[gcc r17-2414] OpenMP: libgomp.texi + allocate/uses_allocators janitorial updates [PR122748]

Tobias Burnus via Gcc-cvs <[email protected]>
Newsgroups gmane.comp.gcc.cvs
Message-ID <[email protected]> 
https://gcc.gnu.org/g:9e9e22587f7954e079ac68e0e878f1feec7977f8

commit r17-2414-g9e9e22587f7954e079ac68e0e878f1feec7977f8
Author: Tobias Burnus <[email protected]>
Date:   Wed Jul 15 13:45:49 2026 +0200

    OpenMP: libgomp.texi + allocate/uses_allocators janitorial updates [PR122748]
    
    * C only: Fix an ICE on invalid for the allocator clause (undeclared
      identifier); this is PR122748.
    
    * C/C++: Mark trait variables read to avoid bogus 'unused but set'
      warning with uses_allocators.
    
    * libgomp.texi:
      - Update implementation status for uses_allocators,
         claim that C23 is supported (minus bugs), and remove comment
         regarding a not-printed deprecation warning given that there
         is now one.
      - Memory Management Routines: Move 'omp_free' after the allocation
        routines for internal consistency and in line with the spec.
        Add '@c * omp_get_dyn_gprivate_...:: <fixme>/TR15' items to
        '@menu' for the new TR15 routines (actually TR14 but renamed).
        Hence, "grep '@c \*'" should yield all unimplemented or
        undocumented 'omp_' functions as of TR15.
      - nvptx: Fix an URL that was broken by Nvidia but the new one of
        commit r17-1942-g0e2c5d4b2c16c4 wasn't helpful.
    
            PR c/122748
    
    gcc/c/ChangeLog:
    
            * c-parser.cc (c_parser_omp_clause_allocate): Avoid ICE
            when allocator is an error_mark_node.
            (c_parser_omp_clause_uses_allocators): Mark trait var
            as read to avoid 'unused but set' warning.
    
    gcc/cp/ChangeLog:
    
            * parser.cc (cp_parser_omp_clause_uses_allocators): Mark
            trait var as read to avoid 'unused but set' warning.
    
    libgomp/ChangeLog:
    
            * libgomp.texi (Implementation status): Mark two
            uses_allocators items and C23 support as 'Y';
            remove outdated remark regarding a deprecation warning.
            (Memory Management Routines): Move omp_free after
            omp_realloc; add commented @menu entries for new
            TR15 routines.
            (nvptx): Update @uref to point to a better webpage.
    
    gcc/testsuite/ChangeLog:
    
            * c-c++-common/gomp/uses_allocators-1.c: New test.
            * c-c++-common/gomp/uses_allocators-2.c: New test.

Diff:
---
 gcc/c/c-parser.cc                                  |  16 ++-
 gcc/cp/parser.cc                                   |   6 +-
 .../c-c++-common/gomp/uses_allocators-1.c          |  74 ++++++++++++++
 .../c-c++-common/gomp/uses_allocators-2.c          |  23 +++++
 libgomp/libgomp.texi                               | 108 +++++++++++----------
 5 files changed, 169 insertions(+), 58 deletions(-)

diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 4eba29997273..9dc5ba1e3a13 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -19640,11 +19640,14 @@ c_parser_omp_clause_allocate (c_parser *parser, tree list)
 	  location_t expr_loc = c_parser_peek_token (parser)->location;
 	  c_expr expr = c_parser_expr_no_commas (parser, NULL);
 	  expr = convert_lvalue_to_rvalue (expr_loc, expr, false, true);
-	  allocator = expr.value;
-	  allocator = c_fully_fold (allocator, false, NULL);
-	  orig_type = expr.original_type
-		      ? expr.original_type : TREE_TYPE (allocator);
-	  orig_type = TYPE_MAIN_VARIANT (orig_type);
+	  if (expr.value != error_mark_node)
+	    {
+	      allocator = expr.value;
+	      allocator = c_fully_fold (allocator, false, NULL);
+	      orig_type = expr.original_type
+			  ? expr.original_type : TREE_TYPE (allocator);
+	      orig_type = TYPE_MAIN_VARIANT (orig_type);
+	    }
 	}
       if (allocator
 	  && (!INTEGRAL_TYPE_P (TREE_TYPE (allocator))
@@ -19790,6 +19793,7 @@ parse_next:
 	    {
 	      traits_var = expr.value;
 	      traits_var = c_fully_fold (traits_var, false, NULL);
+	      mark_exp_read (traits_var);
 	    }
 	  else
 	    {
@@ -19828,6 +19832,7 @@ parse_next:
 		{
 		  traits_var = expr.value;
 		  traits_var = c_fully_fold (traits_var, false, NULL);
+		  mark_exp_read (traits_var);
 		}
 	      else
 		{
@@ -19879,6 +19884,7 @@ parse_next:
 	  legacy_traits = c_fully_fold (expr.value, false, NULL);
 	  if (legacy_traits == error_mark_node)
 	    goto end;
+	  mark_exp_read (legacy_traits);
 
 	  gcc_rich_location richloc (make_location (alloc_loc, alloc_loc, close_loc));
 	  if (nl == list)
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 95e7544fff30..f455092b989e 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -44183,7 +44183,10 @@ parse_next:
 	    if (traits_var != NULL_TREE)
 	      dup_mod_tok = mod_tok;
 	    else
-	      traits_var = t;
+	      {
+		traits_var = t;
+		mark_exp_read (traits_var);
+	      }
 	  }
 	else
 	  {
@@ -44268,6 +44271,7 @@ parse_next:
 	  legacy_traits = arg;
 	  if (legacy_traits == error_mark_node)
 	    goto end;
+	  mark_exp_read (legacy_traits);
 	  gcc_rich_location richloc (make_location (tok->location,
 						    tok->location, close_loc));
 	  if (nl == list)
diff --git a/gcc/testsuite/c-c++-common/gomp/uses_allocators-1.c b/gcc/testsuite/c-c++-common/gomp/uses_allocators-1.c
new file mode 100644
index 000000000000..8e8f2a861321
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/uses_allocators-1.c
@@ -0,0 +1,74 @@
+// { dg-do compile }
+// { dg-additional-options "-Wall -Wno-deprecated-openmp" }
+
+// Check check that there is no 'unsed but set' warning for 'traits'
+
+// #include <omp.h>
+
+typedef __UINTPTR_TYPE__ omp_uintptr_t;
+
+typedef enum omp_alloctrait_key_t
+{
+  omp_atk_alignment = 2,
+} omp_alloctrait_key_t;
+
+typedef enum omp_alloctrait_value_t
+{
+  omp_atv_default = (__UINTPTR_TYPE__) -1,
+} omp_alloctrait_value_t;
+
+typedef struct omp_alloctrait_t
+{
+  omp_alloctrait_key_t key;
+  omp_uintptr_t value;
+} omp_alloctrait_t;
+
+typedef enum omp_allocator_handle_t
+{
+  omp_null_allocator = 0,
+  __omp_allocator_handle_t_max__ = __UINTPTR_MAX__
+} omp_allocator_handle_t;
+
+typedef enum omp_memspace_handle_t
+{
+  omp_default_mem_space = 0,
+  omp_low_lat_mem_space = 4,
+  __omp_memspace_handle_t_max__ = __UINTPTR_MAX__
+} omp_memspace_handle_t;
+
+
+extern void *omp_alloc (__SIZE_TYPE__, omp_allocator_handle_t);
+extern void omp_free (void *, omp_allocator_handle_t);
+
+// ------------------------
+
+int main() {
+  double x;  // { dg-warning "variable 'x' set but not used" }
+
+  const omp_alloctrait_t traits1[] = {{omp_atk_alignment, 1024}};  // { dg-bogus "variable 'traits1' set but not used" }
+  const omp_alloctrait_t traits2[] = {{omp_atk_alignment, 1024}};  // { dg-bogus "variable 'traits2' set but not used" }
+  const omp_alloctrait_t traits3[] = {{omp_atk_alignment, 1024}};  // { dg-bogus "variable 'traits3' set but not used" }
+  omp_allocator_handle_t alloc1 = omp_null_allocator;
+  omp_allocator_handle_t alloc2 = omp_null_allocator;
+  omp_allocator_handle_t alloc3 = omp_null_allocator;
+
+  #pragma omp target \
+     uses_allocators(traits(traits1), memspace(omp_low_lat_mem_space) : alloc1) \
+     uses_allocators(memspace(omp_default_mem_space), traits(traits2) : alloc2) \
+     uses_allocators(alloc3(traits3))
+    {
+      __builtin_printf ("%p\n", (void*) alloc1);
+      __builtin_printf ("%p\n", (void*) alloc2);
+      __builtin_printf ("%p\n", (void*) alloc3);
+      int *ptr1 = (int*) omp_alloc(sizeof(int), alloc1);
+      int *ptr2 = (int*) omp_alloc(sizeof(int), alloc2);
+      int *ptr3 = (int*) omp_alloc(sizeof(int), alloc3);
+      x = 5;
+      *ptr1 = 5;
+      *ptr2 = 6;
+      *ptr3 = 7;
+      omp_free (ptr1, omp_null_allocator);
+      omp_free (ptr2, omp_null_allocator);
+      omp_free (ptr3, omp_null_allocator);
+    }
+}
diff --git a/gcc/testsuite/c-c++-common/gomp/uses_allocators-2.c b/gcc/testsuite/c-c++-common/gomp/uses_allocators-2.c
new file mode 100644
index 000000000000..25added7fa2d
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/uses_allocators-2.c
@@ -0,0 +1,23 @@
+// { dg-do compile }
+
+// PR c/122748
+// Was previously ICEing
+
+void f()
+{
+  int x;
+#pragma omp target parallel \
+    uses_allocators(omp_thread_mem_alloc) \
+    allocate(omp_thread_mem_alloc: x) private(x)
+  { }
+}
+
+// C
+// { dg-error "'omp_thread_mem_alloc' undeclared \\(first use in this function\\)" "" { target c } 10 }
+// { dg-note  "each undeclared identifier is reported only once for each function it appears in" "" { target c } 10 }
+// { dg-error "allocate' clause must specify an allocator here" "" { target c } 11 }
+
+// C++
+// { dg-error "'omp_thread_mem_alloc' has not been declared" "" { target c++ } 10 }
+// { dg-error "'omp_thread_mem_alloc' was not declared in this scope" "" { target c++ } 11 }
+// { dg-error "'allocate' clause must specify an allocator here" "" { target c++ } 11 }
diff --git a/libgomp/libgomp.texi b/libgomp/libgomp.texi
index d090e2e86d63..687ae1a7cbca 100644
--- a/libgomp/libgomp.texi
+++ b/libgomp/libgomp.texi
@@ -416,14 +416,13 @@ to address of matching mapped list item per 5.1, Sect. 2.21.7.2 @tab N @tab
       allocatables/pointers @tab Y @tab
 @item Optional paired @code{end} directive with @code{dispatch} @tab Y @tab
 @item New @code{memspace} and @code{traits} modifiers for @code{uses_allocators}
-      @tab P @tab Only predefined allocators
+      @tab Y @tab
 @item Deprecation of traits array following the allocator_handle expression in
       @code{uses_allocators} @tab Y @tab
 @item New @code{otherwise} clause as alias for @code{default} on metadirectives
       @tab Y @tab
 @item Deprecation of @code{default} clause on metadirectives @tab Y
-      @tab Both @code{otherwise} and @code{default} are accepted
-      without diagnostics.
+      @tab
 @item Deprecation of delimited form of @code{declare target} @tab Y @tab
 @item Reproducible semantics changed for @code{order(concurrent)} @tab N @tab
 @item @code{allocate} and @code{firstprivate} clauses on @code{scope}
@@ -463,7 +462,7 @@ to address of matching mapped list item per 5.1, Sect. 2.21.7.2 @tab N @tab
 @multitable @columnfractions .60 .10 .25
 @item Features deprecated in versions 5.0, 5.1 and 5.2 were removed
       @tab N/A @tab Backward compatibility
-@item Full support for C23 was added @tab P @tab
+@item Full support for C23 was added @tab Y @tab
 @item Full support for C++23 was added @tab P @tab
 @item Full support for Fortran 2023 was added @tab P @tab
 @item @code{_ALL} suffix to the device-scope environment variables
@@ -543,7 +542,7 @@ to address of matching mapped list item per 5.1, Sect. 2.21.7.2 @tab N @tab
 @item @code{access} allocator trait changes @tab N @tab
 @item New @code{partitioner} value to @code{partition} allocator trait
       @tab N @tab
-@item Semicolon-separated list to @code{uses_allocators} @tab N @tab
+@item Semicolon-separated list to @code{uses_allocators} @tab Y @tab
 @item New @code{need_device_addr} modifier to @code{adjust_args} clause @tab N @tab
 @item @code{interop} clause to @code{dispatch} @tab Y @tab
 @item Scope requirement changes for @code{declare_target} @tab N @tab
@@ -3943,10 +3942,15 @@ They have C linkage and do not throw exceptions.
 * omp_get_default_allocator:: Get the default allocator
 * omp_alloc:: Memory allocation with an allocator
 * omp_aligned_alloc:: Memory allocation with an allocator and alignment
-* omp_free:: Freeing memory allocated with OpenMP routines
 * omp_calloc:: Allocate nullified memory with an allocator
 * omp_aligned_calloc:: Allocate nullified aligned memory with an allocator
 * omp_realloc:: Reallocate memory allocated with OpenMP routines
+* omp_free:: Freeing memory allocated with OpenMP routines
+@c * omp_get_dyn_gprivate_ptr:: <fixme>/TR15
+@c * omp_get_dyn_gprivate_nofb_ptr:: <fixme>/TR15
+@c * omp_get_dyn_gprivate_size:: <fixme>/TR15
+@c * omp_get_dyn_gprivate_memspace:: <fixme>/TR15
+@c * omp_get_gprivate_limit:: <fixme>/TR15
 @end menu
 
 
@@ -4186,51 +4190,6 @@ Memory allocated by @code{omp_aligned_alloc} must be freed using
 
 
 
-@node omp_free
-@subsection @code{omp_free} -- Freeing memory allocated with OpenMP routines
-@table @asis
-@item @emph{Description}:
-The @code{omp_free} routine deallocates memory previously allocated by an
-OpenMP memory-management routine. The @var{ptr} argument must point to such
-memory or be a null pointer; if it is a null pointer, no operation is
-performed.  If specified, the @var{allocator} argument must be either the
-memory allocator that was used for the allocation or @code{omp_null_allocator};
-if it is @code{omp_null_allocator}, the implementation will determine the value
-automatically.
-
-Calling @code{omp_free} invokes undefined behavior if the memory
-was already deallocated or when the used allocator has already been destroyed.
-
-@item @emph{C}:
-@multitable @columnfractions .20 .80
-@item @emph{Prototype}: @tab @code{void omp_free(void *ptr,}
-@item                   @tab @code{  omp_allocator_handle_t allocator)}
-@end multitable
-
-@item @emph{C++}:
-@multitable @columnfractions .20 .80
-@item @emph{Prototype}: @tab @code{void omp_free(void *ptr,}
-@item                   @tab @code{  omp_allocator_handle_t allocator=omp_null_allocator)}
-@end multitable
-
-@item @emph{Fortran}:
-@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_free(ptr, allocator) bind(C)}
-@item                   @tab @code{use, intrinsic :: iso_c_binding, only : c_ptr}
-@item                   @tab @code{type (c_ptr), value :: ptr}
-@item                   @tab @code{integer (omp_allocator_handle_kind), value :: allocator}
-@end multitable
-
-@item @emph{See also}:
-@ref{omp_alloc}, @ref{omp_aligned_alloc}, @ref{omp_calloc},
-@ref{omp_aligned_calloc}, @ref{omp_realloc}
-
-@item @emph{Reference}:
-@uref{https://www.openmp.org, OpenMP specification v5.0}, Section 3.7.7
-@end table
-
-
-
 @node omp_calloc
 @subsection @code{omp_calloc} -- Allocate nullified memory with an allocator
 @table @asis
@@ -4409,6 +4368,51 @@ was already deallocated or when the used allocator has already been destroyed.
 
 
 
+@node omp_free
+@subsection @code{omp_free} -- Freeing memory allocated with OpenMP routines
+@table @asis
+@item @emph{Description}:
+The @code{omp_free} routine deallocates memory previously allocated by an
+OpenMP memory-management routine. The @var{ptr} argument must point to such
+memory or be a null pointer; if it is a null pointer, no operation is
+performed.  If specified, the @var{allocator} argument must be either the
+memory allocator that was used for the allocation or @code{omp_null_allocator};
+if it is @code{omp_null_allocator}, the implementation will determine the value
+automatically.
+
+Calling @code{omp_free} invokes undefined behavior if the memory
+was already deallocated or when the used allocator has already been destroyed.
+
+@item @emph{C}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void omp_free(void *ptr,}
+@item                   @tab @code{  omp_allocator_handle_t allocator)}
+@end multitable
+
+@item @emph{C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void omp_free(void *ptr,}
+@item                   @tab @code{  omp_allocator_handle_t allocator=omp_null_allocator)}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine omp_free(ptr, allocator) bind(C)}
+@item                   @tab @code{use, intrinsic :: iso_c_binding, only : c_ptr}
+@item                   @tab @code{type (c_ptr), value :: ptr}
+@item                   @tab @code{integer (omp_allocator_handle_kind), value :: allocator}
+@end multitable
+
+@item @emph{See also}:
+@ref{omp_alloc}, @ref{omp_aligned_alloc}, @ref{omp_calloc},
+@ref{omp_aligned_calloc}, @ref{omp_realloc}
+
+@item @emph{Reference}:
+@uref{https://www.openmp.org, OpenMP specification v5.0}, Section 3.7.7
+@end table
+
+
+
 @node Tool Control Routine
 @section Tool Control Routine
 
@@ -7888,7 +7892,7 @@ The implementation remark:
 @item OpenMP code that has a @code{requires} directive with @code{self_maps} or
       @code{unified_shared_memory} runs on nvptx devices if and only if
       all of those support the @code{pageableMemoryAccess} property;@footnote{
-      @uref{https://docs.nvidia.com/cuda/cuda-programming-guide/}}
+      @uref{https://docs.nvidia.com/cuda/cuda-programming-guide/04-special-topics/unified-memory.html}}
       otherwise, all nvptx device are removed from the list of available
       devices (``host fallback'').
 @item The default per-warp stack size is 128 kiB; see also @code{-msoft-stack}
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