Databases
StackOverflow2013
Postsdbo
POc++ double delete of files scope variable, linking issue?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POc++ double delete of files scope variable, linking issue?
    primarykey
    data
    text
    <p>I am on RHEL 6 with gcc version 4.1.2.</p> <p>I am facing exact same problem as described in this post. Only difference is I am facing this problem for file scope variable. (The variable declared outside the class but in the file, so that it case be accessible across two to three functions. And this variable is getting double deleted even if I have declared on stack)</p> <p><a href="https://stackoverflow.com/questions/6714046/c-linux-double-destruction-of-static-variable-linking-symbols-overlap">c++ linux double destruction of static variable. linking symbols overlap</a></p> <p>In my application, I have similar situation.</p> <pre><code>static library "slib" -- inside this library, there is static object "sobj" dynamic library "dlib" -- links staticly "slib" executable "exe": -- links "slib" staticly -- links "dlib" dynamicly </code></pre> <p>I suspect, I am also facing same problem. To verify, I need to come up with g++ command which will build the files in above manner. I have tried executing following commands but it does not reproduce the said behavior. </p> <pre><code>g++ -Wall -c static_lib.cpp ar -cvq libtests.a static_lib.o g++ -Wall -fPIC -c dynamic_lib.cpp g++ -shared -Wl,-soname,libtestd.so.1 -o libtestd.so.1.0 dynamic_lib.o -L. libtests.a ln -s libtestd.so.1.0 libtestd.so g++ -Wall -I. -L. main_exe.cpp -ltestd -ltests -o main_prog </code></pre> <p>I am not sure If I have linked the files correctly or in required mannger. But It is not producing the defect which I want to observe. For example, my version of executable outputs following data.</p> <pre><code>user:~/problem$ ./main_prog CTest() this=134520880 use use ~CTest() this=134520880, is Alive </code></pre> <p>Where as make file generated using cmake, outputs following data.</p> <pre><code>user:~/problem$ ./main_exe CTest() this=134520880 CTest() this=134520880 use use ~CTest() this=134520880, is Alive ~CTest() this=134520880, is Dead </code></pre> <p>Could you please help to achieve the same effect. I have tried running makefile -n to print commands but it does not print all commands and stops after building dynamic library. </p> <p>Any inputs will be apprciated. Update: I used 'make VERBOSE=1' and observed followed commands to get executed. I don't know why -rdynamic is used but We use the same in our application. Please find commands getting executed below.</p> <pre><code>/usr/bin/c++ -fPIC -c static_lib.cpp /usr/bin/ar cr libstatic_lib.a static_lib.o /usr/bin/ranlib libstatic_lib.a /usr/bin/c++ -fPIC -c dynamic_lib.cpp /usr/bin/c++ -fPIC -shared -Wl,-soname,libdynamic_lib.so -o libdynamic_lib.so dynamic_lib.o libstatic_lib.a /usr/bin/c++ -fPIC -c main_exe.cpp /usr/bin/c++ main_exe.o -o main_exe -rdynamic libstatic_lib.a libdynamic_lib.so -Wl,-rpath,/home/amey/c_examples/cmake </code></pre> <p>Additionally, nm tests revealed that symbol has different values.</p> <pre><code>desktop:~/c_examples/cmake$ nm libdynamic_lib.so |grep _ZN5CTest4testE 0000000000201048 B _ZN5CTest4testE desktop:~/c_examples/cmake$ nm main_exe |grep _ZN5CTest4testE 0000000000602048 B _ZN5CTest4testE desktop:~/c_examples/cmake$ nm libstatic_lib.a |grep _ZN5CTest4testE 0000000000000000 B _ZN5CTest4testE </code></pre> <p>So two major questions are hauling in my head? 1) Why there are two constructors? Even if there are two constructors why they are pointing to same object 2) Is there any compilation sequence problem?</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USCommunity
    1. USAmey Jah
    plurals
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COAre you (via `cmake`) using any linker options to ignore duplicate definitions? Because that's the only way you'd get double calls to the constructor and destructor.
      singulars
      1. POc++ double delete of files scope variable, linking issue?
      1. USBen Voigt
    2. COHi Ben, I am not familiar with cmake at all. I am using CMakeLists.txt mentioned in my link post
      singulars
      1. POc++ double delete of files scope variable, linking issue?
      1. USAmey Jah
 

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