fix: crash when nullptr is passed as argument in get_function or get_…

…variable when no dynamic lib is currently loaded
martin-olivier · Feb 7, 2022 · d1fb984 · d1fb984
1 parent 48f3a78
commit d1fb984
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Showing 3 changed files with 39 additions and 18 deletions.
diff --git a/README.md b/README.md
@@ -1,5 +1,5 @@
 # Dylib - Dynamic Library Loader for C++  
-[![Dylib](https://img.shields.io/badge/Dylib-v1.8.0-blue.svg)](https://github.com/martin-olivier/dylib/releases/tag/v1.8.0)
+[![Dylib](https://img.shields.io/badge/Dylib-v1.8.1-blue.svg)](https://github.com/martin-olivier/dylib/releases/tag/v1.8.1)
 [![MIT license](https://img.shields.io/badge/License-MIT-orange.svg)](https://github.com/martin-olivier/dylib/blob/main/LICENSE)
 [![CPP Version](https://img.shields.io/badge/C++-11_and_above-darkgreen.svg)](https://isocpp.org/)
 
@@ -10,7 +10,7 @@
 [![workflow](https://github.com/martin-olivier/dylib/actions/workflows/CI.yml/badge.svg)](https://github.com/martin-olivier/dylib/actions/workflows/CI.yml)
 [![codecov](https://codecov.io/gh/martin-olivier/dylib/branch/main/graph/badge.svg?token=4V6A9B7PII)](https://codecov.io/gh/martin-olivier/dylib)
 
-[![GitHub download](https://img.shields.io/github/downloads/martin-olivier/dylib/total?style=for-the-badge)](https://github.com/martin-olivier/dylib/releases/download/v1.8.0/dylib.hpp)
+[![GitHub download](https://img.shields.io/github/downloads/martin-olivier/dylib/total?style=for-the-badge)](https://github.com/martin-olivier/dylib/releases/download/v1.8.1/dylib.hpp)
 
 The goal of this C++ Library is to load dynamic libraries (.so, .dll, .dylib) and access its functions and global variables at runtime.
 
@@ -19,7 +19,7 @@ Works on `Linux`, `Windows`, `MacOS`
 
 # Installation
 
-Click [HERE](https://github.com/martin-olivier/dylib/releases/download/v1.8.0/dylib.hpp) to download the dylib header file  
+Click [HERE](https://github.com/martin-olivier/dylib/releases/download/v1.8.1/dylib.hpp) to download the dylib header file  
 `⭐ Don't forget to put a star if you like the project!`
 
 # Documentation

diff --git a/dylib.hpp b/dylib.hpp
@@ -2,7 +2,7 @@
  * \file dylib.hpp
  * \brief Cross-platform Dynamic Library Loader
  * \author Martin Olivier
- * \version 1.8.0
+ * \version 1.8.1
  * 
  * MIT License
  * Copyright (c) 2022 Martin Olivier
@@ -47,13 +47,13 @@ class dylib
     }
     static char *get_error_message() noexcept
     {
-        constexpr size_t bufSize = 512;
-        auto errorCode = GetLastError();
-        if (!errorCode)
+        constexpr size_t buf_size = 512;
+        auto error_code = GetLastError();
+        if (!error_code)
             return nullptr;
-        static char msg[bufSize];
+        static char msg[buf_size];
         auto lang = MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US);
-        const DWORD len = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, nullptr, errorCode, lang, msg, bufSize, nullptr);
+        const DWORD len = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, nullptr, error_code, lang, msg, buf_size, nullptr);
         if (len > 0)
             return msg;
         return nullptr;
@@ -149,9 +149,8 @@ class dylib
     dylib(const dylib&) = delete;
     dylib& operator=(const dylib&) = delete;
 
-    dylib(dylib &&other) noexcept
+    dylib(dylib &&other) noexcept : m_handle(other.m_handle)
     {
-        m_handle = other.m_handle;
         other.m_handle = nullptr;
     }
 
@@ -234,10 +233,10 @@ class dylib
     template<typename T>
     std::function<T> get_function(const char *name) const
     {
-        if (!m_handle)
-            throw handle_error(get_missing_handle_error(name));
         if (!name)
             throw symbol_error(get_symbol_error("(nullptr)"));
+        if (!m_handle)
+            throw handle_error(get_missing_handle_error(name));
         auto sym = get_symbol(name);
         if (!sym)
             throw symbol_error(get_symbol_error(name));
@@ -261,10 +260,10 @@ class dylib
     template<typename T>
     T &get_variable(const char *name) const
     {
-        if (!m_handle)
-            throw handle_error(get_missing_handle_error(name));
         if (!name)
             throw symbol_error(get_symbol_error("(nullptr)"));
+        if (!m_handle)
+            throw handle_error(get_missing_handle_error(name));
         auto sym = get_symbol(name);
         if (!sym)
             throw symbol_error(get_symbol_error(name));
@@ -287,10 +286,10 @@ class dylib
      */
     bool has_symbol(const char *symbol) const noexcept
     {
-        if (!m_handle)
-            return false;
         if (!symbol)
             return false;
+        if (!m_handle)
+            return false;
         return get_symbol(symbol) != nullptr;
     }
 

diff --git a/tests/tests.cpp b/tests/tests.cpp
@@ -64,6 +64,12 @@ TEST(ctor, bad_library)
     }
 }
 
+TEST(multiple_handles, basic_test)
+{
+    dylib libA("./dynamic_lib", dylib::extension);
+    dylib libB("./dynamic_lib", dylib::extension);
+}
+
 TEST(dtor, mutiple_open_close)
 {
     try {
@@ -166,7 +172,7 @@ TEST(bad_arguments, null_pointer)
     }
     try {
         dylib lib(std::string("./dynamic_lib") + std::string(dylib::extension));
-        auto nothing = lib.get_function<void()>(nullptr);
+        lib.get_function<void()>(nullptr);
         EXPECT_EQ(true, false);
     }
     catch (const dylib::symbol_error &) {
@@ -180,6 +186,22 @@ TEST(bad_arguments, null_pointer)
     catch (const dylib::symbol_error &) {
         EXPECT_EQ(true, true);
     }
+    try {
+        dylib lib;
+        lib.get_function<void()>(nullptr);
+        EXPECT_EQ(true, false);
+    }
+    catch (const dylib::symbol_error &) {
+        EXPECT_EQ(true, true);
+    }
+    try {
+        dylib lib;
+        lib.get_variable<void *>(nullptr);
+        EXPECT_EQ(true, false);
+    }
+    catch (const dylib::symbol_error &) {
+        EXPECT_EQ(true, true);
+    }
 }
 
 TEST(bad_arguments, handle_and_ext)