c++ - Makefile: (.text+0x20): undefined reference to `main' collect2: error: ld returned 1 退出状态

Question

Makefile 有问题。也许问题是链接器，但我不能找到错误。在某些时候 (CXX) $(CXXFLAGS) $(LDFLAGS) $^ $(ROOTLIBS) -o @

(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status
Makefile:65: recipe for target 'doMyAnalysisHeavyIon' failed
make: *** [doMyAnalysisHeavyIon] Error 1

生成文件:

  1 all: libs programs
  2 
  3 libs: HxSimParticle_cxx.so HxSimEvent_cxx.so
  4 
  5 programs  = doMyAnalysisHeavyIon
  6 
  7 #LHAPDF    = LHAPDF-6.1.6
  8 PYTHIA8   = /home/andre/pythia8235
  9 HXPATH    = /home/andre/pythia8235/examples/Analysis
 10 
 11 # define compiler/linker flags
 12 CXX       = g++
 13 
 14 CXXFLAGS  = -O3 -Wall -fPIC
 15 CXXFLAGS += $(shell root-config --cflags)
 16 CXXFLAGS += $(shell fastjet-config --cxxflags)
 17 CXXFLAGS += -I$(HXPATH)
 18 
 19 #LDFLAGS   = -O3
 20 LDFLAGS   = -O3 -Wl,-rpath,'$(HXPATH)'
 21 LDFLAGS  += $(shell root-config --ldflags)
 22 #LDFLAGS  += -Wl,-rpath,$(PYTHIA8)/lib/
 23 #LDFLAGS  += -Wl,-rpath,$(HXPATH)/
 24 
 25 SOFLAGS   = -shared
 26 
 27 ROOTLIBS  = $(shell root-config --libs --glibs --evelibs)
 28 #ROOTLIBS += -lEG -lGui -lASImage -lASImageGui
 29 
 30 #PDFLIBS   = $(shell ${LHAPDF}/install/bin/lhapdf-config --libs)
 31 #P8LIBS     = $(shell $(PYTHIA8)/bin/pythia8-config --libs)
 32 
 33 #HXLIBS    = $(HXPATH)/HxSimParticle_cxx.so $(HXPATH)/HxSimEvent_cxx.so
 34 
 35 PROGRAMS = doMyAnalysisHeavyIon
 36 
 37 # compile/link HxSimEvent
 38 HxSimEvent_cxx.so: HxSimEventDict.o HxSimEvent.o HxSimParticleDict.o HxSimParticle.o
 39         $(CXX) $(SOFLAGS) $(LDFLAGS) $^ $(ROOTLIBS) -o $@ 
 40 
 41 HxSimEvent.o: HxSimEvent.cxx
 42         $(CXX) $(CXXFLAGS) -c $^ -o $@ 
 43 
 44 HxSimEventDict.o: HxSimEventDict.cxx
 45         $(CXX) $(CXXFLAGS) -c $^ -o $@ 
 46 
 47 HxSimEventDict.cxx: HxSimEvent.h HxSimEventLinkDef.h
 48         rootcint -f $@ -c $(CXXFLAGS) -p $^
 49 
 50 # compile/link HxSimParticle
 51 HxSimParticle_cxx.so: HxSimParticleDict.o HxSimParticle.o
 52         $(CXX) $(SOFLAGS) $(LDFLAGS) $^ $(ROOTLIBS) -o $@ 
 53 
 54 HxSimParticle.o: HxSimParticle.cxx
 55         $(CXX) $(CXXFLAGS) -c $^ -o $@ 
 56 
 57 HxSimParticleDict.o: HxSimParticleDict.cxx
 58         $(CXX) $(CXXFLAGS) -c $^ -o $@ 
 59 
 60 HxSimParticleDict.cxx: HxSimParticle.h HxSimParticleLinkDef.h
 61         rootcint -f $@ -c $(CXXFLAGS) -p $^
 62 
 63 # compile/link doMyAnalysisHeavyIon 
 64 doMyAnalysisHeavyIon: doMyAnalysisHeavyIon.o HxSimEvent_cxx.so HxSimParticle_cxx.so
 65         $(CXX) $(CXXFLAGS) $(LDFLAGS) $^ $(ROOTLIBS) -o @
 66 
 67 doMyAnalysisHeavyIon.o: doMyAnalysisHeavyIon.C
 68         $(CXX) $(CXXFLAGS) -c $^ -o $@
 69 
 70 .PHONY: clean distclean
 71 
 72 # remove object files
 73 clean:
 74         @rm -f *.o
 75 
 76 # remove objects, libraries and dicts
 77 distclean: clean
 78         @rm -f *.so *Dict.* $(PROGRAMS)

Answer 1

在构建可执行链接器 (ld) 时，正在寻找 main() 以将其用作调用/启动程序的函数。最可能的原因是:

• 您忘记编译定义了 main 的对象中的源代码/链接。通常我希望您将它与您的 Makefile 内容放在 doMyAnalysisHeavyIon.C 中。然而，它被列为编译和链接到 doMyAnalysisHeavyIon 的先决条件。
• 或者有一个拼写错误(也许是大写？)导致在那里找不到main？ (假设它真的没有完全丢失？结果应该是一个可执行文件还是一个库？)