From 74a17ec093fc824f45fa5547a65155c93c907b88 Mon Sep 17 00:00:00 2001
From: tyfkda <tyfkda@gmail.com>
Date: Sun, 3 Dec 2023 09:13:10 +0900
Subject: [PATCH] Refactoring for initializer

---
 src/cc/frontend/initializer.c | 20 +++++++----
 src/cc/frontend/parser.c      | 67 ++++++++++++++++++++---------------
 2 files changed, 52 insertions(+), 35 deletions(-)

diff --git a/src/cc/frontend/initializer.c b/src/cc/frontend/initializer.c
index 2ca2eab85..969aa4da8 100644
--- a/src/cc/frontend/initializer.c
+++ b/src/cc/frontend/initializer.c
@@ -163,6 +163,10 @@ static int compare_desig_start(const void *a, const void *b) {
   return d > 0 ? 1 : d < 0 ? -1 : 0;
 }
 
+typedef struct {
+  int index;
+} InitFlattener;
+
 static Initializer *flatten_array_initializer(Initializer *init) {
   // Check whether IK_DOT or IK_ARR exists.
   int i = 0, len = init->multi->len;
@@ -238,7 +242,9 @@ static bool is_multi_type(enum TypeKind kind) {
 
 static Initializer *flatten_initializer_multi0(Type *type, Initializer *init);
 
-static Initializer *flatten_initializer_multi(Type *type, Initializer *init, int *pindex) {
+static Initializer *flatten_initializer_multi(InitFlattener *flattener, Type *type, Initializer *init) {
+  int *const pindex = &flattener->index;
+
   assert(init != NULL);
   switch (init->kind) {
   case IK_SINGLE:
@@ -342,7 +348,7 @@ static Initializer *flatten_initializer_multi(Type *type, Initializer *init, int
             assert(mt->kind == TY_ARRAY);
             mt->pa.length = -1;
           }
-          value = flatten_initializer_multi(mt, init, pindex);
+          value = flatten_initializer_multi(flattener, mt, init);
         }
         values[midx++] = value;
 
@@ -381,7 +387,7 @@ static Initializer *flatten_initializer_multi(Type *type, Initializer *init, int
         } else {
           if (type->pa.length >= 0 && eidx >= type->pa.length)
             break;
-          elem_init = flatten_initializer_multi(elem_type, init, pindex);
+          elem_init = flatten_initializer_multi(flattener, elem_type, init);
         }
         vec_push(elems, elem_init);
         ++eidx;
@@ -400,14 +406,14 @@ static Initializer *flatten_initializer_multi0(Type *type, Initializer *init) {
   if (type->kind == TY_ARRAY)
     init = flatten_array_initializer(init);
 
-  int index = -1;
-  Initializer *flat = flatten_initializer_multi(type, init, &index);
+  InitFlattener flattener = { .index = -1 };
+  Initializer *flat = flatten_initializer_multi(&flattener, type, init);
   switch (type->kind) {
   case TY_ARRAY:
   case TY_STRUCT:
-    if (index < init->multi->len) {
+    if (flattener.index < init->multi->len) {
       const char *tstr = type->kind == TY_ARRAY ? "array" : "struct";
-      parse_error(PE_WARNING, ((Initializer*)init->multi->data[index])->token,
+      parse_error(PE_WARNING, ((Initializer*)init->multi->data[flattener.index])->token,
                   "Excess elements in %s initializer", tstr);
     }
     break;
diff --git a/src/cc/frontend/parser.c b/src/cc/frontend/parser.c
index 606eb1e06..73813d38d 100644
--- a/src/cc/frontend/parser.c
+++ b/src/cc/frontend/parser.c
@@ -77,6 +77,41 @@ extern inline void check_goto_labels(Function *func) {
 
 //
 
+static Initializer *parse_initializer_multi(void) {
+  Initializer *init = NULL;
+  const Token *tok;
+  if (match(TK_DOT)) {  // .member=value
+    Token *ident = consume(TK_IDENT, "ident expected for dotted initializer");
+    Initializer *value = parse_initializer_multi();
+    if (value == NULL) {
+      consume(TK_ASSIGN, "`=' expected for dotted initializer");
+      value = parse_initializer();
+    }
+    if (ident != NULL) {
+      init = new_initializer(IK_DOT, ident);
+      init->dot.name = ident->ident;
+      init->dot.value = value;
+    }
+  } else if ((tok = match(TK_LBRACKET)) != NULL) {
+    Expr *expr = parse_const_fixnum();
+    size_t index = 0;
+    if (expr->fixnum < 0)
+      parse_error(PE_NOFATAL, expr->token, "non negative integer required");
+    else
+      index = expr->fixnum;
+    consume(TK_RBRACKET, "`]' expected");
+    Initializer *value = parse_initializer_multi();
+    if (value == NULL) {
+      match(TK_ASSIGN);  // both accepted: `[1] = 2`, and `[1] 2`
+      value = parse_initializer();
+    }
+    init = new_initializer(IK_ARR, tok);
+    init->arr.index = index;
+    init->arr.value = value;
+  }
+  return init;
+}
+
 Initializer *parse_initializer(void) {
   Initializer *result;
   const Token *lblace_tok;
@@ -84,35 +119,11 @@ Initializer *parse_initializer(void) {
     Vector *multi = new_vector();
     if (!match(TK_RBRACE)) {
       for (;;) {
-        Initializer *init = NULL;
-        const Token *tok;
-        if (match(TK_DOT)) {  // .member=value
-          Token *ident = consume(TK_IDENT, "ident expected for dotted initializer");
-          consume(TK_ASSIGN, "`=' expected for dotted initializer");
-          Initializer *value = parse_initializer();
-          if (ident != NULL) {
-            init = new_initializer(IK_DOT, ident);
-            init->dot.name = ident->ident;
-            init->dot.value = value;
-          }
-        } else if ((tok = match(TK_LBRACKET)) != NULL) {
-          Expr *expr = parse_const_fixnum();
-          size_t index = 0;
-          if (expr->fixnum < 0)
-            parse_error(PE_NOFATAL, expr->token, "non negative integer required");
-          else
-            index = expr->fixnum;
-          consume(TK_RBRACKET, "`]' expected");
-          match(TK_ASSIGN);  // both accepted: `[1] = 2`, and `[1] 2`
-          Initializer *value = parse_initializer();
-          init = new_initializer(IK_ARR, tok);
-          init->arr.index = index;
-          init->arr.value = value;
-        } else {
+        Initializer *init = parse_initializer_multi();
+        if (init == NULL)
           init = parse_initializer();
-        }
-        if (init != NULL)
-          vec_push(multi, init);
+        assert(init != NULL);
+        vec_push(multi, init);
 
         if (match(TK_COMMA)) {
           if (match(TK_RBRACE))