc.target/arm/lto/lto.exp: New exp file used to test
> LTO option for ARM specific.
>                     * lib/lto.exp (object-readelf): New procedure used to
> catch the enum size in the final executable.
>
> Index: gcc/c-family/c.opt
> ===================================================================
> --- gcc/c-family/c.opt     (revision 211394)
> +++ gcc/c-family/c.opt  (working copy)
> @@ -1189,11 +1189,11 @@
> Use the same size for double as for float
>
>  fshort-enums
> -C ObjC C++ ObjC++ Optimization Var(flag_short_enums)
> +C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
> Use the narrowest integer type possible for enumeration types
>
>  fshort-wchar
> -C ObjC C++ ObjC++ Optimization Var(flag_short_wchar)
> +C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
> Force the underlying type for \"wchar_t\" to be \"unsigned short\"
>
>  fsigned-bitfields
> Index: gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_0.c
> ===================================================================
> --- gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_0.c       (revision
> 0)
> +++ gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_0.c    (revision 0)
> @@ -0,0 +1,22 @@
> +/* { dg-lto-do link } */
> +/* { dg-lto-options { { -fno-short-enums -Wl,-Ur,--no-enum-size-warning -Os
> -nostdlib -flto } } } */
> +
> +#include <stdlib.h>
> +
> +enum enum_size_attribute
> +{
> +  small_size, int_size
> +};
> +
> +struct debug_ABI_enum_size
> +{
> +  enum enum_size_attribute es;
> +};
> +
> +int
> +foo1 (struct debug_ABI_enum_size *x)
> +{
> +  return sizeof (x->es);
> +}
> +
> +/* { dg-final { object-readelf Tag_ABI_enum_size int { target arm_eabi } }
> } */
> Index: gcc/testsuite/gcc.target/arm/lto/lto.exp
> ===================================================================
> --- gcc/testsuite/gcc.target/arm/lto/lto.exp        (revision 0)
> +++ gcc/testsuite/gcc.target/arm/lto/lto.exp     (revision 0)
> @@ -0,0 +1,59 @@
> +# Copyright (C) 2009-2014 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with GCC; see the file COPYING3.  If not see
> +# <http://www.gnu.org/licenses/>.
> +#
> +# Contributed by Diego Novillo <dnovillo@google.com>
> +
> +
> +# Test link-time optimization across multiple files.
> +#
> +# Programs are broken into multiple files.  Each one is compiled
> +# separately with LTO information.  The final executable is generated
> +# by collecting all the generated object files using regular LTO or WHOPR.
> +
> +if $tracelevel then {
> +    strace $tracelevel
> +}
> +
> +# Load procedures from common libraries.
> +load_lib standard.exp
> +load_lib gcc.exp
> +
> +# Load the language-independent compabibility support procedures.
> +load_lib lto.exp
> +
> +# If LTO has not been enabled, bail.
> +if { ![check_effective_target_lto] } {
> +    return
> +}
> +
> +gcc_init
> +lto_init no-mathlib
> +
> +# Define an identifier for use with this suite to avoid name conflicts
> +# with other lto tests running at the same time.
> +set sid "c_lto"
> +
> +# Main loop.
> +foreach src [lsort [find $srcdir/$subdir *_0.c]] {
> +    # If we're only testing specific files and this isn't one of them, skip
> it.
> +    if ![runtest_file_p $runtests $src] then {
> +             continue
> +    }
> +
> +    lto-execute $src $sid
> +}
> +
> +lto_finish
> Index: gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_1.c
> ===================================================================
> --- gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_1.c       (revision
> 0)
> +++ gcc/testsuite/gcc.target/arm/lto/pr61123-enum-size_1.c    (revision 0)
> @@ -0,0 +1,5 @@
> +int
> +foo2 (int y)
> +{
> +  return y*10;
> +}
> Index: gcc/testsuite/lib/lto.exp
> ===================================================================
> --- gcc/testsuite/lib/lto.exp         (revision 211394)
> +++ gcc/testsuite/lib/lto.exp      (working copy)
> @@ -650,3 +650,82 @@
>                fail "scan-symbol $args"
>      }
> }
> +
> +# Call pass if object readelf is ok, otherwise fail.
> +# example: /* { dg-final { object-readelf Tag_ABI_enum_size int} } */
> +proc object-readelf { args } {
> +    global readelf
> +    global base_dir
> +             upvar 2 execname execname
> +
> +    if { [llength $args] < 2 } {
> +                             error "object-readelf: too few arguments"
> +        return
> +    }
> +    if { [llength $args] > 3 } {
> +                             error "object-readelf: too many arguments"
> +                             return
> +    }
> +    if { [llength $args] >= 3 } {
> +             switch [dg-process-target [lindex $args 2]] {
> +                 "S" { }
> +                 "N" { return }
> +                 "F" { setup_xfail "*-*-*" }
> +                 "P" { }
> +             }
> +    }
> +
> +    # Find size like we find g++ in g++.exp.
> +    if ![info exists readelf]  {
> +             set readelf [findfile $base_dir/../../../binutils/readelf \
> +                               $base_dir/../../../binutils/readelf \
> +                               [findfile $base_dir/../../readelf
> $base_dir/../../readelf \
> +                                [findfile $base_dir/readelf
> $base_dir/readelf \
> +                                 [transform readelf]]]]
> +             verbose -log "readelf is $readelf"
> +    }
> +
> +    set what [lindex $args 0]
> +             set with [lindex $args 1]
> +
> +    if ![file_on_host exists $execname] {
> +             verbose -log "$execname does not exist"
> +             unresolved "object-readelf $what "
> +             return
> +    }
> +
> +    set output [remote_exec host "$readelf -A" "$execname"]
> +    set status [lindex $output 0]
> +    if { $status != 0 } {
> +        verbose -log "object-readelf: $readelf failed"
> +        unresolved "object-readelf $what $execname"
> +        return
> +    }
> +
> +    set text [lindex $output 1]
> +    set lines [split $text "\n"]
> +
> +             set done 0
> +             set i 0
> +             while { !$done } {
> +                             set line_tex [lindex $lines $i]
> +                             if { [llength ${line_tex}] > 1} {
> +                                             incr i
> +                                             if [regexp -- $what $line_tex]
> {
> +                                                             set match
> [regexp -- $with $line_tex]
> +                                                             set done 1
> +                                             }
> +                             } else {
> +                                             set done 1
> +                             }
> +             }
> +
> +    verbose -log "$what size is $with;"
> +    if { $match == 1 } {
> +             pass "object-readelf $what size is correct."
> +    } else {
> +             fail "object-readelf $what size is incorrect."
> +    }
> +}
> +
> +