https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113904
Bug ID: 113904
Summary: [OpenMP][5.0][5.1] Dynamic context selector
'user={condition(expr)}' not handled
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: accepts-invalid, openmp, rejects-valid, wrong-code
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: burnus at gcc dot gnu.org
CC: parras at gcc dot gnu.org, sandra at gcc dot gnu.org
Target Milestone: ---
There are two related problems, leading currently to either
wrong-code (Fortran - alias accepts-invalid OpenMP 5.0)
or rejects-valid OpenMP 5.1 (C/C++).
* Fortran accepts non constant values - but the ME does not handle them.
→ OpenMP 5.1 feature supported for parsing but not in the ME
→ wrong-code
* C/C++ rejects non-const values
→ Rejecting valid 5.1 code
gfortran happily accepts non constant values - while gcc/g++ reject them
test.c:22:58: error: the value of 'foo_use_var2' is not usable in a constant
expression
22 | #pragma omp declare variant (var2)
match(user={condition(foo_use_var2)})
While OpenMP 5.0 only permits
The user selector set defines the condition selector that provides
additional user-defined conditions.
C: The condition(boolean-expr) selector defines a constant expression
that must evaluate to true for the selector to be true.
C++: The condition(boolean-expr) selector defines a constexpr
expression that must evaluate to true for the selector to be true.
Fortran: The condition(logical-expr) selector defines a constant
expression that must evaluate to true for the selector to be true.
Since OpenMP 5.1:
The condition selector contains a single trait-property-expression
that must evaluate to true for the selector to be true.
Any non-constant expression that is evaluated to determine the
suitability of a variant is evaluated according to the data state
trait in the dynamic trait set of the OpenMP context.
The user selector set is dynamic if the condition selector is present
and the expression in the condition selector is not a constant
expression; otherwise, it is static.
