Clang与Linux内核

Question

我尝试用clang 8.0.0为Linux内核2.6.37代码生成AST文件。我在内核根目录中运行以下命令

clang -emit-ast init/main.c -o astfile -std=c11 -Iinclude -Iarch/x86/include

并获取错误

In file included from /mnt/lfs/sources/linux-2.6.37/init/main.c:12:
/mnt/lfs/sources/linux-2.6.37/include/linux/types.h:13:2: warning: "Attempt to use kernel
      headers from user space, see http://kernelnewbies.org/KernelHeaders" [-W#warnings]
#warning "Attempt to use kernel headers from user space, see http://kernelnewbies...
 ^
In file included from /mnt/lfs/sources/linux-2.6.37/init/main.c:13:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/module.h:9:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/list.h:7:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/prefetch.h:14:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/processor.h:15:
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/current.h:12:8: error: unknown type
      name '__always_inline'
static __always_inline struct task_struct *get_current(void)
       ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/current.h:12:24: error: expected
      identifier or '('
static __always_inline struct task_struct *get_current(void)
                       ^
In file included from /mnt/lfs/sources/linux-2.6.37/init/main.c:13:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/module.h:9:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/list.h:7:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/prefetch.h:14:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/processor.h:17:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/system.h:7:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/cmpxchg.h:4:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/cmpxchg_64.h:4:
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:47:2: error: unknown
      type name 'u8'
        u8 *instr;              /* original instruction */
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:48:2: error: unknown
      type name 'u8'
        u8 *replacement;
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:49:2: error: unknown
      type name 'u16'
        u16 cpuid;              /* cpuid bit set for replacement */
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:50:2: error: unknown
      type name 'u8'
        u8  instrlen;           /* length of original instruction */
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:51:2: error: unknown
      type name 'u8'
        u8  replacementlen;     /* length of new instruction, <= instrlen */
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:164:62: error: unknown
      type name 'size_t'
extern void *text_poke_early(void *addr, const void *opcode, size_t len);
                                                             ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:183:56: error: unknown
      type name 'size_t'
extern void *text_poke(void *addr, const void *opcode, size_t len);
                                                       ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/alternative.h:184:60: error: unknown
      type name 'size_t'
extern void *text_poke_smp(void *addr, const void *opcode, size_t len);
                                                           ^
In file included from /mnt/lfs/sources/linux-2.6.37/init/main.c:13:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/module.h:9:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/list.h:7:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/prefetch.h:14:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/processor.h:17:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/system.h:7:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/cmpxchg.h:4:
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/cmpxchg_64.h:6:39: error: unknown type
      name 'u64'
static inline void set_64bit(volatile u64 *ptr, u64 val)
                                      ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/cmpxchg_64.h:6:49: error: unknown type
      name 'u64'
static inline void set_64bit(volatile u64 *ptr, u64 val)
                                                ^
In file included from /mnt/lfs/sources/linux-2.6.37/init/main.c:13:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/module.h:9:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/list.h:7:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/prefetch.h:14:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/processor.h:17:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/system.h:11:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/irqflags.h:15:
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/irqflags.h:20:2: error: use of
      undeclared identifier 'asm'
        asm volatile("# __raw_save_flags\n\t"
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/irqflags.h:31:2: error: use of
      undeclared identifier 'asm'
        asm volatile("push %0 ; popf"
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/irqflags.h:39:2: error: use of
      undeclared identifier 'asm'
        asm volatile("cli": : :"memory");
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/irqflags.h:44:2: error: use of
      undeclared identifier 'asm'
        asm volatile("sti": : :"memory");
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/irqflags.h:49:2: error: use of
      undeclared identifier 'asm'
        asm volatile("sti; hlt": : :"memory");
        ^
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/irqflags.h:54:2: error: use of
      undeclared identifier 'asm'
        asm volatile("hlt": : :"memory");
        ^
In file included from /mnt/lfs/sources/linux-2.6.37/init/main.c:13:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/module.h:9:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/list.h:7:
In file included from /mnt/lfs/sources/linux-2.6.37/include/linux/prefetch.h:14:
In file included from /mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/processor.h:17:
/mnt/lfs/sources/linux-2.6.37/arch/x86/include/asm/system.h:335:2: error: use of
      undeclared identifier 'asm'
        asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p));
        ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
1 warning and 20 errors generated.

请帮助，我已经尝试谷歌关于这个错误，但没有找到任何适当的。我在内核源代码目录中添加了带有-I标志的内核头文件，因为编译器在我的系统ArchLinux 5.0.10-arch1-1-ARCH上找不到它们。

Answer 1

最后，我在Kamil Cuk的帮助下完成了这项工作。我已经使用了我的.config文件，它是在内核配置期间为编译而生成的。我已经在Vim中打开了它，删除了#-lines和=y，在每行开头添加了#define，并将其保存为内核根目录中的config.h。

clang -emit-ast init/main.c -o astfile -I include -I arch/x86/include -D __EXPORTED_HEADERS__ -D __KERNEL__ -include config.h