[cfe-commits] r61782 - in /cfe/trunk: include/clang/Basic/SourceManager.h lib/Basic/SourceManager.cpp
Ted Kremenek
kremenek at apple.com
Mon Jan 5 17:55:27 PST 2009
Author: kremenek
Date: Mon Jan 5 19:55:26 2009
New Revision: 61782
URL: http://llvm.org/viewvc/llvm-project?rev=61782&view=rev
Log:
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.
Modified:
cfe/trunk/include/clang/Basic/SourceManager.h
cfe/trunk/lib/Basic/SourceManager.cpp
Modified: cfe/trunk/include/clang/Basic/SourceManager.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/SourceManager.h?rev=61782&r1=61781&r2=61782&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/SourceManager.h (original)
+++ cfe/trunk/include/clang/Basic/SourceManager.h Mon Jan 5 19:55:26 2009
@@ -48,16 +48,17 @@
/// ContentCache - Once instance of this struct is kept for every file
/// loaded or used. This object owns the MemoryBuffer object.
- struct ContentCache {
+ class ContentCache {
+ /// Buffer - The actual buffer containing the characters from the input
+ /// file. This is owned by the ContentCache object.
+ const llvm::MemoryBuffer* Buffer;
+
+ public:
/// Reference to the file entry. This reference does not own
/// the FileEntry object. It is possible for this to be NULL if
/// the ContentCache encapsulates an imaginary text buffer.
const FileEntry* Entry;
- /// Buffer - The actual buffer containing the characters from the input
- /// file. This is owned by the ContentCache object.
- const llvm::MemoryBuffer* Buffer;
-
/// SourceLineCache - A new[]'d array of offsets for each source line. This
/// is lazily computed. This is owned by the ContentCache object.
unsigned* SourceLineCache;
@@ -65,9 +66,28 @@
/// NumLines - The number of lines in this ContentCache. This is only valid
/// if SourceLineCache is non-null.
unsigned NumLines;
+
+ /// getBuffer - Returns the memory buffer for the associated content.
+ const llvm::MemoryBuffer* getBuffer() const;
+
+ /// 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 this size is retrieved from the file's FileEntry.
+ unsigned getSize() const;
+
+ /// getSizeBytesMapped - Returns the number of bytes actually mapped for
+ /// this ContentCache. This can be 0 if the MemBuffer was not actually
+ /// instantiated.
+ unsigned getSizeBytesMapped() const;
+
+ void setBuffer(const llvm::MemoryBuffer* B) {
+ assert(!Buffer && "MemoryBuffer already set.");
+ Buffer = B;
+ }
ContentCache(const FileEntry* e = NULL)
- : Entry(e), Buffer(NULL), SourceLineCache(NULL), NumLines(0) {}
+ : Buffer(NULL), Entry(e), SourceLineCache(NULL), NumLines(0) {}
~ContentCache();
@@ -307,7 +327,7 @@
/// getBuffer - Return the buffer for the specified FileID.
///
const llvm::MemoryBuffer *getBuffer(unsigned FileID) const {
- return getContentCache(FileID)->Buffer;
+ return getContentCache(FileID)->getBuffer();
}
/// getBufferData - Return a pointer to the start and end of the character
@@ -506,7 +526,7 @@
/// getContentCache - Create or return a cached ContentCache for the specified
/// file. This returns null on failure.
const SrcMgr::ContentCache* getContentCache(const FileEntry* SourceFile);
-
+
/// createMemBufferContentCache - Create a new ContentCache for the specified
/// memory buffer.
const SrcMgr::ContentCache*
Modified: cfe/trunk/lib/Basic/SourceManager.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/SourceManager.cpp?rev=61782&r1=61781&r2=61782&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/SourceManager.cpp (original)
+++ cfe/trunk/lib/Basic/SourceManager.cpp Mon Jan 5 19:55:26 2009
@@ -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, "
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