From 04371c65faed0da0e24f23696d4ca8ca7cefa556 Mon Sep 17 00:00:00 2001
From: Daniel Lehman <dlehman@esri.com>
Date: Tue, 13 Jun 2017 14:05:49 -0700
Subject: [PATCH v3 1/3] msvcrt: Clean up registered C++ objects in handler.

v3: with changes from Piotr:
- simplify cxx_catch_cleanup
- compute tryblock end level and use it in cxx_local_unwind instead of using cxx_catch_unwind
ctx.rethrow only has the value FALSE
the following patches that add rethrow support will change as needed

v2:
- use __FINALLY_CTX macro

Signed-off-by: Daniel Lehman <dlehman@esri.com>
---
 dlls/msvcrt/except_x86_64.c | 72 +++++++++++++++++++--------------------------
 1 file changed, 31 insertions(+), 41 deletions(-)

diff --git a/dlls/msvcrt/except_x86_64.c b/dlls/msvcrt/except_x86_64.c
index 57fce93..6103005 100644
--- a/dlls/msvcrt/except_x86_64.c
+++ b/dlls/msvcrt/except_x86_64.c
@@ -110,6 +110,12 @@ typedef struct __cxx_function_descr
 
 typedef struct
 {
+    cxx_frame_info frame_info;
+    BOOL rethrow;
+} cxx_catch_ctx;
+
+typedef struct
+{
     ULONG64 dest_frame;
     ULONG64 orig_frame;
     DISPATCHER_CONTEXT *dispatch;
@@ -300,7 +306,7 @@ static void cxx_local_unwind(ULONG64 frame, DISPATCHER_CONTEXT *dispatch,
     }
 
     TRACE("current level: %d, last level: %d\n", trylevel, last_level);
-    while (trylevel != last_level)
+    while (trylevel > last_level)
     {
         if (trylevel<0 || trylevel>=descr->unwind_count)
         {
@@ -315,25 +321,35 @@ static void cxx_local_unwind(ULONG64 frame, DISPATCHER_CONTEXT *dispatch,
         }
         trylevel = unwind_table[trylevel].prev;
     }
-    unwind_help[0] = last_level;
+    unwind_help[0] = trylevel;
+}
+
+static void CALLBACK cxx_catch_cleanup(BOOL normal, void *c)
+{
+    cxx_catch_ctx *ctx = c;
+    __CxxUnregisterExceptionObject(&ctx->frame_info, ctx->rethrow);
 }
 
-static inline void* WINAPI call_catch_block(EXCEPTION_RECORD *rec)
+static void* WINAPI call_catch_block(EXCEPTION_RECORD *rec)
 {
     ULONG64 frame = rec->ExceptionInformation[1];
     const cxx_function_descr *descr = (void*)rec->ExceptionInformation[2];
     EXCEPTION_RECORD *prev_rec = (void*)rec->ExceptionInformation[4];
     void* (__cdecl *handler)(ULONG64 unk, ULONG64 rbp) = (void*)rec->ExceptionInformation[5];
     int *unwind_help = rva_to_ptr(descr->unwind_help, frame);
-    cxx_frame_info frame_info;
+    cxx_catch_ctx ctx;
     void *ret_addr;
 
     TRACE("calling handler %p\n", handler);
 
-    /* FIXME:  native does local_unwind here in case of exception rethrow */
-    __CxxRegisterExceptionObject(&prev_rec, &frame_info);
-    ret_addr = handler(0, frame);
-    __CxxUnregisterExceptionObject(&frame_info, FALSE);
+    ctx.rethrow = FALSE;
+    __CxxRegisterExceptionObject(&prev_rec, &ctx.frame_info);
+    __TRY
+    {
+        ret_addr = handler(0, frame);
+    }
+    __FINALLY_CTX(cxx_catch_cleanup, &ctx)
+
     unwind_help[0] = -2;
     unwind_help[1] = -1;
     return ret_addr;
@@ -469,6 +485,7 @@ static DWORD cxx_frame_handler(EXCEPTION_RECORD *rec, ULONG64 frame,
     DWORD throw_func_off;
     void *throw_func;
     UINT i, j;
+    int unwindlevel = -1;
 
     if (descr->magic<CXX_FRAME_MAGIC_VC6 || descr->magic>CXX_FRAME_MAGIC_VC8)
     {
@@ -502,6 +519,7 @@ static DWORD cxx_frame_handler(EXCEPTION_RECORD *rec, ULONG64 frame,
                 if (rva_to_ptr(catchblock->handler, dispatch->ImageBase) == throw_func)
                 {
                     TRACE("nested exception detected\n");
+                    unwindlevel = tryblock->end_level;
                     orig_frame = *(ULONG64*)rva_to_ptr(catchblock->frame, frame);
                     TRACE("setting orig_frame to %lx\n", orig_frame);
                 }
@@ -511,39 +529,11 @@ static DWORD cxx_frame_handler(EXCEPTION_RECORD *rec, ULONG64 frame,
 
     if (rec->ExceptionFlags & (EH_UNWINDING|EH_EXIT_UNWIND))
     {
-        if (cxx_is_consolidate(rec))
-        {
-            EXCEPTION_RECORD *new_rec = (void*)rec->ExceptionInformation[4];
-            thread_data_t *data = msvcrt_get_thread_data();
-            frame_info *cur;
-
-            if (rec->ExceptionFlags & EH_TARGET_UNWIND)
-            {
-                const cxx_function_descr *orig_descr = (void*)rec->ExceptionInformation[2];
-                int end_level = rec->ExceptionInformation[3];
-                orig_frame = rec->ExceptionInformation[1];
-
-                cxx_local_unwind(orig_frame, dispatch, orig_descr, end_level);
-            }
-            else if(frame == orig_frame)
-                cxx_local_unwind(frame, dispatch, descr, -1);
-
-            /* FIXME: we should only unregister frames registered by call_catch_block here */
-            for (cur = data->frame_info_head; cur; cur = cur->next)
-            {
-                if ((ULONG64)cur <= frame)
-                {
-                    __CxxUnregisterExceptionObject((cxx_frame_info*)cur,
-                            new_rec->ExceptionCode == CXX_EXCEPTION &&
-                            data->exc_record->ExceptionCode == CXX_EXCEPTION &&
-                            new_rec->ExceptionInformation[1] == data->exc_record->ExceptionInformation[1]);
-                }
-            }
-            return ExceptionContinueSearch;
-        }
-
-        if (frame == orig_frame)
-            cxx_local_unwind(frame, dispatch, descr, rec->ExceptionFlags & EH_TARGET_UNWIND ? trylevel : -1);
+        if (rec->ExceptionFlags & EH_TARGET_UNWIND)
+            cxx_local_unwind(orig_frame, dispatch, descr,
+                cxx_is_consolidate(rec) ? rec->ExceptionInformation[3] : trylevel);
+        else
+            cxx_local_unwind(orig_frame, dispatch, descr, unwindlevel);
         return ExceptionContinueSearch;
     }
     if (!descr->tryblock_count) return ExceptionContinueSearch;
-- 
1.9.5