[SYCLomatic] Remove register storage class specifier which cause compiler error in C++17 code (#2848)

Signed-off-by: Jiang, Zhiwei <zhiwei.jiang@intel.com>

Author: zhiweij1

clang/include/clang/AST/Decl.h

@@ -260,6 +260,9 @@ class NamedDecl : public Decl {
 
 private:
   NamedDecl *getUnderlyingDeclImpl() LLVM_READONLY;
+#ifdef SYCLomatic_CUSTOMIZATION
+  SourceLocation StorageClassSpecLoc = SourceLocation();
+#endif
 
 protected:
   NamedDecl(Kind DK, DeclContext *DC, SourceLocation L, DeclarationName N)
@@ -487,6 +490,12 @@ class NamedDecl : public Decl {
 
   ObjCStringFormatFamily getObjCFStringFormattingFamily() const;
 
+#ifdef SYCLomatic_CUSTOMIZATION
+  SourceLocation getStorageClassSpecLoc() const { return StorageClassSpecLoc; }
+
+  void setStorageClassSpecLoc(SourceLocation Loc) { StorageClassSpecLoc = Loc; }
+#endif
+
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K >= firstNamed && K <= lastNamed; }
 };

clang/lib/DPCT/RulesLang/RulesLangNoneAPIAndType.cpp

@@ -41,6 +41,11 @@ extern DpctOption<opt, bool> ProcessAll;
 extern DpctOption<opt, bool> AsyncHandler;
 
 namespace clang {
+namespace ast_matchers {
+AST_MATCHER(VarDecl, hasRegisterStorage) {
+  return Node.getStorageClass() == SC_Register;
+}
+} // namespace ast_matchers
 namespace dpct {
 
 void LinkageSpecDeclRule::registerMatcher(MatchFinder &MF) {
@@ -1282,22 +1287,25 @@ void RemoveBaseClassRule::runRule(const MatchFinder::MatchResult &Result) {
   }
 }
 
-// The EDG frontend can allow code like below:
-//
-//     template <class T1, class T2> struct AAAAA {
-//       template <class T3> void foo(T3 x);
-//     };
-//     template <typename T4, typename T5>
-//     template <typename T6>
-//     void AAAAA<T4, T5>::foo<T6>(T6 x) {}
-//
-// But clang/gcc emits error.
-// We suppress the error in Sema and record the source range and remove
-// the "invalid" code in this rule.
 void CompatWithClangRule::registerMatcher(ast_matchers::MatchFinder &MF) {
+  // The EDG frontend can allow code like below:
+  //
+  //     template <class T1, class T2> struct AAAAA {
+  //       template <class T3> void foo(T3 x);
+  //     };
+  //     template <typename T4, typename T5>
+  //     template <typename T6>
+  //     void AAAAA<T4, T5>::foo<T6>(T6 x) {}
+  //
+  // But clang/gcc emits error.
+  // We suppress the error in Sema and record the source range and remove
+  // the "invalid" code in this rule.
   MF.addMatcher(
       cxxMethodDecl(hasParent(functionTemplateDecl())).bind("TemplateMethod"),
       this);
+  // ISO C++17 does not allow the 'register' storage class specifier. nvcc
+  // issues a warning when it encounters it, but keeps compiling.
+  MF.addMatcher(varDecl(hasRegisterStorage()).bind("RegisterStorage"), this);
 }
 
 void CompatWithClangRule::runRule(
@@ -1314,6 +1322,12 @@ void CompatWithClangRule::runRule(
       auto Length = End.getRawEncoding() - Begin.getRawEncoding();
       emplaceTransformation(new ReplaceText(Begin, Length, ""));
     }
+  } else if (const auto *VD =
+                 getNodeAsType<VarDecl>(Result, "RegisterStorage")) {
+    SourceLocation SL = VD->getStorageClassSpecLoc();
+    if (DpctGlobalInfo::getContext().getLangOpts().CUDA && SL.isValid()) {
+      emplaceTransformation(new ReplaceText(SL, std::strlen("register"), ""));
+    }
   }
 }
 

clang/lib/Sema/SemaDecl.cpp

@@ -7872,6 +7872,12 @@ NamedDecl *Sema::ActOnVariableDeclarator(
     }
   }
 
+#ifdef SYCLomatic_CUSTOMIZATION
+  if (SC != SC_None) {
+    NewVD->setStorageClassSpecLoc(D.getDeclSpec().getStorageClassSpecLoc());
+  }
+#endif
+
   // Set the lexical context. If the declarator has a C++ scope specifier, the
   // lexical context will be different from the semantic context.
   NewVD->setLexicalDeclContext(CurContext);
@@ -15288,6 +15294,11 @@ Decl *Sema::ActOnParamDeclarator(Scope *S, Declarator &D,
   if (getLangOpts().OpenCL)
     deduceOpenCLAddressSpace(New);
 
+#ifdef SYCLomatic_CUSTOMIZATION
+  if (SC != SC_None) {
+    New->setStorageClassSpecLoc(D.getDeclSpec().getStorageClassSpecLoc());
+  }
+#endif
   return New;
 }
 

clang/test/dpct/register_storage.cu

@@ -0,0 +1,10 @@
+// RUN: dpct --format-range=none --out-root %T/register_storage %s --cuda-include-path="%cuda-path/include"
+// RUN: FileCheck %s --match-full-lines --input-file %T/register_storage/register_storage.dp.cpp
+// RUN: %if build_lit %{icpx -c -fsycl %T/register_storage/register_storage.dp.cpp -o %T/register_storage/register_storage.dp.o %}
+
+// CHECK: void foo( int b) {
+// CHECK-NEXT:    int a = 5;
+// CHECK-NEXT: }
+void foo(register int b) {
+  register int a = 5;
+}