diff options
Diffstat (limited to 'contrib/gcc/doc/frontends.texi')
| -rw-r--r-- | contrib/gcc/doc/frontends.texi | 95 |
1 files changed, 43 insertions, 52 deletions
diff --git a/contrib/gcc/doc/frontends.texi b/contrib/gcc/doc/frontends.texi index 1ee5685..0e4dfe5 100644 --- a/contrib/gcc/doc/frontends.texi +++ b/contrib/gcc/doc/frontends.texi @@ -1,70 +1,61 @@ @c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, -@c 1999, 2000, 2001 Free Software Foundation, Inc. +@c 1999, 2000, 2001, 2004 Free Software Foundation, Inc. @c This is part of the GCC manual. @c For copying conditions, see the file gcc.texi. @node G++ and GCC -@chapter Compile C, C++, Objective-C, Ada, Fortran, Java, or treelang +@chapter Programming Languages Supported by GCC -@cindex Objective-C +@cindex GCC +@cindex GNU Compiler Collection +@cindex GNU C Compiler +@cindex Ada @cindex Fortran @cindex Java -@cindex Ada +@cindex Objective-C @cindex treelang -Several versions of the compiler (C, C++, Objective-C, Ada, -Fortran, Java and treelang) are integrated; this is why we use the name -``GNU Compiler Collection''. GCC can compile programs written in any of these -languages. The Ada, Fortran, Java and treelang compilers are described in -separate manuals. - -@cindex GCC -``GCC'' is a common shorthand term for the GNU Compiler Collection. This is both -the most general name for the compiler, and the name used when the -emphasis is on compiling C programs (as the abbreviation formerly -stood for ``GNU C Compiler''). +GCC stands for ``GNU Compiler Collection''. GCC is an integrated +distribution of compilers for several major programming languages. These +languages currently include C, C++, Objective-C, Java, Fortran, and Ada. + +The abbreviation @dfn{GCC} has multiple meanings in common use. The +current official meaning is ``GNU Compiler Collection'', which refers +generically to the complete suite of tools. The name historically stood +for ``GNU C Compiler'', and this usage is still common when the emphasis +is on compiling C programs. Finally, the name is also used when speaking +of the @dfn{language-independent} component of GCC: code shared among the +compilers for all supported languages. + +The language-independent component of GCC includes the majority of the +optimizers, as well as the ``back ends'' that generate machine code for +various processors. + +@cindex COBOL +@cindex Mercury +@cindex Pascal +The part of a compiler that is specific to a particular language is +called the ``front end''. In addition to the front ends that are +integrated components of GCC, there are several other front ends that +are maintained separately. These support languages such as Pascal, +Mercury, and COBOL. To use these, they must be built together with +GCC proper. @cindex C++ @cindex G++ -When referring to C++ compilation, it is usual to call the compiler -``G++''. Since there is only one compiler, it is also accurate to call -it ``GCC'' no matter what the language context; however, the term -``G++'' is more useful when the emphasis is on compiling C++ programs. - @cindex Ada @cindex GNAT -Similarly, when we talk about Ada compilation, we usually call the -compiler ``GNAT'', for the same reasons. - -We use the name ``GCC'' to refer to the compilation system as a -whole, and more specifically to the language-independent part of the -compiler. For example, we refer to the optimization options as -affecting the behavior of ``GCC'' or sometimes just ``the compiler''. - -Front ends for other languages, such as Mercury and Pascal exist but -have not yet been integrated into GCC@. These front ends, like that for C++, -are built in subdirectories of GCC and link to it. The result is an -integrated compiler that can compile programs written in C, C++, -Objective-C, or any of the languages for which you have installed front -ends. - -In this manual, we only discuss the options for the C, Objective-C, and -C++ compilers and those of the GCC core. Consult the documentation -of the other front ends for the options to use when compiling programs -written in other languages. +Most of the compilers for languages other than C have their own names. +The C++ compiler is G++, the Ada compiler is GNAT, and so on. When we +talk about compiling one of those languages, we might refer to that +compiler by its own name, or as GCC@. Either is correct. @cindex compiler compared to C++ preprocessor @cindex intermediate C version, nonexistent @cindex C intermediate output, nonexistent -G++ is a @emph{compiler}, not merely a preprocessor. G++ builds object -code directly from your C++ program source. There is no intermediate C -version of the program. (By contrast, for example, some other -implementations use a program that generates a C program from your C++ -source.) Avoiding an intermediate C representation of the program means -that you get better object code, and better debugging information. The -GNU debugger, GDB, works with this information in the object code to -give you comprehensive C++ source-level editing capabilities -(@pxref{C,,C and C++,gdb.info, Debugging with GDB}). - -@c FIXME! Someone who knows something about Objective-C ought to put in -@c a paragraph or two about it here, and move the index entry down when -@c there is more to point to than the general mention in the 1st par. +Historically, compilers for many languages, including C++ and Fortran, +have been implemented as ``preprocessors'' which emit another high +level language such as C@. None of the compilers included in GCC are +implemented this way; they all generate machine code directly. This +sort of preprocessor should not be confused with the @dfn{C +preprocessor}, which is an integral feature of the C, C++, and +Objective-C languages. |
