Parse record declaration while declaring variable

parser.y

@@ -31,6 +31,7 @@ std::unique_ptr<Type> ResolveType(std::unique_ptr<Type> resolved_type,
 // inserts verbatim to the header file.
 %code requires {
   #include <memory>
+  #include <set>
   #include <string>
   #include <variant>
   #include <vector>
@@ -47,6 +48,9 @@ std::unique_ptr<Type> ResolveType(std::unique_ptr<Type> resolved_type,
   Location Loc(const yy::location& loc) {
     return Location{loc.begin.line, loc.begin.column};
   }
+
+  /// @brief A set that stores unique custom types for every file.
+  std::set<std::string> custom_types;
 }
 
 %skeleton "lalr1.cc"
@@ -420,19 +424,25 @@ decl: declaration_specifiers init_declarator_list_opt SEMICOLON {
       }
     } 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));
-      } else {
-        auto& rec_decl = dynamic_cast<RecordDeclNode&>(*decl);
-        // Initialize record variable.
+      auto& rec_decl = dynamic_cast<RecordDeclNode&>(*decl);
+
+      if (!init_decl_list.empty()) {
         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));
         }
       }
+
+      auto rec_type_id = dynamic_cast<RecordType&>(*rec_decl.type).id();
+      // Insert RecordDeclNode if it is a newly create type.
+      if (custom_types.find(rec_type_id) == custom_types.end()) {
+        // To dump type declarations in front of variable declarations,
+        // insert decl at the beginning of the vector.
+        decl_list.insert(decl_list.begin(), std::move(decl));
+        custom_types.insert(rec_type_id);
+      }
     }
     $$ = std::make_unique<DeclStmtNode>(Loc(@1), std::move(decl_list));
   }

test/codegen/struct.c

@@ -18,5 +18,19 @@ int main() {
   bd1.date = bd1.date + 2;
   __builtin_print(bd1.date);
 
+  struct book {
+    int fiction;
+    int sci_fi;
+    int history;
+  } library = {
+    .fiction = 100,
+    .sci_fi = 50,
+    .history = 500,
+  };
+
+  __builtin_print(library.fiction);
+  __builtin_print(library.sci_fi);
+  __builtin_print(library.history);
+
   return 0;
 }

test/codegen/struct.exp

@@ -2,3 +2,6 @@
 5
 1998
 5
+100
+50
+500

test/codegen/union.c

@@ -21,5 +21,14 @@ int main() {
   __builtin_print(s.circle);
   __builtin_print(s.triangle);
 
+  union gender {
+    int male;
+    int female;
+  } girl = {
+    .female = 1,
+  };
+
+  __builtin_print(girl.female);
+
   return 0;
 }

test/codegen/union.exp

@@ -4,3 +4,4 @@
 4
 4
 4
+1

test/typecheck/struct.c

@@ -27,5 +27,21 @@ int main() {
 
   bd1.date;
 
+  struct animal {
+    int lion;
+    int tiger;
+    int giraffe;
+  } zoo;
+
+  struct book {
+    int fiction;
+    int sci_fi;
+    int history;
+  } library = {
+    .fiction = 100,
+    .sci_fi = 50,
+    .history = 500,
+  };
+
   return 0;
 }

test/typecheck/struct.exp

@@ -52,5 +52,26 @@ TransUnitNode <1:1>
         ExprStmtNode <28:3>
           RecordMemExprNode <28:3> .date: int
             IdExprNode <28:3> bd1: struct birth
-        ReturnStmtNode <30:3>
-          IntConstExprNode <30:10> 0: int
+        DeclStmtNode <30:3>
+          RecordDeclNode <30:10> struct animal definition
+            FieldNode <31:9> lion: int
+            FieldNode <32:9> tiger: int
+            FieldNode <33:9> giraffe: int
+          VarDeclNode <34:5> zoo: struct animal
+        DeclStmtNode <36:3>
+          RecordDeclNode <36:10> struct book definition
+            FieldNode <37:9> fiction: int
+            FieldNode <38:9> sci_fi: int
+            FieldNode <39:9> history: int
+          RecordVarDeclNode <40:5> library: struct book
+            InitExprNode <41:5> int
+              IdDesNode <41:6> fiction
+              IntConstExprNode <41:16> 100: int
+            InitExprNode <41:5> int
+              IdDesNode <42:6> sci_fi
+              IntConstExprNode <42:15> 50: int
+            InitExprNode <41:5> int
+              IdDesNode <43:6> history
+              IntConstExprNode <43:16> 500: int
+        ReturnStmtNode <46:3>
+          IntConstExprNode <46:10> 0: int

test/typecheck/union.c

@@ -26,5 +26,19 @@ int main() {
 
   s.circle;
 
+  union gender {
+    int male;
+    int female;
+  } girl = {
+    .female = 1,
+  };
+
+  union birth_place {
+    int tw;
+    int us;
+  } yt = {
+    .tw = 1,
+  };
+
   return 0;
 }

test/typecheck/union.exp

@@ -53,5 +53,21 @@ TransUnitNode <1:1>
         ExprStmtNode <27:3>
           RecordMemExprNode <27:3> .circle: int
             IdExprNode <27:3> s: union shape
-        ReturnStmtNode <29:3>
-          IntConstExprNode <29:10> 0: int
+        DeclStmtNode <29:3>
+          RecordDeclNode <29:9> union gender definition
+            FieldNode <30:9> male: int
+            FieldNode <31:9> female: int
+          RecordVarDeclNode <32:5> girl: union gender
+            InitExprNode <33:5> int
+              IdDesNode <33:6> female
+              IntConstExprNode <33:15> 1: int
+        DeclStmtNode <36:3>
+          RecordDeclNode <36:9> union birth_place definition
+            FieldNode <37:9> tw: int
+            FieldNode <38:9> us: int
+          RecordVarDeclNode <39:5> yt: union birth_place
+            InitExprNode <40:5> int
+              IdDesNode <40:6> tw
+              IntConstExprNode <40:11> 1: int
+        ReturnStmtNode <43:3>
+          IntConstExprNode <43:10> 0: int