[clang] cc1eae6 - [flang][OpenMP] Remove experimental warning (#144915)

[via cfe-commits]

Author: Tom Eccles
Date: 2025-06-26T14:09:21+01:00
New Revision: cc1eae6ea2de5ccadb81a182b9f0de2128b9fefc

URL: https://github.com/llvm/llvm-project/commit/cc1eae6ea2de5ccadb81a182b9f0de2128b9fefc
DIFF: https://github.com/llvm/llvm-project/commit/cc1eae6ea2de5ccadb81a182b9f0de2128b9fefc.diff

LOG: [flang][OpenMP] Remove experimental warning (#144915)

RFC:
https://discourse.llvm.org/t/rfc-removing-the-openmp-experimental-warning-for-llvm-21/86455

Fixes: #110008

Added: 
    

Modified: 
    clang/include/clang/Basic/DiagnosticDriverKinds.td
    clang/lib/Driver/ToolChains/Flang.cpp
    flang/lib/Frontend/CompilerInvocation.cpp
    flang/test/Driver/fopenmp.f90

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
index 29f6480ba935c..68f87ebb1b39f 100644
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -143,8 +143,8 @@ def warn_drv_unsupported_option_for_processor : Warning<
 def warn_drv_unsupported_openmp_library : Warning<
   "the library '%0=%1' is not supported, OpenMP will not be enabled">,
   InGroup<OptionIgnored>;
-def warn_openmp_experimental : Warning<
-  "OpenMP support in flang is still experimental">,
+def warn_openmp_incomplete : Warning<
+  "OpenMP support for version %0 in flang is still incomplete">,
   InGroup<ExperimentalOption>;
 
 def err_drv_invalid_thread_model_for_target : Error<

diff  --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index 47d0e345086b2..e4e321ba1e195 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -906,9 +906,6 @@ void Flang::ConstructJob(Compilation &C, const JobAction &JA,
 
       if (Args.hasArg(options::OPT_fopenmp_force_usm))
         CmdArgs.push_back("-fopenmp-force-usm");
-      // TODO: OpenMP support isn't "done" yet, so for now we warn that it
-      // is experimental.
-      D.Diag(diag::warn_openmp_experimental);
 
       // FIXME: Clang supports a whole bunch more flags here.
       break;

diff  --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 07d6814da8671..766131fd69d85 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -1138,8 +1138,9 @@ static bool parseOpenMPArgs(CompilerInvocation &res, llvm::opt::ArgList &args,
   unsigned numErrorsBefore = diags.getNumErrors();
   llvm::Triple t(res.getTargetOpts().triple);
 
-  // By default OpenMP is set to 3.1 version
-  res.getLangOpts().OpenMPVersion = 31;
+  constexpr unsigned newestFullySupported = 31;
+  // By default OpenMP is set to the most recent fully supported version
+  res.getLangOpts().OpenMPVersion = newestFullySupported;
   res.getFrontendOpts().features.Enable(
       Fortran::common::LanguageFeature::OpenMP);
   if (auto *arg =
@@ -1164,6 +1165,9 @@ static bool parseOpenMPArgs(CompilerInvocation &res, llvm::opt::ArgList &args,
     if (!value.getAsInteger(/*radix=*/10, version)) {
       if (llvm::is_contained(ompVersions, version)) {
         res.getLangOpts().OpenMPVersion = version;
+
+        if (version > newestFullySupported)
+          diags.Report(clang::diag::warn_openmp_incomplete) << version;
       } else if (llvm::is_contained(oldVersions, version)) {
         const unsigned diagID =
             diags.getCustomDiagID(clang::DiagnosticsEngine::Warning,

diff  --git a/flang/test/Driver/fopenmp.f90 b/flang/test/Driver/fopenmp.f90
index b3c3547800bdb..f7e83e0eeb734 100644
--- a/flang/test/Driver/fopenmp.f90
+++ b/flang/test/Driver/fopenmp.f90
@@ -74,6 +74,6 @@
 ! CHECK-LD-ANYMD: "{{.*}}ld{{(.exe)?}}"
 ! CHECK-LD-ANYMD: "-l{{(omp|gomp|iomp5md)}}"
 !
-! RUN: %flang -fopenmp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-EXPERIMENTAL
+! RUN: %flang -fopenmp -fopenmp-version=40 -c %s -S -o - 2>&1 | FileCheck %s --check-prefix=CHECK-INCOMPLETE
 !
-! CHECK-EXPERIMENTAL: flang{{.*}}: warning: OpenMP support in flang is still experimental
+! CHECK-INCOMPLETE: warning: OpenMP support for version 40 in flang is still incomplete