Debugging in Parallel Studio XE 2011

[Ahmad_Falahatpisheh]

Hi All,

I am debugging my Fortran fixed form code by Parallel Studio XE 2011.

• I have a problem in debugging line by line of my code. I get the following messages in the "immediate window":

First-chance exception at 0x74c5b9bc in Console1.exe: 0xA1A01DB1: 0xa1a01db1.
First-chance exception at 0x00563f69 in Console1.exe: 0xC0000005: Access violation reading location 0x28da0000.
First-chance exception at 0x74c5b9bc in Console1.exe: 0xA1A01DB2: 0xa1a01db2.
First-chance exception at 0x74c5b9bc in Console1.exe: 0xA1A01DB1: 0xa1a01db1.
First-chance exception at 0x74c5b9bc in Console1.exe: 0xA1A01DB1: 0xa1a01db1.
First-chance exception at 0x74c5b9bc in Console1.exe: 0xA1A01DB1: 0xa1a01db1.
First-chance exception at 0x74c5b9bc in Console1.exe: 0xA1A01DB1: 0xa1a01db1.

So when I hit F8 to go to the next line it doesn't go to the next line and instead jumps to another line. Can someone help me what the problem is?

• The second problem that I have is that I cannot view the value of some of my variables in Watch window. Instead of the value of the variable I get "Cannot view register variable". This happens for example when I want to see the loop variable in "Do Loops".

• The IFORT switches are as follows. At first I was using /Qopenmp and I removed it because I thought the "First-chance" exception was caused by /Qopenmp.

/nologo /debug:full /O3 /Qopenmp /warn:interfaces /real_size:64 /module:"Debug\\\\" /object:"Debug\\\\" /traceback /check:bounds /libs:static /threads /dbglibs /c

[IanH · Accepted solution]

You've got full optimisation turned on (the /O3 compiler option). That makes debugging very difficult - the compiler can eliminate variables by keeping results in registers (so you can't easily inspect their values) and can reorder the way things are calculated (so the next statement may not be the next statement), amongst other things.

Why don't you try debugging without optimisation? At the same time I suggest you turn on the full suite of compile time and run time checks. A typical command line might include the switches:

/Od /warn:all /traceback /check:all

or from within Visual Studio under the Fortran project's Fortran property group set:

Optimisation > Optimisation to "Disable"
Diagnostics > Compile Time Diagnostics to "Show All"
Run-time > Generate Traceback Information to "Yes"
Run-time > Runtime Error Checking to "All"

I'd be very tempted to turn off Openmp too, until you are sure that you have a bug free serial version of your code.

Even if your code takes hours (or even days... that's when a spare computer or two is handy...) to run with these settings on it might be quicker to find bugs this way than by working with optimised builds.