Fix evil TableGen bug in template parameters with defaults.

If a TableGen class has an initializer expression containing an X.Y subexpression,
AND X depends on template parameters,
AND those template parameters have defaults,
AND some parameters with defaults are beyond position 1,
THEN parts of the initializer expression are evaluated prematurely with the default values when the first explicit template parameter is substituted, before the remaining explicit template parameters have been substituted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99492 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 8 deletions

diff --git a/utils/TableGen/Record.cpp b/utils/TableGen/Record.cpp
index b9facb4c2a..0e3593b6a1 100644
--- a/utils/TableGen/Record.cpp
+++ b/utils/TableGen/Record.cpp
@@ -1108,12 +1108,15 @@ RecTy *VarInit::getFieldType(const std::string &FieldName) const {
   return 0;
 }
 
-Init *VarInit::getFieldInit(Record &R, const std::string &FieldName) const {
+Init *VarInit::getFieldInit(Record &R, const RecordVal *RV,
+                            const std::string &FieldName) const {
   if (dynamic_cast<RecordRecTy*>(getType()))
-    if (const RecordVal *RV = R.getValue(VarName)) {
-      Init *TheInit = RV->getValue();
+    if (const RecordVal *Val = R.getValue(VarName)) {
+      if (RV != Val && (RV || dynamic_cast<UnsetInit*>(Val->getValue())))
+        return 0;
+      Init *TheInit = Val->getValue();
       assert(TheInit != this && "Infinite loop detected!");
-      if (Init *I = TheInit->getFieldInit(R, FieldName))
+      if (Init *I = TheInit->getFieldInit(R, RV, FieldName))
         return I;
       else
         return 0;
@@ -1174,7 +1177,8 @@ RecTy *DefInit::getFieldType(const std::string &FieldName) const {
   return 0;
 }
 
-Init *DefInit::getFieldInit(Record &R, const std::string &FieldName) const {
+Init *DefInit::getFieldInit(Record &R, const RecordVal *RV,
+                            const std::string &FieldName) const {
   return Def->getValue(FieldName)->getValue();
 }
 
@@ -1185,7 +1189,7 @@ std::string DefInit::getAsString() const {
 
 Init *FieldInit::resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) {
-  if (Init *BitsVal = Rec->getFieldInit(R, FieldName))
+  if (Init *BitsVal = Rec->getFieldInit(R, RV, FieldName))
     if (BitsInit *BI = dynamic_cast<BitsInit*>(BitsVal)) {
       assert(Bit < BI->getNumBits() && "Bit reference out of range!");
       Init *B = BI->getBit(Bit);
@@ -1198,7 +1202,7 @@ Init *FieldInit::resolveBitReference(Record &R, const RecordVal *RV,
 
 Init *FieldInit::resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) {
-  if (Init *ListVal = Rec->getFieldInit(R, FieldName))
+  if (Init *ListVal = Rec->getFieldInit(R, RV, FieldName))
     if (ListInit *LI = dynamic_cast<ListInit*>(ListVal)) {
       if (Elt >= LI->getSize()) return 0;
       Init *E = LI->getElement(Elt);
@@ -1215,7 +1219,7 @@ Init *FieldInit::resolveListElementReference(Record &R, const RecordVal *RV,
 Init *FieldInit::resolveReferences(Record &R, const RecordVal *RV) {
   Init *NewRec = RV ? Rec->resolveReferences(R, RV) : Rec;
 
-  Init *BitsVal = NewRec->getFieldInit(R, FieldName);
+  Init *BitsVal = NewRec->getFieldInit(R, RV, FieldName);
   if (BitsVal) {
     Init *BVR = BitsVal->resolveReferences(R, RV);
     return BVR->isComplete() ? BVR : this;