From ee5371268cbfe04728107177c3bbb2ac8deaf2fa Mon Sep 17 00:00:00 2001
From: Ryan Macnak <rmacnak@google.com>
Date: Wed, 4 Mar 2026 16:07:20 -0800
Subject: [PATCH] [vm, windows] Get DSO offsets without needing SymInitialize.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/60499
Change-Id: Ie9d45072e5a74522c22a99a18277ccbed53636b5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/485581
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
---
 runtime/vm/native_symbol_win.cc | 36 ++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/runtime/vm/native_symbol_win.cc b/runtime/vm/native_symbol_win.cc
index 1f55ab1e4c7..7e0dfce0d08 100644
--- a/runtime/vm/native_symbol_win.cc
+++ b/runtime/vm/native_symbol_win.cc
@@ -92,22 +92,48 @@ void NativeSymbolResolver::FreeSymbolName(const char* name) {
   free(const_cast<char*>(name));
 }
 
+struct Context {
+  uword pc;
+  uword dso_base;
+  const char* dso_name;
+  bool success;
+};
+
+BOOL CALLBACK EnumerateModulesCallback(PCSTR ModuleName,
+                                       DWORD64 ModuleBase,
+                                       ULONG ModuleSize,
+                                       PVOID UserContext) {
+  Context* context = reinterpret_cast<Context*>(UserContext);
+  if ((ModuleBase <= context->pc) && (context->pc < ModuleBase + ModuleSize)) {
+    context->dso_base = ModuleBase;
+    context->dso_name = Utils::StrDup(ModuleName);
+    context->success = true;
+    return FALSE;  // stop enumeration
+  }
+  return TRUE;  // continue enumeration
+}
+
 bool NativeSymbolResolver::LookupSharedObject(uword pc,
                                               uword* dso_base,
                                               const char** dso_name) {
 #ifdef DART_TARGET_OS_WINDOWS_UWP
   return false;
 #else
-  IMAGEHLP_MODULE64 info = {};
-  info.SizeOfStruct = sizeof(info);
-  if (!SymGetModuleInfo64(GetCurrentProcess(), pc, &info)) {
+  Context context;
+  context.pc = pc;
+  context.success = false;
+  if (!EnumerateLoadedModulesEx(GetCurrentProcess(), EnumerateModulesCallback,
+                                &context)) {
+    return false;
+  }
+  if (!context.success) {
     return false;
   }
   if (dso_base != nullptr) {
-    *dso_base = info.BaseOfImage;
+    *dso_base = context.dso_base;
   }
   if (dso_name != nullptr) {
-    *dso_name = Utils::StrDup(info.ImageName);
+    *dso_name = context.dso_name;
   }
   return true;
 #endif  // ifdef DART_TARGET_OS_WINDOWS_UWP