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Created page with " There are numerous error messages that the compiler may produce. Most of these relate to errors in the source code (syntax errors of various kinds and so forth) but some repr..."
There are numerous error messages that the compiler may
produce. Most of these relate to errors in the source code
(syntax errors of various kinds and so forth) but some
represent limitations, particularly of memory. The two
passes most likely to be affected by memory limitations are
the code generator and the optimizer. The code generator
will issue the message "No room" if it runs out of dynamic
memory. This can usually be eliminated by simplifying the
expression at the line nominated in the error message. The
more complex the expression, the more memory is required to
store the tree representing it. Reducing the number of sym-
bols used in the program will also help.
Note that this error is different from the message
"Can't generate code for this expression" which indicates
that the expression is in some way too difficult for the
code generator to handle. This message will be encountered
very infrequently, and can be eliminated by changing the
expression in some way, e.g. computing an intermediate value
into a temporary variable.
The optimizer reads the assembler code for a whole
function into memory at one time. Very large functions will
not fit, giving the error message "Optim: out of memory in
_func" where func is the name of the function responsible.
In this case the function should be broken up into smaller
functions. This will only occur with functions with several
hundred lines of C source code. Good coding practice will
normally limit functions to less than 50 lines each.
If a pass exits with the message "Error closing file",
or "Write error on file", this usually indicates that there
is insufficient room on the current disk.
If you use a wordprocessing editor such as Wordstar,
ensure that you use the "non-document" mode or whatever the
corresponding mode is. The edited file should not contain
any characters with the high bit set, and the line feed at
the end of the line must be present. Lines should be not
more than 255 characters long.
When using floating point, ensure that you use a -LF
flag at the END of the command line, to cause the floating
point library to be searched. This will cause floating ver-
sions of printf and scanf to be linked in, as well as
specific floating point routines.
If the non-floating version of printf is used with a
floating format such as %f then it will simply print the
letter f.
If the linker gives an "Undefined symbol" message for
some symbol which you know nothing about, it is possible
that it is a library routine which was not found during the
library search due to incorrect library ordering. In this
case you can search the library twice, e.g. for the stan-
dard library add a -LC to the end of the C command line, or
-LF for the floating library. If you have specified the
library by name simply repeat its name.
