Introduce a simple "hint" scheme to eliminate the quadratic behavior
associated with deserializing macro history for an identifier.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165729 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 2c0814c..7888a26 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -519,7 +519,8 @@
/// \brief Specify a macro for this identifier.
void setMacroInfo(IdentifierInfo *II, MacroInfo *MI);
/// \brief Add a MacroInfo that was loaded from an AST file.
- void addLoadedMacroInfo(IdentifierInfo *II, MacroInfo *MI);
+ void addLoadedMacroInfo(IdentifierInfo *II, MacroInfo *MI,
+ MacroInfo *Hint = 0);
/// \brief Make the given MacroInfo, that was loaded from an AST file and
/// previously hidden, visible.
void makeLoadedMacroInfoVisible(IdentifierInfo *II, MacroInfo *MI);
diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 2a9afc9..4e8531a 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -1433,7 +1433,7 @@
unsigned LocalID);
/// \brief Retrieve the macro with the given ID.
- MacroInfo *getMacro(serialization::MacroID ID);
+ MacroInfo *getMacro(serialization::MacroID ID, MacroInfo *Hint = 0);
/// \brief Retrieve the global macro ID corresponding to the given local
/// ID within the given module file.
@@ -1582,7 +1582,7 @@
Expr *ReadSubExpr();
/// \brief Reads the macro record located at the given offset.
- void ReadMacroRecord(ModuleFile &F, uint64_t Offset);
+ void ReadMacroRecord(ModuleFile &F, uint64_t Offset, MacroInfo *Hint = 0);
/// \brief Determine the global preprocessed entity ID that corresponds to
/// the given local ID within the given module.
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 8db74f2..c717816 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -55,7 +55,8 @@
II->setChangedSinceDeserialization();
}
-void Preprocessor::addLoadedMacroInfo(IdentifierInfo *II, MacroInfo *MI) {
+void Preprocessor::addLoadedMacroInfo(IdentifierInfo *II, MacroInfo *MI,
+ MacroInfo *Hint) {
assert(MI && "Missing macro?");
assert(MI->isFromAST() && "Macro is not from an AST?");
assert(!MI->getPreviousDefinition() && "Macro already in chain?");
@@ -105,8 +106,7 @@
}
// The macro is not a definition; put it at the end of the list.
- // FIXME: Adding macro history is quadratic, but a hint could fix this.
- MacroInfo *Prev = StoredMI;
+ MacroInfo *Prev = Hint? Hint : StoredMI;
while (Prev->getPreviousDefinition())
Prev = Prev->getPreviousDefinition();
Prev->setPreviousDefinition(MI);
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 736f082..5657ee2 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -1241,7 +1241,8 @@
}
}
-void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset) {
+void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset,
+ MacroInfo *Hint) {
llvm::BitstreamCursor &Stream = F.MacroCursor;
// Keep track of where we are in the stream, then jump back there
@@ -1370,7 +1371,7 @@
MI->setHidden(Hidden);
// Finally, install the macro.
- PP.addLoadedMacroInfo(II, MI);
+ PP.addLoadedMacroInfo(II, MI, Hint);
// Remember that we saw this macro last so that we add the tokens that
// form its body to it.
@@ -5795,7 +5796,7 @@
return LocalID + I->second;
}
-MacroInfo *ASTReader::getMacro(MacroID ID) {
+MacroInfo *ASTReader::getMacro(MacroID ID, MacroInfo *Hint) {
if (ID == 0)
return 0;
@@ -5811,7 +5812,7 @@
assert(I != GlobalMacroMap.end() && "Corrupted global macro map");
ModuleFile *M = I->second;
unsigned Index = ID - M->BaseMacroID;
- ReadMacroRecord(*M, M->MacroOffsets[Index]);
+ ReadMacroRecord(*M, M->MacroOffsets[Index], Hint);
}
return MacrosLoaded[ID];
@@ -6512,9 +6513,10 @@
for (unsigned I = 0; I != PendingMacroIDs.size(); ++I) {
// FIXME: std::move here
SmallVector<MacroID, 2> GlobalIDs = PendingMacroIDs.begin()[I].second;
+ MacroInfo *Hint = 0;
for (unsigned IDIdx = 0, NumIDs = GlobalIDs.size(); IDIdx != NumIDs;
++IDIdx) {
- getMacro(GlobalIDs[IDIdx]);
+ Hint = getMacro(GlobalIDs[IDIdx], Hint);
}
}
PendingMacroIDs.clear();