[TableGen] Fix source location for anonymous records (llvm#110935)

Fix source location for anonymous records to be the one of the locations
where that record is instantiated as opposed to the location of the
class that was anonymously instantiated.

Currently, when a record is anonymously instantiated (via
`VarDefInit::instantiate`), we use the location of the class for the
record, which is not correct. Instead, pass in the `SMLoc` for the
location where the anonymous instantiation happens and use that location
when the record is instantiated. If there are multiple anonymous
instantiations with the same parameters, the location for the (single)
record created will be one of these instantiation locations as opposed
to the class location.

Author: jurahul

llvm/include/llvm/TableGen/Record.h

@@ -1347,11 +1347,12 @@ class DefInit : public TypedInit {
 class VarDefInit final : public TypedInit,
                          public FoldingSetNode,
                          public TrailingObjects<VarDefInit, ArgumentInit *> {
+  SMLoc Loc;
   Record *Class;
   DefInit *Def = nullptr; // after instantiation
   unsigned NumArgs;
 
-  explicit VarDefInit(Record *Class, unsigned N);
+  explicit VarDefInit(SMLoc Loc, Record *Class, unsigned N);
 
   DefInit *instantiate();
 
@@ -1365,7 +1366,8 @@ class VarDefInit final : public TypedInit,
   static bool classof(const Init *I) {
     return I->getKind() == IK_VarDefInit;
   }
-  static VarDefInit *get(Record *Class, ArrayRef<ArgumentInit *> Args);
+  static VarDefInit *get(SMLoc Loc, Record *Class,
+                         ArrayRef<ArgumentInit *> Args);
 
   void Profile(FoldingSetNodeID &ID) const;
 

llvm/lib/TableGen/Record.cpp

@@ -2292,11 +2292,12 @@ static void ProfileVarDefInit(FoldingSetNodeID &ID, Record *Class,
     ID.AddPointer(I);
 }
 
-VarDefInit::VarDefInit(Record *Class, unsigned N)
-    : TypedInit(IK_VarDefInit, RecordRecTy::get(Class)), Class(Class),
+VarDefInit::VarDefInit(SMLoc Loc, Record *Class, unsigned N)
+    : TypedInit(IK_VarDefInit, RecordRecTy::get(Class)), Loc(Loc), Class(Class),
       NumArgs(N) {}
 
-VarDefInit *VarDefInit::get(Record *Class, ArrayRef<ArgumentInit *> Args) {
+VarDefInit *VarDefInit::get(SMLoc Loc, Record *Class,
+                            ArrayRef<ArgumentInit *> Args) {
   FoldingSetNodeID ID;
   ProfileVarDefInit(ID, Class, Args);
 
@@ -2307,7 +2308,7 @@ VarDefInit *VarDefInit::get(Record *Class, ArrayRef<ArgumentInit *> Args) {
 
   void *Mem = RK.Allocator.Allocate(
       totalSizeToAlloc<ArgumentInit *>(Args.size()), alignof(VarDefInit));
-  VarDefInit *I = new (Mem) VarDefInit(Class, Args.size());
+  VarDefInit *I = new (Mem) VarDefInit(Loc, Class, Args.size());
   std::uninitialized_copy(Args.begin(), Args.end(),
                           I->getTrailingObjects<ArgumentInit *>());
   RK.TheVarDefInitPool.InsertNode(I, IP);
@@ -2323,9 +2324,8 @@ DefInit *VarDefInit::instantiate() {
     return Def;
 
   RecordKeeper &Records = Class->getRecords();
-  auto NewRecOwner =
-      std::make_unique<Record>(Records.getNewAnonymousName(), Class->getLoc(),
-                               Records, Record::RK_AnonymousDef);
+  auto NewRecOwner = std::make_unique<Record>(
+      Records.getNewAnonymousName(), Loc, Records, Record::RK_AnonymousDef);
   Record *NewRec = NewRecOwner.get();
 
   // Copy values from class to instance
@@ -2389,7 +2389,7 @@ Init *VarDefInit::resolveReferences(Resolver &R) const {
   }
 
   if (Changed) {
-    auto New = VarDefInit::get(Class, NewArgs);
+    auto *New = VarDefInit::get(Loc, Class, NewArgs);
     if (!UR.foundUnresolved())
       return New->instantiate();
     return New;

llvm/lib/TableGen/TGParser.cpp

@@ -2719,7 +2719,7 @@ Init *TGParser::ParseSimpleValue(Record *CurRec, const RecTy *ItemType,
 
     if (TrackReferenceLocs)
       Class->appendReferenceLoc(NameLoc);
-    return VarDefInit::get(Class, Args)->Fold();
+    return VarDefInit::get(NameLoc.Start, Class, Args)->Fold();
   }
   case tgtok::l_brace: {           // Value ::= '{' ValueList '}'
     SMLoc BraceLoc = Lex.getLoc();

llvm/test/TableGen/anonymous-location.td

@@ -0,0 +1,16 @@
+// RUN: llvm-tblgen --print-detailed-records %s | FileCheck %s -DFILE=anonymous-location.td
+
+class A<int a> {
+  int Num = a;
+}
+
+// Verify that the location of the anonymous record instantiated
+// for A<10> and A<11> is correct. It should show the line where the
+// anonymous record was instantiated and not the line where the class
+// was defined.
+def y {
+  // CHECK: anonymous_0 |[[FILE]]:[[@LINE+1]]|
+  int x = A<10>.Num;
+  // CHECK: anonymous_1 |[[FILE]]:[[@LINE+1]]|
+  int y = A<11>.Num;
+}