Test and fix 32-bit windows (#262)

jeremy-rifkin · web-flow · commit 95e98c7f5755 · 2025-06-16T13:48:10.000-05:00
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -678,6 +678,28 @@ jobs:
            ninja
            ./unittest_module
 
+  unittest-windows-32-bit:
+    runs-on: windows-2022
+    needs: unittest-windows
+    strategy:
+      fail-fast: false
+      matrix:
+        build_type: [Debug]
+    steps:
+    - uses: actions/checkout@v4
+    - name: Enable Developer Command Prompt
+      uses: ilammy/msvc-dev-cmd@v1.13.0
+    - name: build and test
+      run: |
+           mkdir build
+           cd build
+           cmake .. `
+            -A Win32 `
+            -DCPPTRACE_WERROR_BUILD=On `
+            -DCPPTRACE_BUILD_TESTING=On
+           cmake --build . --config ${{matrix.build_type}}
+           ./${{matrix.build_type}}/unittest
+
   unittest-windows-clangcl:
     runs-on: windows-2022
     needs: unittest-windows
diff --git a/include/cpptrace/from_current.hpp b/include/cpptrace/from_current.hpp
@@ -41,23 +41,21 @@ CPPTRACE_BEGIN_NAMESPACE
             using type = void;
         };
 
-        CPPTRACE_EXPORT CPPTRACE_FORCE_NO_INLINE void collect_current_trace(std::size_t skip);
-
         #ifdef _MSC_VER
-         CPPTRACE_EXPORT bool matches_exception(EXCEPTION_POINTERS* exception_ptrs, const std::type_info& type_info);
+         CPPTRACE_EXPORT CPPTRACE_FORCE_NO_INLINE
+         void maybe_collect_trace(EXCEPTION_POINTERS* exception_ptrs, const std::type_info& type_info);
          template<typename E>
          CPPTRACE_FORCE_NO_INLINE inline int exception_filter(EXCEPTION_POINTERS* exception_ptrs) {
-             if(matches_exception(exception_ptrs, typeid(E))) {
-                 collect_current_trace(1);
-             }
+             maybe_collect_trace(exception_ptrs, typeid(E));
              return EXCEPTION_CONTINUE_SEARCH;
          }
          class dont_return_from_try_catch_macros {
          public:
              explicit dont_return_from_try_catch_macros() = default;
          };
         #else
-         CPPTRACE_EXPORT bool check_can_catch(const std::type_info*, const std::type_info*, void**, unsigned);
+         CPPTRACE_EXPORT CPPTRACE_FORCE_NO_INLINE
+         void maybe_collect_trace(const std::type_info*, const std::type_info*, void**, unsigned);
          template<typename T>
          class unwind_interceptor {
          public:
@@ -68,9 +66,7 @@ CPPTRACE_BEGIN_NAMESPACE
                  void** throw_obj,
                  unsigned outer
              ) {
-                 if(check_can_catch(&typeid(T), throw_type, throw_obj, outer)) {
-                     collect_current_trace(1);
-                 }
+                 maybe_collect_trace(&typeid(T), throw_type, throw_obj, outer);
                  return false;
              }
          };
diff --git a/src/from_current.cpp b/src/from_current.cpp
@@ -11,6 +11,7 @@
 #include "utils/microfmt.hpp"
 #include "utils/utils.hpp"
 #include "logging.hpp"
+#include "unwind/unwind.hpp"
 
 #ifndef _MSC_VER
  #include <string.h>
@@ -44,8 +45,7 @@ namespace detail {
         return rethrow_switch;
     }
 
-    CPPTRACE_FORCE_NO_INLINE void collect_current_trace(std::size_t skip) {
-        auto trace = cpptrace::generate_raw_trace(skip + 1);
+    void save_current_trace(raw_trace trace) {
         if(get_rethrow_switch()) {
             saved_rethrow_trace = lazy_trace_holder(std::move(trace));
         } else {
@@ -54,6 +54,33 @@ namespace detail {
         }
     }
 
+    #if defined(_MSC_VER) && defined(CPPTRACE_UNWIND_WITH_DBGHELP)
+     CPPTRACE_FORCE_NO_INLINE void collect_current_trace(std::size_t skip, EXCEPTION_POINTERS* exception_ptrs) {
+         try {
+             #if defined(_M_IX86) || defined(__i386__)
+              // skip one frame, first is CxxThrowException
+              (void)skip;
+              auto trace = raw_trace{detail::capture_frames(1, SIZE_MAX, exception_ptrs)};
+             #else
+              (void)exception_ptrs;
+              auto trace = raw_trace{detail::capture_frames(skip + 1, SIZE_MAX)};
+             #endif
+             save_current_trace(std::move(trace));
+         } catch(...) {
+             detail::log_and_maybe_propagate_exception(std::current_exception());
+         }
+     }
+    #else
+     CPPTRACE_FORCE_NO_INLINE void collect_current_trace(std::size_t skip) {
+         try {
+             auto trace = raw_trace{detail::capture_frames(skip + 1, SIZE_MAX)};
+             save_current_trace(std::move(trace));
+         } catch(...) {
+             detail::log_and_maybe_propagate_exception(std::current_exception());
+         }
+     }
+    #endif
+
     #ifdef _MSC_VER
     // https://www.youtube.com/watch?v=COEv2kq_Ht8
     // https://github.com/tpn/pdfs/blob/master/2018%20CppCon%20Unwinding%20the%20Stack%20-%20Exploring%20how%20C%2B%2B%20Exceptions%20work%20on%20Windows%20-%20James%20McNellis.pdf
@@ -66,7 +93,7 @@ namespace detail {
     // - https://github.com/ecatmur/stacktrace-from-exception/blob/main/stacktrace-from-exception.cpp
     // - https://github.com/catboost/catboost/blob/master/contrib/libs/cxxsupp/libcxx/src/support/runtime/exception_pointer_msvc.ipp
     // - https://www.geoffchappell.com/studies/msvc/language/predefined/index.htm
-    #if defined _WIN64
+    #ifdef _WIN64
      #pragma pack(push, 4)
      struct CatchableType {
          std::uint32_t properties;
@@ -85,19 +112,20 @@ namespace detail {
      };
      #pragma warning(disable:4200)
      #if IS_CLANG
-     #pragma clang diagnostic push
-     #pragma clang diagnostic ignored "-Wc99-extensions"
+      #pragma clang diagnostic push
+      #pragma clang diagnostic ignored "-Wc99-extensions"
      #endif
      struct CatchableTypeArray {
          uint32_t nCatchableTypes;
          int32_t arrayOfCatchableTypes[];
      };
      #if IS_CLANG
-     #pragma clang diagnostic pop
+      #pragma clang diagnostic pop
      #endif
      #pragma warning (pop)
      #pragma pack(pop)
     #else
+     using CatchableTypeArray = ::_CatchableTypeArray;
      using CatchableType = ::_CatchableType;
      using ThrowInfo = ::_ThrowInfo;
     #endif
@@ -583,14 +611,27 @@ CPPTRACE_BEGIN_NAMESPACE
             CPPTRACE_POP_EXTENSION_WARNINGS
             return false;
         }
+        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
+                collect_current_trace(2, exception_ptrs);
+                #else
+                collect_current_trace(2);
+                #endif
+            }
+        }
         #else
-        bool check_can_catch(
+        CPPTRACE_FORCE_NO_INLINE
+        void maybe_collect_trace(
             const std::type_info* type,
             const std::type_info* throw_type,
             void** throw_obj,
             unsigned outer
         ) {
-            return detail::can_catch(type, throw_type, throw_obj, outer);
+            if(detail::can_catch(type, throw_type, throw_obj, outer)) {
+                collect_current_trace(2);
+            }
         }
 
         void do_prepare_unwind_interceptor(const std::type_info& type_info, bool(*can_catch)(const std::type_info*, const std::type_info*, void**, unsigned)) {
diff --git a/src/unwind/unwind.hpp b/src/unwind/unwind.hpp
@@ -6,6 +6,13 @@
 #include <cstddef>
 #include <vector>
 
+#ifdef CPPTRACE_UNWIND_WITH_DBGHELP
+ #define UNWIND_MAY_NEED_CONTEXT_RECORD
+ #define WIN32_LEAN_AND_MEAN
+ #include <windows.h>
+#endif
+
+
 CPPTRACE_BEGIN_NAMESPACE
 namespace detail {
     #ifdef CPPTRACE_HARD_MAX_FRAMES
@@ -14,8 +21,17 @@ namespace detail {
     constexpr std::size_t hard_max_frames = 400;
     #endif
 
-    CPPTRACE_FORCE_NO_INLINE
-    std::vector<frame_ptr> capture_frames(std::size_t skip, std::size_t max_depth);
+    #ifdef CPPTRACE_UNWIND_WITH_DBGHELP
+     CPPTRACE_FORCE_NO_INLINE
+     std::vector<frame_ptr> capture_frames(
+         std::size_t skip,
+         std::size_t max_depth,
+         EXCEPTION_POINTERS* exception_pointers = nullptr
+     );
+    #else
+     CPPTRACE_FORCE_NO_INLINE
+     std::vector<frame_ptr> capture_frames(std::size_t skip, std::size_t max_depth);
+    #endif
 
     CPPTRACE_FORCE_NO_INLINE
     std::size_t safe_capture_frames(frame_ptr* buffer, std::size_t size, std::size_t skip, std::size_t max_depth);
diff --git a/src/unwind/unwind_with_dbghelp.cpp b/src/unwind/unwind_with_dbghelp.cpp
@@ -24,40 +24,48 @@ namespace detail {
     #pragma warning(disable: 4740) // warning C4740: flow in or out of inline asm code suppresses global optimization
     #endif
     CPPTRACE_FORCE_NO_INLINE
-    std::vector<frame_ptr> capture_frames(std::size_t skip, std::size_t max_depth) {
+    std::vector<frame_ptr> capture_frames(
+        std::size_t skip,
+        std::size_t max_depth,
+        EXCEPTION_POINTERS* exception_pointers
+    ) {
         skip++;
         // https://jpassing.com/2008/03/12/walking-the-stack-of-the-current-thread/
 
         // Get current thread context
         // GetThreadContext cannot be used on the current thread.
         // RtlCaptureContext doesn't work on i386
         CONTEXT context;
-        #if defined(_M_IX86) || defined(__i386__)
         ZeroMemory(&context, sizeof(CONTEXT));
-        context.ContextFlags = CONTEXT_CONTROL;
-        #if IS_MSVC
-        __asm {
-            label:
-            mov [context.Ebp], ebp;
-            mov [context.Esp], esp;
-            mov eax, [label];
-            mov [context.Eip], eax;
+        if(exception_pointers) {
+            context = *exception_pointers->ContextRecord;
+        } else {
+            #if defined(_M_IX86) || defined(__i386__)
+             context.ContextFlags = CONTEXT_CONTROL;
+             #if IS_MSVC
+              __asm {
+                  label:
+                  mov [context.Ebp], ebp;
+                  mov [context.Esp], esp;
+                  mov eax, [label];
+                  mov [context.Eip], eax;
+              }
+             #else
+              asm(
+                  "label:\n\t"
+                  "mov{l %%ebp, %[cEbp] | %[cEbp], ebp};\n\t"
+                  "mov{l %%esp, %[cEsp] | %[cEsp], esp};\n\t"
+                  "mov{l $label, %%eax | eax, OFFSET label};\n\t"
+                  "mov{l %%eax, %[cEip] | %[cEip], eax};\n\t"
+                  : [cEbp] "=r" (context.Ebp),
+                    [cEsp] "=r" (context.Esp),
+                    [cEip] "=r" (context.Eip)
+              );
+             #endif
+            #else
+             RtlCaptureContext(&context);
+            #endif
         }
-        #else
-        asm(
-            "label:\n\t"
-            "mov{l %%ebp, %[cEbp] | %[cEbp], ebp};\n\t"
-            "mov{l %%esp, %[cEsp] | %[cEsp], esp};\n\t"
-            "mov{l $label, %%eax | eax, OFFSET label};\n\t"
-            "mov{l %%eax, %[cEip] | %[cEip], eax};\n\t"
-            : [cEbp] "=r" (context.Ebp),
-              [cEsp] "=r" (context.Esp),
-              [cEip] "=r" (context.Eip)
-        );
-        #endif
-        #else
-        RtlCaptureContext(&context);
-        #endif
         // Setup current frame
         STACKFRAME64 frame;
         ZeroMemory(&frame, sizeof(STACKFRAME64));
diff --git a/test/unit/lib/formatting.cpp b/test/unit/lib/formatting.cpp
