[clang] [clang][Driver] Allow -fuse-lld=lld-link when lto is enabled on *windows-msvc targets (PR #113966)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: Zhaoshi Zheng (zhaoshiz)

<details>
<summary>Changes</summary>

Follow-up on https://github.com/llvm/llvm-project/pull/109607, we have a use case on WoA where `cmake -G "Unix Makefiles"` generates -fuse-ld=lld-link, which is disallowed by PR#<!-- -->109607.

---
Full diff: https://github.com/llvm/llvm-project/pull/113966.diff


3 Files Affected:

- (modified) clang/lib/Driver/Driver.cpp (+1-1) 
- (modified) clang/test/Driver/clang_f_opts.c (+1) 
- (added) clang/test/Driver/woa-lto.c (+15) 


``````````diff
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 9878a9dad78d40..c1c581e6c6df7c 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -4035,7 +4035,7 @@ void Driver::handleArguments(Compilation &C, DerivedArgList &Args,
     if (C.getDefaultToolChain().getTriple().isWindowsMSVCEnvironment() &&
         LTOMode != LTOK_None &&
         !Args.getLastArgValue(options::OPT_fuse_ld_EQ)
-             .equals_insensitive("lld"))
+             .starts_with_insensitive("lld"))
       Diag(clang::diag::err_drv_lto_without_lld);
 
     // If -dumpdir is not specified, give a default prefix derived from the link
diff --git a/clang/test/Driver/clang_f_opts.c b/clang/test/Driver/clang_f_opts.c
index fd15552715cb35..2cfbe256bc7456 100644
--- a/clang/test/Driver/clang_f_opts.c
+++ b/clang/test/Driver/clang_f_opts.c
@@ -606,6 +606,7 @@
 // RUN: %clang -### -S -fjmc -g --target=x86_64-unknown-linux %s 2>&1 | FileCheck -check-prefix=CHECK_JMC %s
 // RUN: %clang -### -S -fjmc -g -fno-jmc --target=x86_64-unknown-linux %s 2>&1 | FileCheck -check-prefix=CHECK_NOJMC %s
 // RUN: %clang -### -fjmc -g -flto -fuse-ld=lld --target=x86_64-pc-windows-msvc %s 2>&1 | FileCheck -check-prefix=CHECK_NOJMC_LTO %s
+// RUN: %clang -### -fjmc -g -flto -fuse-ld=lld-link --target=x86_64-pc-windows-msvc %s 2>&1 | FileCheck -check-prefix=CHECK_NOJMC_LTO %s
 // RUN: %clang -### -fjmc -g -flto --target=x86_64-unknown-linux %s 2>&1 | FileCheck -check-prefix=CHECK_JMC_LTO %s
 // RUN: %clang -### -fjmc -g -flto -fno-jmc --target=x86_64-unknown-linux %s 2>&1 | FileCheck -check-prefix=CHECK_NOJMC_LTO %s
 // CHECK_JMC_WARN: -fjmc requires debug info. Use -g or debug options that enable debugger's stepping function; option ignored
diff --git a/clang/test/Driver/woa-lto.c b/clang/test/Driver/woa-lto.c
new file mode 100644
index 00000000000000..25c42374c4d449
--- /dev/null
+++ b/clang/test/Driver/woa-lto.c
@@ -0,0 +1,15 @@
+// REQUIRES: aarch64-registered-target
+//
+// RUN: echo "int main() {} " > %t.c
+//
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto -fuse-ld=lld -c %t.c -o %t.o
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto -fuse-ld=lld -### %t.o 2>&1 | FileCheck %s
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto=thin -fuse-ld=lld -c %t.c -o %t.o
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto=thin -fuse-ld=lld -### %t.o 2>&1 | FileCheck %s
+//
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto -fuse-ld=lld-link -c %t.c -o %t.o
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto -fuse-ld=lld-link -### %t.o 2>&1 | FileCheck %s
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto=thin -fuse-ld=lld-link -c %t.c -o %t.o
+// RUN: %clang --target=aarch64-pc-windows-msvc -O3 -flto=thin -fuse-ld=lld-link -### %t.o 2>&1 | FileCheck %s
+//
+// CHECK: "{{.*}}lld-link" "-out:a.exe" "-defaultlib:libcmt" "-defaultlib:oldnames"

``````````

</details>


https://github.com/llvm/llvm-project/pull/113966