1 files changed, 98 insertions, 0 deletions
diff --git a/meson/clang-tidy/meson.build b/meson/clang-tidy/meson.build
new file mode 100644
index 000000000..9aba5fbdc
--- /dev/null
+++ b/meson/clang-tidy/meson.build
@@ -0,0 +1,98 @@
+# The clang-tidy target for Lix
+
+run_clang_tidy = find_program('run-clang-tidy', required : false)
+# Although this looks like it wants to be pkg-config, pkg-config does not
+# really work for *plugins*, which are executable-like .so files that also
+# cannot be found via find_program. Fun!
+if get_option('lix-clang-tidy-checks-path') != ''
+  lix_clang_tidy_so = get_option('lix-clang-tidy-checks-path')
+  lix_clang_tidy_so_found = true
+else
+  lix_clang_tidy_subproj = subproject(
+    'lix-clang-tidy',
+    required : false,
+    default_options : {'build-by-default': false}
+  )
+  if lix_clang_tidy_subproj.found()
+    lix_clang_tidy_so = lix_clang_tidy_subproj.get_variable('lix_clang_tidy')
+    lix_clang_tidy_so_found = true
+  else
+    lix_clang_tidy_so_found = false
+  endif
+endif
+
+# Due to numerous problems, such as:
+# - Meson does not expose pch targets, but *fine*, I can just ask Ninja for
+#   them with `ninja -t targets rule cpp_PCH` and build them manually:
+#   https://github.com/mesonbuild/meson/issues/13499
+# - Nixpkgs stdenv buries the cc-wrapper under a giant pile of assumptions
+#   about the cc-wrapper actually being used on the cc of a stdenv, rather than
+#   independently for clang-tidy, and we need to use cc-wrapper to get the
+#   correct hardening flags so that clang-tidy can actually parse the PCH file
+#
+# I give up. I am going to delete the damn PCH args and then it will work.
+meson.add_postconf_script(
+  python,
+  meson.current_source_dir() / 'clean_compdb.py',
+  meson.global_build_root() / 'compile_commands.json',
+  meson.current_build_dir() / 'compile_commands.json',
+)
+
+# Horrible hack to get around not being able to depend on another target's
+# generated headers in any way in the meson DSL
+# https://github.com/mesonbuild/meson/issues/12817 which was incorrectly
+# closed, if you *actually* need to generate the files once.
+# Also related: https://github.com/mesonbuild/meson/issues/3667
+#
+# Or we could ban meson generators because their design is broken.
+build_all_generated_headers = custom_target(
+  command : [
+    python,
+    meson.current_source_dir() / 'build_required_targets.py',
+    meson.global_build_root(),
+  ],
+  output : 'generated_headers.stamp',
+  build_by_default : false,
+  build_always_stale : true,
+)
+
+if lix_clang_tidy_so_found
+  run_clang_tidy_args = [
+    '-load',
+    lix_clang_tidy_so,
+    '-p',
+    # We have to workaround a run-clang-tidy bug too, so we must give the
+    # directory name rather than the actual compdb file.
+    # https://github.com/llvm/llvm-project/issues/101440
+    meson.current_build_dir(),
+    '-quiet',
+  ]
+  run_target(
+    'clang-tidy',
+    command : [
+      # XXX: This explicitly invokes it with python because of a nixpkgs bug
+      # where clang-unwrapped does not patch interpreters in run-clang-tidy.
+      # However, making clang-unwrapped depend on python is also silly, so idk.
+      python,
+      run_clang_tidy,
+      run_clang_tidy_args,
+      '-warnings-as-errors',
+      '*',
+    ],
+    depends : [
+      build_all_generated_headers,
+    ],
+  )
+  run_target(
+    'clang-tidy-fix',
+    command : [
+      python,
+      run_clang_tidy,
+      run_clang_tidy_args,
+      '-fix',
+    ],
+    depends : [
+      build_all_generated_headers,
+    ],
+  )
+endif