Really^2 fix <rdar://problem/8361834>, this time without crashing.
Now MICache is a linked list (per the FIXME), where we tradeoff between MacroInfo objects being in MICache
and MIChainHead. MacroInfo objects in the MICache chain are already "Destroy()'ed", so they can be reused. When
inserting into MICache, we need to remove them from the regular linked list so that they aren't destroyed more than
once.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116869 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index b958d9e..8f66d99 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -28,18 +28,23 @@
//===----------------------------------------------------------------------===//
MacroInfo *Preprocessor::AllocateMacroInfo() {
- MacroInfo *MI;
+ MacroInfoChain *MIChain;
- if (!MICache.empty()) {
- MI = MICache.back();
- MICache.pop_back();
- } else {
- MacroInfoChain *MIChain = BP.Allocate<MacroInfoChain>();
- MIChain->Next = MIChainHead;
- MIChainHead = MIChain;
- MI = &(MIChain->MI);
+ if (MICache) {
+ MIChain = MICache;
+ MICache = MICache->Next;
}
- return MI;
+ else {
+ MIChain = BP.Allocate<MacroInfoChain>();
+ }
+
+ MIChain->Next = MIChainHead;
+ MIChain->Prev = 0;
+ if (MIChainHead)
+ MIChainHead->Prev = MIChain;
+ MIChainHead = MIChain;
+
+ return &(MIChain->MI);
}
MacroInfo *Preprocessor::AllocateMacroInfo(SourceLocation L) {
@@ -57,10 +62,23 @@
/// ReleaseMacroInfo - Release the specified MacroInfo. This memory will
/// be reused for allocating new MacroInfo objects.
void Preprocessor::ReleaseMacroInfo(MacroInfo *MI) {
- MICache.push_back(MI);
- MI->FreeArgumentList();
-}
+ MacroInfoChain *MIChain = (MacroInfoChain*) MI;
+ if (MacroInfoChain *Prev = MIChain->Prev) {
+ MacroInfoChain *Next = MIChain->Next;
+ Prev->Next = Next;
+ if (Next)
+ Next->Prev = Prev;
+ }
+ else {
+ assert(MIChainHead == MIChain);
+ MIChainHead = MIChain->Next;
+ MIChainHead->Prev = 0;
+ }
+ MIChain->Next = MICache;
+ MICache = MIChain;
+ MI->Destroy();
+}
/// DiscardUntilEndOfDirective - Read and discard all tokens remaining on the
/// current line until the tok::eom token is found.