8.17 Vala Support

Automake supports Vala (https://vala.dev/). Vala support requires the user to use GNU make.

foo_SOURCES = foo.vala bar.vala zardoz.c

Any .vala file listed in a _SOURCES variable will be compiled into C code by the Vala compiler. The generated .c files are distributed. The end user does not need to have a Vala compiler installed.

Because all C files must be generated, and the Vala compiler compiles all the .vala files for a target at once, it is not possible to add files to a _SOURCES variable that cannot be compiled together; for example, alternative platform-specific definitions of the same methods.

Automake ships with an Autoconf macro called AM_PROG_VALAC that will locate the Vala compiler and optionally check its version number.

Macro: AM_PROG_VALAC ([minimum-version], [action-if-found],

[action-if-not-found]) Search for a Vala compiler in PATH. If it is found, the variable VALAC is set to point to it (see below for more details). This macro takes three optional arguments. The first argument, if present, is the minimum version of the Vala API required to compile this package. For Vala releases, this is the same as the major and minor release number; e.g., when valac --version reports 0.48.7, valac --api-version reports 0.48. If a compiler is found and satisfies minimum-version, then action-if-found is run (this defaults to do nothing). Otherwise, action-if-not-found is run. If action-if-not-found is not specified, the default value is to print a warning in case no compiler is found, or if a too-old version of the compiler is found.

There are a few variables that are used when compiling Vala sources:

VALAC

Absolute path to the Vala compiler, or simply ‘valac’ if no suitable Vala compiler could be found at configure runtime.

VALAFLAGS

Additional arguments for the Vala compiler.

AM_VALAFLAGS

The maintainer’s variant of VALAFLAGS.

lib_LTLIBRARIES = libfoo.la
libfoo_la_SOURCES = foo.vala

Note that currently, you cannot use per-target *_VALAFLAGS (see Why are object files sometimes renamed?) to produce different C files from one Vala source file.