llvm.eclass

Name

llvm.eclass -- Utility functions to build against slotted LLVM

Description

The llvm.eclass provides utility functions that can be used to build against specific version of slotted LLVM (with fallback to :0 for old versions).

This eclass does not generate dependency strings. You need to write a proper dependency string yourself to guarantee that appropriate version of LLVM is installed.

Example use for a package supporting LLVM 9 to 11:

inherit cmake llvm

RDEPEND="
<sys-devel/llvm-11:=
|| (
      sys-devel/llvm:9
      sys-devel/llvm:10
      sys-devel/llvm:11
)
"
DEPEND=${RDEPEND}

LLVM_MAX_SLOT=11

# only if you need to define one explicitly
pkg_setup() {
llvm_pkg_setup
do-something-else
}

Example for a package needing LLVM+clang w/ a specific target:

inherit cmake llvm

# note: do not use := on both clang and llvm, it can match different
# slots then. clang pulls llvm in, so we can skip the latter.
RDEPEND="
>=sys-devel/clang-9:=[llvm_targets_AMDGPU(+)]
"
DEPEND=${RDEPEND}

llvm_check_deps() {
has_version -d "sys-devel/clang:${LLVM_SLOT}[llvm_targets_AMDGPU(+)]"
}

Supported EAPIs

6 7 8

Exported Phases

• pkg_setup

Functions

get_llvm_prefix [-b|-d] [<max_slot>]

Find the newest LLVM install that is acceptable for the package, and print an absolute path to it.

If -b is specified, the checks are performed relative to BROOT, and BROOT-path is returned. This is appropriate when your package calls llvm-config executable. -b is supported since EAPI 7.

If -d is specified, the checks are performed relative to ESYSROOT, and ESYSROOT-path is returned. This is appropriate when your package uses CMake find_package(LLVM). -d is the default.

If <max_slot> is specified, then only LLVM versions that are not newer than <max_slot> will be considered. Otherwise, all LLVM versions would be considered acceptable. The function does not support specifying minimal supported version -- the developer must ensure that a version new enough is installed via providing appropriate dependencies.

If llvm_check_deps() function is defined within the ebuild, it will be called to verify whether a particular slot is accepable. Within the function scope, LLVM_SLOT will be defined to the SLOT value (0, 4, 5...). The function should return a true status if the slot is acceptable, false otherwise. If llvm_check_deps() is not defined, the function defaults to checking whether sys-devel/llvm:${LLVM_SLOT} is installed.

llvm_pkg_setup

Prepend the appropriate executable directory for the newest acceptable LLVM slot to the PATH. For path determination logic, please see the get_llvm_prefix documentation.

The highest acceptable LLVM slot can be set in LLVM_MAX_SLOT variable. If it is unset or empty, any slot is acceptable.

The PATH manipulation is only done for source builds. The function is a no-op when installing a binary package.

If any other behavior is desired, the contents of the function should be inlined into the ebuild and modified as necessary.

Variables

LLVM_MAX_SLOT

Highest LLVM slot supported by the package. Needs to be set before llvm_pkg_setup is called. If unset, no upper bound is assumed.

Authors

Michał Górny <mgorny@gentoo.org>

Maintainers

Michał Górny <mgorny@gentoo.org>

Reporting Bugs

Please report bugs via https://bugs.gentoo.org/