Databases
StackOverflow2013
Postsdbo
POUnable to see global variable in certain C file, value seems to reset
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POUnable to see global variable in certain C file, value seems to reset
    primarykey
    data
    text
    <p>I have a very frustrating bug that others on the team can't reproduce. I have tried cleaning the project, wiping the directory, pulling from the repository, rebuilding, and even testing in VS 2013.</p> <p>Background: a.c, b.c, c.c and b.inc are all compiled into a DLL (assume they are externed). <code>setfoo()</code> is called first from managed code. So far so good.</p> <p>Later on, <code>testfoo()</code> is called. The global variable is fine, there are no issues. Then <code>testfoo2()</code> is called. This is where things get interesting. I have the memory debugger on with <code>foo's</code> address, and it <strong>will read 4 in memory</strong>. However, if you hover over code in visual studio, it returns 0!. Also, it will output 0. There are many global variables (including <code>FILE</code> handles and they are reset to zero(causing nasty ASSERT failures), ONLY in c.c, but are fine when inspected with the debugger). There are many other x.c modules with that include that have no issues.</p> <p>Ok, now <code>testfoo()</code> is called again. Everything is fine in b.c world. The scary part is that the issue happens on only on my workstation! Any clues on how to debug this?</p> <p>This is from my memory, I believe the code is very close to this skeleton:</p> <p><strong>b.inc</strong></p> <pre><code>int foo; </code></pre> <p><strong>a.c</strong></p> <pre><code>#include &lt;b.inc&gt; void setfoo(){ foo = 4; } </code></pre> <p><strong>b.c</strong></p> <pre><code>#include &lt;b.inc&gt; void testfoo(){ printf(foo); //works } </code></pre> <p><strong>c.c</strong></p> <pre><code>#include &lt;b.inc&gt; void testfoo2(){ printf(foo); //foo is now 0 } </code></pre> <p>To Add: This is very complex, legacy code (think 70s), in a very large company and not much can be changed. There are thousands of variables that would be affected if we start adding extern. Also, I tried extern on one variable, and it still has an issue with that file.</p> <p><strong>I left out one tidbit. 'testfoo2()' launches in a managed thread.</strong> Again, this seems to be related to my machine, could be some setting in visual studio, dunno at this point, we want to just re-image the box. </p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USLen
    1. USLen
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POUnable to see global variable in certain C file, value seems to reset
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POUnable to see global variable in certain C file, value seems to reset
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POUnable to see global variable in certain C file, value seems to reset
      1. This table or related slice is empty.
      1. VTUpMod
    1. COWhy do you use `.inc` (just out of curiosity) when the recommended extension is `.h`
      singulars
      1. POUnable to see global variable in certain C file, value seems to reset
      1. USCole Johnson
    2. COThe code is horribly outdated (probably from the mid 70s) and has to stay :(. extern is not allowed.
      singulars
      1. POUnable to see global variable in certain C file, value seems to reset
      1. USLen
    3. COWhy are you working on a project that disallows `extern`? If I were you, I'd quit. Anyone who thinks `extern` shouldn't be allowed deserves nearly every C program written shoved in their face. As for why you can't change `.inc` to `.h`, it could be done, just may take a while.
      singulars
      1. POUnable to see global variable in certain C file, value seems to reset
      1. USCole Johnson
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload