ASTScope.cpp

//===--- ASTScopeImpl.cpp - Swift Object-Oriented AST Scope ---------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// This file implements the common functions of the 49 ontology.
///
//===----------------------------------------------------------------------===//
#include "swift/AST/ASTScope.h"

#include "swift/AST/ASTContext.h"
#include "swift/AST/ASTWalker.h"
#include "swift/Bridging/ASTGen.h"
#include "swift/AST/Decl.h"
#include "swift/AST/Expr.h"
#include "swift/AST/Initializer.h"
#include "swift/AST/LazyResolver.h"
#include "swift/AST/Module.h"
#include "swift/AST/NameLookup.h"
#include "swift/AST/ParameterList.h"
#include "swift/AST/Pattern.h"
#include "swift/AST/SourceFile.h"
#include "swift/AST/Stmt.h"
#include "swift/AST/TypeRepr.h"
#include "swift/Basic/Assertions.h"
#include "swift/Basic/NullablePtr.h"
#include "swift/Basic/STLExtras.h"
#include "llvm/Support/Compiler.h"
#include <algorithm>

using namespace swift;
using namespace ast_scope;

#pragma mark ASTScope

class LoggingASTScopeDeclConsumer
    : public namelookup::AbstractASTScopeDeclConsumer {
private:
  const int shouldLookInMembers = 0b10;
  namelookup::AbstractASTScopeDeclConsumer *originalConsumer;

public:
  mutable SmallVector<BridgedConsumedLookupResult> recordedElements;

  LoggingASTScopeDeclConsumer(
      namelookup::AbstractASTScopeDeclConsumer *consumer)
      : originalConsumer(consumer) {}

  ~LoggingASTScopeDeclConsumer() = default;

  /// Called for every ValueDecl visible from the lookup.
  ///
  /// Takes an array in order to batch the consumption before setting
  /// IndexOfFirstOuterResult when necessary.
  ///
  /// Additionally, each name is logged to `recordedElements` and
  /// can be later used in validation of `SwiftLexicalLookup` result.
  ///
  /// \param baseDC either a type context or the local context of a
  /// `self` parameter declaration. See LookupResult for a discussion
  /// of type -vs- instance lookup results.
  ///
  /// \return true if the lookup should be stopped at this point.
  bool consume(ArrayRef<ValueDecl *> values,
               NullablePtr<DeclContext> baseDC = nullptr) override {
    bool endOfLookup = originalConsumer->consume(values, baseDC);

    for (auto value : values) {
      if (auto sourceLoc = value->getLoc()) {
        recordedElements.push_back(BridgedConsumedLookupResult(
            value->getBaseIdentifier(), sourceLoc, endOfLookup));
      } else {
        // If sourceLoc is unavailable, use location of it's parent.
        recordedElements.push_back(BridgedConsumedLookupResult(
            value->getBaseIdentifier(),
            value->getDeclContext()->getAsDecl()->getLoc(), endOfLookup));
      }
    }

    return endOfLookup;
  };

  /// Look for members of a nominal type or extension scope.
  ///
  /// Each call is recorded in `recordedElements` with a special flag set.
  /// It can be later used in validation of `SwiftLexicalLookup` result.
  ///
  /// \return true if the lookup should be stopped at this point.
  bool lookInMembers(const DeclContext *scopeDC) const override {
    bool endOfLookup = originalConsumer->lookInMembers(scopeDC);

    if (auto *extDecl = dyn_cast<ExtensionDecl>(scopeDC)) {
      recordedElements.push_back(BridgedConsumedLookupResult(
          Identifier(), extDecl->getExtendedTypeRepr()->getLoc(),
          shouldLookInMembers + endOfLookup));
    } else {
      recordedElements.push_back(BridgedConsumedLookupResult(
          scopeDC->getSelfNominalTypeDecl()->getBaseIdentifier(),
          scopeDC->getAsDecl()->getLoc(), shouldLookInMembers + endOfLookup));
    }

    return endOfLookup;
  };

  /// Called for local VarDecls that might not yet be in scope.
  ///
  /// Note that the set of VarDecls visited here are going to be a
  /// superset of those visited in consume().
  bool consumePossiblyNotInScope(ArrayRef<VarDecl *> values) override {
    bool result = originalConsumer->consumePossiblyNotInScope(values);
    return result;
  }

  /// Called right before looking at the parent scope of a BraceStmt.
  ///
  /// \return true if the lookup should be stopped at this point.
  bool finishLookupInBraceStmt(BraceStmt *stmt) override {
    return originalConsumer->finishLookupInBraceStmt(stmt);
  }

#ifndef NDEBUG
  void startingNextLookupStep() override {
    originalConsumer->startingNextLookupStep();
  }
  void finishingLookup(std::string input) const override {
    originalConsumer->finishingLookup(input);
  }
  bool isTargetLookup() const override {
    return originalConsumer->isTargetLookup();
  }
#endif
};

void ASTScope::unqualifiedLookup(
    SourceFile *SF, SourceLoc loc,
    namelookup::AbstractASTScopeDeclConsumer &consumer) {
  if (loc.isValid()) {
    SF = SF->getParentModule()->getSourceFileContainingLocation(loc);
  }

  if (auto *s = SF->getASTContext().Stats)
    ++s->getFrontendCounters().NumASTScopeLookups;

  // Perform validation of SwiftLexicalLookup if option
  // Feature::UnqualifiedLookupValidation is enabled and lookup was not
  // performed in a macro.
  if (SF->getASTContext().LangOpts.hasFeature(
          Feature::UnqualifiedLookupValidation) &&
      !SF->getEnclosingSourceFile()) {
    LoggingASTScopeDeclConsumer loggingASTScopeDeclConsumer =
        LoggingASTScopeDeclConsumer(&consumer);

    ASTScopeImpl::unqualifiedLookup(SF, loc, loggingASTScopeDeclConsumer);

    bool passed = swift_ASTGen_validateUnqualifiedLookup(
        SF->getExportedSourceFile(), SF->getASTContext(), loc,
        loggingASTScopeDeclConsumer.finishLookupInBraceStmt(nullptr),
        BridgedArrayRef(loggingASTScopeDeclConsumer.recordedElements.data(),
                        loggingASTScopeDeclConsumer.recordedElements.size()));

    if (!passed) {
      SF->getASTContext().Diags.diagnose(loc, diag::lookup_outputs_dont_match);
    }
  } else {
    ASTScopeImpl::unqualifiedLookup(SF, loc, consumer);
  }
}

llvm::SmallVector<LabeledStmt *, 4> ASTScope::lookupLabeledStmts(
    SourceFile *sourceFile, SourceLoc loc) {
  return ASTScopeImpl::lookupLabeledStmts(sourceFile, loc);
}

std::pair<CaseStmt *, CaseStmt *> ASTScope::lookupFallthroughSourceAndDest(
    SourceFile *sourceFile, SourceLoc loc) {
  return ASTScopeImpl::lookupFallthroughSourceAndDest(sourceFile, loc);
}

void ASTScope::lookupEnclosingMacroScope(
    SourceFile *sourceFile, SourceLoc loc,
    llvm::function_ref<bool(PotentialMacro)> body) {
  return ASTScopeImpl::lookupEnclosingMacroScope(sourceFile, loc, body);
}

ABIAttr *ASTScope::lookupEnclosingABIAttributeScope(
    SourceFile *sourceFile, SourceLoc loc) {
  return ASTScopeImpl::lookupEnclosingABIAttributeScope(sourceFile, loc);
}

CatchNode ASTScope::lookupCatchNode(ModuleDecl *module, SourceLoc loc) {
  return ASTScopeImpl::lookupCatchNode(module, loc);
}

#if SWIFT_COMPILER_IS_MSVC
#pragma warning(supress: 4996)
#endif

void ASTScope::dump() const { impl->dump(); }

void ASTScope::print(llvm::raw_ostream &out) const { impl->print(out); }
void ASTScope::dumpOneScopeMapLocation(std::pair<unsigned, unsigned> lineCol) {
  impl->dumpOneScopeMapLocation(lineCol);
}

#pragma mark ASTScopeImpl


const PatternBindingEntry &AbstractPatternEntryScope::getPatternEntry() const {
  return decl->getPatternList()[patternEntryIndex];
}

Pattern *AbstractPatternEntryScope::getPattern() const {
  return getPatternEntry().getPattern();
}

NullablePtr<AbstractClosureExpr> BraceStmtScope::parentClosureIfAny() const {
  if (auto parent = getParent()) {
    if (auto closureScope = dyn_cast<ClosureParametersScope>(parent.get()))
      return closureScope->closureExpr;
  }

  return nullptr;
}

std::string ASTScopeImpl::getClassName() const {
  // GenericTypeOrExtensionScope provides a custom implementation that deals
  // with declaration names and "portions".
  if (auto generic = dyn_cast<GenericTypeOrExtensionScope>(this))
    return generic->getClassName();

  switch (getKind()) {
#define SCOPE_NODE(Name) case ScopeKind::Name: return #Name "Scope";
#include "swift/AST/ASTScopeNodes.def"
  }
}

std::string GenericTypeOrExtensionScope::getClassName() const {
  return declKindName() + portionName() + "Scope";
}

NullablePtr<Decl> ASTScopeImpl::getDeclIfAny() const {
  switch (getKind()) {
    // Declaration scope nodes extract the decl directly.
#define DECL_SCOPE_NODE(Name) \
    case ScopeKind::Name: return cast<Name##Scope>(this)->getDecl();
#define SCOPE_NODE(Name)
#include "swift/AST/ASTScopeNodes.def"

    // Everything else returns nullptr.
#define DECL_SCOPE_NODE(Name)
#define SCOPE_NODE(Name) case ScopeKind::Name:
#include "swift/AST/ASTScopeNodes.def"
      return nullptr;
  }
}

NullablePtr<Stmt> ASTScopeImpl::getStmtIfAny() const {
  switch (getKind()) {
    // Statement scope nodes extract the statement directly.
#define STMT_SCOPE_NODE(Name) \
    case ScopeKind::Name: return cast<Name##Scope>(this)->getStmt();
#define SCOPE_NODE(Name)
#include "swift/AST/ASTScopeNodes.def"

    // Everything else returns nullptr.
#define STMT_SCOPE_NODE(Name)
#define SCOPE_NODE(Name) case ScopeKind::Name:
#include "swift/AST/ASTScopeNodes.def"
      return nullptr;
  }
}

NullablePtr<Expr> ASTScopeImpl::getExprIfAny() const {
  switch (getKind()) {
    // Expression scope nodes extract the statement directly.
#define EXPR_SCOPE_NODE(Name) \
    case ScopeKind::Name: return cast<Name##Scope>(this)->getExpr();
#define SCOPE_NODE(Name)
#include "swift/AST/ASTScopeNodes.def"

    // Everything else returns nullptr.
#define EXPR_SCOPE_NODE(Name)
#define SCOPE_NODE(Name) case ScopeKind::Name:
#include "swift/AST/ASTScopeNodes.def"
      return nullptr;
  }
}

SourceManager &ASTScopeImpl::getSourceManager() const {
  return getASTContext().SourceMgr;
}

Stmt *LabeledConditionalStmtScope::getStmt() const {
  return getLabeledConditionalStmt();
}

#pragma mark getLabeledConditionalStmt
LabeledConditionalStmt *IfStmtScope::getLabeledConditionalStmt() const {
  return stmt;
}
LabeledConditionalStmt *WhileStmtScope::getLabeledConditionalStmt() const {
  return stmt;
}
LabeledConditionalStmt *GuardStmtScope::getLabeledConditionalStmt() const {
  return stmt;
}


#pragma mark getASTContext

ASTContext &ASTScopeImpl::getASTContext() const {
  if (auto d = getDeclIfAny())
    return d.get()->getASTContext();
  if (auto sfScope = dyn_cast<ASTSourceFileScope>(this))
    return sfScope->SF->getASTContext();
  return getParent().get()->getASTContext();
}

#pragma mark getSourceFile

const SourceFile *ASTScopeImpl::getSourceFile() const {
  if (auto sourceFileScope = dyn_cast<ASTSourceFileScope>(this))
    return sourceFileScope->SF;

  return getParent().get()->getSourceFile();
}

SourceRange ExtensionScope::getBraces() const { return decl->getBraces(); }

SourceRange NominalTypeScope::getBraces() const { return decl->getBraces(); }

NullablePtr<NominalTypeDecl>
ExtensionScope::getCorrespondingNominalTypeDecl() const {
  return decl->getExtendedNominal();
}

void ASTScopeImpl::preOrderDo(function_ref<void(ASTScopeImpl *)> fn) {
  fn(this);
  preOrderChildrenDo(fn);
}
void ASTScopeImpl::preOrderChildrenDo(function_ref<void(ASTScopeImpl *)> fn) {
  for (auto *child : getChildren())
    child->preOrderDo(fn);
}

void ASTScopeImpl::postOrderDo(function_ref<void(ASTScopeImpl *)> fn) {
  for (auto *child : getChildren())
    child->postOrderDo(fn);
  fn(this);
}