[NFC][TableGen] Emit empty lines after/before namespace scope

Emit empty line after a namespace scope is opened and before its
closed. Adjust DirectiveEmitter code empty line emission in
response to this to avoid lot of unit test changes.

Author: jurahul

llvm/include/llvm/TableGen/CodeGenHelpers.h

@@ -20,6 +20,7 @@
 #include <string>
 
 namespace llvm {
+
 // Simple RAII helper for emitting ifdef-undef-endif scope.
 class IfDefEmitter {
 public:
@@ -57,15 +58,15 @@ class NamespaceEmitter {
   NamespaceEmitter(raw_ostream &OS, StringRef NameUntrimmed)
       : Name(trim(NameUntrimmed).str()), OS(OS) {
     if (!Name.empty())
-      OS << "namespace " << Name << " {\n";
+      OS << "namespace " << Name << " {\n\n";
   }
 
   ~NamespaceEmitter() { close(); }
 
   // Explicit function to close the namespace scopes.
   void close() {
     if (!Closed && !Name.empty())
-      OS << "} // namespace " << Name << "\n";
+      OS << "\n} // namespace " << Name << "\n";
     Closed = true;
   }
 

llvm/test/TableGen/directive1.td

@@ -61,6 +61,7 @@ def TDL_DirA : Directive<[Spelling<"dira">]> {
 // CHECK-NEXT:  #include <utility>
 // CHECK-EMPTY:
 // CHECK-NEXT:  namespace llvm {
+// CHECK-EMPTY:
 // CHECK-NEXT:  namespace tdl {
 // CHECK-EMPTY:
 // CHECK-NEXT:  LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();
@@ -176,6 +177,7 @@ def TDL_DirA : Directive<[Spelling<"dira">]> {
 // CHECK-NEXT:  template <> struct enum_iteration_traits<tdl::Clause> {
 // CHECK-NEXT:    static constexpr bool is_iterable = true;
 // CHECK-NEXT:  };
+// CHECK-EMPTY:
 // CHECK-NEXT:  } // namespace llvm
 // CHECK-EMPTY:
 // CHECK-NEXT:  #endif // LLVM_Tdl_INC

llvm/test/TableGen/directive2.td

@@ -54,6 +54,7 @@ def TDL_DirA : Directive<[Spelling<"dira">]> {
 // CHECK-NEXT:  #include <utility>
 // CHECK-EMPTY:
 // CHECK-NEXT:  namespace llvm {
+// CHECK-EMPTY:
 // CHECK-NEXT:  namespace tdl {
 // CHECK-EMPTY:
 // CHECK-NEXT:  enum class Association {
@@ -132,6 +133,7 @@ def TDL_DirA : Directive<[Spelling<"dira">]> {
 // CHECK-NEXT:  LLVM_ABI Association getDirectiveAssociation(Directive D);
 // CHECK-NEXT:  LLVM_ABI Category getDirectiveCategory(Directive D);
 // CHECK-NEXT:  LLVM_ABI SourceLanguage getDirectiveLanguages(Directive D);
+// CHECK-EMPTY:
 // CHECK-NEXT:  } // namespace tdl
 // CHECK-EMPTY:
 // CHECK-NEXT:  template <> struct enum_iteration_traits<tdl::Association> {
@@ -149,6 +151,7 @@ def TDL_DirA : Directive<[Spelling<"dira">]> {
 // CHECK-NEXT:  template <> struct enum_iteration_traits<tdl::Clause> {
 // CHECK-NEXT:    static constexpr bool is_iterable = true;
 // CHECK-NEXT:  };
+// CHECK-EMPTY:
 // CHECK-NEXT:  } // namespace llvm
 // CHECK-EMPTY:
 // CHECK-NEXT:  #endif // LLVM_Tdl_INC

llvm/utils/TableGen/Basic/DirectiveEmitter.cpp

@@ -81,14 +81,14 @@ static void generateEnumExports(ArrayRef<const Record *> Records,
     std::string N = getIdentifierName(R, Prefix);
     OS << "constexpr auto " << N << " = " << Enum << "::" << N << ";\n";
   }
+  OS << "\n";
 }
 
 // Generate enum class. Entries are emitted in the order in which they appear
 // in the `Records` vector.
 static void generateEnumClass(ArrayRef<const Record *> Records, raw_ostream &OS,
                               StringRef Enum, StringRef Prefix,
                               bool ExportEnums) {
-  OS << "\n";
   OS << "enum class " << Enum << " {\n";
   if (!Records.empty()) {
     std::string N;
@@ -104,17 +104,15 @@ static void generateEnumClass(ArrayRef<const Record *> Records, raw_ostream &OS,
   OS << "};\n";
   OS << "\n";
   OS << "static constexpr std::size_t " << Enum
-     << "_enumSize = " << Records.size() << ";\n";
+     << "_enumSize = " << Records.size() << ";\n\n";
 
   // Make the enum values available in the defined namespace. This allows us to
   // write something like Enum_X if we have a `using namespace <CppNamespace>`.
   // At the same time we do not loose the strong type guarantees of the enum
   // class, that is we cannot pass an unsigned as Directive without an explicit
   // cast.
-  if (ExportEnums) {
-    OS << "\n";
+  if (ExportEnums)
     generateEnumExports(Records, OS, Enum, Prefix);
-  }
 }
 
 // Generate enum class with values corresponding to different bit positions.
@@ -127,7 +125,6 @@ static void generateEnumBitmask(ArrayRef<const Record *> Records,
   StringRef Type = Records.size() <= 32 ? "uint32_t" : "uint64_t";
   StringRef TypeSuffix = Records.size() <= 32 ? "U" : "ULL";
 
-  OS << "\n";
   OS << "enum class " << Enum << " : " << Type << " {\n";
   std::string LastName;
   for (auto [I, R] : llvm::enumerate(Records)) {
@@ -138,17 +135,15 @@ static void generateEnumBitmask(ArrayRef<const Record *> Records,
   OS << "};\n";
   OS << "\n";
   OS << "static constexpr std::size_t " << Enum
-     << "_enumSize = " << Records.size() << ";\n";
+     << "_enumSize = " << Records.size() << ";\n\n";
 
   // Make the enum values available in the defined namespace. This allows us to
   // write something like Enum_X if we have a `using namespace <CppNamespace>`.
   // At the same time we do not loose the strong type guarantees of the enum
   // class, that is we cannot pass an unsigned as Directive without an explicit
   // cast.
-  if (ExportEnums) {
-    OS << "\n";
+  if (ExportEnums)
     generateEnumExports(Records, OS, Enum, Prefix);
-  }
 }
 
 // Generate enums for values that clauses can take.
@@ -170,7 +165,6 @@ static void generateClauseEnumVal(ArrayRef<const Record *> Records,
       return;
     }
 
-    OS << "\n";
     OS << "enum class " << Enum << " {\n";
     for (const EnumVal Val : ClauseVals)
       OS << "  " << Val.getRecordName() << "=" << Val.getValue() << ",\n";
@@ -182,6 +176,7 @@ static void generateClauseEnumVal(ArrayRef<const Record *> Records,
         OS << "constexpr auto " << CV->getName() << " = " << Enum
            << "::" << CV->getName() << ";\n";
       }
+      OS << "\n";
       EnumHelperFuncs += (Twine("LLVM_ABI ") + Twine(Enum) + Twine(" get") +
                           Twine(Enum) + Twine("(StringRef Str);\n"))
                              .str();
@@ -284,7 +279,7 @@ static void emitDirectivesDecl(const RecordKeeper &Records, raw_ostream &OS) {
   NamespaceEmitter DirLangNS(OS, DirLang.getCppNamespace());
 
   if (DirLang.hasEnableBitmaskEnumInNamespace())
-    OS << "\nLLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();\n";
+    OS << "LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();\n\n";
 
   // Emit Directive associations
   std::vector<const Record *> Associations;
@@ -315,7 +310,6 @@ static void emitDirectivesDecl(const RecordKeeper &Records, raw_ostream &OS) {
   generateClauseEnumVal(DirLang.getClauses(), OS, DirLang, EnumHelperFuncs);
 
   // Generic function signatures
-  OS << "\n";
   OS << "// Enumeration helper functions\n";
 
   OS << "LLVM_ABI std::pair<Directive, directive::VersionRange> get" << Lang
@@ -353,10 +347,7 @@ static void emitDirectivesDecl(const RecordKeeper &Records, raw_ostream &OS) {
   OS << "LLVM_ABI Association getDirectiveAssociation(Directive D);\n";
   OS << "LLVM_ABI Category getDirectiveCategory(Directive D);\n";
   OS << "LLVM_ABI SourceLanguage getDirectiveLanguages(Directive D);\n";
-  if (EnumHelperFuncs.length() > 0) {
-    OS << EnumHelperFuncs;
-    OS << "\n";
-  }
+  OS << EnumHelperFuncs;
 
   DirLangNS.close();
 

mlir/test/mlir-tblgen/cpp-class-comments.td

@@ -36,6 +36,7 @@ def A_SomeOp1 : Op<A_Dialect, "some_op1", []>{
 
   let cppNamespace = "OP1";
 // OP: namespace OP1
+// OP-EMPTY:
 // OP-NEXT: /// Some Op1 summary line1
 // OP-NEXT: /// summary line2
 // OP-NEXT: /// Some Op1 description
@@ -97,13 +98,15 @@ def EncodingTrait : AttrInterface<"EncodingTrait"> {
   let methods = [
   ];
 // ATTR-INTERFACE: namespace mlir::a::traits {
+// ATTR-INTERFACE-EMPTY:
 // ATTR-INTERFACE-NEXT: /// Common trait for all layouts.
 // ATTR-INTERFACE-NEXT: class EncodingTrait;
 }
 
 def SimpleEncodingTrait : AttrInterface<"SimpleEncodingTrait"> {
   let cppNamespace = "a::traits";
 // ATTR-INTERFACE: namespace a::traits {
+// ATTR-INTERFACE-EMPTY:
 // ATTR-INTERFACE-NEXT: class SimpleEncodingTrait;
 }
 
@@ -114,6 +117,7 @@ def SimpleOpInterface : OpInterface<"SimpleOpInterface"> {
     Simple Op Interface description
     }];
 // OP-INTERFACE: namespace a::traits {
+// OP-INTERFACE-EMPTY:
 // OP-INTERFACE-NEXT: /// Simple Op Interface description
 // OP-INTERFACE-NEXT: class SimpleOpInterface;
 }