src: normalize malloc, realloc

malloc(0) and realloc(ptr, 0) have implementation-defined behavior in
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.

- Introduce node::malloc, node::realloc and node::calloc that should
  be used throught our source.
- Update all existing node source files to use the new functions
  instead of the native allocation functions.

Fixes: https://github.com/nodejs/node/issues/7549
PR-URL: https://github.com/nodejs/node/pull/7564
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 4 insertions, 8 deletions

diff --git a/src/node_buffer.cc b/src/node_buffer.cc
index ad06dd0233..4baa8d9ac6 100644
--- a/src/node_buffer.cc
+++ b/src/node_buffer.cc
@@ -50,7 +50,7 @@
   size_t length = end - start;
 
 #define BUFFER_MALLOC(length)                                               \
-  zero_fill_all_buffers ? calloc(length, 1) : malloc(length)
+  zero_fill_all_buffers ? node::Calloc(length, 1) : node::Malloc(length)
 
 #if defined(__GNUC__) || defined(__clang__)
 #define BSWAP_INTRINSIC_2(x) __builtin_bswap16(x)
@@ -265,10 +265,6 @@ MaybeLocal<Object> New(Isolate* isolate,
   size_t actual = 0;
   char* data = nullptr;
 
-  // malloc(0) and realloc(ptr, 0) have implementation-defined behavior in
-  // 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.
   if (length > 0) {
     data = static_cast<char*>(BUFFER_MALLOC(length));
 
@@ -282,7 +278,7 @@ MaybeLocal<Object> New(Isolate* isolate,
       free(data);
       data = nullptr;
     } else if (actual < length) {
-      data = static_cast<char*>(realloc(data, actual));
+      data = static_cast<char*>(node::Realloc(data, actual));
       CHECK_NE(data, nullptr);
     }
   }
@@ -361,7 +357,7 @@ MaybeLocal<Object> Copy(Environment* env, const char* data, size_t length) {
   void* new_data;
   if (length > 0) {
     CHECK_NE(data, nullptr);
-    new_data = malloc(length);
+    new_data = node::Malloc(length);
     if (new_data == nullptr)
       return Local<Object>();
     memcpy(new_data, data, length);
@@ -1083,7 +1079,7 @@ void IndexOfString(const FunctionCallbackInfo<Value>& args) {
                           offset,
                           is_forward);
   } else if (enc == LATIN1) {
-    uint8_t* needle_data = static_cast<uint8_t*>(malloc(needle_length));
+    uint8_t* needle_data = static_cast<uint8_t*>(node::Malloc(needle_length));
     if (needle_data == nullptr) {
       return args.GetReturnValue().Set(-1);
     }