path: root/include/clang/Sema/CodeCompleteConsumer.h

//===---- CodeCompleteConsumer.h - Code Completion Interface ----*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the CodeCompleteConsumer class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_SEMA_CODECOMPLETECONSUMER_H
#define LLVM_CLANG_SEMA_CODECOMPLETECONSUMER_H

#include "clang/AST/Type.h"
#include "clang/AST/CanonicalType.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "clang-c/Index.h"
#include <memory>
#include <string>

namespace llvm {
  class raw_ostream;
}

namespace clang {

class Decl;
  
/// \brief Default priority values for code-completion results based
/// on their kind.
enum {
  /// \brief Priority for the next initialization in a constructor initializer
  /// list.
  CCP_NextInitializer = 7,
  /// \brief Priority for a send-to-super completion.
  CCP_SuperCompletion = 20,
  /// \brief Priority for a declaration that is in the local scope.
  CCP_LocalDeclaration = 34,
  /// \brief Priority for a member declaration found from the current
  /// method or member function.
  CCP_MemberDeclaration = 35,
  /// \brief Priority for a language keyword (that isn't any of the other
  /// categories).
  CCP_Keyword = 40,
  /// \brief Priority for a code pattern.
  CCP_CodePattern = 40,
  /// \brief Priority for a non-type declaration.
  CCP_Declaration = 50,
  /// \brief Priority for a type.
  CCP_Type = CCP_Declaration,
  /// \brief Priority for a constant value (e.g., enumerator).
  CCP_Constant = 65,
  /// \brief Priority for a preprocessor macro.
  CCP_Macro = 70,
  /// \brief Priority for a nested-name-specifier.
  CCP_NestedNameSpecifier = 75,
  /// \brief Priority for a result that isn't likely to be what the user wants,
  /// but is included for completeness.
  CCP_Unlikely = 80,
  
  /// \brief Priority for the Objective-C "_cmd" implicit parameter.
  CCP_ObjC_cmd = CCP_Unlikely
};

/// \brief Priority value deltas that are added to code-completion results
/// based on the context of the result.
enum {
  /// \brief The result is in a base class.
  CCD_InBaseClass = 2,
  /// \brief The result is a C++ non-static member function whose qualifiers
  /// exactly match the object type on which the member function can be called.
  CCD_ObjectQualifierMatch = -1,
  /// \brief The selector of the given message exactly matches the selector
  /// of the current method, which might imply that some kind of delegation
  /// is occurring.
  CCD_SelectorMatch = -3,
  
  /// \brief Adjustment to the "bool" type in Objective-C, where the typedef
  /// "BOOL" is preferred.
  CCD_bool_in_ObjC = 1
};

/// \brief Priority value factors by which we will divide or multiply the
/// priority of a code-completion result.
enum {
  /// \brief Divide by this factor when a code-completion result's type exactly
  /// matches the type we expect.
  CCF_ExactTypeMatch = 4,
  /// \brief Divide by this factor when a code-completion result's type is
  /// similar to the type we expect (e.g., both arithmetic types, both
  /// Objective-C object pointer types).
  CCF_SimilarTypeMatch = 2
};

/// \brief A simplified classification of types used when determining
/// "similar" types for code completion.
enum SimplifiedTypeClass {
  STC_Arithmetic,
  STC_Array,
  STC_Block,
  STC_Function,
  STC_ObjectiveC,
  STC_Other,
  STC_Pointer,
  STC_Record,
  STC_Void
};
  
/// \brief Determine the simplified type class of the given canonical type.
SimplifiedTypeClass getSimplifiedTypeClass(CanQualType T);
  
/// \brief Determine the type that this declaration will have if it is used
/// as a type or in an expression.
QualType getDeclUsageType(ASTContext &C, NamedDecl *ND);
  
/// \brief Determine the priority to be given to a macro code completion result
/// with the given name.
///
/// \param MacroName The name of the macro.
///
/// \param LangOpts Options describing the current language dialect.
///
/// \param PreferredTypeIsPointer Whether the preferred type for the context
/// of this macro is a pointer type.
unsigned getMacroUsagePriority(llvm::StringRef MacroName, 
                               const LangOptions &LangOpts,
                               bool PreferredTypeIsPointer = false);

/// \brief Determine the libclang cursor kind associated with the given
/// declaration.
CXCursorKind getCursorKindForDecl(Decl *D);
  
class FunctionDecl;
class FunctionType;
class FunctionTemplateDecl;
class IdentifierInfo;
class NamedDecl;
class NestedNameSpecifier;
class Sema;

/// \brief The context in which code completion occurred, so that the
/// code-completion consumer can process the results accordingly.
class CodeCompletionContext {
public:
  enum Kind {
    /// \brief An unspecified code-completion context, where the 
    CCC_Other,
    /// \brief Code completion occurred within a "top-level" completion context,
    /// e.g., at namespace or global scope.
    CCC_TopLevel,
    /// \brief Code completion occurred within an Objective-C interface,
    /// protocol, or category interface.
    CCC_ObjCInterface,
    /// \brief Code completion occurred within an Objective-C implementation
    /// or category implementation.
    CCC_ObjCImplementation,
    /// \brief Code completion occurred within the instance variable list of
    /// an Objective-C interface, implementation, or category implementation.
    CCC_ObjCIvarList,
    /// \brief Code completion occurred within a class, struct, or union.
    CCC_ClassStructUnion,
    /// \brief Code completion occurred where a statement (or declaration) is
    /// expected in a function, method, or block.
    CCC_Statement,
    /// \brief Code completion occurred where an expression is expected.
    CCC_Expression,
    /// \brief Code completion occurred where an Objective-C message receiver
    /// is expected.
    CCC_ObjCMessageReceiver,
    /// \brief Code completion occurred on the right-hand side of a member
    /// access expression.
    ///
    /// The results of this completion are the members of the type being 
    /// accessed. The type itself is available via 
    /// \c CodeCompletionContext::getType().
    CCC_MemberAccess,
    /// \brief Code completion occurred after the "enum" keyword, to indicate
    /// an enumeration name.
    CCC_EnumTag,
    /// \brief Code completion occurred after the "union" keyword, to indicate
    /// a union name.
    CCC_UnionTag,
    /// \brief Code completion occurred after the "struct" or "class" keyword,
    /// to indicate a struct or class name.
    CCC_ClassOrStructTag,
    /// \brief Code completion occurred where a protocol name is expected.
    CCC_ObjCProtocolName,
    /// \brief Code completion occurred where a namespace or namespace alias
    /// is expected.
    CCC_Namespace,
    /// \brief Code completion occurred where a type name is expected.
    CCC_Type,
    /// \brief Code completion occurred where a new name is expected.
    CCC_Name,
    /// \brief Code completion occurred where a new name is expected and a
    /// qualified name is permissible.
    CCC_PotentiallyQualifiedName,
    /// \brief Code completion occurred where an macro is being defined.
    CCC_MacroName,
    /// \brief Code completion occurred where a macro name is expected
    /// (without any arguments, in the case of a function-like macro).
    CCC_MacroNameUse,
    /// \brief Code completion occurred within a preprocessor expression.
    CCC_PreprocessorExpression,
    /// \brief Code completion occurred where a preprocessor directive is 
    /// expected.
    CCC_PreprocessorDirective,
    /// \brief Code completion occurred in a context where natural language is
    /// expected, e.g., a comment or string literal.
    ///
    /// This context usually implies that no completions should be added,
    /// unless they come from an appropriate natural-language dictionary.
    CCC_NaturalLanguage,
    /// \brief Code completion for a selector, as in an @selector expression.
    CCC_SelectorName,
    /// \brief Code completion within a type-qualifier list.
    CCC_TypeQualifiers,
    /// \brief Code completion in a parenthesized expression, which means that
    /// we may also have types here in C and Objective-C (as well as in C++).
    CCC_ParenthesizedExpression,
    /// \brief An unknown context, in which we are recovering from a parsing 
    /// error and don't know which completions we should give.
    CCC_Recovery
  };

private:
  enum Kind Kind;

  /// \brief The type that would prefer to see at this point (e.g., the type
  /// of an initializer or function parameter).
  QualType PreferredType;
  
  /// \brief The type of the base object in a member access expression.
  QualType BaseType;
  
public:
  /// \brief Construct a new code-completion context of the given kind.
  CodeCompletionContext(enum Kind Kind) : Kind(Kind) { }
  
  /// \brief Construct a new code-completion context of the given kind.
  CodeCompletionContext(enum Kind Kind, QualType T) : Kind(Kind) { 
    if (Kind == CCC_MemberAccess)
      BaseType = T;
    else
      PreferredType = T;
  }
  
  /// \brief Retrieve the kind of code-completion context.
  enum Kind getKind() const { return Kind; }
  
  /// \brief Retrieve the type that this expression would prefer to have, e.g.,
  /// if the expression is a variable initializer or a function argument, the
  /// type of the corresponding variable or function parameter.
  QualType getPreferredType() const { return PreferredType; }
  
  /// \brief Retrieve the type of the base object in a member-access 
  /// expression.
  QualType getBaseType() const { return BaseType; }

  /// \brief Determines whether we want C++ constructors as results within this
  /// context.
  bool wantConstructorResults() const;
};


/// \brief A "string" used to describe how code completion can
/// be performed for an entity.
///
/// A code completion string typically shows how a particular entity can be 
/// used. For example, the code completion string for a function would show
/// the syntax to call it, including the parentheses, placeholders for the 
/// arguments, etc.  
class CodeCompletionString {
public:
  /// \brief The different kinds of "chunks" that can occur within a code
  /// completion string.
  enum ChunkKind {
    /// \brief The piece of text that the user is expected to type to
    /// match the code-completion string, typically a keyword or the name of a
    /// declarator or macro.</