本机 localtime() 段错误

Question

在尝试在 Perl 6 中公开 localtime 功能时，我似乎做错了：

use NativeCall;
my class TimeStruct is repr<CStruct> {
    has int32 $!tm_sec;
    has int32 $!tm_min;
    has int32 $!tm_hour;
    has int32 $!tm_mday;
    has int32 $!tm_mon;
    has int32 $!tm_year;
    has int32 $!tm_wday;
    has int32 $!tm_yday;
    has int32 $!tm_isdst;
    has Str   $!tm_zone;
    has long  $!tm_gmtoff;
}

sub localtime(uint32 $epoch --> TimeStruct) is native {*}
dd localtime(time);  # segfault

在perl6-lldb-m下运行，我得到：

Process 82758 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x5ae5dda1)
    frame #0: 0x00007fffe852efb4 libsystem_c.dylib`_st_localsub + 13
libsystem_c.dylib`_st_localsub:
->  0x7fffe852efb4 <+13>: movq   (%rdi), %rax
    0x7fffe852efb7 <+16>: movq   %rax, -0x20(%rbp)
    0x7fffe852efbb <+20>: movq   0x8e71d3e(%rip), %rbx     ; lclptr
    0x7fffe852efc2 <+27>: testq  %rbx, %rbx
Target 0: (moar) stopped.

我在这里做错了什么明显的事情吗？

更新：最终的工作解决方案：

class TimeStruct is repr<CStruct> {
    has int32 $.tm_sec;    # *must* be public attributes
    has int32 $.tm_min;
    has int32 $.tm_hour;
    has int32 $.tm_mday;
    has int32 $.tm_mon;
    has int32 $.tm_year;
    has int32 $.tm_wday;
    has int32 $.tm_yday;
    has int32 $.tm_isdst;
    has long  $.tm_gmtoff; # these two were
    has Str   $.time_zone; # in the wrong order
}

sub localtime(int64 $epoch is rw --> TimeStruct) is native {*}

my int64 $epoch = time;  # needs a separate definition somehow
dd localtime($epoch);

Answer 1

localtime() 需要一个 time_t* 类型的指针作为参数。假设 time_t 和 uint32_t 在您的特定平台上是兼容的类型，

sub localtime(uint32 $epoch is rw --> TimeStruct) is native {*}
my uint32 $t = time;
dd localtime($t);

应该这样做（尽管除非你公开你的属性，否则你什么都看不到）。

我有点惊讶您的time_t 不是 64 位类型，并且刚刚搜索了apple time.h，我还怀疑您的结构声明中的最后两个属性的顺序错误...