Fix variable declaration.

parse.c

@@ -90,7 +90,7 @@ static bool is_typename() {
          t->ty == TK_STRUCT;
 }
 
-static Node *decl();
+static Node *declaration();
 
 static void add_members(Type *ty, Vector *members) {
   int off = 0;
@@ -111,7 +111,7 @@ static void add_members(Type *ty, Vector *members) {
   ty->size = roundup(off, ty->align);
 }
 
-static Type *read_type() {
+static Type *decl_specifiers() {
   Token *t = tokens->data[pos++];
 
   if (t->ty == TK_IDENT) {
@@ -142,7 +142,7 @@ static Type *read_type() {
     if (consume('{')) {
       members = new_vec();
       while (!consume('}'))
-        vec_push(members, decl());
+        vec_push(members, declaration());
     }
 
     if (!tag && !members)
@@ -165,8 +165,7 @@ static Type *read_type() {
     return ty;
   }
 
-  pos--;
-  return NULL;
+  bad_token(t, "typename expected");
 }
 
 static Node *new_binop(int op, Node *lhs, Node *rhs) {
@@ -470,17 +469,6 @@ static Node *expr() {
   return new_binop(',', lhs, expr());
 }
 
-static Type *type() {
-  Token *t = tokens->data[pos];
-  Type *ty = read_type();
-  if (!ty)
-    bad_token(t, "typename expected");
-
-  while (consume('*'))
-    ty = ptr_to(ty);
-  return ty;
-}
-
 static Type *read_array(Type *ty) {
   Vector *v = new_vec();
   while (consume('[')) {
@@ -498,35 +486,50 @@ static Type *read_array(Type *ty) {
   return ty;
 }
 
-static Node *decl() {
-  Node *node = calloc(1, sizeof(Node));
-  node->op = ND_VARDEF;
+static Node *declarator(Type *ty);
 
-  // Read the first half of type name (e.g. `int *`).
-  node->ty = type();
+static Node *direct_decl(Type *ty) {
+  Token *t = tokens->data[pos];
+  Node *node;
+  Type *placeholder = calloc(1, sizeof(Type));
 
-  // Read an identifier.
-  node->name = ident();
+  if (t->ty == TK_IDENT) {
+    node = calloc(1, sizeof(Node));
+    node->op = ND_VARDEF;
+    node->ty = placeholder;
+    node->name = ident();
+  } else if (consume('(')) {
+    node = declarator(placeholder);
+    expect(')');
+  } else {
+    bad_token(t, "bad direct-declarator");
+  }
 
   // Read the second half of type name (e.g. `[3][5]`).
-  Token *t = tokens->data[pos];
-  node->ty = read_array(node->ty);
-  if (node->ty->ty == VOID)
-    bad_token(t, "void variable");
+  *placeholder = *read_array(ty);
 
   // Read an initializer.
   if (consume('='))
     node->init = assign();
+  return node;
+}
+
+static Node *declarator(Type *ty) {
+  while (consume('*'))
+    ty = ptr_to(ty);
+  return direct_decl(ty);
+}
+
+static Node *declaration() {
+  Type *ty = decl_specifiers();
+  Node *node = declarator(ty);
   expect(';');
   return node;
 }
 
-static Node *param() {
-  Node *node = calloc(1, sizeof(Node));
-  node->op = ND_VARDEF;
-  node->ty = type();
-  node->name = ident();
-  return node;
+static Node *param_declaration() {
+  Type *ty = decl_specifiers();
+  return declarator(ty);
 }
 
 static Node *expr_stmt() {
@@ -541,7 +544,7 @@ static Node *stmt() {
 
   switch (t->ty) {
   case TK_TYPEDEF: {
-    Node *node = decl();
+    Node *node = declaration();
     assert(node->name);
     map_put(env->typedefs, node->name, node->ty);
     return &null_stmt;
@@ -562,7 +565,7 @@ static Node *stmt() {
     expect('(');
 
     if (is_typename())
-      node->init = decl();
+      node->init = declaration();
     else if (consume(';'))
       node->init = &null_stmt;
     else
@@ -616,7 +619,7 @@ static Node *stmt() {
   default:
     pos--;
     if (is_typename())
-      return decl();
+      return declaration();
     return expr_stmt();
   }
 }
@@ -637,11 +640,9 @@ static Node *toplevel() {
   bool is_typedef = consume(TK_TYPEDEF);
   bool is_extern = consume(TK_EXTERN);
 
-  Token *t = tokens->data[pos];
-
-  Type *ty = type();
-  if (!ty)
-    bad_token(t, "typename expected");
+  Type *ty = decl_specifiers();
+  while (consume('*'))
+    ty = ptr_to(ty);
 
   char *name = ident();
 
@@ -654,15 +655,16 @@ static Node *toplevel() {
     node->args = new_vec();
 
     if (!consume(')')) {
-      vec_push(node->args, param());
+      vec_push(node->args, param_declaration());
       while (consume(','))
-        vec_push(node->args, param());
+        vec_push(node->args, param_declaration());
       expect(')');
     }
 
+    Token *t = tokens->data[pos];
     expect('{');
     if (is_typedef)
-      bad_token(t, "typedef %s has function definition");
+      bad_token(t, "typedef has function definition");
     node->body = compound_stmt();
     return node;
   }

test/gcc.c

@@ -1,7 +1,3 @@
 // This file is compiled by gcc.
 
 int global_arr[1] = {5};
-
-int add2(int a[][2]) {
-  return a[0][0] + a[1][0];
-}

test/test.c

@@ -18,6 +18,7 @@ int two() { return 2; }
 int plus(int x, int y) { return x + y; }
 int mul(int x, int y) { return x * y; }
 int add(int a, int b, int c, int d, int e, int f) { return a+b+c+d+e+f; }
+int add2(int (*a)[2]) { return a[0][0] + a[1][0]; }
 
 int var1;
 int var2[5];