Improve support for metadirective + declare reduction

Author: Leporacanthicus

flang/include/flang/Semantics/symbol.h

@@ -30,7 +30,7 @@ class raw_ostream;
 namespace Fortran::parser {
 struct Expr;
 struct OpenMPDeclareReductionConstruct;
-struct OmpDirectiveSpecification;
+struct OmpMetadirectiveDirective;
 }
 
 namespace Fortran::semantics {
@@ -710,7 +710,7 @@ class UserReductionDetails {
 public:
   using TypeVector = std::vector<const DeclTypeSpec *>;
   using DeclInfo = std::variant<const parser::OpenMPDeclareReductionConstruct *,
-      const parser::OmpDirectiveSpecification *>;
+      const parser::OmpMetadirectiveDirective *>;
   using DeclVector = std::vector<DeclInfo>;
 
   UserReductionDetails() = default;

flang/lib/Parser/unparse.cpp

@@ -3329,7 +3329,7 @@ template void Unparse<Expr>(llvm::raw_ostream &, const Expr &, Encoding, bool,
 template void Unparse<parser::OpenMPDeclareReductionConstruct>(
     llvm::raw_ostream &, const parser::OpenMPDeclareReductionConstruct &,
     Encoding, bool, bool, preStatementType *, AnalyzedObjectsAsFortran *);
-template void Unparse<parser::OmpDirectiveSpecification>(llvm::raw_ostream &,
-    const parser::OmpDirectiveSpecification &, Encoding, bool, bool,
+template void Unparse<parser::OmpMetadirectiveDirective>(llvm::raw_ostream &,
+    const parser::OmpMetadirectiveDirective &, Encoding, bool, bool,
     preStatementType *, AnalyzedObjectsAsFortran *);
 } // namespace Fortran::parser

flang/lib/Semantics/mod-file.cpp

@@ -1047,7 +1047,7 @@ void ModFileWriter::PutUserReduction(
     if (auto d = std::get_if<const parser::OpenMPDeclareReductionConstruct *>(
             &decl)) {
       Unparse(os, **d);
-    } else if (auto s = std::get_if<const parser::OmpDirectiveSpecification *>(
+    } else if (auto s = std::get_if<const parser::OmpMetadirectiveDirective *>(
                    &decl)) {
       Unparse(os, **s);
     } else {

flang/lib/Semantics/resolve-names.cpp

@@ -1655,6 +1655,14 @@ class OmpVisitor : public virtual DeclarationVisitor {
     EndDeclTypeSpec();
   }
 
+  bool Pre(const parser::OmpMetadirectiveDirective &x) { //
+    metaDirective_ = &x;
+    return true;
+  }
+  void Post(const parser::OmpMetadirectiveDirective &) { //
+    metaDirective_ = nullptr;
+  }
+
 private:
   void ProcessMapperSpecifier(const parser::OmpMapperSpecifier &spec,
       const parser::OmpClauseList &clauses);
@@ -1666,6 +1674,7 @@ class OmpVisitor : public virtual DeclarationVisitor {
   parser::CharBlock MangleDefinedOperator(const parser::CharBlock &name);
 
   int metaLevel_{0};
+  const parser::OmpMetadirectiveDirective *metaDirective_{nullptr};
 };
 
 bool OmpVisitor::NeedsScope(const parser::OpenMPBlockConstruct &x) {
@@ -1930,7 +1939,8 @@ bool OmpVisitor::Pre(const parser::OmpDirectiveSpecification &x) {
     if (maybeArgs && maybeClauses) {
       const parser::OmpArgument &first{maybeArgs->v.front()};
       if (auto *spec{std::get_if<parser::OmpReductionSpecifier>(&first.u)}) {
-        ProcessReductionSpecifier(*spec, maybeClauses, x);
+        CHECK(metaDirective_);
+        ProcessReductionSpecifier(*spec, maybeClauses, *metaDirective_);
       }
     }
     break;

flang/test/Semantics/OpenMP/declare-reduction-modfile.f90

@@ -1,4 +1,4 @@
-! RUN: %python %S/../test_modfile.py %s %flang_fc1 -fopenmp
+! RUN: %python %S/../test_modfile.py %s %flang_fc1 -fopenmp -fopenmp-version=52
 ! Check correct modfile generation for OpenMP DECLARE REDUCTION construct.
 
 !Expect: drm.mod
@@ -8,6 +8,7 @@
 !endtype
 !!$OMP DECLARE REDUCTION (*:t1:omp_out = omp_out*omp_in) INITIALIZER(omp_priv=t&
 !!$OMP&1(1))
+!!$OMP METADIRECTIVE OTHERWISE(DECLARE REDUCTION(+:INTEGER))
 !!$OMP DECLARE REDUCTION (.fluffy.:t1:omp_out = omp_out.fluffy.omp_in) INITIALI&
 !!$OMP&ZER(omp_priv=t1(0))
 !!$OMP DECLARE REDUCTION (.mul.:t1:omp_out = omp_out.mul.omp_in) INITIALIZER(om&
@@ -50,6 +51,7 @@ module drm
 !$omp declare reduction(*:t1:omp_out=omp_out*omp_in) initializer(omp_priv=t1(1))
 !$omp declare reduction(.mul.:t1:omp_out=omp_out.mul.omp_in) initializer(omp_priv=t1(1))
 !$omp declare reduction(.fluffy.:t1:omp_out=omp_out.fluffy.omp_in) initializer(omp_priv=t1(0))
+!$omp metadirective otherwise(declare reduction(+: integer))
 contains
   type(t1) function mul(v1, v2)
     type(t1), intent (in):: v1, v2