Files
swift-mirror/lib/Sema/MiscDiagnostics.cpp
Anna Zaks f8a79a56fb Address the reviews for r9982
Swift SVN r9999
2013-11-06 19:46:20 +00:00

113 lines
3.6 KiB
C++

//===--- MiscDiagnostics.cpp - AST-Level Diagnostics ----------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements AST-level diagnostics.
//
//===----------------------------------------------------------------------===//
#include "MiscDiagnostics.h"
#include "TypeChecker.h"
#include "swift/Basic/SourceManager.h"
using namespace swift;
//===--------------------------------------------------------------------===//
// Diagnose assigning variable to itself.
//===--------------------------------------------------------------------===//
static Decl *findSimpleReferencedDecl(const Expr *E) {
if (auto *LE = dyn_cast<LoadExpr>(E))
E = LE->getSubExpr();
if (auto *DRE = dyn_cast<DeclRefExpr>(E))
return DRE->getDecl();
return nullptr;
}
static std::pair<Decl *, Decl *> findReferencedDecl(const Expr *E) {
if (auto *LE = dyn_cast<LoadExpr>(E))
E = LE->getSubExpr();
if (auto *D = findSimpleReferencedDecl(E))
return std::make_pair(nullptr, D);
if (auto *MRE = dyn_cast<MemberRefExpr>(E)) {
return std::make_pair(findSimpleReferencedDecl(MRE->getBase()),
MRE->getMember().getDecl());
}
return std::make_pair(nullptr, nullptr);
}
static void diagSelfAssignment(TypeChecker &TC, const Expr *E) {
auto *AE = dyn_cast<AssignExpr>(E);
if (!AE)
return;
auto LHSDecl = findReferencedDecl(AE->getDest());
auto RHSDecl = findReferencedDecl(AE->getSrc());
if (LHSDecl.second && LHSDecl == RHSDecl) {
TC.diagnose(AE->getLoc(), LHSDecl.first ? diag::self_assignment_prop
: diag::self_assignment_var)
.highlight(AE->getDest()->getSourceRange())
.highlight(AE->getSrc()->getSourceRange());
}
}
//===--------------------------------------------------------------------===//
// Diagnose unreachable code.
//===--------------------------------------------------------------------===//
/// Issue a warning on code containing retrun expression on a differnt line than
/// the return keyword and both have the same indentation:
/// ...
/// return
/// foo()
static void diagUnreachableCode(TypeChecker &TC, const Stmt *S) {
auto *RS = dyn_cast<ReturnStmt>(S);
if (!RS)
return;
if (!RS->hasResult())
return;
auto RetExpr = RS->getResult();
auto RSLoc = RS->getStartLoc();
auto RetExprLoc = RetExpr->getStartLoc();
// FIXME: Expose getColumnNumber() in LLVM SourceMgr to make this check
// cheaper.
if (RSLoc.isInvalid() || RetExprLoc.isInvalid() || (RSLoc == RetExprLoc))
return;
SourceManager &SM = TC.Context.SourceMgr;
if (SM.getLineAndColumn(RSLoc).second ==
SM.getLineAndColumn(RetExprLoc).second) {
TC.diagnose(RetExpr->getStartLoc(), diag::unindented_code_after_return);
TC.diagnose(RetExpr->getStartLoc(), diag::indent_expression_to_silence);
return;
}
return;
}
//===--------------------------------------------------------------------===//
// High-level entry points.
//===--------------------------------------------------------------------===//
void swift::performExprDiagnostics(TypeChecker &TC, const Expr *E) {
diagSelfAssignment(TC, E);
}
void swift::performStmtDiagnostics(TypeChecker &TC, const Stmt *S) {
return diagUnreachableCode(TC, S);
}