FPC feature suggestion
lazarus / 62-General

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440bx · 2018-12-25 06:18

hello,

FPC is very good about issuing hints mentioning the fact that some
variable being used may not have been initialized.  This can be very
useful.

Unfortunately, at this time, there is no way to tell FPC that either,
the variable is already initialized or, that it will be initialized by
the procedure/function it is being passed to.  For instance, consider
the code snippet below:Code: Pascal  [Select][+][-]window.onload =
function(){var x1 = document.getElementById("main_content_section");
if (x1) { var x = document.getElementsByClassName("geshi");for (var i
= 0; i function SomeFunc(parm1 : integer; var parm2 : somerecord) :
Boolean;begin   RtlZeroMemory(@parm2, sizeof(parm2));  // initialize
parm2  { perform binary magic here }  result :=
everything_is_great;end; .........var  MyParm : somerecord; begin  {
use SomeFunc }   r := SomeFunc(v, MyParm);   { compiler issues a hint
that MyParm is not initialized }end. 
It would be very nice to have something along the lines of Code:
Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
{$initializes parm2} that could be placed before SomeFunc's begin
statement to inform the compiler that SomeFunc is responsible for
initializing parm2.  That way, the compiler would not emit superfluous
hints about the variable not being initialized every time SomeFunc is
used in the program's body.

Thanks for reading.

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bytebites · 2018-12-25 08:15

Does this help?
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
SomeFunc(parm1 : integer; out parm2 : somerecord) : Boolean;

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Thaddy · 2018-12-25 08:39

You can suppress the message with {$push}{$warn xxxx off}..
declaration --- {$pop} xxxx is the number of the warning.
Also note rtlxxx fiunctions are platform. Why not Code: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i parm2 :=
Default(SomeRecord);

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ASerge · 2018-12-25 10:28

Quote from: bytebites on December 25, 2018, 09:15:36 amCode: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
SomeFunc(parm1 : integer; out parm2 : somerecord) : Boolean;+1

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440bx · 2018-12-25 11:53

Quote from: bytebites on December 25, 2018, 09:15:36 amDoes this help?
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
SomeFunc(parm1 : integer; out parm2 : somerecord) : Boolean;Not only
that helps, that is the perfect way of doing it.

Thank you, I much appreciate your pointing out the right way of doing
it.