[CIR] Move CIR dialect from mlir to clang

This was discussed as part of the RFC and since we are going to
require some AST presence in CIR soon, implement the dialect move
sooner than later.

Author: bcardosolopes

clang/include/clang/CIR/CMakeLists.txt

@@ -3,4 +3,4 @@ set(MLIR_TABLEGEN_OUTPUT_DIR ${CMAKE_BINARY_DIR}/tools/mlir/include)
 include_directories(${MLIR_INCLUDE_DIR})
 include_directories(${MLIR_TABLEGEN_OUTPUT_DIR})
 
-# add_subdirectory(Dialect)
+add_subdirectory(Dialect)

clang/include/clang/CIR/Dialect/CMakeLists.txt

@@ -0,0 +1,35 @@
+set(MLIR_MAIN_SRC_DIR ${LLVM_MAIN_SRC_DIR}/../mlir/include ) # --src-root
+set(MLIR_INCLUDE_DIR ${LLVM_MAIN_SRC_DIR}/../mlir/include ) # --includedir
+set(MLIR_TABLEGEN_OUTPUT_DIR ${CMAKE_BINARY_DIR}/tools/mlir/include)
+set(MLIR_TABLEGEN_EXE $<TARGET_FILE:mlir-tblgen>)
+include_directories(SYSTEM ${MLIR_INCLUDE_DIR})
+include_directories(SYSTEM ${MLIR_TABLEGEN_OUTPUT_DIR})
+
+add_custom_target(clang-cir-doc)
+
+# This replicates part of the add_mlir_doc cmake function from MLIR that cannot
+# be used here. This happens because it expects to be run inside MLIR directory
+# which is not the case for CIR (and also FIR, both have similar workarounds).
+function(add_clang_mlir_doc doc_filename output_file output_directory command)
+  set(LLVM_TARGET_DEFINITIONS ${doc_filename}.td)
+  tablegen(MLIR ${output_file}.md ${command} ${ARGN} "-I${MLIR_MAIN_SRC_DIR}" "-I${MLIR_INCLUDE_DIR}")
+  set(GEN_DOC_FILE ${MLIR_BINARY_DIR}/docs/${output_directory}${output_file}.md)
+  add_custom_command(
+          OUTPUT ${GEN_DOC_FILE}
+          COMMAND ${CMAKE_COMMAND} -E copy
+                  ${CMAKE_CURRENT_BINARY_DIR}/${output_file}.md
+                  ${GEN_DOC_FILE}
+          DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${output_file}.md)
+  add_custom_target(${output_file}DocGen DEPENDS ${GEN_DOC_FILE})
+  add_dependencies(clang-cir-doc ${output_file}DocGen)
+endfunction()
+
+add_subdirectory(IR)
+
+set(LLVM_TARGET_DEFINITIONS Passes.td)
+mlir_tablegen(Passes.h.inc -gen-pass-decls -name CIR)
+mlir_tablegen(Passes.capi.h.inc -gen-pass-capi-header --prefix CIR)
+mlir_tablegen(Passes.capi.cpp.inc -gen-pass-capi-impl --prefix CIR)
+add_public_tablegen_target(MLIRCIRPassIncGen)
+
+add_clang_mlir_doc(Passes CIRPasses ./ -gen-pass-doc)