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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef jsopcode_h___
#define jsopcode_h___
/*
* JS bytecode definitions.
*/
#include <stddef.h>
#include "jsprvtd.h"
#include "jspubtd.h"
#include "jsutil.h"
JS_BEGIN_EXTERN_C
/*
* JS operation bytecodes.
*/
typedef enum JSOp {
#define OPDEF(op,val,name,token,length,nuses,ndefs,prec,format) \
op = val,
#include "jsopcode.tbl"
#undef OPDEF
JSOP_LIMIT
} JSOp;
/*
* JS bytecode formats.
*/
#define JOF_BYTE 0 /* single bytecode, no immediates */
#define JOF_JUMP 1 /* signed 16-bit jump offset immediate */
#define JOF_ATOM 2 /* unsigned 16-bit constant index */
#define JOF_UINT16 3 /* unsigned 16-bit immediate operand */
#define JOF_TABLESWITCH 4 /* table switch */
#define JOF_LOOKUPSWITCH 5 /* lookup switch */
#define JOF_QARG 6 /* quickened get/set function argument ops */
#define JOF_LOCAL 7 /* var or block-local variable */
#define JOF_SLOTATOM 8 /* uint16 slot + constant index */
#define JOF_JUMPX 9 /* signed 32-bit jump offset immediate */
#define JOF_TABLESWITCHX 10 /* extended (32-bit offset) table switch */
#define JOF_LOOKUPSWITCHX 11 /* extended (32-bit offset) lookup switch */
#define JOF_UINT24 12 /* extended unsigned 24-bit literal (index) */
#define JOF_UINT8 13 /* uint8 immediate, e.g. top 8 bits of 24-bit
atom index */
#define JOF_INT32 14 /* int32 immediate operand */
#define JOF_OBJECT 15 /* unsigned 16-bit object index */
#define JOF_SLOTOBJECT 16 /* uint16 slot index + object index */
#define JOF_REGEXP 17 /* unsigned 16-bit regexp index */
#define JOF_INT8 18 /* int8 immediate operand */
#define JOF_ATOMOBJECT 19 /* uint16 constant index + object index */
#define JOF_UINT16PAIR 20 /* pair of uint16 immediates */
#define JOF_TYPEMASK 0x001f /* mask for above immediate types */
#define JOF_NAME (1U<<5) /* name operation */
#define JOF_PROP (2U<<5) /* obj.prop operation */
#define JOF_ELEM (3U<<5) /* obj[index] operation */
#define JOF_XMLNAME (4U<<5) /* XML name: *, a::b, @a, @a::b, etc. */
#define JOF_VARPROP (5U<<5) /* x.prop for this, arg, var, or local x */
#define JOF_MODEMASK (7U<<5) /* mask for above addressing modes */
#define JOF_SET (1U<<8) /* set (i.e., assignment) operation */
#define JOF_DEL (1U<<9) /* delete operation */
#define JOF_DEC (1U<<10) /* decrement (--, not ++) opcode */
#define JOF_INC (2U<<10) /* increment (++, not --) opcode */
#define JOF_INCDEC (3U<<10) /* increment or decrement opcode */
#define JOF_POST (1U<<12) /* postorder increment or decrement */
#define JOF_FOR (1U<<13) /* for-in property op (akin to JOF_SET) */
#define JOF_ASSIGNING JOF_SET /* hint for JSClass.resolve, used for ops
that do simplex assignment */
#define JOF_DETECTING (1U<<14) /* object detection for JSNewResolveOp */
#define JOF_BACKPATCH (1U<<15) /* backpatch placeholder during codegen */
#define JOF_LEFTASSOC (1U<<16) /* left-associative operator */
#define JOF_DECLARING (1U<<17) /* var, const, or function declaration op */
#define JOF_INDEXBASE (1U<<18) /* atom segment base setting prefix op */
#define JOF_CALLOP (1U<<19) /* call operation that pushes function and
this */
#define JOF_PARENHEAD (1U<<20) /* opcode consumes value of expression in
parenthesized statement head */
#define JOF_INVOKE (1U<<21) /* JSOP_CALL, JSOP_NEW, JSOP_EVAL */
#define JOF_TMPSLOT (1U<<22) /* interpreter uses extra temporary slot
to root intermediate objects besides
the slots opcode uses */
#define JOF_TMPSLOT2 (2U<<22) /* interpreter uses extra 2 temporary slot
besides the slots opcode uses */
#define JOF_TMPSLOT_SHIFT 22
#define JOF_TMPSLOT_MASK (JS_BITMASK(2) << JOF_TMPSLOT_SHIFT)
#define JOF_SHARPSLOT (1U<<24) /* first immediate is uint16 stack slot no.
that needs fixup when in global code (see
JSCompiler::compileScript) */
/* Shorthands for type from format and type from opcode. */
#define JOF_TYPE(fmt) ((fmt) & JOF_TYPEMASK)
#define JOF_OPTYPE(op) JOF_TYPE(js_CodeSpec[op].format)
/* Shorthands for mode from format and mode from opcode. */
#define JOF_MODE(fmt) ((fmt) & JOF_MODEMASK)
#define JOF_OPMODE(op) JOF_MODE(js_CodeSpec[op].format)
#define JOF_TYPE_IS_EXTENDED_JUMP(t) \
((unsigned)((t) - JOF_JUMPX) <= (unsigned)(JOF_LOOKUPSWITCHX - JOF_JUMPX))
/*
* Immediate operand getters, setters, and bounds.
*/
/* Common uint16 immediate format helpers. */
#define UINT16_LEN 2
#define UINT16_HI(i) ((jsbytecode)((i) >> 8))
#define UINT16_LO(i) ((jsbytecode)(i))
#define GET_UINT16(pc) ((uintN)(((pc)[1] << 8) | (pc)[2]))
#define SET_UINT16(pc,i) ((pc)[1] = UINT16_HI(i), (pc)[2] = UINT16_LO(i))
#define UINT16_LIMIT ((uintN)1 << 16)
/* Short (2-byte signed offset) relative jump macros. */
#define JUMP_OFFSET_LEN 2
#define JUMP_OFFSET_HI(off) ((jsbytecode)((off) >> 8))
#define JUMP_OFFSET_LO(off) ((jsbytecode)(off))
#define GET_JUMP_OFFSET(pc) ((int16)GET_UINT16(pc))
#define SET_JUMP_OFFSET(pc,off) ((pc)[1] = JUMP_OFFSET_HI(off), \
(pc)[2] = JUMP_OFFSET_LO(off))
#define JUMP_OFFSET_MIN ((int16)0x8000)
#define JUMP_OFFSET_MAX ((int16)0x7fff)
/*
* When a short jump won't hold a relative offset, its 2-byte immediate offset
* operand is an unsigned index of a span-dependency record, maintained until
* code generation finishes -- after which some (but we hope not nearly all)
* span-dependent jumps must be extended (see OptimizeSpanDeps in jsemit.c).
*
* If the span-dependency record index overflows SPANDEP_INDEX_MAX, the jump
* offset will contain SPANDEP_INDEX_HUGE, indicating that the record must be
* found (via binary search) by its "before span-dependency optimization" pc
* offset (from script main entry point).
*/
#define GET_SPANDEP_INDEX(pc) ((uint16)GET_UINT16(pc))
#define SET_SPANDEP_INDEX(pc,i) ((pc)[1] = JUMP_OFFSET_HI(i), \
(pc)[2] = JUMP_OFFSET_LO(i))
#define SPANDEP_INDEX_MAX ((uint16)0xfffe)
#define SPANDEP_INDEX_HUGE ((uint16)0xffff)
/* Ultimately, if short jumps won't do, emit long (4-byte signed) offsets. */
#define JUMPX_OFFSET_LEN 4
#define JUMPX_OFFSET_B3(off) ((jsbytecode)((off) >> 24))
#define JUMPX_OFFSET_B2(off) ((jsbytecode)((off) >> 16))
#define JUMPX_OFFSET_B1(off) ((jsbytecode)((off) >> 8))
#define JUMPX_OFFSET_B0(off) ((jsbytecode)(off))
#define GET_JUMPX_OFFSET(pc) ((int32)(((pc)[1] << 24) | ((pc)[2] << 16) \
| ((pc)[3] << 8) | (pc)[4]))
#define SET_JUMPX_OFFSET(pc,off)((pc)[1] = JUMPX_OFFSET_B3(off), \
(pc)[2] = JUMPX_OFFSET_B2(off), \
(pc)[3] = JUMPX_OFFSET_B1(off), \
(pc)[4] = JUMPX_OFFSET_B0(off))
#define JUMPX_OFFSET_MIN ((int32)0x80000000)
#define JUMPX_OFFSET_MAX ((int32)0x7fffffff)
/*
* A literal is indexed by a per-script atom or object maps. Most scripts
* have relatively few literals, so the standard JOF_ATOM, JOF_OBJECT and
* JOF_REGEXP formats specifies a fixed 16 bits of immediate operand index.
* A script with more than 64K literals must wrap the bytecode into
* JSOP_INDEXBASE and JSOP_RESETBASE pair.
*/
#define INDEX_LEN 2
#define INDEX_HI(i) ((jsbytecode)((i) >> 8))
#define INDEX_LO(i) ((jsbytecode)(i))
#define GET_INDEX(pc) GET_UINT16(pc)
#define SET_INDEX(pc,i) ((pc)[1] = INDEX_HI(i), (pc)[2] = INDEX_LO(i))
#define GET_INDEXBASE(pc) (JS_ASSERT(*(pc) == JSOP_INDEXBASE), \
((uintN)((pc)[1])) << 16)
#define INDEXBASE_LEN 1
#define UINT24_HI(i) ((jsbytecode)((i) >> 16))
#define UINT24_MID(i) ((jsbytecode)((i) >> 8))
#define UINT24_LO(i) ((jsbytecode)(i))
#define GET_UINT24(pc) ((jsatomid)(((pc)[1] << 16) | \
((pc)[2] << 8) | \
(pc)[3]))
#define SET_UINT24(pc,i) ((pc)[1] = UINT24_HI(i), \
(pc)[2] = UINT24_MID(i), \
(pc)[3] = UINT24_LO(i))
#define GET_INT8(pc) ((jsint)(int8)(pc)[1])
#define GET_INT32(pc) ((jsint)(((uint32)((pc)[1]) << 24) | \
((uint32)((pc)[2]) << 16) | \
((uint32)((pc)[3]) << 8) | \
(uint32)(pc)[4]))
#define SET_INT32(pc,i) ((pc)[1] = (jsbytecode)((uint32)(i) >> 24), \
(pc)[2] = (jsbytecode)((uint32)(i) >> 16), \
(pc)[3] = (jsbytecode)((uint32)(i) >> 8), \
(pc)[4] = (jsbytecode)(uint32)(i))
/* Index limit is determined by SN_3BYTE_OFFSET_FLAG, see jsemit.h. */
#define INDEX_LIMIT_LOG2 23
#define INDEX_LIMIT ((uint32)1 << INDEX_LIMIT_LOG2)
/* Actual argument count operand format helpers. */
#define ARGC_HI(argc) UINT16_HI(argc)
#define ARGC_LO(argc) UINT16_LO(argc)
#define GET_ARGC(pc) GET_UINT16(pc)
#define ARGC_LIMIT UINT16_LIMIT
/* Synonyms for quick JOF_QARG and JOF_LOCAL bytecodes. */
#define GET_ARGNO(pc) GET_UINT16(pc)
#define SET_ARGNO(pc,argno) SET_UINT16(pc,argno)
#define ARGNO_LEN 2
#define ARGNO_LIMIT UINT16_LIMIT
#define GET_SLOTNO(pc) GET_UINT16(pc)
#define SET_SLOTNO(pc,varno) SET_UINT16(pc,varno)
#define SLOTNO_LEN 2
#define SLOTNO_LIMIT UINT16_LIMIT
struct JSCodeSpec {
int8 length; /* length including opcode byte */
int8 nuses; /* arity, -1 if variadic */
int8 ndefs; /* number of stack results */
uint8 prec; /* operator precedence */
uint32 format; /* immediate operand format */
};
extern const JSCodeSpec js_CodeSpec[];
extern uintN js_NumCodeSpecs;
extern const char *js_CodeName[];
extern const char js_EscapeMap[];
/*
* Return a GC'ed string containing the chars in str, with any non-printing
* chars or quotes (' or " as specified by the quote argument) escaped, and
* with the quote character at the beginning and end of the result string.
*/
extern JSString *
js_QuoteString(JSContext *cx, JSString *str, jschar quote);
/*
* JSPrinter operations, for printf style message formatting. The return
* value from js_GetPrinterOutput() is the printer's cumulative output, in
* a GC'ed string.
*
* strict is true if the context in which the output will appear has
* already been marked as strict, thus indicating that nested
* functions need not be re-marked with a strict directive. It should
* be false in the outermost printer.
*/
extern JSPrinter *
js_NewPrinter(JSContext *cx, const char *name, JSFunction *fun,
uintN indent, JSBool pretty, JSBool grouped, JSBool strict);
extern void
js_DestroyPrinter(JSPrinter *jp);
extern JSString *
js_GetPrinterOutput(JSPrinter *jp);
extern int
js_printf(JSPrinter *jp, const char *format, ...);
extern JSBool
js_puts(JSPrinter *jp, const char *s);
/*
* Get index operand from the bytecode using a bytecode analysis to deduce the
* the index register. This function is infallible, in spite of taking cx as
* its first parameter; it uses only cx->runtime when calling JS_GetTrapOpcode.
* The GET_*_FROM_BYTECODE macros that call it pick up cx from their caller's
* lexical environments.
*/
uintN
js_GetIndexFromBytecode(JSContext *cx, JSScript *script, jsbytecode *pc,
ptrdiff_t pcoff);
/*
* A slower version of GET_ATOM when the caller does not want to maintain
* the index segment register itself.
*/
#define GET_ATOM_FROM_BYTECODE(script, pc, pcoff, atom) \
JS_BEGIN_MACRO \
JS_ASSERT(*(pc) != JSOP_DOUBLE); \
uintN index_ = js_GetIndexFromBytecode(cx, (script), (pc), (pcoff)); \
JS_GET_SCRIPT_ATOM(script, pc, index_, atom); \
JS_END_MACRO
/*
* Variant for getting a double atom when we might be in an imacro. Bytecodes
* with literals that are only ever doubles must use this macro, and never use
* GET_ATOM_FROM_BYTECODE or JS_GET_SCRIPT_ATOM.
*
* Unfortunately some bytecodes such as JSOP_LOOKUPSWITCH have immediates that
* might be string or double atoms. Those opcodes cannot be used from imacros.
* See the assertions in the JSOP_DOUBLE and JSOP_LOOKUPSWTICH* opcode cases in
* jsops.cpp.
*/
#define GET_DOUBLE_FROM_BYTECODE(script, pc, pcoff, atom) \
JS_BEGIN_MACRO \
uintN index_ = js_GetIndexFromBytecode(cx, (script), (pc), (pcoff)); \
JS_ASSERT(index_ < (script)->atomMap.length); \
(atom) = (script)->atomMap.vector[index_]; \
JS_ASSERT(ATOM_IS_DOUBLE(atom)); \
JS_END_MACRO
#define GET_OBJECT_FROM_BYTECODE(script, pc, pcoff, obj) \
JS_BEGIN_MACRO \
uintN index_ = js_GetIndexFromBytecode(cx, (script), (pc), (pcoff)); \
obj = (script)->getObject(index_); \
JS_END_MACRO
#define GET_FUNCTION_FROM_BYTECODE(script, pc, pcoff, fun) \
JS_BEGIN_MACRO \
uintN index_ = js_GetIndexFromBytecode(cx, (script), (pc), (pcoff)); \
fun = (script)->getFunction(index_); \
JS_END_MACRO
#define GET_REGEXP_FROM_BYTECODE(script, pc, pcoff, obj) \
JS_BEGIN_MACRO \
uintN index_ = js_GetIndexFromBytecode(cx, (script), (pc), (pcoff)); \
obj = (script)->getRegExp(index_); \
JS_END_MACRO
/*
* Get the length of variable-length bytecode like JSOP_TABLESWITCH.
*/
extern uintN
js_GetVariableBytecodeLength(jsbytecode *pc);
/*
* Find the number of stack slots used by a variadic opcode such as JSOP_CALL
* or JSOP_NEWARRAY (for such ops, JSCodeSpec.nuses is -1).
*/
extern uintN
js_GetVariableStackUses(JSOp op, jsbytecode *pc);
/*
* Find the number of stack slots defined by JSOP_ENTERBLOCK (for this op,
* JSCodeSpec.ndefs is -1).
*/
extern uintN
js_GetEnterBlockStackDefs(JSContext *cx, JSScript *script, jsbytecode *pc);
#ifdef __cplusplus /* Aargh, libgjs, bug 492720. */
static JS_INLINE uintN
js_GetStackUses(const JSCodeSpec *cs, JSOp op, jsbytecode *pc)
{
JS_ASSERT(cs == &js_CodeSpec[op]);
if (cs->nuses >= 0)
return cs->nuses;
return js_GetVariableStackUses(op, pc);
}
static JS_INLINE uintN
js_GetStackDefs(JSContext *cx, const JSCodeSpec *cs, JSOp op, JSScript *script,
jsbytecode *pc)
{
JS_ASSERT(cs == &js_CodeSpec[op]);
if (cs->ndefs >= 0)
return cs->ndefs;
/* Only JSOP_ENTERBLOCK has a variable number of stack defs. */
JS_ASSERT(op == JSOP_ENTERBLOCK);
return js_GetEnterBlockStackDefs(cx, script, pc);
}
#endif
#ifdef DEBUG
/*
* Disassemblers, for debugging only.
*/
#include <stdio.h>
extern JS_FRIEND_API(JSBool)
js_Disassemble(JSContext *cx, JSScript *script, JSBool lines, FILE *fp);
extern JS_FRIEND_API(uintN)
js_Disassemble1(JSContext *cx, JSScript *script, jsbytecode *pc, uintN loc,
JSBool lines, FILE *fp);
#endif /* DEBUG */
/*
* Decompilers, for script, function, and expression pretty-printing.
*/
extern JSBool
js_DecompileScript(JSPrinter *jp, JSScript *script);
extern JSBool
js_DecompileFunctionBody(JSPrinter *jp);
extern JSBool
js_DecompileFunction(JSPrinter *jp);
/*
* Some C++ compilers treat the language linkage (extern "C" vs.
* extern "C++") as part of function (and thus pointer-to-function)
* types. The use of this typedef (defined in "C") ensures that
* js_DecompileToString's definition (in "C++") gets matched up with
* this declaration.
*/
typedef JSBool (* JSDecompilerPtr)(JSPrinter *);
extern JSString *
js_DecompileToString(JSContext *cx, const char *name, JSFunction *fun,
uintN indent, JSBool pretty, JSBool grouped, JSBool strict,
JSDecompilerPtr decompiler);
/*
* Find the source expression that resulted in v, and return a newly allocated
* C-string containing it. Fall back on v's string conversion (fallback) if we
* can't find the bytecode that generated and pushed v on the operand stack.
*
* Search the current stack frame if spindex is JSDVG_SEARCH_STACK. Don't
* look for v on the stack if spindex is JSDVG_IGNORE_STACK. Otherwise,
* spindex is the negative index of v, measured from cx->fp->sp, or from a
* lower frame's sp if cx->fp is native.
*
* The caller must call JS_free on the result after a succsesful call.
*/
extern char *
js_DecompileValueGenerator(JSContext *cx, intN spindex, jsval v,
JSString *fallback);
#define JSDVG_IGNORE_STACK 0
#define JSDVG_SEARCH_STACK 1
/*
* Given bytecode address pc in script's main program code, return the operand
* stack depth just before (JSOp) *pc executes.
*/
extern uintN
js_ReconstructStackDepth(JSContext *cx, JSScript *script, jsbytecode *pc);
JS_END_EXTERN_C
#endif /* jsopcode_h___ */
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