r269769 - [PCH] Fixed bug with preamble invalidation when overridden files change

[Cameron Desrochers via cfe-commits]

Author: cameron314
Date: Tue May 17 09:34:53 2016
New Revision: 269769

URL: http://llvm.org/viewvc/llvm-project?rev=269769&view=rev
Log:
[PCH] Fixed bug with preamble invalidation when overridden files change

When remapped files were changed, they would not always cause the preamble's PCH to be invalidated, because the remapped path didn't necessarily match the include path (e.g. slash direction -- this happens a lot on Windows). I fixed this by moving to a llvm::sys::fs::UniqueID-based map instead of comparing paths stringwise.

Differential Revision: http://reviews.llvm.org/D20137

Modified:
    cfe/trunk/lib/Frontend/ASTUnit.cpp

Modified: cfe/trunk/lib/Frontend/ASTUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/ASTUnit.cpp?rev=269769&r1=269768&r2=269769&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/ASTUnit.cpp (original)
+++ cfe/trunk/lib/Frontend/ASTUnit.cpp Tue May 17 09:34:53 2016
@@ -1378,7 +1378,7 @@ ASTUnit::getMainBufferWithPrecompiledPre
           
       // First, make a record of those files that have been overridden via
       // remapping or unsaved_files.
-      llvm::StringMap<PreambleFileHash> OverriddenFiles;
+      std::map<llvm::sys::fs::UniqueID, PreambleFileHash> OverriddenFiles;
       for (const auto &R : PreprocessorOpts.RemappedFiles) {
         if (AnyFileChanged)
           break;
@@ -1391,24 +1391,38 @@ ASTUnit::getMainBufferWithPrecompiledPre
           break;
         }
 
-        OverriddenFiles[R.first] = PreambleFileHash::createForFile(
+        OverriddenFiles[Status.getUniqueID()] = PreambleFileHash::createForFile(
             Status.getSize(), Status.getLastModificationTime().toEpochTime());
       }
 
       for (const auto &RB : PreprocessorOpts.RemappedFileBuffers) {
         if (AnyFileChanged)
           break;
-        OverriddenFiles[RB.first] =
+
+        vfs::Status Status;
+        if (FileMgr->getNoncachedStatValue(RB.first, Status)) {
+          AnyFileChanged = true;
+          break;
+        }
+
+        OverriddenFiles[Status.getUniqueID()] =
             PreambleFileHash::createForMemoryBuffer(RB.second);
       }
        
       // Check whether anything has changed.
-      for (llvm::StringMap<PreambleFileHash>::iterator 
+      for (llvm::StringMap<PreambleFileHash>::iterator
              F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
            !AnyFileChanged && F != FEnd; 
            ++F) {
-        llvm::StringMap<PreambleFileHash>::iterator Overridden
-          = OverriddenFiles.find(F->first());
+        vfs::Status Status;
+        if (FileMgr->getNoncachedStatValue(F->first(), Status)) {
+          // If we can't stat the file, assume that something horrible happened.
+          AnyFileChanged = true;
+          break;
+        }
+
+        std::map<llvm::sys::fs::UniqueID, PreambleFileHash>::iterator Overridden
+          = OverriddenFiles.find(Status.getUniqueID());
         if (Overridden != OverriddenFiles.end()) {
           // This file was remapped; check whether the newly-mapped file 
           // matches up with the previous mapping.
@@ -1418,13 +1432,9 @@ ASTUnit::getMainBufferWithPrecompiledPre
         }
         
         // The file was not remapped; check whether it has changed on disk.
-        vfs::Status Status;
-        if (FileMgr->getNoncachedStatValue(F->first(), Status)) {
-          // If we can't stat the file, assume that something horrible happened.
-          AnyFileChanged = true;
-        } else if (Status.getSize() != uint64_t(F->second.Size) ||
-                   Status.getLastModificationTime().toEpochTime() !=
-                       uint64_t(F->second.ModTime))
+        if (Status.getSize() != uint64_t(F->second.Size) ||
+            Status.getLastModificationTime().toEpochTime() !=
+                uint64_t(F->second.ModTime))
           AnyFileChanged = true;
       }