From c33f1fb03ec563caed708bfd8ae85e0282542936 Mon Sep 17 00:00:00 2001
From: Wiktor Garbacz <wiktorg@google.com>
Date: Fri, 18 Sep 2020 07:22:51 -0700
Subject: [PATCH] Simplify casts

Drive-by: check for malloc failure in sapi::v::Array
PiperOrigin-RevId: 332446225
Change-Id: I375ea94845e04dffc3353d70737402daa66ae50a
---
 sandboxed_api/client.cc   |  6 +++---
 sandboxed_api/var_array.h | 25 ++++++++++++-------------
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/sandboxed_api/client.cc b/sandboxed_api/client.cc
index df2b24d..738fc87 100644
--- a/sandboxed_api/client.cc
+++ b/sandboxed_api/client.cc
@@ -254,8 +254,8 @@ void HandleReallocMsg(uintptr_t ptr, uintptr_t size, FuncRet* ret) {
       __sanitizer_get_allocated_size(reinterpret_cast<const void*>(ptr));
 #endif
   ret->ret_type = v::Type::kPointer;
-  ret->int_val = reinterpret_cast<uintptr_t>(
-      realloc(const_cast<void*>(reinterpret_cast<const void*>(ptr)), size));
+  ret->int_val =
+      reinterpret_cast<uintptr_t>(realloc(reinterpret_cast<void*>(ptr), size));
   ret->success = true;
 #ifdef MEMORY_SANITIZER
   // Memory is copied to the pointer using an API that the memory sanitizer
@@ -273,7 +273,7 @@ void HandleReallocMsg(uintptr_t ptr, uintptr_t size, FuncRet* ret) {
 void HandleFreeMsg(uintptr_t ptr, FuncRet* ret) {
   VLOG(1) << "HandleFreeMsg: free(0x" << absl::StrCat(absl::Hex(ptr)) << ")";
 
-  free(const_cast<void*>(reinterpret_cast<const void*>(ptr)));
+  free(reinterpret_cast<void*>(ptr));
   ret->ret_type = v::Type::kVoid;
   ret->success = true;
   ret->int_val = 0ULL;
diff --git a/sandboxed_api/var_array.h b/sandboxed_api/var_array.h
index 60968ba..fcf2da9 100644
--- a/sandboxed_api/var_array.h
+++ b/sandboxed_api/var_array.h
@@ -15,9 +15,11 @@
 #ifndef SANDBOXED_API_VAR_ARRAY_H_
 #define SANDBOXED_API_VAR_ARRAY_H_
 
+#include <algorithm>
 #include <cstring>
 #include <memory>
 
+#include <glog/logging.h>
 #include "absl/base/macros.h"
 #include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
@@ -39,19 +41,19 @@ class Array : public Var, public Pointable {
         nelem_(nelem),
         total_size_(nelem_ * sizeof(T)),
         buffer_owned_(false) {
-    SetLocal(const_cast<void*>(reinterpret_cast<const void*>(arr_)));
+    SetLocal(const_cast<std::remove_const_t<T>*>(arr_));
   }
   // The array is allocated and owned by this object.
   explicit Array(size_t nelem)
-      : arr_(static_cast<T*>(malloc(sizeof(T) * nelem))),
-        nelem_(nelem),
-        total_size_(nelem_ * sizeof(T)),
-        buffer_owned_(true) {
-    SetLocal(const_cast<void*>(reinterpret_cast<const void*>(arr_)));
+      : nelem_(nelem), total_size_(nelem_ * sizeof(T)), buffer_owned_(true) {
+    void* storage = malloc(sizeof(T) * nelem);
+    CHECK(storage != nullptr);
+    SetLocal(storage);
+    arr_ = static_cast<T*>(storage);
   }
   virtual ~Array() {
     if (buffer_owned_) {
-      free(const_cast<void*>(reinterpret_cast<const void*>(arr_)));
+      free(const_cast<std::remove_const_t<T>*>(arr_));
     }
   }
 
@@ -121,7 +123,7 @@ class Array : public Var, public Pointable {
     arr_ = static_cast<T*>(new_addr);
     total_size_ = size;
     nelem_ = size / sizeof(T);
-    SetLocal(arr_);
+    SetLocal(new_addr);
     return absl::OkStatus();
   }
 
@@ -142,7 +144,7 @@ class Array : public Var, public Pointable {
 class CStr : public Array<char> {
  public:
   explicit CStr(char* cstr) : Array<char>(strlen(cstr) + 1) {
-    strcpy(this->GetData(), cstr);  // NOLINT
+    std::copy(cstr, cstr + GetNElem(), GetData());
   }
 
   std::string ToString() const final {
@@ -159,10 +161,7 @@ class ConstCStr : public Array<const char> {
       : Array<const char>(cstr, strlen(cstr) + 1) {}
 
   std::string ToString() const final {
-    if (GetData() == nullptr) {
-      return "CStr: [nullptr]";
-    }
-    return absl::StrCat("CStr: len(w/o NUL):", strlen(GetData()), ", ['",
+    return absl::StrCat("ConstCStr: len(w/o NUL):", strlen(GetData()), ", ['",
                         GetData(), "']");
   }
 };