z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

It provides information about exactly which compiler, prelinker, and link
editor options are being passed, and also which data sets are being used. If
you want to obtain this information without actually invoking the underlying
programs, specify the -v option more than once on the c89/cc/c++
command string. For more information about the programs which are
executed, see Usage Note 14 on page 101.
-W phase, option[,option]...
Specifies options to be passed to the steps associated with the compile,
assemble, or link-editing phases of c89/cc/c++. The valid phase codes are:
0 Specifies the compile phase (used for both non-IPA and IPA
compilation).
a Specifies the assemble phase.
c Same as phase code 0.
I Enables IPA (Interprocedural Analysis) optimization.
Unlike other phase codes, the IPA phase code I does not require
that any additional options be specified, but it does allow them. In
order to pass IPA suboptions, specify those suboptions using the
IPA phase code.
Example: To specify that an IPA Compile should save source line
number information, without writing a listing file, specify:
c89 -c -W I,list file.c
Example: To specify that an IPA Link-edit should write the map file
to stdout, specify:
c89 -W I,map file.o
l Specifies the link-editing phase.
v To pass options to the prelinker, the first link-editing phase option
must be p or P. All the following options are then prelink options.
Example: To write the prelink map to stdout, specify:
c89 –W l,p,map file.c
Note: The prelinker is no longer used in the link-editing phase in
most circumstances. If it is not used, any options passed
are accepted but ignored. See the environment variable
prefix_STEPS under “Environment variables” on page 84
for more information about the link-editing phase prelink
step.
v To pass options to the IPA linker, the first link-editing phase
option must be i or I. All the following options are then IPA Link
options.
Example: To specify the size of the SPILL area to be used
during an IPA Link-edit, you could specify:
c89 –W l,I,"spill(256)" file.o
v To link-edit a DLL (Dynamic Link Library) and produce a side
deck, the link-editing phase option DLL must be specified.
Example: To accomplish this task, you could specify:
c89 –o outdll –W l,dll file.o
c89, cc, and c++
Most z/OS XL C/C++ extensions can be enabled by using this option.
Those which do not directly pass options through to the underlying steps, or
involve files which are extensions to the compile and link-edit model, are
described here:
Chapter 2. Shell command descriptions 77