Fix false -Wodr warnings

Fix false -Wodr warnings

[Jan Hubicka]

Hi,
this patch fixes false warning that is output when different -std
settings are used. In this case C++ FE produces same declaration in
different representations which differ by 0 sized fileds only.
The patch makes them to be ignored (and I checked we ignore them for
canonical type merging too)

Bootstrapped/regtested x86_64-linux, comitted.

Honza

	PR lto/89358
	* g++.dg/lto/pr89358_0.C: New testcase.
	* g++.dg/lto/pr89358_1.C: New testcase.
	* ipa-devirt.c (skip_in_fields_list_p): New.
	(odr_types_equivalent_p): Use it.
Index: testsuite/g++.dg/lto/pr89358_0.C
===================================================================
--- testsuite/g++.dg/lto/pr89358_0.C	(nonexistent)
+++ testsuite/g++.dg/lto/pr89358_0.C	(working copy)
@@ -0,0 +1,11 @@
+/* { dg-do link } */
+/* { dg-options "-std=c++17"  } */
+#include <map>
+
+extern void test();
+
+int main()
+{
+        std::map<int, int> m;
+        test();
+}
Index: testsuite/g++.dg/lto/pr89358_1.C
===================================================================
--- testsuite/g++.dg/lto/pr89358_1.C	(nonexistent)
+++ testsuite/g++.dg/lto/pr89358_1.C	(working copy)
@@ -0,0 +1,7 @@
+/* { dg-options "-std=c++14"  } */
+#include <map>
+
+void test()
+{
+        std::map<int, int> m;
+}
Index: ipa-devirt.c
===================================================================
--- ipa-devirt.c	(revision 270324)
+++ ipa-devirt.c	(working copy)
@@ -1282,6 +1282,24 @@ warn_types_mismatch (tree t1, tree t2, l
     inform (loc_t2, "the incompatible type is defined here");
 }
 
+/* Return true if T should be ignored in TYPE_FIELDS for ODR comparsion.  */
+
+static bool
+skip_in_fields_list_p (tree t)
+{
+  if (TREE_CODE (t) != FIELD_DECL)
+    return true;
+  /* C++ FE introduces zero sized fields depending on -std setting, see
+     PR89358.  */
+  if (DECL_SIZE (t)
+      && integer_zerop (DECL_SIZE (t))
+      && DECL_ARTIFICIAL (t)
+      && DECL_IGNORED_P (t)
+      && !DECL_NAME (t))
+    return true;
+  return false;
+}
+
 /* Compare T1 and T2, report ODR violations if WARN is true and set
    WARNED to true if anything is reported.  Return true if types match.
    If true is returned, the types are also compatible in the sense of
@@ -1548,9 +1566,9 @@ odr_types_equivalent_p (tree t1, tree t2
 		 f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2))
 	      {
 		/* Skip non-fields.  */
-		while (f1 && TREE_CODE (f1) != FIELD_DECL)
+		while (f1 && skip_in_fields_list_p (f1))
 		  f1 = TREE_CHAIN (f1);
-		while (f2 && TREE_CODE (f2) != FIELD_DECL)
+		while (f2 && skip_in_fields_list_p (f2))
 		  f2 = TREE_CHAIN (f2);
 		if (!f1 || !f2)
 		  break;

Re: Fix false -Wodr warnings

[Richard Biener]

On Sun, Apr 14, 2019 at 10:59 PM Jan Hubicka <hubicka@ucw.cz> wrote:
>
> Hi,
> this patch fixes false warning that is output when different -std
> settings are used. In this case C++ FE produces same declaration in
> different representations which differ by 0 sized fileds only.
> The patch makes them to be ignored (and I checked we ignore them for
> canonical type merging too)
>
> Bootstrapped/regtested x86_64-linux, comitted.

The testcase is bogus

WARNING: lto.exp does not support dg-do
WARNING: lto.exp does not support dg-options in primary source file


> Honza
>
>         PR lto/89358
>         * g++.dg/lto/pr89358_0.C: New testcase.
>         * g++.dg/lto/pr89358_1.C: New testcase.
>         * ipa-devirt.c (skip_in_fields_list_p): New.
>         (odr_types_equivalent_p): Use it.
> Index: testsuite/g++.dg/lto/pr89358_0.C
> ===================================================================
> --- testsuite/g++.dg/lto/pr89358_0.C    (nonexistent)
> +++ testsuite/g++.dg/lto/pr89358_0.C    (working copy)
> @@ -0,0 +1,11 @@
> +/* { dg-do link } */
> +/* { dg-options "-std=c++17"  } */
> +#include <map>
> +
> +extern void test();
> +
> +int main()
> +{
> +        std::map<int, int> m;
> +        test();
> +}
> Index: testsuite/g++.dg/lto/pr89358_1.C
> ===================================================================
> --- testsuite/g++.dg/lto/pr89358_1.C    (nonexistent)
> +++ testsuite/g++.dg/lto/pr89358_1.C    (working copy)
> @@ -0,0 +1,7 @@
> +/* { dg-options "-std=c++14"  } */
> +#include <map>
> +
> +void test()
> +{
> +        std::map<int, int> m;
> +}
> Index: ipa-devirt.c
> ===================================================================
> --- ipa-devirt.c        (revision 270324)
> +++ ipa-devirt.c        (working copy)
> @@ -1282,6 +1282,24 @@ warn_types_mismatch (tree t1, tree t2, l
>      inform (loc_t2, "the incompatible type is defined here");
>  }
>
> +/* Return true if T should be ignored in TYPE_FIELDS for ODR comparsion.  */
> +
> +static bool
> +skip_in_fields_list_p (tree t)
> +{
> +  if (TREE_CODE (t) != FIELD_DECL)
> +    return true;
> +  /* C++ FE introduces zero sized fields depending on -std setting, see
> +     PR89358.  */
> +  if (DECL_SIZE (t)
> +      && integer_zerop (DECL_SIZE (t))
> +      && DECL_ARTIFICIAL (t)
> +      && DECL_IGNORED_P (t)
> +      && !DECL_NAME (t))
> +    return true;
> +  return false;
> +}
> +
>  /* Compare T1 and T2, report ODR violations if WARN is true and set
>     WARNED to true if anything is reported.  Return true if types match.
>     If true is returned, the types are also compatible in the sense of
> @@ -1548,9 +1566,9 @@ odr_types_equivalent_p (tree t1, tree t2
>                  f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2))
>               {
>                 /* Skip non-fields.  */
> -               while (f1 && TREE_CODE (f1) != FIELD_DECL)
> +               while (f1 && skip_in_fields_list_p (f1))
>                   f1 = TREE_CHAIN (f1);
> -               while (f2 && TREE_CODE (f2) != FIELD_DECL)
> +               while (f2 && skip_in_fields_list_p (f2))
>                   f2 = TREE_CHAIN (f2);
>                 if (!f1 || !f2)
>                   break;

Re: Fix false -Wodr warnings

[Dominique d'Humières]

Hi Jan,

The test causes

WARNING: lto.exp does not support dg-do
WARNING: lto.exp does not support dg-options in primary source file

This is fixed by the following patch

--- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-15 00:04:48.000000000 +0200
+++ gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-16 13:13:14.000000000 +0200
@@ -1,5 +1,5 @@
-/* { dg-do link } */
-/* { dg-options "-std=c++17"  } */
+/* { dg-lto-do link } */
+/* { dg-lto-options "-std=c++17"  } */
 #include <map>
 
 extern void test();
--- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_1.C	2019-04-15 00:04:48.000000000 +0200
+++ gcc/testsuite/g++.dg/lto/pr89358_1.C	2019-04-16 13:14:44.000000000 +0200
@@ -1,4 +1,3 @@
-/* { dg-options "-std=c++14"  } */
 #include <map>
 
 void test()

TIA

Dominique

Re: Fix false -Wodr warnings

[Jan Hubicka]

> Hi Jan,
> 
> The test causes
> 
> WARNING: lto.exp does not support dg-do
> WARNING: lto.exp does not support dg-options in primary source file
> 
> This is fixed by the following patch
> 
> --- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-15 00:04:48.000000000 +0200
> +++ gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-16 13:13:14.000000000 +0200
> @@ -1,5 +1,5 @@
> -/* { dg-do link } */
> -/* { dg-options "-std=c++17"  } */
> +/* { dg-lto-do link } */
> +/* { dg-lto-options "-std=c++17"  } */

Thanks, this changle is OK.
Honza
>  #include <map>
>  
>  extern void test();
> --- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_1.C	2019-04-15 00:04:48.000000000 +0200
> +++ gcc/testsuite/g++.dg/lto/pr89358_1.C	2019-04-16 13:14:44.000000000 +0200
> @@ -1,4 +1,3 @@
> -/* { dg-options "-std=c++14"  } */
>  #include <map>
>  
>  void test()
> 
> TIA
> 
> Dominique

Re: Fix false -Wodr warnings

[Richard Biener]

On Tue, Apr 16, 2019 at 2:51 PM Jan Hubicka <hubicka@ucw.cz> wrote:
>
> > Hi Jan,
> >
> > The test causes
> >
> > WARNING: lto.exp does not support dg-do
> > WARNING: lto.exp does not support dg-options in primary source file
> >
> > This is fixed by the following patch
> >
> > --- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_0.C    2019-04-15 00:04:48.000000000 +0200
> > +++ gcc/testsuite/g++.dg/lto/pr89358_0.C      2019-04-16 13:13:14.000000000 +0200
> > @@ -1,5 +1,5 @@
> > -/* { dg-do link } */
> > -/* { dg-options "-std=c++17"  } */
> > +/* { dg-lto-do link } */
> > +/* { dg-lto-options "-std=c++17"  } */
>
> Thanks, this changle is OK.
> Honza
> >  #include <map>
> >
> >  extern void test();
> > --- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_1.C    2019-04-15 00:04:48.000000000 +0200
> > +++ gcc/testsuite/g++.dg/lto/pr89358_1.C      2019-04-16 13:14:44.000000000 +0200
> > @@ -1,4 +1,3 @@
> > -/* { dg-options "-std=c++14"  } */

But you should leave this one in place, otherwise it will no longer
test what it was supposed to test.

Richard.

> >  #include <map>
> >
> >  void test()
> >
> > TIA
> >
> > Dominique

Re: Fix false -Wodr warnings

[Jakub Jelinek]

On Tue, Apr 16, 2019 at 02:51:14PM +0200, Jan Hubicka wrote:
> > Hi Jan,
> > 
> > The test causes
> > 
> > WARNING: lto.exp does not support dg-do
> > WARNING: lto.exp does not support dg-options in primary source file
> > 
> > This is fixed by the following patch
> > 
> > --- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-15 00:04:48.000000000 +0200
> > +++ gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-16 13:13:14.000000000 +0200
> > @@ -1,5 +1,5 @@
> > -/* { dg-do link } */
> > -/* { dg-options "-std=c++17"  } */
> > +/* { dg-lto-do link } */
> > +/* { dg-lto-options "-std=c++17"  } */
> 
> Thanks, this changle is OK.
> Honza
> >  #include <map>
> >  
> >  extern void test();
> > --- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_1.C	2019-04-15 00:04:48.000000000 +0200
> > +++ gcc/testsuite/g++.dg/lto/pr89358_1.C	2019-04-16 13:14:44.000000000 +0200
> > @@ -1,4 +1,3 @@
> > -/* { dg-options "-std=c++14"  } */

But this change is not ok and makes the test useless.
The whole point of the test is to test if compiling one TU with -std=c++17
and another one with -std=c++14 and linking them together doesn't produce
warnings.  I think dg-options in *_1.C is ok, several tests have those:
20100302_1.C:// { dg-options "-fabi-version=0" }
pr60150_1.C:// { dg-options "-fno-lto" }
pr63270_2.C:// { dg-options "-fno-lto" }
pr64076_1.C:// { dg-options -fno-lto }
pr65276_1.C:// { dg-options "-O2" }
pr68811_1.C:// { dg-options "-O2 -flto -w" }

	Jakub

Re: Fix false -Wodr warnings

[Dominique d'Humières]

> Le 16 avr. 2019 à 15:07, Jakub Jelinek <jakub@redhat.com> a écrit :
> 
> On Tue, Apr 16, 2019 at 02:51:14PM +0200, Jan Hubicka wrote:
>>> Hi Jan,
>>> 
>>> The test causes
>>> 
>>> WARNING: lto.exp does not support dg-do
>>> WARNING: lto.exp does not support dg-options in primary source file
>>> 
>>> This is fixed by the following patch
>>> 
>>> --- ../_clean/gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-15 00:04:48.000000000 +0200
>>> +++ gcc/testsuite/g++.dg/lto/pr89358_0.C	2019-04-16 13:13:14.000000000 +0200
>>> @@ -1,5 +1,5 @@
>>> -/* { dg-do link } */
>>> -/* { dg-options "-std=c++17"  } */
>>> +/* { dg-lto-do link } */
>>> +/* { dg-lto-options "-std=c++17"  } */
>> 
>> Thanks, this changle is OK.
>> Honza

Committed as revision r270390

Dominique

Re: Fix false -Wodr warnings

[Thomas Schwinge]

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Hi!

On 2019-04-15T13:55:39+0200, Richard Biener <richard.guenther@gmail.com> wrote:
> On Sun, Apr 14, 2019 at 10:59 PM Jan Hubicka <hubicka@ucw.cz> wrote:
>> this patch fixes false warning that is output when different -std
>> settings are used. In this case C++ FE produces same declaration in
>> different representations which differ by 0 sized fileds only.
>> The patch makes them to be ignored (and I checked we ignore them for
>> canonical type merging too)
>>
>> Bootstrapped/regtested x86_64-linux, comitted.

In 13ef7dc2448c0f9d8981577bb5448ee9b6842b1c "Backport
d2a0371d2641e85c5e6ca396029be32204d976df", Martin backported this to
releases/gcc-8, but without including the fix-up for...

> The testcase is bogus
>
> WARNING: lto.exp does not support dg-do
> WARNING: lto.exp does not support dg-options in primary source file

... that one.  As obvious, pushed Dominique's trunk r270390/commit
ef9387d8fe79219a106c3f9d6c6a87b0a9065d54 to releases/gcc-8 in
8e55f241ab8c754a2ab8ec2fe39afd9173589401 "pr89358_0.C: Replace dg-* with
dg-lto-*.", see attached.


Grüße
 Thomas


>>         PR lto/89358
>>         * g++.dg/lto/pr89358_0.C: New testcase.
>>         * g++.dg/lto/pr89358_1.C: New testcase.
>>         * ipa-devirt.c (skip_in_fields_list_p): New.
>>         (odr_types_equivalent_p): Use it.
>> Index: testsuite/g++.dg/lto/pr89358_0.C
>> ===================================================================
>> --- testsuite/g++.dg/lto/pr89358_0.C    (nonexistent)
>> +++ testsuite/g++.dg/lto/pr89358_0.C    (working copy)
>> @@ -0,0 +1,11 @@
>> +/* { dg-do link } */
>> +/* { dg-options "-std=c++17"  } */
>> +#include <map>
>> +
>> +extern void test();
>> +
>> +int main()
>> +{
>> +        std::map<int, int> m;
>> +        test();
>> +}
>> Index: testsuite/g++.dg/lto/pr89358_1.C
>> ===================================================================
>> --- testsuite/g++.dg/lto/pr89358_1.C    (nonexistent)
>> +++ testsuite/g++.dg/lto/pr89358_1.C    (working copy)
>> @@ -0,0 +1,7 @@
>> +/* { dg-options "-std=c++14"  } */
>> +#include <map>
>> +
>> +void test()
>> +{
>> +        std::map<int, int> m;
>> +}
>> Index: ipa-devirt.c
>> ===================================================================
>> --- ipa-devirt.c        (revision 270324)
>> +++ ipa-devirt.c        (working copy)
>> @@ -1282,6 +1282,24 @@ warn_types_mismatch (tree t1, tree t2, l
>>      inform (loc_t2, "the incompatible type is defined here");
>>  }
>>
>> +/* Return true if T should be ignored in TYPE_FIELDS for ODR comparsion.  */
>> +
>> +static bool
>> +skip_in_fields_list_p (tree t)
>> +{
>> +  if (TREE_CODE (t) != FIELD_DECL)
>> +    return true;
>> +  /* C++ FE introduces zero sized fields depending on -std setting, see
>> +     PR89358.  */
>> +  if (DECL_SIZE (t)
>> +      && integer_zerop (DECL_SIZE (t))
>> +      && DECL_ARTIFICIAL (t)
>> +      && DECL_IGNORED_P (t)
>> +      && !DECL_NAME (t))
>> +    return true;
>> +  return false;
>> +}
>> +
>>  /* Compare T1 and T2, report ODR violations if WARN is true and set
>>     WARNED to true if anything is reported.  Return true if types match.
>>     If true is returned, the types are also compatible in the sense of
>> @@ -1548,9 +1566,9 @@ odr_types_equivalent_p (tree t1, tree t2
>>                  f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2))
>>               {
>>                 /* Skip non-fields.  */
>> -               while (f1 && TREE_CODE (f1) != FIELD_DECL)
>> +               while (f1 && skip_in_fields_list_p (f1))
>>                   f1 = TREE_CHAIN (f1);
>> -               while (f2 && TREE_CODE (f2) != FIELD_DECL)
>> +               while (f2 && skip_in_fields_list_p (f2))
>>                   f2 = TREE_CHAIN (f2);
>>                 if (!f1 || !f2)
>>                   break;



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From 8e55f241ab8c754a2ab8ec2fe39afd9173589401 Mon Sep 17 00:00:00 2001
From: Dominique d'Humieres <dominiq@gcc.gnu.org>
Date: Tue, 16 Apr 2019 15:24:58 +0200
Subject: [PATCH] pr89358_0.C: Replace dg-* with dg-lto-*.

2019-04-16  Dominique d'Humieres  <dominiq@gcc.gnu.org>

	* g++.dg/lto/pr89358_0.C: Replace dg-* with dg-lto-*.

(cherry picked from trunk r270390/commit ef9387d8fe79219a106c3f9d6c6a87b0a9065d54)
---
 gcc/testsuite/ChangeLog              | 7 +++++++
 gcc/testsuite/g++.dg/lto/pr89358_0.C | 4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6c2c5559b9b5..1d0ed10a84ac 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2020-01-23  Thomas Schwinge  <thomas@codesourcery.com>
+
+	Backport:
+	2019-04-16  Dominique d'Humieres  <dominiq@gcc.gnu.org>
+
+	* g++.dg/lto/pr89358_0.C: Replace dg-* with dg-lto-*.
+
 2020-01-22  Joseph Myers  <joseph@codesourcery.com>
 
 	Backport from mainline:
diff --git a/gcc/testsuite/g++.dg/lto/pr89358_0.C b/gcc/testsuite/g++.dg/lto/pr89358_0.C
index aebd2127c0cf..328c60c2fb18 100644
--- a/gcc/testsuite/g++.dg/lto/pr89358_0.C
+++ b/gcc/testsuite/g++.dg/lto/pr89358_0.C
@@ -1,5 +1,5 @@
-/* { dg-do link } */
-/* { dg-options "-std=c++17"  } */
+/* { dg-lto-do link } */
+/* { dg-lto-options "-std=c++17"  } */
 #include <map>
 
 extern void test();
-- 
2.17.1


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