Reuse Darwin backtracing code for DRuntime_Use_Libunwind and use same…

… code path as libexec-based backtracing.

runtime/druntime/src/core/internal/backtrace/unwind.d

@@ -150,7 +150,7 @@ version (LDC) // simplify runtime function forward declaration
 else
     void _Unwind_Resume(_Unwind_Exception* exception_object);
 _Unwind_Reason_Code _Unwind_Resume_or_Rethrow(_Unwind_Exception* exception_object);
-_Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void*);
+_Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void*) nothrow;
 
 version (ARM_EABI_UNWINDER)
 {
@@ -160,46 +160,37 @@ version (ARM_EABI_UNWINDER)
     // On ARM, these are macros resp. not visible (static inline). To avoid
     // an unmaintainable amount of dependencies on implementation details,
     // just use a C shim (in ldc/arm_unwind.c).
-    _Unwind_Word _d_eh_GetGR(_Unwind_Context* context, int index);
+    _Unwind_Word _d_eh_GetGR(_Unwind_Context* context, int index) nothrow;
     alias _Unwind_GetGR = _d_eh_GetGR;
 
-    void _d_eh_SetGR(_Unwind_Context* context, int index, _Unwind_Word new_value);
+    void _d_eh_SetGR(_Unwind_Context* context, int index, _Unwind_Word new_value) nothrow;
     alias _Unwind_SetGR = _d_eh_SetGR;
 
-    _Unwind_Ptr _d_eh_GetIP(_Unwind_Context* context);
+    _Unwind_Ptr _d_eh_GetIP(_Unwind_Context* context) nothrow;
     alias _Unwind_GetIP = _d_eh_GetIP;
 
-    _Unwind_Ptr _d_eh_GetIPInfo(_Unwind_Context* context, int*);
+    _Unwind_Ptr _d_eh_GetIPInfo(_Unwind_Context* context, int*) nothrow;
     alias _Unwind_GetIPInfo = _d_eh_GetIPInfo;
 
-    void _d_eh_SetIP(_Unwind_Context* context, _Unwind_Ptr new_value);
+    void _d_eh_SetIP(_Unwind_Context* context, _Unwind_Ptr new_value) nothrow;
     alias _Unwind_SetIP = _d_eh_SetIP;
 }
 else
 {
-    _Unwind_Word _Unwind_GetGR(_Unwind_Context* context, int index);
-    void _Unwind_SetGR(_Unwind_Context* context, int index, _Unwind_Word new_value);
-    _Unwind_Ptr _Unwind_GetIP(_Unwind_Context* context);
-    _Unwind_Ptr _Unwind_GetIPInfo(_Unwind_Context* context, int*);
-    void _Unwind_SetIP(_Unwind_Context* context, _Unwind_Ptr new_value);
+    _Unwind_Word _Unwind_GetGR(_Unwind_Context* context, int index) nothrow;
+    void _Unwind_SetGR(_Unwind_Context* context, int index, _Unwind_Word new_value) nothrow;
+    _Unwind_Ptr _Unwind_GetIP(_Unwind_Context* context) nothrow;
+    _Unwind_Ptr _Unwind_GetIPInfo(_Unwind_Context* context, int*) nothrow;
+    void _Unwind_SetIP(_Unwind_Context* context, _Unwind_Ptr new_value) nothrow;
 }
-_Unwind_Word _Unwind_GetCFA(_Unwind_Context*);
-_Unwind_Word _Unwind_GetBSP(_Unwind_Context*);
-void* _Unwind_GetLanguageSpecificData(_Unwind_Context*);
-_Unwind_Ptr _Unwind_GetRegionStart(_Unwind_Context* context);
-void* _Unwind_FindEnclosingFunction(void* pc);
+_Unwind_Word _Unwind_GetCFA(_Unwind_Context*) nothrow;
+_Unwind_Word _Unwind_GetBSP(_Unwind_Context*) nothrow;
+void* _Unwind_GetLanguageSpecificData(_Unwind_Context*) nothrow;
+_Unwind_Ptr _Unwind_GetRegionStart(_Unwind_Context* context) nothrow;
+void* _Unwind_FindEnclosingFunction(void* pc) nothrow;
 
-version (X68_64)
+version (X86_64)
 {
-    _Unwind_Ptr _Unwind_GetDataRelBase(_Unwind_Context* context)
-    {
-        return _Unwind_GetGR(context, 1);
-    }
-
-    _Unwind_Ptr _Unwind_GetTextRelBase(_Unwind_Context* context)
-    {
-        assert(0);
-    }
 }
 else
 {

runtime/druntime/src/core/runtime.d

@@ -19,9 +19,17 @@ else version (TVOS)
 else version (WatchOS)
     version = Darwin;
 
+version(LDC) version (Darwin)
+{
+    // Use our own backtrace() based on _Unwind_Backtrace(), as the former (from
+    // execinfo) doesn't seem to handle missing frame pointers too well.
+    version = DefineBacktrace_using_UnwindBacktrace;
+}
+
 version (DRuntime_Use_Libunwind)
 {
-    import core.internal.backtrace.libunwind;
+    version = DefineBacktrace_using_UnwindBacktrace;
+
     // This shouldn't be necessary but ensure that code doesn't get mixed
     // It does however prevent the unittest SEGV handler to be installed,
     // which is desireable as it uses backtrace directly.
@@ -670,24 +678,11 @@ extern (C) UnitTestResult runModuleUnitTests()
     return results;
 }
 
-version (LDC) version (Darwin)
+version (DefineBacktrace_using_UnwindBacktrace)
 {
-    nothrow:
-
-    extern (C)
-    {
-        enum _URC_NO_REASON = 0;
-        enum _URC_END_OF_STACK = 5;
+    import core.internal.backtrace.unwind;
 
-        alias _Unwind_Context_Ptr = void*;
-        alias _Unwind_Trace_Fn = int function(_Unwind_Context_Ptr, void*);
-        int _Unwind_Backtrace(_Unwind_Trace_Fn, void*);
-        ptrdiff_t _Unwind_GetIP(_Unwind_Context_Ptr context);
-    }
-
-    // Use our own backtrce() based on _Unwind_Backtrace(), as the former (from
-    // execinfo) doesn't seem to handle missing frame pointers too well.
-    private int backtrace(void** buffer, int maxSize)
+    private int backtrace(void** buffer, int maxSize) nothrow
     {
         if (maxSize < 0) return 0;
 
@@ -698,7 +693,7 @@ version (LDC) version (Darwin)
             int entriesWritten = 0;
         }
 
-        static extern(C) int handler(_Unwind_Context_Ptr context, void* statePtr)
+        static extern(C) int handler(_Unwind_Context* context, void* statePtr)
         {
             auto state = cast(State*)statePtr;
             if (state.entriesWritten >= state.maxSize) return _URC_END_OF_STACK;
@@ -819,14 +814,8 @@ void defaultTraceDeallocator(Throwable.TraceInfo info) nothrow
     free(cast(void *)obj);
 }
 
-version (DRuntime_Use_Libunwind)
-{
-    import core.internal.backtrace.handler;
-
-    alias DefaultTraceInfo = LibunwindHandler;
-}
 /// Default implementation for most POSIX systems
-else version (Posix) private class DefaultTraceInfo : Throwable.TraceInfo
+version (Posix) private class DefaultTraceInfo : Throwable.TraceInfo
 {
     import core.demangle;
     import core.stdc.stdlib : free;