QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
Dump file does not yield any useful information |
| Ref. No. |
QNX.000009759 |
| Category(ies) |
Development |
| Issue |
When an application compiled with the -g3 (or -g2) option (for debuging information), it crashes with a SIGSEGV and it produces a dump file. When this dump file is used with the Watcom debugger,
x09wd -tr=pmd filename.dmp
it does not yield any debugging information.
What is the explanation?
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| Solution |
The application could potentially be dying in the Watcom libs. Since Watcom does not include any debuging information in the libs, this is probably why the dump file is not showing the source or any other useful information.
First, check the make file of the application, to see if the -g2 or -g3 option is used (-d# is the same as -g#). Without this option in the compiler (linker as well) the debug code is not placed in the application.
An alternative would be to use a map file. More information on using map files is in the Watcom Compiler & Tools manual, in Chapter 9, under "MAP".
Another method that can be used is the stack traces. This can be done from within the Watcom debugger. Once the dump file has been opened, select "Calls" under the "Code" menu. This will show where the code entered into the library.
Occasionally, dump files are corrupt, so try a few dump files to see if this may be the case.
In case all above methods fail, it is necessary to create tracecalls, or place printf statements at the beginning and at the end of each function. Run the application, and wait until it crashes, check the output from the printf's to see what the last function that got started executing was. |
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