Revert "Allocate RuntimeType objects on Frozen Object Heap

src/coreclr/inc/clrconfigvalues.h

@@ -404,6 +404,11 @@ CONFIG_DWORD_INFO(INTERNAL_LoaderHeapCallTracing, W("LoaderHeapCallTracing"), 0,
 RETAIL_CONFIG_DWORD_INFO(INTERNAL_CodeHeapReserveForJumpStubs, W("CodeHeapReserveForJumpStubs"), 1, "Percentage of code heap to reserve for jump stubs")
 RETAIL_CONFIG_DWORD_INFO(INTERNAL_BreakOnOutOfMemoryWithinRange, W("BreakOnOutOfMemoryWithinRange"), 0, "Break before out of memory within range exception is thrown")
 
+///
+/// Frozen segments (aka Frozen Object Heap)
+///
+RETAIL_CONFIG_DWORD_INFO(INTERNAL_UseFrozenObjectHeap, W("UseFrozenObjectHeap"), 1, "Use frozen object heap for certain types of objects (e.g. string literals) as an optimization.")
+
 ///
 /// Log
 ///

src/coreclr/inc/corinfo.h

@@ -2265,13 +2265,6 @@ class ICorStaticInfo
             int                         bufferSize  /* IN  */
             ) = 0;
 
-    // Calls ToString() for given pinned/frozen object handle
-    virtual int objectToString (
-            void*                       handle,     /* IN  */
-            char*                       buffer,     /* OUT */
-            int                         bufferSize  /* IN  */
-            ) = 0;
-
     /**********************************************************************************/
     //
     // ICorClassInfo
@@ -2482,10 +2475,6 @@ class ICorStaticInfo
             CORINFO_CLASS_HANDLE        cls
             ) = 0;
 
-    virtual void* getRuntimeTypePointer(
-            CORINFO_CLASS_HANDLE        cls
-            ) = 0;
-
     virtual bool getReadyToRunHelper(
             CORINFO_RESOLVED_TOKEN *        pResolvedToken,
             CORINFO_LOOKUP_KIND *           pGenericLookupKind,

src/coreclr/inc/crsttypes.h

@@ -132,8 +132,7 @@ enum CrstType
     CrstVSDIndirectionCellLock = 114,
     CrstWrapperTemplate = 115,
     CrstFrozenObjectHeap = 116,
-    CrstMethodTableExposedObject = 117,
-    kNumberOfCrstTypes = 118
+    kNumberOfCrstTypes = 117
 };
 
 #endif // __CRST_TYPES_INCLUDED
@@ -260,8 +259,7 @@ int g_rgCrstLevelMap[] =
     3,          // CrstUnwindInfoTableLock
     4,          // CrstVSDIndirectionCellLock
     3,          // CrstWrapperTemplate
-    -1,         // CrstFrozenObjectHeap
-    -1,         // CrstMethodTableExposedObject
+    0,          // CrstFrozenObjectHeap
 };
 
 // An array mapping CrstType to a stringized name.
@@ -383,8 +381,7 @@ LPCSTR g_rgCrstNameMap[] =
     "CrstUnwindInfoTableLock",
     "CrstVSDIndirectionCellLock",
     "CrstWrapperTemplate",
-    "CrstFrozenObjectHeap",
-    "CrstMethodTableExposedObject"
+    "CrstFrozenObjectHeap"
 };
 
 // Define a special level constant for unordered locks.

src/coreclr/inc/icorjitinfoimpl_generated.h

@@ -175,11 +175,6 @@ int getStringLiteral(
           char16_t* buffer,
           int bufferSize) override;
 
-int objectToString(
-          void* handle,
-          char* buffer,
-          int bufferSize) override;
-
 CorInfoType asCorInfoType(
           CORINFO_CLASS_HANDLE cls) override;
 
@@ -285,9 +280,6 @@ CorInfoHelpFunc getBoxHelper(
 CorInfoHelpFunc getUnBoxHelper(
           CORINFO_CLASS_HANDLE cls) override;
 
-void* getRuntimeTypePointer(
-          CORINFO_CLASS_HANDLE cls) override;
-
 bool getReadyToRunHelper(
           CORINFO_RESOLVED_TOKEN* pResolvedToken,
           CORINFO_LOOKUP_KIND* pGenericLookupKind,

src/coreclr/inc/jiteeversionguid.h

@@ -43,11 +43,11 @@ typedef const GUID *LPCGUID;
 #define GUID_DEFINED
 #endif // !GUID_DEFINED
 
-constexpr GUID JITEEVersionIdentifier = { /* 11b4ea58-c400-4c3d-995e-4e2f0676f6e8 */
-    0x11b4ea58,
-    0xc400,
-    0x4c3d,
-    {0x99, 0x5e, 0x4e, 0x2f, 0x6, 0x76, 0xf6, 0xe8}
+constexpr GUID JITEEVersionIdentifier = { /* eb8352bd-0a13-4b5b-badb-58f9ecc40c44 */
+    0xeb8352bd,
+    0x0a13,
+    0x4b5b,
+    {0xba, 0xdb, 0x58, 0xf9, 0xec, 0xc4, 0x0c, 0x44}
   };
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////

src/coreclr/jit/ICorJitInfo_API_names.h

@@ -41,7 +41,6 @@ DEF_CLR_API(getTokenTypeAsHandle)
 DEF_CLR_API(isValidToken)
 DEF_CLR_API(isValidStringRef)
 DEF_CLR_API(getStringLiteral)
-DEF_CLR_API(objectToString)
 DEF_CLR_API(asCorInfoType)
 DEF_CLR_API(getClassName)
 DEF_CLR_API(getClassNameFromMetadata)
@@ -71,7 +70,6 @@ DEF_CLR_API(getSharedCCtorHelper)
 DEF_CLR_API(getTypeForBox)
 DEF_CLR_API(getBoxHelper)
 DEF_CLR_API(getUnBoxHelper)
-DEF_CLR_API(getRuntimeTypePointer)
 DEF_CLR_API(getReadyToRunHelper)
 DEF_CLR_API(getReadyToRunDelegateCtorHelper)
 DEF_CLR_API(getHelperName)

src/coreclr/jit/ICorJitInfo_API_wrapper.hpp

@@ -374,17 +374,6 @@ int WrapICorJitInfo::getStringLiteral(
     return temp;
 }
 
-int WrapICorJitInfo::objectToString(
-          void* handle,
-          char* buffer,
-          int bufferSize)
-{
-    API_ENTER(objectToString);
-    int temp = wrapHnd->objectToString(handle, buffer, bufferSize);
-    API_LEAVE(objectToString);
-    return temp;
-}
-
 CorInfoType WrapICorJitInfo::asCorInfoType(
           CORINFO_CLASS_HANDLE cls)
 {
@@ -663,15 +652,6 @@ CorInfoHelpFunc WrapICorJitInfo::getUnBoxHelper(
     return temp;
 }
 
-void* WrapICorJitInfo::getRuntimeTypePointer(
-          CORINFO_CLASS_HANDLE cls)
-{
-    API_ENTER(getRuntimeTypePointer);
-    void* temp = wrapHnd->getRuntimeTypePointer(cls);
-    API_LEAVE(getRuntimeTypePointer);
-    return temp;
-}
-
 bool WrapICorJitInfo::getReadyToRunHelper(
           CORINFO_RESOLVED_TOKEN* pResolvedToken,
           CORINFO_LOOKUP_KIND* pGenericLookupKind,

src/coreclr/jit/assertionprop.cpp

@@ -2149,7 +2149,7 @@ void Compiler::optDebugCheckAssertion(AssertionDsc* assertion)
                     break;
                 case O1K_LCLVAR:
                     assert((lvaGetDesc(assertion->op1.lcl.lclNum)->lvType != TYP_REF) ||
-                           (assertion->op2.u1.iconVal == 0) || doesMethodHaveFrozenObjects());
+                           (assertion->op2.u1.iconVal == 0) || doesMethodHaveFrozenString());
                     break;
                 case O1K_VALUE_NUMBER:
                     assert((vnStore->TypeOfVN(assertion->op1.vn) != TYP_REF) || (assertion->op2.u1.iconVal == 0));
@@ -3423,7 +3423,7 @@ GenTree* Compiler::optConstantAssertionProp(AssertionDsc*        curAssertion,
 
                 // Make sure we don't retype const gc handles to TYP_I_IMPL
                 // Although, it's possible for e.g. GTF_ICON_STATIC_HDL
-                if (!newTree->IsIntegralConst(0) && newTree->IsIconHandle(GTF_ICON_OBJ_HDL))
+                if (!newTree->IsIntegralConst(0) && newTree->IsIconHandle(GTF_ICON_STR_HDL))
                 {
                     if (tree->TypeIs(TYP_BYREF))
                     {

src/coreclr/jit/compiler.cpp

@@ -9413,11 +9413,6 @@ void cTreeFlags(Compiler* comp, GenTree* tree)
                         chars += printf("[ICON_STR_HDL]");
                         break;
 
-                    case GTF_ICON_OBJ_HDL:
-
-                        chars += printf("[ICON_OBJ_HDL]");
-                        break;
-
                     case GTF_ICON_CONST_PTR:
 
                         chars += printf("[ICON_CONST_PTR]");

src/coreclr/jit/compiler.h

@@ -6803,7 +6803,7 @@ class Compiler
 #define OMF_HAS_EXPRUNTIMELOOKUP               0x00000080 // Method contains a runtime lookup to an expandable dictionary.
 #define OMF_HAS_PATCHPOINT                     0x00000100 // Method contains patchpoints
 #define OMF_NEEDS_GCPOLLS                      0x00000200 // Method needs GC polls
-#define OMF_HAS_FROZEN_OBJECTS                 0x00000400 // Method has frozen objects (REF constant int)
+#define OMF_HAS_FROZEN_STRING                  0x00000400 // Method has a frozen string (REF constant int), currently only on NativeAOT.
 #define OMF_HAS_PARTIAL_COMPILATION_PATCHPOINT 0x00000800 // Method contains partial compilation patchpoints
 #define OMF_HAS_TAILCALL_SUCCESSOR             0x00001000 // Method has potential tail call in a non BBJ_RETURN block
 #define OMF_HAS_MDNEWARRAY                     0x00002000 // Method contains 'new' of an MD array
@@ -6828,14 +6828,14 @@ class Compiler
 
     void addFatPointerCandidate(GenTreeCall* call);
 
-    bool doesMethodHaveFrozenObjects() const
+    bool doesMethodHaveFrozenString() const
     {
-        return (optMethodFlags & OMF_HAS_FROZEN_OBJECTS) != 0;
+        return (optMethodFlags & OMF_HAS_FROZEN_STRING) != 0;
     }
 
-    void setMethodHasFrozenObjects()
+    void setMethodHasFrozenString()
     {
-        optMethodFlags |= OMF_HAS_FROZEN_OBJECTS;
+        optMethodFlags |= OMF_HAS_FROZEN_STRING;
     }
 
     bool doesMethodHaveGuardedDevirtualization() const
@@ -7798,7 +7798,7 @@ class Compiler
     const char* eeGetFieldName(CORINFO_FIELD_HANDLE fieldHnd, const char** classNamePtr = nullptr);
 
 #if defined(DEBUG)
-    void eePrintFrozenObjectDescription(const char* prefix, size_t handle);
+    const WCHAR* eeGetCPString(size_t stringHandle);
     unsigned eeTryGetClassSize(CORINFO_CLASS_HANDLE clsHnd);
     const char16_t* eeGetShortClassName(CORINFO_CLASS_HANDLE clsHnd);
 #endif

src/coreclr/jit/ee_il_dll.cpp

@@ -1615,40 +1615,45 @@ const char16_t* Compiler::eeGetShortClassName(CORINFO_CLASS_HANDLE clsHnd)
     return param.classNameWidePtr;
 }
 
-void Compiler::eePrintFrozenObjectDescription(const char* prefix, size_t handle)
+const WCHAR* Compiler::eeGetCPString(size_t strHandle)
 {
-    const int maxStrSize = 64;
-    char      str[maxStrSize];
-    int       realLength = this->info.compCompHnd->objectToString((void*)handle, str, maxStrSize);
-    if (realLength == -1)
+#ifdef HOST_UNIX
+    return nullptr;
+#else
+    char buff[512 + sizeof(CORINFO_String)];
+
+    // make this bulletproof, so it works even if we are wrong.
+    if (ReadProcessMemory(GetCurrentProcess(), (void*)strHandle, buff, 4, nullptr) == 0)
     {
-        printf("%s 'unknown frozen object'", prefix);
-        return;
+        return (nullptr);
     }
-    else if (realLength >= maxStrSize)
+
+    CORINFO_String* asString = nullptr;
+    if (impGetStringClass() == *((CORINFO_CLASS_HANDLE*)strHandle))
     {
-        // string is too long, trim it and null-terminate
-        str[maxStrSize - 4] = '.';
-        str[maxStrSize - 3] = '.';
-        str[maxStrSize - 2] = '.';
-        str[maxStrSize - 1] = 0;
+        // strHandle is a frozen string
+        // We assume strHandle is never an "interior" pointer in a frozen string
+        // (jit is not expected to perform such foldings)
+        asString = (CORINFO_String*)strHandle;
     }
     else
     {
-        // objectToString doesn't null-terminate buffer
-        str[realLength] = 0;
+        // strHandle is a pinned handle to a string object
+        asString = *((CORINFO_String**)strHandle);
     }
 
-    for (int i = 0; i < min(maxStrSize, realLength); i++)
+    if (ReadProcessMemory(GetCurrentProcess(), asString, buff, sizeof(buff), nullptr) == 0)
     {
-        // Replace \n and \r symbols with whitespaces
-        if (str[i] == '\n' || str[i] == '\r')
-        {
-            str[i] = ' ';
-        }
+        return (nullptr);
+    }
+
+    if (asString->stringLen >= 255 || asString->chars[asString->stringLen] != 0)
+    {
+        return nullptr;
     }
 
-    printf("%s '%s'\n", prefix, str);
+    return (WCHAR*)(asString->chars);
+#endif // HOST_UNIX
 }
 #else  // DEBUG
 void jitprintf(const char* fmt, ...)

src/coreclr/jit/emit.cpp

@@ -4129,15 +4129,42 @@ void emitter::emitDispCommentForHandle(size_t handle, size_t cookie, GenTreeFlag
 
     const char* str = nullptr;
     if (flag == GTF_ICON_STR_HDL)
-    {
-        str = "string handle";
-    }
-    else if (flag == GTF_ICON_OBJ_HDL)
     {
 #ifdef DEBUG
-        emitComp->eePrintFrozenObjectDescription(commentPrefix, handle);
+        const WCHAR* wstr = emitComp->eeGetCPString(handle);
+        // NOTE: eGetCPString always returns nullptr on Linux/ARM
+        if (wstr == nullptr)
+        {
+            str = "string handle";
+        }
+        else
+        {
+            const size_t actualLen = wcslen(wstr);
+            const size_t maxLength = 63;
+            const size_t newLen    = min(maxLength, actualLen);
+
+            // +1 for null terminator
+            WCHAR buf[maxLength + 1] = {0};
+            wcsncpy(buf, wstr, newLen);
+            for (size_t i = 0; i < newLen; i++)
+            {
+                // Escape \n and \r symbols
+                if (buf[i] == L'\n' || buf[i] == L'\r')
+                {
+                    buf[i] = L' ';
+                }
+            }
+            if (actualLen > maxLength)
+            {
+                // Append "..." for long strings
+                buf[maxLength - 3] = L'.';
+                buf[maxLength - 2] = L'.';
+                buf[maxLength - 1] = L'.';
+            }
+            printf("%s \"%S\"", commentPrefix, buf);
+        }
 #else
-        str                   = "frozen object handle";
+        str                   = "string handle";
 #endif
     }
     else if (flag == GTF_ICON_CLASS_HDL)

src/coreclr/jit/emitxarch.cpp

@@ -8756,6 +8756,18 @@ void emitter::emitDispAddrMode(instrDesc* id, bool noDetail)
 
     printf("]");
 
+// pretty print string if it looks like one
+#ifdef DEBUG
+    if ((id->idGCref() == GCT_GCREF) && (id->idIns() == INS_mov) && (id->idAddr()->iiaAddrMode.amBaseReg == REG_NA))
+    {
+        const WCHAR* str = emitComp->eeGetCPString(disp);
+        if (str != nullptr)
+        {
+            printf("      '%S'", str);
+        }
+    }
+#endif
+
     if (jdsc && !noDetail)
     {
         unsigned     cnt = (jdsc->dsSize - 1) / TARGET_POINTER_SIZE;

src/coreclr/jit/gcinfo.cpp

@@ -252,12 +252,6 @@ GCInfo::WriteBarrierForm GCInfo::gcIsWriteBarrierCandidate(GenTreeStoreInd* stor
         return WBF_NoBarrier;
     }
 
-    if (store->Data()->IsIconHandle(GTF_ICON_OBJ_HDL))
-    {
-        // Ignore frozen objects
-        return WBF_NoBarrier;
-    }
-
     WriteBarrierForm wbf = gcWriteBarrierFormFromTargetAddress(store->Addr());
 
     if (wbf == WBF_BarrierUnknown)