llvm-profdata: Reduce memory usage by using Error callback rather than member

Reduces llvm-profdata memory usage on a large profile from 7.8GB to 5.1GB.

The ProfData API now supports reporting all the errors/warnings rather
than only the first, though llvm-profdata ignores everything after the
first for now to preserve existing behavior. (if there's a desire for
other behavior, happy to implement that - but might be as well left for
a separate patch)

Reviewers: davidxl

Differential Revision: https://reviews.llvm.org/D35149

llvm-svn: 307516

1 files changed, 16 insertions, 3 deletions

diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profdata/llvm-profdata.cpp
index bcc16f364a2..f7d1c622f8f 100644
--- a/llvm/tools/llvm-profdata/llvm-profdata.cpp
+++ b/llvm/tools/llvm-profdata/llvm-profdata.cpp
@@ -159,14 +159,20 @@ static void loadInput(const WeightedFile &Input, WriterContext *WC) {
 
   for (auto &I : *Reader) {
     const StringRef FuncName = I.Name;
-    if (Error E = WC->Writer.addRecord(std::move(I), Input.Weight)) {
+    bool Reported = false;
+    WC->Writer.addRecord(std::move(I), Input.Weight, [&](Error E) {
+      if (Reported) {
+        consumeError(std::move(E));
+        return;
+      }
+      Reported = true;
       // Only show hint the first time an error occurs.
       instrprof_error IPE = InstrProfError::take(std::move(E));
       std::unique_lock<std::mutex> ErrGuard{WC->ErrLock};
       bool firstTime = WC->WriterErrorCodes.insert(IPE).second;
       handleMergeWriterError(make_error<InstrProfError>(IPE), Input.Filename,
                              FuncName, firstTime);
-    }
+    });
   }
   if (Reader->hasError())
     WC->Err = Reader->getError();
@@ -174,8 +180,15 @@ static void loadInput(const WeightedFile &Input, WriterContext *WC) {
 
 /// Merge the \p Src writer context into \p Dst.
 static void mergeWriterContexts(WriterContext *Dst, WriterContext *Src) {
-  if (Error E = Dst->Writer.mergeRecordsFromWriter(std::move(Src->Writer)))
+  bool Reported = false;
+  Dst->Writer.mergeRecordsFromWriter(std::move(Src->Writer), [&](Error E) {
+    if (Reported) {
+      consumeError(std::move(E));
+      return;
+    }
+    Reported = true;
     Dst->Err = std::move(E);
+  });
 }
 
 static void mergeInstrProfile(const WeightedFileVector &Inputs,