[SOLVED] Derived Type in GFortran

AlexBB · 05-15-2015, 10:58 AM

suicidaleggroll, I now have time to implement your suggestion to get rid of the COMMON blocks. I started with compiling and running the code you posted. Here, I need an explanation about the command line parameters/command options you used. I found one of them here. And that is -fbounds-check which appears to be a deprecated form of -fcheck=bounds, the latter being a new variant.

Code:

$ gfortran -Wall -fbounds-check -c subs.f90
$ gfortran -Wall -fbounds-check main.f90 subs.o

However I could not find -Wall & -c options. What are they?

Your command line options provide a "cleaner" compilation output. When I apply

Code:

gfortran sub_mod.f90

command I get two dozen lines like this"

Code:

/usr/bin/ld: /usr/lib/debug/usr/lib/i386-linux-gnu/crt1.o(.debug_info): relocation 0 has invalid symbol index 11

With your options it just compiles. So, what are the options: -Wall & -c ?

I may have other questions later. Appreciate your help. Thanks, - Alex

suicidaleggroll · 05-18-2015, 10:18 AM

-Wall is short for warn all. From the man page:

Code:

       -Wall
           Enables commonly used warning options pertaining to usage that we
           recommend avoiding and that we believe are easy to avoid.  This
           currently includes -Waliasing, -Wampersand, -Wconversion,
           -Wsurprising, -Wc-binding-type, -Wintrinsics-std, -Wno-tabs,
           -Wintrinsic-shadow, -Wline-truncation, -Wtarget-lifetime,
           -Wreal-q-constant and -Wunused

-c tells it to compile only, and skips the linker. From the man page for gcc (for some reason it's not in the gfortran man page?):

Code:

       -c  Compile or assemble the source files, but do not link.  The linking
           stage simply is not done.  The ultimate output is in the form of an
           object file for each source file.

           By default, the object file name for a source file is made by
           replacing the suffix .c, .i, .s, etc., with .o.

You can't run just:

Code:

gfortran sub_mod.f90

because sub_mod.f90 is not a full program, it's just a module that needs to be linked into a larger program. When you build it with -c it just compiles it and generates the module file required to compile main.f90.

AlexBB · 05-24-2015, 09:14 AM

Thank you, egg roll. I mark this thread as solved. I did simplify my program by removing quite a few COMMON statements. I am now on a roll, <not an egg roll, though :-)> and want to finish the whole project but the time will come for me to clean the whole thing up and I may as well kill other COMMON 's. Thanks for the explanations. - Alex