[memprof] Add another constructor to IndexedAllocationInfo (NFC) (#116684)

This patch adds another constructor to IndexedAllocationInfo that is
identical to the existing constructor except that the new one leaves
the CallStack field empty.

I'm planning to remove MemProf format Version 1.  Then we will migrate
the users of the existing constructor to the new one as nobody will be
using the CallStack field anymore.

Adding the new constructor now allows us to migrate a few existing
users of the old constructor even before we remove the CallStack
field.  In turn, that simplifies the patch to actually remove the
field.

Author: kazutakahirata

llvm/include/llvm/ProfileData/MemProf.h

@@ -354,10 +354,15 @@ struct IndexedAllocationInfo {
   PortableMemInfoBlock Info;
 
   IndexedAllocationInfo() = default;
+  // This constructor is soft deprecated.  It will be removed once we remove all
+  // users of the CallStack field.
   IndexedAllocationInfo(ArrayRef<FrameId> CS, CallStackId CSId,
                         const MemInfoBlock &MB,
                         const MemProfSchema &Schema = getFullSchema())
       : CallStack(CS), CSId(CSId), Info(MB, Schema) {}
+  IndexedAllocationInfo(CallStackId CSId, const MemInfoBlock &MB,
+                        const MemProfSchema &Schema = getFullSchema())
+      : CSId(CSId), Info(MB, Schema) {}
 
   // Returns the size in bytes when this allocation info struct is serialized.
   size_t serializedSize(const MemProfSchema &Schema,

llvm/unittests/ProfileData/InstrProfTest.cpp

@@ -415,8 +415,7 @@ makeRecordV2(std::initializer_list<::llvm::memprof::CallStackId> AllocFrames,
   for (const auto &CSId : AllocFrames)
     // We don't populate IndexedAllocationInfo::CallStack because we use it only
     // in Version1.
-    MR.AllocSites.emplace_back(::llvm::SmallVector<memprof::FrameId>(), CSId,
-                               Block, Schema);
+    MR.AllocSites.emplace_back(CSId, Block, Schema);
   for (const auto &CSId : CallSiteFrames)
     MR.CallSiteIds.push_back(CSId);
   return MR;

llvm/unittests/ProfileData/MemProfTest.cpp

@@ -315,7 +315,7 @@ TEST(MemProf, RecordSerializationRoundTripVerion2) {
   IndexedMemProfRecord Record;
   for (const auto &CSId : CallStackIds) {
     // Use the same info block for both allocation sites.
-    Record.AllocSites.emplace_back(llvm::SmallVector<FrameId>(), CSId, Info);
+    Record.AllocSites.emplace_back(CSId, Info);
   }
   Record.CallSiteIds.assign(CallSiteIds);
 
@@ -346,8 +346,7 @@ TEST(MemProf, RecordSerializationRoundTripVersion2HotColdSchema) {
   IndexedMemProfRecord Record;
   for (const auto &CSId : CallStackIds) {
     // Use the same info block for both allocation sites.
-    Record.AllocSites.emplace_back(llvm::SmallVector<FrameId>(), CSId, Info,
-                                   Schema);
+    Record.AllocSites.emplace_back(CSId, Info, Schema);
   }
   Record.CallSiteIds.assign(CallSiteIds);
 
@@ -510,7 +509,6 @@ TEST(MemProf, BaseMemProfReaderWithCSIdMap) {
   Block.AllocCount = 1U, Block.TotalAccessDensity = 4,
   Block.TotalLifetime = 200001;
   FakeRecord.AllocSites.emplace_back(
-      /*CS=*/llvm::SmallVector<FrameId>(),
       /*CSId=*/llvm::memprof::hashCallStack(CallStack),
       /*MB=*/Block);
   ProfData.insert({F1.hash(), FakeRecord});
@@ -610,7 +608,7 @@ MemInfoBlock makePartialMIB() {
 TEST(MemProf, MissingCallStackId) {
   // Use a non-existent CallStackId to trigger a mapping error in
   // toMemProfRecord.
-  llvm::memprof::IndexedAllocationInfo AI({}, 0xdeadbeefU, makePartialMIB(),
+  llvm::memprof::IndexedAllocationInfo AI(0xdeadbeefU, makePartialMIB(),
                                           llvm::memprof::getHotColdSchema());
 
   IndexedMemProfRecord IndexedMR;
@@ -633,7 +631,7 @@ TEST(MemProf, MissingCallStackId) {
 }
 
 TEST(MemProf, MissingFrameId) {
-  llvm::memprof::IndexedAllocationInfo AI({}, 0x222, makePartialMIB(),
+  llvm::memprof::IndexedAllocationInfo AI(0x222, makePartialMIB(),
                                           llvm::memprof::getHotColdSchema());
 
   IndexedMemProfRecord IndexedMR;