win64: add Julia personality

Author: vtjnash

src/codegen.cpp

@@ -3,13 +3,14 @@
 #include "llvm-version.h"
 #include "platform.h"
 #include "options.h"
-#if defined(_OS_WINDOWS_) && !defined(LLVM38)
-// trick pre-llvm38 into skipping the generation of _chkstk calls
+#if defined(_OS_WINDOWS_) && !defined(LLVM39)
+// trick pre-llvm39 into skipping the generation of _chkstk calls
 //   since it has some codegen issues associated with them:
 //   (a) assumed to be within 32-bit offset
 //   (b) bad asm is generated for certain code patterns:
 //       see https://github.com/JuliaLang/julia/pull/11644#issuecomment-112276813
 // also, use ELF because RuntimeDyld COFF I686 support didn't exist
+// also, use ELF because RuntimeDyld COFF X86_64 doesn't seem to work (fails to generate function pointers)?
 #define FORCE_ELF
 #endif
 #if defined(_CPU_X86_)
@@ -413,6 +414,9 @@ static Function *jlgetnthfieldchecked_func;
 //static Function *jlsetnthfield_func;
 #ifdef _OS_WINDOWS_
 static Function *resetstkoflw_func;
+#if defined(_CPU_X86_64_)
+static Function *juliapersonality_func;
+#endif
 #endif
 static Function *diff_gc_total_bytes_func;
 static Function *jlarray_data_owner_func;
@@ -5410,6 +5414,11 @@ static void init_julia_llvm_env(Module *m)
     resetstkoflw_func = Function::Create(FunctionType::get(T_int32, false),
             Function::ExternalLinkage, "_resetstkoflw", m);
     add_named_global(resetstkoflw_func, &_resetstkoflw);
+#if defined(_CPU_X86_64_)
+    juliapersonality_func = Function::Create(FunctionType::get(T_int32, true),
+            Function::ExternalLinkage, "__julia_personality", m);
+    add_named_global(juliapersonality_func, &__julia_personality);
+#endif
 #ifndef FORCE_ELF
 #if defined(_CPU_X86_64_)
 #if defined(_COMPILER_MINGW_)

src/debuginfo.cpp

@@ -128,9 +128,6 @@ void jl_add_linfo_in_flight(StringRef name, jl_lambda_info_t *linfo, const DataL
 }
 
 #if defined(_OS_WINDOWS_)
-#if defined(_CPU_X86_64_)
-extern "C" EXCEPTION_DISPOSITION _seh_exception_handler(PEXCEPTION_RECORD ExceptionRecord,void *EstablisherFrame, PCONTEXT ContextRecord, void *DispatcherContext);
-#endif
 static void create_PRUNTIME_FUNCTION(uint8_t *Code, size_t Size, StringRef fnname,
         uint8_t *Section, size_t Allocated, uint8_t *UnwindData)
 {
@@ -143,7 +140,7 @@ static void create_PRUNTIME_FUNCTION(uint8_t *Code, size_t Size, StringRef fnnam
     if (!catchjmp[0]) {
         catchjmp[0] = 0x48;
         catchjmp[1] = 0xb8; // mov RAX, QWORD PTR [...]
-        *(uint64_t*)(&catchjmp[2]) = (uint64_t)&_seh_exception_handler;
+        *(uint64_t*)(&catchjmp[2]) = (uint64_t)&__julia_personality;
         catchjmp[10] = 0xff;
         catchjmp[11] = 0xe0; // jmp RAX
         UnwindData[0] = 0x09; // version info, UNW_FLAG_EHANDLER
@@ -421,9 +418,9 @@ class JuliaJITEventListener: public JITEventListener
         assert(SectionAddrCheck);
         assert(SectionLoadOffset != 1);
         catchjmp[SectionLoadOffset] = 0x48;
-        catchjmp[SectionLoadOffset + 1] = 0xb8; // mov RAX, QWORD PTR [&_seh_exception_handle]
+        catchjmp[SectionLoadOffset + 1] = 0xb8; // mov RAX, QWORD PTR [&__julia_personality]
         *(uint64_t*)(&catchjmp[SectionLoadOffset + 2]) =
-            (uint64_t)&_seh_exception_handler;
+            (uint64_t)&__julia_personality;
         catchjmp[SectionLoadOffset + 10] = 0xff;
         catchjmp[SectionLoadOffset + 11] = 0xe0; // jmp RAX
         UnwindData[SectionLoadOffset] = 0x09; // version info, UNW_FLAG_EHANDLER

src/jitlayers.cpp

@@ -532,28 +532,35 @@ ExecutionEngine *jl_ExecutionEngine;
 #endif
 
 // MSVC's link.exe requires each function declaration to have a Comdat section
-// rather than litter the code with conditionals,
+// So rather than litter the code with conditionals,
 // all global values that get emitted call this function
 // and it decides whether the definition needs a Comdat section and adds the appropriate declaration
 // TODO: consider moving this into jl_add_to_shadow or jl_dump_shadow? the JIT doesn't care, so most calls are now no-ops
 template<class T> // for GlobalObject's
 static T *addComdat(T *G)
 {
-#if defined(_OS_WINDOWS_) && defined(_COMPILER_MICROSOFT_)
+#if defined(_OS_WINDOWS_) && defined(LLVM35)
     if (imaging_mode && !G->isDeclaration()) {
-#ifdef LLVM35
         // Add comdat information to make MSVC link.exe happy
+        // it's valid to emit this for ld.exe too,
+        // but makes it very slow to link for no benefit
+#if defined(_COMPILER_MICROSOFT_)
         if (G->getParent() == shadow_output) {
             Comdat *jl_Comdat = G->getParent()->getOrInsertComdat(G->getName());
             // ELF only supports Comdat::Any
             jl_Comdat->setSelectionKind(Comdat::NoDuplicates);
             G->setComdat(jl_Comdat);
         }
+#endif
         // add __declspec(dllexport) to everything marked for export
         if (G->getLinkage() == GlobalValue::ExternalLinkage)
             G->setDLLStorageClass(GlobalValue::DLLExportStorageClass);
         else
             G->setDLLStorageClass(GlobalValue::DefaultStorageClass);
+#if defined(_CPU_X86_64_)
+        // Add unwind exception personalities to functions to handle async exceptions
+        if (Function *F = dyn_cast<Function>(G))
+            F->setPersonalityFn(juliapersonality_func);
 #endif
     }
 #endif

src/julia_internal.h

@@ -343,6 +343,8 @@ typedef struct {
 uint64_t jl_getUnwindInfo(uint64_t dwBase);
 #ifdef _OS_WINDOWS_
 #include <dbghelp.h>
+JL_DLLEXPORT EXCEPTION_DISPOSITION __julia_personality(
+        PEXCEPTION_RECORD ExceptionRecord, void *EstablisherFrame, PCONTEXT ContextRecord, void *DispatcherContext);
 extern HANDLE hMainThread;
 typedef CONTEXT bt_context_t;
 #if defined(_CPU_X86_64_)

src/signals-win.c

@@ -278,8 +278,7 @@ static LONG WINAPI exception_handler(struct _EXCEPTION_POINTERS *ExceptionInfo)
 }
 
 #if defined(_CPU_X86_64_)
-EXCEPTION_DISPOSITION _seh_exception_handler(PEXCEPTION_RECORD ExceptionRecord, void *EstablisherFrame, PCONTEXT ContextRecord, void *DispatcherContext)
-{
+JL_DLLEXPORT EXCEPTION_DISPOSITION __julia_personality(PEXCEPTION_RECORD ExceptionRecord, void *EstablisherFrame, PCONTEXT ContextRecord, void *DispatcherContext) {
     EXCEPTION_POINTERS ExceptionInfo;
     ExceptionInfo.ExceptionRecord = ExceptionRecord;
     ExceptionInfo.ContextRecord = ContextRecord;