llvm/clang-tools-extra/clangd/CodeComplete.h

//===--- CodeComplete.h ------------------------------------------*- C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Code completion provides suggestions for what the user might type next.
// After "std::string S; S." we might suggest members of std::string.
// Signature help describes the parameters of a function as you type them.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_CODECOMPLETE_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_CODECOMPLETE_H

#include "ASTSignals.h"
#include "Compiler.h"
#include "Protocol.h"
#include "Quality.h"
#include "index/Index.h"
#include "index/Symbol.h"
#include "index/SymbolOrigin.h"
#include "support/Markup.h"
#include "support/Path.h"
#include "clang/Sema/CodeCompleteConsumer.h"
#include "clang/Sema/CodeCompleteOptions.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include <functional>
#include <future>
#include <optional>
#include <utility>

namespace clang {
class NamedDecl;
namespace clangd {
struct PreambleData;
struct CodeCompletion;

struct CodeCompleteOptions { … };

// Semi-structured representation of a code-complete suggestion for our C++ API.
// We don't use the LSP structures here (unlike most features) as we want
// to expose more data to allow for more precise testing and evaluation.
struct CodeCompletion { … };
raw_ostream &operator<<(raw_ostream &, const CodeCompletion &);
struct CodeCompleteResult { … };
raw_ostream &operator<<(raw_ostream &, const CodeCompleteResult &);

/// A speculative and asynchronous fuzzy find index request (based on cached
/// request) that can be sent before parsing sema. This would reduce completion
/// latency if the speculation succeeds.
struct SpeculativeFuzzyFind { … };

/// Gets code completions at a specified \p Pos in \p FileName.
///
/// If \p Preamble is nullptr, this runs code completion without compiling the
/// code.
///
/// If \p SpecFuzzyFind is set, a speculative and asynchronous fuzzy find index
/// request (based on cached request) will be run before parsing sema. In case
/// the speculative result is used by code completion (e.g. speculation failed),
/// the speculative result is not consumed, and `SpecFuzzyFind` is only
/// destroyed when the async request finishes.
CodeCompleteResult codeComplete(PathRef FileName, Position Pos,
                                const PreambleData *Preamble,
                                const ParseInputs &ParseInput,
                                CodeCompleteOptions Opts,
                                SpeculativeFuzzyFind *SpecFuzzyFind = nullptr);

/// Get signature help at a specified \p Pos in \p FileName.
SignatureHelp signatureHelp(PathRef FileName, Position Pos,
                            const PreambleData &Preamble,
                            const ParseInputs &ParseInput,
                            MarkupKind DocumentationFormat);

// For index-based completion, we only consider:
//   * symbols in namespaces or translation unit scopes (e.g. no class
//     members, no locals)
//   * enum constants (both scoped and unscoped)
//   * primary templates (no specializations)
// For the other cases, we let Clang do the completion because it does not
// need any non-local information and it will be much better at following
// lookup rules. Other symbols still appear in the index for other purposes,
// like workspace/symbols or textDocument/definition, but are not used for code
// completion.
bool isIndexedForCodeCompletion(const NamedDecl &ND, ASTContext &ASTCtx);

// Text immediately before the completion point that should be completed.
// This is heuristically derived from the source code, and is used when:
//   - semantic analysis fails
//   - semantic analysis may be slow, and we speculatively query the index
struct CompletionPrefix { … };
// Heuristically parses before Offset to determine what should be completed.
CompletionPrefix guessCompletionPrefix(llvm::StringRef Content,
                                       unsigned Offset);

// Whether it makes sense to complete at the point based on typed characters.
// For instance, we implicitly trigger at `a->^` but not at `a>^`.
bool allowImplicitCompletion(llvm::StringRef Content, unsigned Offset);

} // namespace clangd
} // namespace clang

#endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_CODECOMPLETE_H