From 4dd3065cc065a8ab8ff354b7dffd47052e97129c Mon Sep 17 00:00:00 2001
From: luofeng14 <luofeng13@huawei.com>
Date: Fri, 8 Nov 2024 10:58:11 +0800
Subject: [PATCH] Add GNU compatibility for explicit instantiation cannot have
 a storage class.

---
 clang/lib/Basic/Diagnostic.cpp                 | 12 ++++++++++++
 clang/lib/Frontend/FrontendAction.cpp          | 12 ++++++++++++
 clang/test/Driver/test-error-compatibility.cpp |  9 +++++++++
 3 files changed, 33 insertions(+)
 create mode 100644 clang/test/Driver/test-error-compatibility.cpp

diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index 7a54d27ef9d8..e505203bdbab 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -355,13 +355,22 @@ void DiagnosticsEngine::setSeverity(diag::kind Diag, diag::Severity Map,
                                     SourceLocation L) {
   assert(Diag < diag::DIAG_UPPER_LIMIT &&
          "Can only map builtin diagnostics");
+#ifdef BUILD_FOR_OPENEULER
+  if (!(DiagOpts->GccCompatible)) {
+#endif
   assert((Diags->isBuiltinWarningOrExtension(Diag) ||
           (Map == diag::Severity::Fatal || Map == diag::Severity::Error)) &&
          "Cannot map errors into warnings!");
+#ifdef BUILD_FOR_OPENEULER
+  }
+#endif         
   assert((L.isInvalid() || SourceMgr) && "No SourceMgr for valid location");
 
   // Don't allow a mapping to a warning override an error/fatal mapping.
   bool WasUpgradedFromWarning = false;
+#ifdef BUILD_FOR_OPENEULER
+  if (!(DiagOpts->GccCompatible)) {
+#endif  
   if (Map == diag::Severity::Warning) {
     DiagnosticMapping &Info = GetCurDiagState()->getOrAddMapping(Diag);
     if (Info.getSeverity() == diag::Severity::Error ||
@@ -370,6 +379,9 @@ void DiagnosticsEngine::setSeverity(diag::kind Diag, diag::Severity Map,
       WasUpgradedFromWarning = true;
     }
   }
+#ifdef BUILD_FOR_OPENEULER
+   }
+#endif  
   DiagnosticMapping Mapping = makeUserMapping(Map, L);
   Mapping.setUpgradedFromWarning(WasUpgradedFromWarning);
 
diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index 0bd4b01ff79d..7b3b17a063f1 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -31,6 +31,9 @@
 #include "clang/Parse/ParseAST.h"
 #include "clang/Sema/HLSLExternalSemaSource.h"
 #include "clang/Sema/MultiplexExternalSemaSource.h"
+#ifdef BUILD_FOR_OPENEULER
+#include "clang/Sema/SemaDiagnostic.h"
+#endif
 #include "clang/Serialization/ASTDeserializationListener.h"
 #include "clang/Serialization/ASTReader.h"
 #include "clang/Serialization/GlobalModuleIndex.h"
@@ -1170,6 +1173,15 @@ void ASTFrontendAction::ExecuteAction() {
   if (!CI.hasSema())
     CI.createSema(getTranslationUnitKind(), CompletionConsumer);
 
+#ifdef BUILD_FOR_OPENEULER
+  if (CI.getLangOpts().GccCompatible) {
+    // error: explicit instantiation cannot have a storage class
+    CI.getSema().Diags.setSeverity(
+        diag::err_explicit_instantiation_storage_class, diag::Severity::Warning,
+        {});
+  }
+#endif
+
   ParseAST(CI.getSema(), CI.getFrontendOpts().ShowStats,
            CI.getFrontendOpts().SkipFunctionBodies);
 }
diff --git a/clang/test/Driver/test-error-compatibility.cpp b/clang/test/Driver/test-error-compatibility.cpp
new file mode 100644
index 000000000000..ec680411af9a
--- /dev/null
+++ b/clang/test/Driver/test-error-compatibility.cpp
@@ -0,0 +1,9 @@
+// REQUIRES: build_for_openeuler
+// RUN:   %clang -fgcc-compatible -c %s 2>&1 | FileCheck -check-prefix=CHECK-error %s
+// RUN: not %clang -c %s 2>&1 | FileCheck -check-prefix=CHECK-error %s
+// CHECK-error: explicit instantiation cannot have a storage class
+
+
+template <typename T> static void func() {}
+template static void func<int>(); // explicit instantiation
+
-- 
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