Ada问题与STORAGE_ERROR

Question

我有这个小的函数，导致我在RHEL6上头痛，并且我不知道发生了什么......并且这是一个调试的痛苦。当我运行这个时，我得到一个STORAGE_ERROR，所以我做了一个gstack来查看程序挂在哪里（见下文）。它看起来像memcmp的问题，虽然我不知道它在哪里/如何被称为..任何想法的解决方法？

当我改变这个函数返回'真'它似乎工作正常（STORAGE_ERROR消失），所以我认为问题是在这部分的一些逻辑：（Ada.Characters.Handling.To_Upper（ EPS_List（1）.all）=“LOCALHOST”）;

function Localhost_Only return Boolean is 
    --++ 
    EPS_List : String_List_Type 
       := Values(Bstring.To_Bounded_String("EPS")); 
    begin 
    return (Ada.Characters.Handling.To_Upper(EPS_List(1).all) = "LOCALHOST"); 

    end Localhost_Only; 

BEGIN编辑***

另一种方式是workst做这个（移动它的功能范围......为什么这项工作？）：

EPS_List : String_List_Type 
       := Values(Bstring.To_Bounded_String("EPS")); 

    function Localhost_Only return Boolean is 
    --++ 

    begin 
    return (Ada.Characters.Handling.To_Upper(EPS_List(1).all) = "LOCALHOST"); 

    end Localhost_Only; 

END编辑***

gstack输出的过程：

Thread 1 (Thread 0x407059a0 (LWP 13610)): 
#0 0x40000424 in __kernel_vsyscall() 
#1 0x00b2b2fc in pthread_cond_wait@@GLIBC_2.3.2() from /lib/libpthread.so.0 
#2 0x0b53dd9e in system__tasking__stages__vulnerable_complete_master() 
#3 0x0b53e242 in system__tasking__stages__finalize_global_tasks() 
#4 0x0b5845d3 in __gnat_last_chance_handler() 
#5 0x0b545c50 in ada__exceptions__exception_traces__unhandled_exception_terminateXn() 
#6 0x0b5459de in ada__exceptions__exception_propagation__propagate_exceptionXn() 
#7 0x0b5465c5 in __gnat_raise_nodefer_with_msg() 
#8 0x0b5469ed in ada__exceptions__raise_with_location_and_msg() 
#9 0x0b5469b8 in __gnat_raise_storage_error_msg() 
#10 0x0b546f98 in __gnat_rcheck_31() 
#11 0x0b5363de in system__interrupt_management__notify_exception() 
#12 <signal handler called> 
#13 0x0bcef590 in memcmp@@GLIBC_2.0() 
#14 0x084a83c9 in common_network_configuration__localhost_only() 

相关类型/功能：

type Number_Of_Items_Type is range 0 .. 250; 

subtype Index_Type is Number_Of_Items_Type 
    range Number_Of_Items_Type'First + 1 .. Number_Of_Items_Type'Last; 

type String_List_Type is array (Index_Type range <>) 
    of String_Access.String_P_Type; 

package Bstring is new Ada.Strings.Bounded.Generic_Bounded_Length 
          (Max => Line_Length_Type'last); 

    function Values(Name : Bstring.Bounded_String) return String_List_Type is 
    --++ 
    -- ABSTRACT 
    -- Return a list of pointers to strings. The strings are all the values 
    -- associated with the specified name. All values are recursively 
    -- evaluated so that each entry in the returned list is a primitive 
    -- name (i.e. integer, ip_address, or unix_workstation). 
    -- 
    -- If a circular definition is detected, an empty list is returned. 
    -- 
    -- LOCAL DATA 
    -- Number of items in list 
    Count : Number_Of_Items_Type := 0; 

    -- List of pointers to strings containing the primitive values 
    Out_List : String_List_Type (1 .. Index_Type'Last); 

    -- The Index of the item being evaluated 
    Item  : Config_Index_Type := 0; 

    -- A safety net, to detect and prevent unlimited recursion, such as 
    -- will happen in the case of a circular definition. 
    Depth : Number_Of_Items_Type := 0; 

    procedure Find_Values (Name : in Bstring.Bounded_String) is 
    --++ 
    -- ABSTRACT 
    -- This procedure recursively calls itself until it makes it all 
    -- The way through the Config_Array without finding a match on the 
    -- specified Name. The index of the last name for which a match was 
    -- found is used to get the value associated with that Name. This 
    -- is a primitive value associated with the name and is added to the 
    -- Out_List. 
    -- 
    -- Depth is used to count the recursion depth, when it reaches a 
    -- maximum, no more recursive calls are made, preventing an endless 
    -- loop in the case of a direct or indirect circular definition. 
    begin 
     Depth := Depth + 1; 
     for Index in 1 .. Config_Count loop 
     if Name_Match(Bstring.To_String(Name),Index) 
     and Count < Number_Of_Items_Type'last 
     and Depth < Number_Of_Items_Type'last then 
      Item := Index; 
      Find_Values (Config_Array(Index).Value); 
     end if; 
     end loop; 
     if Item /= 0 then 
     if Count < Number_Of_Items_Type'last then 
      Count := Count + 1; 
      Out_List(Count) := Config_Array(Item).Val_Ptr; 
     end if; 
     Item := 0; 
     end if; 
    end Find_Values; 

    begin -- Values 
    Find_Values(Name); 
    if Depth < Number_Of_Items_Type'last then 
     return Out_List(1..Count); 
    else 
     return Null_String_List; 
    end if; 
    end Values; 

Answer 1

解决方案是在RHEL6上升级编译器..

Answer 2

我绝对先在这里猜测是，EPS_List(1)不指向一个有效的内存位置。你检查了吗？

尽我所知，该数组最终从指向Config_Array的指针加载。因此，如果在加载发生时没有初始化它，或者在调用Localhost_Only之前释放这些指针引用的内存，则会出现这种性质的错误。

此代码非常复杂，我只能进入Localhost_Only并检查它。请使用调试器查看这些指针，或在return语句之前添加调试代码以显示其值。

此外，您的Localhost_Only例程接受一个无约束的数组，然后假定它包含元素1。如果没有，我相信你应该得到类似Constraint_Error或Range_Error的东西，但是如果关闭了编译器的范围检查，则可能导致Storage_Error。无论哪种方式，您都应该以某种方式防范这种可能性。喜欢的东西if EPS_List'length > 0 then return False; end if; ...

---

您的编辑，为什么移动的声明防止崩溃我最好的猜测是，这时候在初始化发生变化。它现在发生得更早。同样，它可能会让它回到崩溃状态，并试图找出调试器和/或调试打印语句究竟发生了什么。