llvm-for-llvmta/tools/clang/lib/Tooling/Refactoring/Rename/USRFinder.cpp

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5.0 KiB
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//===--- USRFinder.cpp - Clang refactoring library ------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file Implements a recursive AST visitor that finds the USR of a symbol at a
/// point.
///
//===----------------------------------------------------------------------===//
#include "clang/Tooling/Refactoring/Rename/USRFinder.h"
#include "clang/AST/AST.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Index/USRGeneration.h"
#include "clang/Lex/Lexer.h"
#include "clang/Tooling/Refactoring/RecursiveSymbolVisitor.h"
#include "llvm/ADT/SmallVector.h"
using namespace llvm;
namespace clang {
namespace tooling {
namespace {
/// Recursively visits each AST node to find the symbol underneath the cursor.
class NamedDeclOccurrenceFindingVisitor
: public RecursiveSymbolVisitor<NamedDeclOccurrenceFindingVisitor> {
public:
// Finds the NamedDecl at a point in the source.
// \param Point the location in the source to search for the NamedDecl.
explicit NamedDeclOccurrenceFindingVisitor(const SourceLocation Point,
const ASTContext &Context)
: RecursiveSymbolVisitor(Context.getSourceManager(),
Context.getLangOpts()),
Point(Point), Context(Context) {}
bool visitSymbolOccurrence(const NamedDecl *ND,
ArrayRef<SourceRange> NameRanges) {
if (!ND)
return true;
for (const auto &Range : NameRanges) {
SourceLocation Start = Range.getBegin();
SourceLocation End = Range.getEnd();
if (!Start.isValid() || !Start.isFileID() || !End.isValid() ||
!End.isFileID() || !isPointWithin(Start, End))
return true;
}
Result = ND;
return false;
}
const NamedDecl *getNamedDecl() const { return Result; }
private:
// Determines if the Point is within Start and End.
bool isPointWithin(const SourceLocation Start, const SourceLocation End) {
// FIXME: Add tests for Point == End.
return Point == Start || Point == End ||
(Context.getSourceManager().isBeforeInTranslationUnit(Start,
Point) &&
Context.getSourceManager().isBeforeInTranslationUnit(Point, End));
}
const NamedDecl *Result = nullptr;
const SourceLocation Point; // The location to find the NamedDecl.
const ASTContext &Context;
};
} // end anonymous namespace
const NamedDecl *getNamedDeclAt(const ASTContext &Context,
const SourceLocation Point) {
const SourceManager &SM = Context.getSourceManager();
NamedDeclOccurrenceFindingVisitor Visitor(Point, Context);
// Try to be clever about pruning down the number of top-level declarations we
// see. If both start and end is either before or after the point we're
// looking for the point cannot be inside of this decl. Don't even look at it.
for (auto *CurrDecl : Context.getTranslationUnitDecl()->decls()) {
SourceLocation StartLoc = CurrDecl->getBeginLoc();
SourceLocation EndLoc = CurrDecl->getEndLoc();
if (StartLoc.isValid() && EndLoc.isValid() &&
SM.isBeforeInTranslationUnit(StartLoc, Point) !=
SM.isBeforeInTranslationUnit(EndLoc, Point))
Visitor.TraverseDecl(CurrDecl);
}
return Visitor.getNamedDecl();
}
namespace {
/// Recursively visits each NamedDecl node to find the declaration with a
/// specific name.
class NamedDeclFindingVisitor
: public RecursiveASTVisitor<NamedDeclFindingVisitor> {
public:
explicit NamedDeclFindingVisitor(StringRef Name) : Name(Name) {}
// We don't have to traverse the uses to find some declaration with a
// specific name, so just visit the named declarations.
bool VisitNamedDecl(const NamedDecl *ND) {
if (!ND)
return true;
// Fully qualified name is used to find the declaration.
if (Name != ND->getQualifiedNameAsString() &&
Name != "::" + ND->getQualifiedNameAsString())
return true;
Result = ND;
return false;
}
const NamedDecl *getNamedDecl() const { return Result; }
private:
const NamedDecl *Result = nullptr;
StringRef Name;
};
} // end anonymous namespace
const NamedDecl *getNamedDeclFor(const ASTContext &Context,
const std::string &Name) {
NamedDeclFindingVisitor Visitor(Name);
Visitor.TraverseDecl(Context.getTranslationUnitDecl());
return Visitor.getNamedDecl();
}
std::string getUSRForDecl(const Decl *Decl) {
llvm::SmallString<128> Buff;
// FIXME: Add test for the nullptr case.
if (Decl == nullptr || index::generateUSRForDecl(Decl, Buff))
return "";
return std::string(Buff);
}
} // end namespace tooling
} // end namespace clang