src: pass desired return type to allocators

Pass the desired return type directly to the allocation functions,
so that the resulting `static_cast` from `void*` becomes unneccessary
and the return type can be use as a reasonable default value for the
`size` parameter.

Backport-PR-URL: #16587
PR-URL: #8482
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Ilkka Myller <ilkka.myller@nodefield.com>

Author: addaleax

src/cares_wrap.cc

@@ -175,8 +175,7 @@ static void ares_poll_close_cb(uv_handle_t* watcher) {
 
 /* Allocates and returns a new node_ares_task */
 static node_ares_task* ares_task_create(Environment* env, ares_socket_t sock) {
-  node_ares_task* task =
-    static_cast<node_ares_task*>(node::Malloc(sizeof(*task)));
+  auto task = node::Malloc<node_ares_task>(1);
 
   if (task == nullptr) {
     /* Out of memory. */
@@ -329,11 +328,10 @@ void cares_wrap_hostent_cpy(struct hostent* dest, struct hostent* src) {
       alias_count++) {
   }
 
-  dest->h_aliases = static_cast<char**>(node::Malloc((alias_count + 1) *
-                                                           sizeof(char*)));
+  dest->h_aliases = node::Malloc<char*>(alias_count + 1);
   for (size_t i = 0; i < alias_count; i++) {
     cur_alias_length = strlen(src->h_aliases[i]);
-    dest->h_aliases[i] = static_cast<char*>(node::Malloc(cur_alias_length + 1));
+    dest->h_aliases[i] = node::Malloc(cur_alias_length + 1);
     memcpy(dest->h_aliases[i], src->h_aliases[i], cur_alias_length + 1);
   }
   dest->h_aliases[alias_count] = nullptr;
@@ -345,10 +343,9 @@ void cares_wrap_hostent_cpy(struct hostent* dest, struct hostent* src) {
       list_count++) {
   }
 
-  dest->h_addr_list = static_cast<char**>(node::Malloc((list_count + 1) *
-                                                             sizeof(char*)));
+  dest->h_addr_list = node::Malloc<char*>(list_count + 1);
   for (size_t i = 0; i < list_count; i++) {
-    dest->h_addr_list[i] = static_cast<char*>(node::Malloc(src->h_length));
+    dest->h_addr_list[i] = node::Malloc(src->h_length);
     memcpy(dest->h_addr_list[i], src->h_addr_list[i], src->h_length);
   }
   dest->h_addr_list[list_count] = nullptr;
@@ -507,7 +504,7 @@ class QueryWrap : public AsyncWrap {
 
     unsigned char* buf_copy = nullptr;
     if (status == ARES_SUCCESS) {
-      buf_copy = static_cast<unsigned char*>(node::Malloc(answer_len));
+      buf_copy = node::Malloc<unsigned char>(answer_len);
       memcpy(buf_copy, answer_buf, answer_len);
     }
 
@@ -534,7 +531,7 @@ class QueryWrap : public AsyncWrap {
 
     struct hostent* host_copy = nullptr;
     if (status == ARES_SUCCESS) {
-      host_copy = static_cast<hostent*>(node::Malloc(sizeof(hostent)));
+      host_copy = node::Malloc<hostent>(1);
       cares_wrap_hostent_cpy(host_copy, host);
     }
 

src/node.cc

@@ -1054,7 +1054,7 @@ void* ArrayBufferAllocator::Allocate(size_t size) {
   if (env_ == nullptr ||
       !env_->array_buffer_allocator_info()->no_zero_fill() ||
       zero_fill_all_buffers)
-    return node::Calloc(size, 1);
+    return node::Calloc(size);
   env_->array_buffer_allocator_info()->reset_fill_flag();
   return node::Malloc(size);
 }

src/node_buffer.cc

@@ -48,14 +48,20 @@
   THROW_AND_RETURN_IF_OOB(end <= end_max);                                  \
   size_t length = end - start;
 
-#define BUFFER_MALLOC(length)                                               \
-  zero_fill_all_buffers ? node::Calloc(length, 1) : node::Malloc(length)
-
 namespace node {
 
 // if true, all Buffer and SlowBuffer instances will automatically zero-fill
 bool zero_fill_all_buffers = false;
 
+namespace {
+
+inline void* BufferMalloc(size_t length) {
+  return zero_fill_all_buffers ? node::Calloc(length) :
+                                 node::Malloc(length);
+}
+
+}  // namespace
+
 namespace Buffer {
 
 using v8::ArrayBuffer;
@@ -234,7 +240,7 @@ MaybeLocal<Object> New(Isolate* isolate,
   char* data = nullptr;
 
   if (length > 0) {
-    data = static_cast<char*>(BUFFER_MALLOC(length));
+    data = static_cast<char*>(BufferMalloc(length));
 
     if (data == nullptr)
       return Local<Object>();
@@ -246,7 +252,7 @@ MaybeLocal<Object> New(Isolate* isolate,
       free(data);
       data = nullptr;
     } else if (actual < length) {
-      data = static_cast<char*>(node::Realloc(data, actual));
+      data = node::Realloc(data, actual);
       CHECK_NE(data, nullptr);
     }
   }
@@ -280,7 +286,7 @@ MaybeLocal<Object> New(Environment* env, size_t length) {
 
   void* data;
   if (length > 0) {
-    data = BUFFER_MALLOC(length);
+    data = BufferMalloc(length);
     if (data == nullptr)
       return Local<Object>();
   } else {
@@ -1063,7 +1069,7 @@ void IndexOfString(const FunctionCallbackInfo<Value>& args) {
                           offset,
                           is_forward);
   } else if (enc == LATIN1) {
-    uint8_t* needle_data = static_cast<uint8_t*>(node::Malloc(needle_length));
+    uint8_t* needle_data = node::Malloc<uint8_t>(needle_length);
     if (needle_data == nullptr) {
       return args.GetReturnValue().Set(-1);
     }

src/node_crypto.cc

@@ -2386,7 +2386,7 @@ int SSLWrap<Base>::TLSExtStatusCallback(SSL* s, void* arg) {
     size_t len = Buffer::Length(obj);
 
     // OpenSSL takes control of the pointer after accepting it
-    char* data = reinterpret_cast<char*>(node::Malloc(len));
+    char* data = node::Malloc(len);
     CHECK_NE(data, nullptr);
     memcpy(data, resp, len);
 
@@ -3466,7 +3466,7 @@ bool CipherBase::GetAuthTag(char** out, unsigned int* out_len) const {
   if (initialised_ || kind_ != kCipher || !auth_tag_)
     return false;
   *out_len = auth_tag_len_;
-  *out = static_cast<char*>(node::Malloc(auth_tag_len_));
+  *out = node::Malloc(auth_tag_len_);
   CHECK_NE(*out, nullptr);
   memcpy(*out, auth_tag_, auth_tag_len_);
   return true;
@@ -5138,7 +5138,7 @@ void ECDH::ComputeSecret(const FunctionCallbackInfo<Value>& args) {
   // NOTE: field_size is in bits
   int field_size = EC_GROUP_get_degree(ecdh->group_);
   size_t out_len = (field_size + 7) / 8;
-  char* out = static_cast<char*>(node::Malloc(out_len));
+  char* out = node::Malloc(out_len);
   CHECK_NE(out, nullptr);
 
   int r = ECDH_compute_key(out, out_len, pub, ecdh->key_, nullptr);
@@ -5174,7 +5174,7 @@ void ECDH::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
   if (size == 0)
     return env->ThrowError("Failed to get public key length");
 
-  unsigned char* out = static_cast<unsigned char*>(node::Malloc(size));
+  unsigned char* out = node::Malloc<unsigned char>(size);
   CHECK_NE(out, nullptr);
 
   int r = EC_POINT_point2oct(ecdh->group_, pub, form, out, size, nullptr);
@@ -5200,7 +5200,7 @@ void ECDH::GetPrivateKey(const FunctionCallbackInfo<Value>& args) {
     return env->ThrowError("Failed to get ECDH private key");
 
   int size = BN_num_bytes(b);
-  unsigned char* out = static_cast<unsigned char*>(node::Malloc(size));
+  unsigned char* out = node::Malloc<unsigned char>(size);
   CHECK_NE(out, nullptr);
 
   if (size != BN_bn2bin(b, out)) {
@@ -5333,7 +5333,7 @@ class PBKDF2Request : public AsyncWrap {
         saltlen_(saltlen),
         salt_(salt),
         keylen_(keylen),
-        key_(static_cast<char*>(node::Malloc(keylen))),
+        key_(node::Malloc(keylen)),
         iter_(iter) {
     if (key() == nullptr)
       FatalError("node::PBKDF2Request()", "Out of Memory");
@@ -5496,7 +5496,7 @@ void PBKDF2(const FunctionCallbackInfo<Value>& args) {
 
   THROW_AND_RETURN_IF_NOT_BUFFER(args[1], "Salt");
 
-  pass = static_cast<char*>(node::Malloc(passlen));
+  pass = node::Malloc(passlen);
   if (pass == nullptr) {
     FatalError("node::PBKDF2()", "Out of Memory");
   }
@@ -5508,7 +5508,7 @@ void PBKDF2(const FunctionCallbackInfo<Value>& args) {
     goto err;
   }
 
-  salt = static_cast<char*>(node::Malloc(saltlen));
+  salt = node::Malloc(saltlen);
   if (salt == nullptr) {
     FatalError("node::PBKDF2()", "Out of Memory");
   }
@@ -5601,7 +5601,7 @@ class RandomBytesRequest : public AsyncWrap {
       : AsyncWrap(env, object, AsyncWrap::PROVIDER_CRYPTO),
         error_(0),
         size_(size),
-        data_(static_cast<char*>(node::Malloc(size))) {
+        data_(node::Malloc(size)) {
     if (data() == nullptr)
       FatalError("node::RandomBytesRequest()", "Out of Memory");
     Wrap(object, this);
@@ -5828,8 +5828,7 @@ void GetCurves(const FunctionCallbackInfo<Value>& args) {
   EC_builtin_curve* curves;
 
   if (num_curves) {
-    curves = static_cast<EC_builtin_curve*>(node::Malloc(sizeof(*curves),
-                                                         num_curves));
+    curves = node::Malloc<EC_builtin_curve>(num_curves);
 
     CHECK_NE(curves, nullptr);
 

src/stream_wrap.cc

@@ -148,7 +148,7 @@ void StreamWrap::OnAlloc(uv_handle_t* handle,
 
 
 void StreamWrap::OnAllocImpl(size_t size, uv_buf_t* buf, void* ctx) {
-  buf->base = static_cast<char*>(node::Malloc(size));
+  buf->base = node::Malloc(size);
   buf->len = size;
 
   if (buf->base == nullptr && size > 0) {
@@ -204,7 +204,7 @@ void StreamWrap::OnReadImpl(ssize_t nread,
     return;
   }
 
-  char* base = static_cast<char*>(node::Realloc(buf->base, nread));
+  char* base = node::Realloc(buf->base, nread);
   CHECK_LE(static_cast<size_t>(nread), buf->len);
 
   if (pending == UV_TCP) {

src/string_bytes.cc

@@ -53,8 +53,7 @@ class ExternString: public ResourceType {
     if (length == 0)
       return scope.Escape(String::Empty(isolate));
 
-    TypeName* new_data =
-        static_cast<TypeName*>(node::Malloc(length, sizeof(*new_data)));
+    TypeName* new_data = node::Malloc<TypeName>(length);
     if (new_data == nullptr) {
       return Local<String>();
     }
@@ -610,7 +609,7 @@ Local<Value> StringBytes::Encode(Isolate* isolate,
 
     case ASCII:
       if (contains_non_ascii(buf, buflen)) {
-        char* out = static_cast<char*>(node::Malloc(buflen));
+        char* out = node::Malloc(buflen);
         if (out == nullptr) {
           return Local<String>();
         }
@@ -645,7 +644,7 @@ Local<Value> StringBytes::Encode(Isolate* isolate,
 
     case BASE64: {
       size_t dlen = base64_encoded_size(buflen);
-      char* dst = static_cast<char*>(node::Malloc(dlen));
+      char* dst = node::Malloc(dlen);
       if (dst == nullptr) {
         return Local<String>();
       }
@@ -664,7 +663,7 @@ Local<Value> StringBytes::Encode(Isolate* isolate,
 
     case HEX: {
       size_t dlen = buflen * 2;
-      char* dst = static_cast<char*>(node::Malloc(dlen));
+      char* dst = node::Malloc(dlen);
       if (dst == nullptr) {
         return Local<String>();
       }

src/tls_wrap.cc

@@ -663,7 +663,7 @@ void TLSWrap::OnDestructImpl(void* ctx) {
 
 
 void TLSWrap::OnAllocSelf(size_t suggested_size, uv_buf_t* buf, void* ctx) {
-  buf->base = static_cast<char*>(node::Malloc(suggested_size));
+  buf->base = node::Malloc(suggested_size);
   CHECK_NE(buf->base, nullptr);
   buf->len = suggested_size;
 }

src/udp_wrap.cc

@@ -373,7 +373,7 @@ void UDPWrap::OnSend(uv_udp_send_t* req, int status) {
 void UDPWrap::OnAlloc(uv_handle_t* handle,
                       size_t suggested_size,
                       uv_buf_t* buf) {
-  buf->base = static_cast<char*>(node::Malloc(suggested_size));
+  buf->base = node::Malloc(suggested_size);
   buf->len = suggested_size;
 
   if (buf->base == nullptr && suggested_size > 0) {
@@ -415,7 +415,7 @@ void UDPWrap::OnRecv(uv_udp_t* handle,
     return;
   }
 
-  char* base = static_cast<char*>(node::Realloc(buf->base, nread));
+  char* base = node::Realloc(buf->base, nread);
   argv[2] = Buffer::New(env, base, nread).ToLocalChecked();
   argv[3] = AddressToJS(env, addr);
   wrap->MakeCallback(env->onmessage_string(), arraysize(argv), argv);

src/util-inl.h

@@ -335,29 +335,30 @@ inline size_t MultiplyWithOverflowCheck(size_t a, size_t b) {
 // that the standard allows them to either return a unique pointer or a
 // nullptr for zero-sized allocation requests.  Normalize by always using
 // a nullptr.
-void* Realloc(void* pointer, size_t n, size_t size) {
-  size_t full_size = MultiplyWithOverflowCheck(size, n);
+template <typename T>
+T* Realloc(T* pointer, size_t n) {
+  size_t full_size = MultiplyWithOverflowCheck(sizeof(T), n);
 
   if (full_size == 0) {
     free(pointer);
     return nullptr;
   }
 
-  return realloc(pointer, full_size);
+  return static_cast<T*>(realloc(pointer, full_size));
 }
 
 // As per spec realloc behaves like malloc if passed nullptr.
-void* Malloc(size_t n, size_t size) {
+template <typename T>
+T* Malloc(size_t n) {
   if (n == 0) n = 1;
-  if (size == 0) size = 1;
-  return Realloc(nullptr, n, size);
+  return Realloc<T>(nullptr, n);
 }
 
-void* Calloc(size_t n, size_t size) {
+template <typename T>
+T* Calloc(size_t n) {
   if (n == 0) n = 1;
-  if (size == 0) size = 1;
-  MultiplyWithOverflowCheck(size, n);
-  return calloc(n, size);
+  MultiplyWithOverflowCheck(sizeof(T), n);
+  return static_cast<T*>(calloc(n, sizeof(T)));
 }
 
 }  // namespace node

src/util.h

@@ -31,9 +31,16 @@ namespace node {
 // that the standard allows them to either return a unique pointer or a
 // nullptr for zero-sized allocation requests.  Normalize by always using
 // a nullptr.
-inline void* Realloc(void* pointer, size_t n, size_t size = 1);
-inline void* Malloc(size_t n, size_t size = 1);
-inline void* Calloc(size_t n, size_t size = 1);
+template <typename T>
+inline T* Realloc(T* pointer, size_t n);
+template <typename T>
+inline T* Malloc(size_t n);
+template <typename T>
+inline T* Calloc(size_t n);
+
+// Shortcuts for char*.
+inline char* Malloc(size_t n) { return Malloc<char>(n); }
+inline char* Calloc(size_t n) { return Calloc<char>(n); }
 
 #ifdef __GNUC__
 #define NO_RETURN __attribute__((noreturn))
@@ -294,7 +301,7 @@ class MaybeStackBuffer {
     if (storage <= kStackStorageSize) {
       buf_ = buf_st_;
     } else {
-      buf_ = static_cast<T*>(Malloc(sizeof(T), storage));
+      buf_ = Malloc<T>(storage);
       CHECK_NE(buf_, nullptr);
     }
 

test/cctest/test_util.cc

@@ -92,14 +92,16 @@ TEST(UtilTest, ToLower) {
 
 TEST(UtilTest, Malloc) {
   using node::Malloc;
+  EXPECT_NE(nullptr, Malloc<char>(0));
+  EXPECT_NE(nullptr, Malloc<char>(1));
   EXPECT_NE(nullptr, Malloc(0));
   EXPECT_NE(nullptr, Malloc(1));
 }
 
 TEST(UtilTest, Calloc) {
   using node::Calloc;
-  EXPECT_NE(nullptr, Calloc(0, 0));
-  EXPECT_NE(nullptr, Calloc(1, 0));
-  EXPECT_NE(nullptr, Calloc(0, 1));
-  EXPECT_NE(nullptr, Calloc(1, 1));
+  EXPECT_NE(nullptr, Calloc<char>(0));
+  EXPECT_NE(nullptr, Calloc<char>(1));
+  EXPECT_NE(nullptr, Calloc(0));
+  EXPECT_NE(nullptr, Calloc(1));
 }