Compiler usage

Using the C compiler

The two C compilers are described below:

The remainder of this book refers to the cc compiler. Any cc example also applies to the c89 compiler.

The cc compiler command has the form:

% cc [options]files

where

For example, the following command

% cc prog1.c prog2.c prog3.c

compiles the three files (prog1.c, prog2.c, prog3.c) and produces an executable, which is named a.out by default.

In this command,

% cc -o prog prog.c proc1.o

cc compiles prog.c to produce the object file prog.o, then calls the linker ld to link prog.o and proc1.o with the default start-up routines and library routines. The file prog.o is deleted after linking. The -o prog causes the resulting executable file to be named prog instead of a.out.

For additional information, see the cc(1) man page.

Using the Fortran 77 compiler

The two Fortran 77 compilers are described below:

The remainder of this book refers to the f77 compiler. Any f77 example also applies to the fort77 compiler.

The f77 compiler command has the form:

% f77 [options]files

where

For example, the command

% f77 -c prog.f

compiles the file prog.f to produce the object file prog.o, then (because of the -c option) suppresses linking. The prog.o file can be linked later by including it on a f77 command line or by using the linker (ld) directly.

In the following example,

% f77 -v prog1.f prog2.f

the verbose mode is enabled by using -v. When compiling in verbose mode, the compiler displays (to standard error) a step-by-step description of the compilation process.

This command

% f77 +O3 +Oparallel prog.f

shows the request of level 3 optimizations (+O3) and the request that the compiler honor the parallelism directives of the Exemplar programming model and generate parallel code where appropriate (+Oparallel). The +Oparallel option is only valid at +O3 and above.

For additional information, see the f77(1) man page.