Recent patch that improved Flang's compatibility with respect to how LLVM
dynamic libraries should be linked (and specified in CMake recipes),
introduced a bug in the definition of `flang-new`:
* https://reviews.llvm.org/D87893
More specifically, `add_flang_tool` does not support the
`LINK_COMPONENTS` CMake argument. Instead, one should set
`LLVM_LINK_COMPONENTS` before calling `add_flang_tool`.
This patch reverts the change for `flang-new` from
https://reviews.llvm.org/D87893, and instead:
* sets `LLVM_LINK_COMPONENTS`
* calls `clang_target_link_libraries` to add Clang dependencies
Differential Revision: https://reviews.llvm.org/D89403
Harmonize usage of LLVM components througout Flang.
Explicit LLVM Libs where used across several CMakeFIles, which led to
incompatibilities with LLVM shlibs.
Fortunately, the LLVM component system can be relied on to harmoniously handle
both cases.
Differential Revision: https://reviews.llvm.org/D87893
`flang-new` depends on libclangFrontend (it uses DiagnosticConsumer
classes from there). This patch adds the missing dependency in CMake.
clang::TextDiagnosticBuffer is only reported as missing when compiling
`flang-new` with BUILD_SHARED_LIBS=ON. This symbol is linked in
statically with libflangFrontend when BUILD_SHARED_LIBS=OFF.
Summary:
This is the first patch implementing the new Flang driver as outlined in [1],
[2] & [3]. It creates Flang driver (`flang-new`) and Flang frontend driver
(`flang-new -fc1`). These will be renamed as `flang` and `flang -fc1` once the
current Flang throwaway driver, `flang`, can be replaced with `flang-new`.
Currently only 2 options are supported: `-help` and `--version`.
`flang-new` is implemented in terms of libclangDriver, defaulting the driver
mode to `FlangMode` (added to libclangDriver in [4]). This ensures that the
driver runs in Flang mode regardless of the name of the binary inferred from
argv[0].
The design of the new Flang compiler and frontend drivers is inspired by it
counterparts in Clang [3]. Currently, the new Flang compiler and frontend
drivers re-use Clang libraries: clangBasic, clangDriver and clangFrontend.
To identify Flang options, this patch adds FlangOption/FC1Option enums.
Driver::printHelp is updated so that `flang-new` prints only Flang options.
The new Flang driver is disabled by default. To enable it, set
`-DBUILD_FLANG_NEW_DRIVER=ON` when configuring CMake and add clang to
`LLVM_ENABLE_PROJECTS` (e.g. -DLLVM_ENABLE_PROJECTS=“clang;flang;mlir”).
[1] “RFC: new Flang driver - next steps”
http://lists.llvm.org/pipermail/flang-dev/2020-July/000470.html
[2] “RFC: Adding a fortran mode to the clang driver for flang”
http://lists.llvm.org/pipermail/cfe-dev/2019-June/062669.html
[3] “RFC: refactoring libclangDriver/libclangFrontend to share with Flang”
http://lists.llvm.org/pipermail/cfe-dev/2020-July/066393.html
[4] https://reviews.llvm.org/rG6bf55804924d5a1d902925ad080b1a2b57c5c75c
co-authored-by: Andrzej Warzynski <andrzej.warzynski@arm.com>
Reviewed By: richard.barton.arm, sameeranjoshi
Differential Revision: https://reviews.llvm.org/D86089
Andrzej Warzynski