[PATCH] D133926: [DebugInfo] Allow non-stack_value variadic expressions and use in DBG_INSTR_REF

[Stephen Tozer via Phabricator via llvm-commits]

StephenTozer added inline comments.


================
Comment at: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:1140-1145
+  if (Expr->getNumElements() && Expr->isSingleLocationExpression() &&
+      Expr->expr_op_begin()->getOp() == dwarf::DW_OP_LLVM_arg) {
+    SmallVector<uint64_t> Ops(
+        make_range(Expr->elements_begin() + 2, Expr->elements_end()));
+    Expr = DIExpression::get(Expr->getContext(), Ops);
+  }
----------------
jmorse wrote:
> Just to check -- this is purely for printing the informative comments on assembly output, it isn't actually functional, yes?
Correct, this is just removing noise from the patch - even if it was an expression being used somewhere, it'd still have the same meaning either way, just formatted slightly differently.


================
Comment at: llvm/lib/IR/DebugInfoMetadata.cpp:1503-1511
+    // A DW_OP_stack_value comes at the end, but before a DW_OP_LLVM_fragment.
+    if (StackValue) {
+      if (Op.getOp() == dwarf::DW_OP_stack_value)
+        StackValue = false;
+      else if (Op.getOp() == dwarf::DW_OP_LLVM_fragment) {
+        NewOps.push_back(dwarf::DW_OP_stack_value);
+        StackValue = false;
----------------
jmorse wrote:
> Just to confirm, the reason why this wasn't present before was because all variadic expressions had to be stack_value, yes?
Correct - worth noting the only reason they "had" to be stack_value was because they're only naturally produced by salvaging operations that create stack_value expressions, not because there's some inherent incompatibility.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D133926/new/

https://reviews.llvm.org/D133926