TableGen: Allow use of #NAME# outside of 'def' names.

Previously, def NAME values were only populated, and references to NAME
resolved, when NAME was referenced in the 'def' entry of the multiclass
sub-entry. e.g.,
multiclass foo<...> {
  def prefix_#NAME : ...
}

It's useful, however, to be able to reference NAME even when the default
def name is used. For example, when a multiclass has 'def : Pat<...>'
or 'def : InstAlias<...>' entries which refer to earlier instruction
definitions in the same multiclass. e.g.,
multiclass myMulti<RegisterClass rc> {
  def _r : myI<(outs rc:$d), (ins rc:$r), "r $d, $r", []>;

  def : InstAlias<\"wilma $r\", (!cast<Instruction>(NAME#\"_r\") rc:$r, rc:$r)>;
}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161198 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 21 insertions, 11 deletions

diff --git a/lib/TableGen/TGParser.cpp b/lib/TableGen/TGParser.cpp
index 9424677800..b9c7ff694d 100644
--- a/lib/TableGen/TGParser.cpp
+++ b/lib/TableGen/TGParser.cpp
@@ -2284,23 +2284,33 @@ InstantiateMulticlassDef(MultiClass &MC,
   Ref.Rec = DefProto;
   AddSubClass(CurRec, Ref);
 
-  if (DefNameString == 0) {
-    // We must resolve references to NAME.
-    if (SetValue(CurRec, Ref.RefLoc, "NAME", std::vector<unsigned>(),
-                 DefmPrefix)) {
-      Error(DefmPrefixLoc, "Could not resolve "
-            + CurRec->getNameInitAsString() + ":NAME to '"
-            + DefmPrefix->getAsUnquotedString() + "'");
-      return 0;
-    }
+  // Set the value for NAME. We don't resolve references to it 'til later,
+  // though, so that uses in nested multiclass names don't get
+  // confused.
+  if (SetValue(CurRec, Ref.RefLoc, "NAME", std::vector<unsigned>(),
+               DefmPrefix)) {
+    Error(DefmPrefixLoc, "Could not resolve "
+          + CurRec->getNameInitAsString() + ":NAME to '"
+          + DefmPrefix->getAsUnquotedString() + "'");
+    return 0;
+  }
 
+  // If the DefNameString didn't resolve, we probably have a reference to
+  // NAME and need to replace it. We need to do at least this much greedily,
+  // otherwise nested multiclasses will end up with incorrect NAME expansions.
+  if (DefNameString == 0) {
     RecordVal *DefNameRV = CurRec->getValue("NAME");
     CurRec->resolveReferencesTo(DefNameRV);
   }
 
   if (!CurMultiClass) {
-    // We do this after resolving NAME because before resolution, many
-    // multiclass defs will have the same name expression.  If we are
+    // Now that we're at the top level, resolve all NAME references
+    // in the resultant defs that weren't in the def names themselves.
+    RecordVal *DefNameRV = CurRec->getValue("NAME");
+    CurRec->resolveReferencesTo(DefNameRV);
+
+    // Now that NAME references are resolved and we're at the top level of
+    // any multiclass expansions, add the record to the RecordKeeper. If we are
     // currently in a multiclass, it means this defm appears inside a
     // multiclass and its name won't be fully resolvable until we see
     // the top-level defm.  Therefore, we don't add this to the