[PATCH] D75951: draft

[Vy Nguyen via Phabricator via cfe-commits]

oontvoo created this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
oontvoo retitled this revision from "Make a distinction between import and pragma-once, and keep tracked of already-included pragma-once files." to "draft ".
oontvoo edited the summary of this revision.
oontvoo added a reviewer: jyknight.

Make a distinction between import and pragma-once, and keep tracked of already-included pragma-once files.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D75951

Files:
  clang/include/clang/Lex/HeaderSearch.h
  clang/lib/Lex/HeaderSearch.cpp


Index: clang/lib/Lex/HeaderSearch.cpp
===================================================================
--- clang/lib/Lex/HeaderSearch.cpp
+++ clang/lib/Lex/HeaderSearch.cpp
@@ -1253,8 +1253,6 @@
   // Get information about this file.
   HeaderFileInfo &FileInfo = getFileInfo(File);
 
-  // FIXME: this is a workaround for the lack of proper modules-aware support
-  // for #import / #pragma once
   auto TryEnterImported = [&]() -> bool {
     if (!ModulesEnabled)
       return false;
@@ -1300,13 +1298,24 @@
     FileInfo.isImport = true;
 
     // Has this already been #import'ed or #include'd?
+    bool try_enter = TryEnterImported();
     if (FileInfo.NumIncludes && !TryEnterImported())
       return false;
   } else {
-    // Otherwise, if this is a #include of a file that was previously #import'd
-    // or if this is the second #include of a #pragma once file, ignore it.
-    if (FileInfo.isImport && !TryEnterImported())
+    // If the file has #pragma once guard and if it's been included
+    // then skip it.
+    if (FileInfo.isPragmaOnce) {
+      auto &it = included_pragma_files.find(FileEntry);
+      if (it != included_pragma_files.end() && it->second) {
+        return false;
+      } else {
+        it->second = true;
+      }
+    } else if (FileInfo.isImport && !TryEnterImported) {
+      // Otherwise, if this is a #include of a file that was previously
+      // #import'd ignore it.
       return false;
+    }
   }
 
   // Next, check to see if the file is wrapped with #ifndef guards.  If so, and
Index: clang/include/clang/Lex/HeaderSearch.h
===================================================================
--- clang/include/clang/Lex/HeaderSearch.h
+++ clang/include/clang/Lex/HeaderSearch.h
@@ -250,6 +250,9 @@
   /// Entity used to look up stored header file information.
   ExternalHeaderFileInfoSource *ExternalSource = nullptr;
 
+  // Set of #pragma_once file already seen.
+  llvm::DenseMap<const FileEntry *, bool> included_pragma_files;
+
 public:
   HeaderSearch(std::shared_ptr<HeaderSearchOptions> HSOpts,
                SourceManager &SourceMgr, DiagnosticsEngine &Diags,


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