unique

Syntax

-qunique | -qnounique

Purpose
Generates unique names for static constructor/deconstructor file compilation units.

Notes
Unique names are generated with -qunique by encoding random numbers into thename of the static initialization (sinit) and static termination (sterm) functions. Default behavior is encoding the absolute path name of the source file in the sinit and sterm functions. If the absolute path name will be identical for multiple compilations (for example, if a make script is used), the -qunique option is necessary.

Using -qnounique allows you to do incremental linking of files.

If you use -qunique, you must always link with all .o and .a files. Do not include an executable file on the link step. An object (.o) file compiled with -qunique should not be used for incremental linking.

Example
Suppose you want to compile several files using the same path name, ensuring that static construction works correctly. A make file may generate the following steps:

sqlpreprocess file1.sql > t.C
  xlC -qunique t.C -o file1.o
rm -f t.C
sqlpreprocess file2.sql > t.C
  xlC -qunique t.C -o file2.o
rm -f t.C
  xlC file1.o file2.o

Following is a sample make file for the above example:

# rule to get from file.sql to file.o
.SUFFIXES:      .sql
.sql.o: 
       sqlpreprocess $< > t.C
       $(CCC) t.C -c $(CCFLAGS) -o $@
       rm -f t.C

List of Compiler Options and Their Defaults