topic Hello Liying, in Software Archive

reference for gdb-ia

lxh37 — Wed, 13 May 2015 18:32:10 GMT

Hi,

I am new to gdb-ia, wonder if there is reference about how to use it for Fortran in Mac?

Thanks!

Liz

Hello Liz,

Georg_Z_Intel — Mon, 18 May 2015 09:28:46 GMT

Hello Liz,

we do not have a tutorial for using "gdb-ia" as it is not different to any other GNU* GDB (on OS X).

The only things that need to be known:

The compilervars.sh script needs to be sourced first (not only gets you the compiler but also "gdb-ia")
"gdb-ia" and the application to be debugged (debuggee) need to be installed and started on a local drive; no shared/network drives are allowed due to permissions
Depending on the version you have, please refer to the Release Notes (e.g. https://software.intel.com/en-us/articles/intel-parallel-studio-xe-2015-composer-edition-fortran-release-notes)

If you still have problems, please let me know.

Best regards,

Georg Zitzlsberger

lxh37 — Mon, 18 May 2015 14:34:56 GMT

I have created the project in Xcode, turn on Intel Fortran Compiler XE - runtime features
"check array and string bounds", "check for null pointers and allocatable array references,
the program runs without any problem. The memory issue might not be in Fortran code?

Liying

Hello Liying,

Georg_Z_Intel — Mon, 18 May 2015 15:07:02 GMT

Hello Liying,

Using the compiler's checking features is not related to the debugger. The compiler instruments the code to detect common issues at runtime.

It is not guaranteed that its checks are complete. In most cases it can find common mistakes but still can deliver false negatives (i.e. errors are still present but not detected). Using such options can also affect the generated code and hence bugs could be hidden by this (so-called heisenbugs).

Finding such heisenbugs is cumbersome but tools can help (order is my preference):

Intel(R) Fortran Compiler checking features:
Quick and common issues are found fast
Intel(R) Inspector XE:
Requires small setup but finds most issues as long as the heisenbug occurs
Debugging:
Understand was is wrong; requires diligence because debugging changes the behavior of the application

I also recommend to turn off the compiler checking features when debugging (gdb-ia) because they interfere with debuggers. Use them mutually.

Best regards,

Georg Zitzlsberger