[llvm][CMake][TableGen] Add all TableGen files to tablegen_compile_commands.yml (#71686)

This file is a list of files and their required include dirs, used by
the TableGen LSP server
(https://mlir.llvm.org/docs/Tools/MLIRLSP/#tablegen-lsp-language-server--tblgen-lsp-server).

Initialy this only included MLIR TableGen files, so I've expanded that
by moving it into llvm so all projects that use the llvm `tablegen`
function will be added to the file.

You could already do some things in llvm TableGen files without this,
but were limited with files that don't include their dependencies using
`include`, only with command line arguments.

Once those are in the yml file, the language server sees all that and go
to definition etc. all works.

Author: DavidSpickett

llvm/cmake/modules/TableGen.cmake

@@ -4,6 +4,10 @@
 # Adds the name of the generated file to TABLEGEN_OUTPUT.
 include(LLVMDistributionSupport)
 
+# Clear out any pre-existing compile_commands file before processing. This
+# allows for generating a clean compile_commands on each configure.
+file(REMOVE ${CMAKE_BINARY_DIR}/tablegen_compile_commands.yml)
+
 function(tablegen project ofn)
   cmake_parse_arguments(ARG "" "" "DEPENDS;EXTRA_INCLUDES" ${ARGN})
 
@@ -91,6 +95,29 @@ function(tablegen project ofn)
   # but lets us having smaller and cleaner code here.
   get_directory_property(tblgen_includes INCLUDE_DIRECTORIES)
   list(APPEND tblgen_includes ${ARG_EXTRA_INCLUDES})
+
+  # Get the current set of include paths for this td file.
+  cmake_parse_arguments(ARG "" "" "DEPENDS;EXTRA_INCLUDES" ${ARGN})
+  get_directory_property(tblgen_includes INCLUDE_DIRECTORIES)
+  list(APPEND tblgen_includes ${ARG_EXTRA_INCLUDES})
+  # Filter out any empty include items.
+  list(REMOVE_ITEM tblgen_includes "")
+
+  # Build the absolute path for the current input file.
+  if (IS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
+    set(LLVM_TARGET_DEFINITIONS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
+  else()
+    set(LLVM_TARGET_DEFINITIONS_ABSOLUTE ${CMAKE_CURRENT_SOURCE_DIR}/${LLVM_TARGET_DEFINITIONS})
+  endif()
+
+  # Append this file and its includes to the compile commands file.
+  # This file is used by the TableGen LSP Language Server (tblgen-lsp-server).
+  file(APPEND ${CMAKE_BINARY_DIR}/tablegen_compile_commands.yml
+      "--- !FileInfo:\n"
+      "  filepath: \"${LLVM_TARGET_DEFINITIONS_ABSOLUTE}\"\n"
+      "  includes: \"${CMAKE_CURRENT_SOURCE_DIR};${tblgen_includes}\"\n"
+  )
+
   # Filter out empty items before prepending each entry with -I
   list(REMOVE_ITEM tblgen_includes "")
   list(TRANSFORM tblgen_includes PREPEND -I)

mlir/cmake/modules/AddMLIR.cmake

@@ -1,36 +1,10 @@
 include(GNUInstallDirs)
 include(LLVMDistributionSupport)
 
-# Clear out any pre-existing compile_commands file before processing. This
-# allows for generating a clean compile_commands on each configure.
-file(REMOVE ${CMAKE_BINARY_DIR}/tablegen_compile_commands.yml)
-
 function(mlir_tablegen ofn)
   tablegen(MLIR ${ARGV})
   set(TABLEGEN_OUTPUT ${TABLEGEN_OUTPUT} ${CMAKE_CURRENT_BINARY_DIR}/${ofn}
       PARENT_SCOPE)
-
-  # Get the current set of include paths for this td file.
-  cmake_parse_arguments(ARG "" "" "DEPENDS;EXTRA_INCLUDES" ${ARGN})
-  get_directory_property(tblgen_includes INCLUDE_DIRECTORIES)
-  list(APPEND tblgen_includes ${ARG_EXTRA_INCLUDES})
-  # Filter out any empty include items.
-  list(REMOVE_ITEM tblgen_includes "")
-
-  # Build the absolute path for the current input file.
-  if (IS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
-    set(LLVM_TARGET_DEFINITIONS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
-  else()
-    set(LLVM_TARGET_DEFINITIONS_ABSOLUTE ${CMAKE_CURRENT_SOURCE_DIR}/${LLVM_TARGET_DEFINITIONS})
-  endif()
-
-  # Append the includes used for this file to the tablegen_compile_commands
-  # file.
-  file(APPEND ${CMAKE_BINARY_DIR}/tablegen_compile_commands.yml
-      "--- !FileInfo:\n"
-      "  filepath: \"${LLVM_TARGET_DEFINITIONS_ABSOLUTE}\"\n"
-      "  includes: \"${CMAKE_CURRENT_SOURCE_DIR};${tblgen_includes}\"\n"
-  )
 endfunction()
 
 # Clear out any pre-existing compile_commands file before processing. This