1 files changed, 90 insertions, 0 deletions
diff --git a/subprojects/lix-clang-tidy/FixIncludes.cc b/subprojects/lix-clang-tidy/FixIncludes.cc
new file mode 100644
index 000000000..602d3d355
--- /dev/null
+++ b/subprojects/lix-clang-tidy/FixIncludes.cc
@@ -0,0 +1,90 @@
+#include "FixIncludes.hh"
+#include <clang-tidy/ClangTidyCheck.h>
+#include <clang/Basic/Diagnostic.h>
+#include <clang/Basic/SourceManager.h>
+#include <clang/Lex/PPCallbacks.h>
+#include <clang/Lex/Preprocessor.h>
+#include <llvm/ADT/StringRef.h>
+#include <llvm/Support/Debug.h>
+#include <memory>
+#include <set>
+#include <string>
+
+namespace nix::clang_tidy {
+
+using namespace clang;
+using namespace clang::tidy;
+
+class FixIncludesCallbacks : public PPCallbacks {
+public:
+  ClangTidyCheck &Check;
+  Preprocessor &PP;
+  FixIncludesCallbacks(ClangTidyCheck &Check, Preprocessor &PP)
+      : Check(Check), PP(PP) {}
+
+private:
+  bool Ignore = false;
+  virtual void LexedFileChanged(FileID FID, LexedFileChangeReason Reason,
+                                SrcMgr::CharacteristicKind FileType,
+                                FileID PrevFID, SourceLocation Loc) override;
+
+  virtual void InclusionDirective(SourceLocation HashLoc,
+                                  const Token &IncludeTok, StringRef FileName,
+                                  bool IsAngled, CharSourceRange FilenameRange,
+                                  OptionalFileEntryRef File,
+                                  StringRef SearchPath, StringRef RelativePath,
+                                  const Module *Imported,
+                                  SrcMgr::CharacteristicKind FileType) override;
+};
+
+void FixIncludesCallbacks::LexedFileChanged(FileID, LexedFileChangeReason,
+                                            SrcMgr::CharacteristicKind FileType,
+                                            FileID, SourceLocation) {
+  Ignore = FileType != SrcMgr::C_User;
+}
+
+void FixIncludesCallbacks::InclusionDirective(
+    SourceLocation, const Token &, StringRef FileName, bool IsAngled,
+    CharSourceRange FilenameRange, OptionalFileEntryRef File, StringRef,
+    StringRef, const Module *, SrcMgr::CharacteristicKind) {
+  if (Ignore)
+    return;
+
+  // FIXME: this is kinda evil, but this is a one-time fixup
+  const std::vector<std::string> SourceDirs = {"src/", "include/lix/"};
+
+  const auto Bracketize = [IsAngled](StringRef s) {
+    return IsAngled ? ("<" + s + ">").str() : ("\"" + s + "\"").str();
+  };
+
+  for (const auto &SourceDir : SourceDirs) {
+    const bool IsAlreadyFixed = FileName.starts_with("lix/lib");
+    if (File && File->getNameAsRequested().contains(SourceDir) &&
+        !IsAlreadyFixed) {
+      StringRef Name = File->getNameAsRequested();
+      auto Idx = Name.find(SourceDir);
+      assert(Idx != std::string::npos);
+      std::string Suffix = Name.drop_front(Idx + SourceDir.length()).str();
+
+      if (!Suffix.starts_with("lib")) {
+        llvm::dbgs() << "ignored: " << Suffix << "\n";
+        return;
+      }
+
+      Suffix = "lix/" + Suffix;
+
+      auto Diag = Check.diag(FilenameRange.getBegin(),
+                             "include needs to specify the source subdir");
+
+      Diag << FilenameRange
+           << FixItHint::CreateReplacement(FilenameRange, Bracketize(Suffix));
+    }
+  }
+}
+
+void FixIncludesCheck::registerPPCallbacks(const SourceManager &,
+                                           Preprocessor *PP, Preprocessor *) {
+  PP->addPPCallbacks(std::make_unique<FixIncludesCallbacks>(*this, *PP));
+}
+
+}; // namespace nix::clang_tidy