invalidateCache in addModule and removeModules

[tapaswenipathak]

Summary

Ref: https://github.com/vgvassilev/clang/commit/758e42e823.

It can have a test adding FileManagerTestHelper as a friend function and checking on a few variables. Should it be added?

Pre: https://reviews.llvm.org/D126266.

Authored-by: Vassil Vassilev <[e-mail]>
Submitted-by: Tapasweni Pathak <[e-mail]>

[v.g.vassilev]

I think this patch is not needed in the main branch as https://github.com/llvm/llvm-project/commit/f91b6f8159b101688eef87c75179209699c0d405 removes the need of calling invalidateCache altogether.

[tapaswenipathak]

https://github.com/llvm/llvm-project/commit/ca39214f4e9fddf247e880ef9562865be850fce6#diff-a59fa24a712b79c57b4d922d0d407b8f63a9a88fa79ba0d85b0063e1a2a6fda3L157

closing, now.

clang/lib/Serialization/ModuleManager.cpp

   // Read the signature eagerly now so that we can check it.  Avoid calling
   // ReadSignature unless there's something to check though.
   if (ExpectedSignature && checkSignature(ReadSignature(NewModule->Data),
-                                          ExpectedSignature, ErrorStr))
+                                          ExpectedSignature, ErrorStr)) {
+    // Try to remove the buffer.  If it can't be removed, then it was already
+    // validated by this process.
+    if (!getModuleCache().tryToDropPCM(NewModule->FileName)) {
+      const FileEntry *FE = NewModule->File;
+      FileMgr.invalidateCache(const_cast<FileEntry *>(FE));
+    }
     return OutOfDate;
-
+  }
   // We're keeping this module.  Store it everywhere.
   Module = Modules[Entry] = NewModule.get();
 

   for (ModuleIterator victim = First; victim != Last; ++victim) {
     Modules.erase(victim->File);
 
+    const FileEntry *FE = victim->File;
+    FileMgr.invalidateCache(const_cast<FileEntry *>(FE));
     if (modMap) {
       StringRef ModuleName = victim->ModuleName;
       if (Module *mod = modMap->findModule(ModuleName)) {