linux – GCC错误消息“错误：不支持’mov’”是什么意思？

我只是想编译一些我从书中输入的简单示例代码,GCC给出了上述错误.这是我的代码：

$cat -n test.cpp
 1  #define READ_COMMAND    3
 2  
 3  #define MSG_LENGTH  128
 4  
 5  #include dio.h>
 7  
 8  int main(int argc,char *arg[])
 9  {
10      int syslog_command = READ_COMMAND;
11      int bytes_to_read = MSG_LENGTH;
12      int retval;
13      char buffer[MSG_LENGTH];
14  
15      asm volatile(
16          "movl %1,%%ebx\n\t"
17          "movl %2,%%ecx\n\t"
18          "movl %3,%%edx\n\t"
19          "movl $103,%%eax\n\t"
20          "int $128\n\t"
21          "movl %%eax,%0"
22          :"=r" (retval)
23          :"m"(syslog_command),"r"(buffer),"m"(bytes_to_read)
24          :"%eax","%ebx","%ecx","%edx");
25      if (retval > 0) printf("%s\n",buffer);
26  
27  }
28  
29

代码应该调用syslog()系统调用来从内核printk()环形缓冲区读取最后128个字节.以下是有关我的操作系统和系统配置的一些信息：

uname -a：

Linux 3.2.0-26-generic #41-Ubuntu SMP Thu Jun 14 17:49:24 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

gcc -v：

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu

Configured with: ../src/configure -v –with-pkgversion=’Ubuntu/Linaro 4.6.3-1ubuntu5′ –with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs –enable-languages=c,c++,fortran,objc,obj-c++ –prefix=/usr –program-suffix=-4.6 –enable-shared –enable-linker-build-id –with-system-zlib –libexecdir=/usr/lib –without-included-gettext –enable-threads=posix –with-gxx-include-dir=/usr/include/c++/4.6 –libdir=/usr/lib –enable-nls –with-sysroot=/ –enable-clocale=gnu –enable-libstdcxx-debug –enable-libstdcxx-time=yes –enable-gnu-unique-object –enable-plugin –enable-objc-gc –disable-werror –with-arch-32=i686 –with-tune=generic –enable-checking=release –build=x86_64-linux-gnu –host=x86_64-linux-gnu –target=x86_64-linux-gnu

Thread model: posix
gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)

下面是完整的错误：

$gcc test.cpp
test.cpp: Assembler messages:
test.cpp:25: Error: unsupported for `mov'

最佳答案

您正在尝试在64位计算机上编译32位汇编代码.您列出的内联汇编编译为：

movl -24(%rbp),%ebx
movl %rsi,%ecx       <--- error here
movl -28(%rbp),%edx
movl $103,%eax
int $128
movl %eax,%r12d

如您所见,您试图在32位寄存器中存储64位寄存器,这是非法的.更重要的是,这也不是64位ABI系统调用协议.

尝试使用-m32进行编译以强制使用32位ABI.

linux – GCC错误消息“错误：不支持’mov’”是什么意思？

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