Re: [patch c++]: Fix for PR/65390

2015-03-31 Thread Marek Polacek 
On Tue, Mar 24, 2015 at 01:14:50AM -0400, Jason Merrill wrote:

Here's my shot at this.

 The problem is that the type is considered dependent in a template but is
 not actually dependent, so we can see the exact same type outside a template

Yeah, I think this is true...

 and it's not dependent.  So, this code is creating the difference:
 
   /* We can only call value_dependent_expression_p on integral constant
  expressions; treat non-constant expressions as dependent, too.  */
   if (processing_template_decl
(type_dependent_expression_p (size)
   || !TREE_CONSTANT (size) || value_dependent_expression_p (size)))
 
 Now that we have instantiation_dependent_expression_p, we should be able to
 use that instead of checking type/value dependency separately.

...but I think there's another place where things go wrong.  ISTM that in
build_cplus_array_type we consider all arrays with non-constant index as
dependent (when processing_template_decl) -- but as the testcase shows, this
is not always true.  The fix then could look like the following, though I
wouldn't be surprised if this was a wrong way how to go about this.

Bootstrapped/regtested on x86_64-linux.  Not a regression, so we might want to
defer this patch to the next stage1.

2015-03-31  Marek Polacek  pola...@redhat.com

PR c++/65390
* tree.c (build_cplus_array_type): Use dependent_type_p rather than
checking for constness.

* g++.dg/template/pr65390.C: New test.

diff --git gcc/cp/tree.c gcc/cp/tree.c
index ef53aff..97bccc0 100644
--- gcc/cp/tree.c
+++ gcc/cp/tree.c
@@ -822,10 +822,9 @@ build_cplus_array_type (tree elt_type, tree index_type)
   if (elt_type == error_mark_node || index_type == error_mark_node)
 return error_mark_node;
 
-  bool dependent
-= (processing_template_decl
-(dependent_type_p (elt_type)
-  || (index_type  !TREE_CONSTANT (TYPE_MAX_VALUE (index_type);
+  bool dependent = (processing_template_decl
+(dependent_type_p (elt_type)
+   || (index_type  dependent_type_p (index_type;
 
   if (elt_type != TYPE_MAIN_VARIANT (elt_type))
 /* Start with an array of the TYPE_MAIN_VARIANT.  */
diff --git gcc/testsuite/g++.dg/template/pr65390.C 
gcc/testsuite/g++.dg/template/pr65390.C
index e69de29..299d22a 100644
--- gcc/testsuite/g++.dg/template/pr65390.C
+++ gcc/testsuite/g++.dg/template/pr65390.C
@@ -0,0 +1,12 @@
+// PR c++/65390
+// { dg-do compile }
+// { dg-options  }
+
+templatetypename T struct shared_ptr { };
+
+templatetypename T, typename Arg
+shared_ptrT make_shared(Arg) { return shared_ptrT(); } // { dg-error 
variably modified type|trying to instantiate }
+
+void f(int n){
+  make_sharedint[n](1); // { dg-error no matching function }
+}

Marek

Re: [patch c++]: Fix for PR/65390

2015-03-31 Thread Marek Polacek 
On Tue, Mar 31, 2015 at 02:32:32PM +0200, Marek Polacek wrote:
 On Tue, Mar 31, 2015 at 02:25:14PM +0200, Kai Tietz wrote:
  Hi,
  
  I had tried same approach as Marek.  For me it solved the PR, but
  caused other regressions on boostrap.  So I dropped the way via
  dependent_type_p.
  
  Well, this bootstrap-issue might be caused by some local changes I had
  forgot to remove, but I doubt it.
  Marek, have you tried to do a boostrap with your patch?
 
 Of course, with --enable-languages=all.  I'll re-run the bootstrap with more
 languages enabled, though.

BTW, are you saying that your fix was exactly the same?  Did you as well check
that index_type is non-null?

Marek

Re: [patch c++]: Fix for PR/65390

2015-03-31 Thread Kai Tietz 
2015-03-31 14:34 GMT+02:00 Marek Polacek pola...@redhat.com:
 On Tue, Mar 31, 2015 at 02:32:32PM +0200, Marek Polacek wrote:
 On Tue, Mar 31, 2015 at 02:25:14PM +0200, Kai Tietz wrote:
  Hi,
 
  I had tried same approach as Marek.  For me it solved the PR, but
  caused other regressions on boostrap.  So I dropped the way via
  dependent_type_p.
 
  Well, this bootstrap-issue might be caused by some local changes I had
  forgot to remove, but I doubt it.
  Marek, have you tried to do a boostrap with your patch?

 Of course, with --enable-languages=all.  I'll re-run the bootstrap with more
 languages enabled, though.

 BTW, are you saying that your fix was exactly the same?  Did you as well check
 that index_type is non-null?

Sure, I checked for index_type.  But by looking closer I used
instantiation_dependent_expression_p - as mentioned by Jason - instead
of dependent_type_p, which seems to make here the difference.

 Marek

Kai

Re: [patch c++]: Fix for PR/65390

2015-03-31 Thread Kai Tietz 
Hi,

I had tried same approach as Marek.  For me it solved the PR, but
caused other regressions on boostrap.  So I dropped the way via
dependent_type_p.

Well, this bootstrap-issue might be caused by some local changes I had
forgot to remove, but I doubt it.
Marek, have you tried to do a boostrap with your patch?

Kai

2015-03-31 13:50 GMT+02:00 Marek Polacek pola...@redhat.com:
 On Tue, Mar 24, 2015 at 01:14:50AM -0400, Jason Merrill wrote:

 Here's my shot at this.

 The problem is that the type is considered dependent in a template but is
 not actually dependent, so we can see the exact same type outside a template

 Yeah, I think this is true...

 and it's not dependent.  So, this code is creating the difference:

   /* We can only call value_dependent_expression_p on integral constant
  expressions; treat non-constant expressions as dependent, too.  */
   if (processing_template_decl
(type_dependent_expression_p (size)
   || !TREE_CONSTANT (size) || value_dependent_expression_p (size)))

 Now that we have instantiation_dependent_expression_p, we should be able to
 use that instead of checking type/value dependency separately.

 ...but I think there's another place where things go wrong.  ISTM that in
 build_cplus_array_type we consider all arrays with non-constant index as
 dependent (when processing_template_decl) -- but as the testcase shows, this
 is not always true.  The fix then could look like the following, though I
 wouldn't be surprised if this was a wrong way how to go about this.

 Bootstrapped/regtested on x86_64-linux.  Not a regression, so we might want to
 defer this patch to the next stage1.

 2015-03-31  Marek Polacek  pola...@redhat.com

 PR c++/65390
 * tree.c (build_cplus_array_type): Use dependent_type_p rather than
 checking for constness.

 * g++.dg/template/pr65390.C: New test.

 diff --git gcc/cp/tree.c gcc/cp/tree.c
 index ef53aff..97bccc0 100644
 --- gcc/cp/tree.c
 +++ gcc/cp/tree.c
 @@ -822,10 +822,9 @@ build_cplus_array_type (tree elt_type, tree index_type)
if (elt_type == error_mark_node || index_type == error_mark_node)
  return error_mark_node;

 -  bool dependent
 -= (processing_template_decl
 -(dependent_type_p (elt_type)
 -  || (index_type  !TREE_CONSTANT (TYPE_MAX_VALUE (index_type);
 +  bool dependent = (processing_template_decl
 +(dependent_type_p (elt_type)
 +   || (index_type  dependent_type_p (index_type;

if (elt_type != TYPE_MAIN_VARIANT (elt_type))
  /* Start with an array of the TYPE_MAIN_VARIANT.  */
 diff --git gcc/testsuite/g++.dg/template/pr65390.C 
 gcc/testsuite/g++.dg/template/pr65390.C
 index e69de29..299d22a 100644
 --- gcc/testsuite/g++.dg/template/pr65390.C
 +++ gcc/testsuite/g++.dg/template/pr65390.C
 @@ -0,0 +1,12 @@
 +// PR c++/65390
 +// { dg-do compile }
 +// { dg-options  }
 +
 +templatetypename T struct shared_ptr { };
 +
 +templatetypename T, typename Arg
 +shared_ptrT make_shared(Arg) { return shared_ptrT(); } // { dg-error 
 variably modified type|trying to instantiate }
 +
 +void f(int n){
 +  make_sharedint[n](1); // { dg-error no matching function }
 +}

 Marek

Re: [patch c++]: Fix for PR/65390

2015-03-31 Thread Marek Polacek 
On Tue, Mar 31, 2015 at 02:25:14PM +0200, Kai Tietz wrote:
 Hi,
 
 I had tried same approach as Marek.  For me it solved the PR, but
 caused other regressions on boostrap.  So I dropped the way via
 dependent_type_p.
 
 Well, this bootstrap-issue might be caused by some local changes I had
 forgot to remove, but I doubt it.
 Marek, have you tried to do a boostrap with your patch?

Of course, with --enable-languages=all.  I'll re-run the bootstrap with more
languages enabled, though.

Marek

Re: [patch c++]: Fix for PR/65390

2015-03-31 Thread Jason Merrill 

OK, thanks.

Jason

Re: [patch c++]: Fix for PR/65390

2015-03-31 Thread Marek Polacek 
On Tue, Mar 31, 2015 at 02:32:32PM +0200, Marek Polacek wrote:
 Of course, with --enable-languages=all.  I'll re-run the bootstrap with more
 languages enabled, though.

--enable-languages=all,obj-c++,go bootstrap passed again on x86_64 and ppc64.

Marek

Re: [patch c++]: Fix for PR/65390

2015-03-23 Thread Jason Merrill 

On 03/20/2015 10:53 AM, Kai Tietz wrote:

 * tree.c (strip_typedefs): Ignore alignment
 difference during processing template.

+  || (processing_template_decl
+   TYPE_ALIGN (t) != TYPE_ALIGN (result)))


Your change is actually ignoring alignment differences when *not* 
processing a template, which isn't what we want.


The problem is that the type is considered dependent in a template but 
is not actually dependent, so we can see the exact same type outside a 
template and it's not dependent.  So, this code is creating the difference:



  /* We can only call value_dependent_expression_p on integral constant
 expressions; treat non-constant expressions as dependent, too.  */
  if (processing_template_decl
   (type_dependent_expression_p (size)
  || !TREE_CONSTANT (size) || value_dependent_expression_p (size)))


Now that we have instantiation_dependent_expression_p, we should be able 
to use that instead of checking type/value dependency separately.


Jason

Re: [patch c++]: Fix for PR/65390

2015-03-20 Thread Kai Tietz 
Hello,

the problem here is that for cases of vla-array-types, the types don't
get finally layouted in build_cplus_array_type.  So the type-alignment
isn't set in such cases for the resulting type.

ChangeLog

2015-03-20  Kai Tietz  kti...@redhat.com

PR c++/65390
* tree.c (strip_typedefs): Ignore alignment
difference during processing template.

2015-03-20  Kai Tietz  kti...@redhat.com

PR c++/65390
* g++.dg/template/pr65390.C: New file.

Tested on x86_64-unknown-linux-gnu.  Ok for apply?

Regards,
Kai

Index: gcc/gcc/cp/tree.c
===
--- gcc.orig/gcc/cp/tree.c
+++ gcc/gcc/cp/tree.c
@@ -1356,7 +1356,8 @@ strip_typedefs (tree t)
   if (!result)
   result = TYPE_MAIN_VARIANT (t);
   if (TYPE_USER_ALIGN (t) != TYPE_USER_ALIGN (result)
-  || TYPE_ALIGN (t) != TYPE_ALIGN (result))
+  || (processing_template_decl
+   TYPE_ALIGN (t) != TYPE_ALIGN (result)))
 {
   gcc_assert (TYPE_USER_ALIGN (t));
   if (TYPE_ALIGN (t) == TYPE_ALIGN (result))
Index: gcc/gcc/testsuite/g++.dg/template/pr65390.C
===
--- /dev/null
+++ gcc/gcc/testsuite/g++.dg/template/pr65390.C
@@ -0,0 +1,12 @@
+// { dg-do compile }
+// { dg-options -Wno-vla }
+templatetypename T struct shared_ptr { };
+
+templatetypename T, typename Arg
+shared_ptrT make_shared(Arg) { return shared_ptrT(); } // {
dg-message note }
+// { dg-warning ignoring attributes template { target *-*-* } 6 }
+
+void f(int n){
+  make_sharedint[n](1); // { dg-error no matching }
+}
+// { dg-error variably modified type|trying to instantiate type {
target *-*-* } 10 }

Re: [patch c++]: Fix for PR/65390

2015-03-17 Thread Jason Merrill 

On 03/16/2015 03:22 PM, Kai Tietz wrote:

2015-03-16 19:07 GMT+01:00 Jason Merrill ja...@redhat.com:

If there is an alignment mismatch without user intervention, there is a
problem, we can't just ignore it.

Where we run into trouble is with array types where the version built
earlier has not been laid out yet but the new one has been.  I've been
trying to deal with that by making sure that we lay out the original type as
well, but obviously that isn't working for this case.  Why not?


Well, TYPE_ALIGN (t) is set to 32, and it differs to TYPE_ALIGN
(result) (value 8), and TYPE_USER_ALIGN isn't set.


I suppose we could avoid checking TYPE_ALIGN if neither TYPE_USER_ALIGN nor
TYPE_SIZE are set on 't', but checking TYPE_USER_ALIGN isn't enough.


For t TYPE_SIZE is set, but it isn't a constant (as it is an variably
modified type).


TYPE_ALIGN should still be correct in that case.  So we need to figure 
out why result is getting the wrong alignment.


Jason

Re: [patch c++]: Fix for PR/65390

2015-03-17 Thread Kai Tietz 
2015-03-17 13:36 GMT+01:00 Jason Merrill ja...@redhat.com:
 On 03/16/2015 03:22 PM, Kai Tietz wrote:

 2015-03-16 19:07 GMT+01:00 Jason Merrill ja...@redhat.com:

 If there is an alignment mismatch without user intervention, there is a
 problem, we can't just ignore it.

 Where we run into trouble is with array types where the version built
 earlier has not been laid out yet but the new one has been.  I've been
 trying to deal with that by making sure that we lay out the original type
 as
 well, but obviously that isn't working for this case.  Why not?


 Well, TYPE_ALIGN (t) is set to 32, and it differs to TYPE_ALIGN
 (result) (value 8), and TYPE_USER_ALIGN isn't set.

 I suppose we could avoid checking TYPE_ALIGN if neither TYPE_USER_ALIGN
 nor
 TYPE_SIZE are set on 't', but checking TYPE_USER_ALIGN isn't enough.


 For t TYPE_SIZE is set, but it isn't a constant (as it is an variably
 modified type).


 TYPE_ALIGN should still be correct in that case.  So we need to figure out
 why result is getting the wrong alignment.

 Jason


By debugging in build_cplus_array_type I see that type is marked as
dependent.  This is caused by type-max being an expression
non-constant.  So we later on don't layout this type.
So result isn't a comlete layout type.  by callling layout_type on
result, alignment fits.

Kai

Re: [patch c++]: Fix for PR/65390

2015-03-16 Thread Jason Merrill 
If there is an alignment mismatch without user intervention, there is a 
problem, we can't just ignore it.


Where we run into trouble is with array types where the version built 
earlier has not been laid out yet but the new one has been.  I've been 
trying to deal with that by making sure that we lay out the original 
type as well, but obviously that isn't working for this case.  Why not?


I suppose we could avoid checking TYPE_ALIGN if neither TYPE_USER_ALIGN 
nor TYPE_SIZE are set on 't', but checking TYPE_USER_ALIGN isn't enough.


Jason

Re: [patch c++]: Fix for PR/65390

2015-03-16 Thread Kai Tietz 
2015-03-16 19:07 GMT+01:00 Jason Merrill ja...@redhat.com:
 If there is an alignment mismatch without user intervention, there is a
 problem, we can't just ignore it.

 Where we run into trouble is with array types where the version built
 earlier has not been laid out yet but the new one has been.  I've been
 trying to deal with that by making sure that we lay out the original type as
 well, but obviously that isn't working for this case.  Why not?

Well, TYPE_ALIGN (t) is set to 32, and it differs to TYPE_ALIGN
(result) (value 8), and TYPE_USER_ALIGN isn't set.

 I suppose we could avoid checking TYPE_ALIGN if neither TYPE_USER_ALIGN nor
 TYPE_SIZE are set on 't', but checking TYPE_USER_ALIGN isn't enough.

For t TYPE_SIZE is set, but it isn't a constant (as it is an variably
modified type).  So we could add here additional check if TYPE_SIZE is
a integer-constant?

Something like this condition you mean?

...
if (TYPE_USER_ALIGN (t) != TYPE_USER_ALIGN (result)
|| ((TYPE_USER_ALIGN (t) || TREE_CODE (TYPE_SIZE (t)) == INTEGER_CST)
 TYPE_ALIGN (t) != TYPE_ALIGN (result)))
  {
...
 Jason

Kai