[OpenMP 5.0] Parsing/sema support for to clause with mapper modifier.

This patch implements the parsing and sema support for OpenMP to clause
with potential user-defined mappers attached. User defined mapper is a
new feature in OpenMP 5.0. A to/from clause can have an explicit or
implicit associated mapper, which instructs the compiler to generate and
use customized mapping functions. An example is shown below:

    struct S { int len; int *d; };
    #pragma omp declare mapper(id: struct S s) map(s, s.d[0:s.len])
    struct S ss;
    #pragma omp target update to(mapper(id): ss) // use the mapper with name 'id' to map ss to device

Contributed-by: <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D58523

llvm-svn: 354698

1 files changed, 24 insertions, 11 deletions

diff --git a/clang/lib/AST/OpenMPClause.cpp b/clang/lib/AST/OpenMPClause.cpp
index 549b869849d..0f1cb0258a6 100644
--- a/clang/lib/AST/OpenMPClause.cpp
+++ b/clang/lib/AST/OpenMPClause.cpp
@@ -845,11 +845,11 @@ OMPMapClause::CreateEmpty(const ASTContext &C,
   return new (Mem) OMPMapClause(Sizes);
 }
 
-OMPToClause *OMPToClause::Create(const ASTContext &C,
-                                 const OMPVarListLocTy &Locs,
-                                 ArrayRef<Expr *> Vars,
-                                 ArrayRef<ValueDecl *> Declarations,
-                                 MappableExprComponentListsRef ComponentLists) {
+OMPToClause *OMPToClause::Create(
+    const ASTContext &C, const OMPVarListLocTy &Locs, ArrayRef<Expr *> Vars,
+    ArrayRef<ValueDecl *> Declarations,
+    MappableExprComponentListsRef ComponentLists, ArrayRef<Expr *> UDMapperRefs,
+    NestedNameSpecifierLoc UDMQualifierLoc, DeclarationNameInfo MapperId) {
   OMPMappableExprListSizeTy Sizes;
   Sizes.NumVars = Vars.size();
   Sizes.NumUniqueDeclarations = getUniqueDeclarationsTotalNumber(Declarations);
@@ -857,8 +857,8 @@ OMPToClause *OMPToClause::Create(const ASTContext &C,
   Sizes.NumComponents = getComponentsTotalNumber(ComponentLists);
 
   // We need to allocate:
-  // NumVars x Expr* - we have an original list expression for each clause list
-  // entry.
+  // 2 x NumVars x Expr* - we have an original list expression and an associated
+  // user-defined mapper for each clause list entry.
   // NumUniqueDeclarations x ValueDecl* - unique base declarations associated
   // with each component list.
   // (NumUniqueDeclarations + NumComponentLists) x unsigned - we specify the
@@ -869,13 +869,14 @@ OMPToClause *OMPToClause::Create(const ASTContext &C,
   void *Mem = C.Allocate(
       totalSizeToAlloc<Expr *, ValueDecl *, unsigned,
                        OMPClauseMappableExprCommon::MappableComponent>(
-          Sizes.NumVars, Sizes.NumUniqueDeclarations,
+          2 * Sizes.NumVars, Sizes.NumUniqueDeclarations,
           Sizes.NumUniqueDeclarations + Sizes.NumComponentLists,
           Sizes.NumComponents));
 
-  OMPToClause *Clause = new (Mem) OMPToClause(Locs, Sizes);
+  auto *Clause = new (Mem) OMPToClause(UDMQualifierLoc, MapperId, Locs, Sizes);
 
   Clause->setVarRefs(Vars);
+  Clause->setUDMapperRefs(UDMapperRefs);
   Clause->setClauseInfo(Declarations, ComponentLists);
   return Clause;
 }
@@ -885,7 +886,7 @@ OMPToClause *OMPToClause::CreateEmpty(const ASTContext &C,
   void *Mem = C.Allocate(
       totalSizeToAlloc<Expr *, ValueDecl *, unsigned,
                        OMPClauseMappableExprCommon::MappableComponent>(
-          Sizes.NumVars, Sizes.NumUniqueDeclarations,
+          2 * Sizes.NumVars, Sizes.NumUniqueDeclarations,
           Sizes.NumUniqueDeclarations + Sizes.NumComponentLists,
           Sizes.NumComponents));
   return new (Mem) OMPToClause(Sizes);
@@ -1444,7 +1445,19 @@ void OMPClausePrinter::VisitOMPMapClause(OMPMapClause *Node) {
 void OMPClausePrinter::VisitOMPToClause(OMPToClause *Node) {
   if (!Node->varlist_empty()) {
     OS << "to";
-    VisitOMPClauseList(Node, '(');
+    DeclarationNameInfo MapperId = Node->getMapperIdInfo();
+    if (MapperId.getName() && !MapperId.getName().isEmpty()) {
+      OS << '(';
+      OS << "mapper(";
+      NestedNameSpecifier *MapperNNS =
+          Node->getMapperQualifierLoc().getNestedNameSpecifier();
+      if (MapperNNS)
+        MapperNNS->print(OS, Policy);
+      OS << MapperId << "):";
+      VisitOMPClauseList(Node, ' ');
+    } else {
+      VisitOMPClauseList(Node, '(');
+    }
     OS << ")";
   }
 }