tccenv(5)

NAME

tccenv - Environments for tcc

DESCRIPTION

Tcc environments are used to configure the behaviour of tcc(1), a special case of which is specifying the APIs used. The standard environments supplied with the release are used to represent a number of commonly used APIs, implement certain tcc(1) command-line options, and provide a means of implementing system-specific options. User-defined environments can easily be written to correspond to a user-defined API, or to group together a number of tcc(1) command-line options into a single file.

An environment is just a file which is interpreted by tcc(1) when it is specified with the command-line option -Ystring, where string is the name of the file. Each environment file consists of lines of the form

*IDENTIFIER "text"

where IDENTIFIER is one of the environmental identifiers, text tells tcc(1) how to modify the value given by this identifier, and * stands for one of the environment prefixes + < and >.

USER-DEFINED ENVIRONMENTS

The simplest example of a user-defined environment contains lines of the form

+FLAG "text"

which tells tcc(1) to interpret text as if it were passed on the command-line. So, for example, an environment consisting of the lines

+FLAG "-Yposix"

+FLAG "-Xs"

+FLAG "-I/home/user/include"

will modify tcc(1) to use the POSIX 1003.1 API with strict checks, and add the directory /home/user/include to the search path for #included files.

By default, tcc(1) looks for environments in the current working directory and in the default environments directory. In addition, if the system variable TCCENV is defined, this specifies a colon-separated list of directories along which tcc(1) searches for any environment which is not a full pathname.

FULL ENVIRONMENT LIST

The majority of the standard environments can be divided into two classes: those which correspond to APIs and those which implement tcc(1) command-line options. (In addition to these, a small number are used to enable extra tools and to specify minimum integer sizes.)

The API environments are subdivided into base APIs (such as ANSI, POSIX) and extension APIs (such as the X11 environments):

ansi	the ANSI X3.159 API (this is the default API environment)
iso	the ISO/IEC 9899:1990 (Amendment 1:L1995 (E)) API
posix	the POSIX (IEEE 1003.1:1988) API
posix1	the POSIX.1 (ISO/IEC 9945-1:1990) API
posix2	the POSIX.2 (ISO/IEC 9945-2:1993) API
xpg3	the X/Open Portability Guide 3
xpg4	the X/Open Portability Guide 4
unix95	the X/Open Single UNIX Specification (Spec 1170)
svid3	the System V Interface Definition (3rd Edition)
aes	the Application Environment Specification (Revision A) API
bsd_extn	BSD-like extension for use with POSIX, etc.
x5_lib	X11 (Release 5) X Library
x5_t	X11 (Release 5) Intrinsics Toolkit
x5_mu	X11 (Release 5) Miscellaneous Utilities
x5_aw	X11 (Release 5) Athena Widgets
x5_mit	X11 (Release 5) MIT Implementation
x5_proto	X11 (Release 5) Protocol Extension
x5_ext	X11 (Release 5) Extensions
motif_1_1	Motif (Release 1.1)
motif_1_2	Motif (Release 1.2)
system	System headers as main API
system+	System headers as last resort extension API
tdf_ext	compilation using TDF Version 4.0 extensions

Some environments are available which modify access to previously specified APIs:

x5_private	permit access to X11 Release 5 private headers (*P.h)
motif_private	permit access to Motif private headers (*P.h)

Note that TDF token libraries for all these APIs will not be available on all platforms, so it may not be possible run installers for programs compiled with all API environments. It will always be possible to check code with any API environment using tchk(1).

The following environments are used to specify the use of particular tools (where available) which are not enabled by default:

c++	enables the C++ producer/checker tcpplus.
pl_tdf	enables the PL_TDF compiler pl.
tnc	enables the TDF notation compiler tnc.

The default behaviour of tcc(1) is to assume the minimal sizes of integer types allowed by ANSI. This behaviour can be modified with the following environments:

16bit	specifies minimal integer sizes allowed by ANSI (default)
32bit	specifies integer sizes found on most 32-bit machines

In addition to these, the following implement target-specific options:

aout	Use a.out instead of ELF format (386 Linux ELF only).
static	Use static instead of dynamic linking (Alpha only).

ENVIRONMENTAL IDENTIFIERS

In the following list, the environmental prefix * must be replaced by one of + (which replaces the existing value), < (which adds a value to the beginning of the existing list), or > (which adds a value to the end of the existing list).

SEE ALSO

tcc(1), tchk(1), tcpplus(1), pl(1), tnc(1).