зеркало из https://github.com/mozilla/gecko-dev.git
Bug 704369: Move statements emit. (r=Waldo)
This commit is contained in:
Chris Leary
Родитель
8102948ce5
Коммит
1a632dd531
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@ -6107,10 +6107,165 @@ EmitReturn(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
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return true;
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}
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static bool
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EmitStatementList(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn, ptrdiff_t top)
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{
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JS_ASSERT(pn->isArity(PN_LIST));
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ptrdiff_t noteIndex = -1;
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ptrdiff_t tmp = bce->offset();
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if (pn->pn_xflags & PNX_NEEDBRACES) {
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noteIndex = NewSrcNote2(cx, bce, SRC_BRACE, 0);
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if (noteIndex < 0 || Emit1(cx, bce, JSOP_NOP) < 0)
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return JS_FALSE;
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}
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StmtInfo stmtInfo;
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PushStatement(bce, &stmtInfo, STMT_BLOCK, top);
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ParseNode *pnchild = pn->pn_head;
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if (pn->pn_xflags & PNX_FUNCDEFS) {
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/*
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* This block contains top-level function definitions. To ensure
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* that we emit the bytecode defining them before the rest of code
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* in the block we use a separate pass over functions. During the
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* main pass later the emitter will add JSOP_NOP with source notes
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* for the function to preserve the original functions position
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* when decompiling.
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*
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* Currently this is used only for functions, as compile-as-we go
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* mode for scripts does not allow separate emitter passes.
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*/
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JS_ASSERT(bce->inFunction());
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if (pn->pn_xflags & PNX_DESTRUCT) {
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/*
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* Assign the destructuring arguments before defining any
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* functions, see bug 419662.
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*/
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JS_ASSERT(pnchild->isKind(PNK_SEMI));
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JS_ASSERT(pnchild->pn_kid->isKind(PNK_VAR) || pnchild->pn_kid->isKind(PNK_CONST));
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if (!EmitTree(cx, bce, pnchild))
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return JS_FALSE;
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pnchild = pnchild->pn_next;
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}
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for (ParseNode *pn2 = pnchild; pn2; pn2 = pn2->pn_next) {
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if (pn2->isKind(PNK_FUNCTION)) {
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if (pn2->isOp(JSOP_NOP)) {
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if (!EmitTree(cx, bce, pn2))
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return JS_FALSE;
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} else {
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/*
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* JSOP_DEFFUN in a top-level block with function
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* definitions appears, for example, when "if (true)"
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* is optimized away from "if (true) function x() {}".
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* See bug 428424.
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*/
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JS_ASSERT(pn2->isOp(JSOP_DEFFUN));
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}
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}
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}
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}
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for (ParseNode *pn2 = pnchild; pn2; pn2 = pn2->pn_next) {
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if (!EmitTree(cx, bce, pn2))
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return JS_FALSE;
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}
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if (noteIndex >= 0 && !SetSrcNoteOffset(cx, bce, (uintN)noteIndex, 0, bce->offset() - tmp))
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return JS_FALSE;
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return PopStatementBCE(cx, bce);
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}
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static bool
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EmitStatement(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
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{
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JS_ASSERT(pn->isKind(PNK_SEMI));
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ParseNode *pn2 = pn->pn_kid;
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if (pn2) {
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/*
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* Top-level or called-from-a-native JS_Execute/EvaluateScript,
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* debugger, and eval frames may need the value of the ultimate
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* expression statement as the script's result, despite the fact
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* that it appears useless to the compiler.
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*
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* API users may also set the JSOPTION_NO_SCRIPT_RVAL option when
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* calling JS_Compile* to suppress JSOP_POPV.
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*/
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JSBool wantval;
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JSBool useful = wantval = !(bce->flags & (TCF_IN_FUNCTION | TCF_NO_SCRIPT_RVAL));
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/* Don't eliminate expressions with side effects. */
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if (!useful) {
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if (!CheckSideEffects(cx, bce, pn2, &useful))
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return JS_FALSE;
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}
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/*
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* Don't eliminate apparently useless expressions if they are
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* labeled expression statements. The tc->topStmt->update test
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* catches the case where we are nesting in EmitTree for a labeled
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* compound statement.
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*/
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if (!useful &&
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bce->topStmt &&
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bce->topStmt->type == STMT_LABEL &&
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bce->topStmt->update >= bce->offset()) {
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useful = true;
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}
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if (!useful) {
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/* Don't complain about directive prologue members; just don't emit their code. */
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if (!pn->isDirectivePrologueMember()) {
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bce->current->currentLine = pn2->pn_pos.begin.lineno;
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if (!ReportCompileErrorNumber(cx, bce->tokenStream(), pn2,
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JSREPORT_WARNING | JSREPORT_STRICT,
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JSMSG_USELESS_EXPR)) {
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return JS_FALSE;
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}
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}
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} else {
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JSOp op = wantval ? JSOP_POPV : JSOP_POP;
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JS_ASSERT_IF(pn2->isKind(PNK_ASSIGN), pn2->isOp(JSOP_NOP));
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#if JS_HAS_DESTRUCTURING
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if (!wantval &&
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pn2->isKind(PNK_ASSIGN) &&
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!MaybeEmitGroupAssignment(cx, bce, op, pn2, &op)) {
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return JS_FALSE;
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}
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#endif
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if (op != JSOP_NOP) {
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/*
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* Specialize JSOP_SETPROP to JSOP_SETMETHOD to defer or
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* avoid null closure cloning. Do this only for assignment
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* statements that are not completion values wanted by a
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* script evaluator, to ensure that the joined function
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* can't escape directly.
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*/
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if (!wantval &&
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pn2->isKind(PNK_ASSIGN) &&
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pn2->pn_left->isOp(JSOP_SETPROP) &&
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pn2->pn_right->isOp(JSOP_LAMBDA) &&
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pn2->pn_right->pn_funbox->joinable()) {
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if (!SetMethodFunction(cx, pn2->pn_right->pn_funbox, pn2->pn_left->pn_atom))
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return JS_FALSE;
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pn2->pn_left->setOp(JSOP_SETMETHOD);
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}
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if (!EmitTree(cx, bce, pn2))
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return JS_FALSE;
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if (Emit1(cx, bce, op) < 0)
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return JS_FALSE;
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}
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}
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}
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return true;
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}
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JSBool
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frontend::EmitTree(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
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{
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JSBool useful, wantval;
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JSBool useful;
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StmtInfo stmtInfo;
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ptrdiff_t top, off, tmp, beq, jmp;
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ParseNode *pn2, *pn3;
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@ -6242,73 +6397,8 @@ frontend::EmitTree(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
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#endif
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case PNK_STATEMENTLIST:
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{
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JS_ASSERT(pn->isArity(PN_LIST));
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noteIndex = -1;
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tmp = bce->offset();
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if (pn->pn_xflags & PNX_NEEDBRACES) {
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noteIndex = NewSrcNote2(cx, bce, SRC_BRACE, 0);
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if (noteIndex < 0 || Emit1(cx, bce, JSOP_NOP) < 0)
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return JS_FALSE;
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}
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PushStatement(bce, &stmtInfo, STMT_BLOCK, top);
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ParseNode *pnchild = pn->pn_head;
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if (pn->pn_xflags & PNX_FUNCDEFS) {
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/*
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* This block contains top-level function definitions. To ensure
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* that we emit the bytecode defining them before the rest of code
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* in the block we use a separate pass over functions. During the
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* main pass later the emitter will add JSOP_NOP with source notes
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* for the function to preserve the original functions position
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* when decompiling.
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*
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* Currently this is used only for functions, as compile-as-we go
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* mode for scripts does not allow separate emitter passes.
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*/
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JS_ASSERT(bce->inFunction());
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if (pn->pn_xflags & PNX_DESTRUCT) {
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/*
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* Assign the destructuring arguments before defining any
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* functions, see bug 419662.
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*/
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JS_ASSERT(pnchild->isKind(PNK_SEMI));
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JS_ASSERT(pnchild->pn_kid->isKind(PNK_VAR) || pnchild->pn_kid->isKind(PNK_CONST));
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if (!EmitTree(cx, bce, pnchild))
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return JS_FALSE;
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pnchild = pnchild->pn_next;
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}
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for (pn2 = pnchild; pn2; pn2 = pn2->pn_next) {
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if (pn2->isKind(PNK_FUNCTION)) {
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if (pn2->isOp(JSOP_NOP)) {
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if (!EmitTree(cx, bce, pn2))
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return JS_FALSE;
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} else {
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/*
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* JSOP_DEFFUN in a top-level block with function
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* definitions appears, for example, when "if (true)"
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* is optimized away from "if (true) function x() {}".
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* See bug 428424.
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*/
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JS_ASSERT(pn2->isOp(JSOP_DEFFUN));
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}
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}
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}
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}
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for (pn2 = pnchild; pn2; pn2 = pn2->pn_next) {
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if (!EmitTree(cx, bce, pn2))
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return JS_FALSE;
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}
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if (noteIndex >= 0 && !SetSrcNoteOffset(cx, bce, (uintN)noteIndex, 0, bce->offset() - tmp))
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return JS_FALSE;
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ok = PopStatementBCE(cx, bce);
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ok = EmitStatementList(cx, bce, pn, top);
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break;
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}
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case PNK_SEQ:
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JS_ASSERT(pn->isArity(PN_LIST));
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@ -6321,82 +6411,7 @@ frontend::EmitTree(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
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break;
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case PNK_SEMI:
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pn2 = pn->pn_kid;
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if (pn2) {
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/*
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* Top-level or called-from-a-native JS_Execute/EvaluateScript,
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* debugger, and eval frames may need the value of the ultimate
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* expression statement as the script's result, despite the fact
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* that it appears useless to the compiler.
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*
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* API users may also set the JSOPTION_NO_SCRIPT_RVAL option when
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* calling JS_Compile* to suppress JSOP_POPV.
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*/
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useful = wantval = !(bce->flags & (TCF_IN_FUNCTION | TCF_NO_SCRIPT_RVAL));
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/* Don't eliminate expressions with side effects. */
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if (!useful) {
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if (!CheckSideEffects(cx, bce, pn2, &useful))
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return JS_FALSE;
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}
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/*
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* Don't eliminate apparently useless expressions if they are
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* labeled expression statements. The tc->topStmt->update test
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* catches the case where we are nesting in EmitTree for a labeled
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* compound statement.
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*/
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if (!useful &&
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bce->topStmt &&
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bce->topStmt->type == STMT_LABEL &&
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bce->topStmt->update >= bce->offset()) {
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useful = true;
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}
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if (!useful) {
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/* Don't complain about directive prologue members; just don't emit their code. */
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if (!pn->isDirectivePrologueMember()) {
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bce->current->currentLine = pn2->pn_pos.begin.lineno;
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if (!ReportCompileErrorNumber(cx, bce->tokenStream(), pn2,
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JSREPORT_WARNING | JSREPORT_STRICT,
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JSMSG_USELESS_EXPR)) {
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return JS_FALSE;
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}
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}
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} else {
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op = wantval ? JSOP_POPV : JSOP_POP;
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JS_ASSERT_IF(pn2->isKind(PNK_ASSIGN), pn2->isOp(JSOP_NOP));
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#if JS_HAS_DESTRUCTURING
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if (!wantval &&
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pn2->isKind(PNK_ASSIGN) &&
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!MaybeEmitGroupAssignment(cx, bce, op, pn2, &op)) {
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return JS_FALSE;
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}
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#endif
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if (op != JSOP_NOP) {
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/*
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* Specialize JSOP_SETPROP to JSOP_SETMETHOD to defer or
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* avoid null closure cloning. Do this only for assignment
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* statements that are not completion values wanted by a
|
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* script evaluator, to ensure that the joined function
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* can't escape directly.
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*/
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if (!wantval &&
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pn2->isKind(PNK_ASSIGN) &&
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pn2->pn_left->isOp(JSOP_SETPROP) &&
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pn2->pn_right->isOp(JSOP_LAMBDA) &&
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pn2->pn_right->pn_funbox->joinable()) {
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if (!SetMethodFunction(cx, pn2->pn_right->pn_funbox, pn2->pn_left->pn_atom))
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return JS_FALSE;
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pn2->pn_left->setOp(JSOP_SETMETHOD);
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}
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if (!EmitTree(cx, bce, pn2))
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return JS_FALSE;
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if (Emit1(cx, bce, op) < 0)
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return JS_FALSE;
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}
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}
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}
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ok = EmitStatement(cx, bce, pn);
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break;
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case PNK_COLON:
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