[TableGen] Fix source location for anonymous records

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

Current code tags the location of the class on the record that is
created when a class is anonymously instantiated via
`VarDefInit::instantiate`. Instead, pass in the `SMLoc` for the
place where the anonymous instantiation happens and use as the location
when the record is instantiated. If there are multiple instantiations
with the same paramaters, the location for the record created will be
one of these instantiation locations as opposed to the class location.

Added unit test using detailed record printer. It only prints the base
name of the file when printing locations, so added support for
`%basename_s` in LLVM's LIT testing framework to get the base name of
the source file.

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;
+}