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fragments.texi, [...]: Update to reflect current (lack of) need for host configuration by hand.

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* doc/fragments.texi, doc/hostconfig.texi: Update to reflect
	current (lack of) need for host configuration by hand.

	* doc/gccint.texi, doc/rtl.texi, doc/tm.texi: Adjust cross
	references.  Documentation of some target macros moved from
	hostconfig.texi to tm.texi.

From-SVN: r49142
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Zack Weinberg 2002-01-23 17:30:28 +00:00 committed by Zack Weinberg
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
2002-01-23 Zack Weinberg <zack@codesourcery.com>
* doc/fragments.texi, doc/hostconfig.texi: Update to reflect
current (lack of) need for host configuration by hand.
* doc/gccint.texi, doc/rtl.texi, doc/tm.texi: Adjust cross
references. Documentation of some target macros moved from
hostconfig.texi to tm.texi.
2002-01-23 Will Cohen <wcohen@redhat.com>
* config/arm/arm.h (THUMB_FUNCTION_PROFILER): Define if not currently

73
gcc/doc/fragments.texi
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@ -7,26 +7,36 @@
@chapter Makefile Fragments
@cindex makefile fragment
When you configure GCC using the @file{configure} script,
it will construct the file @file{Makefile} from
the template file @file{Makefile.in}. When it does this, it will
incorporate makefile fragment files from the @file{config} directory,
named @file{t-@var{target}} and @file{x-@var{host}}. If these files do
not exist, it means nothing needs to be added for a given target or
host.
When you configure GCC using the @file{configure} script, it will
construct the file @file{Makefile} from the template file
@file{Makefile.in}. When it does this, it can incorporate makefile
fragments from the @file{config} directory. These are used to set
Makefile parameters that are not amenable to being calculated by
autoconf. The list of fragments to incorporate is set by
@file{config.gcc}; @xref{System Config}.
Fragments are named either @file{t-@var{target}} or @file{x-@var{host}},
depending on whether they are relevant to configuring GCC to produce
code for a particular target, or to configuring GCC to run on a
particular host. Here @var{target} and @var{host} are mnemonics
which usually have some relationship to the canonical system name, but
no formal connection.
If these files do not exist, it means nothing needs to be added for a
given target or host. Most targets need a few @file{t-@var{target}}
fragments, but needing @file{x-@var{host}} fragments is rare.
@menu
* Target Fragment:: Writing the @file{t-@var{target}} file.
* Host Fragment:: Writing the @file{x-@var{host}} file.
* Target Fragment:: Writing @file{t-@var{target}} files.
* Host Fragment:: Writing @file{x-@var{host}} files.
@end menu
@node Target Fragment
@section The Target Makefile Fragment
@section Target Makefile Fragments
@cindex target makefile fragment
@cindex @file{t-@var{target}}
The target makefile fragment, @file{t-@var{target}}, defines special
target dependent variables and targets used in the @file{Makefile}:
Target makefile fragments can set these Makefile variables.
@table @code
@findex LIBGCC2_CFLAGS
@ -141,19 +151,40 @@ of options to be used for all builds.
@end table
@node Host Fragment
@section The Host Makefile Fragment
@section Host Makefile Fragments
@cindex host makefile fragment
@cindex @file{x-@var{host}}
The host makefile fragment, @file{x-@var{host}}, defines special host
dependent variables and targets used in the @file{Makefile}:
The use of @file{x-@var{host}} fragments is discouraged. You should do
so only if there is no other mechanism to get the behavior desired.
Host fragments should never forcibly override variables set by the
configure script, as they may have been adjusted by the user.
Variables provided for host fragments to set include:
@table @code
@findex CC
@item CC
The compiler to use when building the first stage.
@findex INSTALL
@item INSTALL
The install program to use.
@item X_CFLAGS
@itemx X_CPPFLAGS
These are extra flags to pass to the C compiler and preprocessor,
respectively. They are used both when building GCC, and when compiling
things with the just-built GCC.
@item XCFLAGS
These are extra flags to use when building the compiler. They are not
used when compiling @file{libgcc.a}. However, they @emph{are} used when
recompiling the compiler with itself in later stages of a bootstrap.
@item BOOT_LDFLAGS
Flags to be passed to the linker when recompiling the compiler with
itself in later stages of a bootstrap. You might need to use this if,
for instance, one of the front ends needs more text space than the
linker provides by default.
@item EXTRA_PROGRAMS
A list of additional programs required to use the compiler on this host,
which should be compiled with GCC and installed alongside the front
ends. If you set this variable, you must also provide rules to build
the extra programs.
@end table

2
gcc/doc/gccint.texi
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@ -165,7 +165,7 @@ Additional tutorial information is linked to from
* RTL:: The intermediate representation that most passes work on.
* Machine Desc:: How to write machine description instruction patterns.
* Target Macros:: How to write the machine description C macros and functions.
* Config:: Writing the @file{xm-@var{machine}.h} file.
* Host Config:: Writing the @file{xm-@var{machine}.h} file.
* Fragments:: Writing the @file{t-@var{target}} and @file{x-@var{host}} files.
* Collect2:: How @code{collect2} works; how it finds @code{ld}.
* Header Dirs:: Understanding the standard header file directories.

259
gcc/doc/hostconfig.texi
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@ -1,38 +1,32 @@
@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
@c 1999, 2000, 2001 Free Software Foundation, Inc.
@c 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@node Config
@chapter The Configuration File
@node Host Config
@chapter Host Configuration Headers
@cindex configuration file
@cindex @file{xm-@var{machine}.h}
The configuration file @file{xm-@var{machine}.h} contains macro
definitions that describe the machine and system on which the compiler
is running, unlike the definitions in @file{@var{machine}.h}, which
describe the machine for which the compiler is producing output. Most
of the values in @file{xm-@var{machine}.h} are actually the same on all
machines that GCC runs on, so large parts of all configuration files
are identical. But there are some macros that vary:
Host configuration headers contain macro definitions that describe the
machine and system on which the compiler is running. They are usually
unnecessary. Most of the things GCC needs to know about the host
system can be deduced by the @command{configure} script.
@table @code
@findex USG
@item USG
Define this macro if the host system is System V@.
If your host does need a special configuration header, it should be
named @file{xm-@var{machine}.h}, where @var{machine} is a short mnemonic
for the machine. Here are some macros which this header can define.
@findex VMS
@ftable @code
@item VMS
Define this macro if the host system is VMS@.
@findex FATAL_EXIT_CODE
@item FATAL_EXIT_CODE
A C expression for the status code to be returned when the compiler
exits after serious errors. The default is the system-provided macro
@samp{EXIT_FAILURE}, or @samp{1} if the system doesn't define that
macro. Define this macro only if these defaults are incorrect.
@findex SUCCESS_EXIT_CODE
@item SUCCESS_EXIT_CODE
A C expression for the status code to be returned when the compiler
exits without serious errors. (Warnings are not serious errors.) The
@ -40,189 +34,66 @@ default is the system-provided macro @samp{EXIT_SUCCESS}, or @samp{0} if
the system doesn't define that macro. Define this macro only if these
defaults are incorrect.
@findex HOST_WORDS_BIG_ENDIAN
@item HOST_WORDS_BIG_ENDIAN
Defined if the host machine stores words of multi-word values in
big-endian order. (GCC does not depend on the host byte ordering
within a word.)
@findex HOST_FLOAT_WORDS_BIG_ENDIAN
@item HOST_FLOAT_WORDS_BIG_ENDIAN
Define this macro to be 1 if the host machine stores @code{DFmode},
@code{XFmode} or @code{TFmode} floating point numbers in memory with the
word containing the sign bit at the lowest address; otherwise, define it
to be zero.
This macro need not be defined if the ordering is the same as for
multi-word integers.
@findex HOST_FLOAT_FORMAT
@item HOST_FLOAT_FORMAT
A numeric code distinguishing the floating point format for the host
machine. See @code{TARGET_FLOAT_FORMAT} in @ref{Storage Layout} for the
alternatives and default.
@findex HOST_BITS_PER_CHAR
@item HOST_BITS_PER_CHAR
A C expression for the number of bits in @code{char} on the host
machine.
@findex HOST_BITS_PER_SHORT
@item HOST_BITS_PER_SHORT
A C expression for the number of bits in @code{short} on the host
machine.
@findex HOST_BITS_PER_INT
@item HOST_BITS_PER_INT
A C expression for the number of bits in @code{int} on the host
machine.
@findex HOST_BITS_PER_LONG
@item HOST_BITS_PER_LONG
A C expression for the number of bits in @code{long} on the host
machine.
@findex HOST_BITS_PER_LONGLONG
@item HOST_BITS_PER_LONGLONG
A C expression for the number of bits in @code{long long} on the host
machine.
@findex ONLY_INT_FIELDS
@item ONLY_INT_FIELDS
Define this macro to indicate that the host compiler only supports
@code{int} bit-fields, rather than other integral types, including
@code{enum}, as do most C compilers.
@findex OBSTACK_CHUNK_SIZE
@item OBSTACK_CHUNK_SIZE
A C expression for the size of ordinary obstack chunks.
If you don't define this, a usually-reasonable default is used.
@findex OBSTACK_CHUNK_ALLOC
@item OBSTACK_CHUNK_ALLOC
The function used to allocate obstack chunks.
If you don't define this, @code{xmalloc} is used.
@findex OBSTACK_CHUNK_FREE
@item OBSTACK_CHUNK_FREE
The function used to free obstack chunks.
If you don't define this, @code{free} is used.
@findex USE_C_ALLOCA
@item USE_C_ALLOCA
Define this macro to indicate that the compiler is running with the
@code{alloca} implemented in C@. This version of @code{alloca} can be
found in the file @file{alloca.c}; to use it, you must also alter the
@file{Makefile} variable @code{ALLOCA}. (This is done automatically
for the systems on which we know it is needed.)
Define this macro if GCC should use the C implementation of @code{alloca}
provided by @file{libiberty.a}. This only affects how some parts of the
compiler itself allocate memory. It does not change code generation.
If you do define this macro, you should probably do it as follows:
When GCC is built with a compiler other than itself, the C @code{alloca}
is always used. This is because most other implementations have serious
bugs. You should define this macro only on a system where no
stack-based @code{alloca} can possibly work. For instance, if a system
has a small limit on the size of the stack, GCC's builtin @code{alloca}
will not work reliably.
@example
#ifndef __GNUC__
#define USE_C_ALLOCA
#else
#define alloca __builtin_alloca
#endif
@end example
@item HAVE_DOS_BASED_FILE_SYSTEM
Define this macro if the host file system obeys the semantics defined by
MS-DOS instead of Unix. DOS file systems are case insensitive, file
specifications may begin with a drive letter, and both forward slash and
backslash (@samp{/} and @samp{\}) are directory separators. If you
define this macro, you probably need to define the next three macros too.
@noindent
so that when the compiler is compiled with GCC it uses the more
efficient built-in @code{alloca} function.
@item FUNCTION_CONVERSION_BUG
@findex FUNCTION_CONVERSION_BUG
Define this macro to indicate that the host compiler does not properly
handle converting a function value to a pointer-to-function when it is
used in an expression.
@findex MULTIBYTE_CHARS
@item MULTIBYTE_CHARS
Define this macro to enable support for multibyte characters in the
input to GCC@. This requires that the host system support the ISO C
library functions for converting multibyte characters to wide
characters.
@findex POSIX
@item POSIX
Define this if your system is POSIX.1 compliant.
@findex PATH_SEPARATOR
@item PATH_SEPARATOR
Define this macro to be a C character constant representing the
character used to separate components in paths. The default value is
the colon character
If defined, this macro should expand to a character constant specifying
the separator for elements of search paths. The default value is a
colon (@samp{:}). DOS-based systems usually use semicolon (@samp{;}).
@findex DIR_SEPARATOR
@item DIR_SEPARATOR
If your system uses some character other than slash to separate
directory names within a file specification, define this macro to be a C
character constant specifying that character. When GCC displays file
names, the character you specify will be used. GCC will test for
both slash and the character you specify when parsing filenames.
@itemx DIR_SEPARATOR_2
If defined, these macros expand to character constants specifying
separators for directory names within a file specification. They are
used somewhat inconsistently throughout the compiler. If your system
behaves like Unix (only forward slash separates pathnames), define
neither of them. If your system behaves like DOS (both forward and
backward slash can be used), define @code{DIR_SEPARATOR} to @samp{/}
and @code{DIR_SEPARATOR_2} to @samp{\}.
@findex DIR_SEPARATOR_2
@item DIR_SEPARATOR_2
If your system uses an alternative character other than
@samp{DIR_SEPARATOR} to separate directory names within a file
specification, define this macro to be a C character constant specifying
that character. If you define this macro, GCC will test for slash,
@samp{DIR_SEPARATOR}, and @samp{DIR_SEPARATOR_2} when parsing filenames.
@findex TARGET_OBJECT_SUFFIX
@item TARGET_OBJECT_SUFFIX
Define this macro to be a C string representing the suffix for object
files on your target machine. If you do not define this macro, GCC will
use @samp{.o} as the suffix for object files.
@findex TARGET_EXECUTABLE_SUFFIX
@item TARGET_EXECUTABLE_SUFFIX
Define this macro to be a C string representing the suffix to be
automatically added to executable files on your target machine. If you
do not define this macro, GCC will use the null string as the suffix for
executable files.
@findex HOST_OBJECT_SUFFIX
@item HOST_OBJECT_SUFFIX
Define this macro to be a C string representing the suffix for object
files on your host machine (@samp{xm-*.h}). If you do not define this
macro, GCC will use @samp{.o} as the suffix for object files.
files on your host machine. If you do not define this macro, GCC will
use @samp{.o} as the suffix for object files.
@findex HOST_EXECUTABLE_SUFFIX
@item HOST_EXECUTABLE_SUFFIX
Define this macro to be a C string representing the suffix for
executable files on your host machine (@samp{xm-*.h}). If you do not
define this macro, GCC will use the null string as the suffix for
executable files.
executable files on your host machine. If you do not define this macro,
GCC will use the null string as the suffix for executable files.
@findex HOST_BIT_BUCKET
@item HOST_BIT_BUCKET
The name of a file or file-like object on the host system which acts as
a ``bit bucket''. If you do not define this macro, GCC will use
@samp{/dev/null} as the bit bucket. If the target does not support a
bit bucket, this should be defined to the null string, or some other
invalid filename. If the bit bucket is not writable, GCC will use a
temporary file instead.
A pathname defined by the host operating system, which can be opened as
a file and written to, but all the information written is discarded.
This is commonly known as a @dfn{bit bucket} or @dfn{null device}. If
you do not define this macro, GCC will use @samp{/dev/null} as the bit
bucket. If the host does not support a bit bucket, define this macro to
an invalid filename.
@findex COLLECT_EXPORT_LIST
@item COLLECT_EXPORT_LIST
If defined, @code{collect2} will scan the individual object files
specified on its command line and create an export list for the linker.
Define this macro for systems like AIX, where the linker discards
object files that are not referenced from @code{main} and uses export
lists.
@findex COLLECT2_HOST_INITIALIZATION
@item COLLECT2_HOST_INITIALIZATION
If defined, a C statement (sans semicolon) that performs host-dependent
initialization when @code{collect2} is being initialized.
@findex GCC_DRIVER_HOST_INITIALIZATION
@item GCC_DRIVER_HOST_INITIALIZATION
If defined, a C statement (sans semicolon) that performs host-dependent
initialization when a compilation driver is being initialized.
@findex UPDATE_PATH_HOST_CANONICALIZE
@item UPDATE_PATH_HOST_CANONICALIZE (@var{path})
If defined, a C statement (sans semicolon) that performs host-dependent
canonicalization when a path used in a compilation driver or
@ -231,19 +102,29 @@ canonicalized. If the C statement does canonicalize @var{path} into a
different buffer, the old path should be freed and the new buffer should
have been allocated with malloc.
@findex DUMPFILE_FORMAT
@item DUMPFILE_FORMAT
Define this macro to be a C string representing the format to use
for constructing the index part of the dump file name on your host machine.
If you do not define this macro, GCC will use @samp{.%02d.}. The full
filename will be the prefix of the assembler file name concatenated with
the string resulting from applying this format concatenated with a string
Define this macro to be a C string representing the format to use for
constructing the index part of debugging dump file names. The resultant
string must fit in fifteen bytes. The full filename will be the
concatenation of: the prefix of the assembler file name, the string
resulting from applying this format to an index number, and a string
unique to each dump file kind, e.g. @samp{rtl}.
@end table
@findex bzero
@findex bcmp
In addition, configuration files for system V define @code{bcopy},
@code{bzero} and @code{bcmp} as aliases. Some files define @code{alloca}
as a macro when compiled with GCC, in order to take advantage of the
benefit of GCC's built-in @code{alloca}.
If you do not define this macro, GCC will use @samp{.%02d.}. You should
define this macro if using the default will create an invalid file name.
@item SMALL_ARG_MAX
Define this macro if the host system has a small limit on the total
size of an argument vector. This causes the driver to take more care
not to pass unnecessary arguments to subprocesses.
@end ftable
In addition, if @command{configure} generates an incorrect definition of
any of the macros in @file{auto-host.h}, you can override that
definition in a host configuration header. If you need to do this,
first see if it is possible to fix @command{configure}.
If you need to define only a few of these macros, and they have simple
definitions, consider using the @code{xm_defines} variable in your
@file{config.gcc} entry instead of creating a host configuration header.
@xref{System Config}.

6
gcc/doc/rtl.texi
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@ -57,9 +57,9 @@ expression (``RTX'', for short) is a C structure, but it is usually
referred to with a pointer; a type that is given the typedef name
@code{rtx}.
An integer is simply an @code{int}; their written form uses decimal digits.
A wide integer is an integral object whose type is @code{HOST_WIDE_INT}
(@pxref{Config}); their written form uses decimal digits.
An integer is simply an @code{int}; their written form uses decimal
digits. A wide integer is an integral object whose type is
@code{HOST_WIDE_INT}; their written form uses decimal digits.
A string is a sequence of characters. In core it is represented as a
@code{char *} in usual C fashion, and it is written in C syntax as well.

35
gcc/doc/tm.texi
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@ -1313,7 +1313,7 @@ need to define this macro when the format is IEEE@.
@findex VAX_FLOAT_FORMAT
@item VAX_FLOAT_FORMAT
This code indicates the peculiar format used on the VAX.
This code indicates the ``D float'' format used on the VAX@.
@findex IBM_FLOAT_FORMAT
@item IBM_FLOAT_FORMAT
@ -1328,14 +1328,14 @@ This code indicates the format used on the TMS320C3x/C4x.
This code indicates any other format.
@end table
The value of this macro is compared with @code{HOST_FLOAT_FORMAT}
(@pxref{Config}) to determine whether the target machine has the same
format as the host machine. If any other formats are actually in use on
supported machines, new codes should be defined for them.
The value of this macro is compared with @code{HOST_FLOAT_FORMAT}, which
is defined by the @command{configure} script, to determine whether the
target machine has the same format as the host machine. If any other
formats are actually in use on supported machines, new codes should be
defined for them.
The ordering of the component words of floating point values stored in
memory is controlled by @code{FLOAT_WORDS_BIG_ENDIAN} for the target
machine and @code{HOST_FLOAT_WORDS_BIG_ENDIAN} for the host.
memory is controlled by @code{FLOAT_WORDS_BIG_ENDIAN}.
@end table
@ -8600,4 +8600,25 @@ You may use @code{current_function_leaf_function} in the definition of the
macro, functions that use @code{REG_N_SETS}, to determine if the hard
register in question will not be clobbered.
@findex TARGET_OBJECT_SUFFIX
@item TARGET_OBJECT_SUFFIX
Define this macro to be a C string representing the suffix for object
files on your target machine. If you do not define this macro, GCC will
use @samp{.o} as the suffix for object files.
@findex TARGET_EXECUTABLE_SUFFIX
@item TARGET_EXECUTABLE_SUFFIX
Define this macro to be a C string representing the suffix to be
automatically added to executable files on your target machine. If you
do not define this macro, GCC will use the null string as the suffix for
executable files.
@findex COLLECT_EXPORT_LIST
@item COLLECT_EXPORT_LIST
If defined, @code{collect2} will scan the individual object files
specified on its command line and create an export list for the linker.
Define this macro for systems like AIX, where the linker discards
object files that are not referenced from @code{main} and uses export
lists.
@end table