HP SunSoft Pascal 4.0 - Manual (Page 240)

216 Pascal 4.0 User’s Guide
9
A statement is considered to be reachable if there is a potential path of control,
even if it cannot be taken. Thus, no diagnostic is produced for the statement:
The goto Statement
Pascal detects and produces an error message about goto statements that
transfer control into structured statements—for example, for and while . It
does not allow such jumps, nor does it allow branching from the then part of
an if statement into the else part. Such checks are made only within the
body of a single procedure or function.
Uninitialized Variables
Pascal does not necessarily set variables to an initial value unless you explicitly
request that with the
–Z option. The exception is static variables, which are
guaranteed to be initialized with zero values.
Because variable use is not tracked across separate compilation units, pc does
nothing about uninitialized or unused variables in global scope, that is, in the
main program. However,
pc checks variables with local scope—those declared
in procedures and functions, to make sure they are initialized before being
used.
pc flags uninitialized variables with a warning message.
Unused Variables, Constants, Types, Labels, and Routines
If you declare a variable, constant, type, procedure, or function in local scope
but never use it, Pascal gives you a warning message. It does not do this for
items declared in global scope because you can use the items in a separately
compiled unit.
This error message is
generated when you compile
unreached.p .
hostname% pc unreached.p
Tue Feb 14 14:21:03 1995 unreached.p:
w 18630 line 8 - Unreachable statement
if false then
writeln('Impossible!')