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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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* vim: set ts=8 sw=4 et tw=79:
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* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* The Original Code is Mozilla Communicator client code, released
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* The Initial Developer of the Original Code is
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* Netscape Communications Corporation.
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* Portions created by the Initial Developer are Copyright (C) 1998
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* the Initial Developer. All Rights Reserved.
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* Alternatively, the contents of this file may be used under the terms of
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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* ***** END LICENSE BLOCK ***** */
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* JS bytecode generation.
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* NB: If you add enumerators for scope statements, add them between STMT_WITH
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* and STMT_CATCH, or you will break the STMT_TYPE_IS_SCOPE macro. If you add
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* non-looping statement enumerators, add them before STMT_DO_LOOP or you will
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* break the STMT_TYPE_IS_LOOP macro.
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* Also remember to keep the statementName array in jsemit.c in sync.
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typedef enum JSStmtType {
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STMT_LABEL, /* labeled statement: L: s */
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STMT_IF, /* if (then) statement */
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STMT_ELSE, /* else clause of if statement */
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STMT_SEQ, /* synthetic sequence of statements */
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STMT_BLOCK, /* compound statement: { s1[;... sN] } */
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STMT_SWITCH, /* switch statement */
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STMT_WITH, /* with statement */
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STMT_CATCH, /* catch block */
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STMT_TRY, /* try block */
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STMT_FINALLY, /* finally block */
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STMT_SUBROUTINE, /* gosub-target subroutine body */
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STMT_DO_LOOP, /* do/while loop statement */
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STMT_FOR_LOOP, /* for loop statement */
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STMT_FOR_IN_LOOP, /* for/in loop statement */
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STMT_WHILE_LOOP, /* while loop statement */
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#define STMT_TYPE_IN_RANGE(t,b,e) ((uint)((t) - (b)) <= (uintN)((e) - (b)))
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* A comment on the encoding of the JSStmtType enum and type-testing macros:
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* STMT_TYPE_MAYBE_SCOPE tells whether a statement type is always, or may
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* become, a lexical scope. It therefore includes block and switch (the two
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* low-numbered "maybe" scope types) and excludes with (with has dynamic scope
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* pending the "reformed with" in ES4/JS2). It includes all try-catch-finally
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* types, which are high-numbered maybe-scope types.
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* STMT_TYPE_LINKS_SCOPE tells whether a JSStmtInfo of the given type eagerly
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* links to other scoping statement info records. It excludes the two early
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* "maybe" types, block and switch, as well as the try and both finally types,
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* since try and the other trailing maybe-scope types don't need block scope
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* unless they contain let declarations.
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* We treat WITH as a static scope because it prevents lexical binding from
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* continuing further up the static scope chain. With the lost "reformed with"
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* proposal for ES4, we would be able to model it statically, too.
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#define STMT_TYPE_MAYBE_SCOPE(type) \
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(type != STMT_WITH && \
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STMT_TYPE_IN_RANGE(type, STMT_BLOCK, STMT_SUBROUTINE))
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#define STMT_TYPE_LINKS_SCOPE(type) \
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STMT_TYPE_IN_RANGE(type, STMT_WITH, STMT_CATCH)
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#define STMT_TYPE_IS_TRYING(type) \
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STMT_TYPE_IN_RANGE(type, STMT_TRY, STMT_SUBROUTINE)
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#define STMT_TYPE_IS_LOOP(type) ((type) >= STMT_DO_LOOP)
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#define STMT_MAYBE_SCOPE(stmt) STMT_TYPE_MAYBE_SCOPE((stmt)->type)
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#define STMT_LINKS_SCOPE(stmt) (STMT_TYPE_LINKS_SCOPE((stmt)->type) || \
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((stmt)->flags & SIF_SCOPE))
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#define STMT_IS_TRYING(stmt) STMT_TYPE_IS_TRYING((stmt)->type)
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#define STMT_IS_LOOP(stmt) STMT_TYPE_IS_LOOP((stmt)->type)
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typedef struct JSStmtInfo JSStmtInfo;
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uint16 type; /* statement type */
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uint16 flags; /* flags, see below */
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uint32 blockid; /* for simplified dominance computation */
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ptrdiff_t update; /* loop update offset (top if none) */
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ptrdiff_t breaks; /* offset of last break in loop */
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ptrdiff_t continues; /* offset of last continue in loop */
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JSAtom *label; /* name of LABEL */
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JSObjectBox *blockBox; /* block scope object */
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JSStmtInfo *down; /* info for enclosing statement */
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JSStmtInfo *downScope; /* next enclosing lexical scope */
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#define SIF_SCOPE 0x0001 /* statement has its own lexical scope */
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#define SIF_BODY_BLOCK 0x0002 /* STMT_BLOCK type is a function body */
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#define SIF_FOR_BLOCK 0x0004 /* for (let ...) induced block scope */
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* To reuse space in JSStmtInfo, rename breaks and continues for use during
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* try/catch/finally code generation and backpatching. To match most common
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* use cases, the macro argument is a struct, not a struct pointer. Only a
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* loop, switch, or label statement info record can have breaks and continues,
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* and only a for loop has an update backpatch chain, so it's safe to overlay
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* these for the "trying" JSStmtTypes.
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#define CATCHNOTE(stmt) ((stmt).update)
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#define GOSUBS(stmt) ((stmt).breaks)
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#define GUARDJUMP(stmt) ((stmt).continues)
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#define SET_STATEMENT_TOP(stmt, top) \
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((stmt)->update = (top), (stmt)->breaks = (stmt)->continues = (-1))
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#ifdef JS_SCOPE_DEPTH_METER
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# define JS_SCOPE_DEPTH_METERING(code) ((void) (code))
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# define JS_SCOPE_DEPTH_METERING_IF(cond, code) ((cond) ? (void) (code) : (void) 0)
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# define JS_SCOPE_DEPTH_METERING(code) ((void) 0)
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# define JS_SCOPE_DEPTH_METERING_IF(code, x) ((void) 0)
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#define TCF_COMPILING 0x01 /* JSTreeContext is JSCodeGenerator */
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#define TCF_IN_FUNCTION 0x02 /* parsing inside function body */
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#define TCF_RETURN_EXPR 0x04 /* function has 'return expr;' */
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#define TCF_RETURN_VOID 0x08 /* function has 'return;' */
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#define TCF_IN_FOR_INIT 0x10 /* parsing init expr of for; exclude 'in' */
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#define TCF_FUN_SETS_OUTER_NAME 0x20 /* function set outer name (lexical or free) */
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#define TCF_FUN_PARAM_ARGUMENTS 0x40 /* function has parameter named arguments */
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#define TCF_FUN_USES_ARGUMENTS 0x80 /* function uses arguments except as a
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#define TCF_FUN_HEAVYWEIGHT 0x100 /* function needs Call object per call */
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#define TCF_FUN_IS_GENERATOR 0x200 /* parsed yield statement in function */
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#define TCF_FUN_USES_OWN_NAME 0x400 /* named function expression that uses its
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#define TCF_HAS_FUNCTION_STMT 0x800 /* block contains a function statement */
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#define TCF_GENEXP_LAMBDA 0x1000 /* flag lambda from generator expression */
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#define TCF_COMPILE_N_GO 0x2000 /* compile-and-go mode of script, can
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optimize name references based on scope
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#define TCF_NO_SCRIPT_RVAL 0x4000 /* API caller does not want result value
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from global script */
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#define TCF_HAS_SHARPS 0x8000 /* source contains sharp defs or uses */
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* Set when parsing a declaration-like destructuring pattern. This
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* flag causes PrimaryExpr to create PN_NAME parse nodes for variable
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* references which are not hooked into any definition's use chain,
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* added to any tree context's AtomList, etc. etc. CheckDestructuring
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* will do that work later.
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* The comments atop CheckDestructuring explain the distinction
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* between assignment-like and declaration-like destructuring
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* patterns, and why they need to be treated differently.
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#define TCF_DECL_DESTRUCTURING 0x10000
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* A request flag passed to Compiler::compileScript and then down via
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* JSCodeGenerator to js_NewScriptFromCG, from script_compile_sub and any
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* kindred functions that need to make mutable scripts (even empty ones;
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* i.e., they can't share the const JSScript::emptyScript() singleton).
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#define TCF_NEED_MUTABLE_SCRIPT 0x20000
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* This function/global/eval code body contained a Use Strict Directive. Treat
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* certain strict warnings as errors, and forbid the use of 'with'. See also
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* TSF_STRICT_MODE_CODE, JSScript::strictModeCode, and JSREPORT_STRICT_ERROR.
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#define TCF_STRICT_MODE_CODE 0x40000
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/* bit 0x80000 is unused */
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* Flag signifying that the current function seems to be a constructor that
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* sets this.foo to define "methods", at least one of which can't be a null
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* closure, so we should avoid over-specializing property cache entries and
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* trace inlining guards to method function object identity, which will vary
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#define TCF_FUN_UNBRAND_THIS 0x100000
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* "Module pattern", i.e., a lambda that is immediately applied and the whole
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* of an expression statement.
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#define TCF_FUN_MODULE_PATTERN 0x200000
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* Flag to prevent a non-escaping function from being optimized into a null
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* closure (i.e., a closure that needs only its global object for free variable
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* resolution), because this function contains a closure that needs one or more
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* scope objects surrounding it (i.e., a Call object for an outer heavyweight
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* function). See bug 560234.
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#define TCF_FUN_ENTRAINS_SCOPES 0x400000
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/* The function calls 'eval'. */
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#define TCF_FUN_CALLS_EVAL 0x800000
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/* The function mutates a positional (non-destructuring) parameter. */
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#define TCF_FUN_MUTATES_PARAMETER 0x1000000
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* Compiling an eval() script.
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#define TCF_COMPILE_FOR_EVAL 0x2000000
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* The function or a function that encloses it may define new local names
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* at runtime through means other than calling eval.
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#define TCF_FUN_MIGHT_ALIAS_LOCALS 0x4000000
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* The script contains singleton initialiser JSOP_OBJECT.
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#define TCF_HAS_SINGLETONS 0x8000000
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* Some enclosing scope is a with-statement or E4X filter-expression.
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#define TCF_IN_WITH 0x10000000
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* Flags to check for return; vs. return expr; in a function.
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#define TCF_RETURN_FLAGS (TCF_RETURN_EXPR | TCF_RETURN_VOID)
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* Sticky deoptimization flags to propagate from FunctionBody.
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#define TCF_FUN_FLAGS (TCF_FUN_SETS_OUTER_NAME | \
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TCF_FUN_USES_ARGUMENTS | \
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TCF_FUN_PARAM_ARGUMENTS | \
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TCF_FUN_HEAVYWEIGHT | \
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TCF_FUN_IS_GENERATOR | \
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TCF_FUN_USES_OWN_NAME | \
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TCF_FUN_CALLS_EVAL | \
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TCF_FUN_MIGHT_ALIAS_LOCALS | \
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TCF_FUN_MUTATES_PARAMETER | \
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TCF_STRICT_MODE_CODE)
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struct JSTreeContext { /* tree context for semantic checks */
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uint32 flags; /* statement state flags, see above */
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uint32 bodyid; /* block number of program/function body */
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uint32 blockidGen; /* preincremented block number generator */
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JSStmtInfo *topStmt; /* top of statement info stack */
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JSStmtInfo *topScopeStmt; /* top lexical scope statement */
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JSObjectBox *blockChainBox; /* compile time block scope chain (NB: one
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deeper than the topScopeStmt/downScope
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chain when in head of let block/expr) */
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JSParseNode *blockNode; /* parse node for a block with let declarations
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(block with its own lexical scope) */
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JSAtomList decls; /* function, const, and var declarations */
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js::Parser *parser; /* ptr to common parsing and lexing data */
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JSFunction *fun_; /* function to store argument and variable
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names when flags & TCF_IN_FUNCTION */
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JSObject *scopeChain_; /* scope chain object for the script */
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JSFunction *fun() const {
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JS_ASSERT(inFunction());
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void setFunction(JSFunction *fun) {
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JS_ASSERT(inFunction());
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JSObject *scopeChain() const {
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JS_ASSERT(!inFunction());
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void setScopeChain(JSObject *scopeChain) {
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JS_ASSERT(!inFunction());
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scopeChain_ = scopeChain;
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JSAtomList lexdeps; /* unresolved lexical name dependencies */
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JSTreeContext *parent; /* enclosing function or global context */
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uintN staticLevel; /* static compilation unit nesting level */
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JSFunctionBox *funbox; /* null or box for function we're compiling
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if (flags & TCF_IN_FUNCTION) and not in
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Compiler::compileFunctionBody */
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JSFunctionBox *functionList;
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JSParseNode *innermostWith; /* innermost WITH parse node */
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js::Bindings bindings; /* bindings in this code, including
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arguments if we're compiling a function */
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#ifdef JS_SCOPE_DEPTH_METER
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uint16 scopeDepth; /* current lexical scope chain depth */
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uint16 maxScopeDepth; /* maximum lexical scope chain depth */
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void trace(JSTracer *trc);
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JSTreeContext(js::Parser *prs)
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: flags(0), bodyid(0), blockidGen(0), topStmt(NULL), topScopeStmt(NULL),
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blockChainBox(NULL), blockNode(NULL), parser(prs), scopeChain_(NULL), parent(prs->tc),
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staticLevel(0), funbox(NULL), functionList(NULL), innermostWith(NULL), bindings(prs->context),
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JS_SCOPE_DEPTH_METERING(scopeDepth = maxScopeDepth = 0);
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* For functions the tree context is constructed and destructed a second
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* time during code generation. To avoid a redundant stats update in such
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* cases, we store uint16(-1) in maxScopeDepth.
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parser->tc = this->parent;
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JS_SCOPE_DEPTH_METERING_IF((maxScopeDepth != uint16(-1)),
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JS_BASIC_STATS_ACCUM(&parser
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->lexicalScopeDepthStats,
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uintN blockid() { return topStmt ? topStmt->blockid : bodyid; }
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JSObject *blockChain() {
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return blockChainBox ? blockChainBox->object : NULL;
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* True if we are at the topmost level of a entire script or function body.
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* For example, while parsing this code we would encounter f1 and f2 at
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* body level, but we would not encounter f3 or f4 at body level:
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* function f1() { function f2() { } }
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* if (cond) { function f3() { if (cond) { function f4() { } } } }
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bool atBodyLevel() { return !topStmt || (topStmt->flags & SIF_BODY_BLOCK); }
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/* Test whether we're in a statement of given type. */
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bool inStatement(JSStmtType type);
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bool inStrictMode() const {
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return flags & TCF_STRICT_MODE_CODE;
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inline bool needStrictChecks();
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* sharpSlotBase is -1 or first slot of pair for [sharpArray, sharpDepth].
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* The parser calls ensureSharpSlots to allocate these two stack locals.
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bool ensureSharpSlots();
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js::Compiler *compiler() { return (js::Compiler *)parser; }
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// Return true there is a generator function within |skip| lexical scopes
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// (going upward) from this context's lexical scope. Always return true if
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// this context is itself a generator.
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bool skipSpansGenerator(unsigned skip);
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bool compileAndGo() const { return flags & TCF_COMPILE_N_GO; }
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bool inFunction() const { return flags & TCF_IN_FUNCTION; }
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bool compiling() const { return flags & TCF_COMPILING; }
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inline JSCodeGenerator *asCodeGenerator();
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bool usesArguments() const {
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return flags & TCF_FUN_USES_ARGUMENTS;
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void noteCallsEval() {
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flags |= TCF_FUN_CALLS_EVAL;
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bool callsEval() const {
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return flags & TCF_FUN_CALLS_EVAL;
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void noteMightAliasLocals() {
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flags |= TCF_FUN_MIGHT_ALIAS_LOCALS;
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bool mightAliasLocals() const {
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return flags & TCF_FUN_MIGHT_ALIAS_LOCALS;
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void noteParameterMutation() {
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JS_ASSERT(inFunction());
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flags |= TCF_FUN_MUTATES_PARAMETER;
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bool mutatesParameter() const {
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JS_ASSERT(inFunction());
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return flags & TCF_FUN_MUTATES_PARAMETER;
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void noteArgumentsUse() {
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JS_ASSERT(inFunction());
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flags |= TCF_FUN_USES_ARGUMENTS;
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funbox->node->pn_dflags |= PND_FUNARG;
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bool needsEagerArguments() const {
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return inStrictMode() && ((usesArguments() && mutatesParameter()) || callsEval());
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* Return true if we need to check for conditions that elicit
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* JSOPTION_STRICT warnings or strict mode errors.
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inline bool JSTreeContext::needStrictChecks() {
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return parser->context->hasStrictOption() || inStrictMode();
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* Span-dependent instructions are jumps whose span (from the jump bytecode to
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* the jump target) may require 2 or 4 bytes of immediate operand.
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typedef struct JSSpanDep JSSpanDep;
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typedef struct JSJumpTarget JSJumpTarget;
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ptrdiff_t top; /* offset of first bytecode in an opcode */
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ptrdiff_t offset; /* offset - 1 within opcode of jump operand */
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ptrdiff_t before; /* original offset - 1 of jump operand */
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JSJumpTarget *target; /* tagged target pointer or backpatch delta */
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* Jump targets are stored in an AVL tree, for O(log(n)) lookup with targets
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* sorted by offset from left to right, so that targets after a span-dependent
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* instruction whose jump offset operand must be extended can be found quickly
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* and adjusted upward (toward higher offsets).
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struct JSJumpTarget {
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ptrdiff_t offset; /* offset of span-dependent jump target */
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int balance; /* AVL tree balance number */
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JSJumpTarget *kids[2]; /* left and right AVL tree child pointers */
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#define JT_OTHER_DIR(dir) (1 - (dir))
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#define JT_IMBALANCE(dir) (((dir) << 1) - 1)
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#define JT_DIR(imbalance) (((imbalance) + 1) >> 1)
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* Backpatch deltas are encoded in JSSpanDep.target if JT_TAG_BIT is clear,
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* so we can maintain backpatch chains when using span dependency records to
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* hold jump offsets that overflow 16 bits.
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#define JT_TAG_BIT ((jsword) 1)
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#define JT_UNTAG_SHIFT 1
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#define JT_SET_TAG(jt) ((JSJumpTarget *)((jsword)(jt) | JT_TAG_BIT))
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#define JT_CLR_TAG(jt) ((JSJumpTarget *)((jsword)(jt) & ~JT_TAG_BIT))
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#define JT_HAS_TAG(jt) ((jsword)(jt) & JT_TAG_BIT)
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#define BITS_PER_PTRDIFF (sizeof(ptrdiff_t) * JS_BITS_PER_BYTE)
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#define BITS_PER_BPDELTA (BITS_PER_PTRDIFF - 1 - JT_UNTAG_SHIFT)
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#define BPDELTA_MAX (((ptrdiff_t)1 << BITS_PER_BPDELTA) - 1)
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#define BPDELTA_TO_JT(bp) ((JSJumpTarget *)((bp) << JT_UNTAG_SHIFT))
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#define JT_TO_BPDELTA(jt) ((ptrdiff_t)((jsword)(jt) >> JT_UNTAG_SHIFT))
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#define SD_SET_TARGET(sd,jt) ((sd)->target = JT_SET_TAG(jt))
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#define SD_GET_TARGET(sd) (JS_ASSERT(JT_HAS_TAG((sd)->target)), \
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JT_CLR_TAG((sd)->target))
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#define SD_SET_BPDELTA(sd,bp) ((sd)->target = BPDELTA_TO_JT(bp))
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#define SD_GET_BPDELTA(sd) (JS_ASSERT(!JT_HAS_TAG((sd)->target)), \
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JT_TO_BPDELTA((sd)->target))
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/* Avoid asserting twice by expanding SD_GET_TARGET in the "then" clause. */
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#define SD_SPAN(sd,pivot) (SD_GET_TARGET(sd) \
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? JT_CLR_TAG((sd)->target)->offset - (pivot) \
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typedef struct JSTryNode JSTryNode;
537
struct JSCGObjectList {
538
uint32 length; /* number of emitted so far objects */
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JSObjectBox *lastbox; /* last emitted object */
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JSCGObjectList() : length(0), lastbox(NULL) {}
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uintN index(JSObjectBox *objbox);
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void finish(JSObjectArray *array);
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class JSGCConstList {
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js::Vector<js::Value> list;
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JSGCConstList(JSContext *cx) : list(cx) {}
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bool append(js::Value v) { return list.append(v); }
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size_t length() const { return list.length(); }
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void finish(JSConstArray *array);
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struct JSCodeGenerator : public JSTreeContext
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JSArenaPool *codePool; /* pointer to thread code arena pool */
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JSArenaPool *notePool; /* pointer to thread srcnote arena pool */
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void *codeMark; /* low watermark in cg->codePool */
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void *noteMark; /* low watermark in cg->notePool */
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jsbytecode *base; /* base of JS bytecode vector */
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jsbytecode *limit; /* one byte beyond end of bytecode */
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jsbytecode *next; /* pointer to next free bytecode */
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jssrcnote *notes; /* source notes, see below */
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uintN noteCount; /* number of source notes so far */
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uintN noteMask; /* growth increment for notes */
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ptrdiff_t lastNoteOffset; /* code offset for last source note */
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uintN currentLine; /* line number for tree-based srcnote gen */
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} prolog, main, *current;
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JSAtomList atomList; /* literals indexed for mapping */
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uintN firstLine; /* first line, for js_NewScriptFromCG */
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intN stackDepth; /* current stack depth in script frame */
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uintN maxStackDepth; /* maximum stack depth so far */
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uintN ntrynotes; /* number of allocated so far try notes */
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JSTryNode *lastTryNode; /* the last allocated try node */
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JSSpanDep *spanDeps; /* span dependent instruction records */
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JSJumpTarget *jumpTargets; /* AVL tree of jump target offsets */
586
JSJumpTarget *jtFreeList; /* JT_LEFT-linked list of free structs */
587
uintN numSpanDeps; /* number of span dependencies */
588
uintN numJumpTargets; /* number of jump targets */
589
ptrdiff_t spanDepTodo; /* offset from main.base of potentially
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unoptimized spandeps */
592
uintN arrayCompDepth; /* stack depth of array in comprehension */
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uintN emitLevel; /* js_EmitTree recursion level */
596
typedef js::HashMap<JSAtom *, js::Value> ConstMap;
597
ConstMap constMap; /* compile time constants */
599
JSGCConstList constList; /* constants to be included with the script */
601
JSCGObjectList objectList; /* list of emitted objects */
602
JSCGObjectList regexpList; /* list of emitted regexp that will be
603
cloned during execution */
605
JSAtomList upvarList; /* map of atoms to upvar indexes */
606
JSUpvarArray upvarMap; /* indexed upvar pairs (JS_realloc'ed) */
608
typedef js::Vector<js::GlobalSlotArray::Entry, 16, js::ContextAllocPolicy> GlobalUseVector;
610
GlobalUseVector globalUses; /* per-script global uses */
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JSAtomList globalMap; /* per-script map of global name to globalUses vector */
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/* Vectors of pn_cookie slot values. */
614
typedef js::Vector<uint32, 8, js::ContextAllocPolicy> SlotVector;
615
SlotVector closedArgs;
616
SlotVector closedVars;
618
uint16 traceIndex; /* index for the next JSOP_TRACE instruction */
621
* Initialize cg to allocate bytecode space from codePool, source note
622
* space from notePool, and all other arena-allocated temporaries from
623
* parser->context->tempPool.
625
JSCodeGenerator(js::Parser *parser,
626
JSArenaPool *codePool, JSArenaPool *notePool,
631
* Release cg->codePool, cg->notePool, and parser->context->tempPool to
632
* marks set by JSCodeGenerator's ctor. Note that cgs are magic: they own
633
* the arena pool "tops-of-stack" space above their codeMark, noteMark, and
634
* tempMark points. This means you cannot alloc from tempPool and save the
635
* pointer beyond the next JSCodeGenerator destructor call.
640
* Adds a use of a variable that is statically known to exist on the
643
* The actual slot of the variable on the global object is not known
644
* until after compilation. Properties must be resolved before being
645
* added, to avoid aliasing properties that should be resolved. This makes
646
* slot prediction based on the global object's free slot impossible. So,
647
* we use the slot to index into cg->globalScope->defs, and perform a
648
* fixup of the script at the very end of compilation.
650
* If the global use can be cached, |cookie| will be set to |slot|.
651
* Otherwise, |cookie| is set to the free cookie value.
653
bool addGlobalUse(JSAtom *atom, uint32 slot, js::UpvarCookie *cookie);
655
bool hasSharps() const {
656
bool rv = !!(flags & TCF_HAS_SHARPS);
657
JS_ASSERT((sharpSlotBase >= 0) == rv);
661
uintN sharpSlots() const {
662
return hasSharps() ? SHARP_NSLOTS : 0;
665
bool compilingForEval() const { return !!(flags & TCF_COMPILE_FOR_EVAL); }
666
JSVersion version() const { return parser->versionWithFlags(); }
668
bool shouldNoteClosedName(JSParseNode *pn);
670
bool checkSingletonContext() {
671
if (!compileAndGo() || inFunction())
673
for (JSStmtInfo *stmt = topStmt; stmt; stmt = stmt->down) {
674
if (STMT_IS_LOOP(stmt))
677
flags |= TCF_HAS_SINGLETONS;
682
#define CG_TS(cg) TS((cg)->parser)
684
#define CG_BASE(cg) ((cg)->current->base)
685
#define CG_LIMIT(cg) ((cg)->current->limit)
686
#define CG_NEXT(cg) ((cg)->current->next)
687
#define CG_CODE(cg,offset) (CG_BASE(cg) + (offset))
688
#define CG_OFFSET(cg) (CG_NEXT(cg) - CG_BASE(cg))
690
#define CG_NOTES(cg) ((cg)->current->notes)
691
#define CG_NOTE_COUNT(cg) ((cg)->current->noteCount)
692
#define CG_NOTE_MASK(cg) ((cg)->current->noteMask)
693
#define CG_LAST_NOTE_OFFSET(cg) ((cg)->current->lastNoteOffset)
694
#define CG_CURRENT_LINE(cg) ((cg)->current->currentLine)
696
#define CG_PROLOG_BASE(cg) ((cg)->prolog.base)
697
#define CG_PROLOG_LIMIT(cg) ((cg)->prolog.limit)
698
#define CG_PROLOG_NEXT(cg) ((cg)->prolog.next)
699
#define CG_PROLOG_CODE(cg,poff) (CG_PROLOG_BASE(cg) + (poff))
700
#define CG_PROLOG_OFFSET(cg) (CG_PROLOG_NEXT(cg) - CG_PROLOG_BASE(cg))
702
#define CG_SWITCH_TO_MAIN(cg) ((cg)->current = &(cg)->main)
703
#define CG_SWITCH_TO_PROLOG(cg) ((cg)->current = &(cg)->prolog)
705
inline JSCodeGenerator *
706
JSTreeContext::asCodeGenerator()
708
JS_ASSERT(compiling());
709
return static_cast<JSCodeGenerator *>(this);
716
js_Emit1(JSContext *cx, JSCodeGenerator *cg, JSOp op);
719
* Emit two bytecodes, an opcode (op) with a byte of immediate operand (op1).
722
js_Emit2(JSContext *cx, JSCodeGenerator *cg, JSOp op, jsbytecode op1);
725
* Emit three bytecodes, an opcode with two bytes of immediate operands.
728
js_Emit3(JSContext *cx, JSCodeGenerator *cg, JSOp op, jsbytecode op1,
732
* Emit five bytecodes, an opcode with two 16-bit immediates.
735
js_Emit5(JSContext *cx, JSCodeGenerator *cg, JSOp op, uint16 op1,
739
* Emit (1 + extra) bytecodes, for N bytes of op and its immediate operand.
742
js_EmitN(JSContext *cx, JSCodeGenerator *cg, JSOp op, size_t extra);
745
* Unsafe macro to call js_SetJumpOffset and return false if it does.
747
#define CHECK_AND_SET_JUMP_OFFSET_CUSTOM(cx,cg,pc,off,BAD_EXIT) \
749
if (!js_SetJumpOffset(cx, cg, pc, off)) { \
754
#define CHECK_AND_SET_JUMP_OFFSET(cx,cg,pc,off) \
755
CHECK_AND_SET_JUMP_OFFSET_CUSTOM(cx,cg,pc,off,return JS_FALSE)
757
#define CHECK_AND_SET_JUMP_OFFSET_AT_CUSTOM(cx,cg,off,BAD_EXIT) \
758
CHECK_AND_SET_JUMP_OFFSET_CUSTOM(cx, cg, CG_CODE(cg,off), \
759
CG_OFFSET(cg) - (off), BAD_EXIT)
761
#define CHECK_AND_SET_JUMP_OFFSET_AT(cx,cg,off) \
762
CHECK_AND_SET_JUMP_OFFSET_AT_CUSTOM(cx, cg, off, return JS_FALSE)
765
js_SetJumpOffset(JSContext *cx, JSCodeGenerator *cg, jsbytecode *pc,
769
* Push the C-stack-allocated struct at stmt onto the stmtInfo stack.
772
js_PushStatement(JSTreeContext *tc, JSStmtInfo *stmt, JSStmtType type,
776
* Push a block scope statement and link blockObj into tc->blockChain. To pop
777
* this statement info record, use js_PopStatement as usual, or if appropriate
778
* (if generating code), js_PopStatementCG.
781
js_PushBlockScope(JSTreeContext *tc, JSStmtInfo *stmt, JSObjectBox *blockBox,
785
* Pop tc->topStmt. If the top JSStmtInfo struct is not stack-allocated, it
786
* is up to the caller to free it.
789
js_PopStatement(JSTreeContext *tc);
792
* Like js_PopStatement(cg), also patch breaks and continues unless the top
793
* statement info record represents a try-catch-finally suite. May fail if a
794
* jump offset overflows.
797
js_PopStatementCG(JSContext *cx, JSCodeGenerator *cg);
800
* Define and lookup a primitive jsval associated with the const named by atom.
801
* js_DefineCompileTimeConstant analyzes the constant-folded initializer at pn
802
* and saves the const's value in cg->constList, if it can be used at compile
803
* time. It returns true unless an error occurred.
805
* If the initializer's value could not be saved, js_DefineCompileTimeConstant
806
* calls will return the undefined value. js_DefineCompileTimeConstant tries
807
* to find a const value memorized for atom, returning true with *vp set to a
808
* value other than undefined if the constant was found, true with *vp set to
809
* JSVAL_VOID if not found, and false on error.
812
js_DefineCompileTimeConstant(JSContext *cx, JSCodeGenerator *cg, JSAtom *atom,
816
* Find a lexically scoped variable (one declared by let, catch, or an array
817
* comprehension) named by atom, looking in tc's compile-time scopes.
819
* If a WITH statement is reached along the scope stack, return its statement
820
* info record, so callers can tell that atom is ambiguous. If slotp is not
821
* null, then if atom is found, set *slotp to its stack slot, otherwise to -1.
822
* This means that if slotp is not null, all the block objects on the lexical
823
* scope chain must have had their depth slots computed by the code generator,
824
* so the caller must be under js_EmitTree.
826
* In any event, directly return the statement info record in which atom was
827
* found. Otherwise return null.
830
js_LexicalLookup(JSTreeContext *tc, JSAtom *atom, jsint *slotp,
831
JSStmtInfo *stmt = NULL);
834
* Emit code into cg for the tree rooted at pn.
837
js_EmitTree(JSContext *cx, JSCodeGenerator *cg, JSParseNode *pn);
840
* Emit function code using cg for the tree rooted at body.
843
js_EmitFunctionScript(JSContext *cx, JSCodeGenerator *cg, JSParseNode *body);
846
* Source notes generated along with bytecode for decompiling and debugging.
847
* A source note is a uint8 with 5 bits of type and 3 of offset from the pc of
848
* the previous note. If 3 bits of offset aren't enough, extended delta notes
849
* (SRC_XDELTA) consisting of 2 set high order bits followed by 6 offset bits
850
* are emitted before the next note. Some notes have operand offsets encoded
851
* immediately after them, in note bytes or byte-triples.
853
* Source Note Extended Delta
854
* +7-6-5-4-3+2-1-0+ +7-6-5+4-3-2-1-0+
855
* |note-type|delta| |1 1| ext-delta |
856
* +---------+-----+ +---+-----------+
858
* At most one "gettable" note (i.e., a note of type other than SRC_NEWLINE,
859
* SRC_SETLINE, and SRC_XDELTA) applies to a given bytecode.
861
* NB: the js_SrcNoteSpec array in jsemit.c is indexed by this enum, so its
862
* initializers need to match the order here.
864
* Note on adding new source notes: every pair of bytecodes (A, B) where A and
865
* B have disjoint sets of source notes that could apply to each bytecode may
866
* reuse the same note type value for two notes (snA, snB) that have the same
867
* arity, offsetBias, and isSpanDep initializers in js_SrcNoteSpec. This is
868
* why SRC_IF and SRC_INITPROP have the same value below. For bad historical
869
* reasons, some bytecodes below that could be overlayed have not been, but
870
* before using SRC_EXTENDED, consider compressing the existing note types.
872
* Don't forget to update JSXDR_BYTECODE_VERSION in jsxdrapi.h for all such
873
* incompatible source note or other bytecode changes.
875
typedef enum JSSrcNoteType {
876
SRC_NULL = 0, /* terminates a note vector */
877
SRC_IF = 1, /* JSOP_IFEQ bytecode is from an if-then */
878
SRC_BREAK = 1, /* JSOP_GOTO is a break */
879
SRC_INITPROP = 1, /* disjoint meaning applied to JSOP_INITELEM or
880
to an index label in a regular (structuring)
881
or a destructuring object initialiser */
882
SRC_GENEXP = 1, /* JSOP_LAMBDA from generator expression */
883
SRC_IF_ELSE = 2, /* JSOP_IFEQ bytecode is from an if-then-else */
884
SRC_FOR_IN = 2, /* JSOP_GOTO to for-in loop condition from
885
before loop (same arity as SRC_IF_ELSE) */
886
SRC_FOR = 3, /* JSOP_NOP or JSOP_POP in for(;;) loop head */
887
SRC_WHILE = 4, /* JSOP_GOTO to for or while loop condition
888
from before loop, else JSOP_NOP at top of
890
SRC_TRACE = 4, /* For JSOP_TRACE; includes distance to loop end */
891
SRC_CONTINUE = 5, /* JSOP_GOTO is a continue, not a break;
892
also used on JSOP_ENDINIT if extra comma
893
at end of array literal: [1,2,,];
894
JSOP_DUP continuing destructuring pattern */
895
SRC_DECL = 6, /* type of a declaration (var, const, let*) */
896
SRC_DESTRUCT = 6, /* JSOP_DUP starting a destructuring assignment
897
operation, with SRC_DECL_* offset operand */
898
SRC_PCDELTA = 7, /* distance forward from comma-operator to
899
next POP, or from CONDSWITCH to first CASE
900
opcode, etc. -- always a forward delta */
901
SRC_GROUPASSIGN = 7, /* SRC_DESTRUCT variant for [a, b] = [c, d] */
902
SRC_ASSIGNOP = 8, /* += or another assign-op follows */
903
SRC_COND = 9, /* JSOP_IFEQ is from conditional ?: operator */
904
SRC_BRACE = 10, /* mandatory brace, for scope or to avoid
906
SRC_HIDDEN = 11, /* opcode shouldn't be decompiled */
907
SRC_PCBASE = 12, /* distance back from annotated getprop or
908
setprop op to left-most obj.prop.subprop
909
bytecode -- always a backward delta */
910
SRC_LABEL = 13, /* JSOP_NOP for label: with atomid immediate */
911
SRC_LABELBRACE = 14, /* JSOP_NOP for label: {...} begin brace */
912
SRC_ENDBRACE = 15, /* JSOP_NOP for label: {...} end brace */
913
SRC_BREAK2LABEL = 16, /* JSOP_GOTO for 'break label' with atomid */
914
SRC_CONT2LABEL = 17, /* JSOP_GOTO for 'continue label' with atomid */
915
SRC_SWITCH = 18, /* JSOP_*SWITCH with offset to end of switch,
916
2nd off to first JSOP_CASE if condswitch */
917
SRC_FUNCDEF = 19, /* JSOP_NOP for function f() with atomid */
918
SRC_CATCH = 20, /* catch block has guard */
919
SRC_EXTENDED = 21, /* extended source note, 32-159, in next byte */
920
SRC_NEWLINE = 22, /* bytecode follows a source newline */
921
SRC_SETLINE = 23, /* a file-absolute source line number note */
922
SRC_XDELTA = 24 /* 24-31 are for extended delta notes */
926
* Constants for the SRC_DECL source note. Note that span-dependent bytecode
927
* selection means that any SRC_DECL offset greater than SRC_DECL_LET may need
928
* to be adjusted, but these "offsets" are too small to span a span-dependent
929
* instruction, so can be used to denote distinct declaration syntaxes to the
932
* NB: the var_prefix array in jsopcode.c depends on these dense indexes from
933
* SRC_DECL_VAR through SRC_DECL_LET.
935
#define SRC_DECL_VAR 0
936
#define SRC_DECL_CONST 1
937
#define SRC_DECL_LET 2
938
#define SRC_DECL_NONE 3
940
#define SN_TYPE_BITS 5
941
#define SN_DELTA_BITS 3
942
#define SN_XDELTA_BITS 6
943
#define SN_TYPE_MASK (JS_BITMASK(SN_TYPE_BITS) << SN_DELTA_BITS)
944
#define SN_DELTA_MASK ((ptrdiff_t)JS_BITMASK(SN_DELTA_BITS))
945
#define SN_XDELTA_MASK ((ptrdiff_t)JS_BITMASK(SN_XDELTA_BITS))
947
#define SN_MAKE_NOTE(sn,t,d) (*(sn) = (jssrcnote) \
948
(((t) << SN_DELTA_BITS) \
949
| ((d) & SN_DELTA_MASK)))
950
#define SN_MAKE_XDELTA(sn,d) (*(sn) = (jssrcnote) \
951
((SRC_XDELTA << SN_DELTA_BITS) \
952
| ((d) & SN_XDELTA_MASK)))
954
#define SN_IS_XDELTA(sn) ((*(sn) >> SN_DELTA_BITS) >= SRC_XDELTA)
955
#define SN_TYPE(sn) ((JSSrcNoteType)(SN_IS_XDELTA(sn) \
957
: *(sn) >> SN_DELTA_BITS))
958
#define SN_SET_TYPE(sn,type) SN_MAKE_NOTE(sn, type, SN_DELTA(sn))
959
#define SN_IS_GETTABLE(sn) (SN_TYPE(sn) < SRC_NEWLINE)
961
#define SN_DELTA(sn) ((ptrdiff_t)(SN_IS_XDELTA(sn) \
962
? *(sn) & SN_XDELTA_MASK \
963
: *(sn) & SN_DELTA_MASK))
964
#define SN_SET_DELTA(sn,delta) (SN_IS_XDELTA(sn) \
965
? SN_MAKE_XDELTA(sn, delta) \
966
: SN_MAKE_NOTE(sn, SN_TYPE(sn), delta))
968
#define SN_DELTA_LIMIT ((ptrdiff_t)JS_BIT(SN_DELTA_BITS))
969
#define SN_XDELTA_LIMIT ((ptrdiff_t)JS_BIT(SN_XDELTA_BITS))
972
* Offset fields follow certain notes and are frequency-encoded: an offset in
973
* [0,0x7f] consumes one byte, an offset in [0x80,0x7fffff] takes three, and
974
* the high bit of the first byte is set.
976
#define SN_3BYTE_OFFSET_FLAG 0x80
977
#define SN_3BYTE_OFFSET_MASK 0x7f
979
typedef struct JSSrcNoteSpec {
980
const char *name; /* name for disassembly/debugging output */
981
int8 arity; /* number of offset operands */
982
uint8 offsetBias; /* bias of offset(s) from annotated pc */
983
int8 isSpanDep; /* 1 or -1 if offsets could span extended ops,
984
0 otherwise; sign tells span direction */
987
extern JS_FRIEND_DATA(JSSrcNoteSpec) js_SrcNoteSpec[];
988
extern JS_FRIEND_API(uintN) js_SrcNoteLength(jssrcnote *sn);
990
#define SN_LENGTH(sn) ((js_SrcNoteSpec[SN_TYPE(sn)].arity == 0) ? 1 \
991
: js_SrcNoteLength(sn))
992
#define SN_NEXT(sn) ((sn) + SN_LENGTH(sn))
994
/* A source note array is terminated by an all-zero element. */
995
#define SN_MAKE_TERMINATOR(sn) (*(sn) = SRC_NULL)
996
#define SN_IS_TERMINATOR(sn) (*(sn) == SRC_NULL)
999
* Append a new source note of the given type (and therefore size) to cg's
1000
* notes dynamic array, updating cg->noteCount. Return the new note's index
1001
* within the array pointed at by cg->current->notes. Return -1 if out of
1005
js_NewSrcNote(JSContext *cx, JSCodeGenerator *cg, JSSrcNoteType type);
1008
js_NewSrcNote2(JSContext *cx, JSCodeGenerator *cg, JSSrcNoteType type,
1012
js_NewSrcNote3(JSContext *cx, JSCodeGenerator *cg, JSSrcNoteType type,
1013
ptrdiff_t offset1, ptrdiff_t offset2);
1016
* NB: this function can add at most one extra extended delta note.
1019
js_AddToSrcNoteDelta(JSContext *cx, JSCodeGenerator *cg, jssrcnote *sn,
1023
* Get and set the offset operand identified by which (0 for the first, etc.).
1025
extern JS_FRIEND_API(ptrdiff_t)
1026
js_GetSrcNoteOffset(jssrcnote *sn, uintN which);
1029
js_SetSrcNoteOffset(JSContext *cx, JSCodeGenerator *cg, uintN index,
1030
uintN which, ptrdiff_t offset);
1033
* Finish taking source notes in cx's notePool, copying final notes to the new
1034
* stable store allocated by the caller and passed in via notes. Return false
1035
* on malloc failure, which means this function reported an error.
1037
* To compute the number of jssrcnotes to allocate and pass in via notes, use
1038
* the CG_COUNT_FINAL_SRCNOTES macro. This macro knows a lot about details of
1039
* js_FinishTakingSrcNotes, SO DON'T CHANGE jsemit.c's js_FinishTakingSrcNotes
1040
* FUNCTION WITHOUT CHECKING WHETHER THIS MACRO NEEDS CORRESPONDING CHANGES!
1042
#define CG_COUNT_FINAL_SRCNOTES(cg, cnt) \
1044
ptrdiff_t diff_ = CG_PROLOG_OFFSET(cg) - (cg)->prolog.lastNoteOffset; \
1045
cnt = (cg)->prolog.noteCount + (cg)->main.noteCount + 1; \
1046
if ((cg)->prolog.noteCount && \
1047
(cg)->prolog.currentLine != (cg)->firstLine) { \
1048
if (diff_ > SN_DELTA_MASK) \
1049
cnt += JS_HOWMANY(diff_ - SN_DELTA_MASK, SN_XDELTA_MASK); \
1050
cnt += 2 + (((cg)->firstLine > SN_3BYTE_OFFSET_MASK) << 1); \
1051
} else if (diff_ > 0) { \
1052
if (cg->main.noteCount) { \
1053
jssrcnote *sn_ = (cg)->main.notes; \
1054
diff_ -= SN_IS_XDELTA(sn_) \
1055
? SN_XDELTA_MASK - (*sn_ & SN_XDELTA_MASK) \
1056
: SN_DELTA_MASK - (*sn_ & SN_DELTA_MASK); \
1059
cnt += JS_HOWMANY(diff_, SN_XDELTA_MASK); \
1064
js_FinishTakingSrcNotes(JSContext *cx, JSCodeGenerator *cg, jssrcnote *notes);
1067
js_FinishTakingTryNotes(JSCodeGenerator *cg, JSTryNoteArray *array);
1071
#endif /* jsemit_h___ */
added
removed
deps/Windows-x86-deps/JS32ECMAv5/include/jsemit.h
