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

This patch implements the parsing and sema support for the OpenMP
'from'-clause with potential user-defined mappers attached.
User-defined mappers are a new feature in OpenMP 5.0. A '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 from(mapper(id): ss) // use the mapper with name 'id' to map ss from device

Contributed-by: Lingda Li <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D58638

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@354817 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 115 insertions, 62 deletions

diff --git a/lib/AST/OpenMPClause.cpp b/lib/AST/OpenMPClause.cpp
index 0f1cb0258a..b02a888a8c 100644
--- a/lib/AST/OpenMPClause.cpp
+++ b/lib/AST/OpenMPClause.cpp
@@ -892,10 +892,11 @@ OMPToClause *OMPToClause::CreateEmpty(const ASTContext &C,
   return new (Mem) OMPToClause(Sizes);
 }
 
-OMPFromClause *
-OMPFromClause::Create(const ASTContext &C, const OMPVarListLocTy &Locs,
-                      ArrayRef<Expr *> Vars, ArrayRef<ValueDecl *> Declarations,
-                      MappableExprComponentListsRef ComponentLists) {
+OMPFromClause *OMPFromClause::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);
@@ -903,8 +904,8 @@ OMPFromClause::Create(const ASTContext &C, const OMPVarListLocTy &Locs,
   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
@@ -915,13 +916,15 @@ OMPFromClause::Create(const ASTContext &C, const OMPVarListLocTy &Locs,
   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));
 
-  OMPFromClause *Clause = new (Mem) OMPFromClause(Locs, Sizes);
+  auto *Clause =
+      new (Mem) OMPFromClause(UDMQualifierLoc, MapperId, Locs, Sizes);
 
   Clause->setVarRefs(Vars);
+  Clause->setUDMapperRefs(UDMapperRefs);
   Clause->setClauseInfo(Declarations, ComponentLists);
   return Clause;
 }
@@ -932,7 +935,7 @@ OMPFromClause::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) OMPFromClause(Sizes);
@@ -1465,7 +1468,19 @@ void OMPClausePrinter::VisitOMPToClause(OMPToClause *Node) {
 void OMPClausePrinter::VisitOMPFromClause(OMPFromClause *Node) {
   if (!Node->varlist_empty()) {
     OS << "from";
-    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 << ")";
   }
 }
diff --git a/lib/Basic/OpenMPKinds.cpp b/lib/Basic/OpenMPKinds.cpp
index 47830c324d..b10c6d2498 100644
--- a/lib/Basic/OpenMPKinds.cpp
+++ b/lib/Basic/OpenMPKinds.cpp
@@ -122,6 +122,12 @@ unsigned clang::getOpenMPSimpleClauseType(OpenMPClauseKind Kind,
   .Case(#Name, static_cast<unsigned>(OMPC_TO_MODIFIER_##Name))
 #include "clang/Basic/OpenMPKinds.def"
         .Default(OMPC_TO_MODIFIER_unknown);
+  case OMPC_from:
+    return llvm::StringSwitch<unsigned>(Str)
+#define OPENMP_FROM_MODIFIER_KIND(Name)                                     \
+  .Case(#Name, static_cast<unsigned>(OMPC_FROM_MODIFIER_##Name))
+#include "clang/Basic/OpenMPKinds.def"
+        .Default(OMPC_FROM_MODIFIER_unknown);
   case OMPC_dist_schedule:
     return llvm::StringSwitch<OpenMPDistScheduleClauseKind>(Str)
 #define OPENMP_DIST_SCHEDULE_KIND(Name) .Case(#Name, OMPC_DIST_SCHEDULE_##Name)
@@ -180,7 +186,6 @@ unsigned clang::getOpenMPSimpleClauseType(OpenMPClauseKind Kind,
   case OMPC_num_tasks:
   case OMPC_hint:
   case OMPC_uniform:
-  case OMPC_from:
   case OMPC_use_device_ptr:
   case OMPC_is_device_ptr:
   case OMPC_unified_address:
@@ -277,6 +282,18 @@ const char *clang::getOpenMPSimpleClauseTypeName(OpenMPClauseKind Kind,
       break;
     }
     llvm_unreachable("Invalid OpenMP 'to' clause type");
+  case OMPC_from:
+    switch (Type) {
+    case OMPC_FROM_MODIFIER_unknown:
+      return "unknown";
+#define OPENMP_FROM_MODIFIER_KIND(Name)                                        \
+  case OMPC_FROM_MODIFIER_##Name:                                              \
+    return #Name;
+#include "clang/Basic/OpenMPKinds.def"
+    default:
+      break;
+    }
+    llvm_unreachable("Invalid OpenMP 'from' clause type");
   case OMPC_dist_schedule:
     switch (Type) {
     case OMPC_DIST_SCHEDULE_unknown:
@@ -350,7 +367,6 @@ const char *clang::getOpenMPSimpleClauseTypeName(OpenMPClauseKind Kind,
   case OMPC_num_tasks:
   case OMPC_hint:
   case OMPC_uniform:
-  case OMPC_from:
   case OMPC_use_device_ptr:
   case OMPC_is_device_ptr:
   case OMPC_unified_address:
diff --git a/lib/Parse/ParseOpenMP.cpp b/lib/Parse/ParseOpenMP.cpp
index 68843f0c65..782ad12aac 100644
--- a/lib/Parse/ParseOpenMP.cpp
+++ b/lib/Parse/ParseOpenMP.cpp
@@ -2161,13 +2161,20 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
 
     if (Tok.is(tok::colon))
       Data.ColonLoc = ConsumeToken();
-  } else if (Kind == OMPC_to) {
+  } else if (Kind == OMPC_to || Kind == OMPC_from) {
     if (Tok.is(tok::identifier)) {
       bool IsMapperModifier = false;
-      auto Modifier = static_cast<OpenMPToModifierKind>(
-          getOpenMPSimpleClauseType(Kind, PP.getSpelling(Tok)));
-      if (Modifier == OMPC_TO_MODIFIER_mapper)
-        IsMapperModifier = true;
+      if (Kind == OMPC_to) {
+        auto Modifier = static_cast<OpenMPToModifierKind>(
+            getOpenMPSimpleClauseType(Kind, PP.getSpelling(Tok)));
+        if (Modifier == OMPC_TO_MODIFIER_mapper)
+          IsMapperModifier = true;
+      } else {
+        auto Modifier = static_cast<OpenMPFromModifierKind>(
+            getOpenMPSimpleClauseType(Kind, PP.getSpelling(Tok)));
+        if (Modifier == OMPC_FROM_MODIFIER_mapper)
+          IsMapperModifier = true;
+      }
       if (IsMapperModifier) {
         // Parse the mapper modifier.
         ConsumeToken();
@@ -2282,7 +2289,7 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
 ///    to-clause:
 ///       'to' '(' [ mapper '(' mapper-identifier ')' ':' ] list ')'
 ///    from-clause:
-///       'from' '(' list ')'
+///       'from' '(' [ mapper '(' mapper-identifier ')' ':' ] list ')'
 ///    use_device_ptr-clause:
 ///       'use_device_ptr' '(' list ')'
 ///    is_device_ptr-clause:
diff --git a/lib/Sema/SemaOpenMP.cpp b/lib/Sema/SemaOpenMP.cpp
index 5a6891d01a..76141afd59 100644
--- a/lib/Sema/SemaOpenMP.cpp
+++ b/lib/Sema/SemaOpenMP.cpp
@@ -9806,7 +9806,8 @@ OMPClause *Sema::ActOnOpenMPVarListClause(
                               ReductionOrMapperId, Locs);
     break;
   case OMPC_from:
-    Res = ActOnOpenMPFromClause(VarList, Locs);
+    Res = ActOnOpenMPFromClause(VarList, ReductionOrMapperIdScopeSpec,
+                                ReductionOrMapperId, Locs);
     break;
   case OMPC_use_device_ptr:
     Res = ActOnOpenMPUseDevicePtrClause(VarList, Locs);
@@ -13190,15 +13191,13 @@ static void checkMappableExpressionList(
     if (VE->isValueDependent() || VE->isTypeDependent() ||
         VE->isInstantiationDependent() ||
         VE->containsUnexpandedParameterPack()) {
-      if (CKind != OMPC_from) {
-        // Try to find the associated user-defined mapper.
-        ExprResult ER = buildUserDefinedMapperRef(
-            SemaRef, DSAS->getCurScope(), MapperIdScopeSpec, MapperId,
-            VE->getType().getCanonicalType(), UnresolvedMapper);
-        if (ER.isInvalid())
-          continue;
-        MVLI.UDMapperList.push_back(ER.get());
-      }
+      // Try to find the associated user-defined mapper.
+      ExprResult ER = buildUserDefinedMapperRef(
+          SemaRef, DSAS->getCurScope(), MapperIdScopeSpec, MapperId,
+          VE->getType().getCanonicalType(), UnresolvedMapper);
+      if (ER.isInvalid())
+        continue;
+      MVLI.UDMapperList.push_back(ER.get());
       // We can only analyze this information once the missing information is
       // resolved.
       MVLI.ProcessedVarList.push_back(RE);
@@ -13230,15 +13229,13 @@ static void checkMappableExpressionList(
     if (const auto *TE = dyn_cast<CXXThisExpr>(BE)) {
       // Add store "this" pointer to class in DSAStackTy for future checking
       DSAS->addMappedClassesQualTypes(TE->getType());
-      if (CKind != OMPC_from) {
-        // Try to find the associated user-defined mapper.
-        ExprResult ER = buildUserDefinedMapperRef(
-            SemaRef, DSAS->getCurScope(), MapperIdScopeSpec, MapperId,
-            VE->getType().getCanonicalType(), UnresolvedMapper);
-        if (ER.isInvalid())
-          continue;
-        MVLI.UDMapperList.push_back(ER.get());
-      }
+      // Try to find the associated user-defined mapper.
+      ExprResult ER = buildUserDefinedMapperRef(
+          SemaRef, DSAS->getCurScope(), MapperIdScopeSpec, MapperId,
+          VE->getType().getCanonicalType(), UnresolvedMapper);
+      if (ER.isInvalid())
+        continue;
+      MVLI.UDMapperList.push_back(ER.get());
       // Skip restriction checking for variable or field declarations
       MVLI.ProcessedVarList.push_back(RE);
       MVLI.VarComponents.resize(MVLI.VarComponents.size() + 1);
@@ -13358,14 +13355,12 @@ static void checkMappableExpressionList(
     }
 
     // Try to find the associated user-defined mapper.
-    if (CKind != OMPC_from) {
-      ExprResult ER = buildUserDefinedMapperRef(
-          SemaRef, DSAS->getCurScope(), MapperIdScopeSpec, MapperId,
-          Type.getCanonicalType(), UnresolvedMapper);
-      if (ER.isInvalid())
-        continue;
-      MVLI.UDMapperList.push_back(ER.get());
-    }
+    ExprResult ER = buildUserDefinedMapperRef(
+        SemaRef, DSAS->getCurScope(), MapperIdScopeSpec, MapperId,
+        Type.getCanonicalType(), UnresolvedMapper);
+    if (ER.isInvalid())
+      continue;
+    MVLI.UDMapperList.push_back(ER.get());
 
     // Save the current expression.
     MVLI.ProcessedVarList.push_back(RE);
@@ -14182,18 +14177,20 @@ OMPClause *Sema::ActOnOpenMPToClause(ArrayRef<Expr *> VarList,
 }
 
 OMPClause *Sema::ActOnOpenMPFromClause(ArrayRef<Expr *> VarList,
-                                       const OMPVarListLocTy &Locs) {
+                                       CXXScopeSpec &MapperIdScopeSpec,
+                                       DeclarationNameInfo &MapperId,
+                                       const OMPVarListLocTy &Locs,
+                                       ArrayRef<Expr *> UnresolvedMappers) {
   MappableVarListInfo MVLI(VarList);
-  CXXScopeSpec MapperIdScopeSpec;
-  DeclarationNameInfo MapperId;
-  ArrayRef<Expr *> UnresolvedMappers;
   checkMappableExpressionList(*this, DSAStack, OMPC_from, MVLI, Locs.StartLoc,
                               MapperIdScopeSpec, MapperId, UnresolvedMappers);
   if (MVLI.ProcessedVarList.empty())
     return nullptr;
 
-  return OMPFromClause::Create(Context, Locs, MVLI.ProcessedVarList,
-                               MVLI.VarBaseDeclarations, MVLI.VarComponents);
+  return OMPFromClause::Create(
+      Context, Locs, MVLI.ProcessedVarList, MVLI.VarBaseDeclarations,
+      MVLI.VarComponents, MVLI.UDMapperList,
+      MapperIdScopeSpec.getWithLocInContext(Context), MapperId);
 }
 
 OMPClause *Sema::ActOnOpenMPUseDevicePtrClause(ArrayRef<Expr *> VarList,
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index b8f922a76e..386b23db3a 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -1915,8 +1915,12 @@ public:
   /// By default, performs semantic analysis to build the new statement.
   /// Subclasses may override this routine to provide different behavior.
   OMPClause *RebuildOMPFromClause(ArrayRef<Expr *> VarList,
-                                  const OMPVarListLocTy &Locs) {
-    return getSema().ActOnOpenMPFromClause(VarList, Locs);
+                                  CXXScopeSpec &MapperIdScopeSpec,
+                                  DeclarationNameInfo &MapperId,
+                                  const OMPVarListLocTy &Locs,
+                                  ArrayRef<Expr *> UnresolvedMappers) {
+    return getSema().ActOnOpenMPFromClause(VarList, MapperIdScopeSpec, MapperId,
+                                           Locs, UnresolvedMappers);
   }
 
   /// Build a new OpenMP 'use_device_ptr' clause.
@@ -8976,16 +8980,16 @@ OMPClause *TreeTransform<Derived>::TransformOMPToClause(OMPToClause *C) {
 
 template <typename Derived>
 OMPClause *TreeTransform<Derived>::TransformOMPFromClause(OMPFromClause *C) {
-  llvm::SmallVector<Expr *, 16> Vars;
-  Vars.reserve(C->varlist_size());
-  for (auto *VE : C->varlists()) {
-    ExprResult EVar = getDerived().TransformExpr(cast<Expr>(VE));
-    if (EVar.isInvalid())
-      return 0;
-    Vars.push_back(EVar.get());
-  }
   OMPVarListLocTy Locs(C->getBeginLoc(), C->getLParenLoc(), C->getEndLoc());
-  return getDerived().RebuildOMPFromClause(Vars, Locs);
+  llvm::SmallVector<Expr *, 16> Vars;
+  CXXScopeSpec MapperIdScopeSpec;
+  DeclarationNameInfo MapperIdInfo;
+  llvm::SmallVector<Expr *, 16> UnresolvedMappers;
+  if (transformOMPMappableExprListClause<Derived, OMPFromClause>(
+          *this, C, Vars, MapperIdScopeSpec, MapperIdInfo, UnresolvedMappers))
+    return nullptr;
+  return getDerived().RebuildOMPFromClause(
+      Vars, MapperIdScopeSpec, MapperIdInfo, Locs, UnresolvedMappers);
 }
 
 template <typename Derived>
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index bed58d0e10..9626418f68 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -12448,6 +12448,10 @@ void OMPClauseReader::VisitOMPToClause(OMPToClause *C) {
 
 void OMPClauseReader::VisitOMPFromClause(OMPFromClause *C) {
   C->setLParenLoc(Record.readSourceLocation());
+  C->setMapperQualifierLoc(Record.readNestedNameSpecifierLoc());
+  DeclarationNameInfo DNI;
+  Record.readDeclarationNameInfo(DNI);
+  C->setMapperIdInfo(DNI);
   auto NumVars = C->varlist_size();
   auto UniqueDecls = C->getUniqueDeclarationsNum();
   auto TotalLists = C->getTotalComponentListNum();
@@ -12459,6 +12463,12 @@ void OMPClauseReader::VisitOMPFromClause(OMPFromClause *C) {
     Vars.push_back(Record.readSubExpr());
   C->setVarRefs(Vars);
 
+  SmallVector<Expr *, 16> UDMappers;
+  UDMappers.reserve(NumVars);
+  for (unsigned I = 0; I < NumVars; ++I)
+    UDMappers.push_back(Record.readSubExpr());
+  C->setUDMapperRefs(UDMappers);
+
   SmallVector<ValueDecl *, 16> Decls;
   Decls.reserve(UniqueDecls);
   for (unsigned i = 0; i < UniqueDecls; ++i)
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 1575a400ba..3d19c9d823 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -6885,8 +6885,12 @@ void OMPClauseWriter::VisitOMPFromClause(OMPFromClause *C) {
   Record.push_back(C->getTotalComponentListNum());
   Record.push_back(C->getTotalComponentsNum());
   Record.AddSourceLocation(C->getLParenLoc());
+  Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
+  Record.AddDeclarationNameInfo(C->getMapperIdInfo());
   for (auto *E : C->varlists())
     Record.AddStmt(E);
+  for (auto *E : C->mapperlists())
+    Record.AddStmt(E);
   for (auto *D : C->all_decls())
     Record.AddDeclRef(D);
   for (auto N : C->all_num_lists())