mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
a73e44a78f
Use `preCheckTarget` to pre-check the body, allowing us to replace `PreCheckResultBuilderRequest` with a request that only checks the brace for ReturnStmts.
1586 lines
56 KiB
C++
1586 lines
56 KiB
C++
//===--- BuilderTransform.cpp - Result-builder transformation -----------===//
|
|
//
|
|
// This source file is part of the Swift.org open source project
|
|
//
|
|
// Copyright (c) 2014 - 2018 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 routines associated with the result-builder
|
|
// transformation.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "MiscDiagnostics.h"
|
|
#include "TypeCheckAvailability.h"
|
|
#include "TypeChecker.h"
|
|
#include "swift/AST/ASTPrinter.h"
|
|
#include "swift/AST/ASTVisitor.h"
|
|
#include "swift/AST/ASTWalker.h"
|
|
#include "swift/AST/NameLookup.h"
|
|
#include "swift/AST/NameLookupRequests.h"
|
|
#include "swift/AST/ParameterList.h"
|
|
#include "swift/AST/TypeCheckRequests.h"
|
|
#include "swift/Basic/Assertions.h"
|
|
#include "swift/Sema/ConstraintSystem.h"
|
|
#include "swift/Sema/IDETypeChecking.h"
|
|
#include "swift/Sema/SolutionResult.h"
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include <iterator>
|
|
#include <map>
|
|
#include <memory>
|
|
#include <tuple>
|
|
#include <utility>
|
|
|
|
using namespace swift;
|
|
using namespace constraints;
|
|
|
|
namespace {
|
|
|
|
/// Find the first #available condition within the statement condition,
|
|
/// or return NULL if there isn't one.
|
|
const StmtConditionElement *findAvailabilityCondition(StmtCondition stmtCond) {
|
|
for (const auto &cond : stmtCond) {
|
|
switch (cond.getKind()) {
|
|
case StmtConditionElement::CK_Boolean:
|
|
case StmtConditionElement::CK_PatternBinding:
|
|
case StmtConditionElement::CK_HasSymbol:
|
|
continue;
|
|
|
|
case StmtConditionElement::CK_Availability:
|
|
return &cond;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
class ResultBuilderTransform
|
|
: private StmtVisitor<ResultBuilderTransform, NullablePtr<Stmt>,
|
|
NullablePtr<VarDecl>> {
|
|
friend StmtVisitor<ResultBuilderTransform, NullablePtr<Stmt>,
|
|
NullablePtr<VarDecl>>;
|
|
|
|
using UnsupportedElt = SkipUnhandledConstructInResultBuilder::UnhandledNode;
|
|
|
|
ASTContext &ctx;
|
|
DeclContext *dc;
|
|
ResultBuilder builder;
|
|
|
|
/// The source range of the body.
|
|
SourceRange bodyRange;
|
|
|
|
/// The result type of this result builder body.
|
|
Type ResultType;
|
|
|
|
/// The first recorded unsupported element discovered by the transformation.
|
|
UnsupportedElt FirstUnsupported;
|
|
|
|
public:
|
|
ResultBuilderTransform(ConstraintSystem &cs, DeclContext *dc,
|
|
SourceRange bodyRange, Type builderType, Type resultTy)
|
|
: ctx(cs.getASTContext()), dc(dc), builder(cs, dc, builderType),
|
|
bodyRange(bodyRange), ResultType(resultTy) {}
|
|
|
|
UnsupportedElt getUnsupportedElement() const { return FirstUnsupported; }
|
|
|
|
BraceStmt *apply(BraceStmt *braceStmt) {
|
|
auto newBody = visitBraceStmt(braceStmt, /*bodyVar=*/nullptr);
|
|
if (!newBody)
|
|
return nullptr;
|
|
return castToStmt<BraceStmt>(newBody.get());
|
|
}
|
|
|
|
VarDecl *getBuilderSelf() const { return builder.getBuilderSelf(); }
|
|
|
|
protected:
|
|
NullablePtr<Stmt> failTransform(UnsupportedElt unsupported) {
|
|
recordUnsupported(unsupported);
|
|
return nullptr;
|
|
}
|
|
|
|
VarDecl *recordVar(PatternBindingDecl *PB,
|
|
SmallVectorImpl<ASTNode> &container) {
|
|
container.push_back(PB);
|
|
container.push_back(PB->getSingleVar());
|
|
return PB->getSingleVar();
|
|
}
|
|
|
|
VarDecl *captureExpr(Expr *expr, SmallVectorImpl<ASTNode> &container) {
|
|
auto *var = builder.buildVar(expr->getStartLoc());
|
|
Pattern *pattern = NamedPattern::createImplicit(ctx, var);
|
|
auto *PB = PatternBindingDecl::createImplicit(
|
|
ctx, StaticSpellingKind::None, pattern, expr, dc, var->getStartLoc());
|
|
return recordVar(PB, container);
|
|
}
|
|
|
|
VarDecl *buildPlaceholderVar(SourceLoc loc,
|
|
SmallVectorImpl<ASTNode> &container,
|
|
Type type = Type(), Expr *initExpr = nullptr) {
|
|
auto *var = builder.buildVar(loc);
|
|
Pattern *placeholder = TypedPattern::createImplicit(
|
|
ctx, NamedPattern::createImplicit(ctx, var),
|
|
type ? type : PlaceholderType::get(ctx, var));
|
|
auto *PB = PatternBindingDecl::createImplicit(
|
|
ctx, StaticSpellingKind::None, placeholder, /*init=*/initExpr, dc,
|
|
var->getStartLoc());
|
|
return recordVar(PB, container);
|
|
}
|
|
|
|
AssignExpr *buildAssignment(VarDecl *dst, VarDecl *src) {
|
|
auto *dstRef = builder.buildVarRef(dst, /*Loc=*/SourceLoc());
|
|
auto *srcRef = builder.buildVarRef(src, /*Loc=*/SourceLoc());
|
|
return new (ctx) AssignExpr(dstRef, /*EqualLoc=*/SourceLoc(), srcRef,
|
|
/*Implicit=*/true);
|
|
}
|
|
|
|
AssignExpr *buildAssignment(VarDecl *dst, Expr *srcExpr) {
|
|
auto *dstRef = builder.buildVarRef(dst, /*Loc=*/SourceLoc());
|
|
return new (ctx) AssignExpr(dstRef, /*EqualLoc=*/SourceLoc(), srcExpr,
|
|
/*implicit=*/true);
|
|
}
|
|
|
|
void recordUnsupported(UnsupportedElt node) {
|
|
if (!FirstUnsupported)
|
|
FirstUnsupported = node;
|
|
}
|
|
|
|
#define UNSUPPORTED_STMT(StmtClass) \
|
|
NullablePtr<Stmt> visit##StmtClass##Stmt(StmtClass##Stmt *stmt, \
|
|
NullablePtr<VarDecl> var) { \
|
|
return failTransform(stmt); \
|
|
}
|
|
|
|
/// Visit the element of a brace statement, returning \c None if the element
|
|
/// was transformed successfully, or an unsupported element if the element
|
|
/// cannot be handled.
|
|
std::optional<UnsupportedElt>
|
|
transformBraceElement(ASTNode element, SmallVectorImpl<ASTNode> &newBody,
|
|
SmallVectorImpl<Expr *> &buildBlockArguments) {
|
|
if (auto *returnStmt = getAsStmt<ReturnStmt>(element)) {
|
|
assert(returnStmt->isImplicit());
|
|
element = returnStmt->getResult();
|
|
}
|
|
// Unwrap an implicit ThenStmt.
|
|
if (auto *thenStmt = getAsStmt<ThenStmt>(element)) {
|
|
if (thenStmt->isImplicit())
|
|
element = thenStmt->getResult();
|
|
}
|
|
|
|
if (auto *decl = element.dyn_cast<Decl *>()) {
|
|
switch (decl->getKind()) {
|
|
// Just ignore #if; the chosen children should appear in
|
|
// the surrounding context. This isn't good for source
|
|
// tools but it at least works.
|
|
case DeclKind::IfConfig:
|
|
// Skip #warning/#error; we'll handle them when applying
|
|
// the builder.
|
|
case DeclKind::PoundDiagnostic:
|
|
case DeclKind::PatternBinding:
|
|
case DeclKind::Var:
|
|
case DeclKind::Param:
|
|
newBody.push_back(element);
|
|
return std::nullopt;
|
|
|
|
default:
|
|
return UnsupportedElt(decl);
|
|
}
|
|
llvm_unreachable("Unhandled case in switch!");
|
|
}
|
|
|
|
if (auto *stmt = element.dyn_cast<Stmt *>()) {
|
|
// Throw is allowed as is.
|
|
if (auto *throwStmt = dyn_cast<ThrowStmt>(stmt)) {
|
|
newBody.push_back(throwStmt);
|
|
return std::nullopt;
|
|
}
|
|
|
|
if (ctx.CompletionCallback && stmt->getSourceRange().isValid() &&
|
|
!containsIDEInspectionTarget(stmt->getSourceRange(), ctx.SourceMgr) &&
|
|
!isa<GuardStmt>(stmt)) {
|
|
// A statement that doesn't contain the code completion expression can't
|
|
// influence the type of the code completion expression, so we can skip
|
|
// it to improve performance.
|
|
return std::nullopt;
|
|
}
|
|
|
|
// Allocate variable with a placeholder type
|
|
auto *resultVar = buildPlaceholderVar(stmt->getStartLoc(), newBody);
|
|
|
|
auto result = visit(stmt, resultVar);
|
|
if (!result)
|
|
return UnsupportedElt(stmt);
|
|
|
|
newBody.push_back(result.get());
|
|
buildBlockArguments.push_back(
|
|
builder.buildVarRef(resultVar, stmt->getStartLoc()));
|
|
return std::nullopt;
|
|
}
|
|
|
|
auto *expr = element.get<Expr *>();
|
|
if (auto *SVE = dyn_cast<SingleValueStmtExpr>(expr)) {
|
|
// This should never be treated as an expression in a result builder, it
|
|
// should have statement semantics.
|
|
return transformBraceElement(SVE->getStmt(), newBody,
|
|
buildBlockArguments);
|
|
}
|
|
if (builder.supports(ctx.Id_buildExpression)) {
|
|
expr = builder.buildCall(expr->getStartLoc(), ctx.Id_buildExpression,
|
|
{expr}, {Identifier()});
|
|
}
|
|
|
|
if (isa<CodeCompletionExpr>(expr)) {
|
|
// Insert the CodeCompletionExpr directly into the buildBlock call. That
|
|
// way, we can extract the contextual type of the code completion token
|
|
// to rank code completion items that match the type expected by
|
|
// buildBlock higher.
|
|
buildBlockArguments.push_back(expr);
|
|
} else if (ctx.CompletionCallback && expr->getSourceRange().isValid() &&
|
|
containsIDEInspectionTarget(bodyRange, ctx.SourceMgr) &&
|
|
!containsIDEInspectionTarget(expr->getSourceRange(),
|
|
ctx.SourceMgr)) {
|
|
// A top-level expression that doesn't contain the code completion
|
|
// expression can't influence the type of the code completion expression
|
|
// if they're in the same result builder. Add a variable for it that we
|
|
// can put into the buildBlock call but don't add the expression itself
|
|
// into the transformed body to improve performance.
|
|
auto *resultVar = buildPlaceholderVar(expr->getStartLoc(), newBody);
|
|
buildBlockArguments.push_back(
|
|
builder.buildVarRef(resultVar, expr->getStartLoc()));
|
|
} else {
|
|
auto *capture = captureExpr(expr, newBody);
|
|
// A reference to the synthesized variable is passed as an argument
|
|
// to buildBlock.
|
|
buildBlockArguments.push_back(
|
|
builder.buildVarRef(capture, element.getStartLoc()));
|
|
}
|
|
|
|
return std::nullopt;
|
|
}
|
|
|
|
std::pair<NullablePtr<Expr>, std::optional<UnsupportedElt>>
|
|
transform(BraceStmt *braceStmt, SmallVectorImpl<ASTNode> &newBody) {
|
|
SmallVector<Expr *, 4> buildBlockArguments;
|
|
|
|
auto failTransform = [&](UnsupportedElt unsupported) {
|
|
return std::make_pair(nullptr, unsupported);
|
|
};
|
|
|
|
for (auto element : braceStmt->getElements()) {
|
|
if (auto unsupported =
|
|
transformBraceElement(element, newBody, buildBlockArguments)) {
|
|
// When in code completion mode, simply ignore unsported constructs to
|
|
// get results for anything that's unrelated to the unsupported
|
|
// constructs.
|
|
if (!ctx.CompletionCallback) {
|
|
return failTransform(*unsupported);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Synthesize `buildBlock` or `buildPartial` based on captured arguments.
|
|
{
|
|
// If the builder supports `buildPartialBlock(first:)` and
|
|
// `buildPartialBlock(accumulated:next:)`, use this to combine
|
|
// sub-expressions pairwise.
|
|
if (!buildBlockArguments.empty() && builder.canUseBuildPartialBlock()) {
|
|
// let v0 = Builder.buildPartialBlock(first: arg_0)
|
|
// let v1 = Builder.buildPartialBlock(accumulated: v0, next: arg_1)
|
|
// ...
|
|
// let vN = Builder.buildPartialBlock(accumulated: vN-1, next: argN)
|
|
auto *buildPartialFirst = builder.buildCall(
|
|
braceStmt->getStartLoc(), ctx.Id_buildPartialBlock,
|
|
{buildBlockArguments.front()},
|
|
/*argLabels=*/{ctx.Id_first});
|
|
|
|
auto *buildBlockVar = captureExpr(buildPartialFirst, newBody);
|
|
|
|
for (auto *argExpr : llvm::drop_begin(buildBlockArguments)) {
|
|
auto *accumPartialBlock = builder.buildCall(
|
|
braceStmt->getStartLoc(), ctx.Id_buildPartialBlock,
|
|
{builder.buildVarRef(buildBlockVar, argExpr->getStartLoc()),
|
|
argExpr},
|
|
{ctx.Id_accumulated, ctx.Id_next});
|
|
buildBlockVar = captureExpr(accumPartialBlock, newBody);
|
|
}
|
|
|
|
return std::make_pair(
|
|
builder.buildVarRef(buildBlockVar, braceStmt->getStartLoc()),
|
|
std::nullopt);
|
|
}
|
|
// If `buildBlock` does not exist at this point, it could be the case that
|
|
// `buildPartialBlock` did not have the sufficient availability for this
|
|
// call site. Diagnose it.
|
|
else if (!builder.supports(ctx.Id_buildBlock)) {
|
|
ctx.Diags.diagnose(
|
|
braceStmt->getStartLoc(),
|
|
diag::result_builder_missing_available_buildpartialblock,
|
|
builder.getType());
|
|
return failTransform(braceStmt);
|
|
}
|
|
|
|
// Otherwise, call `buildBlock` on all subexpressions.
|
|
// Call Builder.buildBlock(... args ...)
|
|
auto *buildBlock = builder.buildCall(
|
|
braceStmt->getStartLoc(), ctx.Id_buildBlock, buildBlockArguments,
|
|
/*argLabels=*/{});
|
|
return std::make_pair(buildBlock, std::nullopt);
|
|
}
|
|
}
|
|
|
|
std::pair<bool, UnsupportedElt>
|
|
transform(BraceStmt *braceStmt, NullablePtr<VarDecl> bodyVar,
|
|
SmallVectorImpl<ASTNode> &elements) {
|
|
// Arguments passed to a synthesized `build{Partial}Block`.
|
|
SmallVector<Expr *, 4> buildBlockArguments;
|
|
|
|
auto failure = [&](UnsupportedElt element) {
|
|
return std::make_pair(true, element);
|
|
};
|
|
|
|
NullablePtr<Expr> buildBlockVarRef;
|
|
std::optional<UnsupportedElt> unsupported;
|
|
|
|
std::tie(buildBlockVarRef, unsupported) = transform(braceStmt, elements);
|
|
if (unsupported)
|
|
return failure(*unsupported);
|
|
|
|
// If this is not a top-level brace statement, we need to form an
|
|
// assignment from the `build{Partial}Block` call result variable
|
|
// to the provided one.
|
|
//
|
|
// Use start loc for the return statement so any contextual issues
|
|
// are attached to the beginning of the brace instead of its end.
|
|
auto resultLoc = braceStmt->getStartLoc();
|
|
if (bodyVar) {
|
|
elements.push_back(
|
|
new (ctx) AssignExpr(builder.buildVarRef(bodyVar.get(), resultLoc),
|
|
/*EqualLoc=*/SourceLoc(), buildBlockVarRef.get(),
|
|
/*Implicit=*/true));
|
|
} else {
|
|
Expr *buildBlockResult = buildBlockVarRef.get();
|
|
// Otherwise, it's a top-level brace and we need to synthesize
|
|
// a call to `buildFialBlock` if supported.
|
|
if (builder.supports(ctx.Id_buildFinalResult, {Identifier()})) {
|
|
buildBlockResult =
|
|
builder.buildCall(resultLoc, ctx.Id_buildFinalResult,
|
|
{buildBlockResult}, {Identifier()});
|
|
}
|
|
|
|
elements.push_back(
|
|
ReturnStmt::createImplicit(ctx, resultLoc, buildBlockResult));
|
|
}
|
|
|
|
return std::make_pair(false, UnsupportedElt());
|
|
}
|
|
|
|
BraceStmt *cloneBraceWith(BraceStmt *braceStmt,
|
|
SmallVectorImpl<ASTNode> &elements) {
|
|
auto lBrace = braceStmt ? braceStmt->getLBraceLoc() : SourceLoc();
|
|
auto rBrace = braceStmt ? braceStmt->getRBraceLoc() : SourceLoc();
|
|
bool implicit = braceStmt ? braceStmt->isImplicit() : true;
|
|
|
|
return BraceStmt::create(ctx, lBrace, elements, rBrace, implicit);
|
|
}
|
|
|
|
NullablePtr<Stmt> visitBraceStmt(BraceStmt *braceStmt,
|
|
NullablePtr<VarDecl> bodyVar) {
|
|
SmallVector<ASTNode, 4> elements;
|
|
|
|
bool failed;
|
|
UnsupportedElt unsupported;
|
|
|
|
std::tie(failed, unsupported) = transform(braceStmt, bodyVar, elements);
|
|
|
|
if (failed)
|
|
return failTransform(unsupported);
|
|
|
|
return cloneBraceWith(braceStmt, elements);
|
|
}
|
|
|
|
NullablePtr<Stmt> visitDoStmt(DoStmt *doStmt, NullablePtr<VarDecl> doVar) {
|
|
auto body = visitBraceStmt(doStmt->getBody(), doVar);
|
|
if (!body)
|
|
return nullptr;
|
|
|
|
return new (ctx) DoStmt(doStmt->getLabelInfo(), doStmt->getDoLoc(),
|
|
cast<BraceStmt>(body.get()), doStmt->isImplicit());
|
|
}
|
|
|
|
NullablePtr<Stmt> visitIfStmt(IfStmt *ifStmt, NullablePtr<VarDecl> ifVar) {
|
|
// Check whether the chain is buildable and whether it terminates
|
|
// without an `else`.
|
|
bool isOptional = false;
|
|
unsigned numPayloads = 0;
|
|
if (!isBuildableIfChain(ifStmt, numPayloads, isOptional))
|
|
return failTransform(ifStmt);
|
|
|
|
SmallVector<std::pair<Expr *, Stmt *>, 4> branchVarRefs;
|
|
|
|
auto transformed = transformIf(ifStmt, branchVarRefs);
|
|
if (!transformed)
|
|
return failTransform(ifStmt);
|
|
|
|
// Let's wrap `if` statement into a `do` and inject `type-join`
|
|
// operation with appropriate combination of `buildEither` that
|
|
// would get re-distributed after inference.
|
|
SmallVector<ASTNode, 4> doBody;
|
|
{
|
|
ifStmt = transformed.get();
|
|
|
|
// `if` goes first.
|
|
doBody.push_back(ifStmt);
|
|
|
|
assert(numPayloads == branchVarRefs.size());
|
|
|
|
SmallVector<Expr *, 4> buildEitherCalls;
|
|
for (unsigned i = 0; i != numPayloads; i++) {
|
|
Expr *branchVarRef;
|
|
Stmt *anchor;
|
|
|
|
std::tie(branchVarRef, anchor) = branchVarRefs[i];
|
|
|
|
auto *builderCall =
|
|
buildWrappedChainPayload(branchVarRef, i, numPayloads, isOptional);
|
|
|
|
// The operand should have optional type if we had optional results,
|
|
// so we just need to call `buildIf` now, since we're at the top level.
|
|
if (isOptional) {
|
|
builderCall = builder.buildCall(ifStmt->getThenStmt()->getStartLoc(),
|
|
builder.getBuildOptionalId(),
|
|
builderCall, /*argLabels=*/{});
|
|
}
|
|
|
|
buildEitherCalls.push_back(builderCall);
|
|
}
|
|
|
|
// If there is no `else` branch we need to build one.
|
|
// It consists a `buildOptional` call that uses `nil` as an argument.
|
|
//
|
|
// ```
|
|
// {
|
|
// $__builderResult = buildOptional(nil)
|
|
// }
|
|
// ```
|
|
//
|
|
// Type of `nil` is going to be inferred from `$__builderResult`.
|
|
if (!hasUnconditionalElse(ifStmt)) {
|
|
assert(isOptional);
|
|
|
|
auto *nil =
|
|
new (ctx) NilLiteralExpr(ifStmt->getEndLoc(), /*implicit=*/true);
|
|
|
|
buildEitherCalls.push_back(builder.buildCall(
|
|
/*loc=*/ifStmt->getEndLoc(), builder.getBuildOptionalId(), nil,
|
|
/*argLabels=*/{}));
|
|
}
|
|
|
|
auto *ifVarRef = builder.buildVarRef(ifVar.get(), ifStmt->getStartLoc());
|
|
doBody.push_back(TypeJoinExpr::create(ctx, ifVarRef, buildEitherCalls));
|
|
}
|
|
|
|
return DoStmt::createImplicit(ctx, LabeledStmtInfo(), doBody);
|
|
}
|
|
|
|
NullablePtr<IfStmt>
|
|
transformIf(IfStmt *ifStmt,
|
|
SmallVectorImpl<std::pair<Expr *, Stmt *>> &branchVarRefs) {
|
|
std::optional<UnsupportedElt> unsupported;
|
|
|
|
// If there is a #available in the condition, wrap the 'then' or 'else'
|
|
// in a call to buildLimitedAvailability(_:).
|
|
auto availabilityCond = findAvailabilityCondition(ifStmt->getCond());
|
|
bool supportsAvailability =
|
|
availabilityCond && builder.supports(ctx.Id_buildLimitedAvailability);
|
|
|
|
NullablePtr<Expr> thenVarRef;
|
|
NullablePtr<BraceStmt> thenBranch;
|
|
{
|
|
SmallVector<ASTNode, 4> thenBody;
|
|
|
|
auto *ifBraceStmt = cast<BraceStmt>(ifStmt->getThenStmt());
|
|
|
|
std::tie(thenVarRef, unsupported) = transform(ifBraceStmt, thenBody);
|
|
if (unsupported) {
|
|
recordUnsupported(*unsupported);
|
|
return nullptr;
|
|
}
|
|
|
|
if (supportsAvailability &&
|
|
!availabilityCond->getAvailability()->isUnavailability()) {
|
|
auto *builderCall = builder.buildCall(
|
|
ifBraceStmt->getStartLoc(), ctx.Id_buildLimitedAvailability,
|
|
{thenVarRef.get()}, {Identifier()});
|
|
|
|
thenVarRef = builder.buildVarRef(captureExpr(builderCall, thenBody),
|
|
ifBraceStmt->getStartLoc());
|
|
}
|
|
|
|
thenBranch = cloneBraceWith(ifBraceStmt, thenBody);
|
|
branchVarRefs.push_back({thenVarRef.get(), thenBranch.get()});
|
|
}
|
|
|
|
NullablePtr<Stmt> elseBranch;
|
|
|
|
if (auto *elseStmt = ifStmt->getElseStmt()) {
|
|
NullablePtr<Expr> elseVarRef;
|
|
|
|
if (auto *innerIfStmt = getAsStmt<IfStmt>(elseStmt)) {
|
|
elseBranch = transformIf(innerIfStmt, branchVarRefs);
|
|
if (!elseBranch) {
|
|
recordUnsupported(innerIfStmt);
|
|
return nullptr;
|
|
}
|
|
} else {
|
|
auto *elseBraceStmt = cast<BraceStmt>(elseStmt);
|
|
SmallVector<ASTNode> elseBody;
|
|
|
|
std::tie(elseVarRef, unsupported) = transform(elseBraceStmt, elseBody);
|
|
if (unsupported) {
|
|
recordUnsupported(*unsupported);
|
|
return nullptr;
|
|
}
|
|
|
|
// If there is a #unavailable in the condition, wrap the 'else' in a
|
|
// call to buildLimitedAvailability(_:).
|
|
if (supportsAvailability &&
|
|
availabilityCond->getAvailability()->isUnavailability()) {
|
|
auto *builderCall = builder.buildCall(
|
|
elseBraceStmt->getStartLoc(), ctx.Id_buildLimitedAvailability,
|
|
{elseVarRef.get()}, {Identifier()});
|
|
|
|
elseVarRef = builder.buildVarRef(captureExpr(builderCall, elseBody),
|
|
elseBraceStmt->getStartLoc());
|
|
}
|
|
|
|
elseBranch = cloneBraceWith(elseBraceStmt, elseBody);
|
|
branchVarRefs.push_back({elseVarRef.get(), elseBranch.get()});
|
|
}
|
|
}
|
|
|
|
return new (ctx)
|
|
IfStmt(ifStmt->getLabelInfo(), ifStmt->getIfLoc(), ifStmt->getCond(),
|
|
thenBranch.get(), ifStmt->getElseLoc(),
|
|
elseBranch.getPtrOrNull(), ifStmt->isImplicit());
|
|
}
|
|
|
|
NullablePtr<Stmt> visitSwitchStmt(SwitchStmt *switchStmt,
|
|
NullablePtr<VarDecl> switchVar) {
|
|
// For a do statement wrapping this switch that contains all of the
|
|
// `buildEither` calls that would get injected back into `case` bodies
|
|
// after solving is done.
|
|
//
|
|
// This is necessary because `buildEither requires type information from
|
|
// both sides to be available, so all case statements have to be
|
|
// type-checked first.
|
|
SmallVector<ASTNode, 4> doBody;
|
|
|
|
SmallVector<ASTNode, 4> cases;
|
|
SmallVector<Expr *, 4> caseVarRefs;
|
|
|
|
for (auto *caseStmt : switchStmt->getCases()) {
|
|
auto transformed = transformCase(caseStmt);
|
|
if (!transformed)
|
|
return failTransform(caseStmt);
|
|
|
|
cases.push_back(transformed->second);
|
|
caseVarRefs.push_back(transformed->first);
|
|
}
|
|
|
|
// If there are no 'case' statements in the body let's try
|
|
// to diagnose this situation via limited exhaustiveness check
|
|
// before failing a builder transform, otherwise type-checker
|
|
// might end up without any diagnostics which leads to crashes
|
|
// in SILGen.
|
|
if (caseVarRefs.empty()) {
|
|
TypeChecker::checkSwitchExhaustiveness(switchStmt, dc,
|
|
/*limitChecking=*/true);
|
|
return failTransform(switchStmt);
|
|
}
|
|
|
|
auto *transformedSwitch = SwitchStmt::create(
|
|
switchStmt->getLabelInfo(), switchStmt->getSwitchLoc(),
|
|
switchStmt->getSubjectExpr(), switchStmt->getLBraceLoc(), cases,
|
|
switchStmt->getRBraceLoc(), switchStmt->getEndLoc(), ctx);
|
|
|
|
doBody.push_back(transformedSwitch);
|
|
|
|
SmallVector<Expr *, 4> injectedExprs;
|
|
for (auto idx : indices(caseVarRefs)) {
|
|
auto *caseVarRef = caseVarRefs[idx];
|
|
|
|
// Build the expression that injects the case variable into appropriate
|
|
// buildEither(first:)/buildEither(second:) chain.
|
|
Expr *injectedCaseExpr = buildWrappedChainPayload(
|
|
caseVarRef, idx, caseVarRefs.size(), /*isOptional=*/false);
|
|
|
|
injectedExprs.push_back(injectedCaseExpr);
|
|
}
|
|
|
|
auto *switchVarRef =
|
|
builder.buildVarRef(switchVar.get(), switchStmt->getEndLoc());
|
|
doBody.push_back(TypeJoinExpr::create(ctx, switchVarRef, injectedExprs));
|
|
|
|
return DoStmt::createImplicit(ctx, LabeledStmtInfo(), doBody);
|
|
}
|
|
|
|
std::optional<std::pair<Expr *, CaseStmt *>>
|
|
transformCase(CaseStmt *caseStmt) {
|
|
auto *body = caseStmt->getBody();
|
|
|
|
// Explicitly disallow `case` statements with empty bodies
|
|
// since that helps to diagnose other issues with switch
|
|
// statements by excluding invalid cases.
|
|
if (auto *BS = dyn_cast<BraceStmt>(body)) {
|
|
if (BS->getNumElements() == 0) {
|
|
// HACK: still allow empty bodies if typechecking for code
|
|
// completion. Code completion ignores diagnostics
|
|
// and won't get any types if we fail.
|
|
if (!ctx.SourceMgr.hasIDEInspectionTargetBuffer())
|
|
return std::nullopt;
|
|
}
|
|
}
|
|
|
|
NullablePtr<Expr> caseVarRef;
|
|
std::optional<UnsupportedElt> unsupported;
|
|
SmallVector<ASTNode, 4> newBody;
|
|
|
|
std::tie(caseVarRef, unsupported) = transform(body, newBody);
|
|
|
|
if (unsupported) {
|
|
recordUnsupported(*unsupported);
|
|
return std::nullopt;
|
|
}
|
|
|
|
auto *newCase = CaseStmt::create(
|
|
ctx, caseStmt->getParentKind(), caseStmt->getLoc(),
|
|
caseStmt->getCaseLabelItems(),
|
|
caseStmt->hasUnknownAttr() ? caseStmt->getStartLoc() : SourceLoc(),
|
|
caseStmt->getItemTerminatorLoc(), cloneBraceWith(body, newBody),
|
|
caseStmt->getCaseBodyVariablesOrEmptyArray(), caseStmt->isImplicit(),
|
|
caseStmt->getFallthroughStmt());
|
|
|
|
return std::make_pair(caseVarRef.get(), newCase);
|
|
}
|
|
|
|
/// do {
|
|
/// var $__forEach = []
|
|
/// for ... in ... {
|
|
/// ...
|
|
/// $__builderVar = buildBlock(...)
|
|
/// $__forEach.append($__builderVar)
|
|
/// }
|
|
/// buildArray($__forEach)
|
|
/// }
|
|
NullablePtr<Stmt> visitForEachStmt(ForEachStmt *forEachStmt,
|
|
NullablePtr<VarDecl> forEachVar) {
|
|
// for...in statements are handled via buildArray(_:); bail out if the
|
|
// builder does not support it.
|
|
if (!builder.supports(ctx.Id_buildArray))
|
|
return failTransform(forEachStmt);
|
|
|
|
// For-each statements require the Sequence protocol. If we don't have
|
|
// it (which generally means the standard library isn't loaded), fall
|
|
// out of the result-builder path entirely to let normal type checking
|
|
// take care of this.
|
|
auto sequenceProto = TypeChecker::getProtocol(
|
|
dc->getASTContext(), forEachStmt->getForLoc(),
|
|
forEachStmt->getAwaitLoc().isValid() ? KnownProtocolKind::AsyncSequence
|
|
: KnownProtocolKind::Sequence);
|
|
if (!sequenceProto)
|
|
return failTransform(forEachStmt);
|
|
|
|
SmallVector<ASTNode, 4> doBody;
|
|
SourceLoc endLoc = forEachStmt->getEndLoc();
|
|
|
|
// Build a variable that is going to hold array of results produced
|
|
// by each iteration of the loop.
|
|
//
|
|
// Not that it's not going to be initialized here, that would happen
|
|
// only when a solution is found.
|
|
VarDecl *arrayVar = buildPlaceholderVar(
|
|
forEachStmt->getEndLoc(), doBody,
|
|
ArraySliceType::get(PlaceholderType::get(ctx, forEachVar.get())),
|
|
ArrayExpr::create(ctx, /*LBrace=*/endLoc, /*Elements=*/{},
|
|
/*Commas=*/{}, /*RBrace=*/endLoc));
|
|
|
|
NullablePtr<Expr> bodyVarRef;
|
|
std::optional<UnsupportedElt> unsupported;
|
|
|
|
SmallVector<ASTNode, 4> newBody;
|
|
{
|
|
std::tie(bodyVarRef, unsupported) =
|
|
transform(forEachStmt->getBody(), newBody);
|
|
if (unsupported)
|
|
return failTransform(*unsupported);
|
|
|
|
// Form a call to Array.append(_:) to add the result of executing each
|
|
// iteration of the loop body to the array formed above.
|
|
{
|
|
auto arrayVarRef = builder.buildVarRef(arrayVar, endLoc);
|
|
auto arrayAppendRef = new (ctx) UnresolvedDotExpr(
|
|
arrayVarRef, endLoc, DeclNameRef(ctx.getIdentifier("append")),
|
|
DeclNameLoc(endLoc), /*implicit=*/true);
|
|
arrayAppendRef->setFunctionRefKind(FunctionRefKind::SingleApply);
|
|
|
|
auto *argList = ArgumentList::createImplicit(
|
|
ctx, endLoc, {Argument::unlabeled(bodyVarRef.get())}, endLoc);
|
|
|
|
newBody.push_back(
|
|
CallExpr::createImplicit(ctx, arrayAppendRef, argList));
|
|
}
|
|
}
|
|
|
|
auto *newForEach = new (ctx)
|
|
ForEachStmt(forEachStmt->getLabelInfo(), forEachStmt->getForLoc(),
|
|
forEachStmt->getTryLoc(), forEachStmt->getAwaitLoc(),
|
|
forEachStmt->getPattern(), forEachStmt->getInLoc(),
|
|
forEachStmt->getParsedSequence(),
|
|
forEachStmt->getWhereLoc(), forEachStmt->getWhere(),
|
|
cloneBraceWith(forEachStmt->getBody(), newBody),
|
|
forEachStmt->isImplicit());
|
|
|
|
// For a body of new `do` statement that holds updated `for-in` loop
|
|
// and epilog that consists of a call to `buildArray` that forms the
|
|
// final result.
|
|
{
|
|
// Modified `for { ... }`
|
|
doBody.push_back(newForEach);
|
|
|
|
// $__forEach = buildArray($__arrayVar)
|
|
doBody.push_back(buildAssignment(
|
|
forEachVar.get(),
|
|
builder.buildCall(forEachStmt->getEndLoc(), ctx.Id_buildArray,
|
|
{builder.buildVarRef(arrayVar, endLoc)},
|
|
{Identifier()})));
|
|
}
|
|
|
|
return DoStmt::createImplicit(ctx, LabeledStmtInfo(), doBody);
|
|
}
|
|
|
|
UNSUPPORTED_STMT(Throw)
|
|
UNSUPPORTED_STMT(Return)
|
|
UNSUPPORTED_STMT(Yield)
|
|
UNSUPPORTED_STMT(Then)
|
|
UNSUPPORTED_STMT(Discard)
|
|
UNSUPPORTED_STMT(Defer)
|
|
UNSUPPORTED_STMT(Guard)
|
|
UNSUPPORTED_STMT(While)
|
|
UNSUPPORTED_STMT(DoCatch)
|
|
UNSUPPORTED_STMT(RepeatWhile)
|
|
UNSUPPORTED_STMT(Break)
|
|
UNSUPPORTED_STMT(Continue)
|
|
UNSUPPORTED_STMT(Fallthrough)
|
|
UNSUPPORTED_STMT(Fail)
|
|
UNSUPPORTED_STMT(PoundAssert)
|
|
UNSUPPORTED_STMT(Case)
|
|
|
|
#undef UNSUPPORTED_STMT
|
|
|
|
private:
|
|
static bool isBuildableIfChainRecursive(IfStmt *ifStmt, unsigned &numPayloads,
|
|
bool &isOptional) {
|
|
// The 'then' clause contributes a payload.
|
|
++numPayloads;
|
|
|
|
// If there's an 'else' clause, it contributes payloads:
|
|
if (auto elseStmt = ifStmt->getElseStmt()) {
|
|
// If it's 'else if', it contributes payloads recursively.
|
|
if (auto elseIfStmt = dyn_cast<IfStmt>(elseStmt)) {
|
|
return isBuildableIfChainRecursive(elseIfStmt, numPayloads, isOptional);
|
|
// Otherwise it's just the one.
|
|
} else {
|
|
++numPayloads;
|
|
}
|
|
|
|
// If not, the chain result is at least optional.
|
|
} else {
|
|
isOptional = true;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool hasUnconditionalElse(IfStmt *ifStmt) {
|
|
if (auto *elseStmt = ifStmt->getElseStmt()) {
|
|
if (auto *ifStmt = dyn_cast<IfStmt>(elseStmt))
|
|
return hasUnconditionalElse(ifStmt);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool isBuildableIfChain(IfStmt *ifStmt, unsigned &numPayloads,
|
|
bool &isOptional) {
|
|
if (!isBuildableIfChainRecursive(ifStmt, numPayloads, isOptional))
|
|
return false;
|
|
|
|
// If there's a missing 'else', we need 'buildOptional' to exist.
|
|
if (isOptional && !builder.supportsOptional())
|
|
return false;
|
|
|
|
// If there are multiple clauses, we need 'buildEither(first:)' and
|
|
// 'buildEither(second:)' to both exist.
|
|
if (numPayloads > 1) {
|
|
if (!builder.supports(ctx.Id_buildEither, {ctx.Id_first}) ||
|
|
!builder.supports(ctx.Id_buildEither, {ctx.Id_second}))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/// Wrap a payload value in an expression which will produce a chain
|
|
/// result (without `buildIf`).
|
|
Expr *buildWrappedChainPayload(Expr *operand, unsigned payloadIndex,
|
|
unsigned numPayloads, bool isOptional) {
|
|
assert(payloadIndex < numPayloads);
|
|
|
|
// Inject into the appropriate chain position.
|
|
//
|
|
// We produce a (left-biased) balanced binary tree of Eithers in order
|
|
// to prevent requiring a linear number of injections in the worst case.
|
|
// That is, if we have 13 clauses, we want to produce:
|
|
//
|
|
// /------------------Either------------\
|
|
// /-------Either-------\ /--Either--\
|
|
// /--Either--\ /--Either--\ /--Either--\ \
|
|
// /-E-\ /-E-\ /-E-\ /-E-\ /-E-\ /-E-\ \
|
|
// 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100
|
|
//
|
|
// Note that a prefix of length D of the payload index acts as a path
|
|
// through the tree to the node at depth D. On the rightmost path
|
|
// through the tree (when this prefix is equal to the corresponding
|
|
// prefix of the maximum payload index), the bits of the index mark
|
|
// where Eithers are required.
|
|
//
|
|
// Since we naturally want to build from the innermost Either out, and
|
|
// therefore work with progressively shorter prefixes, we can do it all
|
|
// with right-shifts.
|
|
for (auto path = payloadIndex, maxPath = numPayloads - 1; maxPath != 0;
|
|
path >>= 1, maxPath >>= 1) {
|
|
// Skip making Eithers on the rightmost path where they aren't required.
|
|
// This isn't just an optimization: adding spurious Eithers could
|
|
// leave us with unresolvable type variables if `buildEither` has
|
|
// a signature like:
|
|
// static func buildEither<T,U>(first value: T) -> Either<T,U>
|
|
// which relies on unification to work.
|
|
if (path == maxPath && !(maxPath & 1))
|
|
continue;
|
|
|
|
bool isSecond = (path & 1);
|
|
operand =
|
|
builder.buildCall(operand->getStartLoc(), ctx.Id_buildEither, operand,
|
|
{isSecond ? ctx.Id_second : ctx.Id_first});
|
|
}
|
|
|
|
// Inject into Optional if required. We'll be adding the call to
|
|
// `buildIf` after all the recursive calls are complete.
|
|
if (isOptional) {
|
|
operand = buildSomeExpr(operand);
|
|
}
|
|
|
|
return operand;
|
|
}
|
|
|
|
Expr *buildSomeExpr(Expr *arg) {
|
|
auto optionalDecl = ctx.getOptionalDecl();
|
|
auto optionalType = optionalDecl->getDeclaredType();
|
|
|
|
auto loc = arg->getStartLoc();
|
|
auto optionalTypeExpr =
|
|
TypeExpr::createImplicitHack(loc, optionalType, ctx);
|
|
auto someRef = new (ctx) UnresolvedDotExpr(
|
|
optionalTypeExpr, loc, DeclNameRef(ctx.getIdentifier("some")),
|
|
DeclNameLoc(loc), /*implicit=*/true);
|
|
auto *argList = ArgumentList::forImplicitUnlabeled(ctx, {arg});
|
|
return CallExpr::createImplicit(ctx, someRef, argList);
|
|
}
|
|
|
|
Expr *buildNoneExpr(SourceLoc endLoc) {
|
|
auto optionalDecl = ctx.getOptionalDecl();
|
|
auto optionalType = optionalDecl->getDeclaredType();
|
|
|
|
auto optionalTypeExpr =
|
|
TypeExpr::createImplicitHack(endLoc, optionalType, ctx);
|
|
return new (ctx) UnresolvedDotExpr(optionalTypeExpr, endLoc,
|
|
DeclNameRef(ctx.getIdentifier("none")),
|
|
DeclNameLoc(endLoc), /*implicit=*/true);
|
|
}
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
std::optional<BraceStmt *>
|
|
TypeChecker::applyResultBuilderBodyTransform(FuncDecl *func, Type builderType) {
|
|
// First look for any return statements, and bail if we have any.
|
|
auto &ctx = func->getASTContext();
|
|
if (evaluateOrDefault(ctx.evaluator, BraceHasReturnRequest{func->getBody()},
|
|
false)) {
|
|
// One or more explicit 'return' statements were encountered, which
|
|
// disables the result builder transform. Warn when we do this.
|
|
auto returnStmts = findReturnStatements(func);
|
|
assert(!returnStmts.empty());
|
|
|
|
ctx.Diags.diagnose(
|
|
returnStmts.front()->getReturnLoc(),
|
|
diag::result_builder_disabled_by_return_warn, builderType);
|
|
|
|
// Note that one can remove the result builder attribute.
|
|
auto attr = func->getAttachedResultBuilder();
|
|
if (!attr) {
|
|
if (auto accessor = dyn_cast<AccessorDecl>(func)) {
|
|
attr = accessor->getStorage()->getAttachedResultBuilder();
|
|
}
|
|
}
|
|
|
|
if (attr) {
|
|
diagnoseAndRemoveAttr(func, attr, diag::result_builder_remove_attr);
|
|
}
|
|
|
|
// Note that one can remove all of the return statements.
|
|
{
|
|
auto diag = ctx.Diags.diagnose(
|
|
returnStmts.front()->getReturnLoc(),
|
|
diag::result_builder_remove_returns);
|
|
for (auto returnStmt : returnStmts) {
|
|
diag.fixItRemove(returnStmt->getReturnLoc());
|
|
}
|
|
}
|
|
|
|
return std::nullopt;
|
|
}
|
|
|
|
auto target = SyntacticElementTarget(func);
|
|
if (ConstraintSystem::preCheckTarget(target))
|
|
return nullptr;
|
|
|
|
ConstraintSystemOptions options = ConstraintSystemFlags::AllowFixes;
|
|
auto resultInterfaceTy = func->getResultInterfaceType();
|
|
auto resultContextType = func->mapTypeIntoContext(resultInterfaceTy);
|
|
|
|
// Determine whether we're inferring the underlying type for the opaque
|
|
// result type of this function.
|
|
ConstraintKind resultConstraintKind = ConstraintKind::Conversion;
|
|
if (auto opaque = resultContextType->getAs<OpaqueTypeArchetypeType>()) {
|
|
if (opaque->getDecl()->isOpaqueReturnTypeOfFunction(func)) {
|
|
resultConstraintKind = ConstraintKind::Equal;
|
|
}
|
|
}
|
|
|
|
// Build a constraint system in which we can check the body of the function.
|
|
ConstraintSystem cs(func, options);
|
|
|
|
if (cs.isDebugMode()) {
|
|
auto &log = llvm::errs();
|
|
|
|
log << "--- Applying result builder to function ---\n";
|
|
func->dump(log);
|
|
log << '\n';
|
|
}
|
|
|
|
// Map type parameters into context. We don't want type
|
|
// parameters to appear in the result builder type, because
|
|
// the result builder type will only be used inside the body
|
|
// of this decl; it's not part of the interface type.
|
|
builderType = func->mapTypeIntoContext(builderType);
|
|
|
|
if (auto result = cs.matchResultBuilder(
|
|
func, builderType, resultContextType, resultConstraintKind,
|
|
/*contextualType=*/Type(),
|
|
cs.getConstraintLocator(func->getBody()))) {
|
|
if (result->isFailure())
|
|
return nullptr;
|
|
}
|
|
|
|
// Solve the constraint system.
|
|
if (cs.getASTContext().CompletionCallback) {
|
|
SmallVector<Solution, 4> solutions;
|
|
cs.Options |= ConstraintSystemFlags::AllowFixes;
|
|
cs.Options |= ConstraintSystemFlags::SuppressDiagnostics;
|
|
cs.Options |= ConstraintSystemFlags::ForCodeCompletion;
|
|
cs.solveForCodeCompletion(solutions);
|
|
|
|
CompletionContextFinder analyzer(target, func->getDeclContext());
|
|
if (analyzer.hasCompletion()) {
|
|
filterSolutionsForCodeCompletion(solutions, analyzer);
|
|
for (const auto &solution : solutions) {
|
|
cs.getASTContext().CompletionCallback->sawSolution(solution);
|
|
}
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
SmallVector<Solution, 4> solutions;
|
|
bool solvingFailed = cs.solve(solutions);
|
|
|
|
auto reportSolutionsToSolutionCallback = [&](const SolutionResult &result) {
|
|
if (!cs.getASTContext().SolutionCallback) {
|
|
return;
|
|
}
|
|
switch (result.getKind()) {
|
|
case SolutionResult::Success:
|
|
cs.getASTContext().SolutionCallback->sawSolution(result.getSolution());
|
|
break;
|
|
case SolutionResult::Ambiguous:
|
|
for (auto &solution : result.getAmbiguousSolutions()) {
|
|
cs.getASTContext().SolutionCallback->sawSolution(solution);
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
};
|
|
|
|
if (solvingFailed || solutions.size() != 1) {
|
|
// Try to fix the system or provide a decent diagnostic.
|
|
auto salvagedResult = cs.salvage();
|
|
switch (salvagedResult.getKind()) {
|
|
case SolutionResult::Kind::Success:
|
|
solutions.clear();
|
|
solutions.push_back(std::move(salvagedResult).takeSolution());
|
|
break;
|
|
|
|
case SolutionResult::Kind::Error:
|
|
case SolutionResult::Kind::Ambiguous:
|
|
reportSolutionsToSolutionCallback(salvagedResult);
|
|
return nullptr;
|
|
|
|
case SolutionResult::Kind::UndiagnosedError:
|
|
reportSolutionsToSolutionCallback(salvagedResult);
|
|
cs.diagnoseFailureFor(target);
|
|
salvagedResult.markAsDiagnosed();
|
|
return nullptr;
|
|
|
|
case SolutionResult::Kind::TooComplex:
|
|
reportSolutionsToSolutionCallback(salvagedResult);
|
|
func->diagnose(diag::expression_too_complex)
|
|
.highlight(func->getBodySourceRange());
|
|
salvagedResult.markAsDiagnosed();
|
|
return nullptr;
|
|
}
|
|
|
|
// The system was salvaged; continue on as if nothing happened.
|
|
}
|
|
|
|
if (cs.isDebugMode()) {
|
|
auto indent = cs.solverState ? cs.solverState->getCurrentIndent() : 0;
|
|
auto &log = llvm::errs().indent(indent);
|
|
log << "--- Applying Solution ---\n";
|
|
solutions.front().dump(log, indent);
|
|
log << '\n';
|
|
}
|
|
|
|
if (cs.getASTContext().SolutionCallback) {
|
|
for (auto &solution : solutions) {
|
|
cs.getASTContext().SolutionCallback->sawSolution(solution);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
// FIXME: Shouldn't need to do this.
|
|
cs.applySolution(solutions.front());
|
|
|
|
// Apply the solution to the function body.
|
|
if (auto result = cs.applySolution(solutions.front(), target)) {
|
|
performSyntacticDiagnosticsForTarget(*result, /*isExprStmt*/ false);
|
|
auto *body = result->getFunctionBody();
|
|
|
|
if (cs.isDebugMode()) {
|
|
auto indent = cs.solverState ? cs.solverState->getCurrentIndent() : 0;
|
|
auto &log = llvm::errs().indent(indent);
|
|
log << "--- Type-checked function body ---\n";
|
|
body->dump(log);
|
|
log << '\n';
|
|
}
|
|
|
|
return body;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
std::optional<ConstraintSystem::TypeMatchResult>
|
|
ConstraintSystem::matchResultBuilder(AnyFunctionRef fn, Type builderType,
|
|
Type bodyResultType,
|
|
ConstraintKind bodyResultConstraintKind,
|
|
Type contextualType,
|
|
ConstraintLocatorBuilder locator) {
|
|
builderType = simplifyType(builderType);
|
|
auto builder = builderType->getAnyNominal();
|
|
assert(builder && "Bad result builder type");
|
|
assert(builder->getAttrs().hasAttribute<ResultBuilderAttr>());
|
|
assert(!builderType->hasTypeParameter());
|
|
|
|
if (InvalidResultBuilderBodies.count(fn)) {
|
|
(void)recordFix(IgnoreInvalidResultBuilderBody::create(
|
|
*this, getConstraintLocator(fn.getAbstractClosureExpr())));
|
|
return getTypeMatchSuccess();
|
|
}
|
|
|
|
// We have already pre-checked the result builder body. Technically, we
|
|
// shouldn't need to do anything here, but there was a bug here that we did
|
|
// not apply the result builder transform if it contained an explicit return.
|
|
// To maintain source compatibility, we still need to check for HasReturnStmt.
|
|
// https://github.com/apple/swift/issues/64332.
|
|
if (evaluateOrDefault(getASTContext().evaluator,
|
|
BraceHasReturnRequest{fn.getBody()}, false)) {
|
|
// Diagnostic mode means that solver couldn't reach any viable
|
|
// solution, so let's diagnose presence of a `return` statement
|
|
// in the closure body.
|
|
if (shouldAttemptFixes()) {
|
|
if (recordFix(IgnoreResultBuilderWithReturnStmts::create(
|
|
*this, builderType,
|
|
getConstraintLocator(fn.getAbstractClosureExpr()))))
|
|
return getTypeMatchFailure(locator);
|
|
|
|
return getTypeMatchSuccess();
|
|
}
|
|
|
|
// If the body has a return statement, suppress the transform but
|
|
// continue solving the constraint system.
|
|
return std::nullopt;
|
|
}
|
|
|
|
auto transformedBody = getBuilderTransformedBody(fn, builder);
|
|
// If this builder transform has not yet been applied to this function,
|
|
// let's do it and cache the result.
|
|
if (!transformedBody) {
|
|
ResultBuilderTransform transform(*this, fn.getAsDeclContext(),
|
|
fn.getBody()->getSourceRange(),
|
|
builderType, bodyResultType);
|
|
auto *body = transform.apply(fn.getBody());
|
|
|
|
if (auto unsupported = transform.getUnsupportedElement()) {
|
|
assert(!body || getASTContext().CompletionCallback);
|
|
|
|
// If we aren't supposed to attempt fixes, fail.
|
|
if (!shouldAttemptFixes()) {
|
|
return getTypeMatchFailure(locator);
|
|
}
|
|
|
|
// If we're solving for code completion and the body contains the code
|
|
// completion location, skipping it won't get us to a useful solution so
|
|
// just bail.
|
|
if (isForCodeCompletion() &&
|
|
containsIDEInspectionTarget(fn.getBody())) {
|
|
return getTypeMatchFailure(locator);
|
|
}
|
|
|
|
// Record the first unhandled construct as a fix.
|
|
if (recordFix(
|
|
SkipUnhandledConstructInResultBuilder::create(
|
|
*this, unsupported, builder, getConstraintLocator(locator)),
|
|
/*impact=*/100)) {
|
|
return getTypeMatchFailure(locator);
|
|
}
|
|
|
|
if (auto *closure =
|
|
getAsExpr<ClosureExpr>(fn.getAbstractClosureExpr())) {
|
|
recordTypeVariablesAsHoles(getClosureType(closure));
|
|
}
|
|
|
|
return getTypeMatchSuccess();
|
|
}
|
|
|
|
transformedBody = std::make_pair(transform.getBuilderSelf(), body);
|
|
// Record the transformation so it could be re-used if needed.
|
|
setBuilderTransformedBody(fn, builder, transformedBody->first,
|
|
transformedBody->second);
|
|
}
|
|
|
|
// Set the type of `$__builderSelf` variable before constraint generation.
|
|
setType(transformedBody->first, MetatypeType::get(builderType));
|
|
|
|
if (isDebugMode()) {
|
|
auto &log = llvm::errs();
|
|
auto indent = solverState ? solverState->getCurrentIndent() : 0;
|
|
log.indent(indent) << "------- Transformed Body -------\n";
|
|
transformedBody->second->dump(log, &getASTContext(), indent);
|
|
log << '\n';
|
|
}
|
|
|
|
AppliedBuilderTransform transformInfo;
|
|
|
|
transformInfo.builderType = builderType;
|
|
transformInfo.bodyResultType = bodyResultType;
|
|
transformInfo.contextualType = contextualType;
|
|
transformInfo.transformedBody = transformedBody->second;
|
|
|
|
// Record the transformation.
|
|
assert(
|
|
std::find_if(
|
|
resultBuilderTransformed.begin(), resultBuilderTransformed.end(),
|
|
[&](const std::pair<AnyFunctionRef, AppliedBuilderTransform> &elt) {
|
|
return elt.first == fn;
|
|
}) == resultBuilderTransformed.end() &&
|
|
"already transformed this body along this path!?!");
|
|
resultBuilderTransformed.insert(
|
|
std::make_pair(fn, std::move(transformInfo)));
|
|
|
|
if (generateConstraints(fn, transformInfo.transformedBody))
|
|
return getTypeMatchFailure(locator);
|
|
|
|
return getTypeMatchSuccess();
|
|
}
|
|
|
|
namespace {
|
|
class ReturnStmtFinder : public ASTWalker {
|
|
std::vector<ReturnStmt *> ReturnStmts;
|
|
|
|
public:
|
|
static std::vector<ReturnStmt *> find(const BraceStmt *BS) {
|
|
ReturnStmtFinder finder;
|
|
const_cast<BraceStmt *>(BS)->walk(finder);
|
|
return std::move(finder.ReturnStmts);
|
|
}
|
|
|
|
MacroWalking getMacroWalkingBehavior() const override {
|
|
return MacroWalking::Arguments;
|
|
}
|
|
|
|
PreWalkResult<Expr *> walkToExprPre(Expr *E) override {
|
|
return Action::SkipNode(E);
|
|
}
|
|
|
|
PreWalkResult<Stmt *> walkToStmtPre(Stmt *S) override {
|
|
// If we see a return statement, note it..
|
|
auto *returnStmt = dyn_cast<ReturnStmt>(S);
|
|
if (!returnStmt || returnStmt->isImplicit())
|
|
return Action::Continue(S);
|
|
|
|
ReturnStmts.push_back(returnStmt);
|
|
return Action::SkipNode(S);
|
|
}
|
|
|
|
/// Ignore patterns.
|
|
PreWalkResult<Pattern *> walkToPatternPre(Pattern *pat) override {
|
|
return Action::SkipNode(pat);
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
bool BraceHasReturnRequest::evaluate(Evaluator &evaluator,
|
|
const BraceStmt *BS) const {
|
|
return !ReturnStmtFinder::find(BS).empty();
|
|
}
|
|
|
|
std::vector<ReturnStmt *> TypeChecker::findReturnStatements(AnyFunctionRef fn) {
|
|
return ReturnStmtFinder::find(fn.getBody());
|
|
}
|
|
|
|
ResultBuilderOpSupport TypeChecker::checkBuilderOpSupport(
|
|
Type builderType, DeclContext *dc, Identifier fnName,
|
|
ArrayRef<Identifier> argLabels, SmallVectorImpl<ValueDecl *> *allResults) {
|
|
|
|
auto isUnavailable = [&](Decl *D) -> bool {
|
|
if (AvailableAttr::isUnavailable(D))
|
|
return true;
|
|
|
|
auto loc = extractNearestSourceLoc(dc);
|
|
auto context = ExportContext::forFunctionBody(dc, loc);
|
|
return TypeChecker::checkDeclarationAvailability(D, context).has_value();
|
|
};
|
|
|
|
bool foundMatch = false;
|
|
bool foundUnavailable = false;
|
|
|
|
SmallVector<ValueDecl *, 4> foundDecls;
|
|
dc->lookupQualified(
|
|
builderType, DeclNameRef(fnName),
|
|
builderType->getAnyNominal()->getLoc(),
|
|
NL_QualifiedDefault | NL_ProtocolMembers, foundDecls);
|
|
for (auto decl : foundDecls) {
|
|
if (auto func = dyn_cast<FuncDecl>(decl)) {
|
|
// Function must be static.
|
|
if (!func->isStatic())
|
|
continue;
|
|
|
|
// Function must have the right argument labels, if provided.
|
|
if (!argLabels.empty()) {
|
|
auto funcLabels = func->getName().getArgumentNames();
|
|
if (argLabels.size() > funcLabels.size() ||
|
|
funcLabels.slice(0, argLabels.size()) != argLabels)
|
|
continue;
|
|
}
|
|
|
|
// Check if the candidate has a suitable availability for the
|
|
// calling context.
|
|
if (isUnavailable(func)) {
|
|
foundUnavailable = true;
|
|
continue;
|
|
}
|
|
foundMatch = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (allResults)
|
|
allResults->append(foundDecls.begin(), foundDecls.end());
|
|
|
|
if (!foundMatch) {
|
|
return foundUnavailable ? ResultBuilderOpSupport::Unavailable
|
|
: ResultBuilderOpSupport::Unsupported;
|
|
}
|
|
// If the builder type itself isn't available, don't consider any builder
|
|
// method available.
|
|
if (auto *D = builderType->getAnyNominal()) {
|
|
if (isUnavailable(D))
|
|
return ResultBuilderOpSupport::Unavailable;
|
|
}
|
|
return ResultBuilderOpSupport::Supported;
|
|
}
|
|
|
|
bool TypeChecker::typeSupportsBuilderOp(
|
|
Type builderType, DeclContext *dc, Identifier fnName,
|
|
ArrayRef<Identifier> argLabels, SmallVectorImpl<ValueDecl *> *allResults) {
|
|
return checkBuilderOpSupport(builderType, dc, fnName, argLabels, allResults)
|
|
.isSupported(/*requireAvailable*/ false);
|
|
}
|
|
|
|
Type swift::inferResultBuilderComponentType(NominalTypeDecl *builder) {
|
|
Type componentType;
|
|
|
|
SmallVector<ValueDecl *, 4> potentialMatches;
|
|
ASTContext &ctx = builder->getASTContext();
|
|
bool supportsBuildBlock = TypeChecker::typeSupportsBuilderOp(
|
|
builder->getDeclaredInterfaceType(), builder, ctx.Id_buildBlock,
|
|
/*argLabels=*/{}, &potentialMatches);
|
|
if (supportsBuildBlock) {
|
|
for (auto decl : potentialMatches) {
|
|
auto func = dyn_cast<FuncDecl>(decl);
|
|
if (!func || !func->isStatic())
|
|
continue;
|
|
|
|
// If we haven't seen a component type before, gather it.
|
|
if (!componentType) {
|
|
componentType = func->getResultInterfaceType();
|
|
continue;
|
|
}
|
|
|
|
// If there are inconsistent component types, bail out.
|
|
if (!componentType->isEqual(func->getResultInterfaceType())) {
|
|
componentType = Type();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return componentType;
|
|
}
|
|
|
|
std::tuple<SourceLoc, std::string, Type>
|
|
swift::determineResultBuilderBuildFixItInfo(NominalTypeDecl *builder) {
|
|
SourceLoc buildInsertionLoc = builder->getBraces().Start;
|
|
std::string stubIndent;
|
|
Type componentType;
|
|
|
|
if (buildInsertionLoc.isInvalid())
|
|
return std::make_tuple(buildInsertionLoc, stubIndent, componentType);
|
|
|
|
ASTContext &ctx = builder->getASTContext();
|
|
buildInsertionLoc = Lexer::getLocForEndOfToken(
|
|
ctx.SourceMgr, buildInsertionLoc);
|
|
|
|
StringRef extraIndent;
|
|
StringRef currentIndent = Lexer::getIndentationForLine(
|
|
ctx.SourceMgr, buildInsertionLoc, &extraIndent);
|
|
stubIndent = (currentIndent + extraIndent).str();
|
|
|
|
componentType = inferResultBuilderComponentType(builder);
|
|
return std::make_tuple(buildInsertionLoc, stubIndent, componentType);
|
|
}
|
|
|
|
void swift::printResultBuilderBuildFunction(
|
|
NominalTypeDecl *builder, Type componentType,
|
|
ResultBuilderBuildFunction function, std::optional<std::string> stubIndent,
|
|
llvm::raw_ostream &out) {
|
|
// Render the component type into a string.
|
|
std::string componentTypeString;
|
|
if (componentType)
|
|
componentTypeString = componentType.getString();
|
|
else
|
|
componentTypeString = "<#Component#>";
|
|
|
|
// Render the code.
|
|
std::string stubIndentStr = stubIndent.value_or(std::string());
|
|
ExtraIndentStreamPrinter printer(out, stubIndentStr);
|
|
|
|
// If we're supposed to provide a full stub, add a newline and the introducer
|
|
// keywords.
|
|
if (stubIndent) {
|
|
printer.printNewline();
|
|
|
|
if (builder->getFormalAccess() >= AccessLevel::Public)
|
|
printer << "public ";
|
|
|
|
printer << "static func ";
|
|
}
|
|
|
|
bool printedResult = false;
|
|
switch (function) {
|
|
case ResultBuilderBuildFunction::BuildBlock:
|
|
printer << "buildBlock(_ components: " << componentTypeString << "...)";
|
|
break;
|
|
|
|
case ResultBuilderBuildFunction::BuildExpression:
|
|
printer << "buildExpression(_ expression: <#Expression#>)";
|
|
break;
|
|
|
|
case ResultBuilderBuildFunction::BuildOptional:
|
|
printer << "buildOptional(_ component: " << componentTypeString << "?)";
|
|
break;
|
|
|
|
case ResultBuilderBuildFunction::BuildEitherFirst:
|
|
printer << "buildEither(first component: " << componentTypeString << ")";
|
|
break;
|
|
|
|
case ResultBuilderBuildFunction::BuildEitherSecond:
|
|
printer << "buildEither(second component: " << componentTypeString << ")";
|
|
break;
|
|
|
|
case ResultBuilderBuildFunction::BuildArray:
|
|
printer << "buildArray(_ components: [" << componentTypeString << "])";
|
|
break;
|
|
|
|
case ResultBuilderBuildFunction::BuildLimitedAvailability:
|
|
printer << "buildLimitedAvailability(_ component: " << componentTypeString
|
|
<< ")";
|
|
break;
|
|
|
|
case ResultBuilderBuildFunction::BuildFinalResult:
|
|
printer << "buildFinalResult(_ component: " << componentTypeString
|
|
<< ") -> <#Result#>";
|
|
printedResult = true;
|
|
break;
|
|
case ResultBuilderBuildFunction::BuildPartialBlockFirst:
|
|
printer << "buildPartialBlock(first: " << componentTypeString << ")";
|
|
break;
|
|
case ResultBuilderBuildFunction::BuildPartialBlockAccumulated:
|
|
printer << "buildPartialBlock(accumulated: " << componentTypeString
|
|
<< ", next: " << componentTypeString << ")";
|
|
break;
|
|
}
|
|
|
|
if (!printedResult)
|
|
printer << " -> " << componentTypeString;
|
|
|
|
if (stubIndent) {
|
|
printer << " {";
|
|
printer.printNewline();
|
|
printer << " <#code#>";
|
|
printer.printNewline();
|
|
printer << "}";
|
|
}
|
|
}
|
|
|
|
ResultBuilder::ResultBuilder(ConstraintSystem &CS, DeclContext *DC,
|
|
Type builderType)
|
|
: DC(DC), BuilderType(CS.simplifyType(builderType)) {
|
|
auto &ctx = DC->getASTContext();
|
|
// Use buildOptional(_:) if available, otherwise fall back to buildIf
|
|
// when available.
|
|
BuildOptionalId =
|
|
(supports(ctx.Id_buildOptional) || !supports(ctx.Id_buildIf))
|
|
? ctx.Id_buildOptional
|
|
: ctx.Id_buildIf;
|
|
|
|
BuilderSelf = new (ctx) VarDecl(
|
|
/*isStatic=*/false, VarDecl::Introducer::Let,
|
|
/*nameLoc=*/SourceLoc(), ctx.Id_builderSelf, DC);
|
|
BuilderSelf->setImplicit();
|
|
CS.setType(BuilderSelf, MetatypeType::get(BuilderType));
|
|
}
|
|
|
|
bool ResultBuilder::supportsBuildPartialBlock(bool checkAvailability) {
|
|
auto &ctx = DC->getASTContext();
|
|
return supports(ctx.Id_buildPartialBlock, {ctx.Id_first},
|
|
checkAvailability) &&
|
|
supports(ctx.Id_buildPartialBlock, {ctx.Id_accumulated, ctx.Id_next},
|
|
checkAvailability);
|
|
}
|
|
|
|
bool ResultBuilder::canUseBuildPartialBlock() {
|
|
// If buildPartialBlock doesn't exist at all, we can't use it.
|
|
if (!supportsBuildPartialBlock(/*checkAvailability*/ false))
|
|
return false;
|
|
|
|
// If buildPartialBlock exists and is available, use it.
|
|
if (supportsBuildPartialBlock(/*checkAvailability*/ true))
|
|
return true;
|
|
|
|
// We have buildPartialBlock, but it is unavailable. We can however still
|
|
// use it if buildBlock is also unavailable.
|
|
auto &ctx = DC->getASTContext();
|
|
return supports(ctx.Id_buildBlock) &&
|
|
!supports(ctx.Id_buildBlock, /*labels*/ {},
|
|
/*checkAvailability*/ true);
|
|
}
|
|
|
|
bool ResultBuilder::supports(Identifier fnBaseName,
|
|
ArrayRef<Identifier> argLabels,
|
|
bool checkAvailability) {
|
|
DeclName name(DC->getASTContext(), fnBaseName, argLabels);
|
|
auto known = SupportedOps.find(name);
|
|
if (known != SupportedOps.end())
|
|
return known->second.isSupported(checkAvailability);
|
|
|
|
auto support = TypeChecker::checkBuilderOpSupport(
|
|
BuilderType, DC, fnBaseName, argLabels, /*allResults*/ {});
|
|
SupportedOps.insert({name, support});
|
|
return support.isSupported(checkAvailability);
|
|
}
|
|
|
|
Expr *ResultBuilder::buildCall(SourceLoc loc, Identifier fnName,
|
|
ArrayRef<Expr *> argExprs,
|
|
ArrayRef<Identifier> argLabels) const {
|
|
assert(BuilderSelf);
|
|
|
|
auto &ctx = DC->getASTContext();
|
|
|
|
SmallVector<Argument, 4> args;
|
|
for (auto i : indices(argExprs)) {
|
|
auto *expr = argExprs[i];
|
|
auto label = argLabels.empty() ? Identifier() : argLabels[i];
|
|
auto labelLoc = argLabels.empty() ? SourceLoc() : expr->getStartLoc();
|
|
args.emplace_back(labelLoc, label, expr);
|
|
}
|
|
|
|
auto *baseExpr = new (ctx) DeclRefExpr({BuilderSelf}, DeclNameLoc(loc),
|
|
/*isImplicit=*/true);
|
|
|
|
auto memberRef = new (ctx)
|
|
UnresolvedDotExpr(baseExpr, loc, DeclNameRef(fnName), DeclNameLoc(loc),
|
|
/*implicit=*/true);
|
|
memberRef->setFunctionRefKind(FunctionRefKind::SingleApply);
|
|
|
|
auto openLoc = args.empty() ? loc : argExprs.front()->getStartLoc();
|
|
auto closeLoc = args.empty() ? loc : argExprs.back()->getEndLoc();
|
|
|
|
auto *argList = ArgumentList::createImplicit(ctx, openLoc, args, closeLoc);
|
|
return CallExpr::createImplicit(ctx, memberRef, argList);
|
|
}
|
|
|
|
VarDecl *ResultBuilder::buildVar(SourceLoc loc) {
|
|
auto &ctx = DC->getASTContext();
|
|
// Create the implicit variable.
|
|
Identifier name =
|
|
ctx.getIdentifier(("$__builder" + Twine(VarCounter++)).str());
|
|
auto var = new (ctx)
|
|
VarDecl(/*isStatic=*/false, VarDecl::Introducer::Var, loc, name, DC);
|
|
var->setImplicit();
|
|
return var;
|
|
}
|
|
|
|
DeclRefExpr *ResultBuilder::buildVarRef(VarDecl *var, SourceLoc loc) {
|
|
return new (DC->getASTContext())
|
|
DeclRefExpr(var, DeclNameLoc(loc), /*Implicit=*/true);
|
|
}
|