Undefined references when compiling SDL project with MingW (NOT WinMain error) - c

I've been going a bit crazy trying to figure out the issue here. My project builds fine on Fedora with it's native gcc and pkg-config flags but when cross-compiling or using MingW on Windows it gives me undefined references. The oddest thing was, I remember getting it to compile once or twice on Windows but I have no idea how. As far as I know, all the libraries are accessible, so I can't figure out what's wrong.
With this input:
mingw32-gcc -std=c99 -g -LC:/MinGW/lib -mwindows -lSDL -lSDLmain -lfreetype -lmingw32 -lglu32 -lopengl32 -o bin/gltris.exe gltris.o graphics.o input.o game.o block.o timer.o text.o
I get this output: (sorry for the weird formatting)
C:/MinGW/lib/libmingw32.a(main.o):main.c:(.text.startup+0xa7): undefined reference to `WinMain#16'
gltris.o: In function `gltris_init':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/gltris.c:24: undefined reference to `SDL_Init'
gltris.o: In function `SDL_main':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/gltris.c:110: undefined reference to `SDL_Quit'
graphics.o: In function `graphics_init':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:31: undefined reference to `SDL_SetVideoMode'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:34: undefined reference to `glClearColor#16'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:35: undefined reference to `glClear#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:36: undefined reference to `glViewport#16'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:38: undefined reference to `glMatrixMode#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:39: undefined reference to `glLoadIdentity#0'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:40: undefined reference to `glDisable#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:41: undefined reference to `glBlendFunc#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:42: undefined reference to `glPixelStorei#8'
graphics.o: In function `graphics_begin_frame':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:50: undefined reference to `glMatrixMode#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:51: undefined reference to `glLoadIdentity#0'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:52: undefined reference to `glClear#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:54: undefined reference to `gluOrtho2D#32'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:56: undefined reference to `glMatrixMode#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:57: undefined reference to `glLoadIdentity#0'
graphics.o: In function `graphics_end_frame':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:62: undefined reference to `SDL_GL_SwapBuffers'
graphics.o: In function `graphics_render_block':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:68: undefined reference to `glPushMatrix#0'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:70: undefined reference to `glTranslatef#12'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:71: undefined reference to `glScalef#12'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:74: undefined reference to `glColor4ub#16'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:76: undefined reference to `glColor3ubv#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:78: undefined reference to `glEnable#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:81: undefined reference to `glBegin#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:82: undefined reference to `glVertex2i#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:83: undefined reference to `glVertex2i#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:84: undefined reference to `glVertex2i#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:85: undefined reference to `glVertex2i#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:86: undefined reference to `glEnd#0'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:88: undefined reference to `glDisable#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:90: undefined reference to `glPopMatrix#0'
graphics.o: In function `render_textured_quad':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:165: undefined reference to `glPushMatrix#0'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:167: undefined reference to `glEnable#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:168: undefined reference to `glEnable#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:169: undefined reference to `glBindTexture#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:171: undefined reference to `glTranslatef#12'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:173: undefined reference to `glBegin#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:175: undefined reference to `glTexCoord2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:176: undefined reference to `glVertex2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:178: undefined reference to `glTexCoord2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:179: undefined reference to `glVertex2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:181: undefined reference to `glTexCoord2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:182: undefined reference to `glVertex2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:184: undefined reference to `glTexCoord2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:185: undefined reference to `glVertex2f#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:187: undefined reference to `glEnd#0'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:189: undefined reference to `glDisable#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:190: undefined reference to `glDisable#4'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:192: undefined reference to `glPopMatrix#0'
graphics.o: In function `surface_to_texture':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:212: undefined reference to `glGenTextures#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:213: undefined reference to `glBindTexture#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:214: undefined reference to `glTexParameteri#12'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:215: undefined reference to `glTexParameteri#12'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:216: undefined reference to `glTexImage2D#36'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/graphics.c:221: undefined reference to `SDL_FreeSurface'
input.o: In function `handle_input':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/input.c:13: undefined reference to `SDL_PollEvent'
timer.o: In function `add_timer':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/timer.c:20: undefined reference to `SDL_GetTicks'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/timer.c:36: undefined reference to `SDL_GetTicks'
timer.o: In function `do_timers':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/timer.c:65: undefined reference to `SDL_GetTicks'
timer.o: In function `pause_timer':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/timer.c:84: undefined reference to `SDL_GetTicks'
timer.o: In function `resume_timer':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/timer.c:90: undefined reference to `SDL_GetTicks'
timer.o:C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/timer.c:98: more undefined references to `SDL_GetTicks' follow
text.o: In function `text_init':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:24: undefined reference to `_imp__FT_Init_FreeType'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:28: undefined reference to `_imp__FT_New_Face'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:32: undefined reference to `_imp__FT_Set_Char_Size'
text.o: In function `text_gen_texture':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:70: undefined reference to `glGenTextures#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:71: undefined reference to `glBindTexture#8'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:72: undefined reference to `glTexParameteri#12'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:73: undefined reference to `glTexParameteri#12'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:77: undefined reference to `glTexImage2D#36'
text.o: In function `text_print':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:92: undefined reference to `_imp__FT_Set_Char_Size'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:97: undefined reference to `_imp__FT_Load_Char'
text.o: In function `get_text_size':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:115: undefined reference to `_imp__FT_Set_Char_Size'
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:119: undefined reference to `_imp__FT_Load_Char'
text.o: In function `print_game_info':
C:\MinGW\msys\1.0\home\Max\gltris-unstable/src/text.c:138: undefined reference to `glColor3f#12'
collect2.exe: error: ld returned 1 exit status
EDIT:I got it to build by compiling and linking in one go, with the linker flags "-lmingw32 -lopengl32 -lSDLmain -lSDL -lfreetype -mwindows"

It seems like your compiler cannot find libSDL.a and other library files. Check if libSDL.a is present in C:/MinGW/lib. You will need a libSDL.a that is specifically made for mingw.
Also, try compiling a simple "Hello World" SDL program. That will make it easier to find what the error is.

Related

Compiling pyx files

I've just started to learn cython and this is the first time that I'm trying to compile .pyx files.
I tried to run in my cmd:
Cython fib.pyx
which gave me my fib.c file.
then I run:
gcc -c fib.c -I/Python27/include
which gave me my fib.o file, but when I tried to
gcc -shared fib.o -o fib.so
it gave me this exception:
fib.o:fib.c:(.text+0x72): undefined reference to `_imp__PyObject_GetAttr'
fib.o:fib.c:(.text+0xdb): undefined reference to `_imp__PyErr_Occurred'
fib.o:fib.c:(.text+0x26c): undefined reference to `_imp__PyString_FromString'
fib.o:fib.c:(.text+0x2ae): undefined reference to `_imp__PyNumber_Add'
fib.o:fib.c:(.text+0x31c): undefined reference to `_imp__PyMethod_Type'
fib.o:fib.c:(.text+0x418): undefined reference to `_imp__PyTuple_New'
fib.o:fib.c:(.text+0x53b): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x543): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x54d): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x79d): undefined reference to `_imp__PyNumber_Add'
fib.o:fib.c:(.text+0x874): undefined reference to `_imp__PyList_Type'
fib.o:fib.c:(.text+0x88b): undefined reference to `_imp__PyTuple_Type'
fib.o:fib.c:(.text+0x8c4): undefined reference to `_imp__PyObject_GetIter'
fib.o:fib.c:(.text+0x972): undefined reference to `_imp__PyList_Type'
fib.o:fib.c:(.text+0xa0b): undefined reference to `_imp__PyErr_Occurred'
fib.o:fib.c:(.text+0xa1b): undefined reference to `_imp__PyExc_StopIteration'
fib.o:fib.c:(.text+0xa2f): undefined reference to `_imp__PyExc_StopIteration'
fib.o:fib.c:(.text+0xa40): undefined reference to `_imp__PyErr_GivenExceptionMatches'
fib.o:fib.c:(.text+0xa53): undefined reference to `_imp__PyErr_Clear'
fib.o:fib.c:(.text+0xac3): undefined reference to `_imp__PyTuple_New'
fib.o:fib.c:(.text+0xcec): undefined reference to `_imp__PyString_FromString'
fib.o:fib.c:(.text+0xd2e): undefined reference to `_imp__PyNumber_Add'
fib.o:fib.c:(.text+0xd96): undefined reference to `_imp__PyTuple_New'
fib.o:fib.c:(.text+0xe9e): undefined reference to `_imp__PyString_FromString'
fib.o:fib.c:(.text+0xee0): undefined reference to `_imp__PyNumber_Add'
fib.o:fib.c:(.text+0xf48): undefined reference to `_imp__PyTuple_New'
fib.o:fib.c:(.text+0x107c): undefined reference to `_imp__PyMethod_Type'
fib.o:fib.c:(.text+0x11d9): undefined reference to `_imp__PyList_Type'
fib.o:fib.c:(.text+0x11f0): undefined reference to `_imp__PyTuple_Type'
fib.o:fib.c:(.text+0x1229): undefined reference to `_imp__PyObject_GetIter'
fib.o:fib.c:(.text+0x12d7): undefined reference to `_imp__PyList_Type'
fib.o:fib.c:(.text+0x1370): undefined reference to `_imp__PyErr_Occurred'
fib.o:fib.c:(.text+0x1380): undefined reference to `_imp__PyExc_StopIteration'
fib.o:fib.c:(.text+0x1394): undefined reference to `_imp__PyExc_StopIteration'
fib.o:fib.c:(.text+0x13a5): undefined reference to `_imp__PyErr_GivenExceptionMatches'
fib.o:fib.c:(.text+0x13b8): undefined reference to `_imp__PyErr_Clear'
fib.o:fib.c:(.text+0x1472): undefined reference to `_imp__PyMethod_Type'
fib.o:fib.c:(.text+0x153f): undefined reference to `_imp__PyTuple_New'
fib.o:fib.c:(.text+0x183e): undefined reference to `_imp__PyMethod_Type'
fib.o:fib.c:(.text+0x19c0): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x19c8): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x19d2): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x1c16): undefined reference to `_imp__PyObject_GC_Track'
fib.o:fib.c:(.text+0x1c67): undefined reference to `_imp__PyObject_GC_UnTrack'
fib.o:fib.c:(.text+0x1d5b): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x1d63): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x1d6d): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x1e91): undefined reference to `_imp__PyCode_New'
fib.o:fib.c:(.text+0x1ee1): undefined reference to `_imp__PyTuple_Pack'
fib.o:fib.c:(.text+0x1f31): undefined reference to `_imp__PyTuple_Pack'
fib.o:fib.c:(.text+0x1fd2): undefined reference to `_imp__PyTuple_Pack'
fib.o:fib.c:(.text+0x20a4): undefined reference to `_imp__PyCode_New'
fib.o:fib.c:(.text+0x2185): undefined reference to `_imp__PyTuple_New'
fib.o:fib.c:(.text+0x21cc): undefined reference to `_imp__PyString_FromStringAndSize'
fib.o:fib.c:(.text+0x224f): undefined reference to `_imp__Py_InitModule4'
fib.o:fib.c:(.text+0x22a4): undefined reference to `_imp__PyModule_GetDict'
fib.o:fib.c:(.text+0x22ef): undefined reference to `_imp__PyImport_AddModule'
fib.o:fib.c:(.text+0x2341): undefined reference to `_imp__PyObject_SetAttrString'
fib.o:fib.c:(.text+0x23ae): undefined reference to `_imp__PyObject_SetAttrString'
fib.o:fib.c:(.text+0x2423): undefined reference to `_imp__PyType_Ready'
fib.o:fib.c:(.text+0x24bf): undefined reference to `_imp__PyDict_SetItem'
fib.o:fib.c:(.text+0x252b): undefined reference to `_imp__PyCFunction_NewEx'
fib.o:fib.c:(.text+0x2577): undefined reference to `_imp__PyDict_SetItem'
fib.o:fib.c:(.text+0x25cb): undefined reference to `_imp__PyDict_New'
fib.o:fib.c:(.text+0x2614): undefined reference to `_imp__PyDict_SetItem'
fib.o:fib.c:(.text+0x26fe): undefined reference to `_imp__PyErr_Occurred'
fib.o:fib.c:(.text+0x2709): undefined reference to `_imp__PyExc_ImportError'
fib.o:fib.c:(.text+0x271b): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x2756): undefined reference to `_imp__PyExc_NameError'
fib.o:fib.c:(.text+0x276c): undefined reference to `_imp__PyErr_Format'
fib.o:fib.c:(.text+0x278d): undefined reference to `_imp__PyDict_GetItem'
fib.o:fib.c:(.text+0x27fb): undefined reference to `_imp__PyObject_Call'
fib.o:fib.c:(.text+0x2807): undefined reference to `_imp___PyThreadState_Current'
fib.o:fib.c:(.text+0x281a): undefined reference to `_imp___Py_CheckRecursionLimit'
fib.o:fib.c:(.text+0x2834): undefined reference to `_imp___Py_CheckRecursiveCall'
fib.o:fib.c:(.text+0x286a): undefined reference to `_imp___PyThreadState_Current'
fib.o:fib.c:(.text+0x2888): undefined reference to `_imp__PyErr_Occurred'
fib.o:fib.c:(.text+0x289b): undefined reference to `_imp__PyExc_SystemError'
fib.o:fib.c:(.text+0x28ad): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x28d4): undefined reference to `_imp___PyThreadState_Current'
fib.o:fib.c:(.text+0x28e7): undefined reference to `_imp___Py_CheckRecursionLimit'
fib.o:fib.c:(.text+0x2901): undefined reference to `_imp___Py_CheckRecursiveCall'
fib.o:fib.c:(.text+0x2930): undefined reference to `_imp___PyThreadState_Current'
fib.o:fib.c:(.text+0x294e): undefined reference to `_imp__PyErr_Occurred'
fib.o:fib.c:(.text+0x2961): undefined reference to `_imp__PyExc_SystemError'
fib.o:fib.c:(.text+0x2973): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x298c): undefined reference to `_imp__PyTuple_New'
fib.o:fib.c:(.text+0x2a16): undefined reference to `_imp__PyCFunction_Type'
fib.o:fib.c:(.text+0x2a51): undefined reference to `_imp__PyType_IsSubtype'
fib.o:fib.c:(.text+0x2ac8): undefined reference to `_imp__PyImport_AddModule'
fib.o:fib.c:(.text+0x2aff): undefined reference to `_imp__PyObject_GetAttrString'
fib.o:fib.c:(.text+0x2b22): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x2b38): undefined reference to `_imp__PyErr_Format'
fib.o:fib.c:(.text+0x2b5e): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x2b74): undefined reference to `_imp__PyErr_Format'
fib.o:fib.c:(.text+0x2b80): undefined reference to `_imp__PyExc_AttributeError'
fib.o:fib.c:(.text+0x2b8a): undefined reference to `_imp__PyErr_ExceptionMatches'
fib.o:fib.c:(.text+0x2b97): undefined reference to `_imp__PyErr_Clear'
fib.o:fib.c:(.text+0x2ba4): undefined reference to `_imp__PyType_Ready'
fib.o:fib.c:(.text+0x2bc8): undefined reference to `_imp__PyObject_SetAttrString'
fib.o:fib.c:(.text+0x2c7d): undefined reference to `_imp__PyString_FromString'
fib.o:fib.c:(.text+0x2ca5): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x2caf): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x2cb6): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x2ce7): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x2d5c): undefined reference to `_imp__PyString_InternFromString'
fib.o:fib.c:(.text+0x2dc7): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x2dd9): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x2e80): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x2e92): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x2f08): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x2f3a): undefined reference to `_imp__PyDict_New'
fib.o:fib.c:(.text+0x2f8b): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x2f9d): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x2fc8): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x2fda): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x3056): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x3060): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x3067): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x3086): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x313d): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x3147): more undefined references to `_imp___Py_NoneStruct' follow
fib.o:fib.c:(.text+0x3163): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x3175): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x321e): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x3244): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x324e): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x326a): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x327c): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x3325): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x334b): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x3370): undefined reference to `_imp__PyExc_TypeError'
fib.o:fib.c:(.text+0x3382): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x3406): undefined reference to `_imp__PyDict_New'
fib.o:fib.c:(.text+0x3451): undefined reference to `_imp__PyString_FromString'
fib.o:fib.c:(.text+0x3466): undefined reference to `_imp___PyObject_GC_New'
fib.o:fib.c:(.text+0x358f): undefined reference to `_imp__PyObject_GC_Track'
fib.o:fib.c:(.text+0x3969): undefined reference to `_imp__PyMem_Free'
fib.o:fib.c:(.text+0x398d): undefined reference to `_imp__PyObject_GC_UnTrack'
fib.o:fib.c:(.text+0x39a4): undefined reference to `_imp__PyObject_ClearWeakRefs'
fib.o:fib.c:(.text+0x39bc): undefined reference to `_imp__PyObject_GC_Del'
fib.o:fib.c:(.text+0x3cab): undefined reference to `_imp__PyMethod_New'
fib.o:fib.c:(.text+0x3cb4): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x3cd9): undefined reference to `_imp__PyMethod_New'
fib.o:fib.c:(.text+0x3cf1): undefined reference to `_imp__PyString_AsString'
fib.o:fib.c:(.text+0x3d0c): undefined reference to `_imp__PyString_FromFormat'
fib.o:fib.c:(.text+0x3d2f): undefined reference to `_imp__PyCFunction_Call'
fib.o:fib.c:(.text+0x3d3e): undefined reference to `_imp__PyCFunction_Call'
fib.o:fib.c:(.text+0x3d7c): undefined reference to `_imp__PyCFunction_Type'
fib.o:fib.c:(.text+0x3db7): undefined reference to `_imp__PyType_IsSubtype'
fib.o:fib.c:(.text+0x3e81): undefined reference to `_imp__PyList_New'
fib.o:fib.c:(.text+0x3ea4): undefined reference to `_imp__PyModule_GetDict'
fib.o:fib.c:(.text+0x3eb9): undefined reference to `_imp__PyDict_New'
fib.o:fib.c:(.text+0x3eda): undefined reference to `_imp__PyInt_FromLong'
fib.o:fib.c:(.text+0x3f1d): undefined reference to `_imp__PyObject_CallFunctionObjArgs'
fib.o:fib.c:(.text+0x4182): undefined reference to `_imp__PyMem_Malloc'
fib.o:fib.c:(.text+0x42b0): undefined reference to `_imp__PyMem_Realloc'
fib.o:fib.c:(.text+0x438a): undefined reference to `_imp__PyString_FromString'
fib.o:fib.c:(.text+0x43c3): undefined reference to `_imp__PyString_FromFormat'
fib.o:fib.c:(.text+0x43d5): undefined reference to `_imp__PyString_FromString'
fib.o:fib.c:(.text+0x4469): undefined reference to `_imp__PyCode_New'
fib.o:fib.c:(.text+0x45ae): undefined reference to `_imp___PyThreadState_Current'
fib.o:fib.c:(.text+0x45cb): undefined reference to `_imp__PyFrame_New'
fib.o:fib.c:(.text+0x45ec): undefined reference to `_imp__PyTraceBack_Here'
fib.o:fib.c:(.text+0x465c): undefined reference to `_imp__PySys_GetObject'
fib.o:fib.c:(.text+0x466c): undefined reference to `_imp__PyExc_RuntimeError'
fib.o:fib.c:(.text+0x467e): undefined reference to `_imp__PyErr_SetString'
fib.o:fib.c:(.text+0x46d5): undefined reference to `_imp__PyFile_SoftSpace'
fib.o:fib.c:(.text+0x46ee): undefined reference to `_imp__PyFile_WriteString'
fib.o:fib.c:(.text+0x4720): undefined reference to `_imp__PyFile_WriteObject'
fib.o:fib.c:(.text+0x4748): undefined reference to `_imp__PyString_AsString'
fib.o:fib.c:(.text+0x4758): undefined reference to `_imp__PyString_Size'
fib.o:fib.c:(.text+0x4798): undefined reference to `_imp__PyFile_SoftSpace'
fib.o:fib.c:(.text+0x47cc): undefined reference to `_imp__PyFile_WriteString'
fib.o:fib.c:(.text+0x47e7): undefined reference to `_imp__PyFile_SoftSpace'
fib.o:fib.c:(.text+0x4889): undefined reference to `_imp__PyFile_SoftSpace'
fib.o:fib.c:(.text+0x48a2): undefined reference to `_imp__PyFile_WriteString'
fib.o:fib.c:(.text+0x48c4): undefined reference to `_imp__PyFile_WriteObject'
fib.o:fib.c:(.text+0x48df): undefined reference to `_imp__PyFile_WriteString'
fib.o:fib.c:(.text+0x4977): undefined reference to `_imp__PyOS_snprintf'
fib.o:fib.c:(.text+0x497e): undefined reference to `_imp__Py_GetVersion'
fib.o:fib.c:(.text+0x499f): undefined reference to `_imp__PyOS_snprintf'
fib.o:fib.c:(.text+0x49ed): undefined reference to `_imp__PyOS_snprintf'
fib.o:fib.c:(.text+0x4a0d): undefined reference to `_imp__PyErr_WarnEx'
fib.o:fib.c:(.text+0x4a57): undefined reference to `_imp__PyUnicodeUCS2_DecodeUTF8'
fib.o:fib.c:(.text+0x4a7b): undefined reference to `_imp__PyString_InternFromString'
fib.o:fib.c:(.text+0x4aa1): undefined reference to `_imp__PyString_FromStringAndSize'
fib.o:fib.c:(.text+0x4afe): undefined reference to `_imp__PyByteArray_Type'
fib.o:fib.c:(.text+0x4b0e): undefined reference to `_imp__PyByteArray_Type'
fib.o:fib.c:(.text+0x4b1a): undefined reference to `_imp__PyType_IsSubtype'
fib.o:fib.c:(.text+0x4b2f): undefined reference to `_imp__PyByteArray_Type'
fib.o:fib.c:(.text+0x4b3f): undefined reference to `_imp__PyByteArray_Type'
fib.o:fib.c:(.text+0x4b4b): undefined reference to `_imp__PyType_IsSubtype'
fib.o:fib.c:(.text+0x4b83): undefined reference to `_imp__PyByteArray_Type'
fib.o:fib.c:(.text+0x4b93): undefined reference to `_imp__PyByteArray_Type'
fib.o:fib.c:(.text+0x4b9f): undefined reference to `_imp__PyType_IsSubtype'
fib.o:fib.c:(.text+0x4bd8): undefined reference to `_imp___PyByteArray_empty_string'
fib.o:fib.c:(.text+0x4bf3): undefined reference to `_imp__PyString_AsStringAndSize'
fib.o:fib.c:(.text+0x4c1c): undefined reference to `_imp___Py_TrueStruct'
fib.o:fib.c:(.text+0x4c2d): undefined reference to `_imp___Py_ZeroStruct'
fib.o:fib.c:(.text+0x4c40): undefined reference to `_imp___Py_NoneStruct'
fib.o:fib.c:(.text+0x4c5f): undefined reference to `_imp__PyObject_IsTrue'
collect2.exe: error: ld returned 1 exit status
I'll be grateful for any help.
I always compile my cython with one line of gcc:
gcc -shared -Wall -O3 -I Python27/include -L Python27/libs -o fib.so fib.c -l python27
You see, including the header files (-I) for python isn't enough. You also have to include the location of python's libraries (-L), and then the name of the file to use as that library (-l).
Happy Cythonizing!
There is another solution that might come in handy with bigger projects. Instead of writing yourself the gcc call in the command line you can create a configuration file in python that cython will use to autogenerate C or C++ code and call the gcc compiler with the appropriate flags.
Simply create a file setup.py (or a filename of your preference). Then fill it with:
from distutils.core import setup
from distutils.extension import Extension
from Cython.Build import cythonize
ext = Extension("fib",
sources=["fib.pyx"],
language="c++",
include_dirs=[],
libraries=[],
extra_link_args=[])
setup(ext_modules = cythonize([ext]))
Then in the terminal python setup.py build_ext --inplace.
This will generate a fib.cpp file and compile it to the shared object file fib.so as well as an object file fib.o (this last in a folder called build).
After that, you can already import fib in your *.py files.

How to fix linker errors for libudev on Ubuntu 15

I've installed libudev-dev, I can see the file /usr/lib/x86_64-linux-gnu/libudev.so but when I run gcc -Wall -ludev -o test test.c I get following error..
opensourcegeek#box:~/project/udev_device_discovery$ gcc -Wall -ludev -o test test.c
/tmp/ccg6Ydod.o: In function `main':
test.c:(.text+0xa): undefined reference to `udev_new'
test.c:(.text+0x35): undefined reference to `udev_enumerate_new'
test.c:(.text+0x4a): undefined reference to `udev_enumerate_add_match_subsystem'
test.c:(.text+0x60): undefined reference to `udev_enumerate_add_match_property'
test.c:(.text+0x76): undefined reference to `udev_enumerate_add_match_property'
test.c:(.text+0x82): undefined reference to `udev_enumerate_scan_devices'
test.c:(.text+0x8e): undefined reference to `udev_enumerate_get_list_entry'
test.c:(.text+0xab): undefined reference to `udev_list_entry_get_name'
test.c:(.text+0xc2): undefined reference to `udev_device_new_from_syspath'
test.c:(.text+0xd2): undefined reference to `udev_device_get_parent'
test.c:(.text+0xe2): undefined reference to `udev_device_get_devnode'
test.c:(.text+0x105): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x119): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x13f): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x153): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x179): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x197): undefined reference to `udev_device_unref'
test.c:(.text+0x1a3): undefined reference to `udev_list_entry_get_next'
test.c:(.text+0x1be): undefined reference to `udev_enumerate_unref'
test.c:(.text+0x1ca): undefined reference to `udev_unref'
test.c:(.text+0x1cf): undefined reference to `udev_new'
test.c:(.text+0x1fa): undefined reference to `udev_enumerate_new'
test.c:(.text+0x20f): undefined reference to `udev_enumerate_add_match_subsystem'
test.c:(.text+0x225): undefined reference to `udev_enumerate_add_match_property'
test.c:(.text+0x23b): undefined reference to `udev_enumerate_add_match_property'
test.c:(.text+0x247): undefined reference to `udev_enumerate_scan_devices'
test.c:(.text+0x253): undefined reference to `udev_enumerate_get_list_entry'
test.c:(.text+0x270): undefined reference to `udev_list_entry_get_name'
test.c:(.text+0x287): undefined reference to `udev_device_new_from_syspath'
test.c:(.text+0x297): undefined reference to `udev_device_get_devnode'
test.c:(.text+0x2ba): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x2ce): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x2f4): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x308): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x32e): undefined reference to `udev_device_get_sysattr_value'
test.c:(.text+0x34c): undefined reference to `udev_device_unref'
test.c:(.text+0x358): undefined reference to `udev_list_entry_get_next'
test.c:(.text+0x373): undefined reference to `udev_enumerate_unref'
test.c:(.text+0x37f): undefined reference to `udev_unref'
collect2: error: ld returned 1 exit status
I don't usually run ubuntu, but same code works on my fedora(slightly older version of libudev) and also a pi which runs wheezy (older version of libudev).
The order is important, put the library name at the end of the compilation / linking line:
$ gcc -Wall -o test test.c -ludev
The error you see is a linker error, not because of any installation issues.. Move -ludev to the end of the command line option:
gcc -Wall -o test test.c -ludev

"undefined reference" when trying to use lp_solve in C/C++ on Linux

I'm new to linear programming and C. I am trying to use the lp_solve library to solve a linear equation. The problem is I can't get the demo code to work.
As described in the documentation, I downloaded lp_solve_5.5_dev.gz to my Linux machine. I extracted the files into the same folder as my code and tried to compile:
~/Desktop/Code/CA$ cc -o demo demo.c
/tmp/ccpeN8ZV.o: In function `demo':
demo.c:(.text+0x31): undefined reference to `make_lp'
demo.c:(.text+0x62): undefined reference to `set_col_name'
demo.c:(.text+0x7d): undefined reference to `set_col_name'
demo.c:(.text+0xcf): undefined reference to `set_add_rowmode'
demo.c:(.text+0x150): undefined reference to `add_constraintex'
demo.c:(.text+0x1e6): undefined reference to `add_constraintex'
demo.c:(.text+0x274): undefined reference to `add_constraintex'
demo.c:(.text+0x29c): undefined reference to `set_add_rowmode'
demo.c:(.text+0x30b): undefined reference to `set_obj_fnex'
demo.c:(.text+0x327): undefined reference to `set_maxim'
demo.c:(.text+0x33b): undefined reference to `write_LP'
demo.c:(.text+0x34e): undefined reference to `set_verbose'
demo.c:(.text+0x359): undefined reference to `solve'
demo.c:(.text+0x383): undefined reference to `get_objective'
demo.c:(.text+0x3a6): undefined reference to `get_variables'
demo.c:(.text+0x3d2): undefined reference to `get_col_name'
demo.c:(.text+0x429): undefined reference to `delete_lp'
collect2: ld returned 1 exit status
When I add liblpsolve55.a to the command I get the following errors:
~/Desktop/Code/CA$ cc -o demo demo.c liblpsolve55.a
liblpsolve55.a(lp_lib.o): In function `scaled_floor':
lp_lib.c:(.text+0x6923): undefined reference to `floor'
liblpsolve55.a(lp_lib.o): In function `scaled_ceil':
lp_lib.c:(.text+0x6f03): undefined reference to `ceil'
liblpsolve55.a(lp_lib.o): In function `set_XLI':
lp_lib.c:(.text+0x7aa2): undefined reference to `dlclose'
lp_lib.c:(.text+0x7bb3): undefined reference to `dlopen'
lp_lib.c:(.text+0x7bd1): undefined reference to `dlsym'
lp_lib.c:(.text+0x7d8a): undefined reference to `dlsym'
lp_lib.c:(.text+0x7da6): undefined reference to `dlsym'
lp_lib.c:(.text+0x7dc2): undefined reference to `dlsym'
liblpsolve55.a(lp_lib.o): In function `set_BFP':
lp_lib.c:(.text+0x7eb4): undefined reference to `dlclose'
lp_lib.c:(.text+0x7fc3): undefined reference to `dlopen'
lp_lib.c:(.text+0x7fe1): undefined reference to `dlsym'
lp_lib.c:(.text+0x831a): undefined reference to `dlsym'
lp_lib.c:(.text+0x8336): undefined reference to `dlsym'
lp_lib.c:(.text+0x8352): undefined reference to `dlsym'
lp_lib.c:(.text+0x836e): undefined reference to `dlsym'
liblpsolve55.a(lp_lib.o):lp_lib.c:(.text+0x838a): more undefined references to `dlsym' follow
................
I understand that the lp_solve libraries are not loaded in my code. Can you please tell me how I can properly link the lp_solve libraries?
You're just missing some compiler flags to include the proper libraries. As danielko said, a quick google search on the missing libraries brings up some suggestions. E.g.
Linux c++ error: undefined reference to 'dlopen'
http://sourceforge.net/p/dev-cpp/discussion/48211/thread/3bd8b8a1
These suggest your compilation should be something more like:
cc -o demo demo.c -ldl -llpsolve55
and the lpsolve documentation suggests a command that includes the project directory such as:
cc -I/lp_solve_5.5 -I/lp_solve_5.5/bfp -I/lp_solve_5.5/bfp/bfp_etaPFI -I/lp_solve_5.5/colamd $src -o MyExe.exe -lm -ldl

Undefined referencs when linking to OpenGL on cygwin

I have a problem with linking while runing my Makefile. I have
installed freeglut on cygwin and tried to build my project. It works
OK in MSVS, but I get following errors:
g++ -static obj/MatrixDistortion.o obj/LookAt.o obj/MatrixT.o obj/Matrix2d.o obj/Camera.o obj/Grid.o obj/s_w_project.o obj/Scene.o -o SWproject -L/usr/lib -L/usr/X11/lib -L/lib/cygwin -L/usr/local/lib -lglut -lopengl32 -lglu32
obj/Grid.o:Grid.cpp:(.text+0xa36): undefined reference to `_glPushMatrix'
obj/Grid.o:Grid.cpp:(.text+0xa87): undefined reference to `_glMultMatrixd'
obj/Grid.o:Grid.cpp:(.text+0xaac): undefined reference to `_glTranslatef'
obj/Grid.o:Grid.cpp:(.text+0xab8): undefined reference to `_glClear'
obj/Grid.o:Grid.cpp:(.text+0xad7): undefined reference to `_glColor3f'
obj/Grid.o:Grid.cpp:(.text+0xae3): undefined reference to `_glBegin'
obj/Grid.o:Grid.cpp:(.text+0xb2c): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xb4f): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xbb4): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xbd7): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xc1e): undefined reference to `_glColor3f'
obj/Grid.o:Grid.cpp:(.text+0xc3d): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xc5c): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xc7b): undefined reference to `_glColor3f'
obj/Grid.o:Grid.cpp:(.text+0xc9a): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xcb9): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xcd8): undefined reference to `_glColor3f'
obj/Grid.o:Grid.cpp:(.text+0xcf7): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xd16): undefined reference to `_glVertex3f'
obj/Grid.o:Grid.cpp:(.text+0xd1b): undefined reference to `_glEnd'
obj/Grid.o:Grid.cpp:(.text+0xd20): undefined reference to `_glPopMatrix'
obj/Grid.o:Grid.cpp:(.text+0xd25): undefined reference to `_glFlush'
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/ld: obj/Grid.o: bad reloc address 0xd in section `.text$_ZNSt4listIP6CameraSaIS1_EED1Ev[std::list<Camera*, std::allocator<Camera*> >::~list()]'
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/ld: final link failed: Invalid operation
collect2: ld returned 1 exit status
Makefile:14: recipe for target `SWproject' failed
I have passed the libraries to g++ as can be seen in the compiler invocation.
Do I have to install GL separately, but in that case why don't I get an error on #include <GL/gl.h>?

Compilation error in GCC on Linux

I am trying to compile my code for GnuTLS, but on compiling it gives the following errors.
I have checked gnutls.h is present on my system in /usr/include/gnutls/.
What else can be the cause?
gcc -o tls.o tls.c
/tmp/ccfyZ1Bd.o: In function `main':
tls.c:(.text+0x1c): undefined reference to `gnutls_global_init'
tls.c:(.text+0x28): undefined reference to `gnutls_anon_allocate_client_credentials'
tls.c:(.text+0x3c): undefined reference to `gnutls_init'
tls.c:(.text+0x58): undefined reference to `gnutls_priority_set_direct'
tls.c:(.text+0x74): undefined reference to `gnutls_credentials_set'
tls.c:(.text+0x79): undefined reference to `tcp_connect'
tls.c:(.text+0x91): undefined reference to `gnutls_transport_set_ptr'
tls.c:(.text+0x9d): undefined reference to `gnutls_handshake'
tls.c:(.text+0xdc): undefined reference to `gnutls_perror'
tls.c:(.text+0x109): undefined reference to `gnutls_record_send'
tls.c:(.text+0x125): undefined reference to `gnutls_record_recv'
tls.c:(.text+0x154): undefined reference to `gnutls_strerror'
tls.c:(.text+0x1e6): undefined reference to `gnutls_bye'
tls.c:(.text+0x1f2): undefined reference to `tcp_close'
tls.c:(.text+0x1fe): undefined reference to `gnutls_deinit'
tls.c:(.text+0x20a): undefined reference to `gnutls_anon_free_client_credentials'
tls.c:(.text+0x20f): undefined reference to `gnutls_global_deinit'
collect2: ld returned 1 exit status
This is a linking error. You need to include some library with the -l flag. Taking a wild guess without knowing your setup, I would try -lgnutls

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