improve comments, implement a trivial single-entry cache in
SourceManager::getInstantiationLoc. With this change, every token
expanded from a macro doesn't get its own MacroID. :)
This reduces # macro IDs in carbon.h from 16805 to 9197
llvm-svn: 40108
diff --git a/clang/Basic/SourceManager.cpp b/clang/Basic/SourceManager.cpp
index 3e2623c..0994163 100644
--- a/clang/Basic/SourceManager.cpp
+++ b/clang/Basic/SourceManager.cpp
@@ -165,16 +165,35 @@
/// getInstantiationLoc - Return a new SourceLocation that encodes the fact
/// that a token from physloc PhysLoc should actually be referenced from
/// InstantiationLoc.
-SourceLocation SourceManager::getInstantiationLoc(SourceLocation VirtLoc,
+SourceLocation SourceManager::getInstantiationLoc(SourceLocation PhysLoc,
SourceLocation InstantLoc) {
// The specified source location may be a mapped location, due to a macro
// instantiation or #line directive. Strip off this information to find out
// where the characters are actually located.
- SourceLocation PhysLoc = getPhysicalLoc(VirtLoc);
+ PhysLoc = getPhysicalLoc(PhysLoc);
// Resolve InstantLoc down to a real logical location.
InstantLoc = getLogicalLoc(InstantLoc);
+
+ // If the last macro id is close to the currently requested location, try to
+ // reuse it. This implements a single-entry cache.
+ if (!MacroIDs.empty()) {
+ MacroIDInfo &LastOne = MacroIDs.back();
+ if (LastOne.getInstantiationLoc() == InstantLoc &&
+ LastOne.getPhysicalLoc().getFileID() == PhysLoc.getFileID()) {
+
+ int PhysDelta = PhysLoc.getRawFilePos() -
+ LastOne.getPhysicalLoc().getRawFilePos();
+ if (unsigned(PhysDelta) < (1 << SourceLocation::MacroPhysOffsBits))
+ return SourceLocation::getMacroLoc(MacroIDs.size()-1,
+ (unsigned)PhysDelta, 0);
+
+ }
+ }
+
+
+
// FIXME: intelligently cache macroid's.
MacroIDs.push_back(MacroIDInfo::get(InstantLoc, PhysLoc));
diff --git a/clang/include/clang/Basic/SourceLocation.h b/clang/include/clang/Basic/SourceLocation.h
index d107b0b..f0dd026 100644
--- a/clang/include/clang/Basic/SourceLocation.h
+++ b/clang/include/clang/Basic/SourceLocation.h
@@ -28,8 +28,8 @@
FileIDBits = 14,
FilePosBits = 32-1-FileIDBits,
- MacroIDBits = 23,
- MacroPhysOffsBits = 5,
+ MacroIDBits = 19,
+ MacroPhysOffsBits = 9,
MacroLogOffBits = 3
};
@@ -106,7 +106,7 @@
unsigned getMacroLogOffs() const {
assert(isMacroID() && "Is not a macro id!");
- return ID & ((1 << MacroPhysOffsBits)-1);
+ return ID & ((1 << MacroLogOffBits)-1);
}
/// getFileLocWithOffset - Return a source location with the specified offset
diff --git a/clang/include/clang/Basic/SourceManager.h b/clang/include/clang/Basic/SourceManager.h
index 042dda9..414b178 100644
--- a/clang/include/clang/Basic/SourceManager.h
+++ b/clang/include/clang/Basic/SourceManager.h
@@ -53,8 +53,8 @@
typedef std::pair<const FileEntry * const, FileInfo> InfoRec;
/// FileIDInfo - Information about a FileID, basically just the logical file
- /// that it represents and include stack information. A SourceLocation is a
- /// byte offset from the start of this.
+ /// that it represents and include stack information. A File SourceLocation
+ /// is a byte offset from the start of this.
///
/// FileID's are used to compute the location of a character in memory as well
/// as the logical source location, which can be differ from the physical
@@ -63,16 +63,12 @@
///
/// Each FileID has include stack information, indicating where it came from.
/// For the primary translation unit, it comes from SourceLocation() aka 0.
+ /// This information encodes the #include chain that a token was instantiated
+ /// from.
///
- /// There are three types of FileID's:
- /// 1. Normal MemoryBuffer (file). These are represented by a "InfoRec *",
- /// describing the source file, and a Chunk number, which factors into
- /// the SourceLocation's offset from the start of the buffer.
- /// 2. Macro Expansions. These indicate that the logical location is
- /// totally different than the physical location. The logical source
- /// location is specified by the IncludeLoc. The physical location is
- /// the FilePos of the token's SourceLocation combined with the FileID
- /// from MacroTokenFileID.
+ /// FileIDInfos contain a "InfoRec *", describing the source file, and a Chunk
+ /// number, which allows a SourceLocation to index into very large files
+ /// (those which there are not enough FilePosBits to address).
///
struct FileIDInfo {
private:
@@ -104,6 +100,11 @@
const InfoRec *getInfo() const { return Info; }
};
+ /// MacroIDInfo - Macro SourceLocations refer to these records by their ID.
+ /// Each MacroIDInfo encodes the Instantiation location - where the macro was
+ /// instantiated, and the PhysicalLoc - where the actual character data for
+ /// the token came from. An actual macro SourceLocation stores deltas from
+ /// these positions.
class MacroIDInfo {
SourceLocation InstantiationLoc, PhysicalLoc;
public:
@@ -153,13 +154,8 @@
/// MacroIDs - Information about each MacroID.
std::vector<SrcMgr::MacroIDInfo> MacroIDs;
- /// LastInstantiationLoc_* - Cache the last instantiation request for fast
- /// lookup. Macros often want many tokens instantated at the same location.
- SourceLocation LastInstantiationLoc_InstantLoc;
- unsigned LastInstantiationLoc_MacroFID;
- unsigned LastInstantiationLoc_Result;
public:
- SourceManager() { LastInstantiationLoc_MacroFID = ~0U; }
+ SourceManager() {}
~SourceManager();
/// createFileID - Create a new FileID that represents the specified file
@@ -249,8 +245,8 @@
// File locations are both physical and logical.
if (Loc.isFileID()) return Loc;
- SourceLocation ILoc = MacroIDs[Loc.getMacroID()].getPhysicalLoc();
- return ILoc.getFileLocWithOffset(Loc.getMacroPhysOffs());
+ SourceLocation PLoc = MacroIDs[Loc.getMacroID()].getPhysicalLoc();
+ return PLoc.getFileLocWithOffset(Loc.getMacroPhysOffs());
}
/// getFileEntryForLoc - Return the FileEntry record for the physloc of the