[Flang][OpenMP] Deprecate Allocate Directive (#142378)

As part of OpenMP 5.2, the allocate directive has been deprecated in
favour of the allocators construct for Fortran when an ALLOCATE
statement follows the OpenMP allocate directive.

To enable this in flang, a warning has been added informing the user of
this. Tests to ensure this behaviour is continued are also included.

See also: #110008

Author: Stylie777

flang/lib/Semantics/resolve-directives.cpp

@@ -2073,6 +2073,7 @@ bool OmpAttributeVisitor::Pre(const parser::OpenMPDispatchConstruct &x) {
 }
 
 bool OmpAttributeVisitor::Pre(const parser::OpenMPExecutableAllocate &x) {
+  IssueNonConformanceWarning(llvm::omp::Directive::OMPD_allocate, x.source);
   PushContext(x.source, llvm::omp::Directive::OMPD_allocate);
   const auto &list{std::get<std::optional<parser::OmpObjectList>>(x.t)};
   if (list) {
@@ -3156,6 +3157,9 @@ void OmpAttributeVisitor::IssueNonConformanceWarning(
   case llvm::omp::OMPD_parallel_master_taskloop_simd:
     setAlternativeStr("PARALLEL_MASKED TASKLOOP SIMD");
     break;
+  case llvm::omp::OMPD_allocate:
+    setAlternativeStr("ALLOCATORS");
+    break;
   case llvm::omp::OMPD_target_loop:
   default:;
   }

flang/test/Lower/OpenMP/Todo/omp-declarative-allocate.f90

@@ -1,10 +1,10 @@
 ! This test checks lowering of OpenMP allocate Directive.
 
-// RUN: not flang -fc1 -emit-fir -fopenmp %s 2>&1 | FileCheck %s
+! RUN: not flang -fc1 -emit-fir -fopenmp %s 2>&1 | FileCheck %s
 
 program main
   integer :: x, y
 
-  // CHECK: not yet implemented: OpenMPDeclarativeAllocate
+  ! CHECK: not yet implemented: OpenMPDeclarativeAllocate
   !$omp allocate(x, y)
 end

flang/test/Semantics/OpenMP/allocate-align01.f90

@@ -13,6 +13,7 @@ program allocate_align_tree
     z = 3
     !ERROR: The alignment value should be a constant positive integer
 !$omp allocate(j) align(xx)
+    !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
     !ERROR: The alignment value should be a constant positive integer
 !$omp allocate(xarray) align(-32) allocator(omp_large_cap_mem_alloc)
     allocate(j(z), xarray(t))

flang/test/Semantics/OpenMP/allocate01.f90

@@ -19,6 +19,7 @@ subroutine sema()
     !$omp allocate(y)
         print *, a
 
+    !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
     !ERROR: List items must be declared in the same scoping unit in which the ALLOCATE directive appears
     !$omp allocate(x) allocator(omp_default_mem_alloc)
       allocate ( x(a), darray(a, b) )

flang/test/Semantics/OpenMP/allocate02.f90

@@ -16,9 +16,11 @@ subroutine allocate()
   !ERROR: At most one ALLOCATOR clause can appear on the ALLOCATE directive
   !$omp allocate(x, y) allocator(omp_default_mem_alloc) allocator(omp_default_mem_alloc)
 
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !$omp allocate(darray) allocator(omp_default_mem_alloc)
       allocate ( darray(a, b) )
 
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !ERROR: At most one ALLOCATOR clause can appear on the ALLOCATE directive
   !$omp allocate(darray) allocator(omp_default_mem_alloc) allocator(omp_default_mem_alloc)
       allocate ( darray(a, b) )

flang/test/Semantics/OpenMP/allocate03.f90

@@ -18,6 +18,7 @@ subroutine allocate()
   !ERROR: A variable that is part of another variable (as an array or structure element) cannot appear on the ALLOCATE directive
   !$omp allocate(my_var%array)
 
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !ERROR: A variable that is part of another variable (as an array or structure element) cannot appear on the ALLOCATE directive
   !$omp allocate(darray, my_var%array) allocator(omp_default_mem_alloc)
     allocate ( darray(a, b) )

flang/test/Semantics/OpenMP/allocate05.f90

@@ -13,11 +13,13 @@ subroutine allocate()
   real, dimension (:,:), allocatable :: darray
 
   !$omp target
+      !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
       !$omp allocate allocator(omp_default_mem_alloc)
           allocate ( darray(a, b) )
   !$omp end target
 
   !$omp target
+      !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
       !ERROR: ALLOCATE directives that appear in a TARGET region must specify an allocator clause
       !$omp allocate
           allocate ( darray(a, b) )

flang/test/Semantics/OpenMP/allocate06.f90

@@ -14,6 +14,7 @@ subroutine allocate()
   !ERROR: List items specified in the ALLOCATE directive must not have the ALLOCATABLE attribute unless the directive is associated with an ALLOCATE statement
   !$omp allocate(darray) allocator(omp_default_mem_alloc)
 
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !$omp allocate(darray) allocator(omp_default_mem_alloc)
     allocate(darray(a, b))
 

flang/test/Semantics/OpenMP/allocate09.f90

@@ -12,23 +12,28 @@ subroutine allocate()
   integer, dimension(:), allocatable :: a, b, c, d, e, f, &
                                         g, h, i, j, k, l
 
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !$omp allocate(a) allocator(omp_default_mem_alloc)
     allocate(a(1), b(2))
 
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !$omp allocate(c, d) allocator(omp_default_mem_alloc)
     allocate(c(3), d(4))
 
   !$omp allocate(e) allocator(omp_default_mem_alloc)
   !$omp allocate(f, g) allocator(omp_default_mem_alloc)
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !$omp allocate
     allocate(e(5), f(6), g(7))
 
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !ERROR: Object 'i' in ALLOCATE directive not found in corresponding ALLOCATE statement
   !$omp allocate(h, i) allocator(omp_default_mem_alloc)
     allocate(h(8))
 
   !ERROR: Object 'j' in ALLOCATE directive not found in corresponding ALLOCATE statement
   !$omp allocate(j, k) allocator(omp_default_mem_alloc)
+  !WARNING: OpenMP directive ALLOCATE has been deprecated, please use ALLOCATORS instead.
   !$omp allocate(l) allocator(omp_default_mem_alloc)
     allocate(k(9), l(10))