fix(catalyst): variable-length arrays (#275)

Author: NathanWalker

NativeScript/runtime/FFICall.h

@@ -2,117 +2,127 @@
 #define FFICall_h
 
 #include <malloc/malloc.h>
+
 #include <map>
-#include "robin_hood.h"
-#include "Metadata.h"
+
 #include "DataWrapper.h"
+#include "Metadata.h"
 #include "libffi.h"
+#include "robin_hood.h"
 
 namespace tns {
 
 class BaseCall {
-public:
-    BaseCall(uint8_t* buffer, size_t returnOffset = 0)
-        : buffer_(buffer),
-          returnOffset_(returnOffset) {
-    }
+ public:
+  BaseCall(uint8_t* buffer, size_t returnOffset = 0)
+      : buffer_(buffer), returnOffset_(returnOffset) {}
 
-    ~BaseCall() {
-    }
+  ~BaseCall() {}
 
-    inline void* ResultBuffer() {
-        return this->buffer_ + this->returnOffset_;
-    }
+  inline void* ResultBuffer() { return this->buffer_ + this->returnOffset_; }
 
-    template <typename T>
-    inline T& GetResult() {
-        return *static_cast<T*>(this->ResultBuffer());
-    }
-protected:
-    uint8_t* buffer_;
-    size_t returnOffset_;
+  template <typename T>
+  inline T& GetResult() {
+    return *static_cast<T*>(this->ResultBuffer());
+  }
+
+ protected:
+  uint8_t* buffer_;
+  size_t returnOffset_;
 };
 
 class ParametrizedCall {
-public:
-    ParametrizedCall(ffi_cif* cif)
-        : Cif(cif),
-          ReturnOffset(0),
-          StackSize(0) {
-        unsigned int argsCount = cif->nargs;
-        this->StackSize = 0;
-
-        if (argsCount > 0) {
-            this->StackSize = malloc_good_size(sizeof(void* [argsCount]));
-        }
-
-        this->ReturnOffset = this->StackSize;
-
-        this->StackSize += malloc_good_size(std::max(cif->rtype->size, sizeof(ffi_arg)));
-
-        this->ArgValueOffsets.reserve(argsCount);
-        for (size_t i = 0; i < argsCount; i++) {
-            this->ArgValueOffsets.push_back(this->StackSize);
-            ffi_type* argType = cif->arg_types[i];
-            this->StackSize += malloc_good_size(std::max(argType->size, sizeof(ffi_arg)));
-        }
+ public:
+  ParametrizedCall(ffi_cif* cif) : Cif(cif), ReturnOffset(0), StackSize(0) {
+    unsigned int argsCount = cif->nargs;
+    this->StackSize = 0;
+
+    if (argsCount > 0) {
+      // compute total bytes = number of pointers × size of a pointer
+      size_t needed = sizeof(void*) * static_cast<size_t>(argsCount);
+      this->StackSize = malloc_good_size(needed);
     }
 
-    static ParametrizedCall* Get(const TypeEncoding* typeEncoding, const int initialParameterIndex, const int argsCount);
+    this->ReturnOffset = this->StackSize;
 
-    ffi_cif* Cif;
-    size_t ReturnOffset;
-    size_t StackSize;
-    std::vector<size_t> ArgValueOffsets;
-private:
-    static robin_hood::unordered_map<const TypeEncoding*, ParametrizedCall*> callsCache_;
-};
+    this->StackSize +=
+        malloc_good_size(std::max(cif->rtype->size, sizeof(ffi_arg)));
 
-class FFICall: public BaseCall {
-public:
-    FFICall(ParametrizedCall* parametrizedCall): BaseCall(nullptr) {
-        this->returnOffset_ = parametrizedCall->ReturnOffset;
-        this->useDynamicBuffer_ = parametrizedCall->StackSize > 512;
-        if(this->useDynamicBuffer_) {
-            this->buffer_ = reinterpret_cast<uint8_t*>(malloc(parametrizedCall->StackSize));
-        } else {
-            this->buffer_ = reinterpret_cast<uint8_t*>(this->staticBuffer);
-        }
-
-        this->argsArray_ = reinterpret_cast<void**>(this->buffer_);
-        for (size_t i = 0; i < parametrizedCall->Cif->nargs; i++) {
-            this->argsArray_[i] = this->buffer_ + parametrizedCall->ArgValueOffsets[i];
-        }
+    this->ArgValueOffsets.reserve(argsCount);
+    for (size_t i = 0; i < argsCount; i++) {
+      this->ArgValueOffsets.push_back(this->StackSize);
+      ffi_type* argType = cif->arg_types[i];
+      this->StackSize +=
+          malloc_good_size(std::max(argType->size, sizeof(ffi_arg)));
     }
+  }
 
-    ~FFICall() {
-        if(this->useDynamicBuffer_) {
-          free(this->buffer_);
-        }
-    }
+  static ParametrizedCall* Get(const TypeEncoding* typeEncoding,
+                               const int initialParameterIndex,
+                               const int argsCount);
 
-    /**
-     When calling this, always make another call to DisposeFFIType with the same parameters
-     */
-    static ffi_type* GetArgumentType(const TypeEncoding* typeEncoding, bool isStructMember = false);
-    static void DisposeFFIType(ffi_type* type, const TypeEncoding* typeEncoding);
-    static StructInfo GetStructInfo(const StructMeta* structMeta, std::string structName = "");
-    static StructInfo GetStructInfo(size_t fieldsCount, const TypeEncoding* fieldEncoding, const String* fieldNames, std::string structName = "");
+  ffi_cif* Cif;
+  size_t ReturnOffset;
+  size_t StackSize;
+  std::vector<size_t> ArgValueOffsets;
+
+ private:
+  static robin_hood::unordered_map<const TypeEncoding*, ParametrizedCall*>
+      callsCache_;
+};
+
+class FFICall : public BaseCall {
+ public:
+  FFICall(ParametrizedCall* parametrizedCall) : BaseCall(nullptr) {
+    this->returnOffset_ = parametrizedCall->ReturnOffset;
+    this->useDynamicBuffer_ = parametrizedCall->StackSize > 512;
+    if (this->useDynamicBuffer_) {
+      this->buffer_ =
+          reinterpret_cast<uint8_t*>(malloc(parametrizedCall->StackSize));
+    } else {
+      this->buffer_ = reinterpret_cast<uint8_t*>(this->staticBuffer);
+    }
 
-    inline void* ArgumentBuffer(unsigned index) {
-        return this->argsArray_[index];
+    this->argsArray_ = reinterpret_cast<void**>(this->buffer_);
+    for (size_t i = 0; i < parametrizedCall->Cif->nargs; i++) {
+      this->argsArray_[i] =
+          this->buffer_ + parametrizedCall->ArgValueOffsets[i];
     }
+  }
 
-    inline void** ArgsArray() {
-        return this->argsArray_;
+  ~FFICall() {
+    if (this->useDynamicBuffer_) {
+      free(this->buffer_);
     }
-private:
-    static robin_hood::unordered_map<std::string, StructInfo> structInfosCache_;
-    void** argsArray_;
-    bool useDynamicBuffer_;
-    uint8_t staticBuffer[512];
+  }
+
+  /**
+   When calling this, always make another call to DisposeFFIType with the same
+   parameters
+   */
+  static ffi_type* GetArgumentType(const TypeEncoding* typeEncoding,
+                                   bool isStructMember = false);
+  static void DisposeFFIType(ffi_type* type, const TypeEncoding* typeEncoding);
+  static StructInfo GetStructInfo(const StructMeta* structMeta,
+                                  std::string structName = "");
+  static StructInfo GetStructInfo(size_t fieldsCount,
+                                  const TypeEncoding* fieldEncoding,
+                                  const String* fieldNames,
+                                  std::string structName = "");
+
+  inline void* ArgumentBuffer(unsigned index) {
+    return this->argsArray_[index];
+  }
+
+  inline void** ArgsArray() { return this->argsArray_; }
+
+ private:
+  static robin_hood::unordered_map<std::string, StructInfo> structInfosCache_;
+  void** argsArray_;
+  bool useDynamicBuffer_;
+  uint8_t staticBuffer[512];
 };
 
-}
+}  // namespace tns
 
 #endif /* FFICall_h */