4.3.5 TC-1 FAQ

Bison reports type clashes

Bison may report type clashes for some actions. For instance, if you have given a type to "string", but none to exp, then it will choke on:

exp: "string";

because, unless you used ‘%define variant’, it actually means

exp: "string" { $$ = $1; };

which is not type consistent. So write this instead:

exp: "string" {};

Where is ast::Exp?

Its real definition will be provided with TC-2, so meanwhile you have to provide a fake. We recommend for a forward declaration of ‘ast::Exp’ in libparse.hh.

Finding prelude.tih

When run, the compiler needs the file prelude.tih that includes the signature of all the primitives. But the executable tc is typically run in two very different contexts:

installed

An installed binary will look for an installed prelude.tih, typically in /usr/local/share/tc/. The cpp macro PKGDATADIR is set to this directory. Its value depends on the use of configure’s option --prefix, defaulting to /usr/local.

compiled, not installed

When compiled, the binary will look for the installed prelude.tih, and of course will fail if it has never been installed. There are two means to address this issue:

The environment variable TC_PKGDATADIR

If set, it overrides the value of PKGDATADIR.

The option --library-prepend/-p

Using this option you may set the library file search path to visit the given directory before the built-in default value. For instance ‘tc -p /tmp foo.tig’ will first look for prelude.tih in /tmp.

Must import be functional?

Yes. Read the previous item.