[PCH] When validating that the files coming from PCH did not change, also
validate that we didn't override the contents of any of such files.
If this is detected, emit a diagnostic error and recover gracefully
by using the contents of the original file that the PCH was built from.
Part of rdar://11305263
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156107 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index f224056..f1ea091 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -2473,6 +2473,26 @@
Error("source location entry is incorrect");
return Failure;
}
+
+ off_t StoredSize = (off_t)Record[4];
+ time_t StoredTime = (time_t)Record[5];
+
+ // Check if there was a request to override the contents of the file
+ // that was part of the precompiled header. Overridding such a file
+ // can lead to problems when lexing using the source locations from the
+ // PCH.
+ SourceManager &SM = getSourceManager();
+ if (SM.isFileOverridden(File)) {
+ Error(diag::err_fe_pch_file_overridden, Filename);
+ // After emitting the diagnostic, recover by disabling the override so
+ // that the original file will be used.
+ SM.disableFileContentsOverride(File);
+ // The FileEntry is a virtual file entry with the size of the contents
+ // that would override the original contents. Set it to the original's
+ // size/time.
+ FileMgr.modifyFileEntry(const_cast<FileEntry*>(File),
+ StoredSize, StoredTime);
+ }
// The stat info from the FileEntry came from the cached stat
// info of the PCH, so we cannot trust it.
@@ -2482,12 +2502,12 @@
StatBuf.st_mtime = File->getModificationTime();
}
- if (((off_t)Record[4] != StatBuf.st_size
+ if ((StoredSize != StatBuf.st_size
#if !defined(LLVM_ON_WIN32)
// In our regression testing, the Windows file system seems to
// have inconsistent modification times that sometimes
// erroneously trigger this error-handling path.
- || (time_t)Record[5] != StatBuf.st_mtime
+ || StoredTime != StatBuf.st_mtime
#endif
)) {
Error(diag::err_fe_pch_file_modified, Filename);