[COFF] Move KeepUnique bit from Chunk to SectionChunk, NFC

The KeepUnique bit is used during ICF, which only operates on
SectionChunks, so only SectionChunks need it. This frees up a byte in
Chunk, which I plan to use in a follow-up change.

llvm-svn: 361549

2 files changed, 6 insertions, 8 deletions

diff --git a/lld/COFF/Chunks.h b/lld/COFF/Chunks.h
index 8525fee..d15638e 100644
--- a/lld/COFF/Chunks.h
+++ b/lld/COFF/Chunks.h
@@ -122,14 +122,9 @@ public:
 
 protected:
   Chunk(Kind K = OtherKind) : ChunkKind(K) {}
-  const Kind ChunkKind;
 
-public:
-  // Whether this section needs to be kept distinct from other sections during
-  // ICF. This is set by the driver using address-significance tables.
-  bool KeepUnique = false;
+  const Kind ChunkKind;
 
-protected:
   // The alignment of this chunk, stored in log2 form. The writer uses the
   // value.
   uint8_t P2Align = 0;
@@ -137,7 +132,6 @@ protected:
   // The RVA of this chunk in the output. The writer sets a value.
   uint32_t RVA = 0;
 
-protected:
   // The output section for this chunk.
   OutputSection *Out = nullptr;
 };
@@ -283,6 +277,10 @@ public:
   // Used by the garbage collector.
   bool Live;
 
+  // Whether this section needs to be kept distinct from other sections during
+  // ICF. This is set by the driver using address-significance tables.
+  bool KeepUnique = false;
+
   // The COMDAT selection if this is a COMDAT chunk.
   llvm::COFF::COMDATType Selection = (llvm::COFF::COMDATType)0;
 
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 39d476c..0069843 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -858,7 +858,7 @@ static void parseOrderFile(StringRef Arg) {
 
 static void markAddrsig(Symbol *S) {
   if (auto *D = dyn_cast_or_null<Defined>(S))
-    if (Chunk *C = D->getChunk())
+    if (SectionChunk *C = dyn_cast_or_null<SectionChunk>(D->getChunk()))
       C->KeepUnique = true;
 }