How To Use Separate Compilation

Table of Contents

Introduction

Using a library

At the command-line, or in Automake.

Using strc at the command-line

  module foo
  imports lib
  strategies
    ...

  module foo
  imports liblib
  strategies
    ...

  strc -i foo.str -la stratego-lib

Using AutoXT and Automake

Libtool, Automake and AutoXT make separate compilation in Makefiles almost trivial.

Use libtool for linking.

• Invoking libtoolize or glibtoolize (MacOS X) in bootstrap
• Add AC_PROG_LIBTOOL to configur.ac

Libtool will add the path of a dynamic library to the search path in the executable. If you don't use Libtool, then you might need to set the LD_LIBRARY_PATH environment variable.

For the separately compiled SSL Makefile.xt defines the variable SSL_LIBS.

All program:

  LDADD += $(SSL_LIBS)

Just for the program foo:

  foo_LDADD = $(SSL_LIBS)

Other libraries: use -L and -l.

Creating your own library

  module mod
  imports liblib
    strategies
      ...

Producing the C code

The Stratego Compiler strc can be used now to generate a library from a module file.str with the command

  strc -i mod.str -c -o libmod.rtee --library 

This produces three files:

• libmod.c
• libmod.str
• libmod.rtree

The first is the C implementation of the closure of mod.str. It provides C functions for all user-defined strategies, and static C functions for strategies generated at compile-time. The last two are the concrete syntax and abstract syntax files for a Stratego module with external definitions for all strategies defined in mod.str and imported modules. It is now possible to import libmod in another Stratego program, instead of mod. Note that libmod.str is produced mainly for documentation, libmod.rtree should be used to import. This is done automatically by the compiler as long as the file is present.

Note that no modules from the 'library' should be imported in the program via another path. This will lead to doubly defined strategies; it is not allowed to extend external definitions.

Compile and link to a library

The C program libmod.c can be compiled to an object file libmod.o and to a static (liblibmod.a) or shared (liblibmod.so) library. This should be done in a makefile; strc does not deal with C compilation of libraries.

Static linking of the libraries thus produced may actually lead to larger executables since no unused-function-removal is performed on the library (for obvious reasons). Shared libraries are the solution here to save diskspace. This can be achieved by proper use of libtool in the buildenvironment; again strc does not provide support for this.

Compiling and linking a library using Libtool and Autmake is very easy. Basically, the only thing you need to do is to declare that you want to have a library:

  pkglib_LTLIBRARIES   = libmod.la 
  pkgdata_DATA         = libmod.rtree

  liblibmod_la_SOURCES = libmod.c
  AM_CPPFLAGS          = -I$(SRTS)/include -I$(ATERM)/include

  libmod.c : 
   $(STRC)/bin/strc -c --library -i ./mod.str -o libmod.rtree

-- MartKolthof - 23 Jun 2005