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Desugar.cc
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#include <algorithm>
#include "absl/strings/numbers.h"
#include "absl/strings/str_replace.h"
#include "ast/Helpers.h"
#include "ast/ast.h"
#include "ast/desugar/Desugar.h"
#include "ast/verifier/verifier.h"
#include "common/common.h"
#include "common/formatting.h"
#include "core/Names.h"
#include "core/errors/desugar.h"
#include "core/errors/internal.h"
namespace sorbet::ast::desugar {
using namespace std;
namespace {
struct DesugarContext final {
core::MutableContext ctx;
uint32_t &uniqueCounter;
core::NameRef enclosingBlockArg;
core::LocOffsets enclosingMethodLoc;
core::NameRef enclosingMethodName;
DesugarContext(core::MutableContext ctx, uint32_t &uniqueCounter, core::NameRef enclosingBlockArg,
core::LocOffsets enclosingMethodLoc, core::NameRef enclosingMethodName)
: ctx(ctx), uniqueCounter(uniqueCounter), enclosingBlockArg(enclosingBlockArg),
enclosingMethodLoc(enclosingMethodLoc), enclosingMethodName(enclosingMethodName){};
core::NameRef freshNameUnique(core::NameRef name) {
return ctx.state.freshNameUnique(core::UniqueNameKind::Desugar, name, ++uniqueCounter);
}
};
core::NameRef blockArg2Name(DesugarContext dctx, const BlockArg &blkArg) {
auto blkIdent = cast_tree<UnresolvedIdent>(blkArg.expr);
ENFORCE(blkIdent != nullptr, "BlockArg must wrap UnresolvedIdent in desugar.");
return blkIdent->name;
}
// Get the num from the name of the Node if it's a LVar.
// Return -1 otherwise.
int numparamNum(DesugarContext dctx, parser::Node *decl) {
if (auto *lvar = parser::cast_node<parser::LVar>(decl)) {
auto name_str = lvar->name.show(dctx.ctx);
return name_str[1] - 48;
}
return -1;
}
// Get the highest numparams used in `decls`
// Return 0 if the list of declarations is empty.
int numparamMax(DesugarContext dctx, parser::NodeVec *decls) {
int max = 0;
for (auto &decl : *decls) {
auto num = numparamNum(dctx, decl.get());
if (num > max) {
max = num;
}
}
return max;
}
// Create a local variable from the first declaration for the name "_num" from all the `decls` if any.
// Return a dummy variable if no declaration is found for `num`.
ExpressionPtr numparamTree(DesugarContext dctx, int num, parser::NodeVec *decls) {
for (auto &decl : *decls) {
if (auto *lvar = parser::cast_node<parser::LVar>(decl.get())) {
if (numparamNum(dctx, decl.get()) == num) {
return MK::Local(lvar->loc, lvar->name);
}
} else {
ENFORCE(false, "NumParams declaring node is not a LVar.");
}
}
core::NameRef name = dctx.ctx.state.enterNameUTF8("_" + std::to_string(num));
return MK::Local(core::LocOffsets::none(), name);
}
ExpressionPtr node2TreeImpl(DesugarContext dctx, unique_ptr<parser::Node> what);
pair<MethodDef::ARGS_store, InsSeq::STATS_store> desugarArgs(DesugarContext dctx, core::LocOffsets loc,
unique_ptr<parser::Node> &argnode) {
MethodDef::ARGS_store args;
InsSeq::STATS_store destructures;
if (auto *oargs = parser::cast_node<parser::Args>(argnode.get())) {
args.reserve(oargs->args.size());
for (auto &arg : oargs->args) {
if (auto *lhs = parser::cast_node<parser::Mlhs>(arg.get())) {
core::NameRef temporary = dctx.freshNameUnique(core::Names::destructureArg());
args.emplace_back(MK::Local(arg->loc, temporary));
unique_ptr<parser::Node> lvarNode = make_unique<parser::LVar>(arg->loc, temporary);
unique_ptr<parser::Node> destructure =
make_unique<parser::Masgn>(arg->loc, std::move(arg), std::move(lvarNode));
destructures.emplace_back(node2TreeImpl(dctx, std::move(destructure)));
} else if (auto *lhs = parser::cast_node<parser::Kwnilarg>(arg.get())) {
// TODO implement logic for `**nil` args
} else if (auto *fargs = parser::cast_node<parser::ForwardArg>(arg.get())) {
// we desugar (m, n, ...) into (m, n, *<fwd-args>, **<fwd-kwargs>, &<fwd-block>)
// add `*<fwd-args>`
unique_ptr<parser::Node> rest =
make_unique<parser::Restarg>(fargs->loc, core::Names::fwdArgs(), fargs->loc);
args.emplace_back(node2TreeImpl(dctx, std::move(rest)));
// add `**<fwd-kwargs>`
unique_ptr<parser::Node> kwrest = make_unique<parser::Kwrestarg>(fargs->loc, core::Names::fwdKwargs());
args.emplace_back(node2TreeImpl(dctx, std::move(kwrest)));
// add `&<fwd-block>`
unique_ptr<parser::Node> block = make_unique<parser::Blockarg>(fargs->loc, core::Names::fwdBlock());
args.emplace_back(node2TreeImpl(dctx, std::move(block)));
} else {
args.emplace_back(node2TreeImpl(dctx, std::move(arg)));
}
}
} else if (auto *numparams = parser::cast_node<parser::NumParams>(argnode.get())) {
// The block uses numbered parameters like `_1` or `_9` so we add them as parameters
// from _1 to the highest number used.
for (int i = 1; i <= numparamMax(dctx, &numparams->decls); i++) {
args.emplace_back(numparamTree(dctx, i, &numparams->decls));
}
} else if (argnode.get() == nullptr) {
// do nothing
} else {
Exception::raise("not implemented: {}", argnode->nodeName());
}
return make_pair(std::move(args), std::move(destructures));
}
ExpressionPtr desugarBody(DesugarContext dctx, core::LocOffsets loc, unique_ptr<parser::Node> &bodynode,
InsSeq::STATS_store destructures) {
auto body = node2TreeImpl(dctx, std::move(bodynode));
if (!destructures.empty()) {
auto bodyLoc = body.loc();
if (!bodyLoc.exists()) {
bodyLoc = loc;
}
body = MK::InsSeq(loc, std::move(destructures), std::move(body));
}
return body;
}
ExpressionPtr desugarBlock(DesugarContext dctx, core::LocOffsets loc, core::LocOffsets blockLoc,
unique_ptr<parser::Node> &blockSend, unique_ptr<parser::Node> &blockArgs,
unique_ptr<parser::Node> &blockBody) {
blockSend->loc = loc;
auto recv = node2TreeImpl(dctx, std::move(blockSend));
Send *send;
ExpressionPtr res;
if ((send = cast_tree<Send>(recv)) != nullptr) {
res = std::move(recv);
} else {
// This must have been a csend; That will have been desugared
// into an insseq with an If in the expression.
res = std::move(recv);
auto *is = cast_tree<InsSeq>(res);
if (!is) {
if (auto e = dctx.ctx.beginError(blockLoc, core::errors::Desugar::UnsupportedNode)) {
e.setHeader("No body in block");
}
return MK::EmptyTree();
}
auto *iff = cast_tree<If>(is->expr);
ENFORCE(iff != nullptr, "DesugarBlock: failed to find If");
send = cast_tree<Send>(iff->elsep);
ENFORCE(send != nullptr, "DesugarBlock: failed to find Send");
}
auto [args, destructures] = desugarArgs(dctx, loc, blockArgs);
auto desugaredBody = desugarBody(dctx, loc, blockBody, std::move(destructures));
// TODO the send->block's loc is too big and includes the whole send
send->setBlock(MK::Block(loc, std::move(desugaredBody), std::move(args)));
return res;
}
bool isStringLit(DesugarContext dctx, ExpressionPtr &expr) {
Literal *lit;
return (lit = cast_tree<Literal>(expr)) && lit->isString();
}
ExpressionPtr mergeStrings(DesugarContext dctx, core::LocOffsets loc,
InlinedVector<ExpressionPtr, 4> stringsAccumulated) {
if (stringsAccumulated.size() == 1) {
return move(stringsAccumulated[0]);
} else {
return MK::String(loc, dctx.ctx.state.enterNameUTF8(
fmt::format("{}", fmt::map_join(stringsAccumulated, "", [&](const auto &expr) {
if (isa_tree<EmptyTree>(expr)) {
return ""sv;
} else {
return cast_tree<Literal>(expr)->asString().shortName(dctx.ctx);
}
}))));
}
}
ExpressionPtr desugarDString(DesugarContext dctx, core::LocOffsets loc, parser::NodeVec nodes) {
if (nodes.empty()) {
return MK::String(loc, core::Names::empty());
}
auto it = nodes.begin();
auto end = nodes.end();
ExpressionPtr first = node2TreeImpl(dctx, std::move(*it));
InlinedVector<ExpressionPtr, 4> stringsAccumulated;
Send::ARGS_store interpArgs;
bool allStringsSoFar;
if (isStringLit(dctx, first) || isa_tree<EmptyTree>(first)) {
stringsAccumulated.emplace_back(std::move(first));
allStringsSoFar = true;
} else {
interpArgs.emplace_back(std::move(first));
allStringsSoFar = false;
}
++it;
for (; it != end; ++it) {
auto &stat = *it;
ExpressionPtr narg = node2TreeImpl(dctx, std::move(stat));
if (allStringsSoFar && isStringLit(dctx, narg)) {
stringsAccumulated.emplace_back(std::move(narg));
} else if (isa_tree<EmptyTree>(narg)) {
// no op
} else {
if (allStringsSoFar) {
allStringsSoFar = false;
interpArgs.emplace_back(mergeStrings(dctx, loc, std::move(stringsAccumulated)));
}
interpArgs.emplace_back(std::move(narg));
}
};
if (allStringsSoFar) {
return mergeStrings(dctx, loc, std::move(stringsAccumulated));
} else {
auto recv = MK::Magic(loc);
return MK::Send(loc, std::move(recv), core::Names::stringInterpolate(), loc.copyWithZeroLength(),
interpArgs.size(), std::move(interpArgs));
}
}
bool isIVarAssign(ExpressionPtr &stat) {
auto assign = cast_tree<Assign>(stat);
if (!assign) {
return false;
}
auto ident = cast_tree<UnresolvedIdent>(assign->lhs);
if (!ident) {
return false;
}
if (ident->kind != UnresolvedIdent::Kind::Instance) {
return false;
}
return true;
}
ExpressionPtr validateRBIBody(DesugarContext dctx, ExpressionPtr body) {
if (!dctx.ctx.file.data(dctx.ctx).isRBI()) {
return body;
}
if (!body.loc().exists()) {
return body;
}
auto loc = dctx.ctx.locAt(body.loc());
if (isa_tree<EmptyTree>(body)) {
return body;
} else if (isa_tree<Assign>(body)) {
if (!isIVarAssign(body)) {
if (auto e = dctx.ctx.beginError(body.loc(), core::errors::Desugar::CodeInRBI)) {
e.setHeader("RBI methods must not have code");
e.replaceWith("Delete the body", loc, "");
}
}
} else if (auto inseq = cast_tree<InsSeq>(body)) {
for (auto &stat : inseq->stats) {
if (!isIVarAssign(stat)) {
if (auto e = dctx.ctx.beginError(stat.loc(), core::errors::Desugar::CodeInRBI)) {
e.setHeader("RBI methods must not have code");
e.replaceWith("Delete the body", loc, "");
}
}
}
if (!isIVarAssign(inseq->expr)) {
if (auto e = dctx.ctx.beginError(inseq->expr.loc(), core::errors::Desugar::CodeInRBI)) {
e.setHeader("RBI methods must not have code");
e.replaceWith("Delete the body", loc, "");
}
}
} else {
if (auto e = dctx.ctx.beginError(body.loc(), core::errors::Desugar::CodeInRBI)) {
e.setHeader("RBI methods must not have code");
e.replaceWith("Delete the body", loc, "");
}
}
return body;
}
ExpressionPtr buildMethod(DesugarContext dctx, core::LocOffsets loc, core::LocOffsets declLoc, core::NameRef name,
unique_ptr<parser::Node> &argnode, unique_ptr<parser::Node> &body, bool isSelf) {
// Reset uniqueCounter within this scope (to keep numbers small)
uint32_t uniqueCounter = 1;
DesugarContext dctx1(dctx.ctx, uniqueCounter, dctx.enclosingBlockArg, declLoc, name);
auto [args, destructures] = desugarArgs(dctx1, loc, argnode);
if (args.empty() || !isa_tree<BlockArg>(args.back())) {
auto blkLoc = core::LocOffsets::none();
args.emplace_back(MK::BlockArg(blkLoc, MK::Local(blkLoc, core::Names::blkArg())));
}
const auto &blkArg = cast_tree<BlockArg>(args.back());
ENFORCE(blkArg != nullptr, "Every method's last arg must be a block arg by now.");
auto enclosingBlockArg = blockArg2Name(dctx, *blkArg);
DesugarContext dctx2(dctx1.ctx, dctx1.uniqueCounter, enclosingBlockArg, declLoc, name);
ExpressionPtr desugaredBody = desugarBody(dctx2, loc, body, std::move(destructures));
desugaredBody = validateRBIBody(dctx2, move(desugaredBody));
auto mdef = MK::Method(loc, declLoc, name, std::move(args), std::move(desugaredBody));
cast_tree<MethodDef>(mdef)->flags.isSelfMethod = isSelf;
return mdef;
}
ExpressionPtr symbol2Proc(DesugarContext dctx, ExpressionPtr expr) {
auto loc = expr.loc();
core::NameRef temp = dctx.freshNameUnique(core::Names::blockPassTemp());
Literal *lit = cast_tree<Literal>(expr);
ENFORCE(lit && lit->isSymbol());
// &:foo => {|*temp| (temp[0]).foo(*tmp[1, LONG_MAX]) }
core::NameRef name = core::cast_type_nonnull<core::NamedLiteralType>(lit->value).asName();
// `temp` does not refer to any specific source text, so give it a 0-length Loc so LSP ignores it.
auto zeroLengthLoc = loc.copyWithZeroLength();
auto recv = MK::Send1(zeroLengthLoc, MK::Local(zeroLengthLoc, temp), core::Names::squareBrackets(), zeroLengthLoc,
MK::Int(zeroLengthLoc, 0));
auto sliced = MK::Send2(zeroLengthLoc, MK::Local(zeroLengthLoc, temp), core::Names::squareBrackets(), zeroLengthLoc,
MK::Int(zeroLengthLoc, 1), MK::Int(zeroLengthLoc, LONG_MAX));
auto body = MK::CallWithSplat(loc, std::move(recv), name, zeroLengthLoc, MK::Splat(zeroLengthLoc, move(sliced)));
return MK::Block1(loc, std::move(body), MK::RestArg(zeroLengthLoc, MK::Local(zeroLengthLoc, temp)));
}
ExpressionPtr unsupportedNode(DesugarContext dctx, parser::Node *node) {
if (auto e = dctx.ctx.beginError(node->loc, core::errors::Desugar::UnsupportedNode)) {
e.setHeader("Unsupported node type `{}`", node->nodeName());
}
return MK::EmptyTree();
}
ExpressionPtr desugarMlhs(DesugarContext dctx, core::LocOffsets loc, parser::Mlhs *lhs, ExpressionPtr rhs) {
InsSeq::STATS_store stats;
core::NameRef tempRhs = dctx.freshNameUnique(core::Names::assignTemp());
core::NameRef tempExpanded = dctx.freshNameUnique(core::Names::assignTemp());
int i = 0;
int before = 0, after = 0;
bool didSplat = false;
for (auto &c : lhs->exprs) {
if (auto *splat = parser::cast_node<parser::SplatLhs>(c.get())) {
ENFORCE(!didSplat, "did splat already");
didSplat = true;
ExpressionPtr lh = node2TreeImpl(dctx, std::move(splat->var));
int left = i;
int right = lhs->exprs.size() - left - 1;
if (!isa_tree<EmptyTree>(lh)) {
auto exclusive = MK::True(lh.loc());
if (right == 0) {
right = 1;
exclusive = MK::False(lh.loc());
}
auto lhloc = lh.loc();
auto zlhloc = lhloc.copyWithZeroLength();
auto index = MK::Send3(lhloc, MK::Constant(lhloc, core::Symbols::Range()), core::Names::new_(), zlhloc,
MK::Int(lhloc, left), MK::Int(lhloc, -right), std::move(exclusive));
stats.emplace_back(MK::Assign(
lhloc, std::move(lh),
MK::Send1(loc, MK::Local(loc, tempExpanded), core::Names::slice(), zlhloc, std::move(index))));
}
i = -right;
} else {
if (didSplat) {
++after;
} else {
++before;
}
auto val = MK::Send1(loc, MK::Local(loc, tempExpanded), core::Names::squareBrackets(),
loc.copyWithZeroLength(), MK::Int(loc, i));
if (auto *mlhs = parser::cast_node<parser::Mlhs>(c.get())) {
stats.emplace_back(desugarMlhs(dctx, mlhs->loc, mlhs, std::move(val)));
} else {
ExpressionPtr lh = node2TreeImpl(dctx, std::move(c));
if (auto restArg = cast_tree<RestArg>(lh)) {
if (auto e = dctx.ctx.beginError(lh.loc(), core::errors::Desugar::UnsupportedRestArgsDestructure)) {
e.setHeader("Unsupported rest args in destructure");
}
lh = move(restArg->expr);
}
auto lhloc = lh.loc();
stats.emplace_back(MK::Assign(lhloc, std::move(lh), std::move(val)));
}
i++;
}
}
auto expanded = MK::Send3(loc, MK::Magic(loc), core::Names::expandSplat(), loc.copyWithZeroLength(),
MK::Local(loc, tempRhs), MK::Int(loc, before), MK::Int(loc, after));
stats.insert(stats.begin(), MK::Assign(loc, tempExpanded, std::move(expanded)));
stats.insert(stats.begin(), MK::Assign(loc, tempRhs, std::move(rhs)));
// Regardless of how we destructure an assignment, Ruby evaluates the expression to the entire right hand side,
// not any individual component of the destructured assignment.
return MK::InsSeq(loc, std::move(stats), MK::Local(loc, tempRhs));
}
// Map all MatchVars used in `pattern` to local variables initialized from magic calls
void desugarPatternMatchingVars(InsSeq::STATS_store &vars, DesugarContext dctx, unique_ptr<parser::Node> &node) {
if (auto var = parser::cast_node<parser::MatchVar>(node.get())) {
auto loc = var->loc;
auto val = MK::RaiseUnimplemented(loc);
vars.emplace_back(MK::Assign(loc, var->name, std::move(val)));
} else if (auto rest = parser::cast_node<parser::MatchRest>(node.get())) {
desugarPatternMatchingVars(vars, dctx, rest->var);
} else if (auto pair = parser::cast_node<parser::Pair>(node.get())) {
desugarPatternMatchingVars(vars, dctx, pair->value);
} else if (auto as_pattern = parser::cast_node<parser::MatchAs>(node.get())) {
auto loc = as_pattern->as->loc;
auto name = parser::cast_node<parser::MatchVar>(as_pattern->as.get())->name;
auto val = MK::RaiseUnimplemented(loc);
vars.emplace_back(MK::Assign(loc, name, std::move(val)));
desugarPatternMatchingVars(vars, dctx, as_pattern->value);
} else if (auto array_pattern = parser::cast_node<parser::ArrayPattern>(node.get())) {
for (auto &elt : array_pattern->elts) {
desugarPatternMatchingVars(vars, dctx, elt);
}
} else if (auto array_pattern = parser::cast_node<parser::ArrayPatternWithTail>(node.get())) {
for (auto &elt : array_pattern->elts) {
desugarPatternMatchingVars(vars, dctx, elt);
}
} else if (auto hash_pattern = parser::cast_node<parser::HashPattern>(node.get())) {
for (auto &elt : hash_pattern->pairs) {
desugarPatternMatchingVars(vars, dctx, elt);
}
} else if (auto alt_pattern = parser::cast_node<parser::MatchAlt>(node.get())) {
desugarPatternMatchingVars(vars, dctx, alt_pattern->left);
desugarPatternMatchingVars(vars, dctx, alt_pattern->right);
}
}
// Desugar `in` and `=>` oneline pattern matching
ExpressionPtr desugarOnelinePattern(DesugarContext dctx, core::LocOffsets loc, unique_ptr<parser::Node> &match) {
auto matchExpr = MK::RaiseUnimplemented(loc);
auto bodyExpr = MK::RaiseUnimplemented(loc);
auto elseExpr = MK::EmptyTree();
InsSeq::STATS_store vars;
desugarPatternMatchingVars(vars, dctx, match);
if (!vars.empty()) {
bodyExpr = MK::InsSeq(match->loc, std::move(vars), std::move(bodyExpr));
}
return MK::If(loc, std::move(matchExpr), std::move(bodyExpr), std::move(elseExpr));
}
bool locReported = false;
ClassDef::RHS_store scopeNodeToBody(DesugarContext dctx, unique_ptr<parser::Node> node) {
ClassDef::RHS_store body;
// Reset uniqueCounter within this scope (to keep numbers small)
uint32_t uniqueCounter = 1;
DesugarContext dctx1(dctx.ctx, uniqueCounter, dctx.enclosingBlockArg, dctx.enclosingMethodLoc,
dctx.enclosingMethodName);
if (auto *begin = parser::cast_node<parser::Begin>(node.get())) {
body.reserve(begin->stmts.size());
for (auto &stat : begin->stmts) {
body.emplace_back(node2TreeImpl(dctx1, std::move(stat)));
};
} else {
body.emplace_back(node2TreeImpl(dctx1, std::move(node)));
}
return body;
}
Send *asTLet(ExpressionPtr &arg) {
auto *send = cast_tree<Send>(arg);
if (send == nullptr || send->fun != core::Names::let() || send->numPosArgs() < 2) {
return nullptr;
}
auto *recv = cast_tree<UnresolvedConstantLit>(send->recv);
if (recv == nullptr || recv->cnst != core::Names::Constants::T() || !isa_tree<EmptyTree>(recv->scope)) {
return nullptr;
}
return send;
}
struct OpAsgnScaffolding {
core::NameRef temporaryName;
InsSeq::STATS_store statementBody;
uint16_t numPosArgs;
Send::ARGS_store readArgs;
Send::ARGS_store assgnArgs;
};
// Desugaring passes for op-assignments (like += or &&=) will first desugar the LHS, which often results in a send if
// there's a dot anywhere on the LHS. Consider an expression like `x.y += 1`. We'll want to desugar this to
//
// { $tmp = x.y; x.y = $tmp + 1 }
//
// which now involves two (slightly different) sends: the .y() in the first statement, and the .y=() in the second
// statement. The first one will have as many arguments as the original, while the second will have one more than the
// original (to allow for the passed value). This function creates both argument lists as well as the instruction block
// and the temporary variable: how these will be used will differ slightly depending on whether we're desugaring &&=,
// ||=, or some other op-assign, but the logic contained here will stay in common.
OpAsgnScaffolding copyArgsForOpAsgn(DesugarContext dctx, Send *s) {
// this is for storing the temporary assignments followed by the final update. In the case that we have other
// arguments to the send (e.g. in the case of x.y[z] += 1) we'll want to store the other parameters (z) in a
// temporary as well, producing a sequence like
//
// { $arg = z; $tmp = x.y[$arg]; x.y[$arg] = $tmp + 1 }
//
// This means we'll always need statements for as many arguments as the send has, plus two more: one for the
// temporary assignment and the last for the actual update we're desugaring.
ENFORCE(!s->hasKwArgs() && !s->hasBlock());
const auto numPosArgs = s->numPosArgs();
InsSeq::STATS_store stats;
stats.reserve(numPosArgs + 2);
core::NameRef tempRecv = dctx.freshNameUnique(s->fun);
stats.emplace_back(MK::Assign(s->loc, tempRecv, std::move(s->recv)));
Send::ARGS_store readArgs;
Send::ARGS_store assgnArgs;
// these are the arguments for the first send, e.g. x.y(). The number of arguments should be identical to whatever
// we saw on the LHS.
readArgs.reserve(numPosArgs);
// these are the arguments for the second send, e.g. x.y=(val). That's why we need the space for the extra argument
// here: to accomodate the call to field= instead of just field.
assgnArgs.reserve(numPosArgs + 1);
for (auto &arg : s->posArgs()) {
auto argLoc = arg.loc();
core::NameRef name = dctx.freshNameUnique(s->fun);
stats.emplace_back(MK::Assign(argLoc, name, std::move(arg)));
readArgs.emplace_back(MK::Local(argLoc, name));
assgnArgs.emplace_back(MK::Local(argLoc, name));
}
return {tempRecv, std::move(stats), numPosArgs, std::move(readArgs), std::move(assgnArgs)};
}
// while true
// body
// if cond
// break
// end
// end
ExpressionPtr doUntil(DesugarContext dctx, core::LocOffsets loc, ExpressionPtr cond, ExpressionPtr body) {
auto breaker = MK::If(loc, std::move(cond), MK::Break(loc, MK::EmptyTree()), MK::EmptyTree());
auto breakWithBody = MK::InsSeq1(loc, std::move(body), std::move(breaker));
return MK::While(loc, MK::True(loc), std::move(breakWithBody));
}
class DuplicateHashKeyCheck {
DesugarContext dctx;
const core::GlobalState &gs;
UnorderedMap<core::NameRef, core::LocOffsets> hashKeySymbols;
UnorderedMap<core::NameRef, core::LocOffsets> hashKeyStrings;
public:
DuplicateHashKeyCheck(DesugarContext dctx) : dctx{dctx}, gs{dctx.ctx.state}, hashKeySymbols(), hashKeyStrings() {}
void check(const ExpressionPtr &key) {
auto lit = ast::cast_tree<ast::Literal>(key);
if (lit == nullptr) {
return;
}
auto isSymbol = lit->isSymbol();
core::NameRef nameRef;
if (!lit) {
return;
}
if (isSymbol) {
nameRef = lit->asSymbol();
} else if (lit->isString()) {
nameRef = lit->asString();
} else {
return;
}
if (isSymbol && !hashKeySymbols.contains(nameRef)) {
hashKeySymbols[nameRef] = key.loc();
} else if (!isSymbol && !hashKeyStrings.contains(nameRef)) {
hashKeyStrings[nameRef] = key.loc();
} else {
if (auto e = dctx.ctx.beginError(key.loc(), core::errors::Desugar::DuplicatedHashKeys)) {
core::LocOffsets originalLoc;
if (isSymbol) {
originalLoc = hashKeySymbols[nameRef];
} else {
originalLoc = hashKeyStrings[nameRef];
}
e.setHeader("Hash key `{}` is duplicated", nameRef.toString(gs));
e.addErrorLine(dctx.ctx.locAt(originalLoc), "First occurrence of `{}` hash key", nameRef.toString(gs));
}
}
}
void reset() {
hashKeySymbols.clear();
hashKeyStrings.clear();
}
// This is only used with Send::ARGS_store and Array::ELEMS_store
template <typename T> static void checkSendArgs(DesugarContext dctx, int numPosArgs, const T &args) {
DuplicateHashKeyCheck duplicateKeyCheck{dctx};
// increment by two so that a keyword args splat gets skipped.
for (int i = numPosArgs; i < args.size(); i += 2) {
duplicateKeyCheck.check(args[i]);
}
}
};
ExpressionPtr node2TreeImpl(DesugarContext dctx, unique_ptr<parser::Node> what) {
try {
if (what.get() == nullptr) {
return MK::EmptyTree();
}
auto loc = what->loc;
auto locZeroLen = what->loc.copyWithZeroLength();
ENFORCE(loc.exists(), "parse-tree node has no location: {}", what->toString(dctx.ctx));
ExpressionPtr result;
typecase(
what.get(),
// The top N clauses here are ordered according to observed
// frequency in pay-server. Do not reorder the top of this list, or
// add entries here, without consulting the "node.*" counters from a
// run over a representative code base.
[&](parser::Const *const_) {
auto scope = node2TreeImpl(dctx, std::move(const_->scope));
ExpressionPtr res = MK::UnresolvedConstant(loc, std::move(scope), const_->name);
result = std::move(res);
},
[&](parser::Send *send) {
Send::Flags flags;
auto rec = node2TreeImpl(dctx, std::move(send->receiver));
if (isa_tree<EmptyTree>(rec)) {
// 0-sized Loc, since `self.` doesn't appear in the original file.
rec = MK::Self(loc.copyWithZeroLength());
flags.isPrivateOk = true;
} else if (rec.isSelfReference()) {
// In Ruby 2.7 `self.foo()` is also allowed for private method calls,
// not only `foo()`. This pre-emptively allow the new syntax.
flags.isPrivateOk = true;
}
if (absl::c_any_of(send->args, [](auto &arg) {
return parser::isa_node<parser::Splat>(arg.get()) ||
parser::isa_node<parser::ForwardedArgs>(arg.get());
})) {
// Build up an array that represents the keyword args for the send. When there is a Kwsplat, treat
// all keyword arguments as a single argument.
unique_ptr<parser::Node> kwArray;
// If there's a &blk node in the last position, pop that off (we'll put it back later, but
// subsequent logic for dealing with the kwargs hash is simpler this way).
unique_ptr<parser::Node> savedBlockPass = nullptr;
if (!send->args.empty() && parser::isa_node<parser::BlockPass>(send->args.back().get())) {
savedBlockPass = std::move(send->args.back());
send->args.pop_back();
}
// Deconstruct the kwargs hash if it's present.
if (!send->args.empty()) {
if (auto *hash = parser::cast_node<parser::Hash>(send->args.back().get())) {
if (hash->kwargs) {
// hold a reference to the node, and remove it from the back of the send list
auto node = std::move(send->args.back());
send->args.pop_back();
parser::NodeVec elts;
// skip inlining the kwargs if there are any kwsplat nodes present
if (absl::c_any_of(hash->pairs, [](auto &node) {
// the parser guarantees that if we see a kwargs hash it only contains pair or
// kwsplat nodes
ENFORCE(parser::isa_node<parser::Kwsplat>(node.get()) ||
parser::isa_node<parser::Pair>(node.get()));
return parser::isa_node<parser::Kwsplat>(node.get());
})) {
elts.emplace_back(std::move(node));
} else {
// inline the hash into the send args
for (auto &entry : hash->pairs) {
typecase(
entry.get(),
[&](parser::Pair *pair) {
elts.emplace_back(std::move(pair->key));
elts.emplace_back(std::move(pair->value));
},
[&](parser::Node *node) { Exception::raise("Unhandled case"); });
}
}
kwArray = make_unique<parser::Array>(loc, std::move(elts));
}
}
}
// Put the &blk arg back, if present.
if (savedBlockPass) {
send->args.emplace_back(std::move(savedBlockPass));
}
// If the kwargs hash is not present, make a `nil` to put in the place of that argument. This
// will be used in the implementation of the intrinsic to tell the difference between keyword
// args, keyword args with kw splats, and no keyword args at all.
if (kwArray == nullptr) {
kwArray = make_unique<parser::Nil>(loc);
}
// If we have a splat anywhere in the argument list, desugar
// the argument list as a single Array node, and then
// synthesize a call to
// Magic.callWithSplat(receiver, method, argArray, [&blk])
// The callWithSplat implementation (in C++) will unpack a
// tuple type and call into the normal call merchanism.
unique_ptr<parser::Node> block;
auto argnodes = std::move(send->args);
bool anonymousBlockPass = false;
core::LocOffsets bpLoc;
auto it = absl::c_find_if(argnodes,
[](auto &arg) { return parser::isa_node<parser::BlockPass>(arg.get()); });
if (it != argnodes.end()) {
auto *bp = parser::cast_node<parser::BlockPass>(it->get());
if (bp->block == nullptr) {
anonymousBlockPass = true;
bpLoc = bp->loc;
} else {
block = std::move(bp->block);
}
argnodes.erase(it);
}
auto hasFwdArgs = false;
auto fwdIt = absl::c_find_if(
argnodes, [](auto &arg) { return parser::isa_node<parser::ForwardedArgs>(arg.get()); });
if (fwdIt != argnodes.end()) {
block = make_unique<parser::LVar>(loc, core::Names::fwdBlock());
hasFwdArgs = true;
argnodes.erase(fwdIt);
}
auto array = make_unique<parser::Array>(locZeroLen, std::move(argnodes));
auto args = node2TreeImpl(dctx, std::move(array));
if (hasFwdArgs) {
auto fwdArgs = MK::Local(loc, core::Names::fwdArgs());
auto argsSplat = MK::Send0(loc, std::move(fwdArgs), core::Names::toA(), locZeroLen);
auto argsConcat =
MK::Send1(loc, std::move(args), core::Names::concat(), locZeroLen, std::move(argsSplat));
auto fwdKwargs = MK::Local(loc, core::Names::fwdKwargs());
auto kwargsSplat =
MK::Send1(loc, MK::Magic(loc), core::Names::toHashDup(), locZeroLen, std::move(fwdKwargs));
Array::ENTRY_store kwargsEntries;
kwargsEntries.emplace_back(std::move(kwargsSplat));
auto kwargsArray = MK::Array(loc, std::move(kwargsEntries));
argsConcat = MK::Send1(loc, std::move(argsConcat), core::Names::concat(), locZeroLen,
std::move(kwargsArray));
args = std::move(argsConcat);
}
auto kwargs = node2TreeImpl(dctx, std::move(kwArray));
auto method = MK::Symbol(locZeroLen, send->method);
if (auto *array = cast_tree<Array>(kwargs)) {
DuplicateHashKeyCheck::checkSendArgs(dctx, 0, array->elems);
}
Send::ARGS_store sendargs;
sendargs.emplace_back(std::move(rec));
sendargs.emplace_back(std::move(method));
sendargs.emplace_back(std::move(args));
sendargs.emplace_back(std::move(kwargs));
ExpressionPtr res;
if (block == nullptr && !anonymousBlockPass) {
res = MK::Send(loc, MK::Magic(loc), core::Names::callWithSplat(), send->methodLoc, 4,
std::move(sendargs), flags);
} else {
ExpressionPtr convertedBlock;
if (anonymousBlockPass) {
ENFORCE(block == nullptr, "encountered a block while processing an anonymous block pass");
convertedBlock = MK::Local(bpLoc, core::Names::ampersand());
} else {
convertedBlock = node2TreeImpl(dctx, std::move(block));
}
Literal *lit;
if ((lit = cast_tree<Literal>(convertedBlock)) && lit->isSymbol()) {
res = MK::Send(loc, MK::Magic(loc), core::Names::callWithSplat(), locZeroLen, 4,
std::move(sendargs), flags);
ast::cast_tree_nonnull<ast::Send>(res).setBlock(
symbol2Proc(dctx, std::move(convertedBlock)));
} else {
sendargs.emplace_back(std::move(convertedBlock));
res = MK::Send(loc, MK::Magic(loc), core::Names::callWithSplatAndBlock(), locZeroLen, 5,
std::move(sendargs), flags);
}
}
result = std::move(res);
} else {
int numPosArgs = send->args.size();
if (numPosArgs > 0) {
// Deconstruct the kwargs hash in the last argument if it's present.
if (auto *hash = parser::cast_node<parser::Hash>(send->args.back().get())) {
if (hash->kwargs) {
numPosArgs--;
// skip inlining the kwargs if there are any non-key/value pairs present
if (!absl::c_any_of(hash->pairs, [](auto &node) {
// the parser guarantees that if we see a kwargs hash it only contains pair or
// kwsplat nodes
ENFORCE(parser::isa_node<parser::Kwsplat>(node.get()) ||
parser::isa_node<parser::Pair>(node.get()));
return parser::isa_node<parser::Kwsplat>(node.get());
})) {
// hold a reference to the node, and remove it from the back fo the send list
auto node = std::move(send->args.back());
send->args.pop_back();
// inline the hash into the send args
for (auto &entry : hash->pairs) {
typecase(
entry.get(),
[&](parser::Pair *pair) {
send->args.emplace_back(std::move(pair->key));
send->args.emplace_back(std::move(pair->value));
},
[&](parser::Node *node) { Exception::raise("Unhandled case"); });
}
}
}
}
}
Send::ARGS_store args;
unique_ptr<parser::Node> block;
args.reserve(send->args.size());
bool anonymousBlockPass = false;
core::LocOffsets bpLoc;
for (auto &stat : send->args) {
if (auto bp = parser::cast_node<parser::BlockPass>(stat.get())) {
ENFORCE(block == nullptr, "passing a block where there is no block");
if (bp->block == nullptr) {
anonymousBlockPass = true;
bpLoc = bp->loc;
} else {
block = std::move(bp->block);
}
// we don't count the block arg as part of the positional arguments anymore.
numPosArgs = max(0, numPosArgs - 1);
} else {
args.emplace_back(node2TreeImpl(dctx, std::move(stat)));
}
};
DuplicateHashKeyCheck::checkSendArgs(dctx, numPosArgs, args);
ExpressionPtr res;
if (block == nullptr && !anonymousBlockPass) {
res = MK::Send(loc, std::move(rec), send->method, send->methodLoc, numPosArgs, std::move(args),
flags);
} else {
auto method = MK::Literal(
loc, core::make_type<core::NamedLiteralType>(core::Symbols::Symbol(), send->method));
ExpressionPtr convertedBlock;
if (anonymousBlockPass) {
ENFORCE(block == nullptr, "encountered a block while processing an anonymous block pass");
convertedBlock = MK::Local(bpLoc, core::Names::ampersand());
} else {
convertedBlock = node2TreeImpl(dctx, std::move(block));
}
Literal *lit;
if ((lit = cast_tree<Literal>(convertedBlock)) && lit->isSymbol()) {
res = MK::Send(loc, std::move(rec), send->method, send->methodLoc, numPosArgs,
std::move(args), flags);
ast::cast_tree_nonnull<ast::Send>(res).setBlock(
symbol2Proc(dctx, std::move(convertedBlock)));
} else {
Send::ARGS_store sendargs;
sendargs.emplace_back(std::move(rec));
sendargs.emplace_back(std::move(method));
sendargs.emplace_back(std::move(convertedBlock));
numPosArgs += 3;
for (auto &arg : args) {
sendargs.emplace_back(std::move(arg));
}
res = MK::Send(loc, MK::Magic(loc), core::Names::callWithBlock(), locZeroLen, numPosArgs,
std::move(sendargs), flags);
}
}
if (send->method == core::Names::blockGiven_p() && dctx.enclosingBlockArg.exists()) {
auto if_ = MK::If(loc, MK::Local(loc, dctx.enclosingBlockArg), std::move(res), MK::False(loc));
result = std::move(if_);
} else {
result = std::move(res);
}
}
},
[&](parser::String *string) {
ExpressionPtr res = MK::String(loc, string->val);
result = std::move(res);
},
[&](parser::Symbol *symbol) {
ExpressionPtr res = MK::Symbol(loc, symbol->val);
result = std::move(res);
},
[&](parser::LVar *var) {
ExpressionPtr res = MK::Local(loc, var->name);
result = std::move(res);
},
[&](parser::Hash *hash) {
InsSeq::STATS_store updateStmts;
updateStmts.reserve(hash->pairs.size());
auto acc = dctx.freshNameUnique(core::Names::hashTemp());
DuplicateHashKeyCheck hashKeyDupes(dctx);
Send::ARGS_store mergeValues;
mergeValues.reserve(hash->pairs.size() * 2 + 1);
mergeValues.emplace_back(MK::Local(loc, acc));
bool havePairsToMerge = false;
// build a hash literal assuming that the argument follows the same format as `mergeValues`:
// arg 0: the hash to merge into
// arg 1: key
// arg 2: value
// ...
// arg n: key
// arg n+1: value
auto buildHashLiteral = [loc](Send::ARGS_store &mergeValues) {
Hash::ENTRY_store keys;
Hash::ENTRY_store values;
keys.reserve(mergeValues.size() / 2);
values.reserve(mergeValues.size() / 2);
// skip the first positional argument for the accumulator that would have been mutated
for (auto it = mergeValues.begin() + 1; it != mergeValues.end();) {
keys.emplace_back(std::move(*it++));
values.emplace_back(std::move(*it++));
}
return MK::Hash(loc, std::move(keys), std::move(values));
};
// Desguar
// {**x, a: 'a', **y, remaining}
// into
// acc = <Magic>.<to-hash-dup>(x)
// acc = <Magic>.<merge-hash-values>(acc, :a, 'a')
// acc = <Magic>.<merge-hash>(acc, <Magic>.<to-hash-nodup>(y))
// acc = <Magic>.<merge-hash>(acc, remaining)
// acc
for (auto &pairAsExpression : hash->pairs) {
auto *pair = parser::cast_node<parser::Pair>(pairAsExpression.get());
if (pair != nullptr) {
auto key = node2TreeImpl(dctx, std::move(pair->key));
hashKeyDupes.check(key);
mergeValues.emplace_back(std::move(key));
auto value = node2TreeImpl(dctx, std::move(pair->value));
mergeValues.emplace_back(std::move(value));
havePairsToMerge = true;
continue;
}
auto *splat = parser::cast_node<parser::Kwsplat>(pairAsExpression.get());
ENFORCE(splat != nullptr, "kwsplat cast failed");