objc(1) UNIX System V (Oct 29, 1997) objc(1)
NAME
objc - Portable Object Compiler
SYNOPSIS
objc [ options ] file ...
DESCRIPTION
objc is a compiler for compiling Objective C objects into C,
or directly into a binary object file (by automatically
invoking an external C compiler).
Command line options that are not recognized by objc are
passed on to cc(1).
-boehm
The preferred interface to turn on garbage collection,
is to use the -gc flag (which currently is equivalent
to -boehm).
-boehm links against objcrtgc.a which is a version of
the runtime library, compiled with -DOBJCRT_BOEHM.
This option also adds the library gc.a (a mark-and-
sweep garbage collector, needs to be installed for this
option to work) to the list of libraries that are
automatically linked into the program.
-Bprefix
Use prefix as prefix for the bin, include and lib
directories when searching for binaries, include files
and libraries. The default prefix is set to the
installation directory (e.g. /usr/local). The
environment variable OBJCDIR overrides the default, and
this option can be used to override the value of the
environment variable, on the command line.
-c Produce a .o file but do not link. Equivalent to -Fo.
-C When used with the -E option, this option will
preserve comments in the preprocessed code. Otherwise,
this option is equivalent to -Fi, i.e. generate C code,
by translating Objective C into C, but do not run the C
compiler to produce a .o file.
-check
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Implemented for the binary driver objc.exe only.
Forces the driver to print a command whenever it is
supposed to invoke some tool using a system() call.
Commands are simply printed, they are not executed.
This is the default configuration of the Macintosh MPW
driver.
-cplus
Use the C++ compiler instead of the C compiler to
compile the output of objc1. The driver will
automatically select this mode objcpls1 for files
ending with a .cc or .mm suffix (C++ files or
Objective-C compiled by C++ respectively).
-cthreads
Link against the runtime library objcrtth.a which is a
thread-safe version of the objcrt.a runtime library
(compiled with -DOBJCRT_CTHREADS).
-dl Combine a number of object files into a dynamic
module, to be loaded by dlopen() or similar, into a
running Objective-C program. This option makes sure
the necessary code is generated to automatically
initialize Objective-C classes that are loaded into the
program.
-dollars
Passes flags to the C compiler to allow dollar
characters in identifiers. Only tested with GNU C.
-dynamic
Must be specified to link a program that will load
dynamic modules (modules that are built with -dl).
Attempts to link against objcrt.so and objpak.so shared
runtime libraries, if those libraries can be found.
-dynamic passes on -noShared to the stage 1 compiler
and registers the function _objcInitNoShared as runtime
initialization function. This is strictly speaking not
needed on UNIX, but essential when using DLLs on
Windows, so it is done on all platforms.
In addition, -dynamic causes on some platforms to link
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against the necessary libraries that define dynamic
linking functions. For example, on Linux it adds a
-rdynamic flag. On HP-UX it passes a -E flag to the
link editor. On Windows, (with the WATCOM driver), it
adds a -br flag to use the DLL versions of the WATCOM
runtime.
-E Preprocess input and write output to the stdout.
-Fletter
Stop at the compilation stage specified by letter.
Letter can be one of o (-Fo is equivalent to -c), or
other file suffixes such as i,c,j etc.
-gc Turn on garbage collection. Client programs compiled
with this flag use +new to allocate objects (as usual),
but do not have to send a -free message to destroy
objects.
-g Produce debugging symbols and attempts to link against
objcrt_g.a and objpak_g.a runtime libraries with debug
information, if they can be found. Since objc is also
emitting by default linetags that refer to the original
source file, it is possible to step through the code
using any C debugger.
-help
Print overview of compiler switches.
-i Generate a TDF capsule (.j file) for use with the tcc
compiler and do not link. Equivalent to -Fj.
-Idir
Add dir to the search path for include files.
-inlinecache
Generate inline cache code for calls to _imp()
messenger. The inline cache messenger associates to
each message expression its own cache, and will in many
cases bypass the default objcrt messenger.
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It is safe to use this option to produce binary
libraries of objects; the libraries can later be used
both from within programs that are compiled either with
or without the -inlinecache option.
-import
Pass flags to the C preprocessor to do the traditional
Objective-C constructs # import and // on which we
usually don't depend. Note that it's also possible to
set the environment variable CPP to a preprocessor
that's newline-terminated-comments capable, or to use
the cvtimport(1) utility so that the flag is not
needed.
-jfoo
Find and add a TDF library foo.tl.
-Jdir
Add dir to the search path for TDF libraries.
-lfoo
Find and add a library libfoo.a (or corresponding
shared library, depending on the system).
-Ldir
Add dir to the search path for libraries.
-main function
Emit runtime initialization code as first statement in
function. The default function name is main, but this
can be changed using this option if it's not desirable
for some reason to compile the main() function using
objc.
-mpwtool
Macintosh specific. Generates an MPW tool. Sets
creator type to the MPW type and adds the libraries
defined in the environment variable OBJCMPWLIBS.
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objc(1) UNIX System V (Oct 29, 1997) objc(1)-noBlocks
Define the preprocessor symbol OBJC_BLOCKS as 0 (by
default the symbol is defined as 1), and make the
parser refuse to parse Objective-C blocks. See the
documentation of the Block class for more information.
-noCache
Turn off global Objective C messenger cache. This
option can be used with -inlineCache. Sets the objcrt
variable noCacheFlag to 1. The program can selectively
turn on caching by setting the variable to 0.
-noI Do not search header files in the directories of the
runtime (objcrt) and of the collection class library
(objpak).
-noLibs
Do not link against the runtime (objcrt) and the
collection class library (objpak).
-noNilRcvr
Messages to nil, the NULL Object, are handled by the
nilHandler funtion. This option registers a handler
that aborts the process.
-noCategories
Do not allow (parse) categories. It is still possible
to use the method addMethodsTo: instead.
-noFiler
Do not automatically link the AsciiFiler into the
program. Do not automatically generate filer code for
class implementations. See the documentation on the
show, storeOn and readFrom methods, and the AsciiFiler
class, for more information.
-noFwd
Generate code for, and calls to, the traditional C
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messenger, _imp(), instead of calls to our forwarding C
messenger, fwdimp(). Programs compiled with -noFwd
compile faster and are significantly smaller in
executable size, but cannot make use of Object's
doesNotUnderstand: method. Libraries and object
files compiled with, or without, -noFwd can be freely
mixed, but message forwarding will only work for those
classes that were compiled with message forwarding
turned on.
-noPostlink
Allows to generate code for auto-init with compilers
that are configured to generate by default code for
postlink.
-noSelfAssign
Do not allow self as left hand side in an assignment.
This is related to the use of instance variables in
factory methods.
-noTags
Suppress generation of line tags in temporary files.
Normally, line tags as expected by the C compiler are
generated to indicate the line numbers of the original
source, so that diagnostics will be issued against the
Objective C source, not against the generated C output.
-nostdinc
Do not search header files in the standard include
directories. This option is system specific, i.e. must
be supported by the cpp(1) preprocessor that is being
used; it differs from the -noI option.
-O Enable the optimizer. Whether it is possible to
specify both -g and -O depends on the C compiler that
is being used.
-oneperfile
Allow only one class implementation per compilation
unit, as the original Stepstone compiler does. The
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compiler will generate slightly different structures
when this flag is used. The runtime is properly
initializing both code variants, and binary object
files compiled with or without this flag can be linked
into the same program.
-objc
Treat files ending with .c as Objective C source files.
Normally, files ending with a .m are assumed to be
Objective C files, and .c files are assumed to contain
plain C.
-otb Use object tables. This option causes the compiler to
generate code that uses a double indirection for Object
identifiers (handles, instead of pointers). It also
links against runtime libraries called otbcrt.a and
otbpak.a, because modules or libraries compiled with
the -otb switch cannot be mixed with modules that were
compiled without this option.
-pg Produce profiling information for use by gprof.
-pic Generate position independent code (PIC) on systems
that support it, for building shared libraries. On
some systems, this option translates to -fpic, on other
systems (e.g. HP-UX) it is equivalent to +z.
-ppi Include a set of compatibility header files in the
default include path (for compatibility with Stepstone
ICpak101). Also, allow classes to be defined using 3.x
Productivity Products International syntax. This is
used for compiling Brad Cox' Smalltalk to Objective-C
translator. Implementations of classes start with '='
instead of the usual @implementation keyword.
Superclasses still need to be declared with an
@interface part, but the class that is being defined,
itself, does not need an interface par t.
-postlink
Generate code for postlink. The default is not to do
this. If you compile with this option on, you cannot
combine object files for Objective C source with the
usual link editor ld. Instead, if you use -postlink,
you will be using our postlink (1) link editor
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processor, which does additional processing after
linking. Programs compiled with postlink use a
somewhat faster objcrt initialization, at the expense
of longer link times. Use the combination of the flags
-postlink and -retain to produce a file _postlnk.c that
contains a list of all the Objective C modules that are
linked into your program.
-prod
Combine target independent independent TDF capsules
into a TDF archive (a .ta file). This option is passed
on to the tcc (1) compiler, the archive name can be set
with -o. The resulting platform independent .ta file
can be specified on the command line as an ordinary .a
file.
-pthreads
Link against the library libpthreads.a and the runtime
library objcrtth.a which is a thread-safe version of
the objcrt.a runtime library (compiled with
-DOBJCRT_PTHREADS).
-quiet
Disable copyright notice. Same as -q.
-retain
Do not remove intermediate C files. Normally,
intermediate C code files are removed after objc has
made the C compiler compile them.
-refcnt
Generate code for reference counting. Assignments of
object variables are translated towards calls to the
idassign() function and code to increment and decrement
reference counts is emitted for each compound
statement. Only variables of type id are being
controlled by this option.
-sioux
Macintosh specific. Generates a SIOUX tool. Adds the
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libraries defined in the environment variable
OBJCSIOUXLIBS.
-static
On systems that support dynamic linking and the -static
compiler flag, this prevents linking with shared
libraries.
-Tprefix
Use prefix as prefix for temporary files (such as .P,
.c, .i files) that are generated by the precompiler.
For example, -T/scratch/ (note the trailing slash) will
place files in the /scratch directory. Alternatively,
the environment variable TMPDIR can be used to specify
the directory that should be used.
-undef
Undefine all built-in C preprocessor symbols. This
option is system specific, i.e. must be supported by
the cpp(1) preprocessor that is being used.
-unbuf
Run objc1 in unbuffered output mode. The default is to
use block buffering. Unbuffered output mode is useful
for debugging code generation of the precompiler.
-version
Print version of compiler and quit.
-v Print commands that are being executed by the driver
script. Same as -verbose.
-verbose
Print commands that are being executed by the driver
script. Equivalent to -v.
-w Suppress all warnings.
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objc(1) UNIX System V (Oct 29, 1997) objc(1)-Wletter,option
Add option to the list of options passed to the tool
identified by letter. Letter can be l for the link
editor, c for the C compiler, p for the C preprocessor,
or o for the stage 1 Objective C compiler. For
example, -Wp,-x passes the option -x to cc when it is
called with the -E flag to do preprocessing.
-wClassUsedAsType
Suppress warnings when class names are used as types.
The compiler will translate pointers to classnames to
"id".
-wUndefinedMethod
Suppress warnings for methods that are not prototyped.
The compiler will assume that the return value and
argument types of such methods is "id".
-Wall
Passed on the GNU C compiler for enabling compiler
warning messages.
-xstr strings
Run the (modified) BSD program xstr(1) after running
the Objective C compiler. This option can somewhat
reduce the size of Objective C selector tables of the
executable ( xstr will extract selector strings out of
the translated Objective C sources, assemble the
strings in a file called "strings", and will cause the
runtime to use a single, shared table of strings).
This could also speed up runtime initialization as
selectors don't have to be uniqued anylonger at
startup.
-Yenv
Use the specified environment. This is for the TenDRA
tcc compiler. Valid values are -Yansi, -Yposix,
-Yunix95 etc.
ENVIRONMENT
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The most useful environment variable for setting options for
objc is probably OBJCOPT. It was introduced in version
1.3.7 of the compiler (port to Windows95). The environment
variable OBJCDIR is kept for backward compatibility with
older compilers.
OBJCOPT
The environment variable OBJCOPT can hold a list of
options that is always prepended to the command line
arguments of objc.
For example, on UNIX, using the ksh shell :
export OBJCOPT="-q -B$HOME/objc1.1.1"
This would set the top location of the distribution,
and would, in addition, always suppress copyright
messages. On Windows95, the syntax is :
set OBJCOPT=-q -B\objc
OBJCDIR
This variable can hold the top location of the objc
distribution. For example:
for ksh: export OBJCDIR="$HOME/objc1.1.1"
for csh: setenv OBJCDIR "$HOME/objc1.1.1"
$OBJCDIR/bin and $OBJCDIR/man can be added to $PATH and
$MANPATH respectively.
OBJCPATHSEP
This environment variable, if set, is a string that
will be used as path separator instead of the default
separator. Applies to both objc and objc1.
TMPDIR
If set, temporary files will be placed in this
directory. The -T option overrides the value set by
TMPDIR.
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CC The environment variable CC can optionally hold the
name of a C compiler that is used to compile
intermediate C files.
CPP The environment variable CPP can optionally hold the
name of a C preprocessor that is used to preprocess
Objective-C input. The driver is normally configured
with a default value.
CPPFILTER
The environment variable CPPFILTER can optionally hold
the name of a C program that is to be ran after the C
preprocessor. The tool will be invoked with two
arguments : the name of the input file, and the name of
the output file.
OBJCRTMSG
This environment variable is not strictly related to
the compiler, but rather used by the runtime and hence,
by all Objective-C programs. It can be set to either
stderr or a filename to which messages should be
logged. For every message, class of the receiver and
name of the selector are printed on a line. This file
can quickly become very large; it is block buffered,
unless OBJCRTDBG is set, in which case it is line
buffered.
OBJCRTDBG
Like OBJCRTMSG, this variable is consulted by the
runtime. It can be set to either stderr or a filename
to which messages of the dbg() function should be
logged. If this variable is set, output for OBJCRTDBG
and OBJCRTMSG is line buffered.
BUGS
Send bug reports to objc-bugs@cys.de. Also see the
objc-users mailing list (subscribe by sending email to
objc-users-request@cys.de).
SEE ALSO
cc(1), postlink(1), cvtimport(1)
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