The c99 utility is an interface to the standard C compilation
system; it shall accept source code conforming to the
ISO C standard. The system conceptually consists of a compiler and
link editor. The files referenced by operands shall
be compiled and linked to produce an executable file. (It is unspecified
whether the linking occurs entirely within the operation
of c99; some implementations may produce objects that are not
fully resolved until the file is executed.)
If the -c option is specified, for all pathname operands of
the form file.c, the files:
$(basenamepathname.c).o
shall be created as the result of successful compilation. If the -c
option is not specified, it is unspecified whether
such .o files are created or deleted for the file.c
operands.
If there are no options that prevent link editing (such as -c
or -E), and all operands compile and link without
error, the resulting executable file shall be written according to
the -ooutfile option (if present) or to the file
a.out.
The executable file shall be created as specified in File Read,
Write, and
Creation , except that the file permission bits shall be set to:
S_IRWXO | S_IRWXG | S_IRWXU
and the bits specified by the umask of the process shall be
cleared.
The c99 utility shall conform to the Base Definitions volume
of IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines,
except that:
*
The -llibrary operands have the format of options, but
their position within a list of operands affects the order
in which libraries are searched.
*
The order of specifying the -I and -L options is significant.
*
Conforming applications shall specify each option separately; that
is, grouping option letters (for example, -cO) need
not be recognized by all implementations.
The following options shall be supported:
-c
Suppress the link-edit phase of the compilation, and do not remove
any object files that are produced.
-g
Produce symbolic information in the object or executable files; the
nature of this information is unspecified, and may be
modified by implementation-defined interactions with other options.
-s
Produce object or executable files, or both, from which symbolic and
other information not required for proper execution using
the exec family defined in the System Interfaces volume of IEEE Std 1003.1-2001
has been removed (stripped). If
both -g and -s options are present, the action taken is
unspecified.
-o outfile
Use the pathname outfile, instead of the default a.out,
for the executable file produced. If the -o option
is present with -c or -E, the result is unspecified.
-D name[=value]
Define name as if by a C-language #define directive. If
no = value is given, a value of 1 shall be used. The
-D option has lower precedence than the -U option. That
is, if name is used in both a -U and a
-D option, name shall be undefined regardless of the order
of the options. Additional implementation-defined
names may be provided by the compiler. Implementations shall
support at least 2048 bytes of -D definitions and 256
names.
-E
Copy C-language source files to standard output, expanding all preprocessor
directives; no compilation shall be performed. If
any operand is not a text file, the effects are unspecified.
-I directory
Change the algorithm for searching for headers whose names are not
absolute pathnames to look in the directory named by the
directory pathname before looking in the usual places. Thus,
headers whose names are enclosed in double-quotes ( ""
) shall be searched for first in the directory of the file with the
#include line, then in directories named in -I
options, and last in the usual places. For headers whose names are
enclosed in angle brackets ( "<>" ), the header
shall be searched for only in directories named in -I options
and then in the usual places. Directories named in -I
options shall be searched in the order specified. Implementations
shall support at least ten instances of this option in a single
c99 command invocation.
-L directory
Change the algorithm of searching for the libraries named in the -l
objects to look in the directory named by the
directory pathname before looking in the usual places. Directories
named in -L options shall be searched in the order
specified. Implementations shall support at least ten instances of
this option in a single c99 command invocation. If a
directory specified by a -L option contains files named libc.a,
libm.a, libl.a, or liby.a, the
results are unspecified.
-O optlevel
Specify the level of code optimization. If the optlevel option-argument
is the digit ’0’ , all special code
optimizations shall be disabled. If it is the digit ’1’ , the
nature of the optimization is unspecified. If the -O
option is omitted, the nature of the system’s default optimization
is unspecified. It is unspecified whether code generated in the
presence of the -O 0 option is the same as that generated when
-O is omitted. Other optlevel values may be
supported.
-U name
Remove any initial definition of name.
Multiple instances of the -D, -I, -U, and -L
options can be specified.
An operand is either in the form of a pathname or the form -llibrary. The application shall ensure that at
least one operand of the pathname form is specified. The following
operands shall be supported:
file.c
A C-language source file to be compiled and optionally linked. The
application shall ensure that the operand is of this form if
the -c option is used.
file.a
A library of object files typically produced by the ar utility,
and passed directly
to the link editor. Implementations may recognize implementation-defined
suffixes other than .a as denoting object file
libraries.
file.o
An object file produced by c99-c and passed directly
to the link editor. Implementations may recognize
implementation-defined suffixes other than .o as denoting object
files.
The processing of other files is implementation-defined.
-l library
(The letter ell.) Search the library named:
liblibrary.a
A library shall be searched when its name is encountered, so the placement
of a -l operand is significant. Several
standard libraries can be specified in this manner, as described in
the EXTENDED DESCRIPTION section. Implementations may recognize
implementation-defined suffixes other than .a as denoting libraries.
The input file shall be one of the following: a text file containing
a C-language source program, an object file in the format
produced by c99-c, or a library of object files, in the
format produced by archiving zero or more object files,
using ar. Implementations may supply additional utilities that
produce files in these
formats. Additional input file formats are implementation-defined.
The following environment variables shall affect the execution of
c99:
LANG
Provide a default value for the internationalization variables that
are unset or null. (See the Base Definitions volume of
IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables
for
the precedence of internationalization variables used to determine
the values of locale categories.)
LC_ALL
If set to a non-empty string value, override the values of all the
other internationalization variables.
LC_CTYPE
Determine the locale for the interpretation of sequences of bytes
of text data as characters (for example, single-byte as
opposed to multi-byte characters in arguments and input files).
LC_MESSAGES
Determine the locale that should be used to affect the format and
contents of diagnostic messages written to standard
error.
NLSPATH
Determine the location of message catalogs for the processing of LC_MESSAGES
.
TMPDIR
Provide a pathname that should override the default directory for
temporary files, if any. On
XSI-conforming systems, provide a pathname that shall override the
default directory for temporary files, if any.
If more than one file operand ending in .c (or possibly
other unspecified suffixes) is given, for each such
file:
"%s:\n", <file>
may be written. These messages, if written, shall precede the processing
of each input file; they shall not be written to the
standard output if they are written to the standard error, as described
in the STDERR section.
If the -E option is specified, the standard output shall be
a text file that represents the results of the preprocessing
stage of the language; it may contain extra information appropriate
for subsequent compilation passes.
The standard error shall be used only for diagnostic messages. If
more than one file operand ending in .c (or
possibly other unspecified suffixes) is given, for each such file:
"%s:\n", <file>
may be written to allow identification of the diagnostic and warning
messages with the appropriate input file. These messages,
if written, shall precede the processing of each input file; they
shall not be written to the standard error if they are written to
the standard output, as described in the STDOUT section.
This utility may produce warning messages about certain conditions
that do not warrant returning an error (non-zero) exit
value.
The c99 utility shall recognize the following -l operands
for standard libraries:
-l c
This operand shall make visible all functions referenced in the System
Interfaces volume of IEEE Std 1003.1-2001,
with the possible exception of those functions listed as residing
in <aio.h>, <arpa/inet.h>, <complex.h>, <fenv.h>,
<math.h>, <mqueue.h>, <netdb.h>, <netinet/in.h>,
<pthread.h>, <sched.h>, <semaphore.h>, <spawn.h>,
<sys/socket.h>, pthread_kill(), and pthread_sigmask()
in <signal.h>, <trace.h>, functions
marked as extensions other than as part of the MF or MPR extensions
in <sys/mman.h>, functions marked as ADV in <fcntl.h>,
and functions marked as CS, CPT, and TMR in <time.h>. This operand
shall not be required to be present to cause a search of this
library.
-l l
This operand shall make visible all functions required by the C-language
output of lex that are not made available through the -l c
operand.
-l pthread
This operand shall make visible all functions referenced in <pthread.h>
and pthread_kill() and pthread_sigmask() referenced in
<signal.h>. An implementation may search this library in the
absence of this
operand.
-l m
This operand shall make visible all functions referenced in <math.h>,
<complex.h>, and <fenv.h>. An
implementation may search this library in the absence of this operand.
-l rt
This operand shall make visible all functions referenced in <aio.h>,
<mqueue.h>, <sched.h>, <semaphore.h>, and <spawn.h>,
functions marked as extensions other than as part of the MF or MPR
extensions in <sys/mman.h>, functions marked as ADV in <fcntl.h>,
and functions marked as CS, CPT, and TMR in <time.h>. An implementation
may search this library in the absence of this operand.
-l trace
This operand shall make visible all functions referenced in <trace.h>.
An
implementation may search this library in the absence of this operand.
-l xnet
This operand makes visible all functions referenced in <arpa/inet.h>,
<netdb.h>, <netinet/in.h>, and <sys/socket.h>. An
implementation may search this library in the absence of this
operand.
-l y
This operand shall make visible all functions required by the C-language
output of yacc that are not made available through the -l c
operand.
In the absence of options that inhibit invocation of the link editor,
such as -c or -E, the c99 utility
shall cause the equivalent of a -l c operand to be passed to
the link editor as the last -l operand, causing it
to be searched after all other object files and libraries are loaded.
It is unspecified whether the libraries libc.a, libm.a,
librt.a, libpthread.a, libl.a,
liby.a, or libxnet.a exist as regular files. The implementation
may accept as -l operands names of objects
that do not exist as regular files.
The C compiler and link editor shall support the significance of external
symbols up to a length of at least 31 bytes; the
action taken upon encountering symbols exceeding the implementation-defined
maximum symbol length is unspecified.
The compiler and link editor shall support a minimum of 511 external
symbols per source or object file, and a minimum of 4095
external symbols in total. A diagnostic message shall be written to
the standard output if the implementation-defined limit is
exceeded; other actions are unspecified.
All implementations shall support one of the following programming
environments as a default. Implementations may support more
than one of the following programming environments. Applications can
use sysconf()
or getconf to determine which programming environments are supported.
Table: Programming Environments: Type Sizes
Programming Environment
Bits in
Bits in
Bits in
Bits in
getconf Name
int
long
pointer
off_t
_POSIX_V6_ILP32_OFF32
32
32
32
32
_POSIX_V6_ILP32_OFFBIG
32
32
32
>=64
_POSIX_V6_LP64_OFF64
32
64
64
64
_POSIX_V6_LPBIG_OFFBIG
>=32
>=64
>=64
>=64
All implementations shall support one or more environments where the
widths of the following types are no greater than the width
of type long:
blksize_t, cc_t, mode_t, nfds_t, pid_t,
ptrdiff_t, size_t,
speed_t, ssize_t, suseconds_t, tcflag_t, useconds_t,
wchar_t, wint_t
The executable files created when these environments are selected
shall be in a proper format for execution by the exec
family of functions. Each environment may be one of the ones in Programming
Environments: Type Sizes , or
it may be another environment. The names for the environments that
meet this requirement shall be output by a getconf command using
the _POSIX_V6_WIDTH_RESTRICTED_ENVS argument. If more than one
environment meets the requirement, the names of all such environments
shall be output on separate lines. Any of these names can
then be used in a subsequent getconf command to obtain the flags
specific to that
environment with the following suffixes added as appropriate:
_CFLAGS
To get the C compiler flags.
_LDFLAGS
To get the linker/loader flags.
_LIBS
To get the libraries.
This requirement may be removed in a future version of IEEE Std 1003.1.
When this utility processes a file containing a function called main(),
it shall be defined with a return type equivalent
to int. Using return from the initial call to main() shall
be equivalent (other than with respect to language scope
issues) to calling exit() with the returned value. Reaching
the end of the initial call
to main() shall be equivalent to calling exit(0). The
implementation shall not declare a prototype for this
function.
Implementations provide configuration strings for C compiler flags,
linker/loader flags, and libraries for each supported
environment. When an application needs to use a specific programming
environment rather than the implementation default programming
environment while compiling, the application shall first verify that
the implementation supports the desired environment. If the
desired programming environment is supported, the application shall
then invoke c99 with the appropriate C compiler flags as
the first options for the compile, the appropriate linker/loader flags
after any other options but before any operands, and the
appropriate libraries at the end of the operands.
Conforming applications shall not attempt to link together object
files compiled for different programming models. Applications
shall also be aware that binary data placed in shared memory or in
files might not be recognized by applications built for other
programming models.
Table: Programming Environments: c99 and cc Arguments
When c99 encounters a compilation error that causes an object
file not to be created, it shall write a diagnostic to
standard error and continue to compile other source code operands,
but it shall not perform the link phase and return a non-zero
exit status. If the link edit is unsuccessful, a diagnostic message
shall be written to standard error and c99 exits with a
non-zero status. A conforming application shall rely on the exit status
of c99, rather than on the existence or mode of the
executable file.
Since the c99 utility usually creates files in the current directory
during the compilation process, it is typically
necessary to run the c99 utility in a directory in which a file
can be created.
On systems providing POSIX Conformance (see the Base Definitions volume
of IEEE Std 1003.1-2001, Chapter 2, Conformance), c99 is required
only with the C-Language Development
option; XSI-conformant systems always provide c99.
Some historical implementations have created .o files when -c
is not specified and more than one source file is
given. Since this area is left unspecified, the application cannot
rely on .o files being created, but it also must be
prepared for any related .o files that already exist being deleted
at the completion of the link edit.
Some historical implementations have permitted -L options to
be interspersed with -l operands on the command line.
For an application to compile consistently on systems that do not
behave like this, it is necessary for a conforming application to
supply all -L options before any of the -l options.
There is the possible implication that if a user supplies versions
of the standard functions (before they would be encountered
by an implicit -l c or explicit -l m), that those versions
would be used in place of the standard versions.
There are various reasons this might not be true (functions defined
as macros, manipulations for clean name space, and so on), so
the existence of files named in the same manner as the standard libraries
within the -L directories is explicitly stated to
produce unspecified behavior.
All of the functions specified in the System Interfaces volume of
IEEE Std 1003.1-2001 may be made visible by
implementations when the Standard C Library is searched. Conforming
applications must explicitly request searching the other
standard libraries when functions made visible by those libraries
are used.
The following usage example compiles foo.c and creates the executable
file foo:
c99 -o foo foo.c
The following usage example compiles foo.c and creates the object
file foo.o:
c99 -c foo.c
The following usage example compiles foo.c and creates the executable
file a.out:
c99 foo.c
The following usage example compiles foo.c, links it with bar.o,
and creates the executable file a.out. It
may also create and leave foo.o:
c99 foo.c bar.o
2.
The following example shows how an application using threads interfaces
can test for support of and use a programming
environment supporting 32-bit int, long, and pointer
types and an off_t type using at least 64
bits:
if [ $(getconf _POSIX_V6_ILP32_OFFBIG) != "-1" ]
then
c99 $(getconf POSIX_V6_ILP32_OFFBIG_CFLAGS) -D_XOPEN_SOURCE=600 \
$(getconf POSIX_V6_ILP32_OFFBIG_LDFLAGS) foo.c -o foo \
$(getconf POSIX_V6_ILP32_OFFBIG_LIBS) -l pthread
else
echo ILP32_OFFBIG programming environment not supported
exit 1
fi
3.
The following examples clarify the use and interactions of -L
options and -l operands.
Consider the case in which module a.c calls function f()
in library libQ.a, and module b.c calls
function g() in library libp.a. Assume that both libraries
reside in /a/b/c. The command line to compile and
link in the desired way is:
c99 -L /a/b/c main.o a.c -l Q b.c -l p
In this case the -l Q operand need only precede the first -l p
operand, since both libQ.a and
libp.a reside in the same directory.
Multiple -L operands can be used when library name collisions
occur. Building on the previous example, suppose that the
user wants to use a new libp.a, in /a/a/a, but still wants
f() from /a/b/c/libQ.a:
c99 -L /a/a/a -L /a/b/c main.o a.c -l Q b.c -l p
In this example, the linker searches the -L options in the order
specified, and finds /a/a/a/libp.a before
/a/b/c/libp.a when resolving references for b.c. The order
of the -l operands is still important, however.
4.
The following example shows how an application can use a programming
environment where the widths of the following types:
blksize_t, cc_t, mode_t, nfds_t, pid_t,
ptrdiff_t, size_t,
speed_t, ssize_t, suseconds_t, tcflag_t, useconds_t,
wchar_t, wint_t
are no greater than the width of type long:
# First choose one of the listed environments ...
# ... if there are no additional constraints, the first one will do:
CENV=$(getconf _POSIX_V6_WIDTH_RESTRICTED_ENVS | head -n l)
# ... or, if an environment that supports large files is preferred,
# look for names that contain "OFF64" or "OFFBIG". (This chooses
# the last one in the list if none match.)
for CENV in $(getconf _POSIX_V6_WIDTH_RESTRICTED_ENVS)
do
case $CENV in
*OFF64*|*OFFBIG*) break ;;
esac
done
# The chosen environment name can now be used like this:
The c99 utility is based on the c89 utility originally
introduced in the ISO POSIX-2:1993 standard.
Some of the changes from c89 include the modification to the
contents of the Standard Libraries section to account for
new headers and options; for example, <spawn.h> added to the
-l rt
operand, and the -l trace operand added for the Tracing functions.
File Read, Write, and Creation , ar , getconf ,
make , nm , strip , umask() , the System Interfaces
volume of
IEEE Std 1003.1-2001, exec, sysconf(), the Base Definitions
volume
of IEEE Std 1003.1-2001, Chapter 13, Headers
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
IEEE/The Open Group
C99 (P)
2003
Generated by OpenAsthra.com from man1p/c99.1p using man macros with tbl support.
