Alexandre Julliard : msvcrt: Reimplement __crtCapturePreviousContext() based on RtlWalkFrameChain().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 356be34dcd2b1acfaa55c5d896b06a2628d41dfe
URL:    https://gitlab.winehq.org/wine/wine/-/commit/356be34dcd2b1acfaa55c5d896b06a2...

Author: Alexandre Julliard 
Date:   Fri Jun  7 10:19:57 2024 +0200

msvcrt: Reimplement __crtCapturePreviousContext() based on RtlWalkFrameChain().

---

dlls/msvcrt/except_arm64ec.c | 20 +++++++++++++++++++-
 dlls/msvcrt/except_x86_64.c  | 36 ++++++++++++++----------------------
 2 files changed, 33 insertions(+), 23 deletions(-)

diff --git a/dlls/msvcrt/except_arm64ec.c b/dlls/msvcrt/except_arm64ec.c
index 12790cee7d8..b2e723f79b3 100644
--- a/dlls/msvcrt/except_arm64ec.c
+++ b/dlls/msvcrt/except_arm64ec.c
@@ -144,7 +144,25 @@ int handle_fpieee_flt( __msvcrt_ulong exception_code, EXCEPTION_POINTERS *ep,
  */
 void __cdecl __crtCapturePreviousContext( CONTEXT *ctx )
 {
-    FIXME("not implemented\n");
+    UNWIND_HISTORY_TABLE table;
+    RUNTIME_FUNCTION *func;
+    PEXCEPTION_ROUTINE handler;
+    ULONG_PTR pc, frame, base;
+    void *data;
+    ULONG i;
+
+    RtlCaptureContext( ctx );
+    for (i = 0; i < 2; i++)
+    {
+        pc = ctx->Rip;
+        if ((ctx->ContextFlags & CONTEXT_UNWOUND_TO_CALL) && RtlIsEcCode( pc )) pc -= 4;
+        if (!(func = RtlLookupFunctionEntry( pc, &base, &table ))) break;
+        if (RtlVirtualUnwind2( UNW_FLAG_NHANDLER, base, pc, func, ctx, NULL,
+                               &data, &frame, NULL, NULL, NULL, &handler, 0 ))
+            break;
+        if (!ctx->Rip) break;
+        if (!frame) break;
+    }
 }
 #endif

diff --git a/dlls/msvcrt/except_x86_64.c b/dlls/msvcrt/except_x86_64.c
index 1c3cc62bc7f..e0fda975be4 100644
--- a/dlls/msvcrt/except_x86_64.c
+++ b/dlls/msvcrt/except_x86_64.c
@@ -133,33 +133,25 @@ int handle_fpieee_flt( __msvcrt_ulong exception_code, EXCEPTION_POINTERS *ep,
 /*********************************************************************
  *  __crtCapturePreviousContext (MSVCR110.@)
  */
-void __cdecl get_prev_context(CONTEXT *ctx, DWORD64 rip)
+void __cdecl __crtCapturePreviousContext( CONTEXT *ctx )
 {
-    ULONG64 frame, image_base;
-    RUNTIME_FUNCTION *rf;
+    UNWIND_HISTORY_TABLE table;
+    RUNTIME_FUNCTION *func;
+    PEXCEPTION_ROUTINE handler;
+    ULONG_PTR frame, base;
     void *data;
+    ULONG i;

-    TRACE("(%p)\n", ctx);
-
-    rf = RtlLookupFunctionEntry(ctx->Rip, &image_base, NULL);
-    if(!rf) {
-        FIXME("RtlLookupFunctionEntry failed\n");
-        return;
+    RtlCaptureContext( ctx );
+    for (i = 0; i < 2; i++)
+    {
+        if (!(func = RtlLookupFunctionEntry( ctx->Rip, &base, &table ))) break;
+        if (RtlVirtualUnwind2( UNW_FLAG_NHANDLER, base, ctx->Rip, func, ctx, NULL,
+                               &data, &frame, NULL, NULL, NULL, &handler, 0 )) break;
+        if (!ctx->Rip) break;
+        if (!frame) break;
     }
-
-    RtlVirtualUnwind(UNW_FLAG_NHANDLER, image_base, ctx->Rip,
-            rf, ctx, &data, &frame, NULL);
 }
-
-__ASM_GLOBAL_FUNC( __crtCapturePreviousContext,
-                   "movq %rcx,8(%rsp)\n\t"
-                   "call " __ASM_NAME("RtlCaptureContext") "\n\t"
-                   "movq 8(%rsp),%rcx\n\t"     /* context */
-                   "leaq 8(%rsp),%rax\n\t"
-                   "movq %rax,0x98(%rcx)\n\t"  /* context->Rsp */
-                   "movq (%rsp),%rax\n\t"
-                   "movq %rax,0xf8(%rcx)\n\t"  /* context->Rip */
-                   "jmp " __ASM_NAME("get_prev_context") )
 #endif

#endif  /* __x86_64__ */