error during making GTest

Question

I was trying to set up GTest environment on my Ubuntu machine. but while making the GTest to get the library, i get the following error...

som@som-VPCEH25EN:~/Workspace/CPP/gtest-1.6.0/make$ make
g++ -I../include -g -Wall -Wextra -lpthread sample1.o sample1_unittest.o gtest_main.a -o sample1_unittest
gtest_main.a(gtest-all.o): In function `~ThreadLocal':
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1336: undefined reference to `pthread_getspecific'
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1340: undefined reference to `pthread_key_delete'
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1336: undefined reference to `pthread_getspecific'
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1340: undefined reference to `pthread_key_delete'
gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocator<testing::internal::TraceInfo> > >::GetOrCreateValue() const':
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1372: undefined reference to `pthread_getspecific'
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1379: undefined reference to `pthread_setspecific'
gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<testing::TestPartResultReporterInterface*>::CreateKey()':
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1365: undefined reference to `pthread_key_create'
gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocator<testing::internal::TraceInfo> > >::CreateKey()':
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1365: undefined reference to `pthread_key_create'
gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<testing::TestPartResultReporterInterface*>::GetOrCreateValue() const':
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1372: undefined reference to `pthread_getspecific'
/home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1379: undefined reference to `pthread_setspecific'
collect2: ld returned 1 exit status
make: *** [sample1_unittest] Error 1

Answer 1

Try moving -lpthread to after gtest_main.a in your g++ command.

Answer 2

Have you seen Erik Smistad's excellent tutorial on how to get started w/ gtest on Ubuntu? I've just tried it on (K)ubuntu 12.04 and it worked perfectly. In short, what you need to do is

sudo apt-get install cmake libgtest-dev
cd /usr/src/gtest
sudo cmake CMakeLists.txt
sudo make
sudo cp *.a /usr/lib

If you feel uncomfortable running make and cmake as root, you'd have to copy /usr/src/gtest to a directory writable by your user. In the tutorial, Erik also provides a sample test with a CMakeLists.txt to build it.

Answer 3

Put "-L/usr/local/$(uname -m)-linux-gnu" in your LDFLAGS and "-pthread" in your linker (ld) command line. (Yes, that's -pthread, not -lpthread)

Answer 4

I had the same problem and I changed -lpthread in the Makefile to -pthread. (I dropped out the small 'L'.) After that a 'make' compiled without errors.

Answer 5

File in gtest-1.6.0/make You should have Makefile see below how should it look. Difference is on last line

# A sample Makefile for building Google Test and using it in user
# tests.  Please tweak it to suit your environment and project.  You
# may want to move it to your project's root directory.
#
# SYNOPSIS:
#
#   make [all]  - makes everything.
#   make TARGET - makes the given target.
#   make clean  - removes all files generated by make.

# Please tweak the following variable definitions as needed by your
# project, except GTEST_HEADERS, which you can use in your own targets
# but shouldn't modify.

# Points to the root of Google Test, relative to where this file is.
# Remember to tweak this if you move this file.
GTEST_DIR = ..

# Where to find user code.
USER_DIR = ../samples

# Flags passed to the preprocessor.
CPPFLAGS += -I$(GTEST_DIR)/include

# Flags passed to the C++ compiler.
CXXFLAGS += -g -Wall -Wextra

# All tests produced by this Makefile.  Remember to add new tests you
# created to the list.
TESTS = sample1_unittest

# All Google Test headers.  Usually you shouldn't change this
# definition.
GTEST_HEADERS = $(GTEST_DIR)/include/gtest/*.h \
                $(GTEST_DIR)/include/gtest/internal/*.h

# House-keeping build targets.

all : $(TESTS)

clean :
    rm -f $(TESTS) gtest.a gtest_main.a *.o

# Builds gtest.a and gtest_main.a.

# Usually you shouldn't tweak such internal variables, indicated by a
# trailing _.
GTEST_SRCS_ = $(GTEST_DIR)/src/*.cc $(GTEST_DIR)/src/*.h $(GTEST_HEADERS)

# For simplicity and to avoid depending on Google Test's
# implementation details, the dependencies specified below are
# conservative and not optimized.  This is fine as Google Test
# compiles fast and for ordinary users its source rarely changes.
gtest-all.o : $(GTEST_SRCS_)
    $(CXX) $(CPPFLAGS) -I$(GTEST_DIR) $(CXXFLAGS) -c \
            $(GTEST_DIR)/src/gtest-all.cc

gtest_main.o : $(GTEST_SRCS_)
    $(CXX) $(CPPFLAGS) -I$(GTEST_DIR) $(CXXFLAGS) -c \
            $(GTEST_DIR)/src/gtest_main.cc

gtest.a : gtest-all.o
    $(AR) $(ARFLAGS) $@ $^

gtest_main.a : gtest-all.o gtest_main.o
    $(AR) $(ARFLAGS) $@ $^

# Builds a sample test.  A test should link with either gtest.a or
# gtest_main.a, depending on whether it defines its own main()
# function.

sample1.o : $(USER_DIR)/sample1.cc $(USER_DIR)/sample1.h $(GTEST_HEADERS)
    $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $(USER_DIR)/sample1.cc

sample1_unittest.o : $(USER_DIR)/sample1_unittest.cc \
                     $(USER_DIR)/sample1.h $(GTEST_HEADERS)
    $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $(USER_DIR)/sample1_unittest.cc

sample1_unittest : sample1.o sample1_unittest.o gtest_main.a
    $(CXX) $(CPPFLAGS) $(CXXFLAGS)  $^ -o $@ -lpthread #<----------------------- DIFF

Next please run make in this directory :) and be happy.