[scudo] Make Options a reference for functions.

Modify all places that use the Options structure to be a const
reference. The underlying structure is a u32 so making it a
reference doesn't really do anything. However, if the structure
changes in the future it already works and avoids future coders
wondering why a structure is being passed by value. This also
makes it clear that the Options should not be modified in those functions.

Reviewed By: Chia-hungDuan

Differential Revision: https://reviews.llvm.org/D156372

Author: cferris1000

compiler-rt/lib/scudo/standalone/combined.h

@@ -299,7 +299,7 @@ class Allocator {
 #endif
   }
 
-  uptr computeOddEvenMaskForPointerMaybe(Options Options, uptr Ptr,
+  uptr computeOddEvenMaskForPointerMaybe(const Options &Options, uptr Ptr,
                                          uptr ClassId) {
     if (!Options.get(OptionBit::UseOddEvenTags))
       return 0;
@@ -1134,7 +1134,7 @@ class Allocator {
            reinterpret_cast<uptr>(Ptr) - SizeOrUnusedBytes;
   }
 
-  void quarantineOrDeallocateChunk(Options Options, void *TaggedPtr,
+  void quarantineOrDeallocateChunk(const Options &Options, void *TaggedPtr,
                                    Chunk::UnpackedHeader *Header,
                                    uptr Size) NO_THREAD_SAFETY_ANALYSIS {
     void *Ptr = getHeaderTaggedPointer(TaggedPtr);
@@ -1273,7 +1273,7 @@ class Allocator {
     storeEndMarker(RoundNewPtr, NewSize, BlockEnd);
   }
 
-  void storePrimaryAllocationStackMaybe(Options Options, void *Ptr) {
+  void storePrimaryAllocationStackMaybe(const Options &Options, void *Ptr) {
     if (!UNLIKELY(Options.get(OptionBit::TrackAllocationStacks)))
       return;
     auto *Ptr32 = reinterpret_cast<u32 *>(Ptr);
@@ -1305,7 +1305,7 @@ class Allocator {
     atomic_store_relaxed(&Entry->Ptr, reinterpret_cast<uptr>(Ptr));
   }
 
-  void storeSecondaryAllocationStackMaybe(Options Options, void *Ptr,
+  void storeSecondaryAllocationStackMaybe(const Options &Options, void *Ptr,
                                           uptr Size) {
     if (!UNLIKELY(Options.get(OptionBit::TrackAllocationStacks)))
       return;
@@ -1320,8 +1320,8 @@ class Allocator {
     storeRingBufferEntry(untagPointer(Ptr), Trace, Tid, Size, 0, 0);
   }
 
-  void storeDeallocationStackMaybe(Options Options, void *Ptr, u8 PrevTag,
-                                   uptr Size) {
+  void storeDeallocationStackMaybe(const Options &Options, void *Ptr,
+                                   u8 PrevTag, uptr Size) {
     if (!UNLIKELY(Options.get(OptionBit::TrackAllocationStacks)))
       return;
 

compiler-rt/lib/scudo/standalone/options.h

@@ -38,7 +38,7 @@ struct Options {
   }
 };
 
-template <typename Config> bool useMemoryTagging(Options Options) {
+template <typename Config> bool useMemoryTagging(const Options &Options) {
   return allocatorSupportsMemoryTagging<Config>() &&
          Options.get(OptionBit::UseMemoryTagging);
 }

compiler-rt/lib/scudo/standalone/secondary.h

@@ -90,7 +90,7 @@ template <typename Config> class MapAllocatorNoCache {
 public:
   void init(UNUSED s32 ReleaseToOsInterval) {}
   bool retrieve(UNUSED uptr Size, UNUSED CachedBlock &Entry) { return false; }
-  void store(UNUSED Options Options, LargeBlock::Header *H) { unmap(H); }
+  void store(UNUSED const Options &Options, LargeBlock::Header *H) { unmap(H); }
   bool canCache(UNUSED uptr Size) { return false; }
   void disable() {}
   void enable() {}
@@ -113,7 +113,7 @@ template <typename Config> class MapAllocatorNoCache {
 static const uptr MaxUnusedCachePages = 4U;
 
 template <typename Config>
-bool mapSecondary(Options Options, uptr CommitBase, uptr CommitSize,
+bool mapSecondary(const Options &Options, uptr CommitBase, uptr CommitSize,
                   uptr AllocPos, uptr Flags, MemMapT &MemMap) {
   Flags |= MAP_RESIZABLE;
   Flags |= MAP_ALLOWNOMEM;
@@ -179,7 +179,7 @@ template <typename Config> class MapAllocatorCache {
     setOption(Option::ReleaseInterval, static_cast<sptr>(ReleaseToOsInterval));
   }
 
-  void store(Options Options, LargeBlock::Header *H) EXCLUDES(Mutex) {
+  void store(const Options &Options, LargeBlock::Header *H) EXCLUDES(Mutex) {
     if (!canCache(H->CommitSize))
       return unmap(H);
 
@@ -407,11 +407,11 @@ template <typename Config> class MapAllocator {
       S->link(&Stats);
   }
 
-  void *allocate(Options Options, uptr Size, uptr AlignmentHint = 0,
+  void *allocate(const Options &Options, uptr Size, uptr AlignmentHint = 0,
                  uptr *BlockEnd = nullptr,
                  FillContentsMode FillContents = NoFill);
 
-  void deallocate(Options Options, void *Ptr);
+  void deallocate(const Options &Options, void *Ptr);
 
   static uptr getBlockEnd(void *Ptr) {
     auto *B = LargeBlock::getHeader<Config>(Ptr);
@@ -443,7 +443,7 @@ template <typename Config> class MapAllocator {
     }
   }
 
-  inline void setHeader(Options Options, CachedBlock &Entry,
+  inline void setHeader(const Options &Options, CachedBlock &Entry,
                         LargeBlock::Header *H, bool &Zeroed) {
     Zeroed = Entry.Time == 0;
     if (useMemoryTagging<Config>(Options)) {
@@ -501,8 +501,8 @@ template <typename Config> class MapAllocator {
 // the committed memory will amount to something close to Size - AlignmentHint
 // (pending rounding and headers).
 template <typename Config>
-void *MapAllocator<Config>::allocate(Options Options, uptr Size, uptr Alignment,
-                                     uptr *BlockEndPtr,
+void *MapAllocator<Config>::allocate(const Options &Options, uptr Size,
+                                     uptr Alignment, uptr *BlockEndPtr,
                                      FillContentsMode FillContents) {
   if (Options.get(OptionBit::AddLargeAllocationSlack))
     Size += 1UL << SCUDO_MIN_ALIGNMENT_LOG;
@@ -620,7 +620,7 @@ void *MapAllocator<Config>::allocate(Options Options, uptr Size, uptr Alignment,
 }
 
 template <typename Config>
-void MapAllocator<Config>::deallocate(Options Options, void *Ptr)
+void MapAllocator<Config>::deallocate(const Options &Options, void *Ptr)
     EXCLUDES(Mutex) {
   LargeBlock::Header *H = LargeBlock::getHeader<Config>(Ptr);
   const uptr CommitSize = H->CommitSize;