Add RtlVirtualUnwind back-end

CMakeLists.txt

@@ -142,6 +142,7 @@ target_sources(
     src/symbols/symbols_with_libdwarf.cpp
     src/symbols/symbols_with_nothing.cpp
     src/unwind/unwind_with_dbghelp.cpp
+    src/unwind/unwind_with_rtlvirtualunwind.cpp
     src/unwind/unwind_with_execinfo.cpp
     src/unwind/unwind_with_libunwind.cpp
     src/unwind/unwind_with_nothing.cpp
@@ -499,6 +500,10 @@ if(CPPTRACE_UNWIND_WITH_DBGHELP)
   target_link_libraries(${target_name} PRIVATE dbghelp)
 endif()
 
+if(CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND)
+  target_compile_definitions(${target_name} PRIVATE CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND)
+endif()
+
 if(CPPTRACE_UNWIND_WITH_NOTHING)
   target_compile_definitions(${target_name} PRIVATE CPPTRACE_UNWIND_WITH_NOTHING)
 endif()

ci/build-in-all-remaining-configs.py

@@ -17,6 +17,7 @@
     "CPPTRACE_UNWIND_WITH_EXECINFO",
     "CPPTRACE_UNWIND_WITH_WINAPI",
     "CPPTRACE_UNWIND_WITH_DBGHELP",
+    "CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND",
     "CPPTRACE_UNWIND_WITH_NOTHING",
 ]
 ALL_SYMBOL_OPTIONS = [

ci/test-all-configs.py

@@ -24,6 +24,7 @@ def get_c_compiler_counterpart(compiler: str) -> str:
     "CPPTRACE_UNWIND_WITH_EXECINFO",
     "CPPTRACE_UNWIND_WITH_WINAPI",
     "CPPTRACE_UNWIND_WITH_DBGHELP",
+    "CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND",
     "CPPTRACE_UNWIND_WITH_NOTHING",
 ]
 ALL_SYMBOL_OPTIONS = [
@@ -433,6 +434,7 @@ def run_windows_matrix(compilers: list, shared: bool):
             "unwind": [
                 "CPPTRACE_UNWIND_WITH_WINAPI",
                 "CPPTRACE_UNWIND_WITH_DBGHELP",
+                "CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND",
                 "CPPTRACE_UNWIND_WITH_UNWIND", # Broken on github actions for some reason
                 #"CPPTRACE_UNWIND_WITH_NOTHING",
             ],

cmake/Autoconfig.cmake

@@ -80,6 +80,7 @@ if(
     CPPTRACE_UNWIND_WITH_EXECINFO OR
     CPPTRACE_UNWIND_WITH_WINAPI OR
     CPPTRACE_UNWIND_WITH_DBGHELP OR
+    CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND OR
     CPPTRACE_UNWIND_WITH_NOTHING
   )
 )

cmake/OptionVariables.cmake

@@ -132,6 +132,7 @@ option(CPPTRACE_UNWIND_WITH_LIBUNWIND "" OFF)
 option(CPPTRACE_UNWIND_WITH_EXECINFO "" OFF)
 option(CPPTRACE_UNWIND_WITH_WINAPI "" OFF)
 option(CPPTRACE_UNWIND_WITH_DBGHELP "" OFF)
+option(CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND "" OFF)
 option(CPPTRACE_UNWIND_WITH_NOTHING "" OFF)
 
 # ---- Demangling Options ----

src/from_current.cpp

@@ -37,7 +37,7 @@ namespace detail {
         }
     }
 
-    #if defined(_MSC_VER) && defined(CPPTRACE_UNWIND_WITH_DBGHELP)
+    #if defined(_MSC_VER) && defined(CPPTRACE_UNWIND_WITH_EXCEPTION_POINTERS)
      CPPTRACE_FORCE_NO_INLINE void collect_current_trace(std::size_t skip, EXCEPTION_POINTERS* exception_ptrs) {
          try {
              #if defined(_M_IX86) || defined(__i386__)
@@ -376,7 +376,7 @@ CPPTRACE_BEGIN_NAMESPACE
         CPPTRACE_FORCE_NO_INLINE
         int maybe_collect_trace(EXCEPTION_POINTERS* exception_ptrs, int filter_result) {
             if(filter_result == EXCEPTION_EXECUTE_HANDLER) {
-                #ifdef CPPTRACE_UNWIND_WITH_DBGHELP
+                #ifdef CPPTRACE_UNWIND_WITH_EXCEPTION_POINTERS
                  collect_current_trace(1, exception_ptrs);
                 #else
                  collect_current_trace(1);
@@ -388,7 +388,7 @@ CPPTRACE_BEGIN_NAMESPACE
         CPPTRACE_FORCE_NO_INLINE
         void maybe_collect_trace(EXCEPTION_POINTERS* exception_ptrs, const std::type_info& type_info) {
             if(matches_exception(exception_ptrs, type_info)) {
-                #ifdef CPPTRACE_UNWIND_WITH_DBGHELP
+                #ifdef CPPTRACE_UNWIND_WITH_EXCEPTION_POINTERS
                  collect_current_trace(2, exception_ptrs);
                 #else
                  collect_current_trace(2);

src/unwind/unwind.hpp

@@ -6,7 +6,8 @@
 #include <cstddef>
 #include <vector>
 
-#ifdef CPPTRACE_UNWIND_WITH_DBGHELP
+#if defined(CPPTRACE_UNWIND_WITH_DBGHELP) || defined(CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND)
+ #define CPPTRACE_UNWIND_WITH_EXCEPTION_POINTERS
  #ifndef WIN32_LEAN_AND_MEAN
   #define WIN32_LEAN_AND_MEAN
  #endif
@@ -22,7 +23,7 @@ namespace detail {
     constexpr std::size_t hard_max_frames = 400;
     #endif
 
-    #ifdef CPPTRACE_UNWIND_WITH_DBGHELP
+    #ifdef CPPTRACE_UNWIND_WITH_EXCEPTION_POINTERS
      CPPTRACE_FORCE_NO_INLINE
      std::vector<frame_ptr> capture_frames(
          std::size_t skip,

src/unwind/unwind_with_rtlvirtualunwind.cpp

@@ -0,0 +1,105 @@
+#ifdef CPPTRACE_UNWIND_WITH_RTLVIRTUALUNWIND
+
+#include <cpptrace/basic.hpp>
+#include "unwind/unwind.hpp"
+#include "utils/common.hpp"
+#include "utils/utils.hpp"
+
+#include <cstddef>
+#include <vector>
+
+#ifndef WIN32_LEAN_AND_MEAN
+ #define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
+
+#if !defined(_M_X64) && !defined(__x86_64__) && !defined(_M_ARM64) && !defined(__aarch64__)
+ #error "Cpptrace: RtlVirtualUnwind is only supported on 64-bit Windows"
+#endif
+
+namespace {
+DWORD64 context_pc(CONTEXT& context) {
+    #if defined(_M_X64) || defined(__x86_64__)
+     return context.Rip;
+    #elif defined(_M_ARM64) || defined(__aarch64__)
+     return context.Pc;
+    #endif
+}
+}
+
+CPPTRACE_BEGIN_NAMESPACE
+namespace detail {
+    CPPTRACE_FORCE_NO_INLINE
+    std::vector<frame_ptr> capture_frames(
+        std::size_t skip,
+        std::size_t max_depth,
+        EXCEPTION_POINTERS* exception_pointers
+    ) {
+        CONTEXT context;
+        ZeroMemory(&context, sizeof(CONTEXT));
+        if(exception_pointers) {
+            context = *exception_pointers->ContextRecord;
+        } else {
+            skip++; // we're unwinding from the capture_frames frame, skip it
+            RtlCaptureContext(&context);
+        }
+
+        std::vector<frame_ptr> trace;
+        while(trace.size() < max_depth) {
+            DWORD64 image_base;
+            PRUNTIME_FUNCTION function_entry = RtlLookupFunctionEntry(context_pc(context), &image_base, NULL);
+            if(!function_entry) {
+                break;
+            }
+            if(skip) {
+                skip--;
+            } else {
+                // Same adjustment as StackWalk64
+                trace.push_back(to_frame_ptr(context_pc(context)) - 1);
+            }
+            #if defined(_M_X64) || defined(__x86_64__)
+            PVOID handler_data;
+            DWORD64 establisher_frame;
+            RtlVirtualUnwind(
+                UNW_FLAG_NHANDLER,
+                image_base,
+                context_pc(context),
+                function_entry,
+                &context,
+                &handler_data,
+                &establisher_frame,
+                NULL
+            );
+            #elif defined(_M_ARM64) || defined(__aarch64__)
+            BOOLEAN in_function;
+            FRAME_POINTERS establisher_frame;
+            RtlVirtualUnwind(
+                image_base,
+                context_pc(context),
+                function_entry,
+                &context,
+                &in_function,
+                &establisher_frame,
+                NULL
+            );
+            #endif
+            if(context_pc(context) == 0) {
+                break;
+            }
+        }
+        return trace;
+    }
+
+    CPPTRACE_FORCE_NO_INLINE
+    std::size_t safe_capture_frames(frame_ptr*, std::size_t, std::size_t, std::size_t) {
+        // Can't safe trace with RtlVirtualUnwind
+        return 0;
+    }
+
+    bool has_safe_unwind() {
+        return false;
+    }
+}
+CPPTRACE_END_NAMESPACE
+
+#endif