[OpenMP][Flang] Change the OmpDefaultMapperName suffix #168399

TIFitis · 2025-11-17T16:31:20Z

This PR fixes a Fortran syntax violation in the OpenMP default mapper naming convention. The suffix .omp.default.mapper contains dots which are invalid in Fortran identifiers, causing failures when mappers are written to and read from module files. The fix changes the suffix to _omp_default_mapper which uses underscores instead of dots, complying with Fortran syntax rules.

Key changes:

Changed OmpDefaultMapperName constant from .omp.default.mapper to _omp_default_mapper
Added GetUltimate() calls in mapper symbol resolution to properly handle symbols across module boundaries
Added new test case verifying default mappers work correctly when defined in a module and used in consuming programs

This fixes #168336.

The ".omp.default.mapper" does not follow the Fortran syntax rules. As such when emitted to the module file, it triggered a syntax failure when trying to read from the module file. This patch fixes it by changing the suffix to "_omp_default_mapper". New tests's have been added to check default mappers work correctly across module files. This fixes llvm#168336.

llvmbot · 2025-11-17T16:31:54Z

@llvm/pr-subscribers-flang-fir-hlfir
@llvm/pr-subscribers-flang-openmp

@llvm/pr-subscribers-flang-semantics

Author: Akash Banerjee (TIFitis)

Changes

The ".omp.default.mapper" does not follow the Fortran syntax rules. As such when emitted to the module file, it triggered a syntax failure when trying to read from the module file. This patch fixes it by changing the suffix to "_omp_default_mapper". New tests's have been added to check default mappers work correctly across module files.

This fixes #168336.

Full diff: https://github.com/llvm/llvm-project/pull/168399.diff

10 Files Affected:

(modified) flang/lib/Lower/OpenMP/ClauseProcessor.cpp (+2-1)
(modified) flang/lib/Lower/OpenMP/OpenMP.cpp (+2-2)
(modified) flang/test/Lower/OpenMP/declare-mapper.f90 (+39-4)
(modified) flang/test/Lower/OpenMP/derived-type-map.f90 (+1-1)
(modified) flang/test/Lower/OpenMP/map-mapper.f90 (+2-2)
(modified) flang/test/Lower/OpenMP/target.f90 (+1-1)
(modified) flang/test/Parser/OpenMP/declare-mapper-unparse.f90 (+1-1)
(modified) flang/test/Parser/OpenMP/openmp6-directive-spellings.f90 (+1-1)
(modified) flang/test/Semantics/OpenMP/declare-mapper-symbols.f90 (+1-1)
(modified) llvm/include/llvm/Frontend/OpenMP/OMPConstants.h (+1-1)

diff --git a/flang/lib/Lower/OpenMP/ClauseProcessor.cpp b/flang/lib/Lower/OpenMP/ClauseProcessor.cpp
index e018a2d937435..4a392381287d5 100644
--- a/flang/lib/Lower/OpenMP/ClauseProcessor.cpp
+++ b/flang/lib/Lower/OpenMP/ClauseProcessor.cpp
@@ -1278,7 +1278,8 @@ void ClauseProcessor::processMapObjects(
     std::string mapperIdName =
         typeSpec->name().ToString() + llvm::omp::OmpDefaultMapperName;
     if (auto *sym = converter.getCurrentScope().FindSymbol(mapperIdName)) {
-      mapperIdName = converter.mangleName(mapperIdName, sym->owner());
+      mapperIdName =
+          converter.mangleName(mapperIdName, sym->GetUltimate().owner());
     } else {
       mapperIdName = converter.mangleName(mapperIdName, *typeSpec->GetScope());
     }
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index c3f670c62da06..4ebf2c7764cf3 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -2612,8 +2612,8 @@ genTargetOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
               typeSpec->name().ToString() + llvm::omp::OmpDefaultMapperName;
           if (auto *mapperSym =
                   converter.getCurrentScope().FindSymbol(mapperIdName))
-            mapperIdName =
-                converter.mangleName(mapperIdName, mapperSym->owner());
+            mapperIdName = converter.mangleName(
+                mapperIdName, mapperSym->GetUltimate().owner());
           else
             mapperIdName =
                 converter.mangleName(mapperIdName, *typeSpec->GetScope());
diff --git a/flang/test/Lower/OpenMP/declare-mapper.f90 b/flang/test/Lower/OpenMP/declare-mapper.f90
index 0266365cf03c0..a24d6bd0bf946 100644
--- a/flang/test/Lower/OpenMP/declare-mapper.f90
+++ b/flang/test/Lower/OpenMP/declare-mapper.f90
@@ -9,6 +9,8 @@
 ! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 %t/omp-declare-mapper-6.f90 -o - | FileCheck %t/omp-declare-mapper-6.f90
 ! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -module-dir %t %t/omp-declare-mapper-7.mod.f90 -o - >/dev/null
 ! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -J %t %t/omp-declare-mapper-7.use.f90 -o - | FileCheck %t/omp-declare-mapper-7.use.f90
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -module-dir %t %t/omp-declare-mapper-8.mod.f90 -o - >/dev/null
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -J %t %t/omp-declare-mapper-8.use.f90 -o - | FileCheck %t/omp-declare-mapper-8.use.f90
 
 !--- omp-declare-mapper-1.f90
 subroutine declare_mapper_1
@@ -26,7 +28,7 @@ subroutine declare_mapper_1
    end type
    type(my_type2)        :: t
    real                   :: x, y(nvals)
-   !CHECK:omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_1my_type\.omp\.default\.mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_1Tmy_type\{num_vals:i32,values:!fir\.box<!fir\.heap<!fir\.array<\?xi32>>>\}>]] {
+   !CHECK:omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_1my_type_omp_default_mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_1Tmy_type\{num_vals:i32,values:!fir\.box<!fir\.heap<!fir\.array<\?xi32>>>\}>]] {
    !CHECK:      ^bb0(%[[VAL_0:.*]]: !fir.ref<[[MY_TYPE]]>):
    !CHECK:        %[[VAL_1:.*]]:2 = hlfir.declare %[[VAL_0]] {uniq_name = "_QFdeclare_mapper_1Evar"} : (!fir.ref<[[MY_TYPE]]>) -> (!fir.ref<[[MY_TYPE]]>, !fir.ref<[[MY_TYPE]]>)
    !CHECK:        %[[VAL_2:.*]] = hlfir.designate %[[VAL_1]]#0{"values"}   {fortran_attrs = #fir.var_attrs<allocatable>} : (!fir.ref<[[MY_TYPE]]>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
@@ -153,7 +155,7 @@ subroutine declare_mapper_4
       integer              :: num
    end type
 
-   !CHECK: omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_4my_type.omp.default.mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_4Tmy_type\{num:i32\}>]]
+   !CHECK: omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_4my_type_omp_default_mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_4Tmy_type\{num:i32\}>]]
    !$omp declare mapper (my_type :: var) map (var%num)
 
    type(my_type) :: a
@@ -185,9 +187,9 @@ program declare_mapper_5
    end type
 
    !CHECK: omp.declare_mapper @[[INNER_MAPPER_NAMED:_QQFFuse_innermy_mapper]] : [[MY_TYPE:!fir\.type<_QFTmytype\{x:i32,y:i32\}>]]
-   !CHECK: omp.declare_mapper @[[INNER_MAPPER_DEFAULT:_QQFFuse_innermytype.omp.default.mapper]] : [[MY_TYPE]]
+   !CHECK: omp.declare_mapper @[[INNER_MAPPER_DEFAULT:_QQFFuse_innermytype_omp_default_mapper]] : [[MY_TYPE]]
    !CHECK: omp.declare_mapper @[[OUTER_MAPPER_NAMED:_QQFmy_mapper]] : [[MY_TYPE]]
-   !CHECK: omp.declare_mapper @[[OUTER_MAPPER_DEFAULT:_QQFmytype.omp.default.mapper]] : [[MY_TYPE]]
+   !CHECK: omp.declare_mapper @[[OUTER_MAPPER_DEFAULT:_QQFmytype_omp_default_mapper]] : [[MY_TYPE]]
    !$omp declare mapper(mytype :: var) map(tofrom: var%x)
    !$omp declare mapper(my_mapper : mytype :: var) map(tofrom: var%y)
 
@@ -325,3 +327,36 @@ program use_module_mapper
     a%x = 42
   !$omp end target
 end program use_module_mapper
+
+!--- omp-declare-mapper-8.mod.f90
+! Module with a default DECLARE MAPPER to be compiled separately.
+module default_mapper_mod
+  implicit none
+  type :: dtype
+    integer :: x
+  end type dtype
+  !$omp declare mapper(dtype :: v) map(tofrom: v%x)
+end module default_mapper_mod
+
+!--- omp-declare-mapper-8.use.f90
+! Consumer program that USEs the module and relies on the default mapper.
+! CHECK: omp.declare_mapper @{{.*dtype_omp_default_mapper}} : !fir.type<_QMdefault_mapper_modTdtype{x:i32}>
+! CHECK: %{{.*}} = omp.map.info {{.*}} map_clauses(tofrom) {{.*}} mapper(@{{.*dtype_omp_default_mapper}}) {{.*}} {name = "a"}
+! CHECK: %{{.*}} = omp.map.info {{.*}} map_clauses(tofrom) {{.*}} mapper(@{{.*dtype_omp_default_mapper}}) {{.*}} {name = "a"}
+! CHECK: %{{.*}} = omp.map.info {{.*}} map_clauses(implicit, tofrom) {{.*}} mapper(@{{.*dtype_omp_default_mapper}}) {{.*}} {name = "a"}
+program use_module_default_mapper
+  use default_mapper_mod
+  implicit none
+  type(dtype) :: a
+  !$omp target map(a)
+    a%x = 7
+  !$omp end target
+
+  !$omp target map(mapper(default) : a)
+    a%x = 8
+  !$omp end target
+
+  !$omp target
+    a%x = 8
+  !$omp end target
+end program use_module_default_mapper
diff --git a/flang/test/Lower/OpenMP/derived-type-map.f90 b/flang/test/Lower/OpenMP/derived-type-map.f90
index 228e86d9e4dfd..921dd5663f8c5 100644
--- a/flang/test/Lower/OpenMP/derived-type-map.f90
+++ b/flang/test/Lower/OpenMP/derived-type-map.f90
@@ -1,6 +1,6 @@
 !RUN: %flang_fc1 -emit-hlfir -fopenmp %s -o - | FileCheck %s
 
-!CHECK: omp.declare_mapper @[[MAPPER1:_QQFmaptype_derived_implicit_allocatablescalar_and_array.omp.default.mapper]] : !fir.type<_QFmaptype_derived_implicit_allocatableTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}> {
+!CHECK: omp.declare_mapper @[[MAPPER1:_QQFmaptype_derived_implicit_allocatablescalar_and_array_omp_default_mapper]] : !fir.type<_QFmaptype_derived_implicit_allocatableTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}> {
 
 !CHECK: %[[ALLOCA:.*]] = fir.alloca !fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}> {bindc_name = "scalar_arr", uniq_name = "_QFmaptype_derived_implicitEscalar_arr"}
 !CHECK: %[[DECLARE:.*]]:2 = hlfir.declare %[[ALLOCA]] {uniq_name = "_QFmaptype_derived_implicitEscalar_arr"} : (!fir.ref<!fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}>>) -> (!fir.ref<!fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}>>, !fir.ref<!fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}>>)
diff --git a/flang/test/Lower/OpenMP/map-mapper.f90 b/flang/test/Lower/OpenMP/map-mapper.f90
index 91564bfc7bc46..8934fbb5d6edf 100644
--- a/flang/test/Lower/OpenMP/map-mapper.f90
+++ b/flang/test/Lower/OpenMP/map-mapper.f90
@@ -8,7 +8,7 @@ program p
    !$omp declare mapper(xx : t1 :: nn) map(to: nn, nn%x)
    !$omp declare mapper(t1 :: nn) map(from: nn)
 
-   !CHECK-LABEL: omp.declare_mapper @_QQFt1.omp.default.mapper : !fir.type<_QFTt1{x:!fir.array<256xi32>}>
+   !CHECK-LABEL: omp.declare_mapper @_QQFt1_omp_default_mapper : !fir.type<_QFTt1{x:!fir.array<256xi32>}>
    !CHECK-LABEL: omp.declare_mapper @_QQFxx : !fir.type<_QFTt1{x:!fir.array<256xi32>}>
 
    type(t1) :: a, b
@@ -20,7 +20,7 @@ program p
    end do
    !$omp end target
 
-   !CHECK: %[[MAP_B:.*]] = omp.map.info var_ptr(%{{.*}} : {{.*}}, {{.*}}) map_clauses(tofrom) capture(ByRef) mapper(@_QQFt1.omp.default.mapper) -> {{.*}} {name = "b"}
+   !CHECK: %[[MAP_B:.*]] = omp.map.info var_ptr(%{{.*}} : {{.*}}, {{.*}}) map_clauses(tofrom) capture(ByRef) mapper(@_QQFt1_omp_default_mapper) -> {{.*}} {name = "b"}
    !CHECK: omp.target map_entries(%[[MAP_B]] -> %{{.*}}, %{{.*}} -> %{{.*}} : {{.*}}, {{.*}}) {
    !$omp target map(mapper(default) : b)
    do i = 1, n
diff --git a/flang/test/Lower/OpenMP/target.f90 b/flang/test/Lower/OpenMP/target.f90
index 94907ba3ae74a..7cd642bcf23cf 100644
--- a/flang/test/Lower/OpenMP/target.f90
+++ b/flang/test/Lower/OpenMP/target.f90
@@ -529,7 +529,7 @@ subroutine omp_target_device_ptr
    use iso_c_binding, only : c_ptr, c_loc
    type(c_ptr) :: a
    integer, target :: b
-   !CHECK: %[[MAP:.*]] = omp.map.info var_ptr({{.*}})   map_clauses(tofrom) capture(ByRef) mapper(@[[CPTR_DEFAULT:_QQM__fortran_builtinsc_ptr\.omp\.default\.mapper]]) -> {{.*}} {name = "a"}
+   !CHECK: %[[MAP:.*]] = omp.map.info var_ptr({{.*}})   map_clauses(tofrom) capture(ByRef) mapper(@[[CPTR_DEFAULT:_QQM__fortran_builtinsc_ptr_omp_default_mapper]]) -> {{.*}} {name = "a"}
    !CHECK: omp.target_data map_entries(%[[MAP]]{{.*}}) use_device_ptr({{.*}} -> %[[VAL_1:.*]] : !fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>)
    !$omp target data map(tofrom: a) use_device_ptr(a)
    !CHECK: {{.*}} = fir.coordinate_of %[[VAL_1:.*]], __address : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>) -> !fir.ref<i64>
diff --git a/flang/test/Parser/OpenMP/declare-mapper-unparse.f90 b/flang/test/Parser/OpenMP/declare-mapper-unparse.f90
index b53bf5ce10557..9da6674c3a58d 100644
--- a/flang/test/Parser/OpenMP/declare-mapper-unparse.f90
+++ b/flang/test/Parser/OpenMP/declare-mapper-unparse.f90
@@ -29,7 +29,7 @@ program main
 
 !PARSE-TREE:      OpenMPDeclareMapperConstruct
 !PARSE-TREE:        OmpMapperSpecifier
-!PARSE-TREE:         string = 'ty.omp.default.mapper'
+!PARSE-TREE:         string = 'ty_omp_default_mapper'
 !PARSE-TREE:         TypeSpec -> DerivedTypeSpec
 !PARSE-TREE:           Name = 'ty'
 !PARSE-TREE:         Name = 'mapped'
diff --git a/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90 b/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90
index 50a38c6494aa6..7a627913f9555 100644
--- a/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90
+++ b/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90
@@ -57,7 +57,7 @@ subroutine f01
 !PARSE-TREE: DeclarationConstruct -> SpecificationConstruct -> OpenMPDeclarativeConstruct -> OpenMPDeclareMapperConstruct -> OmpDirectiveSpecification
 !PARSE-TREE: | OmpDirectiveName -> llvm::omp::Directive = declare mapper
 !PARSE-TREE: | OmpArgumentList -> OmpArgument -> OmpMapperSpecifier
-!PARSE-TREE: | | string = 't.omp.default.mapper'
+!PARSE-TREE: | | string = 't_omp_default_mapper'
 !PARSE-TREE: | | TypeSpec -> DerivedTypeSpec
 !PARSE-TREE: | | | Name = 't'
 !PARSE-TREE: | | Name = 'v'
diff --git a/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90 b/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
index 5d77540aa6453..9a1b86758357f 100644
--- a/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
+++ b/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
@@ -13,7 +13,7 @@ program main
 !! Note, symbols come out in their respective scope, but not in declaration order.
 !CHECK: mymapper: MapperDetails
 !CHECK: ty: DerivedType components: x
-!CHECK: ty.omp.default.mapper: MapperDetails
+!CHECK: ty_omp_default_mapper: MapperDetails
 !CHECK: DerivedType scope: ty
 !CHECK: OtherConstruct scope:
 !CHECK: mapped (OmpMapToFrom) {{.*}} ObjectEntity type: TYPE(ty)
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h b/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h
index 1ac9ac040468c..58fd8a490c04a 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h
+++ b/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h
@@ -201,7 +201,7 @@ enum class OMPDynGroupprivateFallbackType : uint64_t {
 };
 
 // Default OpenMP mapper name suffix.
-inline constexpr const char *OmpDefaultMapperName = ".omp.default.mapper";
+inline constexpr const char *OmpDefaultMapperName = "_omp_default_mapper";
 
 /// Values for bit flags used to specify the mapping type for
 /// offloading.

llvmbot · 2025-11-17T16:31:55Z

@llvm/pr-subscribers-flang-parser

Author: Akash Banerjee (TIFitis)

Changes

The ".omp.default.mapper" does not follow the Fortran syntax rules. As such when emitted to the module file, it triggered a syntax failure when trying to read from the module file. This patch fixes it by changing the suffix to "_omp_default_mapper". New tests's have been added to check default mappers work correctly across module files.

This fixes #168336.

Full diff: https://github.com/llvm/llvm-project/pull/168399.diff

10 Files Affected:

(modified) flang/lib/Lower/OpenMP/ClauseProcessor.cpp (+2-1)
(modified) flang/lib/Lower/OpenMP/OpenMP.cpp (+2-2)
(modified) flang/test/Lower/OpenMP/declare-mapper.f90 (+39-4)
(modified) flang/test/Lower/OpenMP/derived-type-map.f90 (+1-1)
(modified) flang/test/Lower/OpenMP/map-mapper.f90 (+2-2)
(modified) flang/test/Lower/OpenMP/target.f90 (+1-1)
(modified) flang/test/Parser/OpenMP/declare-mapper-unparse.f90 (+1-1)
(modified) flang/test/Parser/OpenMP/openmp6-directive-spellings.f90 (+1-1)
(modified) flang/test/Semantics/OpenMP/declare-mapper-symbols.f90 (+1-1)
(modified) llvm/include/llvm/Frontend/OpenMP/OMPConstants.h (+1-1)

diff --git a/flang/lib/Lower/OpenMP/ClauseProcessor.cpp b/flang/lib/Lower/OpenMP/ClauseProcessor.cpp
index e018a2d937435..4a392381287d5 100644
--- a/flang/lib/Lower/OpenMP/ClauseProcessor.cpp
+++ b/flang/lib/Lower/OpenMP/ClauseProcessor.cpp
@@ -1278,7 +1278,8 @@ void ClauseProcessor::processMapObjects(
     std::string mapperIdName =
         typeSpec->name().ToString() + llvm::omp::OmpDefaultMapperName;
     if (auto *sym = converter.getCurrentScope().FindSymbol(mapperIdName)) {
-      mapperIdName = converter.mangleName(mapperIdName, sym->owner());
+      mapperIdName =
+          converter.mangleName(mapperIdName, sym->GetUltimate().owner());
     } else {
       mapperIdName = converter.mangleName(mapperIdName, *typeSpec->GetScope());
     }
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index c3f670c62da06..4ebf2c7764cf3 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -2612,8 +2612,8 @@ genTargetOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
               typeSpec->name().ToString() + llvm::omp::OmpDefaultMapperName;
           if (auto *mapperSym =
                   converter.getCurrentScope().FindSymbol(mapperIdName))
-            mapperIdName =
-                converter.mangleName(mapperIdName, mapperSym->owner());
+            mapperIdName = converter.mangleName(
+                mapperIdName, mapperSym->GetUltimate().owner());
           else
             mapperIdName =
                 converter.mangleName(mapperIdName, *typeSpec->GetScope());
diff --git a/flang/test/Lower/OpenMP/declare-mapper.f90 b/flang/test/Lower/OpenMP/declare-mapper.f90
index 0266365cf03c0..a24d6bd0bf946 100644
--- a/flang/test/Lower/OpenMP/declare-mapper.f90
+++ b/flang/test/Lower/OpenMP/declare-mapper.f90
@@ -9,6 +9,8 @@
 ! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 %t/omp-declare-mapper-6.f90 -o - | FileCheck %t/omp-declare-mapper-6.f90
 ! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -module-dir %t %t/omp-declare-mapper-7.mod.f90 -o - >/dev/null
 ! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -J %t %t/omp-declare-mapper-7.use.f90 -o - | FileCheck %t/omp-declare-mapper-7.use.f90
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -module-dir %t %t/omp-declare-mapper-8.mod.f90 -o - >/dev/null
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -J %t %t/omp-declare-mapper-8.use.f90 -o - | FileCheck %t/omp-declare-mapper-8.use.f90
 
 !--- omp-declare-mapper-1.f90
 subroutine declare_mapper_1
@@ -26,7 +28,7 @@ subroutine declare_mapper_1
    end type
    type(my_type2)        :: t
    real                   :: x, y(nvals)
-   !CHECK:omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_1my_type\.omp\.default\.mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_1Tmy_type\{num_vals:i32,values:!fir\.box<!fir\.heap<!fir\.array<\?xi32>>>\}>]] {
+   !CHECK:omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_1my_type_omp_default_mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_1Tmy_type\{num_vals:i32,values:!fir\.box<!fir\.heap<!fir\.array<\?xi32>>>\}>]] {
    !CHECK:      ^bb0(%[[VAL_0:.*]]: !fir.ref<[[MY_TYPE]]>):
    !CHECK:        %[[VAL_1:.*]]:2 = hlfir.declare %[[VAL_0]] {uniq_name = "_QFdeclare_mapper_1Evar"} : (!fir.ref<[[MY_TYPE]]>) -> (!fir.ref<[[MY_TYPE]]>, !fir.ref<[[MY_TYPE]]>)
    !CHECK:        %[[VAL_2:.*]] = hlfir.designate %[[VAL_1]]#0{"values"}   {fortran_attrs = #fir.var_attrs<allocatable>} : (!fir.ref<[[MY_TYPE]]>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
@@ -153,7 +155,7 @@ subroutine declare_mapper_4
       integer              :: num
    end type
 
-   !CHECK: omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_4my_type.omp.default.mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_4Tmy_type\{num:i32\}>]]
+   !CHECK: omp.declare_mapper @[[MY_TYPE_MAPPER:_QQFdeclare_mapper_4my_type_omp_default_mapper]] : [[MY_TYPE:!fir\.type<_QFdeclare_mapper_4Tmy_type\{num:i32\}>]]
    !$omp declare mapper (my_type :: var) map (var%num)
 
    type(my_type) :: a
@@ -185,9 +187,9 @@ program declare_mapper_5
    end type
 
    !CHECK: omp.declare_mapper @[[INNER_MAPPER_NAMED:_QQFFuse_innermy_mapper]] : [[MY_TYPE:!fir\.type<_QFTmytype\{x:i32,y:i32\}>]]
-   !CHECK: omp.declare_mapper @[[INNER_MAPPER_DEFAULT:_QQFFuse_innermytype.omp.default.mapper]] : [[MY_TYPE]]
+   !CHECK: omp.declare_mapper @[[INNER_MAPPER_DEFAULT:_QQFFuse_innermytype_omp_default_mapper]] : [[MY_TYPE]]
    !CHECK: omp.declare_mapper @[[OUTER_MAPPER_NAMED:_QQFmy_mapper]] : [[MY_TYPE]]
-   !CHECK: omp.declare_mapper @[[OUTER_MAPPER_DEFAULT:_QQFmytype.omp.default.mapper]] : [[MY_TYPE]]
+   !CHECK: omp.declare_mapper @[[OUTER_MAPPER_DEFAULT:_QQFmytype_omp_default_mapper]] : [[MY_TYPE]]
    !$omp declare mapper(mytype :: var) map(tofrom: var%x)
    !$omp declare mapper(my_mapper : mytype :: var) map(tofrom: var%y)
 
@@ -325,3 +327,36 @@ program use_module_mapper
     a%x = 42
   !$omp end target
 end program use_module_mapper
+
+!--- omp-declare-mapper-8.mod.f90
+! Module with a default DECLARE MAPPER to be compiled separately.
+module default_mapper_mod
+  implicit none
+  type :: dtype
+    integer :: x
+  end type dtype
+  !$omp declare mapper(dtype :: v) map(tofrom: v%x)
+end module default_mapper_mod
+
+!--- omp-declare-mapper-8.use.f90
+! Consumer program that USEs the module and relies on the default mapper.
+! CHECK: omp.declare_mapper @{{.*dtype_omp_default_mapper}} : !fir.type<_QMdefault_mapper_modTdtype{x:i32}>
+! CHECK: %{{.*}} = omp.map.info {{.*}} map_clauses(tofrom) {{.*}} mapper(@{{.*dtype_omp_default_mapper}}) {{.*}} {name = "a"}
+! CHECK: %{{.*}} = omp.map.info {{.*}} map_clauses(tofrom) {{.*}} mapper(@{{.*dtype_omp_default_mapper}}) {{.*}} {name = "a"}
+! CHECK: %{{.*}} = omp.map.info {{.*}} map_clauses(implicit, tofrom) {{.*}} mapper(@{{.*dtype_omp_default_mapper}}) {{.*}} {name = "a"}
+program use_module_default_mapper
+  use default_mapper_mod
+  implicit none
+  type(dtype) :: a
+  !$omp target map(a)
+    a%x = 7
+  !$omp end target
+
+  !$omp target map(mapper(default) : a)
+    a%x = 8
+  !$omp end target
+
+  !$omp target
+    a%x = 8
+  !$omp end target
+end program use_module_default_mapper
diff --git a/flang/test/Lower/OpenMP/derived-type-map.f90 b/flang/test/Lower/OpenMP/derived-type-map.f90
index 228e86d9e4dfd..921dd5663f8c5 100644
--- a/flang/test/Lower/OpenMP/derived-type-map.f90
+++ b/flang/test/Lower/OpenMP/derived-type-map.f90
@@ -1,6 +1,6 @@
 !RUN: %flang_fc1 -emit-hlfir -fopenmp %s -o - | FileCheck %s
 
-!CHECK: omp.declare_mapper @[[MAPPER1:_QQFmaptype_derived_implicit_allocatablescalar_and_array.omp.default.mapper]] : !fir.type<_QFmaptype_derived_implicit_allocatableTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}> {
+!CHECK: omp.declare_mapper @[[MAPPER1:_QQFmaptype_derived_implicit_allocatablescalar_and_array_omp_default_mapper]] : !fir.type<_QFmaptype_derived_implicit_allocatableTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}> {
 
 !CHECK: %[[ALLOCA:.*]] = fir.alloca !fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}> {bindc_name = "scalar_arr", uniq_name = "_QFmaptype_derived_implicitEscalar_arr"}
 !CHECK: %[[DECLARE:.*]]:2 = hlfir.declare %[[ALLOCA]] {uniq_name = "_QFmaptype_derived_implicitEscalar_arr"} : (!fir.ref<!fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}>>) -> (!fir.ref<!fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}>>, !fir.ref<!fir.type<_QFmaptype_derived_implicitTscalar_and_array{real:f32,array:!fir.array<10xi32>,int:i32}>>)
diff --git a/flang/test/Lower/OpenMP/map-mapper.f90 b/flang/test/Lower/OpenMP/map-mapper.f90
index 91564bfc7bc46..8934fbb5d6edf 100644
--- a/flang/test/Lower/OpenMP/map-mapper.f90
+++ b/flang/test/Lower/OpenMP/map-mapper.f90
@@ -8,7 +8,7 @@ program p
    !$omp declare mapper(xx : t1 :: nn) map(to: nn, nn%x)
    !$omp declare mapper(t1 :: nn) map(from: nn)
 
-   !CHECK-LABEL: omp.declare_mapper @_QQFt1.omp.default.mapper : !fir.type<_QFTt1{x:!fir.array<256xi32>}>
+   !CHECK-LABEL: omp.declare_mapper @_QQFt1_omp_default_mapper : !fir.type<_QFTt1{x:!fir.array<256xi32>}>
    !CHECK-LABEL: omp.declare_mapper @_QQFxx : !fir.type<_QFTt1{x:!fir.array<256xi32>}>
 
    type(t1) :: a, b
@@ -20,7 +20,7 @@ program p
    end do
    !$omp end target
 
-   !CHECK: %[[MAP_B:.*]] = omp.map.info var_ptr(%{{.*}} : {{.*}}, {{.*}}) map_clauses(tofrom) capture(ByRef) mapper(@_QQFt1.omp.default.mapper) -> {{.*}} {name = "b"}
+   !CHECK: %[[MAP_B:.*]] = omp.map.info var_ptr(%{{.*}} : {{.*}}, {{.*}}) map_clauses(tofrom) capture(ByRef) mapper(@_QQFt1_omp_default_mapper) -> {{.*}} {name = "b"}
    !CHECK: omp.target map_entries(%[[MAP_B]] -> %{{.*}}, %{{.*}} -> %{{.*}} : {{.*}}, {{.*}}) {
    !$omp target map(mapper(default) : b)
    do i = 1, n
diff --git a/flang/test/Lower/OpenMP/target.f90 b/flang/test/Lower/OpenMP/target.f90
index 94907ba3ae74a..7cd642bcf23cf 100644
--- a/flang/test/Lower/OpenMP/target.f90
+++ b/flang/test/Lower/OpenMP/target.f90
@@ -529,7 +529,7 @@ subroutine omp_target_device_ptr
    use iso_c_binding, only : c_ptr, c_loc
    type(c_ptr) :: a
    integer, target :: b
-   !CHECK: %[[MAP:.*]] = omp.map.info var_ptr({{.*}})   map_clauses(tofrom) capture(ByRef) mapper(@[[CPTR_DEFAULT:_QQM__fortran_builtinsc_ptr\.omp\.default\.mapper]]) -> {{.*}} {name = "a"}
+   !CHECK: %[[MAP:.*]] = omp.map.info var_ptr({{.*}})   map_clauses(tofrom) capture(ByRef) mapper(@[[CPTR_DEFAULT:_QQM__fortran_builtinsc_ptr_omp_default_mapper]]) -> {{.*}} {name = "a"}
    !CHECK: omp.target_data map_entries(%[[MAP]]{{.*}}) use_device_ptr({{.*}} -> %[[VAL_1:.*]] : !fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>)
    !$omp target data map(tofrom: a) use_device_ptr(a)
    !CHECK: {{.*}} = fir.coordinate_of %[[VAL_1:.*]], __address : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>) -> !fir.ref<i64>
diff --git a/flang/test/Parser/OpenMP/declare-mapper-unparse.f90 b/flang/test/Parser/OpenMP/declare-mapper-unparse.f90
index b53bf5ce10557..9da6674c3a58d 100644
--- a/flang/test/Parser/OpenMP/declare-mapper-unparse.f90
+++ b/flang/test/Parser/OpenMP/declare-mapper-unparse.f90
@@ -29,7 +29,7 @@ program main
 
 !PARSE-TREE:      OpenMPDeclareMapperConstruct
 !PARSE-TREE:        OmpMapperSpecifier
-!PARSE-TREE:         string = 'ty.omp.default.mapper'
+!PARSE-TREE:         string = 'ty_omp_default_mapper'
 !PARSE-TREE:         TypeSpec -> DerivedTypeSpec
 !PARSE-TREE:           Name = 'ty'
 !PARSE-TREE:         Name = 'mapped'
diff --git a/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90 b/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90
index 50a38c6494aa6..7a627913f9555 100644
--- a/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90
+++ b/flang/test/Parser/OpenMP/openmp6-directive-spellings.f90
@@ -57,7 +57,7 @@ subroutine f01
 !PARSE-TREE: DeclarationConstruct -> SpecificationConstruct -> OpenMPDeclarativeConstruct -> OpenMPDeclareMapperConstruct -> OmpDirectiveSpecification
 !PARSE-TREE: | OmpDirectiveName -> llvm::omp::Directive = declare mapper
 !PARSE-TREE: | OmpArgumentList -> OmpArgument -> OmpMapperSpecifier
-!PARSE-TREE: | | string = 't.omp.default.mapper'
+!PARSE-TREE: | | string = 't_omp_default_mapper'
 !PARSE-TREE: | | TypeSpec -> DerivedTypeSpec
 !PARSE-TREE: | | | Name = 't'
 !PARSE-TREE: | | Name = 'v'
diff --git a/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90 b/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
index 5d77540aa6453..9a1b86758357f 100644
--- a/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
+++ b/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
@@ -13,7 +13,7 @@ program main
 !! Note, symbols come out in their respective scope, but not in declaration order.
 !CHECK: mymapper: MapperDetails
 !CHECK: ty: DerivedType components: x
-!CHECK: ty.omp.default.mapper: MapperDetails
+!CHECK: ty_omp_default_mapper: MapperDetails
 !CHECK: DerivedType scope: ty
 !CHECK: OtherConstruct scope:
 !CHECK: mapped (OmpMapToFrom) {{.*}} ObjectEntity type: TYPE(ty)
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h b/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h
index 1ac9ac040468c..58fd8a490c04a 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h
+++ b/llvm/include/llvm/Frontend/OpenMP/OMPConstants.h
@@ -201,7 +201,7 @@ enum class OMPDynGroupprivateFallbackType : uint64_t {
 };
 
 // Default OpenMP mapper name suffix.
-inline constexpr const char *OmpDefaultMapperName = ".omp.default.mapper";
+inline constexpr const char *OmpDefaultMapperName = "_omp_default_mapper";
 
 /// Values for bit flags used to specify the mapping type for
 /// offloading.

Copilot

Pull Request Overview

This PR fixes a Fortran syntax violation in the OpenMP default mapper naming convention. The suffix .omp.default.mapper contains dots which are invalid in Fortran identifiers, causing failures when mappers are written to and read from module files. The fix changes the suffix to _omp_default_mapper which uses underscores instead of dots, complying with Fortran syntax rules.

Key changes:

Changed OmpDefaultMapperName constant from .omp.default.mapper to _omp_default_mapper
Added GetUltimate() calls in mapper symbol resolution to properly handle symbols across module boundaries
Added new test case verifying default mappers work correctly when defined in a module and used in consuming programs

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

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File	Description
llvm/include/llvm/Frontend/OpenMP/OMPConstants.h	Updated the `OmpDefaultMapperName` constant to use underscores instead of dots
flang/test/Semantics/OpenMP/declare-mapper-symbols.f90	Updated test expectation to match new mapper name format
flang/test/Parser/OpenMP/openmp6-directive-spellings.f90	Updated parse tree expectation for default mapper naming
flang/test/Parser/OpenMP/declare-mapper-unparse.f90	Updated parse tree expectation for default mapper naming
flang/test/Lower/OpenMP/target.f90	Updated CHECK pattern for default mapper references
flang/test/Lower/OpenMP/map-mapper.f90	Updated CHECK patterns for default mapper declaration and usage
flang/test/Lower/OpenMP/derived-type-map.f90	Updated CHECK pattern for implicit default mapper
flang/test/Lower/OpenMP/declare-mapper.f90	Updated all CHECK patterns and added comprehensive new test (omp-declare-mapper-8) for module file scenario
flang/lib/Lower/OpenMP/OpenMP.cpp	Added `GetUltimate()` call when resolving mapper symbols for proper cross-module symbol resolution
flang/lib/Lower/OpenMP/ClauseProcessor.cpp	Added `GetUltimate()` call when resolving mapper symbols for proper cross-module symbol resolution

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TIFitis requested review from Copilot, kiranchandramohan and kparzysz November 17, 2025 16:31

llvmbot added flang Flang issues not falling into any other category flang:fir-hlfir flang:openmp flang:semantics flang:parser clang:openmp OpenMP related changes to Clang labels Nov 17, 2025

Copilot started reviewing on behalf of TIFitis November 17, 2025 16:32 View session

Copilot finished reviewing on behalf of TIFitis November 17, 2025 16:34

Copilot AI reviewed Nov 17, 2025

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kparzysz approved these changes Nov 17, 2025

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TIFitis enabled auto-merge (squash) November 17, 2025 17:03

TIFitis merged commit 8c674f0 into llvm:main Nov 17, 2025
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[OpenMP][Flang] Change the OmpDefaultMapperName suffix #168399

[OpenMP][Flang] Change the OmpDefaultMapperName suffix #168399

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[OpenMP][Flang] Change the OmpDefaultMapperName suffix #168399

[OpenMP][Flang] Change the OmpDefaultMapperName suffix #168399

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TIFitis commented Nov 17, 2025 •

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