Many users have come to use with an error during the compile process
using ada on the RISC/System 6000 sites.  This error is usually a
SIG 11 followed by a hex address.  The error is caused by one or more
syntax errors which causes subsequent compiler passes to abort.  The
cause of the errors can be determined by changing the compiler level
option.   (This solution may work as well for the SIG 4 compiler
abort, but has not been tested.)

Before the following can be tried, the user's adalib must be unlocked
(it is usually locked when the compiler aborts).  To unlock your
library enter the following in the directory containing "adalib":

% ada lib.unlock confirm=no

The following ada command syntax will allow you user to determine what
is causing the error (at the system command prompt):

% ada compile \(source=\>my_prog.ada, options=\>\(level=\>parse\)\)

NOTE:  The backslash character is required for c-shell and t-shells,
other shells may require other variations.  If you are unable to get
this command to work within your shell environment, the syntax within
the AdaWorld environment in interactive mode is:

% ada
Ada.compile (source=>myprog.ada, options=>(level=>parse))
Ada.quit

The "options" flag tells the compiler to perform a parse-only pass for
syntax errors.  This will usually result in the syntax errors that are
causing the compiler to abort with the Signal interrupt later.  The
error messages will be contained in the listing file.  Once the errors
have been fixed, the user can try a regular compile again without the
"options" flag.