[Lldb-commits] [lldb] [lldb][windows] Use GetEnvironmentVariableW instead of _wgetenv (PR #199015)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lldb

Author: Charles Zablit (charles-zablit)

<details>
<summary>Changes</summary>

`_wgetenv` is not thread-safe per Microsoft docs:
https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/getenv-wgetenv?view=msvc-170.

Use `GetEnvironmentVariableW` with a sized buffer instead.

---
Full diff: https://github.com/llvm/llvm-project/pull/199015.diff


1 Files Affected:

- (modified) lldb/source/Host/windows/HostInfoWindows.cpp (+9-3) 


``````````diff
diff --git a/lldb/source/Host/windows/HostInfoWindows.cpp b/lldb/source/Host/windows/HostInfoWindows.cpp
index 0b0cda49a64c0..8f4cb63a4d18a 100644
--- a/lldb/source/Host/windows/HostInfoWindows.cpp
+++ b/lldb/source/Host/windows/HostInfoWindows.cpp
@@ -127,9 +127,15 @@ bool HostInfoWindows::GetEnvironmentVar(const std::string &var_name,
   if (!llvm::ConvertUTF8toWide(var_name, wvar_name))
     return false;
 
-  if (const wchar_t *wvar = _wgetenv(wvar_name.c_str()))
-    return llvm::convertWideToUTF8(wvar, var);
-  return false;
+  DWORD len = ::GetEnvironmentVariableW(wvar_name.c_str(), nullptr, 0);
+  if (len == 0)
+    return false;
+  std::vector<wchar_t> buffer(len);
+  DWORD written =
+      ::GetEnvironmentVariableW(wvar_name.c_str(), buffer.data(), len);
+  if (written == 0 || written >= len)
+    return false;
+  return llvm::convertWideToUTF8(buffer.data(), var);
 }
 
 static llvm::ManagedStatic<WindowsUserIDResolver> g_user_id_resolver;

``````````

</details>


https://github.com/llvm/llvm-project/pull/199015