LLVM has a documented mechanism for passing configuration information to
an out of tree project using CMake. See
https://llvm.org/docs/CMake.html#embedding-llvm-in-your-project.
Similar logic applies to "standalone" builds of other sub-projects
within LLVM that depend on each other. For example, a standalone build
of Flang will use this mechanism to acquire Clang's configuration.
Currently, the relevant CMake modules for Clang will only be copied into
the installation directory. This means that in order to configure a
standalone build of Flang, one has to first build and then install
Clang. This is not required for LLVM nor for MLIR - other sub-projects
that Flang depends on (i.e. the CMake modules for LLVM and MLIR are
available in the build dir, so installation is not needed).
This change removes the need for installing Clang in order to access its
configuration. It makes sure that the required CMake modules are copied
into the build directory. This will make Clang behave consistently with
LLVM and MLIR in this respect. It will also simplify building Flang as
standalone sub-project.
Differential Revision: https://reviews.llvm.org/D116731
See the docs in the new function for details.
I think I found every instance of this copy pasted code. Polly could
also use it, but currently does something different, so I will save the
behavior change for a future revision.
We get the shared, non-installed CMake modules following the pattern
established in D116472.
It might be good to have LLD and Flang also use this, but that would be
a functional change and so I leave it as future work.
Reviewed By: beanz, lebedev.ri
Differential Revision: https://reviews.llvm.org/D116521
LLVM's build system contains support for configuring a distribution, but
it can often be useful to be able to configure multiple distributions
(e.g. if you want separate distributions for the tools and the
libraries). Add this support to the build system, along with
documentation and usage examples.
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D89177
This makes sure that AddClang.cmake is installed alongside other Clang
CMake modules. This mirrors LLVM and MLIR in this respect and is
required when building the new Flang driver out of tree (as it depends
on Clang and includes AddClang.cmake).
Reviewed By: bogner
Differential Revision: https://reviews.llvm.org/D94533
Summary:
This change should fixes the export of CLANG_INCLUDE_DIRS variable in ClangConfig.cmake.
Unlike for the other variables, CLANG_INSTALL_PREFIX wasn't escaped meaning CLANG_INCLUDE_DIRS
resulting in the path "/include" instead of "${CLANG_INSTALL_PREFIX}/include".
Reviewers: beanz
Subscribers: mgorny
Differential Revision: https://reviews.llvm.org/D30911
llvm-svn: 298424
Include a path hint for find_package() in ClangConfig.cmake to ensure
that CMake prefers LLVM installed alongside clang over the default
search path.
If two versions of LLVM are installed in the system, and one of them is
in PATH, CMake's find_package() magic prefers the CMake directory
alongside that install by default. Adding a relative hint makes it
possible to prioritize to the install from which find_package() is
called.
If you want to build e.g. LLDB against another install of LLVM, you can
pass LLVM_CONFIG override. In this case, LLDB queries the prefix from
llvm-config and uses the CMake files located there. However, when
including ClangConfig, the implicit find_package() nevertheless prefers
PATH-found LLVM over the one used previously by LLDB, and two versions
of LLVMConfig end up being loaded.
This could be fixed on LLDB end up by explicitly forcing custom package
search location. However, it seems simpler and safer to add a hint to
ClangConfig than to track every usage of ClangConfig.
Differential Revision: https://reviews.llvm.org/D29304
llvm-svn: 293632
When using LLVM_DISTRIBUTION_COMPONENTS, it's possible for clang's
export list to be empty. If this happens the install(EXPORTS) command
will fail, but since there isn't anything to install anyway we really
just want to skip it.
llvm-svn: 286210
This ensures that the values do not bleed over in between computations. It may
make sense in the future to just refactor this code into functions to provide
"true scoping".
llvm-svn: 274179
This is an obvious bug since ClangConfig.cmake looks for ClangTargets.cmake in
${CMAKE_CURRENT_LIST_DIR}. But ClangTargets.cmake is in
${CMAKE_BINARY_DIR}/${CLANG_INSTALL_PACKAGE_DIR}, so it will always fail with an
in tree build.
In the case where clang is built out of tree, this is still correct since
CMAKE_BINARY_DIR and CLANG_BINARY_DIR will be the same.
llvm-svn: 274168
John Ericson