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@c Copyright (C) 2002 Free Software Foundation, Inc.

@c This is part of the GCC manual.

@c For copying conditions, see the file gcc.texi.

@node Languages

@chapter Language Front Ends in GCC

The interface to front ends for languages in GCC, and in particular

the @code{tree} structure (@pxref{Trees}), was initially designed for

C, and many aspects of it are still somewhat biased towards C and

C-like languages.  It is, however, reasonably well suited to other

procedural languages, and front ends for many such languages have been

written for GCC@.

Writing a compiler as a front end for GCC, rather than compiling

directly to assembler or generating C code which is then compiled by

GCC, has several advantages:

@itemize @bullet

@item GCC front ends benefit from the support for many different

target machines already present in GCC@.

@item GCC front ends benefit from all the optimizations in GCC@.  Some

of these, such as alias analysis, may work better when GCC is

compiling directly from source code then when it is compiling from

generated C code.

@item Better debugging information is generated when compiling

directly from source code than when going via intermediate generated C

code.

@end itemize

Because of the advantages of writing a compiler as a GCC front end,

GCC front ends have also been created for languages very different

from those for which GCC was designed, such as the declarative

logic/functional language Mercury.  For these reasons, it may also be

useful to implement compilers created for specialized purposes (for

example, as part of a research project) as GCC front ends.