diff mbox series

V2 [PATCH] Update check for working assembler --gdwarf-4 option

Message ID CAMe9rOpbAbepmm+iMF6opR51EWB6STdCehbyWbUDNEym9rfHjA@mail.gmail.com
State New
Headers show
Series V2 [PATCH] Update check for working assembler --gdwarf-4 option | expand

Commit Message

H.J. Lu Oct. 24, 2020, 3:28 p.m. UTC 
On Sat, Oct 17, 2020 at 6:23 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Fri, Oct 16, 2020 at 11:29 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > On Fri, Oct 16, 2020 at 11:17 AM Jakub Jelinek <jakub@redhat.com> wrote:
> > >
> > > On Fri, Oct 16, 2020 at 10:58:34AM -0700, H.J. Lu wrote:
> > > > Don't set HAVE_AS_GDWARF_5_DEBUG_FLAG nor HAVE_AS_WORKING_DWARF_4_FLAG
> > > > if there is an extra assembly input file in debug info generated by
> > > > --gdwarf-5/--gdwarf-4:
> > > >
> > > > https://sourceware.org/bugzilla/show_bug.cgi?id=25878
> > > > https://sourceware.org/bugzilla/show_bug.cgi?id=26740
> > > >
> > > > Also replace success with dwarf4_success in the 32-bit --gdwarf-4 check.
> > > >
> > > > OK for master?
> > > >
> > > >       PR bootstrap/97451
> > > >       * configure.ac (HAVE_AS_GDWARF_5_DEBUG_FLAG): Don't define if
> > > >       there is an extra assembly input file in debug info.
> > > >       (HAVE_AS_WORKING_DWARF_4_FLAG): Likewise.  Replace success with
> > > >       dwarf4_success in the 32-bit --gdwarf-4 check.
> > > >       * configure: Regenerated.
> > >
> > > The HAVE_AS_GDWARF_5_DEBUG_FLAG macro should be solely about whether
> > > -gdwarf-5 can be passed to as, nothing else.  That is because it is not only
> > > used to decide if we can pass -gdwarf-5 to as for assembly of e.g. *.c
> > > compilation, but also if we can pass it to as when gcc driver is invoked on
> > > *.s and *.S.  And in that case the problems with -gdwarf-N having unwanted
> > > effects on assembly with compiler generated .debug_info etc. sections.
> > > don't really matter.
> > >
> > > The HAVE_AS_WORKING_DWARF_4_FLAG perhaps could be renamed to
> > > ...DWARF_N_FLAG, it is meant to check for whether we can safely pass the
> > > option also for *.c etc. compilation when we emit debug info sections by the
> > > compiler.
> > >
> > > For that, the question is, are all the issues already fixed on the binutils
> > > trunk?  As in, do I get identical object files e.g. for -gdwarf-2
> >
> > Not yet.  This patch:
> >
> > https://sourceware.org/pipermail/binutils/2020-October/113744.html
> >
> > is needed for binutils master branch.  BTW, binutils 2.35 and 2.35.1 are
> > broken.
> >
> > > compilation no matter whether the compiler passes -gdwarf-2 to gas or not
> > > (assuming dwarf 2 is the default in gas) when compiling various *.c/*.C
> > > files?  Ditto for modified gas that would default to other .debug_line
> > > versions and corresponding gcc -gdwarf-N flag and passing vs. not passing
> > > that -gdwarf-N to gas?
> > >
> > > The hope is that -gdwarf-N to gas would have two functions:
> > > 1) if the assembly doesn't contain .debug* sections/.file/.loc directives,
> > >    emit debug info (mainly .debug_line) for the assembler file in order to
> > >    be able to debug those
> > > 2) if the assembly does contain .debug* sections/.file/.loc directives,
> > >    only change the version of the .debug_line generated for the .file/.loc
> > >    directives, but nothing else; keep all .debug* sections but .debug_line
> > >    as is
> >
>
> Here is the updated patch.  OK for master?
>

The updated patch to check

https://sourceware.org/bugzilla/show_bug.cgi?id=26778

OK for master?

Comments

Jakub Jelinek Oct. 24, 2020, 3:55 p.m. UTC | #1 
On Sat, Oct 24, 2020 at 08:28:08AM -0700, H.J. Lu wrote:
> The updated patch to check
> 
> https://sourceware.org/bugzilla/show_bug.cgi?id=26778
> 
> OK for master?

Ok, thanks.

> From 7130dea1f39692a8a00e48ef119233595f9284c9 Mon Sep 17 00:00:00 2001
> From: "H.J. Lu" <hjl.tools@gmail.com>
> Date: Fri, 16 Oct 2020 05:59:51 -0700
> Subject: [PATCH] Update check for working assembler --gdwarf-4 option
> 
> Rename HAVE_AS_WORKING_DWARF_4_FLAG to HAVE_AS_WORKING_DWARF_N_FLAG
> Don't set HAVE_AS_WORKING_DWARF_N_FLAG if --gdwarf-5/--gdwarf-4 generate
> an extra assembly input file in debug info from compiler generated
> .debug_line or fail with the APP marker:
> 
> https://sourceware.org/bugzilla/show_bug.cgi?id=25878
> https://sourceware.org/bugzilla/show_bug.cgi?id=26740
> https://sourceware.org/bugzilla/show_bug.cgi?id=26778
> 
> Also replace success with dwarf4_success in the 32-bit --gdwarf-4 check.
> 
> 	PR bootstrap/97451
> 	* configure.ac (HAVE_AS_WORKING_DWARF_4_FLAG): Renamed to ...
> 	(HAVE_AS_WORKING_DWARF_N_FLAG): This.  Don't define if there is
> 	an extra assembly input file in debug info.  Replace success
> 	with dwarf4_success in the 32-bit --gdwarf-4 check.
> 	* dwarf2out.c (asm_outputs_debug_line_str): Check
> 	HAVE_AS_WORKING_DWARF_N_FLAG instead of
> 	HAVE_AS_WORKING_DWARF_4_FLAG.
> 	* gcc.c (ASM_DEBUG_SPEC): Likewise.
> 	(ASM_DEBUG_OPTION_SPEC): Likewise.
> 	* config.in: Regenerated.
> 	* configure: Likewise.
> ---
>  gcc/config.in    |   6 +--
>  gcc/configure    | 106 +++++++++++++++++++++++++++++++++++++++++++++--
>  gcc/configure.ac |  59 ++++++++++++++++++++++++--
>  gcc/dwarf2out.c  |   2 +-
>  gcc/gcc.c        |   4 +-
>  5 files changed, 164 insertions(+), 13 deletions(-)
> 
> diff --git a/gcc/config.in b/gcc/config.in
> index 3657c46f349..b7c3107bfe3 100644
> --- a/gcc/config.in
> +++ b/gcc/config.in
> @@ -719,10 +719,10 @@
>  #endif
>  
>  
> -/* Define if your assembler supports --gdwarf-4 even with compiler generated
> -   .debug_line */
> +/* Define if your assembler supports --gdwarf-4/--gdwarf-5 even with compiler
> +   generated .debug_line. */
>  #ifndef USED_FOR_TARGET
> -#undef HAVE_AS_WORKING_DWARF_4_FLAG
> +#undef HAVE_AS_WORKING_DWARF_N_FLAG
>  #endif
>  
>  
> diff --git a/gcc/configure b/gcc/configure
> index abff47d30eb..f96a89e8c37 100755
> --- a/gcc/configure
> +++ b/gcc/configure
> @@ -28701,7 +28701,7 @@ fi
>  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_debug_line_32_flag" >&5
>  $as_echo "$gcc_cv_as_debug_line_32_flag" >&6; }
>  if test $gcc_cv_as_debug_line_32_flag = yes; then
> -  success=yes
> +  dwarf4_success=yes
>  fi
>  
>     else
> @@ -28741,6 +28741,7 @@ fi
>  
>     fi
>     if test $dwarf4_success = yes; then
> +     dwarf4_success=no
>       { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for --gdwarf-4 not refusing compiler generated .debug_line" >&5
>  $as_echo_n "checking assembler for --gdwarf-4 not refusing compiler generated .debug_line... " >&6; }
>  if ${gcc_cv_as_dwarf_4_debug_line_flag+:} false; then :
> @@ -28772,9 +28773,7 @@ fi
>  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_dwarf_4_debug_line_flag" >&5
>  $as_echo "$gcc_cv_as_dwarf_4_debug_line_flag" >&6; }
>  if test $gcc_cv_as_dwarf_4_debug_line_flag = yes; then
> -
> -$as_echo "#define HAVE_AS_WORKING_DWARF_4_FLAG 1" >>confdefs.h
> -
> +  dwarf4_success=yes
>  fi
>  
>       break
> @@ -28785,6 +28784,105 @@ fi
>     dwarf4_line_sz=5
>   done
>  
> + if test $dwarf4_success = yes; then
> +   conftest_s="\
> +	.file	\"foo.c\"
> +	.text
> +bar:
> +#APP
> +# 82 \"xxx.h\" 1
> +	$insn
> +# 0 \"\" 2
> +#NO_APP
> +	$insn
> +foo:
> +	.file 1 \"foo.c\"
> +	$insn
> +	.file 2 \"foo.h\"
> +	ret
> +"
> +   dwarf4_success=no
> +   { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for --gdwarf-4 with the APP marker" >&5
> +$as_echo_n "checking assembler for --gdwarf-4 with the APP marker... " >&6; }
> +if ${gcc_cv_as_dwarf_4_app_flag+:} false; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  gcc_cv_as_dwarf_4_app_flag=no
> +  if test x$gcc_cv_as != x; then
> +    $as_echo "$conftest_s" > conftest.s
> +    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --gdwarf-4 -o conftest.o conftest.s >&5'
> +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> +  (eval $ac_try) 2>&5
> +  ac_status=$?
> +  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> +  test $ac_status = 0; }; }
> +    then
> +	gcc_cv_as_dwarf_4_app_flag=yes
> +    else
> +      echo "configure: failed program was" >&5
> +      cat conftest.s >&5
> +    fi
> +    rm -f conftest.o conftest.s
> +  fi
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_dwarf_4_app_flag" >&5
> +$as_echo "$gcc_cv_as_dwarf_4_app_flag" >&6; }
> +if test $gcc_cv_as_dwarf_4_app_flag = yes; then
> +  dwarf4_success=yes
> +fi
> +
> + fi
> +
> + if test $dwarf4_success = yes; then
> +   conftest_s="\
> +	.text
> +	.globl	foo
> +	.type	foo, %function
> +foo:
> +	$insn
> +	.size	foo, .-foo
> +	.file	1 \"foo.c\"
> +"
> +   { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for working --gdwarf-4/--gdwarf-5 for all sources" >&5
> +$as_echo_n "checking assembler for working --gdwarf-4/--gdwarf-5 for all sources... " >&6; }
> +if ${gcc_cv_as_working_gdwarf_n_flag+:} false; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  gcc_cv_as_working_gdwarf_n_flag=no
> +  if test x$gcc_cv_as != x; then
> +    $as_echo "$conftest_s" > conftest.s
> +    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --gdwarf-4 -o conftest.o conftest.s >&5'
> +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> +  (eval $ac_try) 2>&5
> +  ac_status=$?
> +  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> +  test $ac_status = 0; }; }
> +    then
> +	      if test x$gcc_cv_readelf != x \
> +	 && $gcc_cv_readelf -w conftest.o 2>&1 \
> +		| grep conftest.s > /dev/null 2>&1; then
> +	gcc_cv_as_working_gdwarf_n_flag=no
> +      else
> +	gcc_cv_as_working_gdwarf_n_flag=yes
> +      fi
> +          else
> +      echo "configure: failed program was" >&5
> +      cat conftest.s >&5
> +    fi
> +    rm -f conftest.o conftest.s
> +  fi
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_working_gdwarf_n_flag" >&5
> +$as_echo "$gcc_cv_as_working_gdwarf_n_flag" >&6; }
> +
> +
> +   if test $gcc_cv_as_working_gdwarf_n_flag = yes; then
> +
> +$as_echo "#define HAVE_AS_WORKING_DWARF_N_FLAG 1" >>confdefs.h
> +
> +   fi
> + fi
> +
>   { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for --gstabs option" >&5
>  $as_echo_n "checking assembler for --gstabs option... " >&6; }
>  if ${gcc_cv_as_gstabs_flag+:} false; then :
> diff --git a/gcc/configure.ac b/gcc/configure.ac
> index 26a5d8e3619..9154a5475dc 100644
> --- a/gcc/configure.ac
> +++ b/gcc/configure.ac
> @@ -5364,7 +5364,7 @@ foo:
>       gcc_GAS_CHECK_FEATURE([assembly of compiler generated 32-bit .debug_line],
>        gcc_cv_as_debug_line_32_flag,
>        [elf,2,36,0], [], [$conftest_s],,
> -      [success=yes])
> +      [dwarf4_success=yes])
>     else
>       gcc_GAS_CHECK_FEATURE([assembly of compiler generated 64-bit .debug_line],
>        gcc_cv_as_debug_line_64_flag,
> @@ -5372,11 +5372,11 @@ foo:
>        [dwarf4_success=yes])
>     fi
>     if test $dwarf4_success = yes; then
> +     dwarf4_success=no
>       gcc_GAS_CHECK_FEATURE([--gdwarf-4 not refusing compiler generated .debug_line],
>        gcc_cv_as_dwarf_4_debug_line_flag,
>        [elf,2,36,0], [--gdwarf-4], [$conftest_s],,
> -      [AC_DEFINE(HAVE_AS_WORKING_DWARF_4_FLAG, 1,
> -[Define if your assembler supports --gdwarf-4 even with compiler generated .debug_line])])
> +      [dwarf4_success=yes])
>       break
>     fi
>     dwarf4_debug_info_size=0x36
> @@ -5385,6 +5385,59 @@ foo:
>     dwarf4_line_sz=5
>   done
>  
> + if test $dwarf4_success = yes; then
> +   conftest_s="\
> +	.file	\"foo.c\"
> +	.text
> +bar:
> +#APP
> +# 82 \"xxx.h\" 1
> +	$insn
> +# 0 \"\" 2
> +#NO_APP
> +	$insn
> +foo:
> +	.file 1 \"foo.c\"
> +	$insn
> +	.file 2 \"foo.h\"
> +	ret
> +"
> +   dwarf4_success=no
> +   gcc_GAS_CHECK_FEATURE([--gdwarf-4 with the APP marker],
> +     gcc_cv_as_dwarf_4_app_flag,,
> +     [--gdwarf-4], [$conftest_s],, [dwarf4_success=yes])
> + fi
> +
> + if test $dwarf4_success = yes; then
> +   conftest_s="\
> +	.text
> +	.globl	foo
> +	.type	foo, %function
> +foo:
> +	$insn
> +	.size	foo, .-foo
> +	.file	1 \"foo.c\"
> +"
> +   gcc_GAS_CHECK_FEATURE([working --gdwarf-4/--gdwarf-5 for all sources],
> +     gcc_cv_as_working_gdwarf_n_flag,,
> +     [--gdwarf-4],
> +     [$conftest_s],
> +     [changequote(,)dnl
> +      if test x$gcc_cv_readelf != x \
> +	 && $gcc_cv_readelf -w conftest.o 2>&1 \
> +		| grep conftest.s > /dev/null 2>&1; then
> +	gcc_cv_as_working_gdwarf_n_flag=no
> +      else
> +	gcc_cv_as_working_gdwarf_n_flag=yes
> +      fi
> +      changequote([,])dnl])
> +   if test $gcc_cv_as_working_gdwarf_n_flag = yes; then
> +     AC_DEFINE(HAVE_AS_WORKING_DWARF_N_FLAG, 1,
> +[Define if your assembler supports --gdwarf-4/--gdwarf-5 even with
> + compiler generated .debug_line.])
> +   fi
> + fi
> +
>   gcc_GAS_CHECK_FEATURE([--gstabs option],
>    gcc_cv_as_gstabs_flag,
>    [elf,2,11,0], [--gstabs], [$insn],,
> diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
> index ba93a6c3d81..534877babfb 100644
> --- a/gcc/dwarf2out.c
> +++ b/gcc/dwarf2out.c
> @@ -11884,7 +11884,7 @@ asm_outputs_debug_line_str (void)
>      return true;
>    else
>      {
> -#if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_4_FLAG)
> +#if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_N_FLAG)
>        return !dwarf_split_debug_info && dwarf_version >= 5;
>  #else
>        return false;
> diff --git a/gcc/gcc.c b/gcc/gcc.c
> index 337c27442a3..cdf4d4f2403 100644
> --- a/gcc/gcc.c
> +++ b/gcc/gcc.c
> @@ -880,7 +880,7 @@ proper position among the other output files.  */
>  /* Define ASM_DEBUG_SPEC to be a spec suitable for translating '-g'
>     to the assembler, when compiling assembly sources only.  */
>  #ifndef ASM_DEBUG_SPEC
> -# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_4_FLAG)
> +# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_N_FLAG)
>  /* If --gdwarf-N is supported and as can handle even compiler generated
>     .debug_line with it, supply --gdwarf-N in ASM_DEBUG_OPTION_SPEC rather
>     than in ASM_DEBUG_SPEC, so that it applies to both .s and .c etc.
> @@ -921,7 +921,7 @@ proper position among the other output files.  */
>  /* Define ASM_DEBUG_OPTION_SPEC to be a spec suitable for translating '-g'
>     to the assembler when compiling all sources.  */
>  #ifndef ASM_DEBUG_OPTION_SPEC
> -# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_4_FLAG)
> +# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_N_FLAG)
>  #  define ASM_DEBUG_OPTION_DWARF_OPT					\
>  	"%{%:dwarf-version-gt(4):--gdwarf-5 ;"				\
>  	"%:dwarf-version-gt(3):--gdwarf-4 ;"				\
> -- 
> 2.26.2
> 


	Jakub
diff mbox series

Patch

From 7130dea1f39692a8a00e48ef119233595f9284c9 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 16 Oct 2020 05:59:51 -0700
Subject: [PATCH] Update check for working assembler --gdwarf-4 option

Rename HAVE_AS_WORKING_DWARF_4_FLAG to HAVE_AS_WORKING_DWARF_N_FLAG
Don't set HAVE_AS_WORKING_DWARF_N_FLAG if --gdwarf-5/--gdwarf-4 generate
an extra assembly input file in debug info from compiler generated
.debug_line or fail with the APP marker:

https://sourceware.org/bugzilla/show_bug.cgi?id=25878
https://sourceware.org/bugzilla/show_bug.cgi?id=26740
https://sourceware.org/bugzilla/show_bug.cgi?id=26778

Also replace success with dwarf4_success in the 32-bit --gdwarf-4 check.

	PR bootstrap/97451
	* configure.ac (HAVE_AS_WORKING_DWARF_4_FLAG): Renamed to ...
	(HAVE_AS_WORKING_DWARF_N_FLAG): This.  Don't define if there is
	an extra assembly input file in debug info.  Replace success
	with dwarf4_success in the 32-bit --gdwarf-4 check.
	* dwarf2out.c (asm_outputs_debug_line_str): Check
	HAVE_AS_WORKING_DWARF_N_FLAG instead of
	HAVE_AS_WORKING_DWARF_4_FLAG.
	* gcc.c (ASM_DEBUG_SPEC): Likewise.
	(ASM_DEBUG_OPTION_SPEC): Likewise.
	* config.in: Regenerated.
	* configure: Likewise.
---
 gcc/config.in    |   6 +--
 gcc/configure    | 106 +++++++++++++++++++++++++++++++++++++++++++++--
 gcc/configure.ac |  59 ++++++++++++++++++++++++--
 gcc/dwarf2out.c  |   2 +-
 gcc/gcc.c        |   4 +-
 5 files changed, 164 insertions(+), 13 deletions(-)

diff --git a/gcc/config.in b/gcc/config.in
index 3657c46f349..b7c3107bfe3 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -719,10 +719,10 @@ 
 #endif
 
 
-/* Define if your assembler supports --gdwarf-4 even with compiler generated
-   .debug_line */
+/* Define if your assembler supports --gdwarf-4/--gdwarf-5 even with compiler
+   generated .debug_line. */
 #ifndef USED_FOR_TARGET
-#undef HAVE_AS_WORKING_DWARF_4_FLAG
+#undef HAVE_AS_WORKING_DWARF_N_FLAG
 #endif
 
 
diff --git a/gcc/configure b/gcc/configure
index abff47d30eb..f96a89e8c37 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -28701,7 +28701,7 @@  fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_debug_line_32_flag" >&5
 $as_echo "$gcc_cv_as_debug_line_32_flag" >&6; }
 if test $gcc_cv_as_debug_line_32_flag = yes; then
-  success=yes
+  dwarf4_success=yes
 fi
 
    else
@@ -28741,6 +28741,7 @@  fi
 
    fi
    if test $dwarf4_success = yes; then
+     dwarf4_success=no
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for --gdwarf-4 not refusing compiler generated .debug_line" >&5
 $as_echo_n "checking assembler for --gdwarf-4 not refusing compiler generated .debug_line... " >&6; }
 if ${gcc_cv_as_dwarf_4_debug_line_flag+:} false; then :
@@ -28772,9 +28773,7 @@  fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_dwarf_4_debug_line_flag" >&5
 $as_echo "$gcc_cv_as_dwarf_4_debug_line_flag" >&6; }
 if test $gcc_cv_as_dwarf_4_debug_line_flag = yes; then
-
-$as_echo "#define HAVE_AS_WORKING_DWARF_4_FLAG 1" >>confdefs.h
-
+  dwarf4_success=yes
 fi
 
      break
@@ -28785,6 +28784,105 @@  fi
    dwarf4_line_sz=5
  done
 
+ if test $dwarf4_success = yes; then
+   conftest_s="\
+	.file	\"foo.c\"
+	.text
+bar:
+#APP
+# 82 \"xxx.h\" 1
+	$insn
+# 0 \"\" 2
+#NO_APP
+	$insn
+foo:
+	.file 1 \"foo.c\"
+	$insn
+	.file 2 \"foo.h\"
+	ret
+"
+   dwarf4_success=no
+   { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for --gdwarf-4 with the APP marker" >&5
+$as_echo_n "checking assembler for --gdwarf-4 with the APP marker... " >&6; }
+if ${gcc_cv_as_dwarf_4_app_flag+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_dwarf_4_app_flag=no
+  if test x$gcc_cv_as != x; then
+    $as_echo "$conftest_s" > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --gdwarf-4 -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_dwarf_4_app_flag=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_dwarf_4_app_flag" >&5
+$as_echo "$gcc_cv_as_dwarf_4_app_flag" >&6; }
+if test $gcc_cv_as_dwarf_4_app_flag = yes; then
+  dwarf4_success=yes
+fi
+
+ fi
+
+ if test $dwarf4_success = yes; then
+   conftest_s="\
+	.text
+	.globl	foo
+	.type	foo, %function
+foo:
+	$insn
+	.size	foo, .-foo
+	.file	1 \"foo.c\"
+"
+   { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for working --gdwarf-4/--gdwarf-5 for all sources" >&5
+$as_echo_n "checking assembler for working --gdwarf-4/--gdwarf-5 for all sources... " >&6; }
+if ${gcc_cv_as_working_gdwarf_n_flag+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_working_gdwarf_n_flag=no
+  if test x$gcc_cv_as != x; then
+    $as_echo "$conftest_s" > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --gdwarf-4 -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	      if test x$gcc_cv_readelf != x \
+	 && $gcc_cv_readelf -w conftest.o 2>&1 \
+		| grep conftest.s > /dev/null 2>&1; then
+	gcc_cv_as_working_gdwarf_n_flag=no
+      else
+	gcc_cv_as_working_gdwarf_n_flag=yes
+      fi
+          else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_working_gdwarf_n_flag" >&5
+$as_echo "$gcc_cv_as_working_gdwarf_n_flag" >&6; }
+
+
+   if test $gcc_cv_as_working_gdwarf_n_flag = yes; then
+
+$as_echo "#define HAVE_AS_WORKING_DWARF_N_FLAG 1" >>confdefs.h
+
+   fi
+ fi
+
  { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for --gstabs option" >&5
 $as_echo_n "checking assembler for --gstabs option... " >&6; }
 if ${gcc_cv_as_gstabs_flag+:} false; then :
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 26a5d8e3619..9154a5475dc 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -5364,7 +5364,7 @@  foo:
      gcc_GAS_CHECK_FEATURE([assembly of compiler generated 32-bit .debug_line],
       gcc_cv_as_debug_line_32_flag,
       [elf,2,36,0], [], [$conftest_s],,
-      [success=yes])
+      [dwarf4_success=yes])
    else
      gcc_GAS_CHECK_FEATURE([assembly of compiler generated 64-bit .debug_line],
       gcc_cv_as_debug_line_64_flag,
@@ -5372,11 +5372,11 @@  foo:
       [dwarf4_success=yes])
    fi
    if test $dwarf4_success = yes; then
+     dwarf4_success=no
      gcc_GAS_CHECK_FEATURE([--gdwarf-4 not refusing compiler generated .debug_line],
       gcc_cv_as_dwarf_4_debug_line_flag,
       [elf,2,36,0], [--gdwarf-4], [$conftest_s],,
-      [AC_DEFINE(HAVE_AS_WORKING_DWARF_4_FLAG, 1,
-[Define if your assembler supports --gdwarf-4 even with compiler generated .debug_line])])
+      [dwarf4_success=yes])
      break
    fi
    dwarf4_debug_info_size=0x36
@@ -5385,6 +5385,59 @@  foo:
    dwarf4_line_sz=5
  done
 
+ if test $dwarf4_success = yes; then
+   conftest_s="\
+	.file	\"foo.c\"
+	.text
+bar:
+#APP
+# 82 \"xxx.h\" 1
+	$insn
+# 0 \"\" 2
+#NO_APP
+	$insn
+foo:
+	.file 1 \"foo.c\"
+	$insn
+	.file 2 \"foo.h\"
+	ret
+"
+   dwarf4_success=no
+   gcc_GAS_CHECK_FEATURE([--gdwarf-4 with the APP marker],
+     gcc_cv_as_dwarf_4_app_flag,,
+     [--gdwarf-4], [$conftest_s],, [dwarf4_success=yes])
+ fi
+
+ if test $dwarf4_success = yes; then
+   conftest_s="\
+	.text
+	.globl	foo
+	.type	foo, %function
+foo:
+	$insn
+	.size	foo, .-foo
+	.file	1 \"foo.c\"
+"
+   gcc_GAS_CHECK_FEATURE([working --gdwarf-4/--gdwarf-5 for all sources],
+     gcc_cv_as_working_gdwarf_n_flag,,
+     [--gdwarf-4],
+     [$conftest_s],
+     [changequote(,)dnl
+      if test x$gcc_cv_readelf != x \
+	 && $gcc_cv_readelf -w conftest.o 2>&1 \
+		| grep conftest.s > /dev/null 2>&1; then
+	gcc_cv_as_working_gdwarf_n_flag=no
+      else
+	gcc_cv_as_working_gdwarf_n_flag=yes
+      fi
+      changequote([,])dnl])
+   if test $gcc_cv_as_working_gdwarf_n_flag = yes; then
+     AC_DEFINE(HAVE_AS_WORKING_DWARF_N_FLAG, 1,
+[Define if your assembler supports --gdwarf-4/--gdwarf-5 even with
+ compiler generated .debug_line.])
+   fi
+ fi
+
  gcc_GAS_CHECK_FEATURE([--gstabs option],
   gcc_cv_as_gstabs_flag,
   [elf,2,11,0], [--gstabs], [$insn],,
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index ba93a6c3d81..534877babfb 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -11884,7 +11884,7 @@  asm_outputs_debug_line_str (void)
     return true;
   else
     {
-#if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_4_FLAG)
+#if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_N_FLAG)
       return !dwarf_split_debug_info && dwarf_version >= 5;
 #else
       return false;
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 337c27442a3..cdf4d4f2403 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -880,7 +880,7 @@  proper position among the other output files.  */
 /* Define ASM_DEBUG_SPEC to be a spec suitable for translating '-g'
    to the assembler, when compiling assembly sources only.  */
 #ifndef ASM_DEBUG_SPEC
-# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_4_FLAG)
+# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_N_FLAG)
 /* If --gdwarf-N is supported and as can handle even compiler generated
    .debug_line with it, supply --gdwarf-N in ASM_DEBUG_OPTION_SPEC rather
    than in ASM_DEBUG_SPEC, so that it applies to both .s and .c etc.
@@ -921,7 +921,7 @@  proper position among the other output files.  */
 /* Define ASM_DEBUG_OPTION_SPEC to be a spec suitable for translating '-g'
    to the assembler when compiling all sources.  */
 #ifndef ASM_DEBUG_OPTION_SPEC
-# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_4_FLAG)
+# if defined(HAVE_AS_GDWARF_5_DEBUG_FLAG) && defined(HAVE_AS_WORKING_DWARF_N_FLAG)
 #  define ASM_DEBUG_OPTION_DWARF_OPT					\
 	"%{%:dwarf-version-gt(4):--gdwarf-5 ;"				\
 	"%:dwarf-version-gt(3):--gdwarf-4 ;"				\
-- 
2.26.2