我有以下代码...这是抛出main.cpp:18: undefined reference to phrase_init()来自C#经验C有点烦人，特别是在试图找出问题所在的时候:(任何想法或指针都会非常感谢！
#ifndef PHRASE_H
#define PHRASE_H
typedef struct
{
char* Word1;
char* Word2;
} Phrase;
Phrase* phrase_init(void);
#endif
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include "phrase.h"
Phrase* phrase_init()
{
Phrase* phrase = (Phrase *)malloc(sizeof(Phrase));
phrase->Word1 = (char *)malloc(sizeof(char));
phrase->Word2 = (char *)malloc(sizeof(char));
return phrase;
}
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <cctype>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include "phrase.h"
int main(int argc, char** argv) {
char* word1 = "Testing";
char* word2 = "Word2";
Phrase* test = phrase_init();
strcpy(test->Word1, word1);
strcpy(test->Word2, word2);
printf("Word 1: %s", test->Word1);
printf("Word 2: %s", test->Word2);
scanf("%s", word1);
}
#
# There exist several targets which are by default empty and which can be
# used for execution of your targets. These targets are usually executed
# before and after some main targets. They are:
#
# .build-pre: called before 'build' target
# .build-post: called after 'build' target
# .clean-pre: called before 'clean' target
# .clean-post: called after 'clean' target
# .clobber-pre: called before 'clobber' target
# .clobber-post: called after 'clobber' target
# .all-pre: called before 'all' target
# .all-post: called after 'all' target
# .help-pre: called before 'help' target
# .help-post: called after 'help' target
#
# Targets beginning with '.' are not intended to be called on their own.
#
# Main targets can be executed directly, and they are:
#
# build build a specific configuration
# clean remove built files from a configuration
# clobber remove all built files
# all build all configurations
# help print help mesage
#
# Targets .build-impl, .clean-impl, .clobber-impl, .all-impl, and
# .help-impl are implemented in nbproject/makefile-impl.mk.
#
# Available make variables:
#
# CND_BASEDIR base directory for relative paths
# CND_DISTDIR default top distribution directory (build artifacts)
# CND_BUILDDIR default top build directory (object files, ...)
# CONF name of current configuration
# CND_PLATFORM_${CONF} platform name (current configuration)
# CND_ARTIFACT_DIR_${CONF} directory of build artifact (current configuration)
# CND_ARTIFACT_NAME_${CONF} name of build artifact (current configuration)
# CND_ARTIFACT_PATH_${CONF} path to build artifact (current configuration)
# CND_PACKAGE_DIR_${CONF} directory of package (current configuration)
# CND_PACKAGE_NAME_${CONF} name of package (current configuration)
# CND_PACKAGE_PATH_${CONF} path to package (current configuration)
#
# NOCDDL
# Environment
MKDIR=mkdir
CP=cp
CCADMIN=CCadmin
# build
build: .build-post
.build-pre:
# Add your pre 'build' code here...
.build-post: .build-impl
# Add your post 'build' code here...
# clean
clean: .clean-post
.clean-pre:
# Add your pre 'clean' code here...
.clean-post: .clean-impl
# Add your post 'clean' code here...
# clobber
clobber: .clobber-post
.clobber-pre:
# Add your pre 'clobber' code here...
.clobber-post: .clobber-impl
# Add your post 'clobber' code here...
# all
all: .all-post
.all-pre:
# Add your pre 'all' code here...
.all-post: .all-impl
# Add your post 'all' code here...
# build tests
build-tests: .build-tests-post
.build-tests-pre:
# Add your pre 'build-tests' code here...
.build-tests-post: .build-tests-impl
# Add your post 'build-tests' code here...
# run tests
test: .test-post
.test-pre:
# Add your pre 'test' code here...
.test-post: .test-impl
# Add your post 'test' code here...
# help
help: .help-post
.help-pre:
# Add your pre 'help' code here...
.help-post: .help-impl
# Add your post 'help' code here...
# include project implementation makefile
include nbproject/Makefile-impl.mk
# include project make variables
include nbproject/Makefile-variables.mk
答案 0 :(得分：5)
您必须告诉链接器在哪里找到符号。
例如：
g++ -c phrase.cpp # creates phrase.o which defines phrase_init()
g++ -c main.cpp # creates main.o which refers to phrase_init()
g++ phrase.o main.o -o main # creates executable file "main"
或者，在一个命令中执行以上所有操作：
g++ phrase.cpp main.cpp -o main
请注意，我假设两个源文件都是C ++，并以.cpp扩展名命名。您的问题是指包含.c和.cpp个扩展名的文件，问题标记为c++。
如果你使用的是C，那么你不应该在main.c中使用特定于C ++的标题，而应该使用gcc而不是g++。
如果您使用的是C ++，那么所有源文件都应该有.cpp个后缀，您应该使用g++。
如果您正在尝试混合C和C ++，那么you should be using extern "C"以便编译器知道您在做什么（但通常使用纯C ++更容易）。
答案 1 :(得分：1)
你真的应该使用-Wall -g进行编译，然后添加到Makefile
CXXFLAGS+= -Wall -g
CFLAGS+= -Wall -g
第一个是C ++，第二个是C
我还认为你应该为make手工编写自己的（更简单的）Makefile（而不是复制你不理解的更复杂的Makefile。）