Indentation fix, cleanup.

[AROS.git] / tools / fd2inline / fd2inline.texi

\input texinfo.tex  @c -*-texinfo-*-
@c %**start of header
@setfilename fd2inline.info
@settitle FD2InLine User's Guide
@set lastupdate March 22nd, 1998
@include version.texi
@c %**end of header

@dircategory GeekGadgets programming tools
@direntry
* FD2Inline: (fd2inline).        Creates @samp{GNU CC} @samp{inlines}.
@end direntry
                              
@ifinfo
This is a user's guide to FD2Inline @value{version}, a parser
converting FD files to GCC ``inlines''.

Copyright @copyright{} 1996, 1997, 1998 Kamil Iskra
Copyright @copyright{} 1999 - 2003 Martin Blom
Copyright @copyritht{} 2010 AROS development team

Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
@end ifinfo

@titlepage
@sp 10
@center @titlefont{FD2InLine}
@subtitle User's Guide to FD2InLine parser
@subtitle @value{lastupdate}
@author Kamil Iskra
@page
@end titlepage

@ifinfo
@node Top, Introduction, (dir), (dir)
This is a user's guide to @samp{FD2Inline} @value{version}, a parser
that converts the AmigaOS and p.OS shared library @samp{FD} files to
format accepted by the @samp{GNU CC}.

See file @file{COPYING} for the GNU General Public License.

Last updated @value{lastupdate}.
@end ifinfo

@menu
* Introduction::  What is this program for?
* Installation::  How to install it?
* Usage::         How to use @samp{inlines} and @samp{FD2InLine}?
* Rebuilding::    How to recompile it?
* Internals::     How do @samp{inlines} work?
* History::       What has changed?
* Authors::       Who wrote it?

* Index::         Concept index.
@end menu

@node Introduction, Installation, Top, Top
@chapter Introduction
@cindex Introduction
@cindex What FD2InLine is

@samp{FD2InLine} is useful if you want to use @samp{GCC} for AmigaOS
and p.OS specific development and would like to call the functions in
the shared libraries efficiently.

The format of calls to the AmigaOS shared library functions differs
substantially from the default function call format of C compilers
(@pxref{Background}). Therefore, some tricks are necessary if you want
to use these functions.

The format of calls used in the current development versions of p.OS
is much more similar to the call format of C compilers
(@pxref{Internals}), nevertheless some tricks are still necessary.

@samp{FD2InLine} is a parser that converts @samp{fd} files and
@samp{clib} files to @samp{GCC inlines}.

@samp{fd} and @samp{clib} files contain information about functions in
shared libraries (@pxref{Background}).

@samp{FD2InLine} reads these two files and merges the information
contained therein, producing an output file suitable for use with the
@samp{GCC} compiler.

This output file contains so-called @dfn{inlines} --- one for each
function entry. Using them, @samp{GCC} can produce very efficient code
for making function calls to the AmigaOS and p.OS shared libraries.

@quotation
@emph{Note:} the term @samp{inlines} is misleading ---
@samp{FD2InLine} no longer uses the @code{__inline} feature of
@samp{GCC} (@pxref{New format}).
@end quotation

@node Installation, Usage, Introduction, Top
@chapter Installation
@cindex Installation
@cindex Where to put it

The following assumes you have the
@file{fd2inline-@value{version}-bin.lha} archive.

If you use a recent release of @samp{GCC}, you might not need to
install anything. Starting with @samp{GCC} 2.7.2, the new format
(@pxref{New format}) of @samp{inlines} should be available with the
compiler. However, the separate
@file{fd2inline-@value{version}-bin.lha} archive will always contain
the latest version of @samp{FD2InLine} and the @samp{inlines}, which
might not be the true for the @samp{GeekGadgets} or @samp{Aminet}
distributions. @samp{GeekGadgets} distribution might not contain some
of the supported 3rd party libraries' @samp{inlines}.

The installation is very easy, so there is no Installer script :-).

If you have an older version of the @samp{inlines} installed, please
remove it now, or you might encounter problems later. Typically, you
will have to remove the following subdirectories of the
@file{os-include} directory: @file{inline}, @file{pragmas} and
@file{proto}.

Next, please change your current directory to @file{GG:} (or
@file{ADE:} or @file{GNU:}, if you use older distributions) and simply
unpack the @file{fd2inline-@value{version}-bin.lha} archive. This
should install everything in the right place. More precisely, the
headers will go to the @file{include} directory, the libraries to
@file{lib}, @file{fd2inline} executable to @file{bin} directory and
the @samp{AmigaGuide} documentation to the @file{guide} directory.

@node Usage, Rebuilding, Installation, Top
@chapter Usage
@cindex Usage

This chapter describes two aspects of using @samp{FD2InLine}:

@menu
* Using inlines::    Making efficient function calls.
* Using fd2inline::  Creating @samp{inlines}.
@end menu

@node Using inlines, Using fd2inline, Usage, Usage
@section Using inlines
@cindex Using inlines
@cindex Making efficient calls

@menu
* Using inlines under AmigaOS::
* Using inlines under p.OS::
@end menu

@node Using inlines under AmigaOS, Using inlines under p.OS, Using inlines, Using inlines
@subsection Using inlines under AmigaOS
@cindex Using inlines under AmigaOS

Using @samp{inlines} under AmigaOS is very simple. If you want to use
a library called @samp{foo.library} (or a device called
@samp{bar.device}), simply include file @samp{<proto/foo.h>}
(@samp{<proto/bar.h>}) and that's it. For example:

@example
#include <proto/dos.h>

int main(void)
@{
   Delay(100); /* Wait for 2 seconds */
@}
@end example

Please @emph{always} include @file{proto} files, @emph{not}
@file{inline} files --- @file{proto} files often fix some
incompatibilities between system headers and @samp{GCC}. Besides, this
technique makes your code more portable across various AmigaOS
@samp{C} compilers.

@cindex Preprocessor symbols under AmigaOS
There are a few preprocessor symbols which alter the behaviour of the
@samp{proto} and @samp{inline} files:

@table @code
@item __NOLIBBASE__
By default, the @samp{proto} files make external declarations of the
library base pointers. You can disable this behaviour by defining
@code{__NOLIBBASE__} before including a @samp{proto} file.

@cindex __CONSTLIBBASEDECL__
@item __CONSTLIBBASEDECL__
The external declarations described above declare plain pointer
variables. The disadvantage of this is that the library base variable
has to be reloaded every time some function is called. If you define
@code{__CONSTLIBBASEDECL__} to @code{const}, less reloading will be
necessary, and better code will be produced. However, declaring a
variable as @code{const} makes altering it impossible, so some dirty
hacks are necessary (like defining the variable as plain in one file
and altering it only there. However, this will @emph{not} work with
base relative code).

@cindex <library>_BASE_NAME
@item <library>_BASE_NAME
Function definitions in the @samp{inline} files refer to the library
base variable through the @code{<library>_BASE_NAME} symbol (e.g.,
@code{AMIGAGUIDE_BASE_NAME} for @samp{amigaguide.library}). At the top
of the @samp{inline} file, this symbol is redefined to the appropriate
library base variable name (e.g., @code{AmigaGuideBase}),
@emph{unless} it has been already defined. This way, you can make the
@samp{inlines} use a field of a structure as a library base, for
example.

@item NO_INLINE_STDARG
This symbol prevents the definition of inline macros for varargs
functions (@pxref{Old format}).

@cindex _USEOLDEXEC_
@item _USEOLDEXEC_
This symbol is used only in @file{proto/exec.h}. Unlike @samp{SAS/C},
@file{proto/exec.h} uses the @code{SysBase} variable as the
@samp{Exec} library base by default. This is usually faster than
direct dereferencing of @code{0x00000004} (@pxref{Background}), since
it does not require reading from @samp{CHIP} memory (things might be
even worse if you use @samp{Enforcer} or @samp{CyberGuard}, which
protect the low memory region). However, in some low-level cases (like
startup code) you might prefer dereferencing @code{0x00000004}. To do
this, define @code{_USEOLDEXEC_} before including @file{proto/exec.h}.

@cindex __CLIB_TYPES__
@item __CLIB_TYPES__
By default, the @samp{stub} files just include the file
@file{inline/stubs.h>}, which defines some basic types and forward
declares a bunch of structures.  This works for most libraries, but it
is not enough some third party libraries and some libraries distributed
with AmigaOS 3.5 and later. If you define @code{__CLIB_TYPES__}, some
definitions from the clib file will be activated.
@end table

@node Using inlines under p.OS, , Using inlines under AmigaOS, Using inlines
@subsection Using inlines under p.OS
@cindex Using inlines under p.OS

Using @samp{inlines} under p.OS is just as simple as under AmigaOS.
The equivalent of the source presented in the previous section
(@pxref{Using inlines under AmigaOS}) would look like this:

@example
#include <pclib/pDos_protos.h>

int main(void)
@{
   pOS_DosDelay(100); /* Wait for 2 seconds */
@}
@end example

One significant difference is that one should @emph{always} include
@file{pclib} files, not @file{pProto} files --- just opposite to
AmigaOS.

@cindex Preprocessor symbols under p.OS
There are two preprocessor symbols which alter the behaviour of the
@samp{pInline} files:

@table @code
@cindex __<library>_BASE_NAME
@item __<library>_BASE_NAME
Function definitions in the @samp{pInline} files refer to the library
base variable through the @code{__<library>_BASE_NAME} symbol (e.g.,
@code{__INTUI_BASE_NAME} for @samp{pintui.library}). At the top of the
@samp{pInline} file, this symbol is redefined to the appropriate
library base variable name (e.g., @code{gb_IntuiBase}), @emph{unless}
it has been already defined. This way, you can make the @samp{inlines}
use a field of a structure as a library base, for example.

@cindex __<library>_LIB_NAME
@item __<library>_LIB_NAME
This symbol is defined in the same way as the previous one, and it
serves similar purpose. @xref{p.OS format}, for more information.
@end table

@node Using fd2inline, , Using inlines, Usage
@section Using fd2inline
@cindex Using FD2Inline
@cindex Creating inlines

You invoke @samp{FD2InLine} by writing:

@example
@file{fd2inline} [options] @var{fd-file} @var{clib-file} [[-o] @var{output-file}]
@end example

The command line arguments have the following meaning:

@table @var
@item fd-file
The name of the input @samp{fd} file.

@item clib-file
The name of the input @samp{clib} file.

@item output-file
The name of the output @samp{inline} or @samp{proto}file. If it is not
specified (or if @samp{-} is specified), standard output will be used
instead. The file name can be preceded by a @samp{-o}, for
compatibility with most @samp{UN*X} software.
@end table

The following options can be specified (anywhere on the command line):

@table @samp
@item --new
Produce new format @samp{inlines}.

@item --old
Produce old format @samp{inlines}.

@item --stubs
Produce library stubs.

@item --proto
Produce @samp{proto} file. If this option is specified, providing
@samp{clib} file is not necessary. @samp{fd2inline} will only read
@samp{fd} file and will generate a @samp{proto} file, to be put in
@file{include/proto} directory.

@item --pos
Produce p.OS @samp{inlines}. This flag is now obsolete. Use the
@samp{--target} option instead.

@item --target=TARGET
Produce @samp{inlines} for the given target. Valid targets are:
@samp{m68k-amigaos}, @samp{m68k-pos}, @samp{ppc-powerup}
and @samp{ppc-morphos}.

@item --version
Print version information and exit.
@end table

@xref{Internals}, for more information.

Example:

@example
fd2inline GG:os-lib/fd/exec_lib.fd GG:os-include/clib/exec_protos.h -o GG:include/inline/exec.h
@end example

This will build file @file{exec.h} containing new format
@samp{inlines} of @samp{exec.library} in directory
@file{GG:include/inline}.

If you want to add support for @samp{GCC} to an AmigaOS library, there
are a few things you should remember about.

Sometimes, @samp{FD2InLine} might not know how to handle a function
found in a @samp{clib} file, if this function doesn't have a
corresponding entry in the @samp{fd} file. This is most often a case
of @samp{varargs} functions (@pxref{Background}), if they use
nonstandard naming convention. @samp{FD2InLine} will warn you if it
finds such a function. There is an array of such exceptions in
@samp{FD2InLine} source code. You should add the name of this function
there and send a patch to @samp{FD2InLine} maintainer
(@pxref{Authors}), for inclussion in the next release of
@samp{FD2InLine}.

@samp{FD2InLine} assumes that the type of the base variable is
@code{struct Library *}. If it is something different in your case,
you should extend an array of exceptions in @samp{FD2InLine} source
code (see above).

@samp{FD2InLine} handles @code{void} functions in a special way. It
recognizes them by the return value --- it has to be @code{void} (the
case is not significant). If a @samp{clib} file uses a different
convention, it has to be modified before running @samp{FD2InLine}.

In addition to creating @samp{inlines} you must also create a
@samp{proto} file.

The easiest way to do it is to call @samp{FD2InLine} with
@samp{--proto} option. Most often, the generated file will be ready to
use. Unfortunately, some libraries (like, for example,
@samp{dos.library}) have broken header files and @samp{GCC} generates
warning messages if you try to use them. To avoid these warnings, you
have to include various headers in the @samp{proto} file before
including the @samp{clib} file.

You might also want to create a @samp{pragmas} file, which might be
necessary for badly written @samp{SAS/C} sources. @file{pragmas} are
generated automatically during the building of @samp{FD2InLine} by an
@samp{AWK} script, so you might either have a look at the
@file{fd2inline-@value{version}-src.lha} archive, or simply create
@file{pragmas} file by hand.

Creating a linker library with stubs might also be useful, in case
somebody doesn't want to, or can't, use inline headers.

@file{fd2inline-@value{version}-src.lha} contains necessary support
for this. For example, to generate a library @file{libexec.a} with
@samp{exec.library} stubs, you should type:

@example
make alllib INCBASE=exec LIBBASE=exec
@end example

This will create three @file{libexec.a} libraries in @file{lib}
subdirectory: plain, base relative and 32-bit base relative one. Of
course, this particular example doesn't make much sense since
@file{libamiga.a} already contains these stubs.

@code{INCBASE} and @code{LIBBASE} specify the base names of the
(input) @samp{proto} and @samp{fd} files and the (output) library.
This will often be the same, but not always. For example, in the case
of @samp{MUI}, @code{INCBASE} has to be set to @code{muimaster}, but
@code{LIBBASE} should be set to @code{mui}.

@node Rebuilding, Internals, Usage, Top
@chapter Rebuilding
@cindex Rebuilding

First, you have to get the @file{fd2inline-@value{version}-src.lha}
archive.

Unarchive it. You might either build @samp{FD2InLine} in source
directory or in a separate, build directory. The latter is
recommended. Type:

@example
lha -mraxe x fd2inline-@value{version}-src.lha
mkdir fd2inline-bin
cd fd2inline-bin
sh ../fd2inline-@value{version}/configure --prefix=/gg
make
@end example

This should build the @samp{FD2InLine} executable, headers, libraries
and so on.

Please note that the @samp{fd} files should be available in one of the
standard locations. For the AmigaOS @samp{fd} files, this is one of:
@file{GG:os-lib/fd/amigaos}, @file{GG:os-lib/fd}, @file{FD:}. For p.OS
@samp{fd} files, this is one of @file{GG:os-lib/fd/pos},
@file{P:/pOS_FD}. The exact location is determined by the
@samp{configure} script. If it doesn't find the @samp{fd} files, it
will disable the @file{Makefile} rules that build the @samp{inlines}.

You can then type:

@example
make install
@end example

This will install @samp{fd2inline}, the @samp{inlines} and the
documentation in the appropriate subdirectories of @file{GG:}.

The @file{fd2inline-@value{version}-src.lha} archive contains four
patches in unified diff format, in directory @file{patches}. They fix
bugs in AmigaOS 3.1 headers and @samp{fd} files. Without applying
@file{amigaguide_lib.fd.diff} to @samp{amigaguide.library} @samp{fd}
file, the produced @samp{inlines} will be broken. Applying
@file{timer.h.diff} to @file{devices/timer.h} will prevent collision
with IXEmul's @file{sys/time.h}. Two other patches rename an argument
name from @code{true} to @code{tf}, since @code{true} is a reserved
word in @samp{C++}. Use @code{patch} to apply these patches, for
example:

@example
cd GG:os-lib/fd
patch amigaguide_lib.fd <amigaguide_lib.fd.diff
@end example

@samp{GeekGadgets} distribution contains more complete set of patches.

@cindex Source code
A few words about the source code:

I know, it's not state-of-the-art @samp{C} programming example.
However, believe me, it was in @emph{much} worse condition when I took
it over. In its current state it is at least readable (if you use tab
size 3, as I do :-). I think that rewriting it in @samp{C++} would
clean it up considerably (it's already written in @samp{OO} fashion,
so this should be quite easy). Using @code{flex} and @code{bison} to
create the parser would also be a nice thing, I guess. However, I
don't think it's worth the effort. But, if somebody wants to do it:
feel free, this is @samp{GNU} software, so everybody can modify it.

@node Internals, History, Rebuilding, Top
@chapter Internals
@cindex Internals

This chapter describes the implementation details of @samp{inlines}.

@menu
* Background::    Function calls in AmigaOS shared libraries.
* Old format::    Inlines that use @code{__inline}.
* New format::    Inlines that use the preprocessor.
* p.OS format::   Inlines used for p.OS.
* Stubs format::  Not really inlines, but...
@end menu

@node Background, Old format, Internals, Internals
@section Background
@cindex Background
@cindex Function calls format in AmigaOS shared libraries

This section describes the calling conventions used in the AmigaOS
shared libraries.

@cindex Libraries
User-callable functions in the AmigaOS are organized in
@dfn{libraries}.

@cindex Library base
@cindex Jump table
From our point of view, the most important part of a library is the
@dfn{library base}. It always resides in RAM and contains library
variables and a @dfn{jump table}. The location of the library base
varies. You can obtain the library base location of the main system
library --- @code{exec.library} --- by dereferencing
@code{0x00000004}. Locations of other library bases can be obtained
using the @code{OpenLibrary} function of @samp{exec.library}.

Without providing unnecessary details, every function in a library has
a fixed location in the library's jump table. To call a function, one
has to jump to this location.

@cindex Function arguments
Most functions require some arguments. In @samp{C}, these are usually
passed on the CPU stack. However, for some obscure reason, AmigaOS
system designers decided that arguments to shared libraries should be
passed in CPU registers.

@cindex FD files
All the information required to make library function calls is
provided in @dfn{fd} files. Every shared library should have such a
file. It provides the name a library base variable should have, the
offset in the jump table where each library function resides, and
information about which arguments should be passed in which registers.

@cindex CLIB files
In order to check if arguments passed to a function have the correct
type, the @samp{C} compiler requires function prototypes. These are
provided in @dfn{clib} files --- every library should have such a
file.

@cindex Varargs functions
Starting with the AmigaOS release 2.0, certain functions have been
provided which accept a variable number of arguments (so-called
@dfn{varargs functions}). Actually, these are only @samp{C} language
stubs. Internally, all optional arguments have to be put into an array
of @samp{long ints} and the address of this array must be passed to a
fixed args library function.

@cindex Linker libraries
To implement calls to shared library functions, compiler vendors have
to either use some compiler-dependent tricks to make these calls
directly (so-called @dfn{in line}), or provide linker libraries with
function stubs, usually written in assembler. In the latter case, a
function call from the user's code is compiled as usual --- arguments
are passed on the stack. Then, in the linking stage, a library stub
gets linked in. When this stub is called during program execution, it
moves the arguments from the stack to the appropriate registers and
jumps to the library jump table. Needless to say, this is slower than
making a call in line.

@node Old format, New format, Background, Internals
@section Old format
@cindex Old inlines format

@example
extern __inline APTR
OpenAmigaGuideA(BASE_PAR_DECL struct NewAmigaGuide *nag, struct TagItem *attrs)
@{
   BASE_EXT_DECL
   register APTR res __asm("d0");
   register struct Library *a6 __asm("a6") = BASE_NAME;
   register struct NewAmigaGuide *a0 __asm("a0") = nag;
   register struct TagItem *a1 __asm("a1") = attrs;
   __asm volatile ("jsr a6@@(-0x36:W)"
   : "=r" (res)
   : "r" (a6), "r" (a0), "r" (a1)
   : "d0", "d1", "a0", "a1", "cc", "memory");
   return res;
@}
@end example

In this implementation, the AmigaOS shared library function stubs are
external functions. They are defined as @code{__inline}, making
@samp{GCC} insert them at every place of call. The mysterious
@code{BASE_PAR_DECL} and @code{BASE_EXT_DECL} defines are hacks
necessary for local library base support (which is quite hard to
achieve, so it will not be described here). The biggest disadvantage
of these @samp{inlines} is that compilation becomes very slow,
requiring huge amounts of memory. Besides, inlining only works with
optimization enabled.

@example
#ifndef NO_INLINE_STDARG
#define OpenAmigaGuide(a0, tags...) \
   (@{ULONG _tags[] = @{ tags @}; OpenAmigaGuideA((a0), (struct TagItem *)_tags);@})
#endif /* !NO_INLINE_STDARG */
@end example

@cindex Varargs problems
The source above shows how @samp{varargs} functions are implemented.
Handling them cannot be made using @code{__inline} functions, since
@code{__inline} functions require a fixed number of arguments.
Therefore, the unique features of the @samp{GCC} preprocessor (such as
@samp{varargs macros}) have to be used, instead. This has some
drawbacks, unfortunately. Since these are actually preprocessor macros
and not function calls, you cannot make tricky things involving the
preprocessor inside them. For example:

@example
#include <proto/amigaguide.h>

#define OPENAG_BEG OpenAmigaGuide(
#define OPENAG_END , TAG_DONE)

void f(void)
@{
   OPENAG_BEG "a_file.guide" OPENAG_END;
   OpenAmigaGuide(
#ifdef ABC
      "abc.guide",
#else
      "def.guide",
#endif
      TAG_DONE);
@}
@end example

Neither of the above @code{OpenAmigaGuide()} calls is handled
correctly.

In the case of the first call, you get an error:

@example
unterminated macro call
@end example

By the time the preprocessor attempts to expand the
@code{OpenAmigaGuide} macro, @code{OPENAG_END} is not yet expanded, so
the preprocessor cannot find the closing bracket. This code might look
contrived, but @samp{MUI}, for example, defines such macros to make
code look more pretty.

In the case of the second call, you'll see:

@example
warning: preprocessing directive not recognized within macro arg
@end example

A workaround would be to either surround entire function calls with
conditions, or to conditionally define a preprocessor symbol
@code{GUIDE} somewhere above and simply put @code{GUIDE} as a function
argument:

@example
#ifdef ABC
#define GUIDE "abc.guide"
#else
#define GUIDE "def.guide"
#endif

void f(void)
@{
#ifdef ABC
   OpenAmigaGuide("abc.guide", TAG_DONE);
#else
   OpenAmigaGuide("def.guide", TAG_DONE);
#endif
   OpenAmigaGuide(GUIDE, TAG_DONE);
@}
@end example

Another problem is that when you pass a pointer as an argument, you
get a warning:

@example
warning: initialization makes integer from pointer without a cast
@end example

This is because all optional arguments are put as initializers to an
array of @code{ULONG}. And, if you attempt to initialize an
@code{ULONG} with a pointer without a cast, you get a warning. You can
avoid it by explicit casting of all pointer arguments to @code{ULONG}.

Because of these drawbacks, @samp{varargs inlines} can be disabled by
defining @code{NO_INLINE_STDARG} before including a @samp{proto} file.
In such a case, you will need a library with function stubs.

@node New format, p.OS format, Old format, Internals
@section New format
@cindex New inlines format

@example
#define OpenAmigaGuideA(nag, attrs) \
   LP2(0x36, APTR, OpenAmigaGuideA, struct NewAmigaGuide *, nag, a0, struct TagItem *, attrs, a1, \
   , AMIGAGUIDE_BASE_NAME)
@end example

As you can see, this implementation is much more compact. The
@code{LP2} macro (and others) are defined in @file{inline/macros.h},
which is included at the beginning of every @samp{inline} file.

@example
#define LP2(offs, rt, name, t1, v1, r1, t2, v2, r2, bt, bn) \
(@{                                                     \
   t1 _##name##_v1 = (v1);                              \
   t2 _##name##_v2 = (v2);                              \
   @{                                                   \
      register rt _##name##_re __asm("d0");             \
      register struct Library *const _##name##_bn __asm("a6") = (struct Library*)(bn);\
      register t1 _n1 __asm(#r1) = _##name##_v1;        \
      register t2 _n2 __asm(#r2) = _##name##_v2;        \
      __asm volatile ("jsr a6@@(-"#offs":W)"            \
      : "=r" (_##name##_re)                             \
      : "r" (_##name##_bn), "r"(_n1), "r"(_n2)          \
      : "d0", "d1", "a0", "a1", "cc", "memory");        \
      _##name##_re;                                     \
   @}                                                   \
@})
@end example

If you compare this with the old @samp{inlines} (@pxref{Old format})
you will notice many similarities. Indeed, both implementations use
the same tricks. This means that there should be little, if any,
difference in code quality between old and new @samp{inlines}.

With the new @samp{inlines}, however, inlining is performed very
early, at the preprocessing stage. This makes compilation much faster,
less memory hungry, and independent of the optimization options used.
This also makes it very easy to use local library bases --- all that
is needed is to define a local variable with the same name as library
base.

Unfortunately, using the preprocessor instead of the compiler for
making function calls has its drawbacks, as described earlier
(@pxref{Old format}). There is not much you can do about it apart from
modifying your code.

Depending on the type of a function, @samp{FD2InLine} generates calls
to different @samp{LP} macros.

Macros are distinguished by one or more of the qualifiers described
below:

@table @samp
@item digit
As you may have already guessed, digit indicates the number of
arguments a function accepts. Therefore, it is mandatory.

@item NR
This indicates a ``no return'' (@code{void}) function.

@item A4, A5
These two are used when one of the arguments has to be in either the
@samp{a4} or @samp{a5} register. In certain situations, these
registers have special meaning and have to be handled more carefully.

@item UB
This indicates ``user base'' --- the library base pointer has to be
specified explicitly by the user. Currently, this is used for
@samp{cia.resource} only. Since there are two @samp{CIA} chips, the
programmer has to specify which one [s]he wants to use.

@item FP
This means that one of the arguments is of type ``pointer to a
function''. To overcome strange @samp{C} syntax rules in this case,
inside @samp{FP} macros a @code{typedef} to @code{__fpt} is performed.
The @samp{inline} file passes @code{__fpt} as the argument type to the
@samp{LP} macro. The actual type of the argument, in a form suitable
for a @code{typedef}, is passed as an additional, last argument.
@end table

As you can see, there could be more than a hundred different
variations of the @samp{LP} macros. @file{inline/macros.h} contains
only 35, which are used in the current OS version and supported 3rd
party libraries. More macros will be added in the future, if needed.

If you look carefully at the definition of @code{OpenAmigaGuideA} at
the beginning of this section, you might notice that the next to last
argument to the @samp{LP} macro is not used. New @samp{inlines} were
not implemented in one evening, and they went through many
modifications. This unused argument (which was once a type of library
base pointer) is provided for backwards compatibility. Actually, there
are more unnecessary arguments, like function and argument names, but
it was decided to leave them in peace.

@node p.OS format, Stubs format, New format, Internals
@section p.OS format
@cindex p.OS inlines format
@cindex Function calls format in p.OS shared libraries

p.OS uses a different calling convention than AmigaOS. The most
fundamental difference is that, despite the information contained in
the @samp{fd} files, the arguments are passed on the stack, not in the
CPU registers.

@example
#define pOS_AllocAudioMapA(channel, par2) \
        __INLINE_FUN_2(__AUDIO_BASE_NAME, __AUDIO_LIB_NAME, 0x12c, __ARID__ struct pOS_AudioMap*, pOS_AllocAudioMapA, \
        ULONG, channel, __INLINE_REG_D0, const struct pOS_TagItem*, par2, __INLINE_REG_A0)
@end example

As you can see, the p.OS @samp{inlines} format largely resembles the
new @samp{inlines} format (@pxref{New format}). The most important
difference is that all the preprocessor symbols are now prefixed with
two underscores @code{__}, in order to prevent user namespace
polution, as required by @samp{ANSI C}.

@example
#define __INLINE_FUN_2(__base, __lib, __offs, __type, __name, __type1, __name1, __reg1, __type2, __name2, __reg2) \
((__type (*)(void*, __type1, __type2)) \
*(ULONG*)(((char*)__lib)-__offs))(__base, __name1, __name2)
@end example

The actual implementation is very simple: no @samp{GNU CC}-specific
features are used, every @samp{ANSI C}-compatible compiler should be
able to use this inlines format.

As you might have already noticed, the register names are passed, but
not used. As mentioned earlier in this section, p.OS does not pass the
arguments in registers. However, since it is not clear if it will
continue to do so, it was decided to pass this redundant information.

Another difference when compared to AmigaOS is that p.OS supports
library jump tables separated from the library bases. As of this
writing, this is only the case of @samp{pexec.library}, where the base
pointer is identified by @code{gb_ExecBase}, and the jump table by
@code{gb_ExecLib}, both of which are obtained form the
@code{gb_DosBase}, passed to every application invoked. For this
reason, p.OS @samp{inlines} provide two preprocessor symbols for
library identification (@pxref{Using inlines under p.OS}).

@node Stubs format, , p.OS format, Internals
@section Stubs format
@cindex Stubs inlines format

Stubs format is very similar to old format (@pxref{Old format}). The
functions are not defined as @code{extern}, however.

The main difference is the format of the @samp{varargs} functions ---
they are plain functions, not preprocessor macros.

@example
APTR OpenAmigaGuide(struct NewAmigaGuide *nag, int tag, ...)
@{
   return OpenAmigaGuideA(nag, (struct TagItem *)&tag);
@}
@end example

This format is not suitable for inlining, and it is not provided for
this purpose. It is provided for the building of linker libraries with
stubs (@pxref{Using fd2inline}).

@node History, Authors, Internals, Top
@chapter History
@cindex History
@cindex What has changed

Version 1.37,  April 22:nd, 2003,  Martin Blom
@itemize @bullet
@item
Targets are now specified in such a way that canonical system
names (from config.sub) can be used, as well as the short names.
@item
Added some AROS support (old and stubs do not yet work).
@item
@samp{--gatestubs} now works for all targets.
@item
Added @samp{--gateproto}.
@item
Added @samp{--mode}, @samp{--gateprefix} and @samp{--libprefix}.
@end itemize

Version 1.36,  February 24:th, 2002,  Martin Blom
@itemize @bullet
@item
Added @samp{--gatestubs} for AmigaOS and MorphOS.
@end itemize

Version 1.35,  February 2nd, 2002,  Martin Blom
@itemize @bullet
@item
Modified @file{share/ix86be-amithlon/macros.h} to use _CallLib68k().
@item
When creating stubs or old-style inlines, the macros from
@file{inline/macros.h} are now used.
@end itemize

Version 1.34,  January 6th, 2002,  Martin Blom
@itemize @bullet
@item
Modified @file{share/ix86be-amithlon/macros.h} to use a variable length
array for the register structure. This reduces the stack usage
dramatically, since variable length arrays are deallocated when it goes
out of scope, not when the function returns. I also added a7 to the
register structure (it's not used when calling OS functions, though).
@end itemize

Version 1.33,  December 14th, 2001,  Martin Blom
@itemize @bullet
@item
The @samp{--stubs} option was broken (at least) for ix86be-amithlon and
ppc-morphos. In addition, it's now possible to define the preprocessor
macro @var{__CLIB_TYPES__} and get all includes and typedefs from the
clib file included.
@item
In order to avoid problems where a parameter name is the same as a typedef,
all parameters are now prefixed with three underscores.
@end itemize

Version 1.32,  December 1st, 2001,  Martin Blom
@itemize @bullet
@item
Inlines and @file{macros.h} for @samp{ix86be-amithlon} now include the
unused @var{bt} argument. It made it easier to port libnix that way
@enddots{}
@end itemize

Version 1.31,  October 14th, 2001,  Martin Blom
@itemize @bullet
@item
Added added the @samp{ix86be-amithlon} target.
@item
Added the varproto code from version 2.00.
@item
Added more compability options: --powerup and --morphos.
@end itemize

Version 1.30,  October 11th, 2001,  Martin Blom
@itemize @bullet
@item
Backported some of Ralphs and Emmanuels updates from
version 2.00 (the PowerUp and MorphOS support; @samp{--pragma} and
@samp{--gatestubs} are not included).
@item
Added @samp{--quiet}.
@item
Fixed tag calls declared @code{CONST struct TagItem *} instead of
just @code{const struct TagItem *}.
@end itemize

Version 1.21,  March 22nd, 1998,  Kamil Iskra
@itemize @bullet
@item
Fixed a bug in handling of prototypes where the argument name was the
same as the type name (Kamil Iskra, reported by Martin Hauner).
@end itemize

Version 1.2,  October 26th, 1997,  Kamil Iskra
@itemize @bullet
@item
Added @code{LP10} macro to @file{inline/macros.h}, needed by
CyberGraphics (Kriton Kyrimis).
@item
New version of @file{strsup.h} (Gunther Nikl).
@item
Integrated support for p.OS (Kamil Iskra).
@item
Replaced "r" constraints with "rf" in @file{inline/macros.h} to
support passing arguments in floating point registers. NOTE: full
support in @samp{FD2InLine} is not yet available (Kamil Iskra).
@item
Modified source structure so that rebuilding @samp{FD2InLine} does not
require having it already installed (Kamil Iskra).
@item
Added consistency checks to prevent @samp{FD2InLine} from crashing
when certain parsing errors occur (Kamil Iskra).
@end itemize

Version 1.11,  January 31st, 1997,  Kamil Iskra
@itemize @bullet
@item
Minor fixes in @file{Makefile.in} for @samp{ADE} tree (Fred Fish).
@item
Fixed handling of prototypes in which the argument name was the same
as the type name (Kamil Iskra, reported by Martin Recktenwald).
@item
Added support for building 32-bit base relative linker libraries
(Kamil Iskra).
@item
Added a paragraph about @code{void} functions (Kamil Iskra, suggested
by Martin Recktenwald).
@end itemize

Version 1.1,  October 24th, 1996,  Kamil Iskra
@itemize @bullet
@item
Removed a lot of language mistakes from the documentation (Kriton
Kyrimis).
@item
Inlines of @samp{dospath.library}, @samp{screennotify.library},
@samp{ums.library} and @samp{wbstart.library} integrated (Martin
Steigerwald).
@item
Inlines of @samp{muimaster.library} integrated (Kamil Iskra).
@item
Floating point registers @samp{fp0} and @samp{fp1} are now marked as
clobbered (Kamil Iskra, reported by Kriton Kyrimis).
@item
Improved handling of @samp{clib} files, particularly recognition of
function prototypes and varargs functions (Kamil Iskra).
@item
Added support for @samp{--proto} and @samp{--version} options. Minor
changes in output file generators, most notably making @samp{proto}
files work with other compilers than @samp{GCC}, too. Finalized
support for building linker libraries (Kamil Iskra, change in
@samp{proto} files suggested by Joop van de Wege).
@end itemize

Version 1.0,  July 14th, 1996,  Kamil Iskra
@itemize @bullet
@item
First officially available version.
@end itemize

@node Authors, Index, History, Top
@chapter Authors
@cindex Authors
@cindex Other parsers
@cindex Reporting bugs
@cindex Address
@cindex Latest version

The first parser for @samp{GCC inlines} was written in @samp{Perl} by
Markus Wild.

It had several limitations, which were apparently hard to fix in
@samp{Perl}. This is why Wolfgang Baron decided to write a new parser
in @samp{C}.

For some reason, however, he never finished it. In early 1995. Rainer
F. Trunz took over its development and ``improved, updated, simply
made it workable'' (quotation from the change log). It still contained
quite a few bugs, though.

In more-or-less the same time, I started a discussion on the
@samp{amiga-gcc-port} mailing list about improving the quality of
@samp{inlines}. The most important idea came from Matthias Fleischer,
who introduced the new format of @samp{inlines} (@pxref{New format}).
Since I started the discussion, I volunteered to make improvements to
the @samp{inlines} parser. Having no idea about programming in
@samp{Perl}, I decided to modify the parser written in @samp{C}. I
fixed all the bugs known to me, added some new features, and wrote
this terribly long documentation :-).

Ralph Schmidt and Emmanuel Lesueur added PowerUp and MorphOS support
(version 2.00).

Martin Blom backported some of their work to version 1.xx and added support
for ix86be-amithlon and AROS.

Not all of the files distributed in the @samp{FD2InLine} archives were
created by me or @samp{FD2InLine}. Most of the files in
@file{include-src/proto} and @file{include-src/inline} (@file{alib.h},
@file{strsub.h} and @file{stubs.h}) were written by Gunther Nikl (with
some modifications by Joerg Hoehle and me).

If you have any comments concerning this work, please write to:

gg-gcc@@ninemoons.com

This is a list to which most of the @samp{GeekGadgets} developers and
activists subscribe, so you are practically guaranteed to get a reply.

However, if, for some reason, you want to contact me personally, you
can do so in one of the following ways:

@itemize @bullet
@item
E-mail (preferred :-):

iskra@@student.uci.agh.edu.pl

Should be valid until October 1999 (at least I hope so :-).

@item
Snail-mail (expect to wait long for a reply :-):

@format
Kamil Iskra
Luzycka 51/258
30-658 Krakow
Poland
@end format
@end itemize

Latest version of this package should always be available on my WWW
page:

@format
http://student.uci.agh.edu.pl/~iskra
@end format

@node Index, , Authors, Top
@chapter Index
@printindex cp

@contents
@bye