Print an error when trying to read too large of an array.

DbgEng only supports reads with a 32bit size.  (more than 2^32 elements)

Author: SeanCline

include/RemoteType.h

@@ -35,7 +35,7 @@ namespace PyExt::Remote {
 		auto offset() const -> Offset;
 		auto symbolName() const -> std::string;
 		// necessary for x86 because offsets in remote address space are only 32 Bit
-		static auto readOffsetArray(/*const*/ ExtRemoteTyped& remoteArray, unsigned long numElements) -> std::vector<Offset>;
+		static auto readOffsetArray(/*const*/ ExtRemoteTyped& remoteArray, std::uint64_t numElements) -> std::vector<Offset>;
 
 	protected: // Helpers for more derived classes.
 		/// Access to the instance's memory in the debuggee.

src/ExtHelpers.h

@@ -3,6 +3,8 @@
 #include <engextcpp.hpp>
 #include <type_traits>
 #include <vector>
+#include <string>
+#include <limits>
 using namespace std::literals::string_literals;
 
 namespace utils {
@@ -31,16 +33,22 @@ namespace utils {
 
 	// Reads an array of elements pointed to by an ExtRemoteData.
 	template <typename ElemType>
-	auto readArray(/*const*/ ExtRemoteTyped& remoteArray, unsigned long numElements) -> std::vector<ElemType>
+	auto readArray(/*const*/ ExtRemoteTyped& remoteArray, std::uint64_t numElements) -> std::vector<ElemType>
 	{
 		auto remoteData = remoteArray.Dereference();
 		const auto remoteSize = remoteData.GetTypeSize();
 		if (remoteSize != sizeof(ElemType)) {
 			g_Ext->ThrowRemote(E_INVALIDARG, "sizeof(ElemType) does not match size type size for ExtRemoteTyped array read.");
 		}
 
+		const auto arrayExtent = numElements * remoteSize;
+		// ExtRemoteData only supports arrays with 32bit extents, so we have to narrow it.
+		if (numElements > std::numeric_limits<std::uint32_t>::max()) {
+			g_Ext->ThrowRemote(E_BOUNDS, "Could not read array. Size too large.");
+		}
+
 		std::vector<ElemType> buffer(numElements);
-		remoteData.ReadBuffer(buffer.data(), numElements*remoteSize);
+		remoteData.ReadBuffer(buffer.data(), static_cast<std::uint32_t>(arrayExtent));
 		return buffer;
 	}
 

src/PyExt.vcxproj

@@ -63,7 +63,7 @@
       <PrecompiledHeaderFile>pch.h</PrecompiledHeaderFile>
       <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
       <LanguageStandard>stdcpp17</LanguageStandard>
-      <PreprocessorDefinitions>PYEXT_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>PYEXT_DLL;NOMINMAX;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>

src/RemoteType.cpp

@@ -51,7 +51,7 @@ namespace PyExt::Remote {
 	}
 
 
-	auto RemoteType::readOffsetArray(/*const*/ ExtRemoteTyped& remoteArray, unsigned long numElements) -> vector<Offset>
+	auto RemoteType::readOffsetArray(/*const*/ ExtRemoteTyped& remoteArray, std::uint64_t numElements) -> vector<Offset>
 	{
 		auto ptrSize = utils::getPointerSize();
 		switch (ptrSize) {
@@ -63,7 +63,7 @@ namespace PyExt::Remote {
 		}
 		case 8:
 			// x64 - 64 Bit Python
-			return utils::readArray<Offset>(remoteArray, numElements);
+			return utils::readArray<std::uint64_t>(remoteArray, numElements);
 		}
 
 		g_Ext->ThrowInterrupt();