On Mon, Mar 21, 2016 at 8:40 PM, Scott Doctor <scott at scottdoctor.com> wrote:
> you are missing
>
> using System;
whatever. It still fails because it says the variable is
uninitilalized. THe only thing that doesn't is actually running it.
That same pattern not matter what the language triggers warning/error checkers
>
> ------------
> Scott Doctor
> scott at scottdoctor.com
> ------------------
>
>
> On 3/21/2016 5:21 PM, J Decker wrote:
>>
>> So far I just see analysis tools fail for the same sorts of valid code...
>>
>> this is a bit of C# but the same idea causes the same warnings and
>> there's nothign tecniclally wrong with this.
>>
>>
>>
>> class test
>> {
>> struct large_struct { public int x; }
>> bool arbitrary_true_false = true;
>> void method()
>> {
>> bool initialized = false;
>> large_struct s;
>> if( arbitrary_true_false )
>> {
>> initialized = true;
>> s.x = 1;
>> }
>> if( initialized )
>> {
>> Console.WriteLine( "this fails(during compile) as
>> uninitialized: {0}", s.x );
>> }
>> }
>> }
>>
>> On Mon, Mar 21, 2016 at 4:35 PM, James K. Lowden
>> <jklowden at schemamania.org> wrote:
>>>
>>> On Mon, 21 Mar 2016 13:48:06 -0700
>>> Scott Perry <numist at apple.com> wrote:
>>>
>>>> Compilers allow you to choose your standard; --std=c11 means
>>>> something very specific (and unchanging)
>>>
>>> They do. And that covers what the standard covers. The standard also
>>> has limits. It includes constructs that are syntactically permitted
>>> but whose behavior is left undefined, known by the scarred as "UB" for
>>> "undefined behavior". An example from Clang's discussion is
>>>
>>> int i = 10 << 31;
>>>
>>> The standard says << is a shift operator. It places no limit on the
>>> number of bits to be shifted. If that number is so large that the
>>> product cannot be represented by the assigned variable, that is *not*
>>> an error. The standard allows the compiler to do anything or nothing
>>> with it. As you may imagine, the varieties of anything and nothing are
>>> many.
>>>
>>> Compiler writers are well aware that "nothing" is faster done than
>>> "something". Over time, they have gotten more aggressive in simply
>>> deleting UB code. As a consequence, programmers who thought they wrote
>>> standards-conforming code get burned when they upgrade/change
>>> compilers. Mysterious and sometimes subtle errors are introduced by
>>> the compiler for the user's benefit.
>>>
>>> Your googlefu will turn up lots of discussion. One I liked that wasn't
>>> on Page 1:
>>>
>>>
>>> http://blog.frama-c.com/index.php?post/2013/10/09/Overflow-float-integer
>>>
>>> --jkl
>>> _______________________________________________
>>> sqlite-users mailing list
>>> sqlite-users at mailinglists.sqlite.org
>>> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>
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>
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