[llvm] Replace OwningArrayRef with std::vector in BTFParser

[davidstone]

OwningArrayRef requires that the size and the capacity are the same. This prevents reusing memory allocations unless the size happens to be exactly the same (which is rare enough we don't even try). Switch to std::vector instead so that we're not repeatedly calling new[] and delete[].

[llvmbot]

@llvm/pr-subscribers-debuginfo

Author: David Stone (davidstone)

Changes

OwningArrayRef requires that the size and the capacity are the same. This prevents reusing memory allocations unless the size happens to be exactly the same (which is rare enough we don't even try). Switch to std::vector instead so that we're not repeatedly calling new[] and delete[].

---

Full diff: https://github.com/llvm/llvm-project/pull/169124.diff

2 Files Affected:

• (modified) llvm/include/llvm/DebugInfo/BTF/BTFParser.h (+1-1)
• (modified) llvm/lib/DebugInfo/BTF/BTFParser.cpp (+3-2)

diff --git a/llvm/include/llvm/DebugInfo/BTF/BTFParser.h b/llvm/include/llvm/DebugInfo/BTF/BTFParser.h
index f8b5b29738b3f..32644e6700e78 100644
--- a/llvm/include/llvm/DebugInfo/BTF/BTFParser.h
+++ b/llvm/include/llvm/DebugInfo/BTF/BTFParser.h
@@ -46,7 +46,7 @@ class BTFParser {
   // A copy of types table from the object file but using native byte
   // order. Should not be too big in practice, e.g. for ~250MiB vmlinux
   // image it is ~4MiB.
-  OwningArrayRef<uint8_t> TypesBuffer;
+  std::vector<uint8_t> TypesBuffer;
 
   // Maps ELF section number to instruction line number information.
   // Each BTFLinesVector is sorted by `InsnOffset` to allow fast lookups.
diff --git a/llvm/lib/DebugInfo/BTF/BTFParser.cpp b/llvm/lib/DebugInfo/BTF/BTFParser.cpp
index 4fc31a4456031..971a0d9f01769 100644
--- a/llvm/lib/DebugInfo/BTF/BTFParser.cpp
+++ b/llvm/lib/DebugInfo/BTF/BTFParser.cpp
@@ -206,7 +206,8 @@ Error BTFParser::parseTypesInfo(ParseContext &Ctx, uint64_t TypesInfoStart,
                                 StringRef RawData) {
   using support::endian::byte_swap;
 
-  TypesBuffer = OwningArrayRef<uint8_t>(arrayRefFromStringRef(RawData));
+  auto RawDataAsBytes = arrayRefFromStringRef(RawData);
+  TypesBuffer.assign(RawDataAsBytes.begin(), RawDataAsBytes.end());
   // Switch endianness if necessary.
   endianness Endianness = Ctx.Obj.isLittleEndian() ? llvm::endianness::little
                                                    : llvm::endianness::big;
@@ -380,7 +381,7 @@ Error BTFParser::parse(const ObjectFile &Obj, const ParseOptions &Opts) {
   SectionLines.clear();
   SectionRelocs.clear();
   Types.clear();
-  TypesBuffer = OwningArrayRef<uint8_t>();
+  TypesBuffer.clear();
 
   ParseContext Ctx(Obj, Opts);
   std::optional<SectionRef> BTF;

[github-actions]

🐧 Linux x64 Test Results

• 186457 tests passed
• 4866 tests skipped