[PATCH] D143410: [Serialization] Add support for (de)serializing #pragma pack

[Dustin L. Howett via Phabricator via cfe-commits]

DHowett-MSFT added a comment.

While this fixes the assertion failure and the immediate issue of whether packing _works_ inside delay-parsed templates in a PCH, it does reveal a follow-on issue that I can't quite trace out.

  c++
  template <typename T>
  void foo() {
  #pragma pack(push, 1)
  #pragma pack(show)
  #pragma pack(pop)
  }

results in...

  unterminated '#pragma pack (push, ...)' at end of file

I've stepped through ASTReader and verified that we do get all three expected pack pragma nodes

  {PSK_Push, ..., 1}
  {PSK_Show}
  {PSK_Pop, ...}

suggesting that there's something later down the line that messes up the pack stack.



================
Comment at: clang/test/PCH/delayed-template-with-pragma-pack.cpp:14
+int func() {
+#pragma pack(push, 1)
+  struct s { short a; T b; };
----------------
mikerice wrote:
> Your test should include testing of the slot string too, so we are sure all fields are serialized and restored correctly. Otherwise this looks reasonable to me.
So, I've identified an additional wrinkle...

Unlike `#pragma omp`, `#pragma pack` and `... align` don't show up in the AST dump/reprint and I cannot verify their continued existence; this is true _even without delayed template expansion or PCH generation._

alignment/packing seem to not be stored as Attrs, so they don't get printed via attr print on the AST nodes or (prettily) via the tablegen-generated pretty printers.

Fixing this is somewhat beyond me at the moment. :)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D143410/new/

https://reviews.llvm.org/D143410