Question

我正在尝试在linux上编译一些我知道在OSX上编译的代码，但是我遇到了一些问题。

所有文件都有名为.h的标题，所有文件都在同一目录中。我正在编译：

gcc *.c -std=c99 -lpthread

虽然这段代码在OSX上编译，但我在Ubuntu安装上遇到了一堆奇怪的链接器错误。我错过了一些编译器选项吗？这是默认的Ubuntu服务器安装，其中安装了其他软件包gcc和build-essential。

In file included from errorLogger.h:24:0,
                 from configParser.h:17,
                 from configParser.c:9:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
configParser.c: In function ‘parseConfigFile’:
configParser.c:114:5: warning: implicit declaration of function ‘getline’ [-Wimplicit-function-declaration]
In file included from errorLogger.h:24:0,
                 from global.h:18,
                 from connection.h:19,
                 from connection.c:10:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
connection.c: In function ‘createConnectionQueue’:
connection.c:189:28: warning: assignment makes integer from pointer without a cast [enabled by default]
In file included from errorLogger.h:24:0,
                 from database.h:16,
                 from database.c:9:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
In file included from errorLogger.h:24:0,
                 from errorLogger.c:10:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
errorLogger.c: In function ‘reportError’:
errorLogger.c:63:5: warning: implicit declaration of function ‘strerror_r’ [-Wimplicit-function-declaration]
errorLogger.c: In function ‘logMessage’:
errorLogger.c:87:5: warning: implicit declaration of function ‘localtime_r’ [-Wimplicit-function-declaration]
errorLogger.c: In function ‘processErrorQueue’:
errorLogger.c:131:17: warning: implicit declaration of function ‘open’ [-Wimplicit-function-declaration]
errorLogger.c:131:57: error: ‘O_APPEND’ undeclared (first use in this function)
errorLogger.c:131:57: note: each undeclared identifier is reported only once for each function it appears in
errorLogger.c:131:68: error: ‘O_CREAT’ undeclared (first use in this function)
errorLogger.c:131:78: error: ‘O_WRONLY’ undeclared (first use in this function)
errorLogger.c:131:88: error: ‘S_IWRITE’ undeclared (first use in this function)
errorLogger.c:131:99: error: ‘S_IREAD’ undeclared (first use in this function)
errorLogger.c:146:13: warning: implicit declaration of function ‘fsync’ [-Wimplicit-function-declaration]
errorLogger.c: In function ‘startErrorLogger’:
errorLogger.c:167:36: error: ‘O_APPEND’ undeclared (first use in this function)
errorLogger.c:167:47: error: ‘O_CREAT’ undeclared (first use in this function)
errorLogger.c:167:57: error: ‘O_WRONLY’ undeclared (first use in this function)
errorLogger.c:167:67: error: ‘S_IWRITE’ undeclared (first use in this function)
errorLogger.c:167:78: error: ‘S_IREAD’ undeclared (first use in this function)
errorLogger.c:214:57: error: ‘O_EXCL’ undeclared (first use in this function)
errorLogger.c:231:27: warning: assignment makes integer from pointer without a cast [enabled by default]
errorLogger.c: In function ‘closeErrorLogger’:
errorLogger.c:246:9: warning: implicit declaration of function ‘pthread_kill’ [-Wimplicit-function-declaration]
In file included from errorLogger.h:24:0,
                 from global.h:18,
                 from global.c:9:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
In file included from main.c:23:0:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
main.c: In function ‘main’:
main.c:53:5: warning: implicit declaration of function ‘blockSignals’ [-Wimplicit-function-declaration]
main.c:61:45: error: invalid application of ‘sizeof’ to incomplete type ‘struct addrinfo’ 
main.c:62:29: error: invalid application of ‘sizeof’ to incomplete type ‘struct addrinfo’ 
main.c:64:10: error: dereferencing pointer to incomplete type
main.c:65:10: error: dereferencing pointer to incomplete type
main.c:66:10: error: dereferencing pointer to incomplete type
main.c:66:23: error: ‘AI_PASSIVE’ undeclared (first use in this function)
main.c:66:23: note: each undeclared identifier is reported only once for each function it appears in
main.c:69:5: warning: implicit declaration of function ‘getaddrinfo’ [-Wimplicit-function-declaration]
main.c:73:9: warning: implicit declaration of function ‘gai_strerror’ [-Wimplicit-function-declaration]
main.c:73:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 4 has type ‘int’ [-Wformat]
main.c:73:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 4 has type ‘int’ [-Wformat]
main.c:81:41: error: dereferencing pointer to incomplete type
main.c:83:30: error: dereferencing pointer to incomplete type
main.c:83:46: error: dereferencing pointer to incomplete type
main.c:83:64: error: dereferencing pointer to incomplete type
main.c:96:30: error: dereferencing pointer to incomplete type
main.c:96:44: error: dereferencing pointer to incomplete type
main.c:112:5: warning: implicit declaration of function ‘freeaddrinfo’ [-Wimplicit-function-declaration]
main.c:138:9: error: unknown type name ‘fd_set’
main.c:142:9: warning: implicit declaration of function ‘FD_ZERO’ [-Wimplicit-function-declaration]
main.c:143:9: warning: implicit declaration of function ‘FD_SET’ [-Wimplicit-function-declaration]
main.c:145:9: warning: implicit declaration of function ‘pselect’ [-Wimplicit-function-declaration]
In file included from signalHandling.c:10:0:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
signalHandling.c:12:18: error: unknown type name ‘sigset_t’
signalHandling.c: In function ‘setHandler’:
signalHandling.c:51:53: error: invalid application of ‘sizeof’ to incomplete type ‘struct sigaction’ 
signalHandling.c:52:36: error: invalid application of ‘sizeof’ to incomplete type ‘struct sigaction’ 
signalHandling.c:54:5: warning: implicit declaration of function ‘sigemptyset’ [-Wimplicit-function-declaration]
signalHandling.c:54:30: error: dereferencing pointer to incomplete type
signalHandling.c:60:9: warning: implicit declaration of function ‘sigaddset’ [-Wimplicit-function-declaration]
signalHandling.c:60:35: error: dereferencing pointer to incomplete type
signalHandling.c:67:17: error: dereferencing pointer to incomplete type
signalHandling.c:72:9: warning: implicit declaration of function ‘sigaction’ [-Wimplicit-function-declaration]

Answer 1

您可能遗漏了一些在OS X上隐式引入的#include，但在Linux上却没有。

从错误消息判断，您可能至少缺少包括：

<signal.h>（适用于sigset_t及其他人）
<fcntl.h>（适用于O_*）
<unistd.h>（对于一堆东西）
<netdb.h>（针对各种网络功能和常量）
<stdio.h>（适用于getline）

您可能还需要定义一些功能宏（例如_POSIX_C_SOURCE）以获取某些与系统相关的功能，包括strerror_r和pselect。

Answer 2

我假设最直接的目标是让代码完全编译，并且一旦完成，你将返回并修改源代码，以便在两个平台上开箱即用。这意味着短时间内可以接受黑客攻击;当您了解可移植性问题时，它们将得到妥善修复。（如果有任何安慰，那么最初开发软件的第一个替代系统通常是最难的;之后，通常会变得更容易。）

首先要尝试的是：

gcc *.c -std=gnu99 -lpthread

这告诉系统头文件定义比-std=c99更多的符号。（对此主题有一些不同意见，这是可以的。至少，如果将-pedantic添加到-std=c99编译中，除非您还请求POSIX，否则不会公开POSIX定义的标准C标头中的符号。支持 - 见下文。由于你没有-pedantic，这可能不是编辑中的一个因素，在这种情况下，悄悄地转向下一个建议，这是未来POSIX系统可移植性的基础。）

如果这不足以让你重回正轨，那么你可能需要使用类似的东西：

gcc *.c -std=gnu99 -D_XOPEN_SOURCE=700 -lpthread

这说“向我提供与POSIX 2008相对应的POSIX和X / Open功能”。对于旧版本，您可以尝试600和500，但您可能不需要在Linux上执行此操作。在适当的时候，您可能会通过配置标头或配置工具自动设置_XOPEN_SOURCE。在你完成编译的过程中，在命令行中指定它是可以的。在适当的时候，您将使用makefile或等效项来控制编译，而不是在shell中键入gcc命令行。）

sigset_t在POSIX下的<signal.h>中定义。因此，明确请求POSIX支持应该让事情再次正确编译。如果你仍然得到诸如sigset_t未声明的类型，那么Mac OS X上必须有一个包含标准标题的标题，例如<signal.h>，但它在Linux上执行一些不相关的任务（因此不包括<signal.h>）。这将需要源代码审查。但是，它不太可能是必要的。

Answer 3

您需要包含其他头文件，因为不同的系统头包含其他不同的系统头。

另外，例如gcc一直在努力不包括它不应该包含的标题。

signalHandling.h是否包含#include <signal.h>，其中定义了sigset_t？

修改

与OP交谈后，问题似乎是编译/链接问题。首先将源代码编译成目标文件，然后将它们链接起来似乎已经解决了它们的问题。

Linux上C代码的编译错误（在OSX上编译相同的代码）

3 个答案: