Merge 'c-c++-common/goacc/routine-6.c' into 'c-c++-common/goacc/routine-5.c', and document current C/C++ difference (was: [PATCH] openacc: Fix up C++ #pragma acc routine handling [PR101731])
Commit Message
Hi!
On 2021-11-22T16:02:31+0100, Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> On Mon, Nov 22, 2021 at 03:49:42PM +0100, Thomas Schwinge wrote:
>> Then, regarding the user-visible behavior:
>>
>> > +#pragma acc routine /* { dg-error "not immediately followed by a single function declaration or definition" "" { target c++ } } */
>> > +int foo (int bar ());
>>
>> So in C++ we now refuse, but in C we do accept this. I suppose I shall
>> look into making C behave the same way -- unless there is a reason for
>> the different behavior? And/or, is it actually is useful to allow such
>> nested usage? Per its associated clauses, an OpenACC 'routine' directive
>> really is meant to apply to one function only, in contrast to OpenMP
>> 'target declare'. But the question is whether we should raise an error
>> for the example above, or whether the 'routine' shall just apply to 'foo'
>> but not 'bar', but without an error diagnostic?
>
> All I've verified is that our OpenMP code handles it the same way,
Thanks for the explanation.
Pushed to master branch commit 67fdcc8835665b5bc13652205e815e498d65c5a1
"Merge 'c-c++-common/goacc/routine-6.c' into
'c-c++-common/goacc/routine-5.c', and document current C/C++ difference",
see attached.
Grüße
Thomas
> i.e.
> #pragma omp declare simd
> int foo (int bar ());
> is accepted in C and rejected in C++.
> I guess one question is to check if it is in both languages actually
> the same thing. If we want to accept it in C++ and let the pragma
> apply only to the outer declaration, I guess we'd need to temporarily
> set to NULL parser->omp_declare_simd and parser->oacc_routine while
> parsing the parameters of a function declaration or definition.
> At least OpenMP is fairly fuzzy here, the reason we error on
> #pragma omp declare simd
> int foo (), i;
> has been mainly some discussions in the lang committee and the fact
> that it talks about a single declaration, not all affected declarations.
> Whether int foo (int bar ()); should be in that light treated as two
> function declarations or one with another one nested in it and irrelevant
> for it is unclear.
>
> Jakub
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From 67fdcc8835665b5bc13652205e815e498d65c5a1 Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <thomas@codesourcery.com>
Date: Mon, 22 Nov 2021 16:09:09 +0100
Subject: [PATCH] Merge 'c-c++-common/goacc/routine-6.c' into
'c-c++-common/goacc/routine-5.c', and document current C/C++ difference
gcc/testsuite/
* c-c++-common/goacc/routine-6.c: Merge into...
* c-c++-common/goacc/routine-5.c: ... this, and document current
C/C++ difference.
---
gcc/testsuite/c-c++-common/goacc/routine-5.c | 8 ++++++++
gcc/testsuite/c-c++-common/goacc/routine-6.c | 4 ----
2 files changed, 8 insertions(+), 4 deletions(-)
delete mode 100644 gcc/testsuite/c-c++-common/goacc/routine-6.c
@@ -94,6 +94,14 @@ typedef struct c_2 c_2;
#pragma acc routine /* { dg-error ".#pragma acc routine. not immediately followed by function declaration or definition" } */
struct d_2 {} d_2;
+/* PR c++/101731 */
+/* Regarding the current C/C++ difference, see
+ <http://mid.mail-archive.com/20211122150231.GP2646553@tucnak>. */
+#pragma acc routine /* { dg-error "not immediately followed by a single function declaration or definition" "" { target c++ } } */
+int pr101731_foo (int pr101731_bar ());
+#pragma acc routine (pr101731_foo) vector /* { dg-error "has already been marked with an OpenACC 'routine' directive" "" { target c } } */
+#pragma acc routine (pr101731_bar) vector /* { dg-error "'pr101731_bar' has not been declared" } */
+
#pragma acc routine /* { dg-error ".#pragma acc routine. not immediately followed by function declaration or definition" } */
#pragma acc routine
int fn4 (void);
deleted file mode 100644
@@ -1,4 +0,0 @@
-/* PR c++/101731 */
-
-#pragma acc routine /* { dg-error "not immediately followed by a single function declaration or definition" "" { target c++ } } */
-int foo (int bar ());
--
2.34.1