[PATCH] D83061: [OpenMP] Implement TR8 `present` map type modifier in Clang (1/2)

[Alexey Bataev via Phabricator via cfe-commits]

ABataev added inline comments.


================
Comment at: clang/lib/Parse/ParseOpenMP.cpp:3067-3068
+  unsigned Type = getOpenMPSimpleClauseType(OMPC_map, PP.getSpelling(Tok));
+  if (Type < OMPC_MAP_MODIFIER_unknown)
+    return OMPC_MAP_MODIFIER_unknown;
+  return static_cast<OpenMPMapModifierKind>(Type);
----------------
jdenny wrote:
> ABataev wrote:
> > Why do we need this?
> When called with `OMPC_map`, `getOpenMPSimpleClauseType` can return either an `OpenMPMapModifierKind` or `OpenMPMapClauseKind` depending on `Tok`.  Thus, without this change, both `isMapModifier` and `isMapType` can return either of those despite the difference in their names and documentation.
> 
> I found that, when `Parser::parseMapTypeModifiers` ignores `present` as if it's not a modifier because OpenMP < 5.1, then `isMapType` later returns `OMPC_MAP_MODIFIER_present` and causes the following assert to fail in `Sema::ActOnOpenMPVarListClause`:
> 
> ```
> assert(0 <= ExtraModifier && ExtraModifier <= OMPC_MAP_unknown &&
>            "Unexpected map modifier.");
> ```
> 
> To me, the most obvious solution is to fix `isMapType` and `isMapModifier`.  Fortunately, looking in `OpenMPKinds.h`, the enumerator values in `OpenMPMapModifierKind` and `OpenMPMapClauseKind` are disjoint so we can tell which we have.
Can we have something like:
```
if (LangOpts.OpenMP <= 50 && Type == OMPC_MAP_MODIFIER_present)
  return OMPC_MAP_MODIFIER_unknown;
```
or extend `getOpenMPSimpleClauseType` function with the version parameter and check there is modifier is allowed and return `unknown` if it is not compatible with provided version?


================
Comment at: clang/lib/Parse/ParseOpenMP.cpp:3103
 /// map([ [map-type-modifier[,] [map-type-modifier[,] ...] map-type : ] list)
 /// where, map-type-modifier ::= always | close | mapper(mapper-identifier)
 bool Parser::parseMapTypeModifiers(OpenMPVarListDataTy &Data) {
----------------
Update a comment here


================
Comment at: clang/test/OpenMP/target_data_codegen.cpp:258-260
+// CK1A: [[MTYPE00:@.+]] = {{.+}}constant [1 x i64] [i64 [[#0x1021]]]
+
+// CK1A: [[MTYPE01:@.+]] = {{.+}}constant [1 x i64] [i64 [[#0x1425]]]
----------------
Add a comment with interpretaion of the map flags, like `OMP_TO = 0x1 | OMP_FROM=0x2 | OMP_PRESENT = 0x1000 = 0x1003`


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83061/new/

https://reviews.llvm.org/D83061