Unhandled exception handling on Unix (#2157)

jkotas · web-flow · commit cb9c8599b93f · 2016-11-07T09:41:42.000-08:00
- Reduced differences between the unwind info, gc info and eh info encodings between Windows and Unix.
- Miscellaneous tweaks to get unhandled exceptions fail with gracefully with error message and abort with this change
diff --git a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ObjectWriter.cs b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ObjectWriter.cs
@@ -356,17 +356,18 @@ public void BuildCFIMap(NodeFactory factory, ObjectNode node)
             ObjectNode.ObjectData ehInfo = nodeWithCodeInfo.EHInfo;
             string mainEhInfoSymbolName = null;
 
-            int i = 0;
-            foreach (var frameInfo in frameInfos)
+            for (int i = 0; i < frameInfos.Length; i++)
             {
+                FrameInfo frameInfo = frameInfos[i];
+
                 int start = frameInfo.StartOffset;
                 int end = frameInfo.EndOffset;
                 int len = frameInfo.BlobData.Length;
                 byte[] blob = frameInfo.BlobData;
 
                 if (_targetPlatform.OperatingSystem == TargetOS.Windows)
                 {
-                    string blobSymbolName = "_unwind" + (i++).ToStringInvariant() + _currentNodeName;
+                    string blobSymbolName = "_unwind" + i.ToStringInvariant() + _currentNodeName;
 
                     ObjectNodeSection section = ObjectNodeSection.XDataSection;
                     if (node.ShouldShareNodeAcrossModules(factory) && factory.Target.OperatingSystem == TargetOS.Windows)
@@ -421,37 +422,48 @@ public void BuildCFIMap(NodeFactory factory, ObjectNode node)
                 }
                 else
                 {
-                    string blobSymbolName = "_lsda" + (i++).ToStringInvariant() + _currentNodeName;
+                    string blobSymbolName = "_lsda" + i.ToStringInvariant() + _currentNodeName;
 
                     SwitchSection(_nativeObjectWriter, LsdaSection.Name);
 
-                    EmitAlignment(4);
                     EmitSymbolDef(blobSymbolName);
 
-                    // emit relative offset from the main function
-                    EmitIntValue((ulong)(start - frameInfos[0].StartOffset), 4);
-
-                    // emit last byte from the blob - the function kind
                     FrameInfoFlags flags = frameInfo.Flags;
-                    if ((ehInfo != null) || (mainEhInfoSymbolName != null))
+                    if (ehInfo != null)
                     {
                         flags |= FrameInfoFlags.HasEHInfo;
                     }
                     EmitIntValue((byte)flags, 1);
 
+                    if (i != 0)
+                    {
+                        EmitSymbolRef("_lsda0" + _currentNodeName, RelocType.IMAGE_REL_BASED_REL32, 4);
+
+                        // emit relative offset from the main function
+                        EmitIntValue((ulong)(start - frameInfos[0].StartOffset), 4);
+                    }
+
+                    if (ehInfo != null)
+                    {
+                        mainEhInfoSymbolName = "_ehInfo" + _currentNodeName;
+                        EmitSymbolRef(mainEhInfoSymbolName, RelocType.IMAGE_REL_BASED_REL32, 4);
+                    }
+
+                    if (gcInfo != null)
+                    {
+                        EmitBlob(gcInfo);
+                        gcInfo = null;
+                    }
+
                     if (ehInfo != null)
                     {
+                        // TODO: Place EHInfo into different section for better locality
                         Debug.Assert(ehInfo.Alignment == 1);
                         Debug.Assert(ehInfo.DefinedSymbols.Length == 0);
-                        mainEhInfoSymbolName = "_ehInfo" + _currentNodeName;
                         EmitSymbolDef(mainEhInfoSymbolName);
                         EmitBlobWithRelocs(ehInfo.Data, ehInfo.Relocs);
                         ehInfo = null;
                     }
-                    else if (mainEhInfoSymbolName != null)
-                    {
-                        EmitSymbolRef(mainEhInfoSymbolName, RelocType.IMAGE_REL_BASED_REL32, 4);
-                    }
 
                     // For Unix, we build CFI blob map for each offset.
                     Debug.Assert(len % CfiCodeSize == 0);
diff --git a/src/Native/Bootstrap/platform.unix.cpp b/src/Native/Bootstrap/platform.unix.cpp
@@ -68,12 +68,11 @@ extern "C"
 
     void OutputDebugStringW()
     {
-        throw "OutputDebugStringW";
     }
 
     uint32_t GetCurrentThreadId()
     {
-        throw "GetCurrentThreadId";
+        return 42;
     }
 
     uint32_t RhCompatibleReentrantWaitAny(uint32_t alertable, uint32_t timeout, uint32_t count, void* pHandles)
diff --git a/src/Native/Runtime/unix/UnixContext.cpp b/src/Native/Runtime/unix/UnixContext.cpp
@@ -403,6 +403,10 @@ void UnwindCursorToRegDisplay(unw_cursor_t *cursor, unw_context_t *unwContext, R
     unw_get_reg(cursor, UNW_REG_IP, (unw_word_t *) &regDisplay->IP);
     unw_get_reg(cursor, UNW_REG_SP, (unw_word_t *) &regDisplay->SP);
 
+#if defined(_AMD64_)
+    regDisplay->pIP = PTR_PCODE(regDisplay->SP - sizeof(TADDR));
+#endif
+
 #if defined(_ARM_) || defined(_ARM64_)
     regDisplay->IP |= 1;
 #endif
diff --git a/src/Native/Runtime/unix/UnixNativeCodeManager.cpp b/src/Native/Runtime/unix/UnixNativeCodeManager.cpp
@@ -14,6 +14,9 @@
 
 #include "CommonMacros.inl"
 
+#define GCINFODECODER_NO_EE
+#include "coreclr/gcinfodecoder.cpp"
+
 #include "UnixContext.h"
 
 #define UBF_FUNC_KIND_MASK      0x03
@@ -23,11 +26,13 @@
 
 #define UBF_FUNC_HAS_EHINFO     0x04
 
+#define UBF_FUNC_REVERSE_PINVOKE 0x08
+
 struct UnixNativeMethodInfo
 {
     PTR_VOID pMethodStartAddress;
-    PTR_UInt8 pEhInfo;
-    uint8_t funcFlags;
+    PTR_UInt8 pMainLSDA;
+    PTR_UInt8 pLSDA;
     bool executionAborted;
 };
 
@@ -57,30 +62,26 @@ bool UnixNativeCodeManager::FindMethodInfo(PTR_VOID        ControlPC,
         return false;
     }
 
-    PTR_UInt8 lsdaPtr = dac_cast<PTR_UInt8>(lsda);
+    PTR_UInt8 p = dac_cast<PTR_UInt8>(lsda);
 
-    int offsetFromMainFunction = *dac_cast<PTR_Int32>(lsdaPtr);
-    lsdaPtr += sizeof(int);
-    pMethodInfo->funcFlags = *lsdaPtr;
-    ++lsdaPtr;
+    pMethodInfo->pLSDA = p;
 
-    PTR_UInt8 ehInfoPtr = NULL;
-    if (pMethodInfo->funcFlags & UBF_FUNC_HAS_EHINFO)
+    uint8_t unwindBlockFlags = *p++;
+
+    if ((unwindBlockFlags & UBF_FUNC_KIND_MASK) != UBF_FUNC_KIND_ROOT)
     {
-        // main function contains the EH info blob in its LSDA, funclets just refer
-        // to the main function's blob
-        if (offsetFromMainFunction == 0)
-        {
-            ehInfoPtr = lsdaPtr;
-        }
-        else
-        {
-            ehInfoPtr = lsdaPtr + *dac_cast<PTR_Int32>(lsdaPtr);
-        }
+        // Funclets just refer to the main function's blob
+        pMethodInfo->pMainLSDA = p + *dac_cast<PTR_Int32>(p);
+        p += sizeof(int32_t);
+
+        pMethodInfo->pMethodStartAddress = dac_cast<PTR_VOID>(startAddress - *dac_cast<PTR_Int32>(p));
+    }
+    else
+    {
+        pMethodInfo->pMainLSDA = dac_cast<PTR_UInt8>(lsda);
+        pMethodInfo->pMethodStartAddress = dac_cast<PTR_VOID>(startAddress);
     }
 
-    pMethodInfo->pMethodStartAddress = (PTR_VOID)(startAddress - offsetFromMainFunction);
-    pMethodInfo->pEhInfo = ehInfoPtr;
     pMethodInfo->executionAborted = false;
 
     return true;
@@ -90,7 +91,8 @@ bool UnixNativeCodeManager::IsFunclet(MethodInfo * pMethodInfo)
 {
     UnixNativeMethodInfo * pNativeMethodInfo = (UnixNativeMethodInfo *)pMethodInfo;
 
-    return (pNativeMethodInfo->funcFlags & UBF_FUNC_KIND_MASK) != UBF_FUNC_KIND_ROOT;
+    uint8_t unwindBlockFlags = *(pNativeMethodInfo->pLSDA);
+    return (unwindBlockFlags & UBF_FUNC_KIND_MASK) != UBF_FUNC_KIND_ROOT;
 }
 
 PTR_VOID UnixNativeCodeManager::GetFramePointer(MethodInfo *   pMethodInfo,
@@ -99,7 +101,7 @@ PTR_VOID UnixNativeCodeManager::GetFramePointer(MethodInfo *   pMethodInfo,
     UnixNativeMethodInfo * pNativeMethodInfo = (UnixNativeMethodInfo *)pMethodInfo;
 
     // Return frame pointer for methods with EH and funclets
-    uint8_t unwindBlockFlags = pNativeMethodInfo->funcFlags;
+    uint8_t unwindBlockFlags = *(pNativeMethodInfo->pLSDA);
     if ((unwindBlockFlags & UBF_FUNC_HAS_EHINFO) != 0 || (unwindBlockFlags & UBF_FUNC_KIND_MASK) != UBF_FUNC_KIND_ROOT)
     {
         return (PTR_VOID)pRegisterSet->GetFP();
@@ -127,14 +129,37 @@ bool UnixNativeCodeManager::UnwindStackFrame(MethodInfo *    pMethodInfo,
                                              REGDISPLAY *    pRegisterSet,                 // in/out
                                              PTR_VOID *      ppPreviousTransitionFrame)    // out
 {
-    if (!VirtualUnwind(pRegisterSet))
+    UnixNativeMethodInfo * pNativeMethodInfo = (UnixNativeMethodInfo *)pMethodInfo;
+
+    PTR_UInt8 p = pNativeMethodInfo->pMainLSDA;
+
+    uint8_t unwindBlockFlags = *p++;
+
+    if ((unwindBlockFlags & UBF_FUNC_REVERSE_PINVOKE) != 0)
     {
-        return false;
+        // Reverse PInvoke transition should on the main function body only
+        assert(pNativeMethodInfo->pMainLSDA == pNativeMethodInfo->pLSDA);
+
+        if ((unwindBlockFlags & UBF_FUNC_HAS_EHINFO) != 0)
+            p += sizeof(int32_t);
+
+        GcInfoDecoder decoder(GCInfoToken(p), DECODE_REVERSE_PINVOKE_VAR);
+
+        // @TODO: CORERT: Encode reverse PInvoke frame slot in GCInfo: https://github.com/dotnet/corert/issues/2115
+        // INT32 slot = decoder.GetReversePInvokeFrameStackSlot();
+        // assert(slot != NO_REVERSE_PINVOKE_FRAME);
+
+        *ppPreviousTransitionFrame = (PTR_VOID)-1;
+        return true;
     }
 
-    // @TODO: CORERT: PInvoke transitions
     *ppPreviousTransitionFrame = NULL;
 
+    if (!VirtualUnwind(pRegisterSet))
+    {
+        return false;
+    }
+
     return true;
 }
 
@@ -187,8 +212,12 @@ bool UnixNativeCodeManager::EHEnumInit(MethodInfo * pMethodInfo, PTR_VOID * pMet
 
     UnixNativeMethodInfo * pNativeMethodInfo = (UnixNativeMethodInfo *)pMethodInfo;
 
+    PTR_UInt8 p = pNativeMethodInfo->pMainLSDA;
+
+    uint8_t unwindBlockFlags = *p++;
+
     // return if there is no EH info associated with this method
-    if ((pNativeMethodInfo->funcFlags & UBF_FUNC_HAS_EHINFO) == 0)
+    if ((unwindBlockFlags & UBF_FUNC_HAS_EHINFO) == 0)
     {
         return false;
     }
@@ -198,7 +227,7 @@ bool UnixNativeCodeManager::EHEnumInit(MethodInfo * pMethodInfo, PTR_VOID * pMet
     *pMethodStartAddress = pNativeMethodInfo->pMethodStartAddress;
 
     pEnumState->pMethodStartAddress = dac_cast<PTR_UInt8>(pNativeMethodInfo->pMethodStartAddress);
-    pEnumState->pEHInfo = pNativeMethodInfo->pEhInfo;
+    pEnumState->pEHInfo = dac_cast<PTR_UInt8>(p + *dac_cast<PTR_Int32>(p));
     pEnumState->uClause = 0;
     pEnumState->nClauses = VarInt::ReadUnsigned(pEnumState->pEHInfo);
 
diff --git a/src/Native/Runtime/windows/CoffNativeCodeManager.cpp b/src/Native/Runtime/windows/CoffNativeCodeManager.cpp
@@ -17,7 +17,7 @@
 #include "CommonMacros.inl"
 
 #define GCINFODECODER_NO_EE
-#include "coreclr\gcinfodecoder.cpp"
+#include "coreclr/gcinfodecoder.cpp"
 
 #define UBF_FUNC_KIND_MASK      0x03
 #define UBF_FUNC_KIND_ROOT      0x00
@@ -306,27 +306,32 @@ bool CoffNativeCodeManager::UnwindStackFrame(MethodInfo *    pMethodInfo,
     CoffNativeMethodInfo * pNativeMethodInfo = (CoffNativeMethodInfo *)pMethodInfo;
 
     size_t unwindDataBlobSize;
-    PTR_VOID pUnwindDataBlob = GetUnwindDataBlob(m_moduleBase, pNativeMethodInfo->mainRuntimeFunction, &unwindDataBlobSize);
+    PTR_VOID pUnwindDataBlob = GetUnwindDataBlob(m_moduleBase, pNativeMethodInfo->runtimeFunction, &unwindDataBlobSize);
 
     PTR_UInt8 p = dac_cast<PTR_UInt8>(pUnwindDataBlob) + unwindDataBlobSize;
 
     uint8_t unwindBlockFlags = *p++;
 
     if ((unwindBlockFlags & UBF_FUNC_REVERSE_PINVOKE) != 0)
     {
+        // Reverse PInvoke transition should on the main function body only
+        assert(pNativeMethodInfo->mainRuntimeFunction == pNativeMethodInfo->runtimeFunction);
+
+        if ((unwindBlockFlags & UBF_FUNC_HAS_EHINFO) != 0)
+            p += sizeof(int32_t);
+
         GcInfoDecoder decoder(GCInfoToken(p), DECODE_REVERSE_PINVOKE_VAR);
 
         // @TODO: CORERT: Encode reverse PInvoke frame slot in GCInfo: https://github.com/dotnet/corert/issues/2115
         // INT32 slot = decoder.GetReversePInvokeFrameStackSlot();
         // assert(slot != NO_REVERSE_PINVOKE_FRAME);
 
         *ppPreviousTransitionFrame = (PTR_VOID)-1;
-    }
-    else
-    {
-        *ppPreviousTransitionFrame = NULL;
+        return true;
     }
 
+    *ppPreviousTransitionFrame = NULL;
+
     CONTEXT context;
     KNONVOLATILE_CONTEXT_POINTERS contextPointers;
 
@@ -444,6 +449,7 @@ bool CoffNativeCodeManager::EHEnumInit(MethodInfo * pMethodInfo, PTR_VOID * pMet
     }
 
     *pMethodStartAddress = dac_cast<PTR_VOID>(m_moduleBase + pNativeMethodInfo->mainRuntimeFunction->BeginAddress);
+
     pEnumState->pMethodStartAddress = dac_cast<PTR_UInt8>(*pMethodStartAddress);
     pEnumState->pEHInfo = dac_cast<PTR_UInt8>(m_moduleBase + *dac_cast<PTR_Int32>(p));
     pEnumState->uClause = 0;

Original file line number	Diff line number	Diff line change
`@@ -68,12 +68,11 @@ extern "C"`
`68`	`68`
`69`	`69`	`void OutputDebugStringW()`
`70`	`70`	`{`
`71`		`- throw "OutputDebugStringW";`
`72`	`71`	`}`
`73`	`72`
`74`	`73`	`uint32_t GetCurrentThreadId()`
`75`	`74`	`{`
`76`		`- throw "GetCurrentThreadId";`
	`75`	`+ return 42;`
`77`	`76`	`}`
`78`	`77`
`79`	`78`	`uint32_t RhCompatibleReentrantWaitAny(uint32_t alertable, uint32_t timeout, uint32_t count, void* pHandles)`