[clang][driver] Support -x for all languages in CL mode

[huangqinjin]

After #68921, clang-cl gained option -x but only for CUDA/HIP. This commit simply removes the restriction on parameters to -x. Especially, it is able to use -x c++-module and -x c++-system-header to build C++20 modules and header units with clang-cl.

This effectively reverts commit fe08212.

Closes #88006.

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[llvmbot]

@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-clang

Author: None (huangqinjin)

Changes

After #68921, clang-cl gained option -x but only for CUDA/HIP. This commit simply removes the restriction on parameters to -x. Especially, it is able to use -x c++-module and -x c++-user-header to build C++20 modules and header units with clang-cl.

This effectively reverts commit fe08212.

Closes #88006.

---

Full diff: https://github.com/llvm/llvm-project/pull/89772.diff

2 Files Affected:

• (modified) clang/lib/Driver/Driver.cpp (+1-10)
• (modified) clang/test/Driver/x-args.c (-4)

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index e7335a61b10c53..0f425adfd32a6d 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -2636,22 +2636,13 @@ void Driver::BuildInputs(const ToolChain &TC, DerivedArgList &Args,
       Diag(clang::diag::note_drv_t_option_is_global);
   }
 
-  // CUDA/HIP and their preprocessor expansions can be accepted by CL mode.
   // Warn -x after last input file has no effect
-  auto LastXArg = Args.getLastArgValue(options::OPT_x);
-  const llvm::StringSet<> ValidXArgs = {"cuda", "hip", "cui", "hipi"};
-  if (!IsCLMode() || ValidXArgs.contains(LastXArg)) {
+  {
     Arg *LastXArg = Args.getLastArgNoClaim(options::OPT_x);
     Arg *LastInputArg = Args.getLastArgNoClaim(options::OPT_INPUT);
     if (LastXArg && LastInputArg &&
         LastInputArg->getIndex() < LastXArg->getIndex())
       Diag(clang::diag::warn_drv_unused_x) << LastXArg->getValue();
-  } else {
-    // In CL mode suggest /TC or /TP since -x doesn't make sense if passed via
-    // /clang:.
-    if (auto *A = Args.getLastArg(options::OPT_x))
-      Diag(diag::err_drv_unsupported_opt_with_suggestion)
-          << A->getAsString(Args) << "/TC' or '/TP";
   }
 
   for (Arg *A : Args) {
diff --git a/clang/test/Driver/x-args.c b/clang/test/Driver/x-args.c
index 17bb5d99404dae..b49f474babf0fa 100644
--- a/clang/test/Driver/x-args.c
+++ b/clang/test/Driver/x-args.c
@@ -5,7 +5,3 @@
 // RUN: %clang -fsyntax-only -xc %s -xc++ -fsyntax-only 2>&1 | FileCheck %s
 // RUN: %clang -fsyntax-only %s -xc %s -xc++ -fsyntax-only 2>&1 | FileCheck %s
 // CHECK: '-x c++' after last input file has no effect
-
-// RUN: not %clang_cl /WX /clang:-xc /clang:-E /clang:-dM -- %s 2>&1 | FileCheck --implicit-check-not="error:" -check-prefix=CL %s
-// RUN: not %clang_cl /TC /WX /clang:-xc /clang:-E /clang:-dM -- %s 2>&1 | FileCheck --implicit-check-not="error:" -check-prefix=CL %s
-// CL: error: unsupported option '-x c'; did you mean '/TC' or '/TP'?

[ChuanqiXu9]

It may be better to add a test with -x c++-module within CL mode.

[huangqinjin]

gentle ping. The ci failure looks not relevant.

[MaxEW707]

@huangqinjin The error is "fatal error C1060: compiler is out of heap space" which is unrelated. Just ran of out memory on the machine.

I haven't figured out how to resend the event to trigger a build retry without pushing an empty commit.
I usually just do git commit -m "rebuild" --allow-empty and then push that up to trigger a build retry.

Give that a shot to get CI green :).

[huangqinjin]

CI still fails. No idea how to proceed.

[MaxEW707]

@huangqinjin Try rebasing you changes on top of latest main. Looks like Windows CI is passing there including flang commits which are the source files that are causing msvc to run out of heap space.

[huangqinjin]

@huangqinjin Try rebasing you changes on top of latest main. Looks like Windows CI is passing there including flang commits which are the source files that are causing msvc to run out of heap space.

Thanks for the advice. CI green now.

[ChuanqiXu9]

I think we can land this given it is approved and the CI is green

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