chore: Simplify parsing of nested name specifiers

robertoraggi · robertoraggi · commit f0f7ca7ef47e · 2025-01-20T23:16:05.000+01:00
Signed-off-by: Roberto Raggi &lt;roberto.raggi@gmail.com&gt;
diff --git a/packages/cxx-frontend/src/AST.ts b/packages/cxx-frontend/src/AST.ts
@@ -11081,22 +11081,12 @@ export class DecltypeNestedNameSpecifierAST extends NestedNameSpecifierAST {
     return visitor.visitDecltypeNestedNameSpecifier(this, context);
   }
 
-  /**
-   * Returns the nestedNameSpecifier of this node
-   */
-  getNestedNameSpecifier(): NestedNameSpecifierAST | undefined {
-    return AST.from<NestedNameSpecifierAST>(
-      cxx.getASTSlot(this.getHandle(), 0),
-      this.parser,
-    );
-  }
-
   /**
    * Returns the decltypeSpecifier of this node
    */
   getDecltypeSpecifier(): DecltypeSpecifierAST | undefined {
     return AST.from<DecltypeSpecifierAST>(
-      cxx.getASTSlot(this.getHandle(), 1),
+      cxx.getASTSlot(this.getHandle(), 0),
       this.parser,
     );
   }
@@ -11105,7 +11095,7 @@ export class DecltypeNestedNameSpecifierAST extends NestedNameSpecifierAST {
    * Returns the location of the scope token in this node
    */
   getScopeToken(): Token | undefined {
-    return Token.from(cxx.getASTSlot(this.getHandle(), 2), this.parser);
+    return Token.from(cxx.getASTSlot(this.getHandle(), 1), this.parser);
   }
 }
 
diff --git a/packages/cxx-frontend/src/RecursiveASTVisitor.ts b/packages/cxx-frontend/src/RecursiveASTVisitor.ts
@@ -2527,7 +2527,6 @@ export class RecursiveASTVisitor<Context> extends ASTVisitor<Context, void> {
     node: ast.DecltypeNestedNameSpecifierAST,
     context: Context,
   ): void {
-    this.accept(node.getNestedNameSpecifier(), context);
     this.accept(node.getDecltypeSpecifier(), context);
   }
 
diff --git a/src/frontend/cxx/ast_printer.cc b/src/frontend/cxx/ast_printer.cc
@@ -2163,7 +2163,6 @@ void ASTPrinter::visit(SimpleNestedNameSpecifierAST* ast) {
 
 void ASTPrinter::visit(DecltypeNestedNameSpecifierAST* ast) {
   out_ << std::format("{}\n", "decltype-nested-name-specifier");
-  accept(ast->nestedNameSpecifier, "nested-name-specifier");
   accept(ast->decltypeSpecifier, "decltype-specifier");
 }
 
diff --git a/src/mlir/cxx/mlir/codegen.cc b/src/mlir/cxx/mlir/codegen.cc
@@ -2632,7 +2632,6 @@ auto Codegen::NestedNameSpecifierVisitor::operator()(
 
 auto Codegen::NestedNameSpecifierVisitor::operator()(
     DecltypeNestedNameSpecifierAST* ast) -> NestedNameSpecifierResult {
-  auto nestedNameSpecifierResult = gen(ast->nestedNameSpecifier);
   auto decltypeSpecifierResult = gen(ast->decltypeSpecifier);
 
   return {};
diff --git a/src/parser/cxx/ast.cc b/src/parser/cxx/ast.cc
@@ -2931,7 +2931,6 @@ auto SimpleNestedNameSpecifierAST::lastSourceLocation() -> SourceLocation {
 }
 
 auto DecltypeNestedNameSpecifierAST::firstSourceLocation() -> SourceLocation {
-  if (auto loc = cxx::firstSourceLocation(nestedNameSpecifier)) return loc;
   if (auto loc = cxx::firstSourceLocation(decltypeSpecifier)) return loc;
   if (auto loc = cxx::firstSourceLocation(scopeLoc)) return loc;
   return {};
@@ -2940,7 +2939,6 @@ auto DecltypeNestedNameSpecifierAST::firstSourceLocation() -> SourceLocation {
 auto DecltypeNestedNameSpecifierAST::lastSourceLocation() -> SourceLocation {
   if (auto loc = cxx::lastSourceLocation(scopeLoc)) return loc;
   if (auto loc = cxx::lastSourceLocation(decltypeSpecifier)) return loc;
-  if (auto loc = cxx::lastSourceLocation(nestedNameSpecifier)) return loc;
   return {};
 }
 
diff --git a/src/parser/cxx/ast.fbs b/src/parser/cxx/ast.fbs
@@ -1330,7 +1330,6 @@ table SimpleNestedNameSpecifier /* NestedNameSpecifierAST */ {
 }
 
 table DecltypeNestedNameSpecifier /* NestedNameSpecifierAST */ {
-  nested_name_specifier: NestedNameSpecifier;
   decltype_specifier: DecltypeSpecifier;
   scope_loc: uint32;
 }
diff --git a/src/parser/cxx/ast.h b/src/parser/cxx/ast.h
@@ -3558,7 +3558,6 @@ class DecltypeNestedNameSpecifierAST final : public NestedNameSpecifierAST {
 
   DecltypeNestedNameSpecifierAST() : NestedNameSpecifierAST(Kind) {}
 
-  NestedNameSpecifierAST* nestedNameSpecifier = nullptr;
   DecltypeSpecifierAST* decltypeSpecifier = nullptr;
   SourceLocation scopeLoc;
 
diff --git a/src/parser/cxx/ast_interpreter.cc b/src/parser/cxx/ast_interpreter.cc
@@ -1795,7 +1795,6 @@ auto ASTInterpreter::NestedNameSpecifierVisitor::operator()(
 
 auto ASTInterpreter::NestedNameSpecifierVisitor::operator()(
     DecltypeNestedNameSpecifierAST* ast) -> NestedNameSpecifierResult {
-  auto nestedNameSpecifierResult = accept(ast->nestedNameSpecifier);
   auto decltypeSpecifierResult = accept(ast->decltypeSpecifier);
 
   return {};
diff --git a/src/parser/cxx/ast_rewriter.cc b/src/parser/cxx/ast_rewriter.cc
@@ -3319,7 +3319,6 @@ auto ASTRewriter::NestedNameSpecifierVisitor::operator()(
   auto copy = new (arena()) DecltypeNestedNameSpecifierAST{};
 
   copy->symbol = ast->symbol;
-  copy->nestedNameSpecifier = rewrite(ast->nestedNameSpecifier);
   copy->decltypeSpecifier =
       ast_cast<DecltypeSpecifierAST>(rewrite(ast->decltypeSpecifier));
   copy->scopeLoc = ast->scopeLoc;
diff --git a/src/parser/cxx/ast_slot.cc b/src/parser/cxx/ast_slot.cc
@@ -5408,24 +5408,19 @@ void ASTSlot::visit(SimpleNestedNameSpecifierAST* ast) {
 
 void ASTSlot::visit(DecltypeNestedNameSpecifierAST* ast) {
   switch (slot_) {
-    case 0:  // nestedNameSpecifier
-      value_ = reinterpret_cast<std::intptr_t>(ast->nestedNameSpecifier);
-      slotKind_ = ASTSlotKind::kNode;
-      slotNameIndex_ = SlotNameIndex{140};
-      break;
-    case 1:  // decltypeSpecifier
+    case 0:  // decltypeSpecifier
       value_ = reinterpret_cast<std::intptr_t>(ast->decltypeSpecifier);
       slotKind_ = ASTSlotKind::kNode;
       slotNameIndex_ = SlotNameIndex{58};
       break;
-    case 2:  // scopeLoc
+    case 1:  // scopeLoc
       value_ = ast->scopeLoc.index();
       slotKind_ = ASTSlotKind::kToken;
       slotNameIndex_ = SlotNameIndex{177};
       break;
   }  // switch
 
-  slotCount_ = 3;
+  slotCount_ = 2;
 }
 
 void ASTSlot::visit(TemplateNestedNameSpecifierAST* ast) {
diff --git a/src/parser/cxx/flatbuffers/ast_decoder.cc b/src/parser/cxx/flatbuffers/ast_decoder.cc
@@ -3940,8 +3940,6 @@ auto ASTDecoder::decodeDecltypeNestedNameSpecifier(
   if (!node) return nullptr;
 
   auto ast = new (pool_) DecltypeNestedNameSpecifierAST();
-  ast->nestedNameSpecifier = decodeNestedNameSpecifier(
-      node->nested_name_specifier(), node->nested_name_specifier_type());
   ast->decltypeSpecifier = decodeDecltypeSpecifier(node->decltype_specifier());
   ast->scopeLoc = SourceLocation(node->scope_loc());
   return ast;
diff --git a/src/parser/cxx/flatbuffers/ast_encoder.cc b/src/parser/cxx/flatbuffers/ast_encoder.cc
@@ -4547,15 +4547,9 @@ void ASTEncoder::visit(SimpleNestedNameSpecifierAST* ast) {
 }
 
 void ASTEncoder::visit(DecltypeNestedNameSpecifierAST* ast) {
-  const auto [nestedNameSpecifier, nestedNameSpecifierType] =
-      acceptNestedNameSpecifier(ast->nestedNameSpecifier);
-
   const auto decltypeSpecifier = accept(ast->decltypeSpecifier);
 
   io::DecltypeNestedNameSpecifier::Builder builder{fbb_};
-  builder.add_nested_name_specifier(nestedNameSpecifier);
-  builder.add_nested_name_specifier_type(
-      static_cast<io::NestedNameSpecifier>(nestedNameSpecifierType));
   builder.add_decltype_specifier(decltypeSpecifier.o);
   builder.add_scope_loc(ast->scopeLoc.index());
 
diff --git a/src/parser/cxx/parser.cc b/src/parser/cxx/parser.cc
@@ -1596,23 +1596,7 @@ void Parser::parse_optional_nested_name_specifier(
 
 auto Parser::parse_nested_name_specifier(NestedNameSpecifierAST*& yyast)
     -> bool {
-  auto lookat_global_nested_name_specifier = [&] {
-    if (yyast) return false;
-
-    SourceLocation scopeLoc;
-    if (!match(TokenKind::T_COLON_COLON, scopeLoc)) return false;
-
-    auto ast = make_node<GlobalNestedNameSpecifierAST>(pool_);
-    yyast = ast;
-    ast->scopeLoc = scopeLoc;
-    ast->symbol = globalScope_->owner();
-
-    return true;
-  };
-
   auto lookat_decltype_nested_name_specifier = [&] {
-    if (yyast) return false;
-
     LookaheadParser lookahead{this};
 
     DecltypeSpecifierAST* decltypeSpecifier = nullptr;
@@ -1624,7 +1608,6 @@ auto Parser::parse_nested_name_specifier(NestedNameSpecifierAST*& yyast)
     lookahead.commit();
 
     auto ast = make_node<DecltypeNestedNameSpecifierAST>(pool_);
-    ast->nestedNameSpecifier = yyast;
     yyast = ast;
 
     ast->decltypeSpecifier = decltypeSpecifier;
@@ -1704,14 +1687,18 @@ auto Parser::parse_nested_name_specifier(NestedNameSpecifierAST*& yyast)
 
   yyast = nullptr;
 
+  if (SourceLocation scopeLoc; match(TokenKind::T_COLON_COLON, scopeLoc)) {
+    auto ast = make_node<GlobalNestedNameSpecifierAST>(pool_);
+    yyast = ast;
+    ast->scopeLoc = scopeLoc;
+    ast->symbol = globalScope_->owner();
+  } else if (lookat_decltype_nested_name_specifier()) {
+    //
+  }
+
   while (true) {
-    if (lookat_global_nested_name_specifier())
-      continue;
-    else if (lookat_simple_nested_name_specifier())
-      continue;
-    else if (lookat_decltype_nested_name_specifier())
-      continue;
-    else if (lookat_template_nested_name_specifier())
+    if (lookat_simple_nested_name_specifier()) continue;
+    if (lookat_template_nested_name_specifier())
       continue;
     else
       break;

Original file line number	Diff line number	Diff line change
`@@ -2527,7 +2527,6 @@ export class RecursiveASTVisitor<Context> extends ASTVisitor<Context, void> {`
`2527`	`2527`	`node: ast.DecltypeNestedNameSpecifierAST,`
`2528`	`2528`	`context: Context,`
`2529`	`2529`	`): void {`
`2530`		`- this.accept(node.getNestedNameSpecifier(), context);`
`2531`	`2530`	`this.accept(node.getDecltypeSpecifier(), context);`
`2532`	`2531`	`}`
`2533`	`2532`
Original file line number	Diff line number	Diff line change
`@@ -2163,7 +2163,6 @@ void ASTPrinter::visit(SimpleNestedNameSpecifierAST* ast) {`
`2163`	`2163`
`2164`	`2164`	`void ASTPrinter::visit(DecltypeNestedNameSpecifierAST* ast) {`
`2165`	`2165`	`out_ << std::format("{}\n", "decltype-nested-name-specifier");`
`2166`		`- accept(ast->nestedNameSpecifier, "nested-name-specifier");`
`2167`	`2166`	`accept(ast->decltypeSpecifier, "decltype-specifier");`
`2168`	`2167`	`}`
`2169`	`2168`
Original file line number	Diff line number	Diff line change
`@@ -2931,7 +2931,6 @@ auto SimpleNestedNameSpecifierAST::lastSourceLocation() -> SourceLocation {`
`2931`	`2931`	`}`
`2932`	`2932`
`2933`	`2933`	`auto DecltypeNestedNameSpecifierAST::firstSourceLocation() -> SourceLocation {`
`2934`		`- if (auto loc = cxx::firstSourceLocation(nestedNameSpecifier)) return loc;`
`2935`	`2934`	`if (auto loc = cxx::firstSourceLocation(decltypeSpecifier)) return loc;`
`2936`	`2935`	`if (auto loc = cxx::firstSourceLocation(scopeLoc)) return loc;`
`2937`	`2936`	`return {};`
`@@ -2940,7 +2939,6 @@ auto DecltypeNestedNameSpecifierAST::firstSourceLocation() -> SourceLocation {`
`2940`	`2939`	`auto DecltypeNestedNameSpecifierAST::lastSourceLocation() -> SourceLocation {`
`2941`	`2940`	`if (auto loc = cxx::lastSourceLocation(scopeLoc)) return loc;`
`2942`	`2941`	`if (auto loc = cxx::lastSourceLocation(decltypeSpecifier)) return loc;`
`2943`		`- if (auto loc = cxx::lastSourceLocation(nestedNameSpecifier)) return loc;`
`2944`	`2942`	`return {};`
`2945`	`2943`	`}`
`2946`	`2944`
Original file line number	Diff line number	Diff line change
`@@ -1330,7 +1330,6 @@ table SimpleNestedNameSpecifier /* NestedNameSpecifierAST */ {`
`1330`	`1330`	`}`
`1331`	`1331`
`1332`	`1332`	`table DecltypeNestedNameSpecifier /* NestedNameSpecifierAST */ {`
`1333`		`- nested_name_specifier: NestedNameSpecifier;`
`1334`	`1333`	`decltype_specifier: DecltypeSpecifier;`
`1335`	`1334`	`scope_loc: uint32;`
`1336`	`1335`	`}`