[Parse] Remove unnecessary dependencies to Parser.h

C++ swift::Parser is going to be replaced with SwiftParser+ASTGen.
Direct dependencies to it should be removed. Before that, remove
unnecessary '#include "swift/Parse/Parser.h"' to clarify what actually
depends on 'swift::Parser'.

Split 'swift::parseDeclName()' et al. into the dedicated files.

include/swift/Frontend/Frontend.h

@@ -39,7 +39,6 @@
 #include "swift/IRGen/TBDGen.h"
 #include "swift/Migrator/MigratorOptions.h"
 #include "swift/Parse/IDEInspectionCallbacks.h"
-#include "swift/Parse/Parser.h"
 #include "swift/Sema/SourceLoader.h"
 #include "swift/Serialization/Validation.h"
 #include "swift/Subsystems.h"
@@ -52,9 +51,9 @@
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/BLAKE3.h"
 #include "llvm/Support/HashingOutputBackend.h"
-#include "llvm/TargetParser/Host.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/VirtualOutputBackend.h"
+#include "llvm/TargetParser/Host.h"
 
 #include <memory>
 

include/swift/Migrator/FixitFilter.h

@@ -18,6 +18,7 @@
 #define SWIFT_MIGRATOR_FIXITFILTER_H
 
 #include "swift/AST/DiagnosticConsumer.h"
+#include "swift/AST/DiagnosticsParse.h"
 #include "swift/AST/DiagnosticsSema.h"
 
 namespace swift {

include/swift/Parse/ParseDeclName.h

@@ -0,0 +1,100 @@
+//===--- ParseDeclName.h ----------------------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_PARSE_PARSEDECLNAME_H
+#define SWIFT_PARSE_PARSEDECLNAME_H
+
+#include "swift/AST/Identifier.h"
+#include "swift/Basic/LLVM.h"
+#include "swift/Parse/Lexer.h"
+
+namespace swift {
+
+/// Describes a parsed declaration name.
+struct ParsedDeclName {
+  /// The name of the context of which the corresponding entity should
+  /// become a member.
+  StringRef ContextName;
+
+  /// The base name of the declaration.
+  StringRef BaseName;
+
+  /// The argument labels for a function declaration.
+  SmallVector<StringRef, 4> ArgumentLabels;
+
+  /// Whether this is a function name (vs. a value name).
+  bool IsFunctionName = false;
+
+  /// Whether this is a getter for the named property.
+  bool IsGetter = false;
+
+  /// Whether this is a setter for the named property.
+  bool IsSetter = false;
+
+  bool IsSubscript = false;
+
+  /// For a declaration name that makes the declaration into an
+  /// instance member, the index of the "Self" parameter.
+  std::optional<unsigned> SelfIndex;
+
+  /// Determine whether this is a valid name.
+  explicit operator bool() const { return !BaseName.empty(); }
+
+  /// Whether this declaration name turns the declaration into a
+  /// member of some named context.
+  bool isMember() const { return !ContextName.empty(); }
+
+  /// Whether the result is translated into an instance member.
+  bool isInstanceMember() const {
+    return isMember() && static_cast<bool>(SelfIndex);
+  }
+
+  /// Whether the result is translated into a static/class member.
+  bool isClassMember() const {
+    return isMember() && !static_cast<bool>(SelfIndex);
+  }
+
+  /// Whether this is a property accessor.
+  bool isPropertyAccessor() const { return IsGetter || IsSetter; }
+
+  /// Whether this is an operator.
+  bool isOperator() const { return Lexer::isOperator(BaseName); }
+
+  /// Form a declaration name from this parsed declaration name.
+  DeclName formDeclName(ASTContext &ctx, bool isSubscript = false,
+                        bool isCxxClassTemplateSpec = false) const;
+
+  /// Form a declaration name from this parsed declaration name.
+  DeclNameRef formDeclNameRef(ASTContext &ctx, bool isSubscript = false,
+                              bool isCxxClassTemplateSpec = false) const;
+};
+
+/// Parse a stringified Swift declaration name,
+/// e.g. "Foo.translateBy(self:x:y:)".
+ParsedDeclName parseDeclName(StringRef name) LLVM_READONLY;
+
+/// Form a Swift declaration name from its constituent parts.
+DeclName formDeclName(ASTContext &ctx, StringRef baseName,
+                      ArrayRef<StringRef> argumentLabels, bool isFunctionName,
+                      bool isInitializer, bool isSubscript = false,
+                      bool isCxxClassTemplateSpec = false);
+
+/// Form a Swift declaration name reference from its constituent parts.
+DeclNameRef formDeclNameRef(ASTContext &ctx, StringRef baseName,
+                            ArrayRef<StringRef> argumentLabels,
+                            bool isFunctionName, bool isInitializer,
+                            bool isSubscript = false,
+                            bool isCxxClassTemplateSpec = false);
+
+} // namespace swift
+
+#endif // SWIFT_PARSE_PARSEDECLNAME_H

include/swift/Parse/Parser.h

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -2118,67 +2118,6 @@ public:
   ParserResult<Expr> parseExprFromSyntaxTree();
 };
 
-/// Describes a parsed declaration name.
-struct ParsedDeclName {
-  /// The name of the context of which the corresponding entity should
-  /// become a member.
-  StringRef ContextName;
-
-  /// The base name of the declaration.
-  StringRef BaseName;
-
-  /// The argument labels for a function declaration.
-  SmallVector<StringRef, 4> ArgumentLabels;
-
-  /// Whether this is a function name (vs. a value name).
-  bool IsFunctionName = false;
-
-  /// Whether this is a getter for the named property.
-  bool IsGetter = false;
-
-  /// Whether this is a setter for the named property.
-  bool IsSetter = false;
-
-  bool IsSubscript = false;
-
-  /// For a declaration name that makes the declaration into an
-  /// instance member, the index of the "Self" parameter.
-  std::optional<unsigned> SelfIndex;
-
-  /// Determine whether this is a valid name.
-  explicit operator bool() const { return !BaseName.empty(); }
-
-  /// Whether this declaration name turns the declaration into a
-  /// member of some named context.
-  bool isMember() const { return !ContextName.empty(); }
-
-  /// Whether the result is translated into an instance member.
-  bool isInstanceMember() const {
-    return isMember() && static_cast<bool>(SelfIndex);
-  }
-
-  /// Whether the result is translated into a static/class member.
-  bool isClassMember() const {
-    return isMember() && !static_cast<bool>(SelfIndex);
-  }
-
-  /// Whether this is a property accessor.
-  bool isPropertyAccessor() const { return IsGetter || IsSetter; }
-
-  /// Whether this is an operator.
-  bool isOperator() const {
-    return Lexer::isOperator(BaseName);
-  }
-
-  /// Form a declaration name from this parsed declaration name.
-  DeclName formDeclName(ASTContext &ctx, bool isSubscript = false,
-                        bool isCxxClassTemplateSpec = false) const;
-
-  /// Form a declaration name from this parsed declaration name.
-  DeclNameRef formDeclNameRef(ASTContext &ctx, bool isSubscript = false,
-                              bool isCxxClassTemplateSpec = false) const;
-};
-
 /// To assist debugging parser crashes, tell us the location of the
 /// current token.
 class PrettyStackTraceParser : public llvm::PrettyStackTraceEntry {
@@ -2188,28 +2127,6 @@ public:
   void print(llvm::raw_ostream &out) const override;
 };
 
-/// Parse a stringified Swift declaration name,
-/// e.g. "Foo.translateBy(self:x:y:)".
-ParsedDeclName parseDeclName(StringRef name) LLVM_READONLY;
-
-/// Form a Swift declaration name from its constituent parts.
-DeclName formDeclName(ASTContext &ctx,
-                      StringRef baseName,
-                      ArrayRef<StringRef> argumentLabels,
-                      bool isFunctionName,
-                      bool isInitializer,
-                      bool isSubscript = false,
-                      bool isCxxClassTemplateSpec = false);
-
-/// Form a Swift declaration name reference from its constituent parts.
-DeclNameRef formDeclNameRef(ASTContext &ctx,
-                            StringRef baseName,
-                            ArrayRef<StringRef> argumentLabels,
-                            bool isFunctionName,
-                            bool isInitializer,
-                            bool isSubscript = false,
-                            bool isCxxClassTemplateSpec = false);
-
 /// Whether a given token can be the start of a decl.
 bool isKeywordPossibleDeclStart(const LangOptions &options, const Token &Tok);