5 files changed, 847 insertions, 0 deletions
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
new file mode 100644
index 0000000..64f85f7
--- /dev/null
+++ b/tests/CMakeLists.txt
@@ -0,0 +1,12 @@
+enable_testing()
+include_directories(../src)
+add_library(testdll SHARED testdll.c)
+set_target_properties(testdll PROPERTIES PREFIX "")
+add_library(testdll2 SHARED testdll2.c)
+set_target_properties(testdll2 PROPERTIES PREFIX "")
+target_link_libraries(testdll2 dl)
+add_library(testdll3 SHARED testdll3.c)
+set_target_properties(testdll3 PROPERTIES PREFIX "")
+add_executable(t_dlfcn test.c)
+target_link_libraries(t_dlfcn dl)
+add_test (NAME t_dlfcn COMMAND t_dlfcn)
diff --git a/tests/test.c b/tests/test.c
new file mode 100644
index 0000000..5d060d2
--- /dev/null
+++ b/tests/test.c
@@ -0,0 +1,687 @@
+/*
+ * dlfcn-win32
+ * Copyright (c) 2007-2009 Ramiro Polla
+ * Copyright (c) 2014      Tiancheng "Timothy" Gu
+ * Copyright (c) 2019      Pali Rohár <pali.rohar@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifdef _DEBUG
+#define _CRTDBG_MAP_ALLOC
+#include <stdlib.h>
+#include <crtdbg.h>
+#endif
+#include <stdio.h>
+#include <string.h>
+#include <windows.h>
+#include <wchar.h>
+#include <io.h>
+#include <fcntl.h>
+#include <direct.h>
+#include "dlfcn.h"
+/* If these dlclose's fails, we don't care as the handles are going to be
+   closed eventually when the program ends. */
+#define CLOSE_LIB    dlclose( library )
+#define CLOSE_GLOBAL dlclose( global  )
+#define RETURN_ERROR printf("From line %d\n", __LINE__); return 1
+#define RUNFUNC do { \
+                    ret = function (); \
+                    if( ret != 0) {    \
+                        CLOSE_LIB;     \
+                        CLOSE_GLOBAL;  \
+                        RETURN_ERROR;  \
+                    }                  \
+                } while( 0 )
+/* This is what this test does:
+ * - Open library with RTLD_GLOBAL
+ * - Get global object
+ * - Get symbol from library through library object <- works
+ * - Run function if it worked
+ * - Get nonexistent symbol from library through library object <- fails
+ * - Get symbol from library through global object  <- works
+ * - Run function if it worked
+ * - Get nonexistent symbol from library through global object <- fails
+ * - Close library
+ * - Open library with RTLD_LOCAL
+ * - Get symbol from library through library object <- works
+ * - Run function if it worked
+ * - Get nonexistent symbol from library through library object <- fails
+ * - Get local symbol from library through global object  <- fails
+ * - Get nonexistent local symbol from library through global object <- fails
+ * - Open library again (without closing it first) with RTLD_GLOBAL
+ * - Get symbol from library through global object  <- works
+ * - Get nonexistent symbol from library through global object <- fails
+ * - Close library
+ * - Close global object
+ *
+ * If one test fails, the program terminates itself.
+ */
+int main()
+{
+    void *global;
+    void *library2;
+    void *library;
+    char *error;
+    int (*function)( void );
+    int (*function2_from_library2)( void );
+    size_t (*fwrite_local) ( const void *, size_t, size_t, FILE * );
+    size_t (*fputs_default) ( const char *, FILE * );
+    int (*nonexistentfunction)( void );
+    int fd;
+    int ret;
+    HMODULE library3;
+    char toolongfile[32767];
+    DWORD code;
+    char nonlibraryfile[MAX_PATH];
+    char bytename[sizeof("testdll2.dll")+4];
+    WCHAR widename[sizeof("testdll2.dll")+1];
+    DWORD length;
+    HANDLE tempfile;
+    DWORD dummy;
+    UINT uMode;
+#ifdef _DEBUG
+    _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
+    _CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDOUT);
+    _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_FILE);
+    _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDOUT);
+    _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_FILE);
+    _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDOUT);
+#endif
+    length = GetTempPathA( sizeof( nonlibraryfile ) - sizeof( "temp.dll" ), nonlibraryfile );
+    if( length == 0 || length > sizeof( nonlibraryfile ) - sizeof( "temp.dll" ) )
+    {
+        printf( "ERROR\tGetTempPath failed\n" );
+        RETURN_ERROR;
+    }
+    memcpy( nonlibraryfile + length, "temp.dll", sizeof( "temp.dll" ) );
+    tempfile = CreateFileA( (LPCSTR) nonlibraryfile, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, 0, NULL );
+    if( tempfile == INVALID_HANDLE_VALUE )
+    {
+        printf( "ERROR\tCannot create temporary file %s: %lu\n", nonlibraryfile, (unsigned long)GetLastError( ) );
+        RETURN_ERROR;
+    }
+    WriteFile( tempfile, "test content", 12, &dummy, NULL );
+    CloseHandle( tempfile );
+    uMode = SetErrorMode( SEM_FAILCRITICALERRORS );
+    library3 = LoadLibraryA( nonlibraryfile );
+    code = GetLastError( );
+    SetErrorMode( uMode );
+    if( library3 )
+    {
+        printf( "ERROR\tNon-library file %s was opened via WINAPI\n", nonlibraryfile );
+        CloseHandle( library3 );
+        DeleteFileA( nonlibraryfile );
+        RETURN_ERROR;
+    }
+    else if( code != ERROR_BAD_EXE_FORMAT )
+    {
+        printf( "ERROR\tNon-library file %s was processed via WINAPI: %lu\n", nonlibraryfile, (unsigned long)code );
+        DeleteFileA( nonlibraryfile );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not open non-library file %s via WINAPI: %lu\n", nonlibraryfile, (unsigned long)code );
+    library = dlopen( nonlibraryfile, RTLD_GLOBAL );
+    if( library )
+    {
+        printf( "ERROR\tNon-library file %s was opened via dlopen\n", nonlibraryfile );
+        dlclose( library );
+        DeleteFileA( nonlibraryfile );
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlopen for non-library file\n" );
+        DeleteFileA( nonlibraryfile );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not open non-library file %s: %s\n", nonlibraryfile, error );
+    DeleteFileA( nonlibraryfile );
+    library = dlopen( "nonexistentfile.dll", RTLD_GLOBAL );
+    if( library )
+    {
+        printf( "ERROR\tNon-existent file nonexistentfile.dll was opened via dlopen\n" );
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlopen for non-existent file\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not open non-existent file nonexistentfile.dll: %s\n", error );
+    memset( toolongfile, 'X', sizeof( toolongfile ) - 5 );
+    memcpy( toolongfile + sizeof( toolongfile ) - 5, ".dll", 5 );
+    library = dlopen( toolongfile, RTLD_GLOBAL );
+    if( library )
+    {
+        printf( "ERROR\tFile with too long file name was opened via dlopen\n" );
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlopen for file with too long file name\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not open file with too long file name: %s\n", error );
+    uMode = SetErrorMode( SEM_FAILCRITICALERRORS );
+    library3 = LoadLibraryA( toolongfile );
+    code = GetLastError( );
+    SetErrorMode( uMode );
+    if( library3 )
+    {
+        printf( "ERROR\tFile with too long file name was opened via WINAPI\n" );
+        RETURN_ERROR;
+    }
+    else if( code != ERROR_FILENAME_EXCED_RANGE )
+    {
+        printf( "ERROR\tFile with too long file name was processed via WINAPI: %lu\n", (unsigned long)code );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not open file with too long file name via WINAPI: %lu\n", (unsigned long)code );
+    fd = _open( "testdll2.dll", _O_RDONLY | _O_BINARY );
+    if( fd < 0 )
+    {
+        if( _chdir( "Debug" ) == 0 )
+        {
+            fd = _open( "testdll2.dll", _O_RDONLY | _O_BINARY );
+            if( fd < 0 )
+                _chdir( ".." );
+        }
+    }
+    if( fd < 0 )
+    {
+        if( _chdir( "Release" ) == 0 )
+        {
+            fd = _open( "testdll2.dll", _O_RDONLY | _O_BINARY );
+            if( fd < 0 )
+                _chdir( ".." );
+        }
+    }
+    if( fd < 0 )
+    {
+        printf( "ERROR\tCould not open library2 file: %s\n", strerror( errno ) );
+        RETURN_ERROR;
+    }
+    _close( fd );
+    library2 = dlopen( "testdll2.dll", RTLD_GLOBAL );
+    if( !library2 )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not open library2 globally: %s\n", error ? error : "" );
+        RETURN_ERROR; 
+    }
+    else
+        printf( "SUCCESS\tOpened library2 globally: %p\n", library2 );
+    widename[0] = 0xE1; /* wide non-ASCII character mappable to most ANSI codepages */
+    wcscpy( widename+1, L"testdll2.dll" );
+    if( !CopyFileW( L"testdll2.dll", widename, FALSE ))
+    {
+        printf( "ERROR\tCould not copy file testdll2.dll: %lu\n", (unsigned long)GetLastError( ) );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCopied testdll2.dll to wide name %ls\n", widename );
+    ret = WideCharToMultiByte( CP_ACP, 0, widename, -1, bytename, sizeof( bytename ), NULL, NULL );
+    /* if we cannot convert widename to current codepage (used by _open() function), skip this test */
+    if( ret > 0 )
+    {
+        bytename[ret] = 0;
+        fd = _wopen( widename, _O_RDONLY | _O_BINARY );
+        if( fd < 0 )
+        {
+            printf( "ERROR\tCould not open copied wide library2 file %ls: %s\n", widename, strerror( errno ) );
+            DeleteFileW( widename );
+            RETURN_ERROR;
+        }
+        _close( fd );
+        fd = _open( bytename, _O_RDONLY | _O_BINARY );
+        if( fd < 0 )
+        {
+            printf( "ERROR\tCould not open copied wide library2 file %s: %s\n", bytename, strerror( errno ) );
+            DeleteFileW( widename );
+            RETURN_ERROR;
+        }
+        _close( fd );
+        dlclose( library2 );
+        library2 = dlopen( bytename, RTLD_GLOBAL );
+        if( !library2 )
+        {
+            error = dlerror( );
+            printf( "ERROR\tCould not open copied wide library2 file %s globally: %s\n", bytename, error ? error : "" );
+            DeleteFileW( widename );
+            RETURN_ERROR;
+        }
+        else
+            printf( "SUCCESS\tOpened copied wide library2 file %s globally: %p\n", bytename, library2 );
+        dlclose( library2 );
+        DeleteFileW( widename );
+        library2 = dlopen( "testdll2.dll", RTLD_GLOBAL );
+        if( !library2 )
+        {
+            error = dlerror( );
+            printf( "ERROR\tCould not open library2 globally: %s\n", error ? error : "" );
+            RETURN_ERROR;
+        }
+        else
+            printf( "SUCCESS\tOpened library2 globally: %p\n", library2 );
+    }
+    library = dlopen( "testdll.dll", RTLD_GLOBAL );
+    if( !library )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not open library globally: %s\n", error ? error : "" );
+        RETURN_ERROR; 
+    }
+    else
+        printf( "SUCCESS\tOpened library globally: %p\n", library );
+    global = dlopen( 0, RTLD_GLOBAL );
+    if( !global )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not open global handle: %s\n", error ? error : "" );
+        CLOSE_LIB;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot global handle: %p\n", global );
+    *(void **) (&fwrite_local) = dlsym( global, "fwrite" );
+    if (!fwrite_local)
+    {
+        error = dlerror();
+        printf("ERROR\tCould not get symbol from global handle: %s\n",
+            error ? error : "");
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from global handle: %p\n", *(void **) (&fwrite_local) );
+    {
+        const char *hello_world = "Hello world from local fwrite!\n";
+        fwrite_local( hello_world, sizeof( char ), strlen( hello_world ), stderr );
+        fflush( stderr );
+    }
+    *(void **) (&fputs_default) = dlsym( RTLD_DEFAULT, "fputs" );
+    if (!fputs_default)
+    {
+        error = dlerror();
+        printf("ERROR\tCould not get symbol from default handle: %s\n",
+            error ? error : "");
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from default handle: %p\n", *(void **) (&fputs_default) );
+    {
+        const char *hello_world_fputs = "Hello world from default fputs!\n";
+        fputs_default( hello_world_fputs, stderr );
+        fflush( stderr );
+    }
+    *(void **) (&function) = dlsym( library, "function" );
+    if( !function )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not get symbol from library handle: %s\n",
+                error ? error : "" );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from library handle: %p\n", *(void **) (&function) );
+    RUNFUNC;
+    *(void **) (&function2_from_library2) = dlsym( library2, "function2" );
+    if( !function2_from_library2 )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not get symbol from library2 handle: %s\n",
+                error ? error : "" );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from library2 handle: %p\n", *(void **) (&function2_from_library2) );
+    ret = function2_from_library2 ();
+    if( ret != 2 )
+    {
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    *(void **) (&nonexistentfunction) = dlsym( library, "nonexistentfunction" );
+    if( nonexistentfunction )
+    {
+        error = dlerror( );
+        printf( "ERROR\tGot nonexistent symbol from library handle: %p\n", *(void **) (&nonexistentfunction) );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlsym for nonexistent symbol\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not get nonexistent symbol from library handle: %s\n", error );
+    *(void **) (&function) = dlsym( global, "function" );
+    if( !function )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not get symbol from global handle: %s\n",
+                error ? error : "" );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from global handle: %p\n", *(void **) (&function) );
+    RUNFUNC;
+    *(void **) (&nonexistentfunction) = dlsym( global, "nonexistentfunction" );
+    if( nonexistentfunction )
+    {
+        error = dlerror( );
+        printf( "ERROR\tGot nonexistent symbol from global handle: %p\n", *(void **) (&nonexistentfunction) );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlsym for nonexistent symbol\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not get nonexistent symbol from global handle: %s\n", error );
+    ret = dlclose( library );
+    if( ret )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not close library: %s\n", error ? error : "" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tClosed library.\n" );
+    ret = dlclose( library2 );
+    if( ret )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not close library2: %s\n", error ? error : "" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tClosed library2.\n" );
+    library = dlopen( "testdll.dll", RTLD_LOCAL );
+    if( !library )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not open library locally: %s\n", error ? error : "" );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tOpened library locally: %p\n", library );
+    *(void **) (&function) = dlsym( library, "function" );
+    if( !function )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not get symbol from library handle: %s\n",
+                error ? error : "" );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from library handle: %p\n", *(void **) (&function) );
+    RUNFUNC;
+    *(void **) (&nonexistentfunction) = dlsym( library, "nonexistentfunction" );
+    if( nonexistentfunction )
+    {
+        error = dlerror( );
+        printf( "ERROR\tGot nonexistent symbol from library handle: %p\n", *(void **) (&nonexistentfunction) );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlsym for nonexistent symbol\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tCould not get nonexistent symbol from library handle: %s\n", error );
+    *(void **) (&function) = dlsym( global, "function" );
+    if( function )
+    {
+        error = dlerror( );
+        printf( "ERROR\tGot local symbol from global handle: %s @ %p\n",
+                error ? error : "", *(void **) (&function) );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tDid not get local symbol from global handle.\n" );
+    *(void **) (&nonexistentfunction) = dlsym( global, "nonexistentfunction" );
+    if( nonexistentfunction )
+    {
+        error = dlerror( );
+        printf( "ERROR\tGot nonexistent local symbol from global handle: %p\n", *(void **) (&nonexistentfunction) );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlsym for nonexistent symbol\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tDid not get nonexistent local symbol from global handle: %s\n", error );
+    library = dlopen( "testdll.dll", RTLD_GLOBAL );
+    if( !library )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not open library globally without closing it first: %s\n", error ? error : "" );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tOpened library globally without closing it first: %p\n", library );
+    *(void **) (&function) = dlsym( global, "function" );
+    if( !function )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not get symbol from global handle: %s\n",
+                error ? error : "" );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from global handle: %p\n", *(void **) (&function) );
+    RUNFUNC;
+    *(void **) (&nonexistentfunction) = dlsym( global, "nonexistentfunction" );
+    if( nonexistentfunction )
+    {
+        error = dlerror( );
+        printf( "ERROR\tGot nonexistent symbol from global handle: %p\n", *(void **) (&nonexistentfunction) );
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    error = dlerror( );
+    if( !error )
+    {
+        printf( "ERROR\tNo error from dlsym for nonexistent symbol\n" );
+        RETURN_ERROR;
+    }
+    else
+    {
+        printf( "SUCCESS\tCould not get nonexistent symbol from global handle: %s\n", error );
+                
+        /* Test that the second call to dlerror() returns null as in the specs 
+           See https://github.com/dlfcn-win32/dlfcn-win32/issues/34 */
+        error = dlerror( );
+        if( error == NULL )
+        {
+            printf( "SUCCESS\tSecond consecutive call to dlerror returned NULL\n");
+        }
+        else 
+        {
+            printf( "ERROR\tSecond consecutive call to dlerror returned a non-NULL pointer: %p\n", error );
+            CLOSE_LIB;
+            CLOSE_GLOBAL;
+            RETURN_ERROR;
+        }
+    }
+    *(void **) (&function) = dlsym( global, "fwrite" );
+    if (!function)
+    {
+        error = dlerror();
+        printf("ERROR\tCould not get symbol from global handle: %s\n",
+            error ? error : "");
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from global handle: %p\n", *(void **) (&function) );
+    
+    uMode = SetErrorMode( SEM_FAILCRITICALERRORS );
+    library3 = LoadLibraryA("testdll3.dll");
+    SetErrorMode( uMode );
+    if (!library3)
+    {
+        printf( "ERROR\tCould not open library3 via WINAPI\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tOpened library3 via WINAPI: %p\n", (void *)library3 );
+    ret = dlclose( library );
+    if( ret )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not close library: %s\n", error ? error : "" );
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tClosed library.\n" );
+    *(void **) (&function) = dlsym( global, "function3" );
+    if (!function)
+    {
+        error = dlerror();
+        printf("ERROR\tCould not get symbol from global handle: %s\n",
+            error ? error : "");
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tGot symbol from global handle: %p\n", *(void **) (&function) );
+    RUNFUNC;
+    ret = dlclose( global );
+    if( ret )
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not close global handle: %s\n", error ? error : "" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tClosed global handle.\n" );
+#ifdef _DEBUG
+    _CrtDumpMemoryLeaks();
+#endif
+    return 0;
+}
diff --git a/tests/testdll.c b/tests/testdll.c
new file mode 100644
index 0000000..5bb0f43
--- /dev/null
+++ b/tests/testdll.c
@@ -0,0 +1,47 @@
+/*
+ * dlfcn-win32
+ * Copyright (c) 2007 Ramiro Polla
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifdef _DEBUG
+#define _CRTDBG_MAP_ALLOC
+#include <stdlib.h>
+#include <crtdbg.h>
+#endif
+#include <stdio.h>
+#if defined(_WIN32)
+#define EXPORT __declspec(dllexport)
+#else
+#define EXPORT
+#endif
+EXPORT int function2( void )
+{
+    printf( "Hello, world! from original library\n" );
+    return 0;
+}
+EXPORT int function( void )
+{
+    printf( "Hello, world!\n" );
+    return 0;
+}
diff --git a/tests/testdll2.c b/tests/testdll2.c
new file mode 100644
index 0000000..1560738
--- /dev/null
+++ b/tests/testdll2.c
@@ -0,0 +1,59 @@
+/*
+ * dlfcn-win32
+ * Copyright (c) 2007 Ramiro Polla
+ * Copyright (c) 2019 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifdef _DEBUG
+#define _CRTDBG_MAP_ALLOC
+#include <stdlib.h>
+#include <crtdbg.h>
+#endif
+#include <stdio.h>
+#include "dlfcn.h"
+#if defined(_WIN32)
+#define EXPORT __declspec(dllexport)
+#else
+#define EXPORT
+#endif
+EXPORT int function2( void )
+{
+    char *error;
+    int (*function2_orig)(void);
+    printf( "Hello, world! from wrapper library\n" );
+    *(void **) (&function2_orig) = dlsym( RTLD_NEXT, "function2" );
+    if (!function2_orig)
+    {
+        error = dlerror( );
+        printf( "ERROR\tCould not get symbol from RTLD_NEXT handle: %s\n",
+                error ? error : "" );
+        return 1;
+    }
+    if (function2_orig() != 0)
+    {
+        printf( "ERROR\tOriginal function from RTLD_NEXT handle did not return correct value\n" );
+        return 1;
+    }
+    return 2;
+}
diff --git a/tests/testdll3.c b/tests/testdll3.c
new file mode 100644
index 0000000..b6f4f5b
--- /dev/null
+++ b/tests/testdll3.c
@@ -0,0 +1,42 @@
+/*
+ * dlfcn-win32
+ * Copyright (c) 2007 Ramiro Polla
+ * Copyright (c) 2019 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifdef _DEBUG
+#define _CRTDBG_MAP_ALLOC
+#include <stdlib.h>
+#include <crtdbg.h>
+#endif
+#include <stdio.h>
+#if defined(_WIN32)
+#define EXPORT __declspec(dllexport)
+#else
+#define EXPORT
+#endif
+EXPORT int function3( void )
+{
+    printf( "Hello, world!\n" );
+    return 0;
+}