[clang][extract-api] Stop allocating APIRecords via BumpPtrAllocator

Using a BumpPtrAllocator introduced memory leaks for APIRecords as they
contain a std::vector. This meant that we needed to always keep a
reference to the records in APISet and arrange for their destructor to
get called appropriately. This was further complicated by the need for
records to own sub-records as these subrecords would still need to be
allocated via the BumpPtrAllocator and the owning record would now need
to arrange for the destructor of its subrecords to be called
appropriately.

Since APIRecords contain a std::vector so whenever elements get added to
that there is an associated heap allocation regardless. Since
performance isn't currently our main priority it makes sense to use
regular unique_ptr to keep track of APIRecords, this way we don't need
to arrange for destructors to get called.

The BumpPtrAllocator is still used for strings such as USRs so that we
can easily de-duplicate them as necessary.

Differential Revision: https://reviews.llvm.org/D122331

1 files changed, 13 insertions, 15 deletions

diff --git a/clang/lib/ExtractAPI/API.cpp b/clang/lib/ExtractAPI/API.cpp
index 7aa8233..6b60d2c 100644
--- a/clang/lib/ExtractAPI/API.cpp
+++ b/clang/lib/ExtractAPI/API.cpp
@@ -17,7 +17,7 @@
 #include "clang/AST/CommentLexer.h"
 #include "clang/AST/RawCommentList.h"
 #include "clang/Index/USRGeneration.h"
-#include "llvm/Support/Allocator.h"
+#include <memory>
 
 using namespace clang::extractapi;
 using namespace llvm;
@@ -32,9 +32,9 @@ GlobalRecord *APISet::addGlobal(GVKind Kind, StringRef Name, StringRef USR,
   auto Result = Globals.insert({Name, nullptr});
   if (Result.second) {
     // Create the record if it does not already exist.
-    auto Record = APIRecordUniquePtr<GlobalRecord>(new (Allocator) GlobalRecord{
+    auto Record = std::make_unique<GlobalRecord>(
         Kind, Name, USR, Loc, Availability, Linkage, Comment, Fragments,
-        SubHeading, Signature});
+        SubHeading, Signature);
     Result.first->second = std::move(Record);
   }
   return Result.first->second.get();
@@ -63,9 +63,8 @@ EnumConstantRecord *APISet::addEnumConstant(
     EnumRecord *Enum, StringRef Name, StringRef USR, PresumedLoc Loc,
     const AvailabilityInfo &Availability, const DocComment &Comment,
     DeclarationFragments Declaration, DeclarationFragments SubHeading) {
-  auto Record =
-      APIRecordUniquePtr<EnumConstantRecord>(new (Allocator) EnumConstantRecord{
-          Name, USR, Loc, Availability, Comment, Declaration, SubHeading});
+  auto Record = std::make_unique<EnumConstantRecord>(
+      Name, USR, Loc, Availability, Comment, Declaration, SubHeading);
   return Enum->Constants.emplace_back(std::move(Record)).get();
 }
 
@@ -77,8 +76,8 @@ EnumRecord *APISet::addEnum(StringRef Name, StringRef USR, PresumedLoc Loc,
   auto Result = Enums.insert({Name, nullptr});
   if (Result.second) {
     // Create the record if it does not already exist.
-    auto Record = APIRecordUniquePtr<EnumRecord>(new (Allocator) EnumRecord{
-        Name, USR, Loc, Availability, Comment, Declaration, SubHeading});
+    auto Record = std::make_unique<EnumRecord>(
+        Name, USR, Loc, Availability, Comment, Declaration, SubHeading);
     Result.first->second = std::move(Record);
   }
   return Result.first->second.get();
@@ -90,9 +89,8 @@ StructFieldRecord *APISet::addStructField(StructRecord *Struct, StringRef Name,
                                           const DocComment &Comment,
                                           DeclarationFragments Declaration,
                                           DeclarationFragments SubHeading) {
-  auto Record =
-      APIRecordUniquePtr<StructFieldRecord>(new (Allocator) StructFieldRecord{
-          Name, USR, Loc, Availability, Comment, Declaration, SubHeading});
+  auto Record = std::make_unique<StructFieldRecord>(
+      Name, USR, Loc, Availability, Comment, Declaration, SubHeading);
   return Struct->Fields.emplace_back(std::move(Record)).get();
 }
 
@@ -104,8 +102,8 @@ StructRecord *APISet::addStruct(StringRef Name, StringRef USR, PresumedLoc Loc,
   auto Result = Structs.insert({Name, nullptr});
   if (Result.second) {
     // Create the record if it does not already exist.
-    auto Record = APIRecordUniquePtr<StructRecord>(new (Allocator) StructRecord{
-        Name, USR, Loc, Availability, Comment, Declaration, SubHeading});
+    auto Record = std::make_unique<StructRecord>(
+        Name, USR, Loc, Availability, Comment, Declaration, SubHeading);
     Result.first->second = std::move(Record);
   }
   return Result.first->second.get();
@@ -122,10 +120,10 @@ StringRef APISet::copyString(StringRef String) {
     return {};
 
   // No need to allocate memory and copy if the string has already been stored.
-  if (Allocator.identifyObject(String.data()))
+  if (StringAllocator.identifyObject(String.data()))
     return String;
 
-  void *Ptr = Allocator.Allocate(String.size(), 1);
+  void *Ptr = StringAllocator.Allocate(String.size(), 1);
   memcpy(Ptr, String.data(), String.size());
   return StringRef(reinterpret_cast<const char *>(Ptr), String.size());
 }