Fix inject problems (#820)

* CoreCLR: resolve and load nethost on demand instead of requiring it on load

* Remove nethost loading from C# side

* Added option to not chain Process.Dispose; see for last error only if result is empty

lib/CoreCLR/CoreCLR.cpp

@@ -2,12 +2,14 @@
 
 #include "CoreCLR.h"
 #include <Windows.h>
+#include <filesystem>
 #include <iostream>
 #include "nethost/nethost.h"
 
-#pragma comment(lib, "nethost/libnethost.lib")
-
-CoreCLR::CoreCLR() {}
+CoreCLR::CoreCLR(void* calling_module)
+    : m_calling_module(calling_module)
+{
+}
 
 /* Core public functions */
 int CoreCLR::load_hostfxr()
@@ -18,19 +20,43 @@ int CoreCLR::load_hostfxr()
 int CoreCLR::load_hostfxr(const struct get_hostfxr_parameters* parameters)
 {
     // Get the path to CoreCLR's hostfxr
+    std::wstring calling_module_path(MAX_PATH, L'\0');
+    
+    do
+    {
+        calling_module_path.resize(GetModuleFileNameW(static_cast<HMODULE>(m_calling_module), &calling_module_path[0], static_cast<DWORD>(calling_module_path.size())));
+    }
+    while (!calling_module_path.empty() && GetLastError() == ERROR_INSUFFICIENT_BUFFER);
+    if (calling_module_path.empty())
+        return -1;
+
+    calling_module_path = (std::filesystem::path(calling_module_path).parent_path() / L"nethost.dll").wstring();
+
+    auto lib_nethost = reinterpret_cast<void*>(load_library(calling_module_path.c_str()));
+    if (!lib_nethost)
+        return -1;
+
+    auto get_hostfxr_path = reinterpret_cast<get_hostfxr_path_type>(
+        get_export(lib_nethost, "get_hostfxr_path"));
+    if (!get_hostfxr_path)
+        return -1;
+
     wchar_t buffer[MAX_PATH]{};
     size_t buffer_size = sizeof buffer / sizeof(wchar_t);
     if (int rc = get_hostfxr_path(buffer, &buffer_size, parameters); rc != 0)
         return rc;
 
     // Load hostfxr and get desired exports
-    auto lib = reinterpret_cast<void*>(load_library(buffer));
+    auto lib_hostfxr = reinterpret_cast<void*>(load_library(buffer));
+    if (!lib_hostfxr)
+        return -1;
+
     m_hostfxr_initialize_for_runtime_config_fptr = reinterpret_cast<hostfxr_initialize_for_runtime_config_fn>(
-        get_export(lib, "hostfxr_initialize_for_runtime_config"));
+        get_export(lib_hostfxr, "hostfxr_initialize_for_runtime_config"));
     m_hostfxr_get_runtime_delegate_fptr = reinterpret_cast<hostfxr_get_runtime_delegate_fn>(
-        get_export(lib, "hostfxr_get_runtime_delegate"));
+        get_export(lib_hostfxr, "hostfxr_get_runtime_delegate"));
     m_hostfxr_close_fptr = reinterpret_cast<hostfxr_close_fn>(
-        get_export(lib, "hostfxr_close"));
+        get_export(lib_hostfxr, "hostfxr_close"));
 
     return m_hostfxr_initialize_for_runtime_config_fptr
         && m_hostfxr_get_runtime_delegate_fptr

lib/CoreCLR/CoreCLR.h

@@ -5,8 +5,10 @@
 #include "nethost/nethost.h"
 
 class CoreCLR {
-    public:
-    explicit CoreCLR();
+    void* const m_calling_module;
+
+public:
+    explicit CoreCLR(void* calling_module);
     ~CoreCLR() = default;
 
     int load_hostfxr();
@@ -32,7 +34,7 @@ class CoreCLR {
         void* reserved,
         void** delegate) const;
 
-    private:
+private:
     /* HostFXR delegates. */
     hostfxr_initialize_for_runtime_config_fn m_hostfxr_initialize_for_runtime_config_fptr{};
     hostfxr_get_runtime_delegate_fn m_hostfxr_get_runtime_delegate_fptr{};

lib/CoreCLR/boot.cpp

@@ -26,6 +26,7 @@ void ConsoleTeardown()
 std::optional<CoreCLR> g_clr;
 
 int InitializeClrAndGetEntryPoint(
+    void* calling_module,
     std::wstring runtimeconfig_path,
     std::wstring module_path,
     std::wstring entrypoint_assembly_name,
@@ -33,7 +34,7 @@ int InitializeClrAndGetEntryPoint(
     std::wstring entrypoint_delegate_type_name,
     void** entrypoint_fn)
 {
-    g_clr = CoreCLR();
+    g_clr.emplace(calling_module);
 
     int result;
     SetEnvironmentVariable(L"DOTNET_MULTILEVEL_LOOKUP", L"0");

lib/CoreCLR/boot.h

@@ -2,6 +2,7 @@ void ConsoleSetup(const std::wstring console_name);
 void ConsoleTeardown();
 
 int InitializeClrAndGetEntryPoint(
+    void* calling_module,
     std::wstring runtimeconfig_path,
     std::wstring module_path,
     std::wstring entrypoint_assembly_name,

lib/CoreCLR/nethost/nethost.h

@@ -6,36 +6,6 @@
 
 #include <stddef.h>
 
-#ifdef _WIN32
-    #ifdef NETHOST_EXPORT
-        #define NETHOST_API __declspec(dllexport)
-    #else
-        // Consuming the nethost as a static library
-        // Shouldn't export attempt to dllimport.
-        #ifdef NETHOST_USE_AS_STATIC
-            #define NETHOST_API 
-        #else
-            #define NETHOST_API __declspec(dllimport)
-        #endif
-    #endif
-
-    #define NETHOST_CALLTYPE __stdcall
-    #ifdef _WCHAR_T_DEFINED
-        typedef wchar_t char_t;
-    #else
-        typedef unsigned short char_t;
-    #endif
-#else
-    #ifdef NETHOST_EXPORT
-        #define NETHOST_API __attribute__((__visibility__("default")))
-    #else
-        #define NETHOST_API
-    #endif
-
-    #define NETHOST_CALLTYPE
-    typedef char char_t;
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -87,10 +57,10 @@ struct get_hostfxr_parameters {
 //   The full search for the hostfxr library is done on every call. To minimize the need
 //   to call this function multiple times, pass a large buffer (e.g. PATH_MAX).
 //
-NETHOST_API int NETHOST_CALLTYPE get_hostfxr_path(
-    char_t * buffer,
-    size_t * buffer_size,
-    const struct get_hostfxr_parameters *parameters);
+using get_hostfxr_path_type = int(__stdcall *)(
+    char_t* buffer,
+    size_t* buffer_size,
+    const struct get_hostfxr_parameters* parameters);
 
 #ifdef __cplusplus
 } // extern "C"