[Mlir-commits] [mlir] [mlir] Add support for DIGlobalVariable and DIGlobalVariableExpression (PR #73367)

[Justin Wilson]

================
@@ -109,3 +119,251 @@ bool MemoryEffectsAttr::isReadWrite() {
     return false;
   return true;
 }
+
+//===----------------------------------------------------------------------===//
+// DIExpression
+//===----------------------------------------------------------------------===//
+
+DIExpressionAttr DIExpressionAttr::get(MLIRContext *context) {
+  return get(context, ArrayRef<uint64_t>({}));
+}
+
+#define _FORMAT_DW_OP(x) #x
+#define FORMAT_DW_OP(NAME, VENDOR) _FORMAT_DW_OP(DW_OP_##VENDOR##_##NAME)
+
+size_t queryNumOpParams(llvm::dwarf::LocationAtom op) {
+  switch (op) {
+  case llvm::dwarf::DW_OP_addr:
+  case llvm::dwarf::DW_OP_const1u:
+  case llvm::dwarf::DW_OP_const1s:
+  case llvm::dwarf::DW_OP_const2u:
+  case llvm::dwarf::DW_OP_const2s:
+  case llvm::dwarf::DW_OP_const4u:
+  case llvm::dwarf::DW_OP_const4s:
+  case llvm::dwarf::DW_OP_const8u:
+  case llvm::dwarf::DW_OP_const8s:
+  case llvm::dwarf::DW_OP_constu:
+  case llvm::dwarf::DW_OP_consts:
+  case llvm::dwarf::DW_OP_pick:
+  case llvm::dwarf::DW_OP_plus_uconst:
+  case llvm::dwarf::DW_OP_bra:
+  case llvm::dwarf::DW_OP_skip:
+  case llvm::dwarf::DW_OP_breg0:
+  case llvm::dwarf::DW_OP_breg1:
+  case llvm::dwarf::DW_OP_breg2:
+  case llvm::dwarf::DW_OP_breg3:
+  case llvm::dwarf::DW_OP_breg4:
+  case llvm::dwarf::DW_OP_breg5:
+  case llvm::dwarf::DW_OP_breg6:
+  case llvm::dwarf::DW_OP_breg7:
+  case llvm::dwarf::DW_OP_breg8:
+  case llvm::dwarf::DW_OP_breg9:
+  case llvm::dwarf::DW_OP_breg10:
+  case llvm::dwarf::DW_OP_breg11:
+  case llvm::dwarf::DW_OP_breg12:
+  case llvm::dwarf::DW_OP_breg13:
+  case llvm::dwarf::DW_OP_breg14:
+  case llvm::dwarf::DW_OP_breg15:
+  case llvm::dwarf::DW_OP_breg16:
+  case llvm::dwarf::DW_OP_breg17:
+  case llvm::dwarf::DW_OP_breg18:
+  case llvm::dwarf::DW_OP_breg19:
+  case llvm::dwarf::DW_OP_breg20:
+  case llvm::dwarf::DW_OP_breg21:
+  case llvm::dwarf::DW_OP_breg22:
+  case llvm::dwarf::DW_OP_breg23:
+  case llvm::dwarf::DW_OP_breg24:
+  case llvm::dwarf::DW_OP_breg25:
+  case llvm::dwarf::DW_OP_breg26:
+  case llvm::dwarf::DW_OP_breg27:
+  case llvm::dwarf::DW_OP_breg28:
+  case llvm::dwarf::DW_OP_breg29:
+  case llvm::dwarf::DW_OP_breg30:
+  case llvm::dwarf::DW_OP_breg31:
+  case llvm::dwarf::DW_OP_regx:
+  case llvm::dwarf::DW_OP_fbreg:
+  case llvm::dwarf::DW_OP_piece:
+  case llvm::dwarf::DW_OP_deref_size:
+  case llvm::dwarf::DW_OP_xderef_size:
+  case llvm::dwarf::DW_OP_call2:
+  case llvm::dwarf::DW_OP_call4:
+  case llvm::dwarf::DW_OP_call_ref:
+  case llvm::dwarf::DW_OP_addrx:
+  case llvm::dwarf::DW_OP_constx:
+  case llvm::dwarf::DW_OP_convert:
+  case llvm::dwarf::DW_OP_reinterpret:
+    return 1;
+  case llvm::dwarf::DW_OP_bregx:
+  case llvm::dwarf::DW_OP_bit_piece:
+  case llvm::dwarf::DW_OP_implicit_value:
+  case llvm::dwarf::DW_OP_implicit_pointer:
+  case llvm::dwarf::DW_OP_entry_value:
+  case llvm::dwarf::DW_OP_regval_type:
+  case llvm::dwarf::DW_OP_deref_type:
+  case llvm::dwarf::DW_OP_xderef_type:
+    return 2;
+  case llvm::dwarf::DW_OP_const_type:
+    return 3;
+  default:
+    return 0;
+  }
+}
+
+::mlir::Attribute DIExpressionAttr::parse(AsmParser &parser, Type type) {
----------------
waj334 wrote:

> Is the grouping you implemented in queryNumOpParams necessary? Isn't there an LLVM function we can query to get the number of parameters of an opcode? Overall it seems like this adds quite a bit of complexity and maybe an easy approach could be to just use a flat list for the DIExpression?

Yes this is necessary if you want to parse operations in their textual form, since you would need to know when the next operation starts and I need to know it again when rebuilding the attribute from LLVM IR. LLVM has a much simpler form of this method that I can steal and I can use LLVM's facilities in the importer. 

https://github.com/llvm/llvm-project/pull/73367