Misc changes to SourceManager::ContentCache:
- 'Buffer' is now private and must be accessed via 'getBuffer()'.
This paves the way for lazily mapping in source files on demand.
- Added 'getSize()' (which gets the size of the content without
necessarily accessing the MemBuffer) and 'getSizeBytesMapped()'.
- Modifed SourceManager to use these new methods. This reduces the
number of places that actually access the MemBuffer object for a file
to those that actually look at the character data.
These changes result in no performance change for -fsyntax-only on Cocoa.h.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61782 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 44a6d66..b040459 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -29,6 +29,26 @@
delete [] SourceLineCache;
}
+/// getSizeBytesMapped - Returns the number of bytes actually mapped for
+/// this ContentCache. This can be 0 if the MemBuffer was not actually
+/// instantiated.
+unsigned ContentCache::getSizeBytesMapped() const {
+ return Buffer ? Buffer->getBufferSize() : 0;
+}
+
+/// getSize - Returns the size of the content encapsulated by this ContentCache.
+/// This can be the size of the source file or the size of an arbitrary
+/// scratch buffer. If the ContentCache encapsulates a source file, that
+/// file is not lazily brought in from disk to satisfy this query.
+unsigned ContentCache::getSize() const {
+ return Entry ? Entry->getSize() : Buffer->getBufferSize();
+}
+
+const llvm::MemoryBuffer* ContentCache::getBuffer() const {
+ return Buffer;
+}
+
+
/// getFileInfo - Create or return a cached FileInfo for the specified file.
///
const ContentCache* SourceManager::getContentCache(const FileEntry *FileEnt) {
@@ -49,7 +69,9 @@
ContentCache& Entry = const_cast<ContentCache&>(*FileInfos.insert(I,FileEnt));
- Entry.Buffer = File;
+ // FIXME: Shortly the above logic that creates a MemBuffer will be moved
+ // to ContentCache::getBuffer(). This way it can be done lazily.
+ Entry.setBuffer(File);
Entry.SourceLineCache = 0;
Entry.NumLines = 0;
return &Entry;
@@ -66,7 +88,7 @@
// temporary we would use in the call to "push_back".
MemBufferInfos.push_back(ContentCache());
ContentCache& Entry = const_cast<ContentCache&>(MemBufferInfos.back());
- Entry.Buffer = Buffer;
+ Entry.setBuffer(Buffer);
return &Entry;
}
@@ -81,7 +103,7 @@
// to fit an arbitrary position in the file in the FilePos field. To handle
// this, we create one FileID for each chunk of the file that fits in a
// FilePos field.
- unsigned FileSize = File->Buffer->getBufferSize();
+ unsigned FileSize = File->getSize();
if (FileSize+1 < (1 << SourceLocation::FilePosBits)) {
FileIDs.push_back(FileIDInfo::get(IncludePos, 0, File, FileCharacter));
assert(FileIDs.size() < (1 << SourceLocation::FileIDBits) &&
@@ -159,7 +181,8 @@
// heavily used by -E mode.
SL = getPhysicalLoc(SL);
- return getContentCache(SL.getFileID())->Buffer->getBufferStart() +
+ // Note that calling 'getBuffer()' may lazily page in a source file.
+ return getContentCache(SL.getFileID())->getBuffer()->getBufferStart() +
getFullFilePos(SL);
}
@@ -187,12 +210,17 @@
const char *SourceManager::getSourceName(SourceLocation Loc) const {
unsigned FileID = Loc.getFileID();
if (FileID == 0) return "";
- return getContentCache(FileID)->Buffer->getBufferIdentifier();
+
+ // To get the source name, first consult the FileEntry (if one exists) before
+ // the MemBuffer as this will avoid unnecessarily paging in the MemBuffer.
+ const SrcMgr::ContentCache* C = getContentCache(FileID);
+ return C->Entry ? C->Entry->getName() : C->getBuffer()->getBufferIdentifier();
}
static void ComputeLineNumbers(ContentCache* FI) DISABLE_INLINE;
-static void ComputeLineNumbers(ContentCache* FI) {
- const MemoryBuffer *Buffer = FI->Buffer;
+static void ComputeLineNumbers(ContentCache* FI) {
+ // Note that calling 'getBuffer()' may lazily page in the file.
+ const MemoryBuffer *Buffer = FI->getBuffer();
// Find the file offsets of all of the *physical* source lines. This does
// not look at trigraphs, escaped newlines, or anything else tricky.
@@ -341,7 +369,7 @@
for (std::set<ContentCache>::const_iterator I =
FileInfos.begin(), E = FileInfos.end(); I != E; ++I) {
NumLineNumsComputed += I->SourceLineCache != 0;
- NumFileBytesMapped += I->Buffer->getBufferSize();
+ NumFileBytesMapped += I->getSizeBytesMapped();
}
llvm::cerr << NumFileBytesMapped << " bytes of files mapped, "