ASTScriptEvaluator.cpp

//===--- ASTScriptEvaluator.cpp -------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2019 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
//
//===----------------------------------------------------------------------===//
///
/// AST script evaluation.
///
//===----------------------------------------------------------------------===//

#include"ASTScript.h"
#include"ASTScriptConfiguration.h"

#include"swift/AST/ASTMangler.h"
#include"swift/AST/ASTWalker.h"
#include"swift/AST/Decl.h"
#include"swift/AST/NameLookup.h"
#include"swift/AST/NameLookupRequests.h"
#include"swift/Frontend/Frontend.h"

usingnamespaceswift;
usingnamespacescripting;

namespace {

classASTScriptWalker : publicASTWalker {
const ASTScript &Script;
 ProtocolDecl *ViewProtocol;

public:
ASTScriptWalker(const ASTScript &script, ProtocolDecl *viewProtocol)
 : Script(script), ViewProtocol(viewProtocol) {}

 MacroWalking getMacroWalkingBehavior() constoverride {
return MacroWalking::Expansion;
 }

 PreWalkAction walkToDeclPre(Decl *D) override {
visit(D);
returnAction::Continue();
 }

voidvisit(const Decl *D) {
auto fn = dyn_cast<AbstractFunctionDecl>(D);
if (!fn) return;

// Suppress warnings.
 (void) Script;

for (auto param : *fn->getParameters()) {
// The parameter must have function type.
auto paramType = param->getInterfaceType();
auto paramFnType = paramType->getAs<FunctionType>();
if (!paramFnType) continue;

// The parameter function must return a type parameter that
// conforms to SwiftUI.View.
auto paramResultType = paramFnType->getResult();
if (!paramResultType->isTypeParameter()) continue;
auto sig = fn->getGenericSignature();
if (!sig->requiresProtocol(paramResultType, ViewProtocol)) continue;

// The parameter must not be a @ViewBuilder parameter.
if (param->getResultBuilderType()) continue;

// Print the function.
printDecl(fn);
 }
 }

voidprintDecl(const ValueDecl *decl) {
// FIXME: there's got to be some better way to print an exact reference
// to a declaration, including its context.
printDecl(llvm::outs(), decl);
llvm::outs() << "\n";
 }

voidprintDecl(llvm::raw_ostream &out, const ValueDecl *decl) {
if (auto accessor = dyn_cast<AccessorDecl>(decl)) {
printDecl(out, accessor->getStorage());
 out << ".(accessor)";
 } else {
printDeclContext(out, decl->getDeclContext());
 out << decl->getName();
 }
 }

voidprintDeclContext(llvm::raw_ostream &out, const DeclContext *dc) {
if (!dc) return;
if (auto module = dyn_cast<ModuleDecl>(dc)) {
 out << module->getName() << ".";
 } elseif (auto extension = dyn_cast<ExtensionDecl>(dc)) {
auto *extended = extension->getExtendedNominal();
if (extended) {
printDecl(out, extended);
 out << ".";
 }
 } elseif (auto decl = dyn_cast_or_null<ValueDecl>(dc->getAsDecl())) {
printDecl(out, decl);
 out << ".";
 } else {
printDeclContext(out, dc->getParent());
 }
 }
};

}

boolASTScript::execute() const {
// Hardcode the actual query we want to execute here.

auto &ctx = Config.Compiler.getASTContext();
auto swiftUI = ctx.getLoadedModule(ctx.getIdentifier("SwiftUI"));
if (!swiftUI) {
llvm::errs() << "error: SwiftUI module not loaded\n";
returntrue;
 }

auto descriptor =
UnqualifiedLookupDescriptor(DeclNameRef(ctx.getIdentifier("View")),
 swiftUI);
auto viewLookup = evaluateOrDefault(ctx.evaluator,
 UnqualifiedLookupRequest{descriptor}, {});
auto viewProtocol =
 dyn_cast_or_null<ProtocolDecl>(viewLookup.getSingleTypeResult());
if (!viewProtocol) {
llvm::errs() << "error: couldn't find SwiftUI.View protocol\n";
returntrue;
 }

 SmallVector<Decl*, 128> topLevelDecls;
 swiftUI->getTopLevelDecls(topLevelDecls);

llvm::errs() << "found " << topLevelDecls.size() << " top-level declarations\n";

 ASTScriptWalker walker(*this, viewProtocol);
for (auto decl : topLevelDecls) {
 decl->walk(walker);
 }

returnfalse;
}