[OpenMP] Fix handling of clause on wrong directive, by Joel. E. Denny

Summary:
First, this patch fixes an assert failure when, for example, "omp for"
has num_teams.

Second, this patch prevents duplicate diagnostics when, for example,
"omp for" has uniform.

This patch makes the general assumption (even where it doesn't
necessarily fix an existing bug) that it is worthless to perform sema
for a clause that appears on a directive on which OpenMP does not
permit that clause.  However, due to this assumption, this patch
suppresses some diagnostics that were expected in the test suite.  I
assert that those diagnostics were likely just distracting to the
user.

Reviewers: ABataev

Reviewed By: ABataev

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D41841

llvm-svn: 322107

1 files changed, 30 insertions, 13 deletions

diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
index 628c1f134ac..f3edf7ca51f 100644
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -1205,11 +1205,13 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
                                      OpenMPClauseKind CKind, bool FirstClause) {
   OMPClause *Clause = nullptr;
   bool ErrorFound = false;
+  bool WrongDirective = false;
   // Check if clause is allowed for the given directive.
   if (CKind != OMPC_unknown && !isAllowedClauseForDirective(DKind, CKind)) {
     Diag(Tok, diag::err_omp_unexpected_clause) << getOpenMPClauseName(CKind)
                                                << getOpenMPDirectiveName(DKind);
     ErrorFound = true;
+    WrongDirective = true;
   }
 
   switch (CKind) {
@@ -1253,9 +1255,9 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
     }
 
     if (CKind == OMPC_ordered && PP.LookAhead(/*N=*/0).isNot(tok::l_paren))
-      Clause = ParseOpenMPClause(CKind);
+      Clause = ParseOpenMPClause(CKind, WrongDirective);
     else
-      Clause = ParseOpenMPSingleExprClause(CKind);
+      Clause = ParseOpenMPSingleExprClause(CKind, WrongDirective);
     break;
   case OMPC_default:
   case OMPC_proc_bind:
@@ -1270,7 +1272,7 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
       ErrorFound = true;
     }
 
-    Clause = ParseOpenMPSimpleClause(CKind);
+    Clause = ParseOpenMPSimpleClause(CKind, WrongDirective);
     break;
   case OMPC_schedule:
   case OMPC_dist_schedule:
@@ -1287,7 +1289,7 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
     LLVM_FALLTHROUGH;
 
   case OMPC_if:
-    Clause = ParseOpenMPSingleExprWithArgClause(CKind);
+    Clause = ParseOpenMPSingleExprWithArgClause(CKind, WrongDirective);
     break;
   case OMPC_nowait:
   case OMPC_untied:
@@ -1310,7 +1312,7 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
       ErrorFound = true;
     }
 
-    Clause = ParseOpenMPClause(CKind);
+    Clause = ParseOpenMPClause(CKind, WrongDirective);
     break;
   case OMPC_private:
   case OMPC_firstprivate:
@@ -1330,7 +1332,7 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
   case OMPC_from:
   case OMPC_use_device_ptr:
   case OMPC_is_device_ptr:
-    Clause = ParseOpenMPVarListClause(DKind, CKind);
+    Clause = ParseOpenMPVarListClause(DKind, CKind, WrongDirective);
     break;
   case OMPC_unknown:
     Diag(Tok, diag::warn_omp_extra_tokens_at_eol)
@@ -1339,8 +1341,9 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
     break;
   case OMPC_threadprivate:
   case OMPC_uniform:
-    Diag(Tok, diag::err_omp_unexpected_clause) << getOpenMPClauseName(CKind)
-                                               << getOpenMPDirectiveName(DKind);
+    if (!WrongDirective)
+      Diag(Tok, diag::err_omp_unexpected_clause)
+          << getOpenMPClauseName(CKind) << getOpenMPDirectiveName(DKind);
     SkipUntil(tok::comma, tok::annot_pragma_openmp_end, StopBeforeMatch);
     break;
   }
@@ -1400,7 +1403,8 @@ ExprResult Parser::ParseOpenMPParensExpr(StringRef ClauseName,
 ///    hint-clause:
 ///      'hint' '(' expression ')'
 ///
-OMPClause *Parser::ParseOpenMPSingleExprClause(OpenMPClauseKind Kind) {
+OMPClause *Parser::ParseOpenMPSingleExprClause(OpenMPClauseKind Kind,
+                                               bool ParseOnly) {
   SourceLocation Loc = ConsumeToken();
   SourceLocation LLoc = Tok.getLocation();
   SourceLocation RLoc;
@@ -1410,6 +1414,8 @@ OMPClause *Parser::ParseOpenMPSingleExprClause(OpenMPClauseKind Kind) {
   if (Val.isInvalid())
     return nullptr;
 
+  if (ParseOnly)
+    return nullptr;
   return Actions.ActOnOpenMPSingleExprClause(Kind, Val.get(), Loc, LLoc, RLoc);
 }
 
@@ -1421,7 +1427,8 @@ OMPClause *Parser::ParseOpenMPSingleExprClause(OpenMPClauseKind Kind) {
 ///    proc_bind-clause:
 ///         'proc_bind' '(' 'master' | 'close' | 'spread' ')
 ///
-OMPClause *Parser::ParseOpenMPSimpleClause(OpenMPClauseKind Kind) {
+OMPClause *Parser::ParseOpenMPSimpleClause(OpenMPClauseKind Kind,
+                                           bool ParseOnly) {
   SourceLocation Loc = Tok.getLocation();
   SourceLocation LOpen = ConsumeToken();
   // Parse '('.
@@ -1440,6 +1447,8 @@ OMPClause *Parser::ParseOpenMPSimpleClause(OpenMPClauseKind Kind) {
   // Parse ')'.
   T.consumeClose();
 
+  if (ParseOnly)
+    return nullptr;
   return Actions.ActOnOpenMPSimpleClause(Kind, Type, TypeLoc, LOpen, Loc,
                                          Tok.getLocation());
 }
@@ -1470,10 +1479,12 @@ OMPClause *Parser::ParseOpenMPSimpleClause(OpenMPClauseKind Kind) {
 ///    nogroup-clause:
 ///         'nogroup'
 ///
-OMPClause *Parser::ParseOpenMPClause(OpenMPClauseKind Kind) {
+OMPClause *Parser::ParseOpenMPClause(OpenMPClauseKind Kind, bool ParseOnly) {
   SourceLocation Loc = Tok.getLocation();
   ConsumeAnyToken();
 
+  if (ParseOnly)
+    return nullptr;
   return Actions.ActOnOpenMPClause(Kind, Loc, Tok.getLocation());
 }
 
@@ -1491,7 +1502,8 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPClauseKind Kind) {
 ///    defaultmap:
 ///      'defaultmap' '(' modifier ':' kind ')'
 ///
-OMPClause *Parser::ParseOpenMPSingleExprWithArgClause(OpenMPClauseKind Kind) {
+OMPClause *Parser::ParseOpenMPSingleExprWithArgClause(OpenMPClauseKind Kind,
+                                                      bool ParseOnly) {
   SourceLocation Loc = ConsumeToken();
   SourceLocation DelimLoc;
   // Parse '('.
@@ -1613,6 +1625,8 @@ OMPClause *Parser::ParseOpenMPSingleExprWithArgClause(OpenMPClauseKind Kind) {
   if (NeedAnExpression && Val.isInvalid())
     return nullptr;
 
+  if (ParseOnly)
+    return nullptr;
   return Actions.ActOnOpenMPSingleExprWithArgClause(
       Kind, Arg, Val.get(), Loc, T.getOpenLocation(), KLoc, DelimLoc,
       T.getCloseLocation());
@@ -1940,7 +1954,8 @@ bool Parser::ParseOpenMPVarList(OpenMPDirectiveKind DKind,
 ///  modifier(list)
 /// where modifier is 'val' (C) or 'ref', 'val' or 'uval'(C++).
 OMPClause *Parser::ParseOpenMPVarListClause(OpenMPDirectiveKind DKind,
-                                            OpenMPClauseKind Kind) {
+                                            OpenMPClauseKind Kind,
+                                            bool ParseOnly) {
   SourceLocation Loc = Tok.getLocation();
   SourceLocation LOpen = ConsumeToken();
   SmallVector<Expr *, 4> Vars;
@@ -1949,6 +1964,8 @@ OMPClause *Parser::ParseOpenMPVarListClause(OpenMPDirectiveKind DKind,
   if (ParseOpenMPVarList(DKind, Kind, Vars, Data))
     return nullptr;
 
+  if (ParseOnly)
+    return nullptr;
   return Actions.ActOnOpenMPVarListClause(
       Kind, Vars, Data.TailExpr, Loc, LOpen, Data.ColonLoc, Tok.getLocation(),
       Data.ReductionIdScopeSpec, Data.ReductionId, Data.DepKind, Data.LinKind,