/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * * The contents of this file are subject to the Netscape Public License * Version 1.0 (the "NPL"); you may not use this file except in * compliance with the NPL. You may obtain a copy of the NPL at * http://www.mozilla.org/NPL/ * * Software distributed under the NPL is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL * for the specific language governing rights and limitations under the * NPL. * * The Initial Developer of this code under the NPL is Netscape * Communications Corporation. Portions created by Netscape are * Copyright (C) 1998 Netscape Communications Corporation. All Rights * Reserved. */ #ifndef jsemit_h___ #define jsemit_h___ /* * JS bytecode generation. */ #include #include "prtypes.h" #include "jsatom.h" #include "jsopcode.h" #include "jsprvtd.h" #include "jspubtd.h" PR_BEGIN_EXTERN_C typedef enum JSStmtType { STMT_BLOCK = 0, /* compound statement: { s1[;... sN] } */ STMT_LABEL = 1, /* labeled statement: l: s */ STMT_IF = 2, /* if (then) statement */ STMT_ELSE = 3, /* else statement */ STMT_SWITCH = 4, /* switch statement */ STMT_WITH = 5, /* with statement */ STMT_TRY = 6, /* try statement */ STMT_CATCH = 7, /* catch block */ STMT_FINALLY = 8, /* finally statement */ STMT_DO_LOOP = 9, /* do/while loop statement */ STMT_FOR_LOOP = 10, /* for loop statement */ STMT_FOR_IN_LOOP = 11, /* for/in loop statement */ STMT_WHILE_LOOP = 12 /* while loop statement */ } JSStmtType; #define STMT_IS_LOOP(stmt) ((stmt)->type >= STMT_DO_LOOP) typedef struct JSStmtInfo JSStmtInfo; struct JSStmtInfo { JSStmtType type; /* statement type */ ptrdiff_t top; /* offset of loop top from cg base */ ptrdiff_t update; /* loop update offset (top if none) */ ptrdiff_t breaks; /* offset of last break in loop */ ptrdiff_t continues; /* offset of last continue in loop */ JSAtom *label; /* label name if type is STMT_LABEL */ JSStmtInfo *down; /* info for enclosing statement */ }; #define SET_STATEMENT_TOP(stmt, top) \ ((stmt)->top = (stmt)->update = (stmt)->breaks = (stmt)->continues = (top)) struct JSTreeContext { /* tree context for semantic checks */ uint32 flags; /* statement state flags, see below */ uint32 tryCount; /* total count of try statements parsed */ JSStmtInfo *topStmt; /* top of statement info stack */ }; #define TCF_IN_FUNCTION 0x01 /* parsing inside function body */ #define TCF_RETURN_EXPR 0x02 /* function has 'return expr;' */ #define TCF_RETURN_VOID 0x04 /* function has 'return;' */ #define INIT_TREE_CONTEXT(tc) \ ((tc)->flags = 0, (tc)->tryCount = 0, (tc)->topStmt = NULL) struct JSCodeGenerator { void *codeMark; /* low watermark in cx->codePool */ void *tempMark; /* low watermark in cx->tempPool */ jsbytecode *base; /* base of JS bytecode vector */ jsbytecode *limit; /* one byte beyond end of bytecode */ jsbytecode *next; /* pointer to next free bytecode */ JSAtomList atomList; /* literals indexed for mapping */ ptrdiff_t lastCodeOffset; /* offset of last non-nop opcode */ intN stackDepth; /* current stack depth in basic block */ uintN maxStackDepth; /* maximum stack depth so far */ jssrcnote *notes; /* source notes, see below */ uintN noteCount; /* number of source notes so far */ ptrdiff_t lastNoteOffset; /* code offset for last source note */ const char *filename; /* null or weak link to source filename */ uintN firstLine; /* first line, for js_NewScriptFromCG */ uintN currentLine; /* line number for tree-based srcnote gen */ JSPrincipals *principals; /* principals for constant folding eval */ JSTreeContext treeContext; /* for break/continue code generation */ JSTryNote *tryBase; /* first exception handling block */ JSTryNote *tryNext; /* next avail block */ JSTryNote *tryLimit; /* pointer to one-past-end block */ }; #define CG_CODE(cg,offset) ((cg)->base + (offset)) #define CG_OFFSET(cg) ((cg)->next - (cg)->base) #define CG_RESET(cg) ((cg)->next = (cg)->base, \ ATOM_LIST_INIT(&(cg)->atomList), \ (cg)->lastCodeOffset = 0, \ (cg)->stackDepth = (cg)->maxStackDepth = 0, \ (cg)->currentLine = (cg)->firstLine, \ INIT_TREE_CONTEXT(&(cg)->treeContext), \ (cg)->tryNext = (cg)->tryBase, \ CG_RESET_NOTES(cg)) #define CG_RESET_NOTES(cg) ((cg)->notes = NULL, (cg)->noteCount = 0, \ (cg)->lastNoteOffset = 0) #define CG_PUSH(cg, newcg) ((newcg)->atomList = (cg)->atomList) #define CG_POP(cg, newcg) ((cg)->atomList = (newcg)->atomList) /* * Initialize cg to allocate bytecode space from cx->codePool, and srcnote * space from cx->tempPool. Return true on success. Report an error and * return false if the initial code segment can't be allocated. */ extern JS_FRIEND_API(JSBool) js_InitCodeGenerator(JSContext *cx, JSCodeGenerator *cg, const char *filename, uintN lineno, JSPrincipals *principals); /* * Release cx->codePool and cx->tempPool to marks set by js_InitCodeGenerator. */ extern JS_FRIEND_API(void) js_ResetCodeGenerator(JSContext *cx, JSCodeGenerator *cg); /* * Emit one bytecode. */ extern ptrdiff_t js_Emit1(JSContext *cx, JSCodeGenerator *cg, JSOp op); /* * Emit two bytecodes, an opcode (op) with a byte of immediate operand (op1). */ extern ptrdiff_t js_Emit2(JSContext *cx, JSCodeGenerator *cg, JSOp op, jsbytecode op1); /* * Emit three bytecodes, an opcode with two bytes of immediate operands. */ extern ptrdiff_t js_Emit3(JSContext *cx, JSCodeGenerator *cg, JSOp op, jsbytecode op1, jsbytecode op2); /* * Emit (1 + extra) bytecodes, for N bytes of op and its immediate operand. */ extern ptrdiff_t js_EmitN(JSContext *cx, JSCodeGenerator *cg, JSOp op, size_t extra); /* * Unsafe macro to call js_SetJumpOffset and return false if it does. */ #define CHECK_AND_SET_JUMP_OFFSET(cx,cg,pc,off) \ PR_BEGIN_MACRO \ if (!js_SetJumpOffset(cx, cg, pc, off)) \ return JS_FALSE; \ PR_END_MACRO #define CHECK_AND_SET_JUMP_OFFSET_AT(cx,cg,off) \ CHECK_AND_SET_JUMP_OFFSET(cx, cg, CG_CODE(cg,off), CG_OFFSET(cg) - (off)) extern JSBool js_SetJumpOffset(JSContext *cx, JSCodeGenerator *cg, jsbytecode *pc, ptrdiff_t off); /* * Push the C-stack-allocated struct at stmt onto the stmtInfo stack. */ extern void js_PushStatement(JSTreeContext *tc, JSStmtInfo *stmt, JSStmtType type, ptrdiff_t top); /* * Emit a break instruction, recording it for backpatching. */ extern ptrdiff_t js_EmitBreak(JSContext *cx, JSCodeGenerator *cg, JSStmtInfo *stmt, JSAtomListElement *label); /* * Emit a continue instruction, recording it for backpatching. */ extern ptrdiff_t js_EmitContinue(JSContext *cx, JSCodeGenerator *cg, JSStmtInfo *stmt, JSAtomListElement *label); /* * Pop tc->topStmt. If the top JSStmtInfo struct is not stack-allocated, it * is up to the caller to free it. */ extern void js_PopStatement(JSTreeContext *tc); /* * Like js_PopStatement(&cg->treeContext), also patch breaks and continues. * May fail if a jump offset overflows. */ extern JSBool js_PopStatementCG(JSContext *cx, JSCodeGenerator *cg); /* * Emit code into cg for the tree rooted at pn. */ extern JSBool js_EmitTree(JSContext *cx, JSCodeGenerator *cg, JSParseNode *pn); /* * Emit code into cg for the tree rooted at body, then create a persistent * script for fun from cg. */ extern JSBool js_EmitFunctionBody(JSContext *cx, JSCodeGenerator *cg, JSParseNode *body, JSFunction *fun); /* * Source notes generated along with bytecode for decompiling and debugging. * A source note is a uint8 with 5 bits of type and 3 of offset from the pc of * the previous note. If 3 bits of offset aren't enough, extended delta notes * (SRC_XDELTA) consisting of 2 set high order bits followed by 6 offset bits * are emitted before the next note. Some notes have operand offsets encoded * in note bytes or byte-pairs. * * At most one "gettable" note (i.e., a note of type other than SRC_NEWLINE, * SRC_SETLINE, and SRC_XDELTA) applies to a given bytecode. * * NB: the js_SrcNoteName and js_SrcNoteArity arrays in jsemit.c are indexed * by this enum, so their initializers need to match the order here. */ typedef enum JSSrcNoteType { SRC_NULL = 0, /* terminates a note vector */ SRC_IF = 1, /* JSOP_IFEQ bytecode is from an if-then */ SRC_IF_ELSE = 2, /* JSOP_IFEQ bytecode is from an if-then-else */ SRC_WHILE = 3, /* JSOP_IFEQ is from a while loop */ SRC_FOR = 4, /* JSOP_NOP or JSOP_POP in for loop head */ SRC_CONTINUE = 5, /* JSOP_GOTO is a continue, not a break */ SRC_VAR = 6, /* JSOP_NAME/FORNAME with a var declaration */ SRC_COMMA = 7, /* JSOP_POP representing a comma operator */ SRC_ASSIGNOP = 8, /* += or another assign-op follows */ SRC_COND = 9, /* JSOP_IFEQ is from conditional ?: operator */ SRC_PAREN = 10, /* JSOP_NOP generated to mark user parens */ SRC_HIDDEN = 11, /* JSOP_LEAVEWITH for break/continue in with */ SRC_PCBASE = 12, /* offset of first obj.prop.subprop bytecode */ SRC_LABEL = 13, /* JSOP_NOP for label: with atomid immediate */ SRC_LABELBRACE = 14, /* JSOP_NOP for label: {...} begin brace */ SRC_ENDBRACE = 15, /* JSOP_NOP for label: {...} end brace */ SRC_BREAK2LABEL = 16, /* JSOP_GOTO for 'break label' with atomid */ SRC_CONT2LABEL = 17, /* JSOP_GOTO for 'continue label' with atomid */ SRC_SWITCH = 18, /* JSOP_*SWITCH with offset to end of switch */ SRC_FUNCDEF = 19, /* JSOP_NOP for function f() with atomid */ SRC_TRY = 20, /* JSOP_NOP for beginning of try{} section */ SRC_CATCH = 21, /* beginning of catch block (at conditional) */ SRC_NEWLINE = 22, /* bytecode follows a source newline */ SRC_SETLINE = 23, /* a file-absolute source line number note */ SRC_XDELTA = 24 /* 24-31 are for extended delta notes */ } JSSrcNoteType; #define SN_TYPE_BITS 5 #define SN_DELTA_BITS 3 #define SN_XDELTA_BITS 6 #define SN_TYPE_MASK (PR_BITMASK(SN_TYPE_BITS) << SN_DELTA_BITS) #define SN_DELTA_MASK ((ptrdiff_t)PR_BITMASK(SN_DELTA_BITS)) #define SN_XDELTA_MASK ((ptrdiff_t)PR_BITMASK(SN_XDELTA_BITS)) #define SN_MAKE_NOTE(sn,t,d) (*(sn) = (jssrcnote) \ (((t) << SN_DELTA_BITS) \ | ((d) & SN_DELTA_MASK))) #define SN_MAKE_XDELTA(sn,d) (*(sn) = (jssrcnote) \ ((SRC_XDELTA << SN_DELTA_BITS) \ | ((d) & SN_XDELTA_MASK))) #define SN_IS_XDELTA(sn) ((*(sn) >> SN_DELTA_BITS) >= SRC_XDELTA) #define SN_TYPE(sn) (SN_IS_XDELTA(sn) ? SRC_XDELTA \ : *(sn) >> SN_DELTA_BITS) #define SN_SET_TYPE(sn,type) SN_MAKE_NOTE(sn, type, SN_DELTA(sn)) #define SN_IS_GETTABLE(sn) (SN_TYPE(sn) < SRC_NEWLINE) #define SN_DELTA(sn) ((ptrdiff_t)(SN_IS_XDELTA(sn) \ ? *(sn) & SN_XDELTA_MASK \ : *(sn) & SN_DELTA_MASK)) #define SN_SET_DELTA(sn,delta) (SN_IS_XDELTA(sn) \ ? SN_MAKE_XDELTA(sn, delta) \ : SN_MAKE_NOTE(sn, SN_TYPE(sn), delta)) #define SN_DELTA_LIMIT ((ptrdiff_t)PR_BIT(SN_DELTA_BITS)) #define SN_XDELTA_LIMIT ((ptrdiff_t)PR_BIT(SN_XDELTA_BITS)) /* * Offset fields follow certain notes and are frequency-encoded: an offset in * [0,127] consumes one byte, an offset in [128,32767] takes two, and the high * bit of the first byte is set. */ #define SN_2BYTE_OFFSET_FLAG 0x80 #define SN_2BYTE_OFFSET_MASK 0x7f extern JS_FRIEND_DATA(const char *) js_SrcNoteName[]; extern JS_FRIEND_DATA(uint8) js_SrcNoteArity[]; extern JS_FRIEND_DATA(uintN) js_SrcNoteLength(jssrcnote *sn); #define SN_LENGTH(sn) ((js_SrcNoteArity[SN_TYPE(sn)] == 0) ? 1 \ : js_SrcNoteLength(sn)) #define SN_NEXT(sn) ((sn) + SN_LENGTH(sn)) /* A source note array is terminated by an all-zero element. */ #define SN_MAKE_TERMINATOR(sn) (*(sn) = SRC_NULL) #define SN_IS_TERMINATOR(sn) (*(sn) == SRC_NULL) /* * Append a new source note of the given type (and therefore size) to cg's * notes dynamic array, updating cg->noteCount. Return the new note's index * within the array pointed at by cg->notes. Return -1 if out of memory. */ extern intN js_NewSrcNote(JSContext *cx, JSCodeGenerator *cg, JSSrcNoteType type); extern intN js_NewSrcNote2(JSContext *cx, JSCodeGenerator *cg, JSSrcNoteType type, ptrdiff_t offset); extern intN js_NewSrcNote3(JSContext *cx, JSCodeGenerator *cg, JSSrcNoteType type, ptrdiff_t offset1, ptrdiff_t offset2); /* * Get and set the offset operand identified by which (0 for the first, etc.). */ extern JS_FRIEND_API(ptrdiff_t) js_GetSrcNoteOffset(jssrcnote *sn, uintN which); extern JSBool js_SetSrcNoteOffset(JSContext *cx, JSCodeGenerator *cg, uintN index, uintN which, ptrdiff_t offset); /* * Finish taking source notes in cx's tempPool by copying them to new * stable store allocated via JS_malloc. Return null on malloc failure, * which means this function reported an error. */ extern JS_FRIEND_API(jssrcnote *) js_FinishTakingSrcNotes(JSContext *cx, JSCodeGenerator *cg); /* * Allocate cg->treeContext.tryCount notes (plus one for the end sentinel) * from cx->tempPool and set cg->tryBase/tryNext/tryLimit for exactly tryCount * js_NewTryNote calls. The storage is freed in one fell swoop by JS_Compile* * API entry points at the end of compilation. */ extern JSBool js_AllocTryNotes(JSContext *cx, JSCodeGenerator *cg); /* * Grab the next trynote slot in cg, filling it in appropriately. */ extern JS_FRIEND_API(JSTryNote *) js_NewTryNote(JSContext *cx, JSCodeGenerator *cg, ptrdiff_t start, ptrdiff_t end, ptrdiff_t catch, ptrdiff_t finally); /* * Finish generating exception information, and copy it to JS_malloc * storage. */ extern JS_FRIEND_API(JSBool) js_FinishTakingTryNotes(JSContext *cx, JSCodeGenerator *cg, JSTryNote **tryp); PR_END_EXTERN_C #endif /* jsemit_h___ */