<rdar://problem/13426257> Introduce SDKSettings.plist as an input file dependency for PCH/modules.
When we're building a precompiled header or module against an SDK on
Darwin, there will be a file SDKSettings.plist in the sysroot. Since
stat()'ing every system header on which a module or PCH file depends
is performance suicide, we instead stat() just SDKSettings.plist. This
hack works well on Darwin; it's unclear how we want to handle this on
other platforms. If there is a canonical file, we should use it; if
not, we either have to take the performance hit of stat()'ing system
headers repeatedly or roll the dice by not checking anything.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177194 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 10a8044..b113c76 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1213,11 +1213,24 @@
Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
}
- WriteInputFiles(Context.SourceMgr, isysroot);
+ WriteInputFiles(Context.SourceMgr,
+ PP.getHeaderSearchInfo().getHeaderSearchOpts(),
+ isysroot);
Stream.ExitBlock();
}
-void ASTWriter::WriteInputFiles(SourceManager &SourceMgr, StringRef isysroot) {
+namespace {
+ /// \brief An input file.
+ struct InputFileEntry {
+ const FileEntry *File;
+ bool IsSystemFile;
+ bool BufferOverridden;
+ };
+}
+
+void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
+ HeaderSearchOptions &HSOpts,
+ StringRef isysroot) {
using namespace llvm;
Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
RecordData Record;
@@ -1234,7 +1247,7 @@
// Get all ContentCache objects for files, sorted by whether the file is a
// system one or not. System files go at the back, users files at the front.
- std::deque<const SrcMgr::ContentCache *> SortedFiles;
+ std::deque<InputFileEntry> SortedFiles;
for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
// Get this source location entry.
const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
@@ -1247,20 +1260,38 @@
if (!Cache->OrigEntry)
continue;
+ InputFileEntry Entry;
+ Entry.File = Cache->OrigEntry;
+ Entry.IsSystemFile = Cache->IsSystemFile;
+ Entry.BufferOverridden = Cache->BufferOverridden;
if (Cache->IsSystemFile)
- SortedFiles.push_back(Cache);
+ SortedFiles.push_back(Entry);
else
- SortedFiles.push_front(Cache);
+ SortedFiles.push_front(Entry);
+ }
+
+ // If we have an isysroot for a Darwin SDK, include its SDKSettings.plist in
+ // the set of (non-system) input files. This is simple heuristic for
+ // detecting whether the system headers may have changed, because it is too
+ // expensive to stat() all of the system headers.
+ FileManager &FileMgr = SourceMgr.getFileManager();
+ if (!HSOpts.Sysroot.empty()) {
+ llvm::SmallString<128> SDKSettingsFileName(HSOpts.Sysroot);
+ llvm::sys::path::append(SDKSettingsFileName, "SDKSettings.plist");
+ if (const FileEntry *SDKSettingsFile = FileMgr.getFile(SDKSettingsFileName)) {
+ InputFileEntry Entry = { SDKSettingsFile, false, false };
+ SortedFiles.push_front(Entry);
+ }
}
unsigned UserFilesNum = 0;
// Write out all of the input files.
std::vector<uint32_t> InputFileOffsets;
- for (std::deque<const SrcMgr::ContentCache *>::iterator
+ for (std::deque<InputFileEntry>::iterator
I = SortedFiles.begin(), E = SortedFiles.end(); I != E; ++I) {
- const SrcMgr::ContentCache *Cache = *I;
+ const InputFileEntry &Entry = *I;
- uint32_t &InputFileID = InputFileIDs[Cache->OrigEntry];
+ uint32_t &InputFileID = InputFileIDs[Entry.File];
if (InputFileID != 0)
continue; // already recorded this file.
@@ -1269,7 +1300,7 @@
InputFileID = InputFileOffsets.size();
- if (!Cache->IsSystemFile)
+ if (!Entry.IsSystemFile)
++UserFilesNum;
Record.clear();
@@ -1277,19 +1308,19 @@
Record.push_back(InputFileOffsets.size());
// Emit size/modification time for this file.
- Record.push_back(Cache->OrigEntry->getSize());
- Record.push_back(Cache->OrigEntry->getModificationTime());
+ Record.push_back(Entry.File->getSize());
+ Record.push_back(Entry.File->getModificationTime());
// Whether this file was overridden.
- Record.push_back(Cache->BufferOverridden);
+ Record.push_back(Entry.BufferOverridden);
// Turn the file name into an absolute path, if it isn't already.
- const char *Filename = Cache->OrigEntry->getName();
+ const char *Filename = Entry.File->getName();
SmallString<128> FilePath(Filename);
// Ask the file manager to fixup the relative path for us. This will
// honor the working directory.
- SourceMgr.getFileManager().FixupRelativePath(FilePath);
+ FileMgr.FixupRelativePath(FilePath);
// FIXME: This call to make_absolute shouldn't be necessary, the
// call to FixupRelativePath should always return an absolute path.
@@ -1300,7 +1331,7 @@
Stream.EmitRecordWithBlob(IFAbbrevCode, Record, Filename);
}
-
+
Stream.ExitBlock();
// Create input file offsets abbreviation.