| Message ID | 20180628230025.jxhojynvjhshu7t3@delia |
|---|---|
| State | New |
| Headers | show |
| Series | [testsuite/guality] Don't use attribute used in pr45882.c for -O0 | expand |
On 06/28/2018 05:00 PM, Tom de Vries wrote: > [ was: Re: [testsuite] Fix guality/pr45882.c for flto ] > > On Thu, Jun 21, 2018 at 02:52:31PM +0200, Richard Biener wrote: >> On Thu, 21 Jun 2018, Tom de Vries wrote: >> >>> Hi, >>> >>> Atm this test in pr45882.c: >>> ... >>> int d = a[i]; /* { dg-final { gdb-test 16 "d" "112" } } */ >>> ... >>> fails as follows with -flto: >>> ... >>> FAIL: gcc.dg/guality/pr45882.c -O2 -flto -fuse-linker-plugin \ >>> -fno-fat-lto-objects line 16 d == 112 >>> ... >>> >>> In more detail, gdb fails to print the value of d: >>> ... >>> Breakpoint 1, foo (i=i@entry=7, j=j@entry=7) at pr45882.c:16 >>> 16 ++v; >>> $1 = <optimized out> >>> $2 = 112 >>> <optimized out> != 112 >>> ... >>> >>> Variable d is a local variable in function foo, initialized from global array a. >>> When compiling, first cddce1 removes the initialization of d in foo, given >>> that d is not used afterwards. Then ipa marks array a as write-only, and >>> removes the stores to array a in main. This invalidates the location >>> expression for d, which points to a[i], so it is removed, which is why gdb >>> ends up printing <optimized out> for d. >>> >>> This patches fixes the fail by adding attribute used to array a, preventing >>> array a from being marked as write-only. >>> >>> Tested on x86_64. >>> >>> OK for trunk? >> >> OK. >> > > I committed this patch, but thought about it some more, and realized that this > is the right solution for optimized code, but not for non-optimized code. > > For optimized code, we generate debug info, but as best effort, and we might > need to inhibit the optimizers here and there by adding attribute used and > volatile etc in testcases, in order to allow sufficient debug information to > be generated. > > But for non-optimized code (-O0), we shouldn't need such additions in the > testcases, since we're not supposed to optimize in the first place. > > So, this patch conditionalizes attribute used in pr45882.c, depending on > whether we're optimizing or not. > > This patch as is makes the test-case fail due to adding lines in front of > gdb-test, and gdb-test using absolute line numbers. So, we either need > "[testsuite/guality] Use line number vars in gdb-test" ( > https://gcc.gnu.org/ml/gcc-patches/2018-06/msg01825.html ), or the absolute > line numbers need to be updated. > > OK for trunk if bootstrap and reg-test succeeds? > > Thanks, > - Tom > > [testsuite/guality] Don't use attribute used in pr45882.c for -O0 > > 2018-06-28 Tom de Vries <tdevries@suse.de> > > * gcc.dg/guality/guality.exp (guality_transform_options): New proc. > (toplevel): Apply guality_transform_options on DG_TORTURE_OPTIONS and > LTO_TORTURE_OPTIONS. > * gcc.dg/guality/prevent-optimization.h: New file. > * gcc.dg/guality/pr45882.c: Include prevent-optimization.h. > (a): Replace __attribute__((used)) with ATTRIBUTE_USED. OK. Jeff
diff --git a/gcc/testsuite/gcc.dg/guality/guality.exp b/gcc/testsuite/gcc.dg/guality/guality.exp index 04e889caa2f..d9994341477 100644 --- a/gcc/testsuite/gcc.dg/guality/guality.exp +++ b/gcc/testsuite/gcc.dg/guality/guality.exp @@ -48,6 +48,28 @@ if ![info exists ::env(GUALITY_GDB_NAME)] { } report_gdb $::env(GUALITY_GDB_NAME) [info script] +proc guality_transform_options { args } { + set res [list] + foreach opt [lindex $args 0] { + # + if { ! [regexp -- "-O0" $opt] } { + set opt "$opt -DPREVENT_OPTIMIZATION" + } + lappend res $opt + } + + return $res +} + +global DG_TORTURE_OPTIONS +set guality_dg_torture_options [guality_transform_options $DG_TORTURE_OPTIONS] +set guality_lto_torture_options [guality_transform_options $LTO_TORTURE_OPTIONS] +torture-init +set-torture-options \ + $guality_dg_torture_options \ + [list {}] \ + $guality_lto_torture_options + if {[check_guality " #include \"$srcdir/$subdir/guality.h\" volatile long int varl = 6; @@ -65,4 +87,5 @@ if [info exists guality_gdb_name] { unsetenv GUALITY_GDB_NAME } +torture-finish dg-finish diff --git a/gcc/testsuite/gcc.dg/guality/pr45882.c b/gcc/testsuite/gcc.dg/guality/pr45882.c index ece35238a30..47572f6a7a4 100644 --- a/gcc/testsuite/gcc.dg/guality/pr45882.c +++ b/gcc/testsuite/gcc.dg/guality/pr45882.c @@ -2,8 +2,10 @@ /* { dg-do run } */ /* { dg-options "-g" } */ +#include "prevent-optimization.h" + extern void abort (void); -int a[1024] __attribute__((used)); +int a[1024] ATTRIBUTE_USED; volatile short int v; __attribute__((noinline,noclone,used)) int diff --git a/gcc/testsuite/gcc.dg/guality/prevent-optimization.h b/gcc/testsuite/gcc.dg/guality/prevent-optimization.h new file mode 100644 index 00000000000..0ef84a3d9c8 --- /dev/null +++ b/gcc/testsuite/gcc.dg/guality/prevent-optimization.h @@ -0,0 +1,28 @@ +/* Copyright (C) 2018 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC 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, or (at your option) +any later version. + +GCC 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/>. */ + +#ifndef PREVENT_OPTIMIZATION_H +#define PREVENT_OPTIMIZATION_H + +#ifdef PREVENT_OPTIMIZATION +#define ATTRIBUTE_USED __attribute__((used)) +#else +#define ATTRIBUTE_USED +#endif + +#endif