From 559c88b36d0647e9f6372a73de0c64b56408f42e Mon Sep 17 00:00:00 2001
From: "Daniel J. Hofmann" <daniel@trvx.org>
Date: Wed, 9 Nov 2016 00:23:38 +0100
Subject: [PATCH] Adds runtime alignment assertions, see #3267

---
 include/storage/shared_datatype.hpp |  1 +
 include/util/static_rtree.hpp       |  4 +++-
 src/contractor/contractor.cpp       | 20 +++++++++++++++++++-
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/include/storage/shared_datatype.hpp b/include/storage/shared_datatype.hpp
index f38799fda..e48ad3041 100644
--- a/include/storage/shared_datatype.hpp
+++ b/include/storage/shared_datatype.hpp
@@ -106,6 +106,7 @@ struct DataLayout
 
     template <typename T> inline void SetBlockSize(BlockID bid, uint64_t entries)
     {
+        static_assert(sizeof(T) % alignof(T) == 0, "aligned T* can't be used as an array pointer");
         num_entries[bid] = entries;
         entry_size[bid] = sizeof(T);
         entry_align[bid] = alignof(T);
diff --git a/include/util/static_rtree.hpp b/include/util/static_rtree.hpp
index f979cd515..44f2c0bc1 100644
--- a/include/util/static_rtree.hpp
+++ b/include/util/static_rtree.hpp
@@ -373,7 +373,9 @@ class StaticRTree
         {
             m_leaves_region.open(leaf_file);
             std::size_t num_leaves = m_leaves_region.size() / sizeof(LeafNode);
-            m_leaves.reset(reinterpret_cast<const LeafNode *>(m_leaves_region.data()), num_leaves);
+            auto data_ptr = m_leaves_region.data();
+            BOOST_ASSERT(reinterpret_cast<uintptr_t>(data_ptr) % alignof(LeafNode) == 0);
+            m_leaves.reset(reinterpret_cast<const LeafNode *>(data_ptr), num_leaves);
         }
         catch (const std::exception &exc)
         {
diff --git a/src/contractor/contractor.cpp b/src/contractor/contractor.cpp
index 9a7f38cc5..9fdced202 100644
--- a/src/contractor/contractor.cpp
+++ b/src/contractor/contractor.cpp
@@ -69,6 +69,15 @@ template <> struct hash<std::tuple<OSMNodeID, OSMNodeID, OSMNodeID>>
 };
 }
 
+namespace
+{
+template <typename T> inline bool is_aligned(const void *pointer)
+{
+    static_assert(sizeof(T) % alignof(T) == 0, "pointer can not be used as an array pointer");
+    return reinterpret_cast<uintptr_t>(pointer) % alignof(T) == 0;
+}
+}
+
 namespace osrm
 {
 namespace contractor
@@ -571,6 +580,7 @@ EdgeID Contractor::LoadEdgeExpandedGraph(
     };
 #pragma pack(pop, r1)
 
+    BOOST_ASSERT(is_aligned<EdgeBasedGraphHeader>(edge_based_graph_region.get_address()));
     const EdgeBasedGraphHeader graph_header =
         *(reinterpret_cast<const EdgeBasedGraphHeader *>(edge_based_graph_region.get_address()));
 
@@ -669,6 +679,7 @@ EdgeID Contractor::LoadEdgeExpandedGraph(
 
         auto region = mmap_file(rtree_leaf_filename.c_str());
         region.advise(mapped_region::advice_willneed);
+        BOOST_ASSERT(is_aligned<LeafNode>(region.get_address()));
 
         const auto bytes = region.get_size();
         const auto first = static_cast<const LeafNode *>(region.get_address());
@@ -850,16 +861,20 @@ EdgeID Contractor::LoadEdgeExpandedGraph(
 
     auto penaltyblock = reinterpret_cast<const extractor::lookup::PenaltyBlock *>(
         edge_penalty_region.get_address());
-    auto edge_segment_byte_ptr = reinterpret_cast<const char *>(edge_segment_region.get_address());
+    BOOST_ASSERT(is_aligned<extractor::lookup::PenaltyBlock>(penaltyblock));
+
     auto edge_based_edge_ptr = reinterpret_cast<extractor::EdgeBasedEdge *>(
         reinterpret_cast<char *>(edge_based_graph_region.get_address()) +
         sizeof(EdgeBasedGraphHeader));
+    BOOST_ASSERT(is_aligned<extractor::EdgeBasedEdge>(edge_based_edge_ptr));
 
     const auto edge_based_edge_last = reinterpret_cast<extractor::EdgeBasedEdge *>(
         reinterpret_cast<char *>(edge_based_graph_region.get_address()) +
         sizeof(EdgeBasedGraphHeader) +
         sizeof(extractor::EdgeBasedEdge) * graph_header.number_of_edges);
 
+    auto edge_segment_byte_ptr = reinterpret_cast<const char *>(edge_segment_region.get_address());
+
     while (edge_based_edge_ptr != edge_based_edge_last)
     {
         // Make a copy of the data from the memory map
@@ -869,8 +884,10 @@ EdgeID Contractor::LoadEdgeExpandedGraph(
         if (update_edge_weights || update_turn_penalties)
         {
             bool skip_this_edge = false;
+
             auto header = reinterpret_cast<const extractor::lookup::SegmentHeaderBlock *>(
                 edge_segment_byte_ptr);
+            BOOST_ASSERT(is_aligned<extractor::lookup::SegmentHeaderBlock>(header));
             edge_segment_byte_ptr += sizeof(extractor::lookup::SegmentHeaderBlock);
 
             auto previous_osm_node_id = header->previous_osm_node_id;
@@ -879,6 +896,7 @@ EdgeID Contractor::LoadEdgeExpandedGraph(
 
             auto segmentblocks =
                 reinterpret_cast<const extractor::lookup::SegmentBlock *>(edge_segment_byte_ptr);
+            BOOST_ASSERT(is_aligned<extractor::lookup::SegmentBlock>(segmentblocks));
             edge_segment_byte_ptr +=
                 sizeof(extractor::lookup::SegmentBlock) * (header->num_osm_nodes - 1);