[英]Error-flood when compiling simple hello world program
我正在尝试编译一个简单的hello world程序:
main.cpp
#include <iostream>
#include <test/t.hpp>
int main( int argc , char** args )
{
std::cout << test() << std::endl;
int x;
std::cin >> x;
return 0;
}
测试/t.hpp
#ifndef TEST_T_HPP_INCLUDED
#define TEST_T_HPP_INCLUDED
int test();
#endif // TEST_T_HPP_INCLUDED
测试/t.cpp
#include <test/t.hpp>
int test()
{
return 42;
}
使用此makefile:
executable_name = testapp
cpp_compiler = g++
cpp_compiler_flags += -std=c++14
cpp_compiler_flags += -g
cpp_linker_flags += -g
linked_libraries +=
included_directories += -I./src/
source_dir = src
source_files += main.cpp
source_files += test/t.cpp
object_dir = obj
object_files = $(addprefix $(object_dir)/,$(source_files:=.o))
directories = $(sort $(foreach i,$(object_files),$(dir $i)))
source_files := $(addprefix $(source_dir)/,$(source_files))
all: make_directories tool
tool: $(object_files)
$(cpp_compiler) $(cpp_linker_flags) -o $(executable_name) $(object_files) $(linked_libraries)
$(object_files): $(source_files)
$(cpp_compiler) $^ $(cpp_compiler_flags) $(included_directories) -o $@
make_directories:
@sh -c \
'for d in $(directories); do \
if [ ! -d $$d ]; \
then echo mkdir -p $$d; mkdir -p $$d; \
fi \
done'
通过使用CodeBlocks 13.12(和mingw32-make)随附的TDM-GCC-4.8.1工具
但是我收到超过10000个错误,如下所示:
obj/src/main.cpp.o:crtend.c:(.text+0x26a80): first defined here
obj/src/test/t.cpp.o:crtend.c:(.text+0x26880): multiple definition of `std::__us
e_cache<std::__numpunct_cache<char> >::operator()(std::locale const&) const'
obj/src/main.cpp.o:crtend.c:(.text+0x26880): first defined here
obj/src/test/t.cpp.o:crtend.c:(.text+0x350d0): multiple definition of `std::ostr
eambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambu
f_iterator<char, std::char_traits<char> > >::_M_insert_float<double>(std::ostrea
mbuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, char, double
) const'
obj/src/main.cpp.o:crtend.c:(.text+0x350d0): first defined here
obj/src/test/t.cpp.o:crtend.c:(.text+0x35ee0): multiple definition of `std::num_
put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std:
:ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, doubl
e) const'
obj/src/main.cpp.o:crtend.c:(.text+0x35ee0): first defined here
我猜这是链接器错误,正如我可以瞬间看到要编译的源文件。
我在这里想念什么?
编辑
这条规则使它起作用:
$(object_files): $(object_dir)/%.o : $(source_dir)/%
$(cpp_compiler) -c $^ $(cpp_compiler_flags) $(included_directories) -o $@
问题在这里:
$(object_files): $(source_files)
$(cpp_compiler) $^ $(cpp_compiler_flags) $(included_directories) -o $@
此配方使所有源文件成为每个目标文件的先决条件。 因此,当Make尝试构建main.o
,它将执行
g++ ... main.cpp test/t.cpp -o main.o
一切都进入main.o
, 一切都进入to
,所以当连接器试图将目标文件链接在一起,它无处不在,击中多个定义。
尝试使用静态模式规则:
$(object_files): $(object_dir)/%.o: %.cpp
$(cpp_compiler) $< $(cpp_compiler_flags) $(included_directories) -o $@
编辑:
PS,您可能需要帮助来找到t.cpp
:
vpath %.cpp test
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.