[clang] [clang][MinGW] Always link ntdll.dll (PR #162997)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: cqwrteur (trcrsired)

<details>
<summary>Changes</summary>

GCC with MCF threads has already linked ntdll.dll for serveral years. First, all supported windows versions are NT-based and even on 9x OSes such as Windows 95, ntdll.dll still exists. Plus the linker won't link to ntdll.dll if user does not use any ntdll functions.

There is no reason not to link ntdll.dll when kernel32.dll is always linked

https://github.com/gcc-mirror/gcc/blob/master/gcc/config/mingw/mingw32.h#L199 

---
Full diff: https://github.com/llvm/llvm-project/pull/162997.diff


2 Files Affected:

- (modified) clang/lib/Driver/ToolChains/MinGW.cpp (+4-1) 
- (modified) clang/test/Driver/mingw-windowsapp.c (+1-1) 


``````````diff
diff --git a/clang/lib/Driver/ToolChains/MinGW.cpp b/clang/lib/Driver/ToolChains/MinGW.cpp
index 1bb9bcfe6aab2..336e236cfdd58 100644
--- a/clang/lib/Driver/ToolChains/MinGW.cpp
+++ b/clang/lib/Driver/ToolChains/MinGW.cpp
@@ -359,14 +359,17 @@ void tools::MinGW::Linker::ConstructJob(Compilation &C, const JobAction &JA,
         CmdArgs.push_back("-lshell32");
         CmdArgs.push_back("-luser32");
         CmdArgs.push_back("-lkernel32");
+        CmdArgs.push_back("-lntdll");
       }
 
       if (Args.hasArg(options::OPT_static)) {
         CmdArgs.push_back("--end-group");
       } else {
         AddLibGCC(Args, CmdArgs);
-        if (!HasWindowsApp)
+        if (!HasWindowsApp) {
           CmdArgs.push_back("-lkernel32");
+          CmdArgs.push_back("-lntdll");
+        }
       }
     }
 
diff --git a/clang/test/Driver/mingw-windowsapp.c b/clang/test/Driver/mingw-windowsapp.c
index d0a44952b30a3..50950c0195995 100644
--- a/clang/test/Driver/mingw-windowsapp.c
+++ b/clang/test/Driver/mingw-windowsapp.c
@@ -1,6 +1,6 @@
 // RUN: %clang -v --target=i686-pc-windows-gnu -### %s 2>&1 | FileCheck -check-prefix=CHECK_DEFAULT %s
 // RUN: %clang -v --target=i686-pc-windows-gnu -### %s -lwindowsapp 2>&1 | FileCheck -check-prefix=CHECK_WINDOWSAPP %s
 
-// CHECK_DEFAULT: "-lmsvcrt" "-ladvapi32" "-lshell32" "-luser32" "-lkernel32" "-lmingw32"
+// CHECK_DEFAULT: "-lmsvcrt" "-ladvapi32" "-lshell32" "-luser32" "-lkernel32" "-lntdll" "-lmingw32"
 // CHECK_WINDOWSAPP: "-lwindowsapp" "-lmingw32"
 // CHECK_WINDOWSAPP-SAME: "-lmsvcrt" "-lmingw32"

``````````

</details>


https://github.com/llvm/llvm-project/pull/162997