Merge pull request #27388 from jckarter/reflection-remove-start-addresses

swift-reflection-dump: Virtualize logical-to-physical address mapping.

Author: jckarter

include/swift/Reflection/ReflectionContext.h

@@ -237,18 +237,13 @@ class ReflectionContext
         ReflStrMdSec.first == nullptr)
       return false;
 
-    auto LocalStartAddress = reinterpret_cast<uint64_t>(SectBuf.get());
-    auto RemoteStartAddress = static_cast<uint64_t>(RangeStart);
-
     ReflectionInfo info = {
         {FieldMdSec.first, FieldMdSec.second},
         {AssocTySec.first, AssocTySec.second},
         {BuiltinTySec.first, BuiltinTySec.second},
         {CaptureSec.first, CaptureSec.second},
         {TypeRefMdSec.first, TypeRefMdSec.second},
-        {ReflStrMdSec.first, ReflStrMdSec.second},
-        LocalStartAddress,
-        RemoteStartAddress};
+        {ReflStrMdSec.first, ReflStrMdSec.second}};
 
     this->addReflectionInfo(info);
 
@@ -346,19 +341,13 @@ class ReflectionContext
         ReflStrMdSec.first == nullptr)
       return false;
 
-    auto LocalStartAddress = reinterpret_cast<uintptr_t>(DOSHdrBuf.get());
-    auto RemoteStartAddress =
-        static_cast<uintptr_t>(ImageStart.getAddressData());
-
     ReflectionInfo Info = {
         {FieldMdSec.first, FieldMdSec.second},
         {AssocTySec.first, AssocTySec.second},
         {BuiltinTySec.first, BuiltinTySec.second},
         {CaptureSec.first, CaptureSec.second},
         {TypeRefMdSec.first, TypeRefMdSec.second},
-        {ReflStrMdSec.first, ReflStrMdSec.second},
-        LocalStartAddress,
-        RemoteStartAddress};
+        {ReflStrMdSec.first, ReflStrMdSec.second}};
     this->addReflectionInfo(Info);
     return true;
   }
@@ -466,19 +455,13 @@ class ReflectionContext
         ReflStrMdSec.first == nullptr)
       return false;
 
-    auto LocalStartAddress = reinterpret_cast<uint64_t>(Buf.get());
-    auto RemoteStartAddress =
-        static_cast<uint64_t>(ImageStart.getAddressData());
-
     ReflectionInfo info = {
         {FieldMdSec.first, FieldMdSec.second},
         {AssocTySec.first, AssocTySec.second},
         {BuiltinTySec.first, BuiltinTySec.second},
         {CaptureSec.first, CaptureSec.second},
         {TypeRefMdSec.first, TypeRefMdSec.second},
-        {ReflStrMdSec.first, ReflStrMdSec.second},
-        LocalStartAddress,
-        RemoteStartAddress};
+        {ReflStrMdSec.first, ReflStrMdSec.second}};
 
     this->addReflectionInfo(info);
 

include/swift/Reflection/TypeRefBuilder.h

@@ -203,9 +203,6 @@ struct ReflectionInfo {
   CaptureSection Capture;
   GenericSection TypeReference;
   GenericSection ReflectionString;
-
-  uint64_t LocalStartAddress;
-  uint64_t RemoteStartAddress;
 };
 
 struct ClosureContextInfo {

lib/Demangling/NodePrinter.cpp

@@ -79,19 +79,18 @@ static DemanglerPrinter &operator<<(DemanglerPrinter &printer,
     case '\n': printer << "\\n"; break;
     case '\r': printer << "\\r"; break;
     case '"': printer << "\\\""; break;
-    case '\'': printer << '\''; break; // no need to escape these
     case '\0': printer << "\\0"; break;
     default:
-      auto c = static_cast<char>(C);
-      // Other ASCII control characters should get escaped.
-      if (c < 0x20 || c == 0x7F) {
+      auto c = static_cast<unsigned char>(C);
+      // Other control or high-bit characters should get escaped.
+      if (c < 0x20 || c >= 0x7F) {
         static const char Hexdigit[] = {
           '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
           'A', 'B', 'C', 'D', 'E', 'F'
         };
         printer << "\\x" << Hexdigit[c >> 4] << Hexdigit[c & 0xF];
       } else {
-        printer << c;
+        printer << (char)c;
       }
       break;
     }

stdlib/public/Reflection/TypeRefBuilder.cpp

@@ -268,15 +268,13 @@ TypeRefBuilder::getBuiltinTypeInfo(const TypeRef *TR) {
   return nullptr;
 }
 
-// TODO: This can probably be eliminated.
 RemoteRef<CaptureDescriptor>
 TypeRefBuilder::getCaptureDescriptor(uint64_t RemoteAddress) {
   for (auto Info : ReflectionInfos) {
     for (auto CD : Info.Capture) {
-      auto OtherAddr = (reinterpret_cast<uint64_t>(CD.getLocalBuffer()) -
-                        Info.LocalStartAddress + Info.RemoteStartAddress);
-      if (OtherAddr == RemoteAddress)
+      if (RemoteAddress == CD.getAddressData()) {
         return CD;
+      }
     }
   }
 

stdlib/public/SwiftRemoteMirror/SwiftRemoteMirror.cpp

@@ -149,10 +149,7 @@ swift_reflection_addReflectionInfo(SwiftReflectionContextRef ContextRef,
     sectionFromInfo<BuiltinTypeDescriptorIterator>(Info, Info.builtin_types),
     sectionFromInfo<CaptureDescriptorIterator>(Info, Info.capture),
     sectionFromInfo<const void *>(Info, Info.type_references),
-    sectionFromInfo<const void *>(Info, Info.reflection_strings),
-    Info.LocalStartAddress,
-    Info.RemoteStartAddress
-  };
+    sectionFromInfo<const void *>(Info, Info.reflection_strings)};
 
   Context->addReflectionInfo(ContextInfo);
 }

tools/swift-reflection-dump/swift-reflection-dump.cpp

@@ -122,44 +122,72 @@ static bool needToRelocate(SectionRef S) {
 
 
 class Image {
-  std::vector<char> Memory;
+  const ObjectFile *O;
+  uint64_t VASize;
 
-public:
-  explicit Image(const ObjectFile *O) {
-    uint64_t VASize = O->getData().size();
-    for (SectionRef S : O->sections()) {
-      if (auto SectionAddr = getSectionAddress(S))
-        VASize = std::max(VASize, SectionAddr + S.getSize());
-    }
-    Memory.resize(VASize);
-    std::memcpy(&Memory[0], O->getData().data(), O->getData().size());
+  struct RelocatedRegion {
+    uint64_t Start, Size;
+    const char *Base;
+  };
 
+  std::vector<RelocatedRegion> RelocatedRegions;
+
+public:
+  explicit Image(const ObjectFile *O) : O(O), VASize(O->getData().size()) {
     for (SectionRef S : O->sections()) {
       if (!needToRelocate(S))
         continue;
       StringRef Content;
+      auto SectionAddr = getSectionAddress(S);
+      if (SectionAddr)
+        VASize = std::max(VASize, SectionAddr + S.getSize());
+
       if (auto EC = S.getContents(Content))
         reportError(EC);
-      std::memcpy(&Memory[getSectionAddress(S)], Content.data(),
-                  Content.size());
+
+      auto PhysOffset = (uintptr_t)Content.data() - (uintptr_t)O->getData().data();
+      
+      if (PhysOffset == SectionAddr) {
+        continue;
+      }
+
+      RelocatedRegions.push_back(RelocatedRegion{
+        SectionAddr,
+        Content.size(),
+        Content.data()});
     }
   }
 
   RemoteAddress getStartAddress() const {
-    return RemoteAddress((uintptr_t)Memory.data());
+    return RemoteAddress((uintptr_t)O->getData().data());
   }
 
   bool isAddressValid(RemoteAddress Addr, uint64_t Size) const {
-    return (uintptr_t)Memory.data() <= Addr.getAddressData() &&
-           Addr.getAddressData() + Size <=
-               (uintptr_t)Memory.data() + Memory.size();
+    auto start = getStartAddress().getAddressData();
+    return start <= Addr.getAddressData()
+      && Addr.getAddressData() + Size <= start + VASize;
   }
 
   ReadBytesResult readBytes(RemoteAddress Addr, uint64_t Size) {
     if (!isAddressValid(Addr, Size))
       return ReadBytesResult(nullptr, [](const void *) {});
-    return ReadBytesResult((const void *)(Addr.getAddressData()),
-                           [](const void *) {});
+    
+    auto addrValue = Addr.getAddressData();
+    auto base = O->getData().data();
+    auto offset = addrValue - (uint64_t)base;
+    for (auto &region : RelocatedRegions) {
+      if (region.Start <= offset && offset < region.Start + region.Size) {
+        // Read shouldn't need to straddle section boundaries.
+        if (offset + Size > region.Start + region.Size)
+          return ReadBytesResult(nullptr, [](const void *) {});
+
+        offset -= region.Start;
+        base = region.Base;
+        break;
+      }
+    }
+    
+    return ReadBytesResult(base + offset, [](const void *) {});
   }
 };