diff options
Diffstat (limited to 'js/src/jsopcode.h')
-rw-r--r-- | js/src/jsopcode.h | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/js/src/jsopcode.h b/js/src/jsopcode.h new file mode 100644 index 0000000..68cf514 --- /dev/null +++ b/js/src/jsopcode.h @@ -0,0 +1,512 @@ +/* -*- 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" + +#ifdef __cplusplus +# include "jsvalue.h" +#endif + +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, + + /* + * These pseudo-ops help js_DecompileValueGenerator decompile JSOP_SETNAME, + * JSOP_SETPROP, and JSOP_SETELEM, respectively. They are never stored in + * bytecode, so they don't preempt valid opcodes. + */ + JSOP_GETPROP2 = JSOP_LIMIT, + JSOP_GETELEM2 = JSOP_LIMIT + 1, + JSOP_FAKE_LIMIT = JSOP_GETELEM2 +} 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_GLOBAL 21 /* uint16 global array index */ +#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 Class.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_TMPSLOT3 (3U<<22) /* interpreter uses extra 3 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 + Compiler::compileScript) */ +#define JOF_GNAME (1U<<25) /* predicted global name */ + +/* 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 */ + +#ifdef __cplusplus + uint32 type() const { return JOF_TYPE(format); } +#endif +}; + +extern const JSCodeSpec js_CodeSpec[]; +extern uintN js_NumCodeSpecs; +extern const char *js_CodeName[]; +extern const char js_EscapeMap[]; + +/* Silence unreferenced formal parameter warnings */ +#ifdef _MSC_VER +#pragma warning(push) +#pragma warning(disable:4100) +#endif + +/* + * 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 + * jsinterp.cpp. + */ +#define GET_DOUBLE_FROM_BYTECODE(script, pc, pcoff, dbl) \ + JS_BEGIN_MACRO \ + uintN index_ = js_GetIndexFromBytecode(cx, (script), (pc), (pcoff)); \ + JS_ASSERT(index_ < (script)->consts()->length); \ + (dbl) = (script)->getConst(index_).toDouble(); \ + 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 + * (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 + +#ifdef __cplusplus +namespace js { + +static inline char * +DecompileValueGenerator(JSContext *cx, intN spindex, const Value &v, + JSString *fallback) +{ + return js_DecompileValueGenerator(cx, spindex, Jsvalify(v), fallback); +} + +} +#endif + +/* + * 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); + +#ifdef _MSC_VER +#pragma warning(pop) +#endif + +JS_END_EXTERN_C + +#endif /* jsopcode_h___ */ |