Error while loading shared libraries when running executable - c++

When I make the Makefile everything works fine, I get a library in the directory dir. And when I run "Make test" I get a testfile that I want to run. But when I want to run this file I get this weird error: ./programma: error while loading shared libraries: libprogramma.so: cannot open shared object file: No such file or directory. I have tried running the program on both WSL and Linux, but nothing makes this error go away. Can anyone help me?
Here I have my Makefile which makes the library and the executable:
INC_DIR = include
SRC_DIR = src
SOURCES = $(sort $(shell find $(SRC_DIR) -name '*.cc'))
OBJECTS = $(SOURCES:.cc=.o)
DEPS = $(OBJECTS:.o=.d)
TARGET = programma
CXX = g++
CFLAGS = -Wall -Wextra -Wpedantic -std=c++11
CPPFLAGS = $(addprefix -I, $(INC_DIR))
.PHONY: all clean debug release
release: CFLAGS += -O3 -DNDEBUG
release: all
debug: CFLAGS += -O0 -DDEBUG -ggdb3
debug: all
all: $(TARGET)
clean:
rm -f $(OBJECTS) $(DEPS) lib/*.so programma *.d
$(TARGET): $(OBJECTS)
$(CXX) $(CFLAGS) $(CPPFLAGS) -fPIC -shared -o lib/lib$#.so $^
-include $(DEPS)
%.o: %.cc
$(CXX) $(CFLAGS) $(CPPFLAGS) -fPIC -MMD -o $# -c $<
test:
$(CXX) $(CFLAGS) -L./lib $(CPPFLAGS) -MMD -o programma tests/main.cc -l$(TARGET)

Executables on Linux don't look for shared libraries in the directory they're located in, at least by default.
You can either fix that at link-time, by passing -Wl,-rpath='$ORIGIN', or at runtime, by setting LD_LIBRARY_PATH env variable to the directory with the library. (LD_LIBRARY_PATH=path/to/lib ./programma)

Related

Build Eclipse Makefile project from command line

I have created Eclipse Makefile c++ project with intention to build project also without Eclipse. But I got error while run make in terminal:
Makefile:15: *** Build mode not supported by this Makefile. Stop.
How to fix that? Why I should need Eclipse Makefile if I can't build it with make?
Makefile content:
PROJECT_ROOT = $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
OBJS = boiler.o
ifeq ($(BUILD_MODE),debug)
CFLAGS += -g
else ifeq ($(BUILD_MODE),profile)
CFLAGS += -O2
else ifeq ($(BUILD_MODE),run)
CFLAGS += -O2
else ifeq ($(BUILD_MODE),linuxtools)
CFLAGS += -g -pg -fprofile-arcs -ftest-coverage
LDFLAGS += -pg -fprofile-arcs -ftest-coverage
else
$(error Build mode $(BUILD_MODE) not supported by this Makefile)
endif
all: boiler
boiler: $(OBJS)
$(CXX) $(LDFLAGS) -o $# $^
%.o: $(PROJECT_ROOT)%.cpp
$(CXX) -c $(CFLAGS) $(CXXFLAGS) $(CPPFLAGS) -o $# $<
%.o: $(PROJECT_ROOT)%.c
$(CC) -c $(CFLAGS) $(CPPFLAGS) -o $# $<
clean:
rm -fr boiler $(OBJS)
I'm not sure exactly how you created your Makefile ...
... but the problem is clearly that your Makefile happens to rely on the variable "$(BUILD_MODE)" ...
... and, the way you're running "make", BUILD_MODE isn't being set to one of your options, or isn't being set at all.
SUGGESTION: Type this on the command line: make BUILD_MODE=debug
PS:
Equivalently, you could define BUILD_MODE as an environment variable, e.g. set BUILD_MODE=debug (DOS prompt) or export BUILD_MODE-debug (Linux term)
"BUILD_MODE" isn't "required". It's just a convention. That your "Makefile generator" happened to add when it created your particular makefile.

Makefile does not evaluate OBJECTS variable

I am trying to build a Makefile that will build a shared library with g++ and I find that it is not evaluating the OBJECTS variable. This is on Ubuntu 18.04 and all the files are in the same current directory. Secondly it is completely skipping the source file compilation and proceeding directly to evaluate the linking instruction. As a clarification I am using GNU Make 4.1
Here is what I get when I type make all
g++ -shared -pthread -o tree.so
g++: fatal error: no input files
compilation terminated.
Makefile:12: recipe for target 'tree.so' failed
make: *** [tree.so] Error 1
Here is my Makefile code
CC=g++
CFLAGS = -I/usr/local/include -Wall -std=c++17 -O3 -march=native -Ofast -ftree-vectorize
LIBS=-shared -pthread
SOURCES=$(wildcard *.cpp)
OBJECTS=$(wildcard *.o)
TARGET=tree.so
all:$(TARGET)
$(TARGET) : $(OBJECTS)
$(CC) $(LIBS) -o $(OBJECTS) $(TARGET)
$(OBJECTS):$(SOURCES)
$(CC) -c -g $(CFLAGS) $(SOURCES)
clean:
rm -f $(OBJECTS) $(TARGET)
If you only have the *.cpp files in your directories, then there is not any *.o yet, so your $(wildcard *.o) will expand to nothing.
What you want is to get the *.cpp files and compute the corresponding *.o files:
OBJECTS=$(patsubst %.cpp,%.o,$(SOURCES))
or equivalently:
OBJECTS=$(SOURCES:.cpp=.o)
Now, your compiler command is not the best one, because if you touch any source file all will be compiled. You can use instead:
$(OBJECTS): %.o: %.cpp
$(CC) -c -g $(CFLAGS) $< -o $#
So that only the touched files are actually rebuilt.
Also you have the linking command wrong. It should be:
$(TARGET) : $(OBJECTS)
$(CC) $(LIBS) -o $(TARGET) $(OBJECTS)
because the argument to the -o option is the output file, that is the target.

Shared library with freeglut - undefined symbol

I'm actually experiencing some issues while linking an OpenGL/freeglut shared library (.so) with a C++ project. I'm sure that the problem is in my Makefile since the code I use to load (using the dlopen/dlsym/dlclose functions) works fine with other shared libraries.
I thought it comes from headers inclusions but the OpenGL project I'm trying to work with compiles when I create an executable of it. I've also checked the glut FAQ but the solution now redirect to a dead link So there is my Makefile content, does anyone see where I am wrong ?
TARGET = lib_opengl.so
CC = g++
SRC = GL_Handler.cpp \
GL_Utils.cpp
DEVIL_CFLAGS := $(shell pkg-config --cflags IL)
DEVIL_LIBS := $(shell pkg-config --libs IL)
LIBS += -lGL -lGLU -lglut $(DEVIL_CFLAGS) $(DEVIL_LIBS)
CFLAGS = -W -Werror -Wall -ansi -pedantic -fPIC -shared -L/usr/X11R6/lib/ $(LIBS)
SRCDIR = src
OBJDIR = obj
SOURCES := $(addprefix src/, $(SRC))
OBJECTS := $(SOURCES:$(SRCDIR)/%.cpp=$(OBJDIR)/%.o)
rm = rm -rf
mkdir = mkdir -p
$(TARGET): $(OBJECTS)
#$(CC) $(CFLAGS) -o $# $(OBJECTS)
#echo $(TARGET)" compiled !"
$(OBJECTS): $(OBJDIR)/%.o : $(SRCDIR)/%.cpp
#$(mkdir) $(OBJDIR)
#$(CC) $(CFLAGS) -c $< -o $#
all : $(TARGET)
clean :
#$(rm) $(OBJDIR)
#echo "Binary files deleted"
fclean : clean
#$(rm) $(TARGET) $(LINK)
#echo "Binary and executable files are deleted"
re : fclean all
.PHONY: all clean fclean re
And there is the result when I'm trying to link it with my shared libraries loader.
./so_loader ./lib/lib_opengl.so
./so_loader: symbol lookup error: ./lib/lib_opengl.so: undefined symbol: glutInit
I hope that my problem is understandable and thanks for reading.
As a start, use variable LDFLAGS for linking instead of CFLAGS which is meant for compilation. Something like this:
LDFLAGS = -L/usr/X11R6/lib
...
$(TARGET): LDFLAGS += -shared -Wl,--no-undefined
$(TARGET): $(OBJECTS)
#$(CC) $(LDFLAGS) -o $# $(OBJECTS) ${LIBS}

makefile for boost crossplatform

I have created a makefile for a library I am compiling.
I have already got the makefile working on windows and linux , but there is a different makefile for each OS.
How could I allow this to work on both OS without hardcoding the path to the boost library and boost headers below:
Do I need to add the boost folder to the path variable? do I need to add the library directory to some OS variable?
makefile windows:
# source files.
SRC = protoService.cpp protocolBaseServer.cpp client.cpp
OBJ = $(SRC:.cpp=.o)
OUT = ../libutils.a
# include directories
INCLUDES = -I. -I../include/ -IC:\boost_1_59_0\
# C++ compiler flags (-g -O2 -Wall)
CCFLAGS = -g -MD -MP -std=c++0x -Wall -c
# compiler
CCC = g++
# library paths
LIBS = -LC:\boost_1_59_0\libs -lboost_serialization
# compile flags
LDFLAGS = -g
.SUFFIXES: .cpp
default: $(OUT)
.cpp.o:
$(CCC) $(INCLUDES) $(CCFLAGS) $< -o $#
$(OUT): $(OBJ)
ar rcs $(OUT) $(OBJ)
#depend: dep
#dep:
# makedepend -- $(CFLAGS) -- $(INCLUDES) $(SRC)
clean:
rm -f $(OBJ) $(OUT) Makefile.bak
-include $(DEPS:%.o=%.d)
makefile linux:
# source files.
SRC = protoService.cpp protocolBaseServer.cpp client.cpp
OBJ = $(SRC:.cpp=.o)
OUT = ../libutils.a
# include directories
INCLUDES = -I. -I../include/ -I/usr/local/include -I/usr/share/boost_1_58_0/
# C++ compiler flags (-g -O2 -Wall)
CCFLAGS = -g -MD -MP -std=c++0x -Wall -c
# compiler
CCC = g++
# library paths
LIBS = -L/usr/share/boost_1_58_0/lib/ -lboost_serialization
# compile flags
LDFLAGS = -g
.SUFFIXES: .cpp
default: $(OUT)
.cpp.o:
$(CCC) $(INCLUDES) $(CCFLAGS) $< -o $#
$(OUT): $(OBJ)
ar rcs $(OUT) $(OBJ)
#depend: dep
#dep:
# makedepend -- $(CFLAGS) -- $(INCLUDES) $(SRC)
clean:
rm -f $(OBJ) $(OUT) Makefile.bak
-include $(DEPS:%.o=%.d)
Make passes environment variables to the makefile processor, so you can create make variables based on them.
INC_PATHS := ../include/ .
LIBS += boost_serialization
ifeq ($(OS),"Windows_NT")
INC_PATHS += ../include/ C:/boost_1_59_0/libs
LIBS += boost_serialization
else
INC_PATHS += /usr/local/include /usr/share/boost_1_58_0/lib/
endif
And then
INCLUDES = $(prepend -I,$(INC_PATHS))
or something like that. I'm not in front of make to ensure the syntax is exactly correct, but it should get you moving in the right direction.

cygwin g++ Linker doesn't find shared library

I have been creating a library. When I compile it as a static library, it works fine. Now I want to turn it into a shared library. The library is created and in the proper place, but when I try to compile the client code, the linking phase says that it can't find the library.
I already tried to rename it to al or dylib but that doesn't help either. When I put the -v flag on the linking, I can see that my library path is there. I also tried different paths. I used a relative path, but even with a full path it doesn't find it.
The Makefile from the library:
.SUFFIXES:
.SUFFIXES: .o .cpp
.SUFFIXES: .o .d
CC := g++
LNK:= g++
CXXFLAGS_RELEASE = -fPIC -shared -O2 -Wall -fmessage-length=0
CXXFLAGS_DEBUG = -fPIC -shared -g -Wall -fmessage-length=0 -D _DEBUG
CXXFLAGS = $(CXXFLAGS_DEBUG)
OBJDIR:= obj
SRCDIR:= src
HDIR:= include
INCLUDE_PATHS:= -Iinclude -Iinclude/interfaces -Iinclude/support
CPP_FILES := propertyfile/propertyfile.cpp \
propertyfile/propertyitem.cpp \
propertyfile/propertyfactory.cpp \
helper/string_helper.cpp
OBJ := $(patsubst %.cpp,$(OBJDIR)/%.o, $(CPP_FILES))
SRC := $(patsubst %.cpp,$(SRCDIR)/%.o, $(CPP_FILES))
LIBS:=
TARGET:= libsupport.so
all: $(TARGET)
$(TARGET): $(OBJ)
$(LNK) -o $(TARGET) $(OBJ) -shared
#cp $(TARGET) ../lib
#cp -r include ..
clean:
rm -f $(OBJ) $(ASM) $(TARGET)
-include $(patsubst %.cpp,$(OBJDIR)/%.d, $(CPP_FILES))
$(OBJDIR)/%.o: $(SRCDIR)/%.cpp $(OBJDIR)/%.d
#mkdir -p `dirname $#`
$(CC) $(CXXFLAGS) -c $< -o $# $(INCLUDE_PATHS)
$(OBJDIR)/%.d: $(SRCDIR)/%.cpp
#mkdir -p `dirname $#`
$(CC) $(CXXFLAGS) -MM -MT $# -MF $(OBJDIR)/$*.d -c $< $(INCLUDE_PATHS)
And here is the Makefile for the application:
.SUFFIXES:
.SUFFIXES: .o .cpp
CC := g++
LD := g++
CXXFLAGS_RELEASE = -O2 -Wall -fmessage-length=0
CXXFLAGS_DEBUG = -g -Wall -fmessage-length=0 -D _DEBUG
CXXFLAGS = $(CXXFLAGS_DEBUG)
OBJDIR:= obj
SRCDIR:= src
INCLUDE_PATHS:= -Iinclude -I../include
LIBS:= -L /cygdrive/d/src/c/lib -lsupport
CPP_FILES := nohupshd.cpp \
daemon.cpp \
task.cpp
OBJ := $(patsubst %.cpp,$(OBJDIR)/%.o, $(CPP_FILES))
SRC := $(patsubst %.cpp,$(SRCDIR)/%.o, $(CPP_FILES))
TARGET:= nohupshd
all: $(TARGET)
$(TARGET): $(OBJ)
$(LD) -o $(TARGET) $(OBJ) $(LIBS)
clean:
rm -f $(OBJ) $(ASM) $(TARGET)
-include $(patsubst %.cpp,$(OBJDIR)/%.d, $(CPP_FILES))
$(OBJDIR)/%.o: $(SRCDIR)/%.cpp $(OBJDIR)/%.d
#mkdir -p `dirname $#`
$(CC) $(CXXFLAGS) -c $< -o $# $(INCLUDE_PATHS)
$(OBJDIR)/%.d: $(SRCDIR)/%.cpp
#mkdir -p `dirname $#`
$(CC) $(CXXFLAGS) -MM -MT $# -MF $(OBJDIR)/$*.d -c $< $(INCLUDE_PATHS)
After some experimenting I found a solution on how to compile a shared library under cygwin.
Apparently the compiler is looking for a DLL file even though it is inside cygwin. so the first step is to add your path, where the library is going to be to the PATH variable.
export PATH=$PATH:/cygdrive/d/src/c/lib
Apparently when linking against a shared library, the linker seems to look for a DLL file by default. I don't know why, because inside cygwin I would expect it to look for a .so file just like on other UNIX systems.
However, there are two solutions to this, which both work.
First, you can create a link to your .so library with the name .dll
ln -s /cygdrive/d/src/lib/libsupport.so libsupport.dll
In this case the makefile doesn't have to be changed and -lsupport will find the library while linking. I prefer this solution.
Second, you can specify the linker option with the full name.
LIBS:= -L /cygdrive/d/src/c/lib -l:libsupport.so
then you don't have to create a link.
So the crucial thing seems to be that the shared library must be in the PATH under cygwin. Using LD_LIBRARY_PATH doesn't help in that case as you can link the executable, but when trying to run it, it will not find it.
ldd nohupshd.exe
libsupport.so => not found
UPDATE: For some reason when I checked with ldd, my library was suddenly gone from the list. I found out that cygwin uses the name to differentiate between MS Windows and Unix shared libraries. So in order to make it work, the name of the library must be cyg.so to make it work, otherwise the exectuable seems to be some Windows build. In this case you don't need to create the link named x.dll as the shared library stays inside the Unix environment.
$(LNK) -o cyg$(TARGET).so $(OBJ) -shared
When using eclipse for debugging, the path to the shared library must also be in the windows path environment variable. Otherwise the debug session immediately terminates without an error.