From adc795929a52d90ecced21a5279fe175a2a129b3 Mon Sep 17 00:00:00 2001
From: Philip Hyunsu Cho <chohyu01@cs.washington.edu>
Date: Thu, 30 Jan 2020 21:32:15 -0800
Subject: [PATCH] Fix compilation error due to 64-bit integer narrowing to
 size_t (#5250)

---
 src/c_api/c_api.cc | 2 +-
 src/learner.cc     | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/c_api/c_api.cc b/src/c_api/c_api.cc
index 756a90f73..85a49f3c6 100644
--- a/src/c_api/c_api.cc
+++ b/src/c_api/c_api.cc
@@ -311,7 +311,7 @@ XGB_DLL int XGDMatrixSliceDMatrixEx(DMatrixHandle handle,
   DMatrix* dmat = static_cast<std::shared_ptr<DMatrix>*>(handle)->get();
   CHECK(dynamic_cast<data::SimpleDMatrix*>(dmat))
       << "Slice only supported for SimpleDMatrix currently.";
-  data::DMatrixSliceAdapter adapter(dmat, {idxset, len});
+  data::DMatrixSliceAdapter adapter(dmat, {idxset, static_cast<size_t>(len)});
   *out = new std::shared_ptr<DMatrix>(
       DMatrix::Create(&adapter, std::numeric_limits<float>::quiet_NaN(), 1));
   API_END();
diff --git a/src/learner.cc b/src/learner.cc
index c3cca845e..b81af7751 100644
--- a/src/learner.cc
+++ b/src/learner.cc
@@ -670,9 +670,10 @@ class LearnerImpl : public Learner {
   for more details about differences between saving model and serializing.
 
 )doc";
-      int64_t json_offset {-1};
-      CHECK_EQ(fp.Read(&json_offset, sizeof(json_offset)), sizeof(json_offset));
-      CHECK_GT(json_offset, 0);
+      int64_t sz {-1};
+      CHECK_EQ(fp.Read(&sz, sizeof(sz)), sizeof(sz));
+      CHECK_GT(sz, 0);
+      size_t json_offset = static_cast<size_t>(sz);
       std::string buffer;
       common::FixedSizeStream{&fp}.Take(&buffer);