[flang] Add fir-lsp-server (llvm#114059)

This patch adds a fir-lsp-server tool for editor support for editing fir
files, using the existing MLIR lsp server support.

See https://mlir.llvm.org/docs/Tools/MLIRLSP/ for more information.

flang/tools/CMakeLists.txt

@@ -12,3 +12,4 @@ add_subdirectory(flang-driver)
 add_subdirectory(tco)
 add_subdirectory(f18-parse-demo)
 add_subdirectory(fir-opt)
+add_subdirectory(fir-lsp-server)

flang/tools/fir-lsp-server/CMakeLists.txt

@@ -0,0 +1,17 @@
+set(LLVM_LINK_COMPONENTS
+  Core
+  Support
+  AsmParser
+  )
+
+add_flang_tool(fir-lsp-server fir-lsp-server.cpp)
+
+get_property(dialect_libs GLOBAL PROPERTY MLIR_DIALECT_LIBS)
+get_property(extension_libs GLOBAL PROPERTY MLIR_EXTENSION_LIBS)
+target_link_libraries(fir-lsp-server PRIVATE
+  CUFDialect
+  FIRDialect
+  HLFIRDialect
+  MLIRLspServerLib
+  ${dialect_libs}
+  ${extension_libs})

flang/tools/fir-lsp-server/fir-lsp-server.cpp

@@ -0,0 +1,9 @@
+#include "mlir/Tools/mlir-lsp-server/MlirLspServerMain.h"
+#include "flang/Optimizer/Support/InitFIR.h"
+
+int main(int argc, char **argv) {
+  mlir::DialectRegistry registry;
+  fir::support::registerNonCodegenDialects(registry);
+  fir::support::addFIRExtensions(registry);
+  return mlir::failed(mlir::MlirLspServerMain(argc, argv, registry));
+}