[PATCH] D120093: [memprof] Fix frame deserialization on big endian systems.

[Snehasish Kumar via Phabricator via llvm-commits]

snehasish updated this revision to Diff 409804.
snehasish added a comment.

Add comments for each field.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D120093/new/

https://reviews.llvm.org/D120093

Files:
  llvm/include/llvm/ProfileData/MemProf.h
  llvm/lib/ProfileData/MemProf.cpp


Index: llvm/lib/ProfileData/MemProf.cpp
===================================================================
--- llvm/lib/ProfileData/MemProf.cpp
+++ llvm/lib/ProfileData/MemProf.cpp
@@ -15,7 +15,7 @@
   for (const MemProfRecord &MR : Records) {
     LE.write<uint64_t>(MR.CallStack.size());
     for (const MemProfRecord::Frame &F : MR.CallStack) {
-      F.write(OS);
+      F.serialize(OS);
     }
     MR.Info.serialize(Schema, OS);
   }
@@ -33,8 +33,8 @@
     const uint64_t NumFrames =
         endian::readNext<uint64_t, little, unaligned>(Ptr);
     for (uint64_t J = 0; J < NumFrames; J++) {
-      const auto F = *reinterpret_cast<const MemProfRecord::Frame *>(Ptr);
-      Ptr += sizeof(MemProfRecord::Frame);
+      const auto F = MemProfRecord::Frame::deserialize(Ptr);
+      Ptr += MemProfRecord::Frame::serializedSize();
       MR.CallStack.push_back(F);
     }
     MR.Info.deserialize(Schema, Ptr);
Index: llvm/include/llvm/ProfileData/MemProf.h
===================================================================
--- llvm/include/llvm/ProfileData/MemProf.h
+++ llvm/include/llvm/ProfileData/MemProf.h
@@ -161,7 +161,7 @@
     bool operator!=(const Frame &Other) const { return !operator==(Other); }
 
     // Write the contents of the frame to the ostream \p OS.
-    void write(raw_ostream & OS) const {
+    void serialize(raw_ostream & OS) const {
       using namespace support;
 
       endian::Writer LE(OS, little);
@@ -176,6 +176,22 @@
       LE.write<uint32_t>(Column);
       LE.write<bool>(IsInlineFrame);
     }
+
+    // Read a frame from char data which has been serialized as little endian.
+    static Frame deserialize(const unsigned char *Ptr) {
+      using namespace support;
+      return Frame(
+          /*Function=*/endian::readNext<uint64_t, little, unaligned>(Ptr),
+          /*LineOffset=*/endian::readNext<uint32_t, little, unaligned>(Ptr),
+          /*Column=*/endian::readNext<uint32_t, little, unaligned>(Ptr),
+          /*IsInlineFrame*/ endian::readNext<bool, little, unaligned>(Ptr));
+    }
+
+    // Returns the size of the frame information.
+    static constexpr size_t serializedSize() {
+      return sizeof(Frame::Function) + sizeof(Frame::LineOffset) +
+             sizeof(Frame::Column) + sizeof(Frame::IsInlineFrame);
+    }
   });
 
   // The dynamic calling context for the allocation.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D120093.409804.patch
Type: text/x-patch
Size: 2355 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220217/658ba574/attachment.bin>