ParseNode.h
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef frontend_ParseNode_h
#define frontend_ParseNode_h
#include "mozilla/Attributes.h"
#include "builtin/ModuleObject.h"
#include "frontend/TokenStream.h"
namespace js {
namespace frontend {
template <typename ParseHandler>
struct ParseContext;
class FullParseHandler;
class FunctionBox;
class ModuleBox;
class ObjectBox;
// A packed ScopeCoordinate for use in the frontend during bytecode
// compilation.
//
// Definitions start out !isFree() && isHopsUnknown().
// Uses start out isFree().
//
// The BCE computes the correct number of hops based on the static scope
// chain. This is ncessary because due to hoisting, the Parser does not know
// the final static scope chain.
//
// The BCE also computes the correct slot number depending on whether the
// binding is aliased. If it is aliased, the slot number is the slot on the
// dynamic scope object. Otherwise, the slot number is the frame slot.
class PackedScopeCoordinate
{
uint32_t hops_ : SCOPECOORD_HOPS_BITS;
uint32_t slot_ : SCOPECOORD_SLOT_BITS;
void checkInvariants() {
static_assert(sizeof(PackedScopeCoordinate) == sizeof(uint32_t),
"Not necessary for correctness, but good for ParseNode memory use");
}
public:
// Steal one value to represent the sentinel value signaling that the
// binding is free, and one value to represent the sentinel value
// signaling that the number of hop count need to be computed by the
// BytecodeEmitter.
static const uint32_t UNKNOWN_HOPS = SCOPECOORD_HOPS_LIMIT - 1;
static const uint32_t UNKNOWN_SLOT = SCOPECOORD_SLOT_LIMIT - 1;
bool isHopsUnknown() const { return hops_ == UNKNOWN_HOPS; }
bool isFree() const { return slot_ == UNKNOWN_SLOT; }
uint32_t hops() const { MOZ_ASSERT(!isFree()); return hops_; }
uint32_t slot() const { MOZ_ASSERT(!isFree()); return slot_; }
bool setSlot(TokenStream& ts, uint32_t newSlot) {
if (newSlot >= UNKNOWN_SLOT)
return ts.reportError(JSMSG_TOO_MANY_LOCALS);
slot_ = newSlot;
return true;
}
bool setHops(TokenStream& ts, uint32_t newHops) {
if (newHops >= UNKNOWN_HOPS)
return ts.reportError(JSMSG_TOO_DEEP, js_function_str);
hops_ = newHops;
return true;
}
bool set(TokenStream& ts, uint32_t newHops, uint32_t newSlot) {
return setHops(ts, newHops) && setSlot(ts, newSlot);
}
void makeFree() {
hops_ = UNKNOWN_HOPS;
slot_ = UNKNOWN_SLOT;
MOZ_ASSERT(isFree());
}
};
#define FOR_EACH_PARSE_NODE_KIND(F) \
F(NOP) \
F(SEMI) \
F(COMMA) \
F(CONDITIONAL) \
F(COLON) \
F(SHORTHAND) \
F(POS) \
F(NEG) \
F(PREINCREMENT) \
F(POSTINCREMENT) \
F(PREDECREMENT) \
F(POSTDECREMENT) \
F(DOT) \
F(ELEM) \
F(ARRAY) \
F(ELISION) \
F(STATEMENTLIST) \
F(LABEL) \
F(OBJECT) \
F(CALL) \
F(NAME) \
F(OBJECT_PROPERTY_NAME) \
F(COMPUTED_NAME) \
F(NUMBER) \
F(STRING) \
F(TEMPLATE_STRING_LIST) \
F(TEMPLATE_STRING) \
F(TAGGED_TEMPLATE) \
F(CALLSITEOBJ) \
F(REGEXP) \
F(TRUE) \
F(FALSE) \
F(NULL) \
F(THIS) \
F(FUNCTION) \
F(MODULE) \
F(IF) \
F(SWITCH) \
F(CASE) \
F(WHILE) \
F(DOWHILE) \
F(FOR) \
F(COMPREHENSIONFOR) \
F(BREAK) \
F(CONTINUE) \
F(VAR) \
F(CONST) \
F(WITH) \
F(RETURN) \
F(NEW) \
/* Delete operations. These must be sequential. */ \
F(DELETENAME) \
F(DELETEPROP) \
F(DELETEELEM) \
F(DELETEEXPR) \
F(TRY) \
F(CATCH) \
F(CATCHLIST) \
F(THROW) \
F(DEBUGGER) \
F(GENERATOR) \
F(YIELD) \
F(YIELD_STAR) \
F(GENEXP) \
F(ARRAYCOMP) \
F(ARRAYPUSH) \
F(LEXICALSCOPE) \
F(LET) \
F(LETBLOCK) \
F(IMPORT) \
F(IMPORT_SPEC_LIST) \
F(IMPORT_SPEC) \
F(EXPORT) \
F(EXPORT_FROM) \
F(EXPORT_DEFAULT) \
F(EXPORT_SPEC_LIST) \
F(EXPORT_SPEC) \
F(EXPORT_BATCH_SPEC) \
F(FORIN) \
F(FOROF) \
F(FORHEAD) \
F(ANNEXB_FUNCTION) \
F(ARGSBODY) \
F(SPREAD) \
F(MUTATEPROTO) \
F(CLASS) \
F(CLASSMETHOD) \
F(CLASSMETHODLIST) \
F(CLASSNAMES) \
F(NEWTARGET) \
F(POSHOLDER) \
F(SUPERBASE) \
F(SUPERCALL) \
F(SETTHIS) \
\
/* Unary operators. */ \
F(TYPEOFNAME) \
F(TYPEOFEXPR) \
F(VOID) \
F(NOT) \
F(BITNOT) \
\
/* \
* Binary operators. \
* These must be in the same order as TOK_OR and friends in TokenStream.h. \
*/ \
F(OR) \
F(AND) \
F(BITOR) \
F(BITXOR) \
F(BITAND) \
F(STRICTEQ) \
F(EQ) \
F(STRICTNE) \
F(NE) \
F(LT) \
F(LE) \
F(GT) \
F(GE) \
F(INSTANCEOF) \
F(IN) \
F(LSH) \
F(RSH) \
F(URSH) \
F(ADD) \
F(SUB) \
F(STAR) \
F(DIV) \
F(MOD) \
F(POW) \
\
/* Assignment operators (= += -= etc.). */ \
/* ParseNode::isAssignment assumes all these are consecutive. */ \
F(ASSIGN) \
F(ADDASSIGN) \
F(SUBASSIGN) \
F(BITORASSIGN) \
F(BITXORASSIGN) \
F(BITANDASSIGN) \
F(LSHASSIGN) \
F(RSHASSIGN) \
F(URSHASSIGN) \
F(MULASSIGN) \
F(DIVASSIGN) \
F(MODASSIGN) \
F(POWASSIGN)
/*
* Parsing builds a tree of nodes that directs code generation. This tree is
* not a concrete syntax tree in all respects (for example, || and && are left
* associative, but (A && B && C) translates into the right-associated tree
* <A && <B && C>> so that code generation can emit a left-associative branch
* around <B && C> when A is false). Nodes are labeled by kind, with a
* secondary JSOp label when needed.
*
* The long comment after this enum block describes the kinds in detail.
*/
enum ParseNodeKind
{
#define EMIT_ENUM(name) PNK_##name,
FOR_EACH_PARSE_NODE_KIND(EMIT_ENUM)
#undef EMIT_ENUM
PNK_LIMIT, /* domain size */
PNK_BINOP_FIRST = PNK_OR,
PNK_BINOP_LAST = PNK_POW,
PNK_ASSIGNMENT_START = PNK_ASSIGN,
PNK_ASSIGNMENT_LAST = PNK_POWASSIGN
};
inline bool
IsDeleteKind(ParseNodeKind kind)
{
return PNK_DELETENAME <= kind && kind <= PNK_DELETEEXPR;
}
/*
* Label Variant Members
* ----- ------- -------
* <Definitions>
* PNK_FUNCTION name pn_funbox: ptr to js::FunctionBox holding function
* object containing arg and var properties. We
* create the function object at parse (not emit)
* time to specialize arg and var bytecodes early.
* pn_body: PNK_ARGSBODY, ordinarily;
* PNK_LEXICALSCOPE for implicit function in genexpr
* pn_scopecoord: hops and var index for function
* pn_dflags: PND_* definition/use flags (see below)
* pn_blockid: block id number
* PNK_ANNEXB_FUNCTION binary pn_left: PNK_FUNCTION
* pn_right: assignment for annex B semantics for
* block-scoped function
* PNK_ARGSBODY list list of formal parameters with
* PNK_NAME node with non-empty name for
* SingleNameBinding without Initializer
* PNK_ASSIGN node for SingleNameBinding with
* Initializer
* PNK_NAME node with empty name for destructuring
* pn_expr: PNK_ARRAY, PNK_OBJECT, or PNK_ASSIGN
* PNK_ARRAY or PNK_OBJECT for BindingPattern
* without Initializer
* PNK_ASSIGN for BindingPattern with
* Initializer
* followed by:
* PNK_STATEMENTLIST node for function body
* statements,
* PNK_RETURN for expression closure
* pn_count: 1 + number of formal parameters
* pn_tree: PNK_ARGSBODY or PNK_STATEMENTLIST node
* PNK_SPREAD unary pn_kid: expression being spread
*
* <Statements>
* PNK_STATEMENTLIST list pn_head: list of pn_count statements
* PNK_IF ternary pn_kid1: cond, pn_kid2: then, pn_kid3: else or null.
* In body of a comprehension or desugared generator
* expression, pn_kid2 is PNK_YIELD, PNK_ARRAYPUSH,
* or (if the push was optimized away) empty
* PNK_STATEMENTLIST.
* PNK_SWITCH binary pn_left: discriminant
* pn_right: list of PNK_CASE nodes, with at most one
* default node, or if there are let bindings
* in the top level of the switch body's cases, a
* PNK_LEXICALSCOPE node that contains the list of
* PNK_CASE nodes.
* PNK_CASE binary pn_left: case-expression if CaseClause, or
* null if DefaultClause
* pn_right: PNK_STATEMENTLIST node for this case's
* statements
* pn_u.binary.offset: scratch space for the emitter
* PNK_WHILE binary pn_left: cond, pn_right: body
* PNK_DOWHILE binary pn_left: body, pn_right: cond
* PNK_FOR binary pn_left: either PNK_FORIN (for-in statement),
* PNK_FOROF (for-of) or PNK_FORHEAD (for(;;))
* pn_right: body
* PNK_COMPREHENSIONFOR pn_left: either PNK_FORIN or PNK_FOROF
* binary pn_right: body
* PNK_FORIN ternary pn_kid1: PNK_VAR to left of 'in', or nullptr
* pn_kid2: PNK_NAME or destructuring expr
* to left of 'in'; if pn_kid1, then this
* is a clone of pn_kid1->pn_head
* pn_kid3: object expr to right of 'in'
* PNK_FOROF ternary pn_kid1: PNK_VAR to left of 'of', or nullptr
* pn_kid2: PNK_NAME or destructuring expr
* to left of 'of'; if pn_kid1, then this
* is a clone of pn_kid1->pn_head
* pn_kid3: expr to right of 'of'
* PNK_FORHEAD ternary pn_kid1: init expr before first ';' or nullptr
* pn_kid2: cond expr before second ';' or nullptr
* pn_kid3: update expr after second ';' or nullptr
* PNK_THROW unary pn_op: JSOP_THROW, pn_kid: exception
* PNK_TRY ternary pn_kid1: try block
* pn_kid2: null or PNK_CATCHLIST list
* pn_kid3: null or finally block
* PNK_CATCHLIST list pn_head: list of PNK_LEXICALSCOPE nodes, one per
* catch-block, each with pn_expr pointing
* to a PNK_CATCH node
* PNK_CATCH ternary pn_kid1: PNK_NAME, PNK_ARRAY, or PNK_OBJECT catch var node
* (PNK_ARRAY or PNK_OBJECT if destructuring)
* pn_kid2: null or the catch guard expression
* pn_kid3: catch block statements
* PNK_BREAK name pn_atom: label or null
* PNK_CONTINUE name pn_atom: label or null
* PNK_WITH binary-obj pn_left: head expr; pn_right: body; pn_binary_obj: StaticWithScope
* PNK_VAR, list pn_head: list of PNK_NAME or PNK_ASSIGN nodes
* PNK_CONST each name node has either
* pn_used: false
* pn_atom: variable name
* pn_expr: initializer or null
* or
* pn_used: true
* pn_atom: variable name
* pn_lexdef: def node
* each assignment node has
* pn_left: PNK_NAME with pn_used true and
* pn_lexdef (NOT pn_expr) set
* pn_right: initializer
* PNK_RETURN unary pn_kid: return expr or null
* PNK_SEMI unary pn_kid: expr or null statement
* pn_prologue: true if Directive Prologue member
* in original source, not introduced via
* constant folding or other tree rewriting
* PNK_LABEL name pn_atom: label, pn_expr: labeled statement
* PNK_IMPORT binary pn_left: PNK_IMPORT_SPEC_LIST import specifiers
* pn_right: PNK_STRING module specifier
* PNK_EXPORT unary pn_kid: declaration expression
* PNK_EXPORT_FROM binary pn_left: PNK_EXPORT_SPEC_LIST export specifiers
* pn_right: PNK_STRING module specifier
* PNK_EXPORT_DEFAULT unary pn_kid: export default declaration or expression
*
* <Expressions>
* All left-associated binary trees of the same type are optimized into lists
* to avoid recursion when processing expression chains.
* PNK_COMMA list pn_head: list of pn_count comma-separated exprs
* PNK_ASSIGN binary pn_left: lvalue, pn_right: rvalue
* PNK_ADDASSIGN, binary pn_left: lvalue, pn_right: rvalue
* PNK_SUBASSIGN, pn_op: JSOP_ADD for +=, etc.
* PNK_BITORASSIGN,
* PNK_BITXORASSIGN,
* PNK_BITANDASSIGN,
* PNK_LSHASSIGN,
* PNK_RSHASSIGN,
* PNK_URSHASSIGN,
* PNK_MULASSIGN,
* PNK_DIVASSIGN,
* PNK_MODASSIGN,
* PNK_POWASSIGN
* PNK_CONDITIONAL ternary (cond ? trueExpr : falseExpr)
* pn_kid1: cond, pn_kid2: then, pn_kid3: else
* PNK_OR, list pn_head; list of pn_count subexpressions
* PNK_AND, All of these operators are left-associative except (**).
* PNK_BITOR,
* PNK_BITXOR,
* PNK_BITAND,
* PNK_EQ,
* PNK_NE,
* PNK_STRICTEQ,
* PNK_STRICTNE,
* PNK_LT,
* PNK_LE,
* PNK_GT,
* PNK_GE,
* PNK_LSH,
* PNK_RSH,
* PNK_URSH,
* PNK_ADD,
* PNK_SUB,
* PNK_STAR,
* PNK_DIV,
* PNK_MOD,
* PNK_POW (**) is right-associative, but forms a list
* nonetheless. Special hacks everywhere.
*
* PNK_POS, unary pn_kid: UNARY expr
* PNK_NEG
* PNK_VOID, unary pn_kid: UNARY expr
* PNK_NOT,
* PNK_BITNOT
* PNK_TYPEOFNAME, unary pn_kid: UNARY expr
* PNK_TYPEOFEXPR
* PNK_PREINCREMENT, unary pn_kid: MEMBER expr
* PNK_POSTINCREMENT,
* PNK_PREDECREMENT,
* PNK_POSTDECREMENT
* PNK_NEW list pn_head: list of ctor, arg1, arg2, ... argN
* pn_count: 1 + N (where N is number of args)
* ctor is a MEMBER expr
* PNK_DELETENAME unary pn_kid: PNK_NAME expr
* PNK_DELETEPROP unary pn_kid: PNK_DOT expr
* PNK_DELETEELEM unary pn_kid: PNK_ELEM expr
* PNK_DELETESUPERELEM unary pn_kid: PNK_SUPERELEM expr
* PNK_DELETEEXPR unary pn_kid: MEMBER expr that's evaluated, then the
* overall delete evaluates to true; can't be a kind
* for a more-specific PNK_DELETE* unless constant
* folding (or a similar parse tree manipulation) has
* occurred
* PNK_DOT name pn_expr: MEMBER expr to left of .
* pn_atom: name to right of .
* PNK_ELEM binary pn_left: MEMBER expr to left of [
* pn_right: expr between [ and ]
* PNK_CALL list pn_head: list of call, arg1, arg2, ... argN
* pn_count: 1 + N (where N is number of args)
* call is a MEMBER expr naming a callable object
* PNK_GENEXP list Exactly like PNK_CALL, used for the implicit call
* in the desugaring of a generator-expression.
* PNK_ARRAY list pn_head: list of pn_count array element exprs
* [,,] holes are represented by PNK_ELISION nodes
* pn_xflags: PN_ENDCOMMA if extra comma at end
* PNK_OBJECT list pn_head: list of pn_count binary PNK_COLON nodes
* PNK_COLON binary key-value pair in object initializer or
* destructuring lhs
* pn_left: property id, pn_right: value
* PNK_SHORTHAND binary Same fields as PNK_COLON. This is used for object
* literal properties using shorthand ({x}).
* PNK_COMPUTED_NAME unary ES6 ComputedPropertyName.
* pn_kid: the AssignmentExpression inside the square brackets
* PNK_NAME, name pn_atom: name, string, or object atom
* PNK_STRING pn_op: JSOP_GETNAME, JSOP_STRING, or JSOP_OBJECT
* If JSOP_GETNAME, pn_op may be JSOP_*ARG or JSOP_*VAR
* with pn_scoppecord telling (hops, slot) and pn_dflags
* telling const-ness and static analysis results
* PNK_TEMPLATE_STRING_LIST pn_head: list of alternating expr and template strings
* list
* PNK_TEMPLATE_STRING pn_atom: template string atom
nullary pn_op: JSOP_NOP
* PNK_TAGGED_TEMPLATE pn_head: list of call, call site object, arg1, arg2, ... argN
* list pn_count: 2 + N (N is the number of substitutions)
* PNK_CALLSITEOBJ list pn_head: a PNK_ARRAY node followed by
* list of pn_count - 1 PNK_TEMPLATE_STRING nodes
* PNK_REGEXP nullary pn_objbox: RegExp model object
* PNK_NAME name If pn_used, PNK_NAME uses the lexdef member instead
* of the expr member it overlays
* PNK_NUMBER dval pn_dval: double value of numeric literal
* PNK_TRUE, nullary pn_op: JSOp bytecode
* PNK_FALSE,
* PNK_NULL
*
* PNK_THIS, unary pn_kid: '.this' Name if function `this`, else nullptr
* PNK_SUPERBASE unary pn_kid: '.this' Name
*
* PNK_SETTHIS binary pn_left: '.this' Name, pn_right: SuperCall
*
* PNK_LEXICALSCOPE name pn_objbox: block object in ObjectBox holder
* pn_expr: block body
* PNK_GENERATOR nullary
* PNK_YIELD, binary pn_left: expr or null; pn_right: generator object
* PNK_YIELD_STAR
* PNK_ARRAYCOMP list pn_count: 1
* pn_head: list of 1 element, which is block
* enclosing for loop(s) and optionally
* if-guarded PNK_ARRAYPUSH
* PNK_ARRAYPUSH unary pn_op: JSOP_ARRAYCOMP
* pn_kid: array comprehension expression
* PNK_NOP nullary
*/
enum ParseNodeArity
{
PN_NULLARY, /* 0 kids, only pn_atom/pn_dval/etc. */
PN_UNARY, /* one kid, plus a couple of scalars */
PN_BINARY, /* two kids, plus a couple of scalars */
PN_BINARY_OBJ, /* two kids, plus an objbox */
PN_TERNARY, /* three kids */
PN_CODE, /* module or function definition node */
PN_LIST, /* generic singly linked list */
PN_NAME /* name use or definition node */
};
struct Definition;
class LoopControlStatement;
class BreakStatement;
class ContinueStatement;
class ConditionalExpression;
class PropertyAccess;
class ParseNode
{
uint32_t pn_type : 16, /* PNK_* type */
pn_op : 8, /* see JSOp enum and jsopcode.tbl */
pn_arity : 4, /* see ParseNodeArity enum */
pn_parens : 1, /* this expr was enclosed in parens */
pn_used : 1, /* name node is on a use-chain */
pn_defn : 1; /* this node is a Definition */
ParseNode(const ParseNode& other) = delete;
void operator=(const ParseNode& other) = delete;
public:
ParseNode(ParseNodeKind kind, JSOp op, ParseNodeArity arity)
: pn_type(kind), pn_op(op), pn_arity(arity), pn_parens(0), pn_used(0), pn_defn(0),
pn_pos(0, 0), pn_next(nullptr), pn_link(nullptr)
{
MOZ_ASSERT(kind < PNK_LIMIT);
memset(&pn_u, 0, sizeof pn_u);
}
ParseNode(ParseNodeKind kind, JSOp op, ParseNodeArity arity, const TokenPos& pos)
: pn_type(kind), pn_op(op), pn_arity(arity), pn_parens(0), pn_used(0), pn_defn(0),
pn_pos(pos), pn_next(nullptr), pn_link(nullptr)
{
MOZ_ASSERT(kind < PNK_LIMIT);
memset(&pn_u, 0, sizeof pn_u);
}
JSOp getOp() const { return JSOp(pn_op); }
void setOp(JSOp op) { pn_op = op; }
bool isOp(JSOp op) const { return getOp() == op; }
ParseNodeKind getKind() const {
MOZ_ASSERT(pn_type < PNK_LIMIT);
return ParseNodeKind(pn_type);
}
void setKind(ParseNodeKind kind) {
MOZ_ASSERT(kind < PNK_LIMIT);
pn_type = kind;
}
bool isKind(ParseNodeKind kind) const { return getKind() == kind; }
ParseNodeArity getArity() const { return ParseNodeArity(pn_arity); }
bool isArity(ParseNodeArity a) const { return getArity() == a; }
void setArity(ParseNodeArity a) { pn_arity = a; }
bool isAssignment() const {
ParseNodeKind kind = getKind();
return PNK_ASSIGNMENT_START <= kind && kind <= PNK_ASSIGNMENT_LAST;
}
bool isBinaryOperation() const {
ParseNodeKind kind = getKind();
return PNK_BINOP_FIRST <= kind && kind <= PNK_BINOP_LAST;
}
/* Boolean attributes. */
bool isInParens() const { return pn_parens; }
bool isLikelyIIFE() const { return isInParens(); }
void setInParens(bool enabled) { pn_parens = enabled; }
bool isUsed() const { return pn_used; }
void setUsed(bool enabled) { pn_used = enabled; }
bool isDefn() const { return pn_defn; }
void setDefn(bool enabled) { pn_defn = enabled; }
static const unsigned NumDefinitionFlagBits = 10;
static const unsigned NumListFlagBits = 10;
static const unsigned NumBlockIdBits = 22;
static_assert(NumDefinitionFlagBits == NumListFlagBits,
"Assumed below to achieve consistent blockid offset");
static_assert(NumDefinitionFlagBits + NumBlockIdBits <= 32,
"This is supposed to fit in a single uint32_t");
TokenPos pn_pos; /* two 16-bit pairs here, for 64 bits */
ParseNode* pn_next; /* intrinsic link in parent PN_LIST */
/*
* Nodes that represent lexical bindings may, in addition to being
* ParseNodes, also be Definition nodes. (Definition is defined far below,
* with a lengthy comment that you should read.) Each binding has one
* canonical Definition; all uses of that definition are reached starting
* from dn_uses, then following subsequent pn_link pointers.
*
* The dn_uses chain elements are unordered. Any apparent ordering in some
* cases, will not be present in all others.
*/
union {
ParseNode* dn_uses;
ParseNode* pn_link;
};
union {
struct { /* list of next-linked nodes */
ParseNode* head; /* first node in list */
ParseNode** tail; /* ptr to ptr to last node in list */
uint32_t count; /* number of nodes in list */
uint32_t xflags:NumListFlagBits, /* see PNX_* below */
blockid:NumBlockIdBits; /* see name variant below */
} list;
struct { /* ternary: if, for(;;), ?: */
ParseNode* kid1; /* condition, discriminant, etc. */
ParseNode* kid2; /* then-part, case list, etc. */
ParseNode* kid3; /* else-part, default case, etc. */
} ternary;
struct { /* two kids if binary */
ParseNode* left;
ParseNode* right;
union {
unsigned iflags; /* JSITER_* flags for PNK_{COMPREHENSION,}FOR node */
ObjectBox* objbox; /* only for PN_BINARY_OBJ */
bool isStatic; /* only for PNK_CLASSMETHOD */
uint32_t offset; /* for the emitter's use on PNK_CASE nodes */
};
} binary;
struct { /* one kid if unary */
ParseNode* kid;
bool prologue; /* directive prologue member (as
pn_prologue) */
} unary;
struct { /* name, labeled statement, etc. */
union {
JSAtom* atom; /* lexical name or label atom */
ObjectBox* objbox; /* block or regexp object */
FunctionBox* funbox; /* function object */
ModuleBox* modulebox; /* module object */
};
union {
ParseNode* expr; /* module or function body, var
initializer, argument default, or
base object of PNK_DOT */
Definition* lexdef; /* lexical definition for this use */
};
PackedScopeCoordinate scopeCoord;
uint32_t dflags:NumDefinitionFlagBits, /* see PND_* below */
blockid:NumBlockIdBits; /* block number, for subset dominance
computation */
} name;
struct {
double value; /* aligned numeric literal value */
DecimalPoint decimalPoint; /* Whether the number has a decimal point */
} number;
class {
friend class LoopControlStatement;
PropertyName* label; /* target of break/continue statement */
} loopControl;
} pn_u;
#define pn_modulebox pn_u.name.modulebox
#define pn_objbox pn_u.name.objbox
#define pn_funbox pn_u.name.funbox
#define pn_body pn_u.name.expr
#define pn_scopecoord pn_u.name.scopeCoord
#define pn_dflags pn_u.name.dflags
#define pn_blockid pn_u.name.blockid
#define pn_head pn_u.list.head
#define pn_tail pn_u.list.tail
#define pn_count pn_u.list.count
#define pn_xflags pn_u.list.xflags
#define pn_kid1 pn_u.ternary.kid1
#define pn_kid2 pn_u.ternary.kid2
#define pn_kid3 pn_u.ternary.kid3
#define pn_left pn_u.binary.left
#define pn_right pn_u.binary.right
#define pn_pval pn_u.binary.pval
#define pn_iflags pn_u.binary.iflags
#define pn_binary_obj pn_u.binary.objbox
#define pn_kid pn_u.unary.kid
#define pn_prologue pn_u.unary.prologue
#define pn_atom pn_u.name.atom
#define pn_objbox pn_u.name.objbox
#define pn_expr pn_u.name.expr
#define pn_lexdef pn_u.name.lexdef
#define pn_dval pn_u.number.value
protected:
void init(TokenKind type, JSOp op, ParseNodeArity arity) {
pn_type = type;
pn_op = op;
pn_arity = arity;
pn_parens = false;
MOZ_ASSERT(!pn_used);
MOZ_ASSERT(!pn_defn);
pn_next = pn_link = nullptr;
}
public:
/*
* If |left| is a list of the given kind/left-associative op, append
* |right| to it and return |left|. Otherwise return a [left, right] list.
*/
static ParseNode*
appendOrCreateList(ParseNodeKind kind, JSOp op, ParseNode* left, ParseNode* right,
FullParseHandler* handler, ParseContext<FullParseHandler>* pc);
inline PropertyName* name() const;
inline JSAtom* atom() const;
/*
* The pn_expr and lexdef members are arms of an unsafe union. Unless you
* know exactly what you're doing, use only the following methods to access
* them. For less overhead and assertions for protection, use pn->expr()
* and pn->lexdef(). Otherwise, use pn->maybeExpr() and pn->maybeLexDef().
*/
ParseNode* expr() const {
MOZ_ASSERT(!pn_used);
MOZ_ASSERT(pn_arity == PN_NAME || pn_arity == PN_CODE);
return pn_expr;
}
Definition* lexdef() const {
MOZ_ASSERT(pn_used || isDeoptimized());
MOZ_ASSERT(pn_arity == PN_NAME);
return pn_lexdef;
}
ParseNode* maybeExpr() { return pn_used ? nullptr : expr(); }
Definition* maybeLexDef() { return pn_used ? lexdef() : nullptr; }
Definition* resolve();
/* PN_CODE and PN_NAME pn_dflags bits. */
#define PND_LEXICAL 0x01 /* lexical (block-scoped) binding or use of a hoisted
let or const */
#define PND_CONST 0x02 /* const binding (orthogonal to let) */
#define PND_ASSIGNED 0x04 /* set if ever LHS of assignment */
#define PND_PLACEHOLDER 0x08 /* placeholder definition for lexdep */
#define PND_BOUND 0x10 /* bound to a stack or global slot */
#define PND_DEOPTIMIZED 0x20 /* former pn_used name node, pn_lexdef
still valid, but this use no longer
optimizable via an upvar opcode */
#define PND_CLOSED 0x40 /* variable is closed over */
#define PND_KNOWNALIASED 0x80 /* definition known to be aliased and
already has a translated pnk_scopecoord */
#define PND_IMPLICITARGUMENTS 0x100 /* the definition is a placeholder for
'arguments' that has been converted
into a definition after the function
body has been parsed. */
#define PND_IMPORT 0x200 /* the definition is a module import. */
static_assert(PND_IMPORT < (1 << NumDefinitionFlagBits), "Not enough bits");
/* Flags to propagate from uses to definition. */
#define PND_USE2DEF_FLAGS (PND_ASSIGNED | PND_CLOSED)
/* PN_LIST pn_xflags bits. */
#define PNX_FUNCDEFS 0x01 /* contains top-level function statements */
#define PNX_SETCALL 0x02 /* call expression in lvalue context */
#define PNX_ARRAYHOLESPREAD 0x04 /* one or more of
1. array initialiser has holes
2. array initializer has spread node */
#define PNX_NONCONST 0x08 /* initialiser has non-constants */
static_assert(PNX_NONCONST < (1 << NumListFlagBits), "Not enough bits");
uint32_t frameSlot() const {
MOZ_ASSERT(pn_arity == PN_CODE || pn_arity == PN_NAME);
return pn_scopecoord.slot();
}
bool functionIsHoisted() const {
MOZ_ASSERT(pn_arity == PN_CODE && getKind() == PNK_FUNCTION);
MOZ_ASSERT(isOp(JSOP_LAMBDA) || // lambda, genexpr
isOp(JSOP_LAMBDA_ARROW) || // arrow function
isOp(JSOP_DEFFUN) || // non-body-level function statement
isOp(JSOP_NOP) || // body-level function stmt in global code
isOp(JSOP_GETLOCAL) || // body-level function stmt in function code
isOp(JSOP_GETARG) || // body-level function redeclaring formal
isOp(JSOP_INITLEXICAL)); // block-level function stmt
return !isOp(JSOP_LAMBDA) && !isOp(JSOP_LAMBDA_ARROW) && !isOp(JSOP_DEFFUN);
}
/*
* True if this statement node could be a member of a Directive Prologue: an
* expression statement consisting of a single string literal.
*
* This considers only the node and its children, not its context. After
* parsing, check the node's pn_prologue flag to see if it is indeed part of
* a directive prologue.
*
* Note that a Directive Prologue can contain statements that cannot
* themselves be directives (string literals that include escape sequences
* or escaped newlines, say). This member function returns true for such
* nodes; we use it to determine the extent of the prologue.
*/
JSAtom* isStringExprStatement() const {
if (getKind() == PNK_SEMI) {
MOZ_ASSERT(pn_arity == PN_UNARY);
ParseNode* kid = pn_kid;
if (kid && kid->getKind() == PNK_STRING && !kid->pn_parens)
return kid->pn_atom;
}
return nullptr;
}
inline bool test(unsigned flag) const;
bool isLexical() const { return test(PND_LEXICAL) && !isUsed(); }
bool isConst() const { return test(PND_CONST); }
bool isPlaceholder() const { return test(PND_PLACEHOLDER); }
bool isDeoptimized() const { return test(PND_DEOPTIMIZED); }
bool isAssigned() const { return test(PND_ASSIGNED); }
bool isClosed() const { return test(PND_CLOSED); }
bool isBound() const { return test(PND_BOUND); }
bool isImplicitArguments() const { return test(PND_IMPLICITARGUMENTS); }
bool isHoistedLexicalUse() const { return test(PND_LEXICAL) && isUsed(); }
bool isKnownAliased() const { return test(PND_KNOWNALIASED); }
bool isImport() const { return test(PND_IMPORT); }
/* True if pn is a parsenode representing a literal constant. */
bool isLiteral() const {
return isKind(PNK_NUMBER) ||
isKind(PNK_STRING) ||
isKind(PNK_TRUE) ||
isKind(PNK_FALSE) ||
isKind(PNK_NULL);
}
/* Return true if this node appears in a Directive Prologue. */
bool isDirectivePrologueMember() const { return pn_prologue; }
ParseNode* generatorExpr() const {
MOZ_ASSERT(isKind(PNK_GENEXP));
ParseNode* callee = this->pn_head;
ParseNode* body = callee->pn_body;
MOZ_ASSERT(body->isKind(PNK_STATEMENTLIST));
MOZ_ASSERT(body->last()->isKind(PNK_LEXICALSCOPE) ||
body->last()->isKind(PNK_COMPREHENSIONFOR));
return body->last();
}
inline void markAsAssigned();
/*
* Compute a pointer to the last element in a singly-linked list. NB: list
* must be non-empty for correct PN_LAST usage -- this is asserted!
*/
ParseNode* last() const {
MOZ_ASSERT(pn_arity == PN_LIST);
MOZ_ASSERT(pn_count != 0);
return (ParseNode*)(uintptr_t(pn_tail) - offsetof(ParseNode, pn_next));
}
void initNumber(double value, DecimalPoint decimalPoint) {
MOZ_ASSERT(pn_arity == PN_NULLARY);
MOZ_ASSERT(getKind() == PNK_NUMBER);
pn_u.number.value = value;
pn_u.number.decimalPoint = decimalPoint;
}
void makeEmpty() {
MOZ_ASSERT(pn_arity == PN_LIST);
pn_head = nullptr;
pn_tail = &pn_head;
pn_count = 0;
pn_xflags = 0;
pn_blockid = 0;
}
void initList(ParseNode* pn) {
MOZ_ASSERT(pn_arity == PN_LIST);
if (pn->pn_pos.begin < pn_pos.begin)
pn_pos.begin = pn->pn_pos.begin;
pn_pos.end = pn->pn_pos.end;
pn_head = pn;
pn_tail = &pn->pn_next;
pn_count = 1;
pn_xflags = 0;
pn_blockid = 0;
}
void append(ParseNode* pn) {
MOZ_ASSERT(pn_arity == PN_LIST);
MOZ_ASSERT(pn->pn_pos.begin >= pn_pos.begin);
pn_pos.end = pn->pn_pos.end;
*pn_tail = pn;
pn_tail = &pn->pn_next;
pn_count++;
}
void prepend(ParseNode* pn) {
MOZ_ASSERT(pn_arity == PN_LIST);
pn->pn_next = pn_head;
pn_head = pn;
if (pn_tail == &pn_head)
pn_tail = &pn->pn_next;
pn_count++;
}
void checkListConsistency()
#ifndef DEBUG
{}
#endif
;
enum AllowConstantObjects {
DontAllowObjects = 0,
AllowObjects,
ForCopyOnWriteArray
};
bool getConstantValue(ExclusiveContext* cx, AllowConstantObjects allowObjects, MutableHandleValue vp,
Value* compare = nullptr, size_t ncompare = 0,
NewObjectKind newKind = TenuredObject);
inline bool isConstant();
template <class NodeType>
inline bool is() const {
return NodeType::test(*this);
}
/* Casting operations. */
template <class NodeType>
inline NodeType& as() {
MOZ_ASSERT(NodeType::test(*this));
return *static_cast<NodeType*>(this);
}
template <class NodeType>
inline const NodeType& as() const {
MOZ_ASSERT(NodeType::test(*this));
return *static_cast<const NodeType*>(this);
}
#ifdef DEBUG
void dump();
void dump(int indent);
#endif
};
struct NullaryNode : public ParseNode
{
NullaryNode(ParseNodeKind kind, const TokenPos& pos)
: ParseNode(kind, JSOP_NOP, PN_NULLARY, pos) {}
NullaryNode(ParseNodeKind kind, JSOp op, const TokenPos& pos)
: ParseNode(kind, op, PN_NULLARY, pos) {}
// This constructor is for a few mad uses in the emitter. It populates
// the pn_atom field even though that field belongs to a branch in pn_u
// that nullary nodes shouldn't use -- bogus.
NullaryNode(ParseNodeKind kind, JSOp op, const TokenPos& pos, JSAtom* atom)
: ParseNode(kind, op, PN_NULLARY, pos)
{
pn_atom = atom;
}
#ifdef DEBUG
void dump();
#endif
};
struct UnaryNode : public ParseNode
{
UnaryNode(ParseNodeKind kind, JSOp op, const TokenPos& pos, ParseNode* kid)
: ParseNode(kind, op, PN_UNARY, pos)
{
pn_kid = kid;
}
#ifdef DEBUG
void dump(int indent);
#endif
};
struct BinaryNode : public ParseNode
{
BinaryNode(ParseNodeKind kind, JSOp op, const TokenPos& pos, ParseNode* left, ParseNode* right)
: ParseNode(kind, op, PN_BINARY, pos)
{
pn_left = left;
pn_right = right;
}
BinaryNode(ParseNodeKind kind, JSOp op, ParseNode* left, ParseNode* right)
: ParseNode(kind, op, PN_BINARY, TokenPos::box(left->pn_pos, right->pn_pos))
{
pn_left = left;
pn_right = right;
}
#ifdef DEBUG
void dump(int indent);
#endif
};
struct BinaryObjNode : public ParseNode
{
BinaryObjNode(ParseNodeKind kind, JSOp op, const TokenPos& pos, ParseNode* left, ParseNode* right,
ObjectBox* objbox)
: ParseNode(kind, op, PN_BINARY_OBJ, pos)
{
pn_left = left;
pn_right = right;
pn_binary_obj = objbox;
}
#ifdef DEBUG
void dump(int indent);
#endif
};
struct TernaryNode : public ParseNode
{
TernaryNode(ParseNodeKind kind, JSOp op, ParseNode* kid1, ParseNode* kid2, ParseNode* kid3)
: ParseNode(kind, op, PN_TERNARY,
TokenPos((kid1 ? kid1 : kid2 ? kid2 : kid3)->pn_pos.begin,
(kid3 ? kid3 : kid2 ? kid2 : kid1)->pn_pos.end))
{
pn_kid1 = kid1;
pn_kid2 = kid2;
pn_kid3 = kid3;
}
TernaryNode(ParseNodeKind kind, JSOp op, ParseNode* kid1, ParseNode* kid2, ParseNode* kid3,
const TokenPos& pos)
: ParseNode(kind, op, PN_TERNARY, pos)
{
pn_kid1 = kid1;
pn_kid2 = kid2;
pn_kid3 = kid3;
}
#ifdef DEBUG
void dump(int indent);
#endif
};
struct ListNode : public ParseNode
{
ListNode(ParseNodeKind kind, const TokenPos& pos)
: ParseNode(kind, JSOP_NOP, PN_LIST, pos)
{
makeEmpty();
}
ListNode(ParseNodeKind kind, JSOp op, const TokenPos& pos)
: ParseNode(kind, op, PN_LIST, pos)
{
makeEmpty();
}
ListNode(ParseNodeKind kind, JSOp op, ParseNode* kid)
: ParseNode(kind, op, PN_LIST, kid->pn_pos)
{
initList(kid);
}
static bool test(const ParseNode& node) {
return node.isArity(PN_LIST);
}
#ifdef DEBUG
void dump(int indent);
#endif
};
struct CodeNode : public ParseNode
{
CodeNode(ParseNodeKind kind, const TokenPos& pos)
: ParseNode(kind, JSOP_NOP, PN_CODE, pos)
{
MOZ_ASSERT(kind == PNK_FUNCTION || kind == PNK_MODULE);
MOZ_ASSERT(!pn_body);
MOZ_ASSERT(!pn_objbox);
MOZ_ASSERT(pn_dflags == 0);
pn_scopecoord.makeFree();
}
public:
#ifdef DEBUG
void dump(int indent);
#endif
};
struct NameNode : public ParseNode
{
NameNode(ParseNodeKind kind, JSOp op, JSAtom* atom, uint32_t blockid,
const TokenPos& pos)
: ParseNode(kind, op, PN_NAME, pos)
{
pn_atom = atom;
pn_expr = nullptr;
pn_scopecoord.makeFree();
pn_dflags = 0;
pn_blockid = blockid;
MOZ_ASSERT(pn_blockid == blockid); // check for bitfield overflow
}
#ifdef DEBUG
void dump(int indent);
#endif
};
struct LexicalScopeNode : public ParseNode
{
LexicalScopeNode(ObjectBox* blockBox, const TokenPos& pos)
: ParseNode(PNK_LEXICALSCOPE, JSOP_NOP, PN_NAME, pos)
{
MOZ_ASSERT(!pn_expr);
MOZ_ASSERT(pn_dflags == 0);
MOZ_ASSERT(pn_blockid == 0);
pn_objbox = blockBox;
pn_scopecoord.makeFree();
}
LexicalScopeNode(ObjectBox* blockBox, ParseNode* blockNode)
: ParseNode(PNK_LEXICALSCOPE, JSOP_NOP, PN_NAME, blockNode->pn_pos)
{
pn_objbox = blockBox;
pn_expr = blockNode;
pn_blockid = blockNode->pn_blockid;
}
static bool test(const ParseNode& node) {
return node.isKind(PNK_LEXICALSCOPE);
}
};
class LabeledStatement : public ParseNode
{
public:
LabeledStatement(PropertyName* label, ParseNode* stmt, uint32_t begin)
: ParseNode(PNK_LABEL, JSOP_NOP, PN_NAME, TokenPos(begin, stmt->pn_pos.end))
{
pn_atom = label;
pn_expr = stmt;
}
PropertyName* label() const {
return pn_atom->asPropertyName();
}
ParseNode* statement() const {
return pn_expr;
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_LABEL);
MOZ_ASSERT_IF(match, node.isArity(PN_NAME));
MOZ_ASSERT_IF(match, node.isOp(JSOP_NOP));
return match;
}
};
// Inside a switch statement, a CaseClause is a case-label and the subsequent
// statements. The same node type is used for DefaultClauses. The only
// difference is that their caseExpression() is null.
class CaseClause : public BinaryNode
{
public:
CaseClause(ParseNode* expr, ParseNode* stmts, uint32_t begin)
: BinaryNode(PNK_CASE, JSOP_NOP, TokenPos(begin, stmts->pn_pos.end), expr, stmts) {}
ParseNode* caseExpression() const { return pn_left; }
bool isDefault() const { return !caseExpression(); }
ParseNode* statementList() const { return pn_right; }
// The next CaseClause in the same switch statement.
CaseClause* next() const { return pn_next ? &pn_next->as<CaseClause>() : nullptr; }
// Scratch space used by the emitter.
uint32_t offset() const { return pn_u.binary.offset; }
void setOffset(uint32_t u) { pn_u.binary.offset = u; }
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_CASE);
MOZ_ASSERT_IF(match, node.isArity(PN_BINARY));
MOZ_ASSERT_IF(match, node.isOp(JSOP_NOP));
return match;
}
};
class LoopControlStatement : public ParseNode
{
protected:
LoopControlStatement(ParseNodeKind kind, PropertyName* label, const TokenPos& pos)
: ParseNode(kind, JSOP_NOP, PN_NULLARY, pos)
{
MOZ_ASSERT(kind == PNK_BREAK || kind == PNK_CONTINUE);
pn_u.loopControl.label = label;
}
public:
/* Label associated with this break/continue statement, if any. */
PropertyName* label() const {
return pn_u.loopControl.label;
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_BREAK) || node.isKind(PNK_CONTINUE);
MOZ_ASSERT_IF(match, node.isArity(PN_NULLARY));
MOZ_ASSERT_IF(match, node.isOp(JSOP_NOP));
return match;
}
};
class BreakStatement : public LoopControlStatement
{
public:
BreakStatement(PropertyName* label, const TokenPos& pos)
: LoopControlStatement(PNK_BREAK, label, pos)
{ }
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_BREAK);
MOZ_ASSERT_IF(match, node.isArity(PN_NULLARY));
MOZ_ASSERT_IF(match, node.isOp(JSOP_NOP));
return match;
}
};
class ContinueStatement : public LoopControlStatement
{
public:
ContinueStatement(PropertyName* label, const TokenPos& pos)
: LoopControlStatement(PNK_CONTINUE, label, pos)
{ }
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_CONTINUE);
MOZ_ASSERT_IF(match, node.isArity(PN_NULLARY));
MOZ_ASSERT_IF(match, node.isOp(JSOP_NOP));
return match;
}
};
class DebuggerStatement : public ParseNode
{
public:
explicit DebuggerStatement(const TokenPos& pos)
: ParseNode(PNK_DEBUGGER, JSOP_NOP, PN_NULLARY, pos)
{ }
};
class ConditionalExpression : public ParseNode
{
public:
ConditionalExpression(ParseNode* condition, ParseNode* thenExpr, ParseNode* elseExpr)
: ParseNode(PNK_CONDITIONAL, JSOP_NOP, PN_TERNARY,
TokenPos(condition->pn_pos.begin, elseExpr->pn_pos.end))
{
MOZ_ASSERT(condition);
MOZ_ASSERT(thenExpr);
MOZ_ASSERT(elseExpr);
pn_u.ternary.kid1 = condition;
pn_u.ternary.kid2 = thenExpr;
pn_u.ternary.kid3 = elseExpr;
}
ParseNode& condition() const {
return *pn_u.ternary.kid1;
}
ParseNode& thenExpression() const {
return *pn_u.ternary.kid2;
}
ParseNode& elseExpression() const {
return *pn_u.ternary.kid3;
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_CONDITIONAL);
MOZ_ASSERT_IF(match, node.isArity(PN_TERNARY));
MOZ_ASSERT_IF(match, node.isOp(JSOP_NOP));
return match;
}
};
class ThisLiteral : public UnaryNode
{
public:
ThisLiteral(const TokenPos& pos, ParseNode* thisName)
: UnaryNode(PNK_THIS, JSOP_NOP, pos, thisName)
{ }
};
class NullLiteral : public ParseNode
{
public:
explicit NullLiteral(const TokenPos& pos) : ParseNode(PNK_NULL, JSOP_NULL, PN_NULLARY, pos) { }
};
class BooleanLiteral : public ParseNode
{
public:
BooleanLiteral(bool b, const TokenPos& pos)
: ParseNode(b ? PNK_TRUE : PNK_FALSE, b ? JSOP_TRUE : JSOP_FALSE, PN_NULLARY, pos)
{ }
};
class RegExpLiteral : public NullaryNode
{
public:
RegExpLiteral(ObjectBox* reobj, const TokenPos& pos)
: NullaryNode(PNK_REGEXP, JSOP_REGEXP, pos)
{
pn_objbox = reobj;
}
ObjectBox* objbox() const { return pn_objbox; }
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_REGEXP);
MOZ_ASSERT_IF(match, node.isArity(PN_NULLARY));
MOZ_ASSERT_IF(match, node.isOp(JSOP_REGEXP));
return match;
}
};
class PropertyAccess : public ParseNode
{
public:
PropertyAccess(ParseNode* lhs, PropertyName* name, uint32_t begin, uint32_t end)
: ParseNode(PNK_DOT, JSOP_NOP, PN_NAME, TokenPos(begin, end))
{
MOZ_ASSERT(lhs != nullptr);
MOZ_ASSERT(name != nullptr);
pn_u.name.expr = lhs;
pn_u.name.atom = name;
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_DOT);
MOZ_ASSERT_IF(match, node.isArity(PN_NAME));
return match;
}
ParseNode& expression() const {
return *pn_u.name.expr;
}
PropertyName& name() const {
return *pn_u.name.atom->asPropertyName();
}
bool isSuper() const {
// PNK_SUPERBASE cannot result from any expression syntax.
return expression().isKind(PNK_SUPERBASE);
}
};
class PropertyByValue : public ParseNode
{
public:
PropertyByValue(ParseNode* lhs, ParseNode* propExpr, uint32_t begin, uint32_t end)
: ParseNode(PNK_ELEM, JSOP_NOP, PN_BINARY, TokenPos(begin, end))
{
pn_u.binary.left = lhs;
pn_u.binary.right = propExpr;
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_ELEM);
MOZ_ASSERT_IF(match, node.isArity(PN_BINARY));
return match;
}
bool isSuper() const {
return pn_left->isKind(PNK_SUPERBASE);
}
};
/*
* A CallSiteNode represents the implicit call site object argument in a TaggedTemplate.
*/
struct CallSiteNode : public ListNode {
explicit CallSiteNode(uint32_t begin): ListNode(PNK_CALLSITEOBJ, TokenPos(begin, begin + 1)) {}
static bool test(const ParseNode& node) {
return node.isKind(PNK_CALLSITEOBJ);
}
bool getRawArrayValue(ExclusiveContext* cx, MutableHandleValue vp) {
return pn_head->getConstantValue(cx, AllowObjects, vp);
}
};
struct ClassMethod : public BinaryNode {
/*
* Method defintions often keep a name and function body that overlap,
* so explicitly define the beginning and end here.
*/
ClassMethod(ParseNode* name, ParseNode* body, JSOp op, bool isStatic)
: BinaryNode(PNK_CLASSMETHOD, op, TokenPos(name->pn_pos.begin, body->pn_pos.end), name, body)
{
pn_u.binary.isStatic = isStatic;
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_CLASSMETHOD);
MOZ_ASSERT_IF(match, node.isArity(PN_BINARY));
return match;
}
ParseNode& name() const {
return *pn_u.binary.left;
}
ParseNode& method() const {
return *pn_u.binary.right;
}
bool isStatic() const {
return pn_u.binary.isStatic;
}
};
struct ClassNames : public BinaryNode {
ClassNames(ParseNode* outerBinding, ParseNode* innerBinding, const TokenPos& pos)
: BinaryNode(PNK_CLASSNAMES, JSOP_NOP, pos, outerBinding, innerBinding)
{
MOZ_ASSERT_IF(outerBinding, outerBinding->isKind(PNK_NAME));
MOZ_ASSERT(innerBinding->isKind(PNK_NAME));
MOZ_ASSERT_IF(outerBinding, innerBinding->pn_atom == outerBinding->pn_atom);
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_CLASSNAMES);
MOZ_ASSERT_IF(match, node.isArity(PN_BINARY));
return match;
}
/*
* Classes require two definitions: The first "outer" binding binds the
* class into the scope in which it was declared. the outer binding is a
* mutable lexial binding. The second "inner" binding binds the class by
* name inside a block in which the methods are evaulated. It is immutable,
* giving the methods access to the static members of the class even if
* the outer binding has been overwritten.
*/
ParseNode* outerBinding() const {
return pn_u.binary.left;
}
ParseNode* innerBinding() const {
return pn_u.binary.right;
}
};
struct ClassNode : public TernaryNode {
ClassNode(ParseNode* names, ParseNode* heritage, ParseNode* methodsOrBlock)
: TernaryNode(PNK_CLASS, JSOP_NOP, names, heritage, methodsOrBlock)
{
MOZ_ASSERT_IF(names, names->is<ClassNames>());
MOZ_ASSERT(methodsOrBlock->is<LexicalScopeNode>() ||
methodsOrBlock->isKind(PNK_CLASSMETHODLIST));
}
static bool test(const ParseNode& node) {
bool match = node.isKind(PNK_CLASS);
MOZ_ASSERT_IF(match, node.isArity(PN_TERNARY));
return match;
}
ClassNames* names() const {
return pn_kid1 ? &pn_kid1->as<ClassNames>() : nullptr;
}
ParseNode* heritage() const {
return pn_kid2;
}
ParseNode* methodList() const {
if (pn_kid3->isKind(PNK_CLASSMETHODLIST))
return pn_kid3;
MOZ_ASSERT(pn_kid3->is<LexicalScopeNode>());
ParseNode* list = pn_kid3->pn_expr;
MOZ_ASSERT(list->isKind(PNK_CLASSMETHODLIST));
return list;
}
ObjectBox* scopeObjectBox() const {
MOZ_ASSERT(pn_kid3->is<LexicalScopeNode>());
return pn_kid3->pn_objbox;
}
};
#ifdef DEBUG
void DumpParseTree(ParseNode* pn, int indent = 0);
#endif
/*
* js::Definition is a degenerate subtype of the PN_FUNC and PN_NAME variants
* of js::ParseNode, allocated only for function, var, const, and let
* declarations that define truly lexical bindings. This means that a child of
* a PNK_VAR list may be a Definition as well as a ParseNode. The pn_defn bit
* is set for all Definitions, clear otherwise.
*
* In an upvars list, defn->resolve() is the outermost definition the
* name may reference. If a with block or a function that calls eval encloses
* the use, the name may end up referring to something else at runtime.
*
* Note that not all var declarations are definitions: JS allows multiple var
* declarations in a function or script, but only the first creates the hoisted
* binding. JS programmers do redeclare variables for good refactoring reasons,
* for example:
*
* function foo() {
* ...
* for (var i ...) ...;
* ...
* for (var i ...) ...;
* ...
* }
*
* Not all definitions bind lexical variables, alas. In global and eval code
* var may re-declare a pre-existing property having any attributes, with or
* without JSPROP_PERMANENT. In eval code, indeed, ECMA-262 Editions 1 through
* 3 require function and var to bind deletable bindings. Global vars thus are
* properties of the global object, so they can be aliased even if they can't
* be deleted.
*
* Only bindings within function code may be treated as lexical, of course with
* the caveat that hoisting means use before initialization is allowed. We deal
* with use before declaration in one pass as follows (error checking elided):
*
* for (each use of unqualified name x in parse order) {
* if (this use of x is a declaration) {
* if (x in pc->decls) { // redeclaring
* pn = allocate a PN_NAME ParseNode;
* } else { // defining
* dn = lookup x in pc->lexdeps;
* if (dn) // use before def
* remove x from pc->lexdeps;
* else // def before use
* dn = allocate a PN_NAME Definition;
* map x to dn via pc->decls;
* pn = dn;
* }
* insert pn into its parent PNK_VAR/PNK_CONST list;
* } else {
* pn = allocate a ParseNode for this reference to x;
* dn = lookup x in pc's lexical scope chain;
* if (!dn) {
* dn = lookup x in pc->lexdeps;
* if (!dn) {
* dn = pre-allocate a Definition for x;
* map x to dn in pc->lexdeps;
* }
* }
* append pn to dn's use chain;
* }
* }
*
* See frontend/BytecodeEmitter.h for js::ParseContext and its top*Stmt,
* decls, and lexdeps members.
*
* Notes:
*
* 0. To avoid bloating ParseNode, we steal a bit from pn_arity for pn_defn
* and set it on a ParseNode instead of allocating a Definition.
*
* 1. Due to hoisting, a definition cannot be eliminated even if its "Variable
* statement" (ECMA-262 12.2) can be proven to be dead code. RecycleTree in
* ParseNode.cpp will not recycle a node whose pn_defn bit is set.
*
* 2. "lookup x in pc's lexical scope chain" gives up on def/use chaining if a
* with statement is found along the the scope chain, which includes pc,
* pc->parent, etc. Thus we eagerly connect an inner function's use of an
* outer's var x if the var x was parsed before the inner function.
*
* 3. A use may be eliminated as dead by the constant folder, which therefore
* must remove the dead name node from its singly-linked use chain, which
* would mean hashing to find the definition node and searching to update
* the pn_link pointing at the use to be removed. This is costly, so as for
* dead definitions, we do not recycle dead pn_used nodes.
*
* At the end of parsing a function body or global or eval program, pc->lexdeps
* holds the lexical dependencies of the parsed unit. The name to def/use chain
* mappings are then merged into the parent pc->lexdeps.
*
* Thus if a later var x is parsed in the outer function satisfying an earlier
* inner function's use of x, we will remove dn from pc->lexdeps and re-use it
* as the new definition node in the outer function's parse tree.
*
* When the compiler unwinds from the outermost pc, pc->lexdeps contains the
* definition nodes with use chains for all free variables. These are either
* global variables or reference errors.
*/
struct Definition : public ParseNode
{
bool isFreeVar() const {
MOZ_ASSERT(isDefn());
return pn_scopecoord.isFree();
}
enum Kind {
MISSING = 0,
VAR,
CONSTANT,
LET,
ARG,
NAMED_LAMBDA,
PLACEHOLDER,
IMPORT
};
static bool test(const ParseNode& pn) { return pn.isDefn(); }
bool canHaveInitializer() { return int(kind()) <= int(ARG); }
static const char* kindString(Kind kind);
Kind kind() {
if (getKind() == PNK_FUNCTION) {
if (isOp(JSOP_GETARG))
return ARG;
if (isOp(JSOP_INITLEXICAL))
return LET;
return VAR;
}
MOZ_ASSERT(getKind() == PNK_NAME);
if (isOp(JSOP_CALLEE))
return NAMED_LAMBDA;
if (isPlaceholder())
return PLACEHOLDER;
if (isOp(JSOP_GETARG))
return ARG;
if (isImport())
return IMPORT;
if (isLexical())
return isConst() ? CONSTANT : LET;
return VAR;
}
};
class ParseNodeAllocator
{
public:
explicit ParseNodeAllocator(ExclusiveContext* cx, LifoAlloc& alloc)
: cx(cx), alloc(alloc), freelist(nullptr)
{}
void* allocNode();
void freeNode(ParseNode* pn);
ParseNode* freeTree(ParseNode* pn);
void prepareNodeForMutation(ParseNode* pn);
private:
ExclusiveContext* cx;
LifoAlloc& alloc;
ParseNode* freelist;
};
inline bool
ParseNode::test(unsigned flag) const
{
MOZ_ASSERT(pn_defn || pn_arity == PN_CODE || pn_arity == PN_NAME);
#ifdef DEBUG
if ((flag & PND_ASSIGNED) && pn_defn && !(pn_dflags & flag)) {
for (ParseNode* pn = ((Definition*) this)->dn_uses; pn; pn = pn->pn_link) {
MOZ_ASSERT(!pn->pn_defn);
MOZ_ASSERT(!(pn->pn_dflags & flag));
}
}
#endif
return !!(pn_dflags & flag);
}
inline void
ParseNode::markAsAssigned()
{
MOZ_ASSERT(CodeSpec[pn_op].format & JOF_NAME);
if (isUsed())
pn_lexdef->pn_dflags |= PND_ASSIGNED;
pn_dflags |= PND_ASSIGNED;
}
inline Definition*
ParseNode::resolve()
{
if (isDefn())
return (Definition*)this;
MOZ_ASSERT(lexdef()->isDefn());
return (Definition*)lexdef();
}
inline bool
ParseNode::isConstant()
{
switch (pn_type) {
case PNK_NUMBER:
case PNK_STRING:
case PNK_TEMPLATE_STRING:
case PNK_NULL:
case PNK_FALSE:
case PNK_TRUE:
return true;
case PNK_ARRAY:
case PNK_OBJECT:
MOZ_ASSERT(isOp(JSOP_NEWINIT));
return !(pn_xflags & PNX_NONCONST);
default:
return false;
}
}
class ObjectBox
{
public:
JSObject* object;
ObjectBox(JSObject* object, ObjectBox* traceLink);
bool isFunctionBox() { return object->is<JSFunction>(); }
FunctionBox* asFunctionBox();
bool isModuleBox();
ModuleBox* asModuleBox();
virtual void trace(JSTracer* trc);
static void TraceList(JSTracer* trc, ObjectBox* listHead);
protected:
friend struct CGObjectList;
ObjectBox* traceLink;
ObjectBox* emitLink;
ObjectBox(JSFunction* function, ObjectBox* traceLink);
};
enum ParseReportKind
{
ParseError,
ParseWarning,
ParseExtraWarning,
ParseStrictError
};
enum FunctionSyntaxKind
{
Expression,
Statement,
Arrow,
Method,
ClassConstructor,
DerivedClassConstructor,
Getter,
GetterNoExpressionClosure,
Setter,
SetterNoExpressionClosure
};
static inline bool
IsConstructorKind(FunctionSyntaxKind kind)
{
return kind == ClassConstructor || kind == DerivedClassConstructor;
}
static inline bool
IsGetterKind(FunctionSyntaxKind kind)
{
return kind == Getter || kind == GetterNoExpressionClosure;
}
static inline bool
IsSetterKind(FunctionSyntaxKind kind)
{
return kind == Setter || kind == SetterNoExpressionClosure;
}
static inline ParseNode*
FunctionArgsList(ParseNode* fn, unsigned* numFormals)
{
MOZ_ASSERT(fn->isKind(PNK_FUNCTION));
ParseNode* argsBody = fn->pn_body;
MOZ_ASSERT(argsBody->isKind(PNK_ARGSBODY));
*numFormals = argsBody->pn_count;
if (*numFormals > 0 && argsBody->last()->isKind(PNK_STATEMENTLIST))
(*numFormals)--;
MOZ_ASSERT(argsBody->isArity(PN_LIST));
return argsBody->pn_head;
}
} /* namespace frontend */
} /* namespace js */
#endif /* frontend_ParseNode_h */
