Merge pull request #11667 from JuliaLang/kf/unwinder

Register JIT frames with the correct unwinder when linking LLVM dylib

src/Makefile

@@ -28,6 +28,7 @@ endif
 LLVMLINK = $(call exec,$(LLVM_CONFIG) --ldflags) $(call exec,$(LLVM_CONFIG) --libs) $(call exec,$(LLVM_CONFIG) --ldflags) $(call exec,$(LLVM_CONFIG) --system-libs 2> /dev/null)
 ifeq ($(USE_LLVM_SHLIB),1)
 LLVMLINK = $(call exec,$(LLVM_CONFIG) --ldflags) -lLLVM-$(call exec,$(LLVM_CONFIG) --version)
+FLAGS += -DLLVM_SHLIB
 endif
 
 COMMON_LIBS = -L$(build_shlibdir) -L$(build_libdir) $(LIBUV) $(LIBUTF8PROC) $(NO_WHOLE_ARCHIVE) $(LLVMLINK) $(OSLIBS)

src/codegen.cpp

@@ -269,6 +269,10 @@ static GlobalVariable *jldll_var;
 extern JITMemoryManager* createJITMemoryManagerWin();
 #endif
 #endif //_OS_WINDOWS_
+#if defined(_OS_DARWIN_) && defined(LLVM37) && defined(LLVM_SHLIB)
+#define CUSTOM_MEMORY_MANAGER 1
+extern RTDyldMemoryManager* createRTDyldMemoryManagerOSX();
+#endif
 
 // important functions
 static Function *jlnew_func;
@@ -5623,6 +5627,8 @@ extern "C" void jl_init_codegen(void)
  eb .setEngineKind(EngineKind::JIT)
 #if defined(_OS_WINDOWS_) && defined(_CPU_X86_64_) && !defined(USE_MCJIT)
  .setJITMemoryManager(createJITMemoryManagerWin())
+#elif defined(CUSTOM_MEMORY_MANAGER)
+ .setMCJITMemoryManager(std::move(std::unique_ptr<RTDyldMemoryManager>{createRTDyldMemoryManagerOSX()}))
 #endif
  .setTargetOptions(options)
  .setRelocationModel(Reloc::PIC_)

src/debuginfo.cpp

@@ -842,6 +842,77 @@ int jl_get_llvmf_info(uint64_t fptr, uint64_t *symsize, uint64_t *slide,
 }
 
 
+#if defined(_OS_DARWIN_) && defined(LLVM37) && defined(LLVM_SHLIB)
+
+/*
+ * We use a custom unwinder, so we need to make sure that when registering dynamic
+ * frames, we do so with our unwinder rather than with the system one. If LLVM is
+ * statically linked everything works out fine, but if it's dynamically linked
+ * it would usually pick up the system one, so we need to do the registration
+ * ourselves to ensure the right one gets picked.
+ */
+
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
+class RTDyldMemoryManagerOSX : public SectionMemoryManager
+{
+ RTDyldMemoryManagerOSX(const RTDyldMemoryManagerOSX&) = delete;
+ void operator=(const RTDyldMemoryManagerOSX&) = delete;
+
+public:
+ RTDyldMemoryManagerOSX() {};
+ ~RTDyldMemoryManagerOSX() override {};
+ void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override;
+ void deregisterEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size);
+};
+
+extern "C" void __register_frame(void*);
+extern "C" void __deregister_frame(void*);
+
+static const char *processFDE(const char *Entry, bool isDeregister) {
+ const char *P = Entry;
+ uint32_t Length = *((const uint32_t *)P);
+ P += 4;
+ uint32_t Offset = *((const uint32_t *)P);
+ if (Offset != 0) {
+ if (isDeregister)
+ __deregister_frame(const_cast<char *>(Entry));
+ else
+ __register_frame(const_cast<char *>(Entry));
+ }
+ return P + Length;
+}
+
+// This implementation handles frame registration for local targets.
+// Memory managers for remote targets should re-implement this function
+// and use the LoadAddr parameter.
+void RTDyldMemoryManagerOSX::registerEHFrames(uint8_t *Addr,
+ uint64_t LoadAddr,
+ size_t Size) {
+ // On OS X OS X __register_frame takes a single FDE as an argument.
+ // See http:https://lists.cs.uiuc.edu/pipermail/llvmdev/2013-April/061768.html
+ const char *P = (const char *)Addr;
+ const char *End = P + Size;
+ do {
+ P = processFDE(P, false);
+ } while(P != End);
+}
+
+void RTDyldMemoryManagerOSX::deregisterEHFrames(uint8_t *Addr,
+ uint64_t LoadAddr,
+ size_t Size) {
+ const char *P = (const char *)Addr;
+ const char *End = P + Size;
+ do {
+ P = processFDE(P, true);
+ } while(P != End);
+}
+
+RTDyldMemoryManager* createRTDyldMemoryManagerOSX() {
+ return new RTDyldMemoryManagerOSX();
+}
+
+#endif
+
 #if defined(_OS_WINDOWS_)
 #ifdef USE_MCJIT
 extern "C"