llvm-3.4.2 编译失败 解决方案

编译时报错如下:

In file included from $HOME/opt/workspace/doris/incubator-doris/thirdparty/src/llvm-3.4.2.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc:196:0:
$HOME/opt/workspace/doris/incubator-doris/thirdparty/src/llvm-3.4.2.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h:307:72: error: size of array 'assertion_failed__1093' is negative
     typedef char IMPL_PASTE(assertion_failed_##_, line)[2*(int)(pred)-1]
                                                                        ^
$HOME/opt/workspace/doris/incubator-doris/thirdparty/src/llvm-3.4.2.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h:301:30: note: in expansion of macro 'IMPL_COMPILER_ASSERT'
 #define COMPILER_CHECK(pred) IMPL_COMPILER_ASSERT(pred, __LINE__)
                              ^~~~~~~~~~~~~~~~~~~~
$HOME/opt/workspace/doris/incubator-doris/thirdparty/src/llvm-3.4.2.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h:1472:3: note: in expansion of macro 'COMPILER_CHECK'
   COMPILER_CHECK(sizeof(__sanitizer_##TYPE) == sizeof(TYPE))
   ^~~~~~~~~~~~~~
$HOME/opt/workspace/doris/incubator-doris/thirdparty/src/llvm-3.4.2.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc:1093:1: note: in expansion of macro 'CHECK_TYPE_SIZE'
 CHECK_TYPE_SIZE(__kernel_fd_set);

看上去似乎是有点静态检查失败了。

看一下__kernel_fd_set的定义:$GCCHOME/include/linux/posix_types.h

#undef __NFDBITS
#define __NFDBITS   (8 * sizeof(unsigned long))

#undef __FD_SETSIZE
#define __FD_SETSIZE    51200

#undef __FDSET_LONGS
#define __FDSET_LONGS   (__FD_SETSIZE/__NFDBITS)

#undef __FDELT
#define __FDELT(d)  ((d) / __NFDBITS)

#undef __FDMASK
#define __FDMASK(d) (1UL << ((d) % __NFDBITS))

typedef struct {
    unsigned long fds_bits [__FDSET_LONGS];
} __kernel_fd_set;

果然最大fd数量是 51200

在能编译过的机器(ubuntu 18.04)上这个值是: 1024

#undef __FD_SETSIZE
#define __FD_SETSIZE    1024

typedef struct {
    unsigned long fds_bits[__FD_SETSIZE / (8 * sizeof(long))];
} __kernel_fd_set;

然后修改一下__sanitizer___kernel_fd_set

typedef struct {
	unsigned long fds_bits[1024 / (8 * sizeof(long))];
} __sanitizer___kernel_fd_set;

改好之后，就能编译了