| //===- ComputeReplacements.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 "clang/Tooling/Core/Replacement.h" |
| #include "clang/Tooling/Syntax/Mutations.h" |
| #include "clang/Tooling/Syntax/Tokens.h" |
| #include "llvm/Support/Error.h" |
| |
| using namespace clang; |
| |
| namespace { |
| using ProcessTokensFn = llvm::function_ref<void(llvm::ArrayRef<syntax::Token>, |
| bool /*IsOriginal*/)>; |
| /// Enumerates spans of tokens from the tree consecutively laid out in memory. |
| void enumerateTokenSpans(const syntax::Tree *Root, ProcessTokensFn Callback) { |
| struct Enumerator { |
| Enumerator(ProcessTokensFn Callback) |
| : SpanBegin(nullptr), SpanEnd(nullptr), SpanIsOriginal(false), |
| Callback(Callback) {} |
| |
| void run(const syntax::Tree *Root) { |
| process(Root); |
| // Report the last span to the user. |
| if (SpanBegin) |
| Callback(llvm::makeArrayRef(SpanBegin, SpanEnd), SpanIsOriginal); |
| } |
| |
| private: |
| void process(const syntax::Node *N) { |
| if (auto *T = dyn_cast<syntax::Tree>(N)) { |
| for (const auto *C = T->getFirstChild(); C != nullptr; |
| C = C->getNextSibling()) |
| process(C); |
| return; |
| } |
| |
| auto *L = cast<syntax::Leaf>(N); |
| if (SpanEnd == L->getToken() && SpanIsOriginal == L->isOriginal()) { |
| // Extend the current span. |
| ++SpanEnd; |
| return; |
| } |
| // Report the current span to the user. |
| if (SpanBegin) |
| Callback(llvm::makeArrayRef(SpanBegin, SpanEnd), SpanIsOriginal); |
| // Start recording a new span. |
| SpanBegin = L->getToken(); |
| SpanEnd = SpanBegin + 1; |
| SpanIsOriginal = L->isOriginal(); |
| } |
| |
| const syntax::Token *SpanBegin; |
| const syntax::Token *SpanEnd; |
| bool SpanIsOriginal; |
| ProcessTokensFn Callback; |
| }; |
| |
| return Enumerator(Callback).run(Root); |
| } |
| |
| syntax::FileRange rangeOfExpanded(const syntax::Arena &A, |
| llvm::ArrayRef<syntax::Token> Expanded) { |
| const auto &Buffer = A.getTokenBuffer(); |
| const auto &SM = A.getSourceManager(); |
| |
| // Check that \p Expanded actually points into expanded tokens. |
| assert(Buffer.expandedTokens().begin() <= Expanded.begin()); |
| assert(Expanded.end() < Buffer.expandedTokens().end()); |
| |
| if (Expanded.empty()) |
| // (!) empty tokens must always point before end(). |
| return syntax::FileRange( |
| SM, SM.getExpansionLoc(Expanded.begin()->location()), /*Length=*/0); |
| |
| auto Spelled = Buffer.spelledForExpanded(Expanded); |
| assert(Spelled && "could not find spelled tokens for expanded"); |
| return syntax::Token::range(SM, Spelled->front(), Spelled->back()); |
| } |
| } // namespace |
| |
| tooling::Replacements |
| syntax::computeReplacements(const syntax::Arena &A, |
| const syntax::TranslationUnit &TU) { |
| const auto &Buffer = A.getTokenBuffer(); |
| const auto &SM = A.getSourceManager(); |
| |
| tooling::Replacements Replacements; |
| // Text inserted by the replacement we are building now. |
| std::string Replacement; |
| auto emitReplacement = [&](llvm::ArrayRef<syntax::Token> ReplacedRange) { |
| if (ReplacedRange.empty() && Replacement.empty()) |
| return; |
| llvm::cantFail(Replacements.add(tooling::Replacement( |
| SM, rangeOfExpanded(A, ReplacedRange).toCharRange(SM), Replacement))); |
| Replacement = ""; |
| }; |
| |
| const syntax::Token *NextOriginal = Buffer.expandedTokens().begin(); |
| enumerateTokenSpans( |
| &TU, [&](llvm::ArrayRef<syntax::Token> Tokens, bool IsOriginal) { |
| if (!IsOriginal) { |
| Replacement += |
| syntax::Token::range(SM, Tokens.front(), Tokens.back()).text(SM); |
| return; |
| } |
| assert(NextOriginal <= Tokens.begin()); |
| // We are looking at a span of original tokens. |
| if (NextOriginal != Tokens.begin()) { |
| // There is a gap, record a replacement or deletion. |
| emitReplacement(llvm::makeArrayRef(NextOriginal, Tokens.begin())); |
| } else { |
| // No gap, but we may have pending insertions. Emit them now. |
| emitReplacement(llvm::makeArrayRef(NextOriginal, /*Length=*/0)); |
| } |
| NextOriginal = Tokens.end(); |
| }); |
| |
| // We might have pending replacements at the end of file. If so, emit them. |
| emitReplacement(llvm::makeArrayRef( |
| NextOriginal, Buffer.expandedTokens().drop_back().end())); |
| |
| return Replacements; |
| } |