Fix missing record declaration tests

[leewei05]

My bad, missed this update on previous reviews. The current implementation only consider the case for struct and union variable initialization.

[Lai-YT]

It seems like we have the same issue regarding to unnamed primitive types.
We check whether it declares an identifier or not inside the iteration over the init_decl_list; however, we don't even get into the loop when it doesn't declare an identifier, leading to an empty declaration node:

vitaminc/parser.y

Lines 398 to 405 in 2f6edee

	for (auto& init_decl : init_decl_list) {
	if (init_decl) {
	init_decl->type = ResolveType(type->Clone(), std::move(init_decl->type));
	} else { // unnamed primitive type
	init_decl = std::make_unique<VarDeclNode>(Loc(@1), "", type->Clone());
	}
	decl_list.push_back(std::move(init_decl));
	}

vitaminc/test/typecheck/decl.c

Line 4 in 2f6edee

int;

vitaminc/test/typecheck/decl.exp

Lines 9 to 10 in 2f6edee

	DeclStmtNode <4:3>
	DeclStmtNode <5:3>

Would you mind addressing them together? Here's a possible modification:

    if (std::holds_alternative<std::unique_ptr<Type>>(decl_specifiers)) {
      auto type = std::move(std::get<std::unique_ptr<Type>>(decl_specifiers));
      if (init_decl_list.empty()) {
        // A stand-alone type that doesn't declare any identifier, e.g., `int;`.
        decl_list.push_back(std::make_unique<VarDeclNode>(Loc(@1), "", type->Clone()));
      }

      // Declare primitive identifier.
      for (auto& init_decl : init_decl_list) {
        if (init_decl) {
          init_decl->type = ResolveType(type->Clone(), std::move(init_decl->type));
        }
        decl_list.push_back(std::move(init_decl));
      }
    } else {
      auto decl = std::move(std::get<std::unique_ptr<DeclNode>>(decl_specifiers));
      // A record declaration that doesn't declare any identifier, e.g., `struct point {int x, int y};`.
      if (init_decl_list.empty()) {
        decl_list.push_back(std::move(decl));
      }

      auto* rec_decl = dynamic_cast<RecordDeclNode*>(decl.get());
      // Declare record identifier.
      for (auto& init_decl : init_decl_list) {
        if (init_decl) {
          init_decl->type = ResolveType(rec_decl->type->Clone(), std::move(init_decl->type));
        }
        decl_list.push_back(std::move(init_decl));
      }
    }

       DeclStmtNode <4:3>
+        VarDeclNode <4:3> : int
       DeclStmtNode <5:3>

[Lai-YT]

I just realized there is another issue. If we build a DeclNode with the name "", our code generator is likely to allocate space for it. We need to filter out these empty nodes. It is important to note that Clang doesn't build nodes for declarations that have no effect on the program.

`-FunctionDecl 0x1f690a0 <test/typecheck/decl.c:1:1, line:6:1> line:1:5 main 'int ()'
  `-CompoundStmt 0x1f69558 <col:12, line:6:1>
    |-DeclStmt 0x1f69228 <line:2:3, col:12>
    | `-VarDecl 0x1f691a0 <col:3, col:11> col:7 i 'int' cinit
    |   `-IntegerLiteral 0x1f69208 <col:11> 'int' 0
    |-DeclStmt 0x1f692c0 <line:3:3, col:8>
    | `-VarDecl 0x1f69258 <col:3, col:7> col:7 j 'int'
    `-DeclStmt 0x1f69540 <line:5:3, col:25>
      |-VarDecl 0x1f692f0 <col:3, col:7> col:7 a 'int'
      |-VarDecl 0x1f69370 <col:3, col:14> col:10 b 'int' cinit
      | `-IntegerLiteral 0x1f693d8 <col:14> 'int' 1
      |-VarDecl 0x1f69410 <col:3, col:17> col:17 c 'int'
      `-VarDecl 0x1f69490 <col:3, col:24> col:20 d 'int' cinit
        `-IntegerLiteral 0x1f694f8 <col:24> 'int' 0

[leewei05]

I just realized there is another issue. If we build a DeclNode with the name "", our code generator is likely to allocate space for it. We need to filter out these empty nodes. It is important to note that Clang doesn't build nodes for declarations that have no effect on the program.

Suggest fixing this in a future PR since it's related only to unnamed nodes.

[Lai-YT]

LGTM 😄
We can resolve the code generation issue one day. 🤟