| Message ID | 20160104113321.GA30608@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On 01/04/2016 04:33 AM, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: >> On 12/31/2015 04:50 AM, Dominik Vogt wrote: >>> The attached patch fixes C++-11 handling of "alignas(0)" which >>> should be ignored but currently generates an error message. A >>> test case is included; the patch has been tested on S390x. Since >>> it's a language issue it should be independent of the backend >>> used. >> >> The patch doesn't handle value-dependent expressions(*). > >> It >> seems that the problem is in handle_aligned_attribute() calling >> check_user_alignment() with the second argument (ALLOW_ZERO) >> set to false. Calling it with true fixes the problem and handles >> value-dependent expressions (I haven't done any more testing beyond >> that). > > Like the attached patch? (Passes the testsuite on s390x.) Yes, like that (though someone other than me needs to approve your patch). > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? AFAICS, both the C and C++ front ends ignore the attribute when check_user_alignment() returns -1 (either on error or when the requested alignment is zero and ALLOW_ZERO is true). Martin PS I wonder what it is about this thread that makes my email client (Thunderbird) include only gcc-patches and krebbel when I hit Reply All and not you. (I had to manually add your email.) It looks like your reply back to me did the same thing. Martin
Can this be approved? https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69089 On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: > > On 12/31/2015 04:50 AM, Dominik Vogt wrote: > > >The attached patch fixes C++-11 handling of "alignas(0)" which > > >should be ignored but currently generates an error message. A > > >test case is included; the patch has been tested on S390x. Since > > >it's a language issue it should be independent of the backend > > >used. > > > > The patch doesn't handle value-dependent expressions(*). > > > It > > seems that the problem is in handle_aligned_attribute() calling > > check_user_alignment() with the second argument (ALLOW_ZERO) > > set to false. Calling it with true fixes the problem and handles > > value-dependent expressions (I haven't done any more testing beyond > > that). > > Like the attached patch? (Passes the testsuite on s390x.) > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? > gcc/c-family/ChangeLog > > PR/69089 > * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the > "aligned" attribute. > > gcc/testsuite/ChangeLog > > PR/69089 > * g++.dg/cpp0x/alignas5.C: New test. > >From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 > From: Dominik Vogt <vogt@de.ibm.com> > Date: Wed, 30 Dec 2015 15:08:52 +0100 > Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an > error message. > > This is required by the C++-11 standard. > --- > gcc/c-family/c-common.c | 2 +- > gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 653d1dc..9eb25a9 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, > else if (TYPE_P (*node)) > type = node, is_type = 1; > > - if ((i = check_user_alignment (align_expr, false)) == -1 > + if ((i = check_user_alignment (align_expr, true)) == -1 > || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) > *no_add_attrs = true; > else if (is_type) > diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > new file mode 100644 > index 0000000..f3252a9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > @@ -0,0 +1,29 @@ > +// PR c++/69089 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wno-attributes" } > + > +alignas (0) int valid1; > +alignas (1 - 1) int valid2; > +struct Tvalid > +{ > + alignas (0) int i; > + alignas (2 * 0) int j; > +}; > + > +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ > +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ > +struct Tinvalid > +{ > + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ > + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ > +}; > + > +template <int N> struct TNvalid1 { alignas (N) int i; }; > +TNvalid1<0> SNvalid1; > +template <int N> struct TNvalid2 { alignas (N) int i; }; > +TNvalid2<1 - 1> SNvalid2; > + > +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid1<-1> SNinvalid1; > +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid2<1 - 2> SNinvalid2; > -- > 2.3.0 > Ciao Dominik ^_^ ^_^
On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: > > On 12/31/2015 04:50 AM, Dominik Vogt wrote: > > >The attached patch fixes C++-11 handling of "alignas(0)" which > > >should be ignored but currently generates an error message. A > > >test case is included; the patch has been tested on S390x. Since > > >it's a language issue it should be independent of the backend > > >used. > > > > The patch doesn't handle value-dependent expressions(*). > > > It > > seems that the problem is in handle_aligned_attribute() calling > > check_user_alignment() with the second argument (ALLOW_ZERO) > > set to false. Calling it with true fixes the problem and handles > > value-dependent expressions (I haven't done any more testing beyond > > that). > > Like the attached patch? (Passes the testsuite on s390x.) > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? > > > Also, in the test, I noticed the definition of the first struct > > is missing the terminating semicolon. > > Yeah. > gcc/c-family/ChangeLog > > PR/69089 > * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the > "aligned" attribute. > > gcc/testsuite/ChangeLog > > PR/69089 > * g++.dg/cpp0x/alignas5.C: New test. > >From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 > From: Dominik Vogt <vogt@de.ibm.com> > Date: Wed, 30 Dec 2015 15:08:52 +0100 > Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an > error message. > > This is required by the C++-11 standard. > --- > gcc/c-family/c-common.c | 2 +- > gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 653d1dc..9eb25a9 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, > else if (TYPE_P (*node)) > type = node, is_type = 1; > > - if ((i = check_user_alignment (align_expr, false)) == -1 > + if ((i = check_user_alignment (align_expr, true)) == -1 > || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) > *no_add_attrs = true; > else if (is_type) > diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > new file mode 100644 > index 0000000..f3252a9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > @@ -0,0 +1,29 @@ > +// PR c++/69089 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wno-attributes" } > + > +alignas (0) int valid1; > +alignas (1 - 1) int valid2; > +struct Tvalid > +{ > + alignas (0) int i; > + alignas (2 * 0) int j; > +}; > + > +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ > +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ > +struct Tinvalid > +{ > + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ > + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ > +}; > + > +template <int N> struct TNvalid1 { alignas (N) int i; }; > +TNvalid1<0> SNvalid1; > +template <int N> struct TNvalid2 { alignas (N) int i; }; > +TNvalid2<1 - 1> SNvalid2; > + > +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid1<-1> SNinvalid1; > +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid2<1 - 2> SNinvalid2; > -- > 2.3.0 > Ciao Dominik ^_^ ^_^
On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: > > On 12/31/2015 04:50 AM, Dominik Vogt wrote: > > >The attached patch fixes C++-11 handling of "alignas(0)" which > > >should be ignored but currently generates an error message. A > > >test case is included; the patch has been tested on S390x. Since > > >it's a language issue it should be independent of the backend > > >used. > > > > The patch doesn't handle value-dependent expressions(*). > > > It > > seems that the problem is in handle_aligned_attribute() calling > > check_user_alignment() with the second argument (ALLOW_ZERO) > > set to false. Calling it with true fixes the problem and handles > > value-dependent expressions (I haven't done any more testing beyond > > that). > > Like the attached patch? (Passes the testsuite on s390x.) > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? > > > Also, in the test, I noticed the definition of the first struct > > is missing the terminating semicolon. > > Yeah. > gcc/c-family/ChangeLog > > PR/69089 > * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the > "aligned" attribute. > > gcc/testsuite/ChangeLog > > PR/69089 > * g++.dg/cpp0x/alignas5.C: New test. > >From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 > From: Dominik Vogt <vogt@de.ibm.com> > Date: Wed, 30 Dec 2015 15:08:52 +0100 > Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an > error message. > > This is required by the C++-11 standard. > --- > gcc/c-family/c-common.c | 2 +- > gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 653d1dc..9eb25a9 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, > else if (TYPE_P (*node)) > type = node, is_type = 1; > > - if ((i = check_user_alignment (align_expr, false)) == -1 > + if ((i = check_user_alignment (align_expr, true)) == -1 > || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) > *no_add_attrs = true; > else if (is_type) > diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > new file mode 100644 > index 0000000..f3252a9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > @@ -0,0 +1,29 @@ > +// PR c++/69089 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wno-attributes" } > + > +alignas (0) int valid1; > +alignas (1 - 1) int valid2; > +struct Tvalid > +{ > + alignas (0) int i; > + alignas (2 * 0) int j; > +}; > + > +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ > +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ > +struct Tinvalid > +{ > + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ > + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ > +}; > + > +template <int N> struct TNvalid1 { alignas (N) int i; }; > +TNvalid1<0> SNvalid1; > +template <int N> struct TNvalid2 { alignas (N) int i; }; > +TNvalid2<1 - 1> SNvalid2; > + > +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid1<-1> SNinvalid1; > +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid2<1 - 2> SNinvalid2; > -- > 2.3.0 > Ciao Dominik ^_^ ^_^
On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: > > On 12/31/2015 04:50 AM, Dominik Vogt wrote: > > >The attached patch fixes C++-11 handling of "alignas(0)" which > > >should be ignored but currently generates an error message. A > > >test case is included; the patch has been tested on S390x. Since > > >it's a language issue it should be independent of the backend > > >used. > > > > The patch doesn't handle value-dependent expressions(*). > > > It > > seems that the problem is in handle_aligned_attribute() calling > > check_user_alignment() with the second argument (ALLOW_ZERO) > > set to false. Calling it with true fixes the problem and handles > > value-dependent expressions (I haven't done any more testing beyond > > that). > > Like the attached patch? (Passes the testsuite on s390x.) > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? > > > Also, in the test, I noticed the definition of the first struct > > is missing the terminating semicolon. > > Yeah. > gcc/c-family/ChangeLog > > PR/69089 > * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the > "aligned" attribute. > > gcc/testsuite/ChangeLog > > PR/69089 > * g++.dg/cpp0x/alignas5.C: New test. > >From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 > From: Dominik Vogt <vogt@de.ibm.com> > Date: Wed, 30 Dec 2015 15:08:52 +0100 > Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an > error message. > > This is required by the C++-11 standard. > --- > gcc/c-family/c-common.c | 2 +- > gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 653d1dc..9eb25a9 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, > else if (TYPE_P (*node)) > type = node, is_type = 1; > > - if ((i = check_user_alignment (align_expr, false)) == -1 > + if ((i = check_user_alignment (align_expr, true)) == -1 > || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) > *no_add_attrs = true; > else if (is_type) > diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > new file mode 100644 > index 0000000..f3252a9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > @@ -0,0 +1,29 @@ > +// PR c++/69089 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wno-attributes" } > + > +alignas (0) int valid1; > +alignas (1 - 1) int valid2; > +struct Tvalid > +{ > + alignas (0) int i; > + alignas (2 * 0) int j; > +}; > + > +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ > +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ > +struct Tinvalid > +{ > + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ > + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ > +}; > + > +template <int N> struct TNvalid1 { alignas (N) int i; }; > +TNvalid1<0> SNvalid1; > +template <int N> struct TNvalid2 { alignas (N) int i; }; > +TNvalid2<1 - 1> SNvalid2; > + > +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid1<-1> SNinvalid1; > +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid2<1 - 2> SNinvalid2; > -- > 2.3.0 > Ciao Dominik ^_^ ^_^
On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: > > On 12/31/2015 04:50 AM, Dominik Vogt wrote: > > >The attached patch fixes C++-11 handling of "alignas(0)" which > > >should be ignored but currently generates an error message. A > > >test case is included; the patch has been tested on S390x. Since > > >it's a language issue it should be independent of the backend > > >used. > > > > The patch doesn't handle value-dependent expressions(*). > > > It > > seems that the problem is in handle_aligned_attribute() calling > > check_user_alignment() with the second argument (ALLOW_ZERO) > > set to false. Calling it with true fixes the problem and handles > > value-dependent expressions (I haven't done any more testing beyond > > that). > > Like the attached patch? (Passes the testsuite on s390x.) > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? > > > Also, in the test, I noticed the definition of the first struct > > is missing the terminating semicolon. > > Yeah. > gcc/c-family/ChangeLog > > PR/69089 > * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the > "aligned" attribute. > > gcc/testsuite/ChangeLog > > PR/69089 > * g++.dg/cpp0x/alignas5.C: New test. > >From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 > From: Dominik Vogt <vogt@de.ibm.com> > Date: Wed, 30 Dec 2015 15:08:52 +0100 > Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an > error message. > > This is required by the C++-11 standard. > --- > gcc/c-family/c-common.c | 2 +- > gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 653d1dc..9eb25a9 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, > else if (TYPE_P (*node)) > type = node, is_type = 1; > > - if ((i = check_user_alignment (align_expr, false)) == -1 > + if ((i = check_user_alignment (align_expr, true)) == -1 > || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) > *no_add_attrs = true; > else if (is_type) > diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > new file mode 100644 > index 0000000..f3252a9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > @@ -0,0 +1,29 @@ > +// PR c++/69089 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wno-attributes" } > + > +alignas (0) int valid1; > +alignas (1 - 1) int valid2; > +struct Tvalid > +{ > + alignas (0) int i; > + alignas (2 * 0) int j; > +}; > + > +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ > +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ > +struct Tinvalid > +{ > + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ > + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ > +}; > + > +template <int N> struct TNvalid1 { alignas (N) int i; }; > +TNvalid1<0> SNvalid1; > +template <int N> struct TNvalid2 { alignas (N) int i; }; > +TNvalid2<1 - 1> SNvalid2; > + > +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid1<-1> SNinvalid1; > +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid2<1 - 2> SNinvalid2; > -- > 2.3.0 > Ciao Dominik ^_^ ^_^
On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: > > On 12/31/2015 04:50 AM, Dominik Vogt wrote: > > >The attached patch fixes C++-11 handling of "alignas(0)" which > > >should be ignored but currently generates an error message. A > > >test case is included; the patch has been tested on S390x. Since > > >it's a language issue it should be independent of the backend > > >used. > > > > The patch doesn't handle value-dependent expressions(*). > > > It > > seems that the problem is in handle_aligned_attribute() calling > > check_user_alignment() with the second argument (ALLOW_ZERO) > > set to false. Calling it with true fixes the problem and handles > > value-dependent expressions (I haven't done any more testing beyond > > that). > > Like the attached patch? (Passes the testsuite on s390x.) > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? > > > Also, in the test, I noticed the definition of the first struct > > is missing the terminating semicolon. > > Yeah. > gcc/c-family/ChangeLog > > PR/69089 > * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the > "aligned" attribute. > > gcc/testsuite/ChangeLog > > PR/69089 > * g++.dg/cpp0x/alignas5.C: New test. > >From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 > From: Dominik Vogt <vogt@de.ibm.com> > Date: Wed, 30 Dec 2015 15:08:52 +0100 > Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an > error message. > > This is required by the C++-11 standard. > --- > gcc/c-family/c-common.c | 2 +- > gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 653d1dc..9eb25a9 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, > else if (TYPE_P (*node)) > type = node, is_type = 1; > > - if ((i = check_user_alignment (align_expr, false)) == -1 > + if ((i = check_user_alignment (align_expr, true)) == -1 > || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) > *no_add_attrs = true; > else if (is_type) > diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > new file mode 100644 > index 0000000..f3252a9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > @@ -0,0 +1,29 @@ > +// PR c++/69089 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wno-attributes" } > + > +alignas (0) int valid1; > +alignas (1 - 1) int valid2; > +struct Tvalid > +{ > + alignas (0) int i; > + alignas (2 * 0) int j; > +}; > + > +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ > +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ > +struct Tinvalid > +{ > + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ > + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ > +}; > + > +template <int N> struct TNvalid1 { alignas (N) int i; }; > +TNvalid1<0> SNvalid1; > +template <int N> struct TNvalid2 { alignas (N) int i; }; > +TNvalid2<1 - 1> SNvalid2; > + > +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid1<-1> SNinvalid1; > +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid2<1 - 2> SNinvalid2; > -- > 2.3.0 > Ciao Dominik ^_^ ^_^
On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: > On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: > > On 12/31/2015 04:50 AM, Dominik Vogt wrote: > > >The attached patch fixes C++-11 handling of "alignas(0)" which > > >should be ignored but currently generates an error message. A > > >test case is included; the patch has been tested on S390x. Since > > >it's a language issue it should be independent of the backend > > >used. > > > > The patch doesn't handle value-dependent expressions(*). > > > It > > seems that the problem is in handle_aligned_attribute() calling > > check_user_alignment() with the second argument (ALLOW_ZERO) > > set to false. Calling it with true fixes the problem and handles > > value-dependent expressions (I haven't done any more testing beyond > > that). > > Like the attached patch? (Passes the testsuite on s390x.) > > But wouldn't an "aligned" attribute be added, allowing the backend > to possibly generate an error or a warning? > > > Also, in the test, I noticed the definition of the first struct > > is missing the terminating semicolon. > > Yeah. > gcc/c-family/ChangeLog > > PR/69089 > * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the > "aligned" attribute. > > gcc/testsuite/ChangeLog > > PR/69089 > * g++.dg/cpp0x/alignas5.C: New test. > >From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 > From: Dominik Vogt <vogt@de.ibm.com> > Date: Wed, 30 Dec 2015 15:08:52 +0100 > Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an > error message. > > This is required by the C++-11 standard. > --- > gcc/c-family/c-common.c | 2 +- > gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 653d1dc..9eb25a9 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, > else if (TYPE_P (*node)) > type = node, is_type = 1; > > - if ((i = check_user_alignment (align_expr, false)) == -1 > + if ((i = check_user_alignment (align_expr, true)) == -1 > || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) > *no_add_attrs = true; > else if (is_type) > diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > new file mode 100644 > index 0000000..f3252a9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C > @@ -0,0 +1,29 @@ > +// PR c++/69089 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wno-attributes" } > + > +alignas (0) int valid1; > +alignas (1 - 1) int valid2; > +struct Tvalid > +{ > + alignas (0) int i; > + alignas (2 * 0) int j; > +}; > + > +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ > +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ > +struct Tinvalid > +{ > + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ > + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ > +}; > + > +template <int N> struct TNvalid1 { alignas (N) int i; }; > +TNvalid1<0> SNvalid1; > +template <int N> struct TNvalid2 { alignas (N) int i; }; > +TNvalid2<1 - 1> SNvalid2; > + > +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid1<-1> SNinvalid1; > +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ > +TNinvalid2<1 - 2> SNinvalid2; > -- > 2.3.0 > Ciao Dominik ^_^ ^_^
On 04/05/2016 03:43 AM, Dominik Vogt wrote: > On Mon, Jan 04, 2016 at 12:33:21PM +0100, Dominik Vogt wrote: >> On Fri, Jan 01, 2016 at 05:53:08PM -0700, Martin Sebor wrote: >>> On 12/31/2015 04:50 AM, Dominik Vogt wrote: >>>> The attached patch fixes C++-11 handling of "alignas(0)" which >>>> should be ignored but currently generates an error message. A >>>> test case is included; the patch has been tested on S390x. Since >>>> it's a language issue it should be independent of the backend >>>> used. >>> >>> The patch doesn't handle value-dependent expressions(*). >> >>> It >>> seems that the problem is in handle_aligned_attribute() calling >>> check_user_alignment() with the second argument (ALLOW_ZERO) >>> set to false. Calling it with true fixes the problem and handles >>> value-dependent expressions (I haven't done any more testing beyond >>> that). >> >> Like the attached patch? (Passes the testsuite on s390x.) >> >> But wouldn't an "aligned" attribute be added, allowing the backend >> to possibly generate an error or a warning? >> >>> Also, in the test, I noticed the definition of the first struct >>> is missing the terminating semicolon. >> >> Yeah. > >> gcc/c-family/ChangeLog >> >> PR/69089 >> * c-common.c (handle_aligned_attribute): Allow 0 as an argument to the >> "aligned" attribute. >> >> gcc/testsuite/ChangeLog >> >> PR/69089 >> * g++.dg/cpp0x/alignas5.C: New test. OK for the trunk. jeff
From 2461293b9070da74950fd0ae055d1239cc69ce67 Mon Sep 17 00:00:00 2001 From: Dominik Vogt <vogt@de.ibm.com> Date: Wed, 30 Dec 2015 15:08:52 +0100 Subject: [PATCH] C++-11: Ingore "alignas(0)" instead of generating an error message. This is required by the C++-11 standard. --- gcc/c-family/c-common.c | 2 +- gcc/testsuite/g++.dg/cpp0x/alignas5.C | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas5.C diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 653d1dc..9eb25a9 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -7804,7 +7804,7 @@ handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, else if (TYPE_P (*node)) type = node, is_type = 1; - if ((i = check_user_alignment (align_expr, false)) == -1 + if ((i = check_user_alignment (align_expr, true)) == -1 || !check_cxx_fundamental_alignment_constraints (*node, i, flags)) *no_add_attrs = true; else if (is_type) diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas5.C b/gcc/testsuite/g++.dg/cpp0x/alignas5.C new file mode 100644 index 0000000..f3252a9 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/alignas5.C @@ -0,0 +1,29 @@ +// PR c++/69089 +// { dg-do compile { target c++11 } } +// { dg-options "-Wno-attributes" } + +alignas (0) int valid1; +alignas (1 - 1) int valid2; +struct Tvalid +{ + alignas (0) int i; + alignas (2 * 0) int j; +}; + +alignas (-1) int invalid1; /* { dg-error "not a positive power of 2" } */ +alignas (1 - 2) int invalid2; /* { dg-error "not a positive power of 2" } */ +struct Tinvalid +{ + alignas (-1) int i; /* { dg-error "not a positive power of 2" } */ + alignas (2 * 0 - 1) int j; /* { dg-error "not a positive power of 2" } */ +}; + +template <int N> struct TNvalid1 { alignas (N) int i; }; +TNvalid1<0> SNvalid1; +template <int N> struct TNvalid2 { alignas (N) int i; }; +TNvalid2<1 - 1> SNvalid2; + +template <int N> struct TNinvalid1 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ +TNinvalid1<-1> SNinvalid1; +template <int N> struct TNinvalid2 { alignas (N) int i; }; /* { dg-error "not a positive power of 2" } */ +TNinvalid2<1 - 2> SNinvalid2; -- 2.3.0