[flang][OpenMP][DoConcurrent] Handle mapping non-reference values to device

Fixes a bug uncovered by Berkely Labs' inference-engine project. This
handles non-reference/non-box values (e.g. values that result from
`fir.box_dims` ops) when we need to map those values to the target
region.

Author: ergawy

flang/lib/Optimizer/OpenMP/DoConcurrentConversion.cpp

@@ -791,7 +791,7 @@ class DoConcurrentConversion : public mlir::OpConversionPattern<fir::DoLoopOp> {
 
     return Fortran::lower::omp::internal::createMapInfoOp(
         rewriter, liveIn.getLoc(), rawAddr,
-        /*varPtrPtr=*/{}, declareOp.getUniqName().str(), boundsOps,
+        /*varPtrPtr=*/{}, name.str(), boundsOps,
         /*members=*/{},
         /*membersIndex=*/mlir::ArrayAttr{},
         static_cast<
@@ -814,8 +814,8 @@ class DoConcurrentConversion : public mlir::OpConversionPattern<fir::DoLoopOp> {
     llvm::SmallVector<mlir::Type> regionArgTypes;
     llvm::SmallVector<mlir::Location> regionArgLocs;
 
-    for (auto var :
-         llvm::concat<const mlir::Value>(clauseOps.hostEvalVars, mappedVars)) {
+    for (auto var : llvm::concat<const mlir::Value>(clauseOps.hostEvalVars,
+                                                    clauseOps.mapVars)) {
       regionArgTypes.push_back(var.getType());
       regionArgLocs.push_back(var.getLoc());
     }
@@ -825,11 +825,19 @@ class DoConcurrentConversion : public mlir::OpConversionPattern<fir::DoLoopOp> {
         rewriter,
         fir::getKindMapping(targetOp->getParentOfType<mlir::ModuleOp>()));
 
-    for (auto [arg, mapInfoOp, mappedVar] : llvm::zip_equal(
-             argIface.getMapBlockArgs(), clauseOps.mapVars, mappedVars)) {
+    // Within the loop, it possible that we discover other values that need to
+    // mapped to the target region (the shape info values for arrays, for
+    // example). Therefore, the map block args might be extended and resized.
+    // Hence, we invoke `argIface.getMapBlockArgs()` every iteration to make
+    // sure we access the proper vector of data.
+    int idx = 0;
+    for (auto [mapInfoOp, mappedVar] :
+         llvm::zip_equal(clauseOps.mapVars, mappedVars)) {
       auto miOp = mlir::cast<mlir::omp::MapInfoOp>(mapInfoOp.getDefiningOp());
-      hlfir::DeclareOp liveInDeclare = genLiveInDeclare(
-          builder, targetOp, arg, miOp, liveInShapeInfoMap.at(mappedVar));
+      hlfir::DeclareOp liveInDeclare =
+          genLiveInDeclare(builder, targetOp, argIface.getMapBlockArgs()[idx],
+                           miOp, liveInShapeInfoMap.at(mappedVar));
+      ++idx;
 
       // TODO If `mappedVar.getDefiningOp()` is a `fir::BoxAddrOp`, we probably
       // need to "unpack" the box by getting the defining op of it's value.

flang/test/Transforms/DoConcurrent/non_reference_to_device.f90

@@ -0,0 +1,30 @@
+! Tests that we can map "unnamed" and non-reference/non-box values to device; for
+! example, values that result from `fix.box_dims` ops.
+
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fdo-concurrent-parallel=device %s -o - \
+! RUN:   | FileCheck %s
+! RUN: bbc -emit-hlfir -fopenmp -fdo-concurrent-parallel=device %s -o - \
+! RUN:   | FileCheck %s
+
+subroutine test_non_refernece
+  integer i
+  real, allocatable :: arr(:)
+
+  associate(a => arr)
+    do concurrent (i = 1:10)
+      block
+        real z(size(a,1))
+      end block
+    end do
+  end associate
+end subroutine test_non_refernece
+
+! CHECK:      %[[DIM_MAP:.*]] = omp.map.info var_ptr(%{{.*}} : !fir.ref<index>, index)
+! CHECK-SAME:                     map_clauses(implicit, exit_release_or_enter_alloc)
+! CHECK-SAME:                     capture(ByCopy) -> !fir.ref<index> {name = ""}
+
+
+! CHECK:      omp.target host_eval({{.*}} : index, index, index)
+! CHECK-SAME:   map_entries(%{{.*}} -> %{{.*}}, %[[DIM_MAP]] -> %{{.*}} :
+! CHECK-SAME:               !fir.ref<i32>, !fir.ref<index>)
+