[OpenMP][clang] 6.0: parsing/sema for num_threads 'strict' modifier (#145490)

Implement parsing and semantic analysis support for the optional
'strict' modifier of the num_threads clause. This modifier has been
introduced in OpenMP 6.0, section 12.1.2.

Note: this is basically 1:1 https://reviews.llvm.org/D138328.

1 files changed, 31 insertions, 2 deletions

diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
index 78d3503..f694ae1 100644
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -3196,7 +3196,8 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
     if ((CKind == OMPC_ordered || CKind == OMPC_partial) &&
         PP.LookAhead(/*N=*/0).isNot(tok::l_paren))
       Clause = ParseOpenMPClause(CKind, WrongDirective);
-    else if (CKind == OMPC_grainsize || CKind == OMPC_num_tasks)
+    else if (CKind == OMPC_grainsize || CKind == OMPC_num_tasks ||
+             CKind == OMPC_num_threads)
       Clause = ParseOpenMPSingleExprWithArgClause(DKind, CKind, WrongDirective);
     else
       Clause = ParseOpenMPSingleExprClause(CKind, WrongDirective);
@@ -3981,6 +3982,33 @@ OMPClause *Parser::ParseOpenMPSingleExprWithArgClause(OpenMPDirectiveKind DKind,
       Arg.push_back(OMPC_NUMTASKS_unknown);
       KLoc.emplace_back();
     }
+  } else if (Kind == OMPC_num_threads) {
+    // Parse optional <num_threads modifier> ':'
+    OpenMPNumThreadsClauseModifier Modifier =
+        static_cast<OpenMPNumThreadsClauseModifier>(getOpenMPSimpleClauseType(
+            Kind, Tok.isAnnotation() ? "" : PP.getSpelling(Tok),
+            getLangOpts()));
+    if (getLangOpts().OpenMP >= 60) {
+      if (NextToken().is(tok::colon)) {
+        Arg.push_back(Modifier);
+        KLoc.push_back(Tok.getLocation());
+        // Parse modifier
+        ConsumeAnyToken();
+        // Parse ':'
+        ConsumeAnyToken();
+      } else {
+        if (Modifier == OMPC_NUMTHREADS_strict) {
+          Diag(Tok, diag::err_modifier_expected_colon) << "strict";
+          // Parse modifier
+          ConsumeAnyToken();
+        }
+        Arg.push_back(OMPC_NUMTHREADS_unknown);
+        KLoc.emplace_back();
+      }
+    } else {
+      Arg.push_back(OMPC_NUMTHREADS_unknown);
+      KLoc.emplace_back();
+    }
   } else {
     assert(Kind == OMPC_if);
     KLoc.push_back(Tok.getLocation());
@@ -4004,7 +4032,8 @@ OMPClause *Parser::ParseOpenMPSingleExprWithArgClause(OpenMPDirectiveKind DKind,
   bool NeedAnExpression = (Kind == OMPC_schedule && DelimLoc.isValid()) ||
                           (Kind == OMPC_dist_schedule && DelimLoc.isValid()) ||
                           Kind == OMPC_if || Kind == OMPC_device ||
-                          Kind == OMPC_grainsize || Kind == OMPC_num_tasks;
+                          Kind == OMPC_grainsize || Kind == OMPC_num_tasks ||
+                          Kind == OMPC_num_threads;
   if (NeedAnExpression) {
     SourceLocation ELoc = Tok.getLocation();
     ExprResult LHS(ParseCastExpression(CastParseKind::AnyCastExpr, false,