[LLVMbugs] [Bug 4390] New: clang: wrong struct initializer

[bugzilla-daemon at cs.uiuc.edu]

http://llvm.org/bugs/show_bug.cgi?id=4390

           Summary: clang: wrong struct initializer
           Product: new-bugs
           Version: unspecified
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: new bugs
        AssignedTo: unassignedbugs at nondot.org
        ReportedBy: edwintorok at gmail.com
                CC: llvmbugs at cs.uiuc.edu
            Blocks: 4068


clang creates this initializer for a struct:
@sysfs_root = global %0 <{ %struct.anon <{ i32 1 }>, %struct.anon
zeroinitializer, %struct.sysfs_dirent* null, %struct.sysfs_dirent* null, i8*
getelementptr ([1 x i8]* @.str, i32 0, i32 0), %union.anon zeroinitializer,
%union.anon zeroinitializer, i8 0, i8 0, i8 0, i8 0, i32 1, i64 1, i8 0, i8 0,
i8 0, i8 0, i8 0, i8 0, i16 16877 }>, align 8         ; <%0*> [#uses=1]

While llvm-gcc creates this initializer for same struct:
@sysfs_root = global %0 { %struct.atomic_t { i32 1 }, [20 x i8]
zeroinitializer, i8* getelementptr ([1 x i8]* @.str, i32 0, i32 0), [16 x i8]
zeroinitializer, i32 1, i64 1, i16 16877, [14 x i8] zeroinitializer }, align 32
          ; <%0*> [#uses=1]

This causes a panic when trying to boot the linux kernel compiled with clang.

Testcase below, when run with clang it aborts, when run
with llvm-gcc or gcc it doesn't:

struct hlist_node {
 struct hlist_node *next, **pprev;
};                                
struct hlist_head {               
 struct hlist_node *first;        
};                                
typedef unsigned short umode_t;   
typedef unsigned long __kernel_ino_t;
typedef __kernel_ino_t ino_t;        
struct sysfs_elem_dir {              
 struct kobject *kobj;               

 struct sysfs_dirent *children;
};                             
struct sysfs_elem_bin_attr {   
 struct bin_attribute *bin_attr;
 struct hlist_head buffers;     
};                              
typedef struct {                
 volatile int counter;          
} atomic_t;                     
struct sysfs_elem_attr {        
 struct attribute *attr;        
 struct sysfs_open_dirent *open;
};                              
struct sysfs_elem_symlink {     
 struct sysfs_dirent *target_sd;
};                              
struct sysfs_dirent {           
 atomic_t s_count;              
 atomic_t s_active;             
 struct sysfs_dirent *s_parent;
 struct sysfs_dirent *s_sibling;
 const char *s_name;

 union {
  struct sysfs_elem_dir s_dir;
  struct sysfs_elem_symlink s_symlink;
  struct sysfs_elem_attr s_attr;
  struct sysfs_elem_bin_attr s_bin_attr;
 };

 unsigned int s_flags;
 ino_t s_ino;
 umode_t s_mode;
 struct iattr *s_iattr;
};
struct sysfs_dirent sysfs_root = {
 .s_name = "",
 .s_count = { (1) },
 .s_flags = 0x0001,
 .s_mode = 0040000 | 00700 | (00400|00040|00004) | (00100|00010|00001),
 .s_ino = 1,
};
struct iattr *foo()
{
    return sysfs_root.s_iattr;
}
umode_t bar()
{
    return sysfs_root.s_mode;
}
int main()
{
    if (foo() || bar() != 16877)
        abort();
}


-- 
Configure bugmail: http://llvm.org/bugs/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.