Environment Variables
Gerbil uses a few environment variables, which affect the behaviour of the runtime and toolchain:
GERBIL_HOME
GERBIL_PATH
GERBIL_LOADPATH
GERBIL_HOME
This is the root of your Gerbil installation.
The runtime expects the gerbil system modules to be located in
$GERBIL_HOME/lib
, which is set as the first component of the runtime
load path. The compiler also expects to find system static compilation
artifacts there.
This variable must be set for dynamic executables to be able to load
the runtime. gxi
and gxc
can deduce it automatically from their
installation path if it's not set.
GERBIL_PATH
This is the root of your Gerbil workspace, which is the read-write
component of the system. If it's not set, then it defaults to ~/.gerbil
.
The runtime adds $GERBIL_PATH/lib
as the second component of the
runtime load path.
The toolchain uses $GERBIL_PATH
as default artifact output directory:
gxc
outputs compiled modules to$GERBIL_PATH/lib
, unless otherwise instructed.:std/make
outputs compiled modules to$GERBIL_PATH/lib
and binaries to$GERBIL_PATH/bin
, unless otherwise instructed.
GERBIL_LOADPATH
This is a colon separated list of directories to be appended to the runtime load path. You can use this for loading site specific libraries. By default it's unset, which is equivalent to an empty value.
GERBIL_GSC
This is the program name or path to the gsc
compiler executable;
defaults to gsc
(or to full path to gsc
, on a Nix build).
This variable is used by Gerbil v0.14-DEV-73-g7a2a91c1
and later; earlier versions
hardcode gsc
as the compiler program name.
GERBIL_GXC
This is the program name or path to the gxc
compiler executable;
defaults to gxc
(or to full path to gxc
, on a Nix build).
Currently it is only used by std/make
and std/build-script
,
and only when building software in parallel (which is now the default,
but can be disabled with the GERBIL_BUILD_CORES
variable below).
This variable is used by Gerbil v0.16-DEV-560
and later;
earlier versions did not have a parallel build.
GERBIL_BUILD_CORES
This is the number of cores that std/make
and std/build-script
will use
when building Gerbil programs, by spawning accordingly many compiler processes in parallel,
(mostly instances of gxc
, gsc
and gcc
).
If a parallel:
argument is provided to make
or defbuild-script
,
it will take precedence over this variable.
If no such argument is provided and the variable is undefined or invalid,
the number of cores present is auto-detected from the Operating System and used.
You can wholly disable parallelism by exporting GERBIL_BUILD_CORES=0
,
at which point the Gerbil part of compilation will be done in the current process.
By contrast, GERBIL_BUILD_CORES=1
enforces use of subprocesses for Gerbil compilation,
even though only one process will be run at once.
This variable is used by Gerbil v0.16-DEV-560
and later;
earlier versions did not have a parallel build.