Revert "[OpenMP] Do not propagate match extensions to nested contexts"

Two tests failed for some reason, need to investigate:
  https://lab.llvm.org/buildbot/#/builders/109/builds/10399

This reverts commit ad9e98b8ef.

clang/include/clang/Basic/AttrDocs.td

@@ -4014,8 +4014,7 @@ The match extensions change when the *entire* context selector is considered a
 match for an OpenMP context. The default is ``all``, with ``none`` no trait in the
 selector is allowed to be in the OpenMP context, with ``any`` a single trait in
 both the selector and OpenMP context is sufficient. Only a single match
-extension trait is allowed per context selector. Note that match extensions are
-not propagated to nested selectors like the standard defines it for other traits.
+extension trait is allowed per context selector.
 The disable extensions remove default effects of the ``begin declare variant``
 applied to a definition. If ``disable_implicit_base`` is given, we will not
 introduce an implicit base function for a variant if no base function was

clang/lib/Parse/ParseOpenMP.cpp

@@ -21,7 +21,6 @@
 #include "clang/Parse/RAIIObjectsForParser.h"
 #include "clang/Sema/Scope.h"
 #include "llvm/ADT/PointerIntPair.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/UniqueVector.h"
 #include "llvm/Frontend/OpenMP/OMPContext.h"
@@ -1464,29 +1463,7 @@ bool Parser::parseOMPDeclareVariantMatchClause(SourceLocation Loc,
   // TODO: Keep some source location in the TI to provide better diagnostics.
   // TODO: Perform some kind of equivalence check on the condition and score
   //       expressions.
-  auto StripImplementation = [](const OMPTraitSet &TSet) -> OMPTraitSet {
-    if (TSet.Kind != llvm::omp::TraitSet::implementation)
-      return TSet;
-    OMPTraitSet Set = TSet;
-    for (OMPTraitSelector &Selector : Set.Selectors) {
-      if (Selector.Kind != llvm::omp::TraitSelector::implementation_extension)
-        continue;
-      // Do not propagate match extensions to nested contexts.
-      llvm::erase_if(Selector.Properties, [](const OMPTraitProperty &Property) {
-        return (
-            Property.Kind ==
-                llvm::omp::TraitProperty::implementation_extension_match_any ||
-            Property.Kind ==
-                llvm::omp::TraitProperty::implementation_extension_match_all ||
-            Property.Kind ==
-                llvm::omp::TraitProperty::implementation_extension_match_none);
-      });
-      return Set;
-    }
-    return Set;
-  };
-  for (const OMPTraitSet &PSet : ParentTI->Sets) {
-    const OMPTraitSet ParentSet = StripImplementation(PSet);
+  for (const OMPTraitSet &ParentSet : ParentTI->Sets) {
     bool MergedSet = false;
     for (OMPTraitSet &Set : TI.Sets) {
       if (Set.Kind != ParentSet.Kind)

clang/test/OpenMP/begin_declare_variant_nested_propagation.c

@@ -1,14 +0,0 @@
-// RUN: %clang_cc1 -triple=x86_64-pc-win32 -verify -fopenmp -x c -std=c99 -fms-extensions -Wno-pragma-pack %s
-// expected-no-diagnostics
-
-#pragma omp begin declare variant match(user={condition(1)}, device={kind(cpu)}, implementation={extension(match_any)})
-#pragma omp begin declare variant match(device = {kind(cpu, fpga)})
- this is never reached
-#pragma omp end declare variant
-#pragma omp end declare variant
-
-#pragma omp begin declare variant match(user={condition(1)}, device={kind(cpu)}, implementation={extension(match_any)})
-#pragma omp begin declare variant match(device = {kind(cpu, fpga)}, implementation={vendor(llvm)})
- this is never reached
-#pragma omp end declare variant
-#pragma omp end declare variant

llvm/lib/Frontend/OpenMP/OMPContext.cpp

@@ -168,13 +168,8 @@ static int isVariantApplicableInContextHelper(
     // For kind "any" a single match is enough but we ignore non-matched
     // properties.
     if (MK == MK_ANY) {
-      if (WasFound) {
-        LLVM_DEBUG(
-            dbgs() << "[" << DEBUG_TYPE << "] Property "
-                   << getOpenMPContextTraitPropertyName(Property, "")
-                   << " was in the OpenMP context and match kind is any.\n";);
+      if (WasFound)
         return true;
-      }
       return None;
     }