maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

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>.

llvm-svn: 116842
This commit is contained in:
Ted Kremenek 2010-10-19 18:16:54 +00:00
parent 6162f9774a
commit 1f1e4bdbf7
3 changed files with 21 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
clang/include/clang/Lex/Preprocessor.h
View File

@ -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 @@ private: // Cached tokens state.
/// 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,

8
clang/lib/Lex/PPDirectives.cpp
View File

@ -33,8 +33,12 @@ MacroInfo *Preprocessor::AllocateMacroInfo() {
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;
}

29
clang/lib/Lex/Preprocessor.cpp
View File

@ -56,7 +56,7 @@ Preprocessor::Preprocessor(Diagnostic &diags, const LangOptions &opts,
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 @@ Preprocessor::~Preprocessor() {
}
// 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.