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swift-mirror/lib/Parse/Scope.cpp

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//===--- Scope.cpp - Scope Implementation ---------------------------------===//
//
// 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 semantic analysis for Swift declarations.
//
//===----------------------------------------------------------------------===//
#include "swift/AST/Attr.h"
#include "Scope.h"
#include "Parser.h"
#include "llvm/ADT/Twine.h"
using namespace swift;
//===----------------------------------------------------------------------===//
// Scope Implementation
//===----------------------------------------------------------------------===//
Scope::Scope(Parser *P) : SI(P->ScopeInfo), ValueHTScope(SI.ValueScopeHT),
PrevScope(SI.CurScope) {
if (SI.CurScope)
Depth = SI.CurScope->Depth+1;
else
Depth = 0;
SI.CurScope = this;
}
//===----------------------------------------------------------------------===//
// ScopeInfo Implementation
//===----------------------------------------------------------------------===//
static void diagnoseRedefinition(ValueDecl *Prev, ValueDecl *New, Parser &P) {
assert(New != Prev && "Cannot conflict with self");
P.diagnose(New->getLocStart(), diag::decl_redefinition, New->isDefinition());
P.diagnose(Prev->getLocStart(), diag::previous_decldef, Prev->isDefinition(),
Prev->getName());
}
/// checkValidOverload - Check whether it is ok for D1 and D2 to be declared at
/// the same scope. This check is a transitive relationship, so if "D1 is a
/// valid overload of D2" and "D2 is a valid overload of D3" then we know that
/// D1/D3 are valid overloads and we don't have to check all permutations.
static bool checkValidOverload(const ValueDecl *D1, const ValueDecl *D2,
Parser &P) {
if (D1->getAttrs().isInfix() && D2->getAttrs().isInfix() &&
D1->getAttrs().getInfixData() != D2->getAttrs().getInfixData()) {
P.diagnose(D1->getLocStart(), diag::precedence_overload);
// FIXME: Pass identifier through, when the diagnostics system can handle
// it.
P.diagnose(D2->getLocStart(), diag::previous_declaration, D2->getName());
return true;
}
// Otherwise, everything is fine.
return false;
}
/// addToScope - Register the specified decl as being in the current lexical
/// scope.
void ScopeInfo::addToScope(ValueDecl *D) {
// If we have a shadowed variable definition, check to see if we have a
// redefinition: two definitions in the same scope with the same name.
ValueScopeHTTy::iterator EntryI = ValueScopeHT.begin(D->getName());
// A redefinition is a hit in the scoped table at the same depth.
if (EntryI != ValueScopeHT.end() && EntryI->first == CurScope->getDepth()) {
ValueDecl *PrevDecl = EntryI->second;
// If this is at top-level scope, we allow overloading. If not, we don't.
// FIXME: This should be tied to whether the scope corresponds to a
// DeclContext like a TranslationUnit or a Namespace. Add a bit to Scope
// to track this?
if (CurScope->getDepth() != 0)
return diagnoseRedefinition(PrevDecl, D, TheParser);
// If this is at top-level scope, validate that the members of the overload
// set all agree.
// Check to see if D and PrevDecl are valid in the same overload set.
if (checkValidOverload(D, PrevDecl, TheParser))
return;
// Note: we don't check whether all of the elements of the overload set have
// different argument types. This is checked later.
}
ValueScopeHT.insert(D->getName(), std::make_pair(CurScope->getDepth(), D));
}