GNU Compiler Collection (GCC) Internals
5.3.8.2 The Front End `config-lang.in' File
Each language subdirectory contains a `config-lang.in' file.
This file is a shell script that may define some variables describing
the language:
language
- This definition must be present, and gives the name of the language
for some purposes such as arguments to `--enable-languages'.
lang_requires
- If defined, this variable lists (space-separated) language front ends
other than C that this front end requires to be enabled (with the
names given being their
language settings). For example, the
Java front end depends on the C++ front end, so sets
`lang_requires=c++'.
target_libs
- If defined, this variable lists (space-separated) targets in the top
level `Makefile' to build the runtime libraries for this
language, such as
target-libobjc.
lang_dirs
- If defined, this variable lists (space-separated) top level
directories (parallel to `gcc'), apart from the runtime libraries,
that should not be configured if this front end is not built.
build_by_default
- If defined to `no', this language front end is not built unless
enabled in a `--enable-languages' argument. Otherwise, front
ends are built by default, subject to any special logic in
`configure.in' (as is present to disable the Ada front end if the
Ada compiler is not already installed).
boot_language
- If defined to `yes', this front end is built in stage 1 of the
bootstrap. This is only relevant to front ends written in their own
languages.
compilers
- If defined, a space-separated list of compiler executables that should
be installed in `libsubdir'. The names here will each end
with `\$(exeext)'.
stagestuff
- If defined, a space-separated list of files that should be moved to
the `stagen' directories in each stage of bootstrap.
outputs
- If defined, a space-separated list of files that should be generated
by `configure' substituting values in them. This mechanism can
be used to create a file `language/Makefile' from
`language/Makefile.in', but this is deprecated, building
everything from the single `gcc/Makefile' is preferred.
