Files
swift-mirror/lib/Refactoring/CollapseNestedIfStmt.cpp

85 lines
2.5 KiB
C++

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "RefactoringActions.h"
#include "swift/AST/Stmt.h"
using namespace swift::refactoring;
static std::pair<IfStmt *, IfStmt *>
findCollapseNestedIfTarget(ResolvedCursorInfoPtr CursorInfo) {
auto StmtStartInfo = dyn_cast<ResolvedStmtStartCursorInfo>(CursorInfo);
if (!StmtStartInfo)
return {};
// Ensure the statement is 'if' statement. It must not have 'else' clause.
IfStmt *OuterIf = dyn_cast<IfStmt>(StmtStartInfo->getTrailingStmt());
if (!OuterIf)
return {};
if (OuterIf->getElseStmt())
return {};
// The body must contain a sole inner 'if' statement.
auto Body = dyn_cast_or_null<BraceStmt>(OuterIf->getThenStmt());
if (!Body || Body->getNumElements() != 1)
return {};
IfStmt *InnerIf =
dyn_cast_or_null<IfStmt>(Body->getFirstElement().dyn_cast<Stmt *>());
if (!InnerIf)
return {};
// Inner 'if' statement also cannot have 'else' clause.
if (InnerIf->getElseStmt())
return {};
return {OuterIf, InnerIf};
}
bool RefactoringActionCollapseNestedIfStmt::isApplicable(
ResolvedCursorInfoPtr CursorInfo, DiagnosticEngine &Diag) {
return findCollapseNestedIfTarget(CursorInfo).first;
}
bool RefactoringActionCollapseNestedIfStmt::performChange() {
auto Target = findCollapseNestedIfTarget(CursorInfo);
if (!Target.first)
return true;
auto OuterIf = Target.first;
auto InnerIf = Target.second;
EditorConsumerInsertStream OS(
EditConsumer, SM,
Lexer::getCharSourceRangeFromSourceRange(SM, OuterIf->getSourceRange()));
OS << tok::kw_if << " ";
// Emit conditions.
bool first = true;
for (auto &C : llvm::concat<StmtConditionElement>(OuterIf->getCond(),
InnerIf->getCond())) {
if (first)
first = false;
else
OS << ", ";
OS << Lexer::getCharSourceRangeFromSourceRange(SM, C.getSourceRange())
.str();
}
// Emit body.
OS << " ";
OS << Lexer::getCharSourceRangeFromSourceRange(
SM, InnerIf->getThenStmt()->getSourceRange())
.str();
return false;
}