在 GNU 的 C++ 代码中使用 C 头文件.包括内联汇编的错误:“asm"中的不可能约束

I have a weird one. I'm working on an embedded system, using the vendors header files. I'm compiling the files using GCC 4.6.3. I want to use C++ for my code, I have error I can't figure out. I'm running a vendor example program, and all I've done is changed the name of the main.c file to main.cpp. As a result, I assume, the header files are being interpreted by the C++ compiler. One of them contains the following lines:

__attribute__((naked)) static return_type signature 
  { 
     __asm( 
         "svc %0
" 
         "bx r14" : : "I" (number) : "r0" 
     ); 
}

如果文件名为 main.c，则文件编译正确，我认为这是因为 C 编译器正在处理该文件.如果我使用 C++，我得到的错误是

error: impossible constraint in 'asm'

#define syscall(number) __attribute__((naked)) static return_type signature 
  { 
     __asm( 
         "svc " #number "
" 
         "bx r14" : : : "r0" 
     ); 
  }