C++ compilation - crash - gdb debugging - pvm
As you have noticed in class, a computer is not perfect and not
enough to understand all your needs...
That's why we constructed this page!
This page will be updated regularly, if you still have problems, contact me, so we can add it to this page!!
Try to report the problem (what is the problem, error messages, ...) as exact as possible
|warning: clock skew detected...||this is no real problem, don't worry|
|warning: implicit declaration of function xxx (compilation)||the header file where this function is declared, is not
or you mistyped the functions name
|cannot find function at link time||be sure the file in the header and c-file or exactly the same|
|"multiple definitions of ..."||compiler or linker found 2 times the same function:
- or you reimplemented an existing function
- or you linked the same object file multiple times
|linking of libraries||when a library is using another, the link order is important!! If lib2 is using lib1, you should link in this order: -llib2 -llib1|
|program crashes for big problem
||the sizes of static arrays (eg: int arr) are limited!
Use dynamic arrays (arr = new
|link error "undefined reference
to vtable for class x"
||your class is not complete (not
all methods are implemented...)
put each qt QObject class (widgets etc) in a separate file!
with qt signals & slots, you sometimes need to compile it a second time (so that the moc file is generated)
|problems with templates||read this important comment|
|crash with a glibc error
while using PAPI or our PAPIprofiler
|Don't put your code in a
directory with a name containing spaces
|while debugging, gdb stops
Program received signal SIG32, Real-time event 32
|execute handle SIG32 pass noprint nostop
to ignore these stops
|can't find file (when trying to put a breakpoint)||the -g compile flag must be set (makefile) or debug for the tmake CONFIG|
|Warning: source file is more recent than executable||it means that you should recompile the executable!|
|failed to add machine to pvm||the computer you are working on should be added to .rhosts file|
|problems adding machines on infopc4||the pvm of infopc4 got a lot of errors...
run your program on a different computer, eg infopc23 with rsh infopc23 (do this for the 3 consoles)