[llvm-branch-commits] [clang] release/21.x: [Driver][MinGW] Always put libc argument last, even if non-standard (#149434) (PR #151933)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport 7f470586e10543aa12efc7e04d4d4ac814eaca35

Requested by: @<!-- -->mstorsjo

---
Full diff: https://github.com/llvm/llvm-project/pull/151933.diff


2 Files Affected:

- (modified) clang/lib/Driver/ToolChains/MinGW.cpp (+9-2) 
- (modified) clang/test/Driver/mingw-msvcrt.c (+4-4) 


``````````diff
diff --git a/clang/lib/Driver/ToolChains/MinGW.cpp b/clang/lib/Driver/ToolChains/MinGW.cpp
index b2e36ae6f97c3..4894e6a52e93d 100644
--- a/clang/lib/Driver/ToolChains/MinGW.cpp
+++ b/clang/lib/Driver/ToolChains/MinGW.cpp
@@ -85,11 +85,18 @@ void tools::MinGW::Linker::AddLibGCC(const ArgList &Args,
 
   CmdArgs.push_back("-lmoldname");
   CmdArgs.push_back("-lmingwex");
-  for (auto Lib : Args.getAllArgValues(options::OPT_l))
+  for (auto Lib : Args.getAllArgValues(options::OPT_l)) {
     if (StringRef(Lib).starts_with("msvcr") ||
         StringRef(Lib).starts_with("ucrt") ||
-        StringRef(Lib).starts_with("crtdll"))
+        StringRef(Lib).starts_with("crtdll")) {
+      std::string CRTLib = (llvm::Twine("-l") + Lib).str();
+      // Respect the user's chosen crt variant, but still provide it
+      // again as the last linker argument, because some of the libraries
+      // we added above may depend on it.
+      CmdArgs.push_back(Args.MakeArgStringRef(CRTLib));
       return;
+    }
+  }
   CmdArgs.push_back("-lmsvcrt");
 }
 
diff --git a/clang/test/Driver/mingw-msvcrt.c b/clang/test/Driver/mingw-msvcrt.c
index 340ce1f57b0f8..e1648630476a0 100644
--- a/clang/test/Driver/mingw-msvcrt.c
+++ b/clang/test/Driver/mingw-msvcrt.c
@@ -7,10 +7,10 @@
 // CHECK_DEFAULT: "-lmingwex" "-lmsvcrt" "-ladvapi32"
 // CHECK_DEFAULT-SAME: "-lmsvcrt" "-lkernel32" "{{.*}}crtend.o"
 // CHECK_MSVCR120: "-lmsvcr120"
-// CHECK_MSVCR120-SAME: "-lmingwex" "-ladvapi32"
+// CHECK_MSVCR120-SAME: "-lmingwex" "-lmsvcr120" "-ladvapi32"
 // CHECK_UCRTBASE: "-lucrtbase"
-// CHECK_UCRTBASE-SAME: "-lmingwex" "-ladvapi32"
+// CHECK_UCRTBASE-SAME: "-lmingwex" "-lucrtbase" "-ladvapi32"
 // CHECK_UCRT: "-lucrt"
-// CHECK_UCRT-SAME: "-lmingwex" "-ladvapi32"
+// CHECK_UCRT-SAME: "-lmingwex" "-lucrt" "-ladvapi32"
 // CHECK_CRTDLL: "-lcrtdll"
-// CHECK_CRTDLL-SAME: "-lmingwex" "-ladvapi32"
+// CHECK_CRTDLL-SAME: "-lmingwex" "-lcrtdll" "-ladvapi32"

``````````

</details>


https://github.com/llvm/llvm-project/pull/151933