CppuTest: undefined reference to pthread during final linking

Question

I'm a newby in cppuTest and actually I'm trying to build the ./examples within the CppuTest root directory. Source and Test files are compiled without problems but I'm stucking on the final linking stage where I get this error:

C:\CppUTest\cpputest-3.7.1\examples>make
compiling AllTests.cpp
compiling CircularBufferTest.cpp
compiling EventDispatcherTest.cpp
compiling HelloTest.cpp
compiling MockDocumentationTest.cpp
compiling PrinterTest.cpp
compiling CircularBuffer.cpp
compiling EventDispatcher.cpp
compiling Printer.cpp
compiling hello.c
Building archive lib/libCppUTestExamples.a
a - objs/ApplicationLib/CircularBuffer.o
a - objs/ApplicationLib/EventDispatcher.o
a - objs/ApplicationLib/Printer.o
a - objs/ApplicationLib/hello.o
Linking CppUTestExamples_tests
../lib/libCppUTest.a(UtestPlatform.cpp.obj): In function     `PThreadMutexCreate':
c:/CppUTest/cpputest-3.7.1/src/Platforms/Gcc/UtestPlatform.cpp:248:     undefined reference to `_imp__pthread_mutex_init'
../lib/libCppUTest.a(UtestPlatform.cpp.obj): In function `PThreadMutexLock':
c:/CppUTest/cpputest-3.7.1/src/Platforms/Gcc/UtestPlatform.cpp:255:     undefined reference to `_imp__pthread_mutex_lock'
../lib/libCppUTest.a(UtestPlatform.cpp.obj): In function     `PThreadMutexUnlock':
c:/CppUTest/cpputest-3.7.1/src/Platforms/Gcc/UtestPlatform.cpp:260:     undefined reference to `_imp__pthread_mutex_unlock'
../lib/libCppUTest.a(UtestPlatform.cpp.obj): In function     `PThreadMutexDestroy':
c:/CppUTest/cpputest-3.7.1/src/Platforms/Gcc/UtestPlatform.cpp:266:     undefined reference to `_imp__pthread_mutex_destroy'
collect2.exe: error: ld returned 1 exit status
make: *** [CppUTestExamples_tests] Error 1

I'm using MinGW on Windows 7. The MinGW contains also the pthread.a library. My makefil look as follows:

#---------
#
# CppUTest Examples Makefile
#
#----------

#Set this to @ to keep the makefile quiet
ifndef SILENCE
    SILENCE = @
endif

#--- Inputs ----#
COMPONENT_NAME = CppUTestExamples
CPPUTEST_HOME = ..

CPPUTEST_USE_EXTENSIONS = Y
CPP_PLATFORM = Gcc

CFLAGS = -Dmalloc=cpputest_malloc -Dfree=cpputest_free
CPPFLAGS =
GCOVFLAGS = -fprofile-arcs -ftest-coverage

LDFLAGS = -lpthread
#USER_LIBS = -lpthread

# This line is overriding the default new macros.  This is helpful
# when using std library includes like <list> and other containers
# so that memory leak detection does not conflict with stl.
CPPUTEST_MEMLEAK_DETECTOR_NEW_MACRO_FILE = -include     ApplicationLib/ExamplesNewOverrides.h
SRC_DIRS = \
    ApplicationLib

TEST_SRC_DIRS = \
    AllTests

INCLUDE_DIRS =\
  .\
  ApplicationLib\
  $(CPPUTEST_HOME)/include\

include $(CPPUTEST_HOME)/build/MakefileWorker.mk

As you can see the pthread lib is given to the linker with the LDFLAGS....

somebody similar experience? or maybe knows where the problem is? Will be thankful for any tips!

Answer 1

thx to @Keith Marshall and @MadScientist,

so instead of LDFLAGS = -lpthread

I used:

LD_LIBRARIES += -lpthread

and placed this line directly before:

include $(CPPUTEST_HOME)/build/MakefileWorker.mk

Now it works.

Answer 2

As can be seen in the Catalogue of Built-In Rules:

Linking a single object file

n is made automatically from n.o by running the linker (usually called ld) via the C compiler. The precise recipe used is:

$(CC) $(LDFLAGS) n.o $(LOADLIBES) $(LDLIBS)

and Variables Used by Implicit Rules:

LDFLAGS

Extra flags to give to compilers when they are supposed to invoke the linker, ld, such as -L. Libraries (-lfoo) should be added to the LDLIBS variable instead.

So in this case -lpthread should be set or added to LDLIBS, not LDFLAGS.