llvm/clang-tools-extra/clangd/InlayHints.cpp

//===--- InlayHints.cpp ------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
#include "InlayHints.h"
#include "../clang-tidy/utils/DesignatedInitializers.h"
#include "AST.h"
#include "Config.h"
#include "HeuristicResolver.h"
#include "ParsedAST.h"
#include "SourceCode.h"
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclarationName.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/Type.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/raw_ostream.h"
#include <optional>
#include <string>

namespace clang {
namespace clangd {
namespace {

// For now, inlay hints are always anchored at the left or right of their range.
enum class HintSide { … };

void stripLeadingUnderscores(StringRef &Name) { … }

// getDeclForType() returns the decl responsible for Type's spelling.
// This is the inverse of ASTContext::getTypeDeclType().
template <typename Ty, typename = decltype(((Ty *)nullptr)->getDecl())>
const NamedDecl *getDeclForTypeImpl(const Ty *T) { … }
const NamedDecl *getDeclForTypeImpl(const void *T) { … }
const NamedDecl *getDeclForType(const Type *T) { … }

// getSimpleName() returns the plain identifier for an entity, if any.
llvm::StringRef getSimpleName(const DeclarationName &DN) { … }
llvm::StringRef getSimpleName(const NamedDecl &D) { … }
llvm::StringRef getSimpleName(QualType T) { … }

// Returns a very abbreviated form of an expression, or "" if it's too complex.
// For example: `foo->bar()` would produce "bar".
// This is used to summarize e.g. the condition of a while loop.
std::string summarizeExpr(const Expr *E) { … }

// Determines if any intermediate type in desugaring QualType QT is of
// substituted template parameter type. Ignore pointer or reference wrappers.
bool isSugaredTemplateParameter(QualType QT) { … }

// A simple wrapper for `clang::desugarForDiagnostic` that provides optional
// semantic.
std::optional<QualType> desugar(ASTContext &AST, QualType QT) { … }

// Apply a series of heuristic methods to determine whether or not a QualType QT
// is suitable for desugaring (e.g. getting the real name behind the using-alias
// name). If so, return the desugared type. Otherwise, return the unchanged
// parameter QT.
//
// This could be refined further. See
// https://github.com/clangd/clangd/issues/1298.
QualType maybeDesugar(ASTContext &AST, QualType QT) { … }

// Given a callee expression `Fn`, if the call is through a function pointer,
// try to find the declaration of the corresponding function pointer type,
// so that we can recover argument names from it.
// FIXME: This function is mostly duplicated in SemaCodeComplete.cpp; unify.
static FunctionProtoTypeLoc getPrototypeLoc(Expr *Fn) { … }

ArrayRef<const ParmVarDecl *>
maybeDropCxxExplicitObjectParameters(ArrayRef<const ParmVarDecl *> Params) { … }

struct Callee { … };

class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> { … };

} // namespace

std::vector<InlayHint> inlayHints(ParsedAST &AST,
                                  std::optional<Range> RestrictRange) { … }

} // namespace clangd
} // namespace clang