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Report From: Delphi-BCB/Compiler/Delphi/Packages [ Add a report in this area ]

Report #: 71588

Status: Open

Global Variable is not initialized to 0

Project: Delphi

Build #: 12.0.3210.17555

Version: 12.1

Submitted By: Serge (Developer Express Support)

Report Type: Basic functionality failure

Date Reported: 2/18/2009 3:41:24 PM

Severity: Infrequently encountered problem

Last Updated: 3/20/2012 2:24:39 AM

Platform: All versions

Internal Tracking #: 268360

Resolution: None (Resolution Comments)

Resolved in Build: : None

Duplicate of: None

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Description

None

Steps to Reproduce:

Run the attached sample and click the button twice.
You'll get an assertion exception, because there is a global variable in Package3 whose value is verified for being zero or not.

Workarounds

None

Attachment

dxSample_B35208.zip

Comments

Serge (Developer Express Support) at 3/4/2009 4:12:25 PM -

Here is the snippet from the "Variables" help topic (ms-help://embarcadero.rs2009/devcommon/variables_xml.html):

If you don't explicitly initialize a global variable, the compiler initializes it to 0. Object instance data (fields) are also initialized to 0. On the Wiin32 platform, the contents of a local variable are undefined until a value is assigned to them.

It seems to contradict your resolution. Could you please comment on this?

Norbert Eggert at 3/21/2009 8:30:35 AM -

That´s wrong! In Delphi2006 the varialbe is 0. In Delphi2009 make the compiler by extended-variables after initialize not zero!. Older programms(2006) compiled with Delphi2009 have now Eoverflow-execpetions. Simple example : var ex : extended begin if ex < 0 then ...

Lutz Ristau at 3/5/2009 8:34:04 AM -

I dont use packages and I dont know the reported problem, but the resolution comment 'by design' is wrong.

The Delphi 6 Help states:
"If you dont explicitly initialize a global variable, the compiler initializes it to 0. Local variables, in contrast, cannot be initialized in their declarations and contain random data until a value is assigned to them."
From all my experience, this statement is true. This the same as all C/C++ compilers do.

Tomohiro Takahashi at 3/5/2009 9:21:19 PM -

I'm looking into the attached projects...
But, I can not build your prjects with compiler error...

Lutz Ristau at 3/6/2009 12:29:20 AM -

Just for information (for the guy who made the "by design" comment): This initialization of global variables is not done by code. Its done by the OS loader, when the data segment for the global variables is created in the process address space. Maybe this is different for packages.

Serge (Developer Express Support) at 4/29/2009 10:05:29 AM -

Any progress on this issue, guys?

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