C language target (ANTLR)Edit

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Created , updated

These notes supersede the older notes in "C language target (ANTLR 3.0 prerelease)". Prior to the final release of ANTLR 3.0 there were no examples demonstrating the use of the C language target, but with the final release there are extensive examples which make the older notes redundant.

Installing ANTLR

See "Installing ANTLR 3.0 on Mac OS X Tiger".

Building the C runtime

Given a clean copy of the ANTLR source archive, antlr-3.0.tar.gz:

tar xvzf antlr-3.0.tar.gz
cd antlr-3.0/runtime/C/dist
tar xzvf libantlr3c-3.0.0-rc8.tar.gz
cd libantlr3c-3.0.0-rc8
./configure
make
make check # doesn't do anything yet
sudo make install

Note that although the runtime included with the official 3.0 release is labelled as being 3.0.0-rc8, the changelog seems to indicate that this is indeed the final version of the runtime.

This installs these libraries:

  • /usr/local/lib/libantlr3c.dylib
  • /usr/local/lib/libantlr3c.la
  • /usr/local/lib/libantlr3c.a

And the headers are installed as well:

  • /usr/local/include/antlr3.h (and many others)

Technically, I think it would be more correct if these were installed in /usr/local/lib/antlr/ because there are quite a few of them.

Lexer debugging tricks

Echoing the content of a token

LEXER_RULE : . {printf("\%s\n", GETTEXT()->chars);};

Using gated semantic predicates in lexers

Variables like this cannot be used safely in a multi-threaded context, because the resulting variable is a file-scoped static:

@lexer::members
{
  static ANTLR3_BOOLEAN in_link = ANTLR3_FALSE;
}

Example rule:

INTERNAL_LINK_START: { !in_link }?=> '[[' { in_link = ANTLR3_TRUE; };

To overcome the thread-safety issues you’ll need to allocate your own tracking structure and store a pointer to it in your_lexer->pLexer->rec->userp. For an example, see "Context sensitive lexers".

See also