[Flang][OpenMP] Update default MapType for Map Clauses and OpenMP 5.2 (#144715)

In OpenMP 5.2, the `target enter data` and `target exit data` constructs
now have default map types if the user does not define them in the Map
clause. For `target enter data`, this is `to` and `target exit data`
this is `from`. This behaviour is now enabled when OpenMP 5.2 or greater
is used when compiling. To enable this, the default value is now set in
the `processMap` clause, with any previous behaviour being maintained
for either older versions of OpenMP or other directives.

See also #110008

Author: Stylie777

flang/lib/Lower/OpenMP/ClauseProcessor.cpp

@@ -1269,7 +1269,7 @@ void ClauseProcessor::processMapObjects(
 
 bool ClauseProcessor::processMap(
     mlir::Location currentLocation, lower::StatementContext &stmtCtx,
-    mlir::omp::MapClauseOps &result,
+    mlir::omp::MapClauseOps &result, llvm::omp::Directive directive,
     llvm::SmallVectorImpl<const semantics::Symbol *> *mapSyms) const {
   // We always require tracking of symbols, even if the caller does not,
   // so we create an optionally used local set of symbols when the mapSyms
@@ -1287,9 +1287,18 @@ bool ClauseProcessor::processMap(
     llvm::omp::OpenMPOffloadMappingFlags mapTypeBits =
         llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_NONE;
     std::string mapperIdName = "__implicit_mapper";
-    // If the map type is specified, then process it else Tofrom is the
-    // default.
-    Map::MapType type = mapType.value_or(Map::MapType::Tofrom);
+    // If the map type is specified, then process it else set the appropriate
+    // default value
+    Map::MapType type;
+    if (directive == llvm::omp::Directive::OMPD_target_enter_data &&
+        semaCtx.langOptions().OpenMPVersion >= 52)
+      type = mapType.value_or(Map::MapType::To);
+    else if (directive == llvm::omp::Directive::OMPD_target_exit_data &&
+             semaCtx.langOptions().OpenMPVersion >= 52)
+      type = mapType.value_or(Map::MapType::From);
+    else
+      type = mapType.value_or(Map::MapType::Tofrom);
+
     switch (type) {
     case Map::MapType::To:
       mapTypeBits |= llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_TO;

flang/lib/Lower/OpenMP/ClauseProcessor.h

@@ -139,6 +139,7 @@ class ClauseProcessor {
   bool processMap(mlir::Location currentLocation,
                   lower::StatementContext &stmtCtx,
                   mlir::omp::MapClauseOps &result,
+                  llvm::omp::Directive directive = llvm::omp::OMPD_unknown,
                   llvm::SmallVectorImpl<const semantics::Symbol *> *mapSyms =
                       nullptr) const;
   bool processMotionClauses(lower::StatementContext &stmtCtx,

flang/lib/Lower/OpenMP/Clauses.cpp

@@ -1043,7 +1043,7 @@ Map make(const parser::OmpClause::Map &inp,
   auto type = [&]() -> std::optional<Map::MapType> {
     if (t3)
       return convert1(t3->v);
-    return Map::MapType::Tofrom;
+    return std::nullopt;
   }();
 
   Map::MapTypeModifiers typeMods;

flang/lib/Lower/OpenMP/OpenMP.cpp

@@ -1831,7 +1831,8 @@ static void genTargetClauses(
   }
   cp.processIf(llvm::omp::Directive::OMPD_target, clauseOps);
   cp.processIsDevicePtr(clauseOps, isDevicePtrSyms);
-  cp.processMap(loc, stmtCtx, clauseOps, &mapSyms);
+  cp.processMap(loc, stmtCtx, clauseOps, llvm::omp::Directive::OMPD_unknown,
+                &mapSyms);
   cp.processNowait(clauseOps);
   cp.processThreadLimit(stmtCtx, clauseOps);
 
@@ -1884,7 +1885,7 @@ static void genTargetEnterExitUpdateDataClauses(
   if (directive == llvm::omp::Directive::OMPD_target_update)
     cp.processMotionClauses(stmtCtx, clauseOps);
   else
-    cp.processMap(loc, stmtCtx, clauseOps);
+    cp.processMap(loc, stmtCtx, clauseOps, directive);
 
   cp.processNowait(clauseOps);
 }

flang/test/Lower/OpenMP/target-enter-data-default-openmp52.f90

@@ -0,0 +1,27 @@
+! This test checks the lowering and application of default map types for the target enter/exit data constructs and map clauses
+
+!RUN: %flang -fc1 -emit-fir -fopenmp -fopenmp-version=52 -o - %s | FileCheck %s --check-prefix=CHECK-52
+!RUN: not %flang -fc1 -emit-fir -fopenmp -fopenmp-version=51 -o - %s 2>&1| FileCheck %s --check-prefix=CHECK-51
+
+module test
+  real, allocatable :: A
+
+contains
+  subroutine initialize()
+  allocate(A)
+  !$omp target enter data map(A)
+  !CHECK-52: omp.map.info var_ptr(%2 : !fir.ref<!fir.box<!fir.heap<f32>>>, f32) map_clauses(to) capture(ByRef) var_ptr_ptr(%5 : !fir.llvm_ptr<!fir.ref<f32>>) -> !fir.llvm_ptr<!fir.ref<f32>> {name = ""}
+  !CHECK-52: omp.map.info var_ptr(%2 : !fir.ref<!fir.box<!fir.heap<f32>>>, !fir.box<!fir.heap<f32>>) map_clauses(to) capture(ByRef) members(%6 : [0] : !fir.llvm_ptr<!fir.ref<f32>>) -> !fir.ref<!fir.box<!fir.heap<f32>>> {name = "a"}
+  !CHECK-51: to and alloc map types are permitted
+
+  end subroutine initialize
+
+  subroutine finalize()
+  !$omp target exit data map(A)
+  !CHECK-52: omp.map.info var_ptr(%2 : !fir.ref<!fir.box<!fir.heap<f32>>>, f32) map_clauses(from) capture(ByRef) var_ptr_ptr(%3 : !fir.llvm_ptr<!fir.ref<f32>>) -> !fir.llvm_ptr<!fir.ref<f32>> {name = ""}
+  !CHECK-52: omp.map.info var_ptr(%2 : !fir.ref<!fir.box<!fir.heap<f32>>>, !fir.box<!fir.heap<f32>>) map_clauses(from) capture(ByRef) members(%4 : [0] : !fir.llvm_ptr<!fir.ref<f32>>) -> !fir.ref<!fir.box<!fir.heap<f32>>> {name = "a"}
+  !CHECK-51: from, release and delete map types are permitted
+  deallocate(A)
+  
+  end subroutine finalize
+end module test