Simplify lifetime management of MacroInfo objects in Preprocessor by having the Preprocessor maintain them in a linked
list of allocated MacroInfos. This requires only 1 extra pointer per MacroInfo object, and allows us to blow them
away in one place. This fixes an elusive memory leak with MacroInfos (whose exact location I couldn't still figure
out despite substantial digging).
Fixes <rdar://problem/8361834>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116842 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 752cbed..a1a68dc 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -14,6 +14,7 @@
#ifndef LLVM_CLANG_LEX_PREPROCESSOR_H
#define LLVM_CLANG_LEX_PREPROCESSOR_H
+#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Lexer.h"
#include "clang/Lex/PTHLexer.h"
#include "clang/Lex/PPCallbacks.h"
@@ -251,6 +252,15 @@
/// invoked (at which point the last position is popped).
std::vector<CachedTokensTy::size_type> BacktrackPositions;
+ struct MacroInfoChain {
+ MacroInfo MI;
+ MacroInfoChain *Next;
+ };
+
+ /// MacroInfos are managed as a chain for easy disposal. This is the head
+ /// of that list.
+ MacroInfoChain *MIChainHead;
+
public:
Preprocessor(Diagnostic &diags, const LangOptions &opts,
const TargetInfo &target,
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 5e3b16e..ffdc6ae 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -33,8 +33,12 @@
if (!MICache.empty()) {
MI = MICache.back();
MICache.pop_back();
- } else
- MI = (MacroInfo*) BP.Allocate<MacroInfo>();
+ } else {
+ MacroInfoChain *MIChain = BP.Allocate<MacroInfoChain>();
+ MIChain->Next = MIChainHead;
+ MIChainHead = MIChain;
+ MI = &(MIChainHead->MI);
+ }
return MI;
}
diff --git a/lib/Lex/Preprocessor.cpp b/lib/Lex/Preprocessor.cpp
index 56ed765..9a69500 100644
--- a/lib/Lex/Preprocessor.cpp
+++ b/lib/Lex/Preprocessor.cpp
@@ -56,7 +56,7 @@
SourceMgr(SM), HeaderInfo(Headers), ExternalSource(0),
Identifiers(opts, IILookup), BuiltinInfo(Target), CodeComplete(0),
CodeCompletionFile(0), SkipMainFilePreamble(0, true), CurPPLexer(0),
- CurDirLookup(0), Callbacks(0), MacroArgCache(0), Record(0) {
+ CurDirLookup(0), Callbacks(0), MacroArgCache(0), Record(0), MIChainHead(0) {
ScratchBuf = new ScratchBuffer(SourceMgr);
CounterValue = 0; // __COUNTER__ starts at 0.
OwnsHeaderSearch = OwnsHeaders;
@@ -106,29 +106,10 @@
}
// Free any macro definitions.
- for (llvm::DenseMap<IdentifierInfo*, MacroInfo*>::iterator I =
- Macros.begin(), E = Macros.end(); I != E; ++I) {
- // We don't need to free the MacroInfo objects directly. These
- // will be released when the BumpPtrAllocator 'BP' object gets
- // destroyed. We still need to run the dtor, however, to free
- // memory alocated by MacroInfo.
- I->second->Destroy();
- I->first->setHasMacroDefinition(false);
- }
- for (std::vector<MacroInfo*>::iterator I = MICache.begin(),
- E = MICache.end(); I != E; ++I) {
- // We don't need to free the MacroInfo objects directly. These
- // will be released when the BumpPtrAllocator 'BP' object gets
- // destroyed. We still need to run the dtor, however, to free
- // memory alocated by MacroInfo.
- (*I)->Destroy();
- }
- for (llvm::DenseMap<IdentifierInfo*, std::vector<MacroInfo*> >::iterator I =
- PragmaPushMacroInfo.begin(), E = PragmaPushMacroInfo.end(); I!=E; ++I){
- for (std::vector<MacroInfo*>::iterator I2 = I->second.begin(), E2 = I->second.end();
- I2 != E2; ++I2) {
- (*I2)->Destroy();
- }
+ for (MacroInfoChain *I = MIChainHead ; I ; ) {
+ MacroInfoChain *Next = I->Next;
+ I->MI.Destroy();
+ I = Next;
}
// Free any cached macro expanders.