[OPENMP 4.0] Initial support for 'omp declare reduction' construct.

Add parsing, sema analysis and serialization/deserialization for 'declare reduction' construct.
User-defined reductions are defined as

#pragma omp declare reduction( reduction-identifier : typename-list : combiner ) [initializer ( initializer-expr )]
These custom reductions may be used in 'reduction' clauses of OpenMP constructs. The combiner specifies how partial results can be combined into a single value. The
combiner can use the special variable identifiers omp_in and omp_out that are of the type of the variables being reduced with this reduction-identifier. Each of them will
denote one of the values to be combined before executing the combiner. It is assumed that the special omp_out identifier will refer to the storage that holds the resulting
combined value after executing the combiner.
As the initializer-expr value of a user-defined reduction is not known a priori the initializer-clause can be used to specify one. Then the contents of the initializer-clause
will be used as the initializer for private copies of reduction list items where the omp_priv identifier will refer to the storage to be initialized. The special identifier
omp_orig can also appear in the initializer-clause and it will refer to the storage of the original variable to be reduced.
Differential Revision: http://reviews.llvm.org/D11182

llvm-svn: 262582

1 files changed, 3 insertions, 5 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index ab6f3cc..8e6f1ab 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -3644,13 +3644,11 @@ void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
     }
 
     if (Tok.is(tok::annot_pragma_openmp)) {
-      // Result can be ignored, because it must be always empty.
-      auto Res = ParseOpenMPDeclarativeDirective();
-      assert(!Res);
-      // Silence possible warnings.
-      (void)Res;
+      // There may be declared reduction operator inside structure/union.
+      (void)ParseOpenMPDeclarativeDirective(AS_public);
       continue;
     }
+
     if (!Tok.is(tok::at)) {
       auto CFieldCallback = [&](ParsingFieldDeclarator &FD) {
         // Install the declarator into the current TagDecl.