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This is Info file gcc.info, produced by Makeinfo version 1.68 from the
input file gcc.texi.
This file documents the use and the internals of the GNU compiler.
Published by the Free Software Foundation 59 Temple Place - Suite 330
Boston, MA 02111-1307 USA
Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
Free Software Foundation, Inc.
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.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the sections entitled "GNU General Public License," "Funding for
Free Software," and "Protect Your Freedom--Fight `Look And Feel'" are
included exactly as in the original, and provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the sections entitled "GNU General Public
License," "Funding for Free Software," and "Protect Your Freedom--Fight
`Look And Feel'", and this permission notice, may be included in
translations approved by the Free Software Foundation instead of in the
original English.

File: gcc.info, Node: DEC Alpha Options, Next: Clipper Options, Prev: Intel 960 Options, Up: Submodel Options
DEC Alpha Options
-----------------
These `-m' options are defined for the DEC Alpha implementations:
`-mno-soft-float'
`-msoft-float'
Use (do not use) the hardware floating-point instructions for
floating-point operations. When `-msoft-float' is specified,
functions in `libgcc1.c' will be used to perform floating-point
operations. Unless they are replaced by routines that emulate the
floating-point operations, or compiled in such a way as to call
such emulations routines, these routines will issue floating-point
operations. If you are compiling for an Alpha without
floating-point operations, you must ensure that the library is
built so as not to call them.
Note that Alpha implementations without floating-point operations
are required to have floating-point registers.
`-mfp-reg'
`-mno-fp-regs'
Generate code that uses (does not use) the floating-point register
set. `-mno-fp-regs' implies `-msoft-float'. If the floating-point
register set is not used, floating point operands are passed in
integer registers as if they were integers and floating-point
results are passed in $0 instead of $f0. This is a non-standard
calling sequence, so any function with a floating-point argument
or return value called by code compiled with `-mno-fp-regs' must
also be compiled with that option.
A typical use of this option is building a kernel that does not
use, and hence need not save and restore, any floating-point
registers.
`-mieee'
The Alpha architecture implements floating-point hardware
optimized for maximum performance. It is mostly compliant with
the IEEE floating point standard. However, for full compliance,
software assistance is required. This option generates code fully
IEEE compliant code *except* that the INEXACT FLAG is not
maintained (see below). If this option is turned on, the CPP
macro `_IEEE_FP' is defined during compilation. The option is a
shorthand for: `-D_IEEE_FP -mfp-trap-mode=su -mtrap-precision=i
-mieee-conformant'. The resulting code is less efficient but is
able to correctly support denormalized numbers and exceptional
IEEE values such as not-a-number and plus/minus infinity. Other
Alpha compilers call this option `-ieee_with_no_inexact'.
`-mieee-with-inexact'
This is like `-mieee' except the generated code also maintains the
IEEE INEXACT FLAG. Turning on this option causes the generated
code to implement fully-compliant IEEE math. The option is a
shorthand for `-D_IEEE_FP -D_IEEE_FP_INEXACT' plus the three
following: `-mieee-conformant', `-mfp-trap-mode=sui', and
`-mtrap-precision=i'. On some Alpha implementations the resulting
code may execute significantly slower than the code generated by
default. Since there is very little code that depends on the
INEXACT FLAG, you should normally not specify this option. Other
Alpha compilers call this option `-ieee_with_inexact'.
`-mfp-trap-mode=TRAP MODE'
This option controls what floating-point related traps are enabled.
Other Alpha compilers call this option `-fptm 'TRAP MODE. The
trap mode can be set to one of four values:
`n'
This is the default (normal) setting. The only traps that
are enabled are the ones that cannot be disabled in software
(e.g., division by zero trap).
`u'
In addition to the traps enabled by `n', underflow traps are
enabled as well.
`su'
Like `su', but the instructions are marked to be safe for
software completion (see Alpha architecture manual for
details).
`sui'
Like `su', but inexact traps are enabled as well.
`-mfp-rounding-mode=ROUNDING MODE'
Selects the IEEE rounding mode. Other Alpha compilers call this
option `-fprm 'ROUNDING MODE. The ROUNDING MODE can be one of:
`n'
Normal IEEE rounding mode. Floating point numbers are
rounded towards the nearest machine number or towards the
even machine number in case of a tie.
`m'
Round towards minus infinity.
`c'
Chopped rounding mode. Floating point numbers are rounded
towards zero.
`d'
Dynamic rounding mode. A field in the floating point control
register (FPCR, see Alpha architecture reference manual)
controls the rounding mode in effect. The C library
initializes this register for rounding towards plus infinity.
Thus, unless your program modifies the FPCR, `d' corresponds
to round towards plus infinity.
`-mtrap-precision=TRAP PRECISION'
In the Alpha architecture, floating point traps are imprecise.
This means without software assistance it is impossible to recover
from a floating trap and program execution normally needs to be
terminated. GNU CC can generate code that can assist operating
system trap handlers in determining the exact location that caused
a floating point trap. Depending on the requirements of an
application, different levels of precisions can be selected:
`p'
Program precision. This option is the default and means a
trap handler can only identify which program caused a
floating point exception.
`f'
Function precision. The trap handler can determine the
function that caused a floating point exception.
`i'
Instruction precision. The trap handler can determine the
exact instruction that caused a floating point exception.
Other Alpha compilers provide the equivalent options called
`-scope_safe' and `-resumption_safe'.
`-mieee-conformant'
This option marks the generated code as IEEE conformant. You must
not use this option unless you also specify `-mtrap-precision=i'
and either `-mfp-trap-mode=su' or `-mfp-trap-mode=sui'. Its only
effect is to emit the line `.eflag 48' in the function prologue of
the generated assembly file. Under DEC Unix, this has the effect
that IEEE-conformant math library routines will be linked in.
`-mbuild-constants'
Normally GNU CC examines a 32- or 64-bit integer constant to see
if it can construct it from smaller constants in two or three
instructions. If it cannot, it will output the constant as a
literal and generate code to load it from the data segment at
runtime.
Use this option to require GNU CC to construct *all* integer
constants using code, even if it takes more instructions (the
maximum is six).
You would typically use this option to build a shared library
dynamic loader. Itself a shared library, it must relocate itself
in memory before it can find the variables and constants in its
own data segment.
`-malpha-as'
`-mgas'
Select whether to generate code to be assembled by the
vendor-supplied assembler (`-malpha-as') or by the GNU assembler
`-mgas'.
`-mbwx'
`-mno-bwx'
`-mcix'
`-mno-cix'
`-mmax'
`-mno-max'
Indicate whether GNU CC should generate code to use the optional
BWX, CIX, and MAX instruction sets. The default is to use the
instruction sets supported by the CPU type specified via `-mcpu='
option or that of the CPU on which GNU CC was built if none was
specified.
`-mcpu=CPU TYPE'
`-mcpu=CPU_TYPE'
Set the instruction set, register set, and instruction scheduling
parameters for machine type CPU_TYPE. You can specify either the
`EV' style name or the corresponding chip number. GNU CC supports
scheduling parameters for the EV4 and EV5 family of processors and
will choose the default values for the instruction set from the
processor you specify. If you do not specify a processor type,
GNU CC will default to the processor on which the compiler was
built.
Supported values for CPU_TYPE are
`ev4'
`21064'
Schedules as an EV4 and has no instruction set extensions.
`ev5'
`21164'
Schedules as an EV5 and has no instruction set extensions.
`ev56'
`21164a'
Schedules as an EV5 and supports the BWX extension.
`pca56'
`21164PC'
Schedules as an EV5 and supports the BWX and MAX extensions.
`ev6'
`21264'
Schedules as an EV5 (until Digital releases the scheduling
parameters for the EV6) and supports the BWX, CIX, and MAX
extensions.

File: gcc.info, Node: Clipper Options, Next: H8/300 Options, Prev: DEC Alpha Options, Up: Submodel Options
Clipper Options
---------------
These `-m' options are defined for the Clipper implementations:
`-mc300'
Produce code for a C300 Clipper processor. This is the default.
`-mc400'
Produce code for a C400 Clipper processor i.e. use floating point
registers f8..f15.

File: gcc.info, Node: H8/300 Options, Next: SH Options, Prev: Clipper Options, Up: Submodel Options
H8/300 Options
--------------
These `-m' options are defined for the H8/300 implementations:
`-mrelax'
Shorten some address references at link time, when possible; uses
the linker option `-relax'. *Note `ld' and the H8/300:
(ld.info)H8/300, for a fuller description.
`-mh'
Generate code for the H8/300H.
`-ms'
Generate code for the H8/S.
`-mint32'
Make `int' data 32 bits by default.
`-malign-300'
On the h8/300h, use the same alignment rules as for the h8/300.
The default for the h8/300h is to align longs and floats on 4 byte
boundaries. `-malign-300' causes them to be aligned on 2 byte
boundaries. This option has no effect on the h8/300.

File: gcc.info, Node: SH Options, Next: System V Options, Prev: H8/300 Options, Up: Submodel Options
SH Options
----------
These `-m' options are defined for the SH implementations:
`-m1'
Generate code for the SH1.
`-m2'
Generate code for the SH2.
`-m3'
Generate code for the SH3.
`-m3e'
Generate code for the SH3e.
`-mb'
Compile code for the processor in big endian mode.
`-ml'
Compile code for the processor in little endian mode.
`-mrelax'
Shorten some address references at link time, when possible; uses
the linker option `-relax'.

File: gcc.info, Node: System V Options, Next: V850 Options, Prev: SH Options, Up: Submodel Options
Options for System V
--------------------
These additional options are available on System V Release 4 for
compatibility with other compilers on those systems:
`-G'
Create a shared object. It is recommended that `-symbolic' or
`-shared' be used instead.
`-Qy'
Identify the versions of each tool used by the compiler, in a
`.ident' assembler directive in the output.
`-Qn'
Refrain from adding `.ident' directives to the output file (this is
the default).
`-YP,DIRS'
Search the directories DIRS, and no others, for libraries
specified with `-l'.
`-Ym,DIR'
Look in the directory DIR to find the M4 preprocessor. The
assembler uses this option.

File: gcc.info, Node: V850 Options, Prev: System V Options, Up: Submodel Options
V850 Options
------------
These `-m' options are defined for V850 implementations:
`-mlong-calls'
`-mno-long-calls'
Treat all calls as being far away (near). If calls are assumed to
be far away, the compiler will always load the functions address
up into a register, and call indirect through the pointer.
`-mno-ep'
`-mep'
Do not optimize (do optimize) basic blocks that use the same index
pointer 4 or more times to copy pointer into the `ep' register, and
use the shorter `sld' and `sst' instructions. The `-mep' option
is on by default if you optimize.
`-mno-prolog-function'
`-mprolog-function'
Do not use (do use) external functions to save and restore
registers at the prolog and epilog of a function. The external
functions are slower, but use less code space if more than one
function saves the same number of registers. The
`-mprolog-function' option is on by default if you optimize.
`-mspace'
Try to make the code as small as possible. At present, this just
turns on the `-mep' and `-mprolog-function' options.
`-mtda=N'
Put static or global variables whose size is N bytes or less into
the tiny data area that register `ep' points to. The tiny data
area can hold up to 256 bytes in total (128 bytes for byte
references).
`-msda=N'
Put static or global variables whose size is N bytes or less into
the small data area that register `gp' points to. The small data
area can hold up to 64 kilobytes.
`-mzda=N'
Put static or global variables whose size is N bytes or less into
the first 32 kilobytes of memory.
`-mv850'
Specify that the target processor is the V850.
`-mbig-switch'
Generate code suitable for big switch tables. Use this option
only if the assembler/linker complain about out of range branches
within a switch table.

File: gcc.info, Node: Code Gen Options, Next: Environment Variables, Prev: Submodel Options, Up: Invoking GCC
Options for Code Generation Conventions
=======================================
These machine-independent options control the interface conventions
used in code generation.
Most of them have both positive and negative forms; the negative form
of `-ffoo' would be `-fno-foo'. In the table below, only one of the
forms is listed--the one which is not the default. You can figure out
the other form by either removing `no-' or adding it.
`-fexceptions'
Enable exception handling, and generate extra code needed to
propagate exceptions. If you do not specify this option, GNU CC
enables it by default for languages like C++ that normally require
exception handling, and disabled for languages like C that do not
normally require it. However, when compiling C code that needs to
interoperate properly with exception handlers written in C++, you
may need to enable this option. You may also wish to disable this
option is you are compiling older C++ programs that don't use
exception handling.
`-fpcc-struct-return'
Return "short" `struct' and `union' values in memory like longer
ones, rather than in registers. This convention is less
efficient, but it has the advantage of allowing intercallability
between GNU CC-compiled files and files compiled with other
compilers.
The precise convention for returning structures in memory depends
on the target configuration macros.
Short structures and unions are those whose size and alignment
match that of some integer type.
`-freg-struct-return'
Use the convention that `struct' and `union' values are returned
in registers when possible. This is more efficient for small
structures than `-fpcc-struct-return'.
If you specify neither `-fpcc-struct-return' nor its contrary
`-freg-struct-return', GNU CC defaults to whichever convention is
standard for the target. If there is no standard convention, GNU
CC defaults to `-fpcc-struct-return', except on targets where GNU
CC is the principal compiler. In those cases, we can choose the
standard, and we chose the more efficient register return
alternative.
`-fshort-enums'
Allocate to an `enum' type only as many bytes as it needs for the
declared range of possible values. Specifically, the `enum' type
will be equivalent to the smallest integer type which has enough
room.
`-fshort-double'
Use the same size for `double' as for `float'.
`-fshared-data'
Requests that the data and non-`const' variables of this
compilation be shared data rather than private data. The
distinction makes sense only on certain operating systems, where
shared data is shared between processes running the same program,
while private data exists in one copy per process.
`-fno-common'
Allocate even uninitialized global variables in the bss section of
the object file, rather than generating them as common blocks.
This has the effect that if the same variable is declared (without
`extern') in two different compilations, you will get an error
when you link them. The only reason this might be useful is if
you wish to verify that the program will work on other systems
which always work this way.
`-fno-ident'
Ignore the `#ident' directive.
`-fno-gnu-linker'
Do not output global initializations (such as C++ constructors and
destructors) in the form used by the GNU linker (on systems where
the GNU linker is the standard method of handling them). Use this
option when you want to use a non-GNU linker, which also requires
using the `collect2' program to make sure the system linker
includes constructors and destructors. (`collect2' is included in
the GNU CC distribution.) For systems which *must* use
`collect2', the compiler driver `gcc' is configured to do this
automatically.
`-finhibit-size-directive'
Don't output a `.size' assembler directive, or anything else that
would cause trouble if the function is split in the middle, and the
two halves are placed at locations far apart in memory. This
option is used when compiling `crtstuff.c'; you should not need to
use it for anything else.
`-fverbose-asm'
Put extra commentary information in the generated assembly code to
make it more readable. This option is generally only of use to
those who actually need to read the generated assembly code
(perhaps while debugging the compiler itself).
`-fno-verbose-asm', the default, causes the extra information to
be omitted and is useful when comparing two assembler files.
`-fvolatile'
Consider all memory references through pointers to be volatile.
`-fvolatile-global'
Consider all memory references to extern and global data items to
be volatile.
`-fpic'
Generate position-independent code (PIC) suitable for use in a
shared library, if supported for the target machine. Such code
accesses all constant addresses through a global offset table
(GOT). The dynamic loader resolves the GOT entries when the
program starts (the dynamic loader is not part of GNU CC; it is
part of the operating system). If the GOT size for the linked
executable exceeds a machine-specific maximum size, you get an
error message from the linker indicating that `-fpic' does not
work; in that case, recompile with `-fPIC' instead. (These
maximums are 16k on the m88k, 8k on the Sparc, and 32k on the m68k
and RS/6000. The 386 has no such limit.)
Position-independent code requires special support, and therefore
works only on certain machines. For the 386, GNU CC supports PIC
for System V but not for the Sun 386i. Code generated for the IBM
RS/6000 is always position-independent.
`-fPIC'
If supported for the target machine, emit position-independent
code, suitable for dynamic linking and avoiding any limit on the
size of the global offset table. This option makes a difference
on the m68k, m88k, and the Sparc.
Position-independent code requires special support, and therefore
works only on certain machines.
`-ffixed-REG'
Treat the register named REG as a fixed register; generated code
should never refer to it (except perhaps as a stack pointer, frame
pointer or in some other fixed role).
REG must be the name of a register. The register names accepted
are machine-specific and are defined in the `REGISTER_NAMES' macro
in the machine description macro file.
This flag does not have a negative form, because it specifies a
three-way choice.
`-fcall-used-REG'
Treat the register named REG as an allocable register that is
clobbered by function calls. It may be allocated for temporaries
or variables that do not live across a call. Functions compiled
this way will not save and restore the register REG.
Use of this flag for a register that has a fixed pervasive role in
the machine's execution model, such as the stack pointer or frame
pointer, will produce disastrous results.
This flag does not have a negative form, because it specifies a
three-way choice.
`-fcall-saved-REG'
Treat the register named REG as an allocable register saved by
functions. It may be allocated even for temporaries or variables
that live across a call. Functions compiled this way will save
and restore the register REG if they use it.
Use of this flag for a register that has a fixed pervasive role in
the machine's execution model, such as the stack pointer or frame
pointer, will produce disastrous results.
A different sort of disaster will result from the use of this flag
for a register in which function values may be returned.
This flag does not have a negative form, because it specifies a
three-way choice.
`-fpack-struct'
Pack all structure members together without holes. Usually you
would not want to use this option, since it makes the code
suboptimal, and the offsets of structure members won't agree with
system libraries.
`-fcheck-memory-usage'
Generate extra code to check each memory access. GNU CC will
generate code that is suitable for a detector of bad memory
accesses such as `Checker'. If you specify this option, you can
not use the `asm' or `__asm__' keywords.
You must also specify this option when you compile functions you
call that have side effects. If you do not, you may get erroneous
messages from the detector. Normally, you should compile all
your code with this option. If you use functions from a library
that have side-effects (such as `read'), you may not be able to
recompile the library and specify this option. In that case, you
can enable the `-fprefix-function-name' option, which requests GNU
CC to encapsulate your code and make other functions look as if
they were compiled with `-fcheck-memory-usage'. This is done by
calling "stubs", which are provided by the detector. If you
cannot find or build stubs for every function you call, you may
have to specify `-fcheck-memory-usage' without
`-fprefix-function-name'.
`-fprefix-function-name'
Request GNU CC to add a prefix to the symbols generated for
function names. GNU CC adds a prefix to the names of functions
defined as well as functions called. Code compiled with this
option and code compiled without the option can't be linked
together, unless or stubs are used.
If you compile the following code with `-fprefix-function-name'
extern void bar (int);
void
foo (int a)
{
return bar (a + 5);
}
GNU CC will compile the code as if it was written:
extern void prefix_bar (int);
void
prefix_foo (int a)
{
return prefix_bar (a + 5);
}
This option is designed to be used with `-fcheck-memory-usage'.
`-fstack-check'
Generate code to verify that you do not go beyond the boundary of
the stack. You should specify this flag if you are running in an
environment with multiple threads, but only rarely need to specify
it in a single-threaded environment since stack overflow is
automatically detected on nearly all systems if there is only one
stack.
`+e0'
`+e1'
Control whether virtual function definitions in classes are used to
generate code, or only to define interfaces for their callers.
(C++ only).
These options are provided for compatibility with `cfront' 1.x
usage; the recommended alternative GNU C++ usage is in flux.
*Note Declarations and Definitions in One Header: C++ Interface.
With `+e0', virtual function definitions in classes are declared
`extern'; the declaration is used only as an interface
specification, not to generate code for the virtual functions (in
this compilation).
With `+e1', G++ actually generates the code implementing virtual
functions defined in the code, and makes them publicly visible.

File: gcc.info, Node: Environment Variables, Next: Running Protoize, Prev: Code Gen Options, Up: Invoking GCC
Environment Variables Affecting GNU CC
======================================
This section describes several environment variables that affect how
GNU CC operates. They work by specifying directories or prefixes to use
when searching for various kinds of files.
Note that you can also specify places to search using options such as
`-B', `-I' and `-L' (*note Directory Options::.). These take
precedence over places specified using environment variables, which in
turn take precedence over those specified by the configuration of GNU
CC. *Note Driver::.
`TMPDIR'
If `TMPDIR' is set, it specifies the directory to use for temporary
files. GNU CC uses temporary files to hold the output of one
stage of compilation which is to be used as input to the next
stage: for example, the output of the preprocessor, which is the
input to the compiler proper.
`GCC_EXEC_PREFIX'
If `GCC_EXEC_PREFIX' is set, it specifies a prefix to use in the
names of the subprograms executed by the compiler. No slash is
added when this prefix is combined with the name of a subprogram,
but you can specify a prefix that ends with a slash if you wish.
If GNU CC cannot find the subprogram using the specified prefix, it
tries looking in the usual places for the subprogram.
The default value of `GCC_EXEC_PREFIX' is `PREFIX/lib/gcc-lib/'
where PREFIX is the value of `prefix' when you ran the `configure'
script.
Other prefixes specified with `-B' take precedence over this
prefix.
This prefix is also used for finding files such as `crt0.o' that
are used for linking.
In addition, the prefix is used in an unusual way in finding the
directories to search for header files. For each of the standard
directories whose name normally begins with
`/usr/local/lib/gcc-lib' (more precisely, with the value of
`GCC_INCLUDE_DIR'), GNU CC tries replacing that beginning with the
specified prefix to produce an alternate directory name. Thus,
with `-Bfoo/', GNU CC will search `foo/bar' where it would
normally search `/usr/local/lib/bar'. These alternate directories
are searched first; the standard directories come next.
`COMPILER_PATH'
The value of `COMPILER_PATH' is a colon-separated list of
directories, much like `PATH'. GNU CC tries the directories thus
specified when searching for subprograms, if it can't find the
subprograms using `GCC_EXEC_PREFIX'.
`LIBRARY_PATH'
The value of `LIBRARY_PATH' is a colon-separated list of
directories, much like `PATH'. When configured as a native
compiler, GNU CC tries the directories thus specified when
searching for special linker files, if it can't find them using
`GCC_EXEC_PREFIX'. Linking using GNU CC also uses these
directories when searching for ordinary libraries for the `-l'
option (but directories specified with `-L' come first).
`C_INCLUDE_PATH'
`CPLUS_INCLUDE_PATH'
`OBJC_INCLUDE_PATH'
These environment variables pertain to particular languages. Each
variable's value is a colon-separated list of directories, much
like `PATH'. When GNU CC searches for header files, it tries the
directories listed in the variable for the language you are using,
after the directories specified with `-I' but before the standard
header file directories.
`DEPENDENCIES_OUTPUT'
If this variable is set, its value specifies how to output
dependencies for Make based on the header files processed by the
compiler. This output looks much like the output from the `-M'
option (*note Preprocessor Options::.), but it goes to a separate
file, and is in addition to the usual results of compilation.
The value of `DEPENDENCIES_OUTPUT' can be just a file name, in
which case the Make rules are written to that file, guessing the
target name from the source file name. Or the value can have the
form `FILE TARGET', in which case the rules are written to file
FILE using TARGET as the target name.

File: gcc.info, Node: Running Protoize, Prev: Environment Variables, Up: Invoking GCC
Running Protoize
================
The program `protoize' is an optional part of GNU C. You can use it
to add prototypes to a program, thus converting the program to ANSI C
in one respect. The companion program `unprotoize' does the reverse:
it removes argument types from any prototypes that are found.
When you run these programs, you must specify a set of source files
as command line arguments. The conversion programs start out by
compiling these files to see what functions they define. The
information gathered about a file FOO is saved in a file named `FOO.X'.
After scanning comes actual conversion. The specified files are all
eligible to be converted; any files they include (whether sources or
just headers) are eligible as well.
But not all the eligible files are converted. By default,
`protoize' and `unprotoize' convert only source and header files in the
current directory. You can specify additional directories whose files
should be converted with the `-d DIRECTORY' option. You can also
specify particular files to exclude with the `-x FILE' option. A file
is converted if it is eligible, its directory name matches one of the
specified directory names, and its name within the directory has not
been excluded.
Basic conversion with `protoize' consists of rewriting most function
definitions and function declarations to specify the types of the
arguments. The only ones not rewritten are those for varargs functions.
`protoize' optionally inserts prototype declarations at the
beginning of the source file, to make them available for any calls that
precede the function's definition. Or it can insert prototype
declarations with block scope in the blocks where undeclared functions
are called.
Basic conversion with `unprotoize' consists of rewriting most
function declarations to remove any argument types, and rewriting
function definitions to the old-style pre-ANSI form.
Both conversion programs print a warning for any function
declaration or definition that they can't convert. You can suppress
these warnings with `-q'.
The output from `protoize' or `unprotoize' replaces the original
source file. The original file is renamed to a name ending with
`.save'. If the `.save' file already exists, then the source file is
simply discarded.
`protoize' and `unprotoize' both depend on GNU CC itself to scan the
program and collect information about the functions it uses. So
neither of these programs will work until GNU CC is installed.
Here is a table of the options you can use with `protoize' and
`unprotoize'. Each option works with both programs unless otherwise
stated.
`-B DIRECTORY'
Look for the file `SYSCALLS.c.X' in DIRECTORY, instead of the
usual directory (normally `/usr/local/lib'). This file contains
prototype information about standard system functions. This option
applies only to `protoize'.
`-c COMPILATION-OPTIONS'
Use COMPILATION-OPTIONS as the options when running `gcc' to
produce the `.X' files. The special option `-aux-info' is always
passed in addition, to tell `gcc' to write a `.X' file.
Note that the compilation options must be given as a single
argument to `protoize' or `unprotoize'. If you want to specify
several `gcc' options, you must quote the entire set of
compilation options to make them a single word in the shell.
There are certain `gcc' arguments that you cannot use, because they
would produce the wrong kind of output. These include `-g', `-O',
`-c', `-S', and `-o' If you include these in the
COMPILATION-OPTIONS, they are ignored.
`-C'
Rename files to end in `.C' instead of `.c'. This is convenient
if you are converting a C program to C++. This option applies
only to `protoize'.
`-g'
Add explicit global declarations. This means inserting explicit
declarations at the beginning of each source file for each function
that is called in the file and was not declared. These
declarations precede the first function definition that contains a
call to an undeclared function. This option applies only to
`protoize'.
`-i STRING'
Indent old-style parameter declarations with the string STRING.
This option applies only to `protoize'.
`unprotoize' converts prototyped function definitions to old-style
function definitions, where the arguments are declared between the
argument list and the initial `{'. By default, `unprotoize' uses
five spaces as the indentation. If you want to indent with just
one space instead, use `-i " "'.
`-k'
Keep the `.X' files. Normally, they are deleted after conversion
is finished.
`-l'
Add explicit local declarations. `protoize' with `-l' inserts a
prototype declaration for each function in each block which calls
the function without any declaration. This option applies only to
`protoize'.
`-n'
Make no real changes. This mode just prints information about the
conversions that would have been done without `-n'.
`-N'
Make no `.save' files. The original files are simply deleted.
Use this option with caution.
`-p PROGRAM'
Use the program PROGRAM as the compiler. Normally, the name `gcc'
is used.
`-q'
Work quietly. Most warnings are suppressed.
`-v'
Print the version number, just like `-v' for `gcc'.
If you need special compiler options to compile one of your program's
source files, then you should generate that file's `.X' file specially,
by running `gcc' on that source file with the appropriate options and
the option `-aux-info'. Then run `protoize' on the entire set of
files. `protoize' will use the existing `.X' file because it is newer
than the source file. For example:
gcc -Dfoo=bar file1.c -aux-info
protoize *.c
You need to include the special files along with the rest in the
`protoize' command, even though their `.X' files already exist, because
otherwise they won't get converted.
*Note Protoize Caveats::, for more information on how to use
`protoize' successfully.