forked from OSchip/llvm-project
99 lines
3.6 KiB
C++
99 lines
3.6 KiB
C++
//===--- SwapIfBranches.cpp --------------------------------------*- C++-*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "Logger.h"
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#include "ParsedAST.h"
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#include "SourceCode.h"
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#include "refactor/Tweak.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/RecursiveASTVisitor.h"
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#include "clang/AST/Stmt.h"
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#include "clang/Basic/LangOptions.h"
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#include "clang/Basic/SourceLocation.h"
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#include "clang/Basic/SourceManager.h"
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#include "clang/Lex/Lexer.h"
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#include "clang/Tooling/Core/Replacement.h"
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#include "llvm/ADT/None.h"
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#include "llvm/ADT/Optional.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/Error.h"
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namespace clang {
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namespace clangd {
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namespace {
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/// Swaps the 'then' and 'else' branch of the if statement.
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/// Before:
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/// if (foo) { return 10; } else { continue; }
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/// ^^^^^^^ ^^^^
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/// After:
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/// if (foo) { continue; } else { return 10; }
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class SwapIfBranches : public Tweak {
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public:
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const char *id() const override final;
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bool prepare(const Selection &Inputs) override;
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Expected<Effect> apply(const Selection &Inputs) override;
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std::string title() const override { return "Swap if branches"; }
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Intent intent() const override { return Refactor; }
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private:
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const IfStmt *If = nullptr;
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};
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REGISTER_TWEAK(SwapIfBranches)
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bool SwapIfBranches::prepare(const Selection &Inputs) {
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for (const SelectionTree::Node *N = Inputs.ASTSelection.commonAncestor();
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N && !If; N = N->Parent) {
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// Stop once we hit a block, e.g. a lambda in the if condition.
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if (dyn_cast_or_null<CompoundStmt>(N->ASTNode.get<Stmt>()))
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return false;
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If = dyn_cast_or_null<IfStmt>(N->ASTNode.get<Stmt>());
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}
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// avoid dealing with single-statement brances, they require careful handling
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// to avoid changing semantics of the code (i.e. dangling else).
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return If && dyn_cast_or_null<CompoundStmt>(If->getThen()) &&
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dyn_cast_or_null<CompoundStmt>(If->getElse());
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}
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Expected<Tweak::Effect> SwapIfBranches::apply(const Selection &Inputs) {
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auto &Ctx = Inputs.AST->getASTContext();
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auto &SrcMgr = Inputs.AST->getSourceManager();
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auto ThenRng = toHalfOpenFileRange(SrcMgr, Ctx.getLangOpts(),
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If->getThen()->getSourceRange());
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if (!ThenRng)
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return llvm::createStringError(
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llvm::inconvertibleErrorCode(),
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"Could not obtain range of the 'then' branch. Macros?");
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auto ElseRng = toHalfOpenFileRange(SrcMgr, Ctx.getLangOpts(),
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If->getElse()->getSourceRange());
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if (!ElseRng)
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return llvm::createStringError(
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llvm::inconvertibleErrorCode(),
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"Could not obtain range of the 'else' branch. Macros?");
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auto ThenCode = toSourceCode(SrcMgr, *ThenRng);
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auto ElseCode = toSourceCode(SrcMgr, *ElseRng);
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tooling::Replacements Result;
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if (auto Err = Result.add(tooling::Replacement(Ctx.getSourceManager(),
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ThenRng->getBegin(),
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ThenCode.size(), ElseCode)))
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return std::move(Err);
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if (auto Err = Result.add(tooling::Replacement(Ctx.getSourceManager(),
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ElseRng->getBegin(),
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ElseCode.size(), ThenCode)))
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return std::move(Err);
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return Effect::mainFileEdit(SrcMgr, std::move(Result));
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}
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} // namespace
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} // namespace clangd
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} // namespace clang
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