Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Nick Clifton]

Hi Jozef,
   
> Attached patch with the string wrapped in G_().

When I applied this patch to the sources and ran the new test, I encountered
an internal compiler error:

 msp430-elf/gcc/xgcc [...] pr78818-auto-warn.c [...]
 [...]
 gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c: In function 'main':

 gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c:10:3: internal compiler error: in get, at cgraph.h:403

  0xd30d3b symtab_node::get(tree_node const*)
	gcc/current/gcc/cgraph.h:400

  0xd30d3b decl_section_name(tree_node const*)
	gcc/current/gcc/tree.c:700

  0xd9ff22 msp430_data_attr
                     gcc/current/gcc/config/msp430/msp430.c:1998


 It seems that there is a problem with calling the DECL_SECTION_NAME macro on the
 line just before your new code.  Are you able to reproduce this problem ?

Cheers
  Nick

  

Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Jozef Lawrynowicz]

[-- Attachment #1: Type: text/plain, Size: 1824 bytes --]

On 30/05/2017 12:50, Nick Clifton wrote:
> When I applied this patch to the sources and ran the new test, I encountered
> an internal compiler error:
> 
>   msp430-elf/gcc/xgcc [...] pr78818-auto-warn.c [...]
>   [...]
>   gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c: In function 'main':
> 
>   gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c:10:3: internal compiler error: in get, at cgraph.h:403
> 
>    0xd30d3b symtab_node::get(tree_node const*)
> 	gcc/current/gcc/cgraph.h:400
> 
>    0xd30d3b decl_section_name(tree_node const*)
> 	gcc/current/gcc/tree.c:700
> 
>    0xd9ff22 msp430_data_attr
>                       gcc/current/gcc/config/msp430/msp430.c:1998
> 
> 
>   It seems that there is a problem with calling the DECL_SECTION_NAME macro on the
>   line just before your new code.  Are you able to reproduce this problem ?
> 

Hi Nick,

Apologies for the delay in replying.
I have reproduced this issue with current trunk and on the gcc-7-branch,
but it does not reproduce on the gcc-6-branch.

The ICE isn't caused by my patch but the pr78818-auto-warn.c test does
expose it.

I've attached an additional patch to fix the ICE (0001*). The ICE was
caused by a new gcc_checking_assert added in GCC7 that checks that
"symtab_node" has been called on a sane object. Added some additional
check in msp430.c:data_attr that prevent section names being looked up
on variables that can't have a section.

The 0002* patch has been updated as this also caused an ICE when running
the test case for the same reason as above, which was exposed when the
first ICE was fixed.

I have tested these patches on trunk this time (previous testing was
done on performed on gcc-6-branch only) and can confirm there are no
regressions and the new tests build successfully.

Ok for trunk and gcc-7-branch?

Thanks,
Jozef


[-- Attachment #2: 0001-MSP430-Check-if-a-variable-can-have-a-section-before.patch --]
[-- Type: text/plain, Size: 1449 bytes --]

From 8a41a45f2f771ae540b16ec007ded499a9ed5244 Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Mon, 5 Jun 2017 18:07:22 +0000
Subject: [PATCH 1/3] MSP430: Check if a variable can have a section before
 checking for a section name

2017-06-XX	Jozef Lawrynowicz	<jozef.l@somniumtech.com>

	gcc/
	* config/msp430/msp430.c (msp430_data_attr): Check that it's possible
	for a variable to have a section before checking if the section has a
	name.
---
 gcc/config/msp430/msp430.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index dd53dea..cdd765b 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -1995,8 +1995,10 @@ msp430_data_attr (tree * node,
   if (TREE_CODE (* node) != VAR_DECL)
     message = "%qE attribute only applies to variables";
 
-  if (DECL_SECTION_NAME (* node))
-    message = "%qE attribute cannot be applied to variables with specific sections";
+  /* Check that it's possible for the variable to have a section.  */
+  if ((TREE_STATIC (* node) || DECL_EXTERNAL (* node) || in_lto_p)
+      && DECL_SECTION_NAME (* node))
+      message = "%qE attribute cannot be applied to variables with specific sections";
 
   /* If this var is thought to be common, then change this.  Common variables
      are assigned to sections before the backend has a chance to process them.  */
-- 
1.8.3.1


[-- Attachment #3: 0002-MSP430-Fix-persistent-attribute-not-placing-data-int.patch --]
[-- Type: text/plain, Size: 4952 bytes --]

From e9404da28ade51c0303394f6ab12528b1c62afca Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Fri, 12 May 2017 13:04:59 +0000
Subject: [PATCH 2/3] MSP430: Fix persistent attribute not placing data into
 the .persistent section

2017-06-XX	Jozef Lawrynowicz	<jozef.l@somniumtech.com>

	gcc/
	PR target/78818
	* config/msp430/msp430.c (msp430_unique_section): Set section to
	.persistent if persistent attribute is set.

	gcc/testsuite
	PR target/78818
	* gcc.target/msp430/msp430.exp: Search for tests in subfolders as well as
	main directory.
	* gcc.target/msp430/pr78818/pr78818-real.c: New template for tests.
	* gcc.target/msp430/pr78818/pr78818-auto.c: New test.
	* gcc.target/msp430/pr78818/pr78818-data-region.c: New test.
	* gcc.target/msp430/pr78818/pr78818-data-sec.c: Likewise.
---
 gcc/config/msp430/msp430.c                                    | 8 ++++++++
 gcc/testsuite/gcc.target/msp430/msp430.exp                    | 4 ++--
 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto.c        | 5 +++++
 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-region.c | 7 +++++++
 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-sec.c    | 8 ++++++++
 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-real.c        | 9 +++++++++
 6 files changed, 39 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto.c
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-region.c
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-sec.c
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-real.c

diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index cdd765b..c359c77 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -2000,6 +2000,14 @@ msp430_data_attr (tree * node,
       && DECL_SECTION_NAME (* node))
       message = "%qE attribute cannot be applied to variables with specific sections";
 
+  /* It's not clear if there is anything that can be set here to prevent the
+   * front end placing the variable before the back end can handle it, in a
+   * similar way to how DECL_COMMON is used below.
+   * So just place the variable in the .persistent section now.  */
+  if ((TREE_STATIC (* node) || DECL_EXTERNAL (* node) || in_lto_p)
+      && TREE_NAME_EQ (name, ATTR_PERSIST))
+    set_decl_section_name (* node, ".persistent");
+
   /* If this var is thought to be common, then change this.  Common variables
      are assigned to sections before the backend has a chance to process them.  */
   if (DECL_COMMON (* node))
diff --git a/gcc/testsuite/gcc.target/msp430/msp430.exp b/gcc/testsuite/gcc.target/msp430/msp430.exp
index e54d531..a056417 100644
--- a/gcc/testsuite/gcc.target/msp430/msp430.exp
+++ b/gcc/testsuite/gcc.target/msp430/msp430.exp
@@ -34,8 +34,8 @@ if ![info exists DEFAULT_CFLAGS] then {
 dg-init
 
 # Main loop.
-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cCS\]]] \
-	"" $DEFAULT_CFLAGS
+dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/{*,*/*}.\[cCS\]]] \
+  "" $DEFAULT_CFLAGS
 
 # All done.
 dg-finish
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto.c b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto.c
new file mode 100644
index 0000000..1fb0b28
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto.c
@@ -0,0 +1,5 @@
+/* { dg-do compile } */
+
+/* { dg-final { scan-assembler-not "\\.comm" } } */
+
+#include "pr78818-real.c"
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-region.c b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-region.c
new file mode 100644
index 0000000..5da6a82
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-region.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+
+/* { dg-options "-mdata-region=either" } */
+
+/* { dg-final { scan-assembler-not "\\.either" } } */
+
+#include "pr78818-real.c"
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-sec.c b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-sec.c
new file mode 100644
index 0000000..2d40ea7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-data-sec.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+
+/* { dg-options "-fdata-sections" } */
+
+/* { dg-final { scan-assembler-not "\\.data" } } */
+/* { dg-final { scan-assembler-not "\\.bss" } } */
+
+#include "pr78818-real.c"
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-real.c b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-real.c
new file mode 100644
index 0000000..504ed4a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-real.c
@@ -0,0 +1,9 @@
+__attribute__((persistent)) int persistent_1 = 1;
+__attribute__((persistent)) int persistent_2 = 0;
+static __attribute__((persistent)) int persistent_3 = 1;
+static __attribute__((persistent)) int persistent_4 = 0;
+
+int main (void)
+{
+  return 0;
+}
-- 
1.8.3.1


[-- Attachment #4: 0003-MSP430-Emit-warning-when-persistent-attribute-is-use.patch --]
[-- Type: text/plain, Size: 2685 bytes --]

From 0edf1ea2774381eeaac395d1b010aae03ec98418 Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Fri, 5 May 2017 15:31:39 +0000
Subject: [PATCH 3/3] MSP430: Emit warning when persistent attribute is used on
 an automatic variable

2017-06-XX	Jozef Lawrynowicz	<jozef.l@somniumtech.com>

	gcc/
	PR target/78818
	* config/msp430/msp430.c (msp430_unique_section): Warn if .persistent
	attribute is used on an automatic variable.

	gcc/testsuite
	PR target/78818
	* gcc.target/msp430/pr78818/pr78818-auto-warn.c: New test.
---
 gcc/config/msp430/msp430.c                                |  5 +++++
 .../gcc.target/msp430/pr78818/pr78818-auto-warn.c         | 15 +++++++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c

diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index c359c77..dfd2af6 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -40,6 +40,7 @@
 #include "expr.h"
 #include "langhooks.h"
 #include "builtins.h"
+#include "intl.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -2000,6 +2001,10 @@ msp430_data_attr (tree * node,
       && DECL_SECTION_NAME (* node))
       message = "%qE attribute cannot be applied to variables with specific sections";
 
+  if (!message && TREE_NAME_EQ (name, ATTR_PERSIST) && !TREE_STATIC (* node)
+      && !TREE_PUBLIC (* node) && !DECL_EXTERNAL (* node))
+    message = G_("%qE attribute has no effect on automatic variables");
+
   /* It's not clear if there is anything that can be set here to prevent the
    * front end placing the variable before the back end can handle it, in a
    * similar way to how DECL_COMMON is used below.
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c
new file mode 100644
index 0000000..1d92fe1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+__attribute__((persistent)) int persistent_1_g = 1;
+__attribute__((persistent)) int persistent_2_g = 0;
+static __attribute__((persistent)) int persistent_3_g = 1;
+static __attribute__((persistent)) int persistent_4_g = 0;
+
+int main (void)
+{
+  __attribute__((persistent)) int persistent_1 = 1; /* { dg-warning "attribute has no effect on automatic" } */
+  __attribute__((persistent)) int persistent_2 = 0; /* { dg-warning "attribute has no effect on automatic" } */
+  static __attribute__((persistent)) int persistent_3 = 1;
+  static __attribute__((persistent)) int persistent_4 = 0;
+  return 0;
+}
-- 
1.8.3.1

Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Nick Clifton]

Hi Jozef,

> Ok for trunk and gcc-7-branch?

Approved - please apply (to both).

Cheers
  Nick

Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Jozef Lawrynowicz]

On 13/06/2017 16:54, Nick Clifton wrote:
> Hi Jozef,
> 
>> Ok for trunk and gcc-7-branch?
> 
> Approved - please apply (to both).
> 
> Cheers
>    Nick
> 
> 

Sorry, didn't mention in that last post that I don't have write access,
could someone please apply this for me.

Thanks,
Jozef

Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Nick Clifton]

Hi Jozef,

> Sorry, didn't mention in that last post that I don't have write access,
> could someone please apply this for me.

Applied.  Sorry about the delay (again).

Cheers
  Nick

Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Jozef Lawrynowicz]

[-- Attachment #1: Type: text/plain, Size: 666 bytes --]

On 18 May 2017 at 16:46, Martin Sebor <msebor@gmail.com> wrote:
> +  if (!message && TREE_NAME_EQ (name, ATTR_PERSIST) && !TREE_STATIC (*
> node)
> +      && !TREE_PUBLIC (* node) && !DECL_EXTERNAL (* node))
> +    message = "%qE attribute has no effect on automatic variables";
>
> In code like this (both existing and new) where the format string
> is being assigned to a pointer that is then passed to one of the
> diagnostic functions, I believe the string literal needs to wrapped
> in G_() so that it can be translated.

Attached patch with the string wrapped in G_().

I'll update the other diagnostic strings without G_() in a separate patch.

Thanks,
Jozef

[-- Attachment #2: 0002-MSP430-Emit-warning-when-persistent-attribute-is-use.patch --]
[-- Type: application/octet-stream, Size: 2681 bytes --]

From 4790629950819460a22738da88b01c104012d98e Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Fri, 5 May 2017 15:31:39 +0000
Subject: [PATCH 2/2] MSP430: Emit warning when persistent attribute is used on
 an automatic variable

2017-05-XX	Jozef Lawrynowicz	<jozef.l@somniumtech.com>
	
	gcc/
	PR target/78818
	* config/msp430/msp430.c (msp430_unique_section): Warn if .persistent
	attribute is used on an automatic variable.

	gcc/testsuite
	PR target/78818
	* gcc.target/msp430/pr78818/pr78818-auto-warn.c: New test.
---
 gcc/config/msp430/msp430.c                                |  5 +++++
 .../gcc.target/msp430/pr78818/pr78818-auto-warn.c         | 15 +++++++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c

diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index c70121e..959f235 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -39,6 +39,7 @@
 #include "expr.h"
 #include "langhooks.h"
 #include "builtins.h"
+#include "intl.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -1975,6 +1976,10 @@ msp430_data_attr (tree * node,
   if (DECL_SECTION_NAME (* node))
     message = "%qE attribute cannot be applied to variables with specific sections";
 
+  if (!message && TREE_NAME_EQ (name, ATTR_PERSIST) && !TREE_STATIC (* node)
+      && !TREE_PUBLIC (* node) && !DECL_EXTERNAL (* node))
+    message = G_("%qE attribute has no effect on automatic variables");
+
   /* It's not clear if there is anything that can be set here to prevent the
    * front end placing the variable before the back end can handle it, in a
    * similar way to how DECL_COMMON is used below.
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c
new file mode 100644
index 0000000..1d92fe1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+__attribute__((persistent)) int persistent_1_g = 1;
+__attribute__((persistent)) int persistent_2_g = 0;
+static __attribute__((persistent)) int persistent_3_g = 1;
+static __attribute__((persistent)) int persistent_4_g = 0;
+
+int main (void)
+{
+  __attribute__((persistent)) int persistent_1 = 1; /* { dg-warning "attribute has no effect on automatic" } */
+  __attribute__((persistent)) int persistent_2 = 0; /* { dg-warning "attribute has no effect on automatic" } */
+  static __attribute__((persistent)) int persistent_3 = 1;
+  static __attribute__((persistent)) int persistent_4 = 0;
+  return 0;
+}
-- 
1.8.3.1

Re: [PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Martin Sebor]

On 05/17/2017 09:45 AM, Jozef Lawrynowicz wrote:
> Add warning to back end and add test.
>
> Patch is attached.
>
> If the patch is acceptable, I would appreciate if someone could commit
> it for me as I do not have write access.
>
> 2017-05-XX Jozef Lawrynowicz <jozef.l@somniumtech.com>
>     gcc/
>     PR target/78818
>     * config/msp430/msp430.c (msp430_unique_section): Warn if .persistent
>     attribute is used on an automatic variable.

+  if (!message && TREE_NAME_EQ (name, ATTR_PERSIST) && !TREE_STATIC (* 
node)
+      && !TREE_PUBLIC (* node) && !DECL_EXTERNAL (* node))
+    message = "%qE attribute has no effect on automatic variables";

In code like this (both existing and new) where the format string
is being assigned to a pointer that is then passed to one of the
diagnostic functions, I believe the string literal needs to wrapped
in G_() so that it can be translated.

Martin

[PATCH 2/2] [MSP430] Fix issues handling .persistent attribute (PR 78818)

[Jozef Lawrynowicz]

[-- Attachment #1: Type: text/plain, Size: 480 bytes --]

Add warning to back end and add test.

Patch is attached.

If the patch is acceptable, I would appreciate if someone could commit
it for me as I do not have write access.

2017-05-XX Jozef Lawrynowicz <jozef.l@somniumtech.com>
    gcc/
    PR target/78818
    * config/msp430/msp430.c (msp430_unique_section): Warn if .persistent
    attribute is used on an automatic variable.

    gcc/testsuite
    PR target/78818
    * gcc.target/msp430/pr78818/pr78818-auto-warn.c: New test.

[-- Attachment #2: 0002-MSP430-Emit-warning-when-persistent-attribute-is-use.patch --]
[-- Type: application/octet-stream, Size: 2503 bytes --]

From 24726c1e0d68eebeaed6bf5f3fd3f39b00a93a7e Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Fri, 5 May 2017 15:31:39 +0000
Subject: [PATCH 2/2] MSP430: Emit warning when persistent attribute is used on
 an automatic variable

2017-05-XX	Jozef Lawrynowicz	<jozef.l@somniumtech.com>
	
	gcc/
	PR target/78818
	* config/msp430/msp430.c (msp430_unique_section): Warn if .persistent
	attribute is used on an automatic variable.

	gcc/testsuite
	PR target/78818
	* gcc.target/msp430/pr78818/pr78818-auto-warn.c: New test.
---
 gcc/config/msp430/msp430.c                                |  4 ++++
 .../gcc.target/msp430/pr78818/pr78818-auto-warn.c         | 15 +++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c

diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index c70121e..9c3720d 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -1975,6 +1975,10 @@ msp430_data_attr (tree * node,
   if (DECL_SECTION_NAME (* node))
     message = "%qE attribute cannot be applied to variables with specific sections";
 
+  if (!message && TREE_NAME_EQ (name, ATTR_PERSIST) && !TREE_STATIC (* node)
+      && !TREE_PUBLIC (* node) && !DECL_EXTERNAL (* node))
+    message = "%qE attribute has no effect on automatic variables";
+
   /* It's not clear if there is anything that can be set here to prevent the
    * front end placing the variable before the back end can handle it, in a
    * similar way to how DECL_COMMON is used below.
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c
new file mode 100644
index 0000000..1d92fe1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr78818/pr78818-auto-warn.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+__attribute__((persistent)) int persistent_1_g = 1;
+__attribute__((persistent)) int persistent_2_g = 0;
+static __attribute__((persistent)) int persistent_3_g = 1;
+static __attribute__((persistent)) int persistent_4_g = 0;
+
+int main (void)
+{
+  __attribute__((persistent)) int persistent_1 = 1; /* { dg-warning "attribute has no effect on automatic" } */
+  __attribute__((persistent)) int persistent_2 = 0; /* { dg-warning "attribute has no effect on automatic" } */
+  static __attribute__((persistent)) int persistent_3 = 1;
+  static __attribute__((persistent)) int persistent_4 = 0;
+  return 0;
+}
-- 
1.8.3.1