From 449ea84dcc7dffb2f042fc414eb7238ae842d596 Mon Sep 17 00:00:00 2001 From: Gaming4JC Date: Sun, 14 Jul 2019 19:04:34 -0400 Subject: 1344477 - Part 1: Add JSOP_CALL_IGNORES_RV for function call that ignores return value. --- js/src/frontend/BytecodeEmitter.cpp | 64 ++++++++++++++++++++++--------------- js/src/frontend/BytecodeEmitter.h | 19 ++++++++--- 2 files changed, 53 insertions(+), 30 deletions(-) (limited to 'js/src/frontend') diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp index 7582e8df1..c2eae4344 100644 --- a/js/src/frontend/BytecodeEmitter.cpp +++ b/js/src/frontend/BytecodeEmitter.cpp @@ -4603,7 +4603,7 @@ BytecodeEmitter::emitSwitch(ParseNode* pn) // If the expression is a literal, suppress line number emission so // that debugging works more naturally. if (caseValue) { - if (!emitTree(caseValue, + if (!emitTree(caseValue, ValueUsage::WantValue, caseValue->isLiteral() ? SUPPRESS_LINENOTE : EMIT_LINENOTE)) { return false; @@ -6652,7 +6652,7 @@ BytecodeEmitter::emitLexicalScopeBody(ParseNode* body, EmitLineNumberNote emitLi } // Line notes were updated by emitLexicalScope. - return emitTree(body, emitLineNote); + return emitTree(body, ValueUsage::WantValue, emitLineNote); } // Using MOZ_NEVER_INLINE in here is a workaround for llvm.org/pr14047. See @@ -6754,9 +6754,9 @@ BytecodeEmitter::emitRequireObjectCoercible() return false; if (!emit2(JSOP_PICK, 2)) // VAL REQUIREOBJECTCOERCIBLE UNDEFINED VAL return false; - if (!emitCall(JSOP_CALL, 1)) // VAL IGNORED + if (!emitCall(JSOP_CALL_IGNORES_RV, 1))// VAL IGNORED return false; - checkTypeSet(JSOP_CALL); + checkTypeSet(JSOP_CALL_IGNORES_RV); if (!emit1(JSOP_POP)) // VAL return false; @@ -7276,12 +7276,14 @@ BytecodeEmitter::emitCStyleFor(ParseNode* pn, EmitterScope* headLexicalEmitterSc // scope, but we still need to emit code for the initializers.) if (!updateSourceCoordNotes(init->pn_pos.begin)) return false; - if (!emitTree(init)) - return false; - - if (!init->isForLoopDeclaration()) { + if (init->isForLoopDeclaration()) { + if (!emitTree(init)) + return false; + } else { // 'init' is an expression, not a declaration. emitTree left its // value on the stack. + if (!emitTree(init, ValueUsage::IgnoreValue)) + return false; if (!emit1(JSOP_POP)) return false; } @@ -7363,7 +7365,7 @@ BytecodeEmitter::emitCStyleFor(ParseNode* pn, EmitterScope* headLexicalEmitterSc if (!updateSourceCoordNotes(update->pn_pos.begin)) return false; - if (!emitTree(update)) + if (!emitTree(update, ValueUsage::IgnoreValue)) return false; if (!emit1(JSOP_POP)) return false; @@ -8690,8 +8692,9 @@ BytecodeEmitter::emitStatement(ParseNode* pn) if (useful) { JSOp op = wantval ? JSOP_SETRVAL : JSOP_POP; + ValueUsage valueUsage = wantval ? ValueUsage::WantValue : ValueUsage::IgnoreValue; MOZ_ASSERT_IF(pn2->isKind(PNK_ASSIGN), pn2->isOp(JSOP_NOP)); - if (!emitTree(pn2)) + if (!emitTree(pn2, valueUsage)) return false; if (!emit1(op)) return false; @@ -9041,7 +9044,7 @@ BytecodeEmitter::emitOptimizeSpread(ParseNode* arg0, JumpList* jmp, bool* emitte } bool -BytecodeEmitter::emitCallOrNew(ParseNode* pn) +BytecodeEmitter::emitCallOrNew(ParseNode* pn, ValueUsage valueUsage /* = ValueUsage::WantValue */) { bool callop = pn->isKind(PNK_CALL) || pn->isKind(PNK_TAGGED_TEMPLATE); /* @@ -9220,13 +9223,20 @@ BytecodeEmitter::emitCallOrNew(ParseNode* pn) } if (!spread) { - if (!emitCall(pn->getOp(), argc, pn)) - return false; + if (pn->getOp() == JSOP_CALL && valueUsage == ValueUsage::IgnoreValue) { + if (!emitCall(JSOP_CALL_IGNORES_RV, argc, pn)) + return false; + checkTypeSet(JSOP_CALL_IGNORES_RV); + } else { + if (!emitCall(pn->getOp(), argc, pn)) + return false; + checkTypeSet(pn->getOp()); + } } else { if (!emit1(pn->getOp())) return false; + checkTypeSet(pn->getOp()); } - checkTypeSet(pn->getOp()); if (pn->isOp(JSOP_EVAL) || pn->isOp(JSOP_STRICTEVAL) || pn->isOp(JSOP_SPREADEVAL) || @@ -9324,12 +9334,13 @@ BytecodeEmitter::emitLogical(ParseNode* pn) } bool -BytecodeEmitter::emitSequenceExpr(ParseNode* pn) +BytecodeEmitter::emitSequenceExpr(ParseNode* pn, + ValueUsage valueUsage /* = ValueUsage::WantValue */) { for (ParseNode* child = pn->pn_head; ; child = child->pn_next) { if (!updateSourceCoordNotes(child->pn_pos.begin)) return false; - if (!emitTree(child)) + if (!emitTree(child, child->pn_next ? ValueUsage::IgnoreValue : valueUsage)) return false; if (!child->pn_next) break; @@ -9392,7 +9403,8 @@ BytecodeEmitter::emitLabeledStatement(const LabeledStatement* pn) } bool -BytecodeEmitter::emitConditionalExpression(ConditionalExpression& conditional) +BytecodeEmitter::emitConditionalExpression(ConditionalExpression& conditional, + ValueUsage valueUsage /* = ValueUsage::WantValue */) { /* Emit the condition, then branch if false to the else part. */ if (!emitTree(&conditional.condition())) @@ -9402,13 +9414,13 @@ BytecodeEmitter::emitConditionalExpression(ConditionalExpression& conditional) if (!ifThenElse.emitCond()) return false; - if (!emitTreeInBranch(&conditional.thenExpression())) + if (!emitTreeInBranch(&conditional.thenExpression(), valueUsage)) return false; if (!ifThenElse.emitElse()) return false; - if (!emitTreeInBranch(&conditional.elseExpression())) + if (!emitTreeInBranch(&conditional.elseExpression(), valueUsage)) return false; if (!ifThenElse.emitEnd()) @@ -10288,7 +10300,8 @@ BytecodeEmitter::emitClass(ParseNode* pn) } bool -BytecodeEmitter::emitTree(ParseNode* pn, EmitLineNumberNote emitLineNote) +BytecodeEmitter::emitTree(ParseNode* pn, ValueUsage valueUsage /* = ValueUsage::WantValue */, + EmitLineNumberNote emitLineNote /* = EMIT_LINENOTE */) { JS_CHECK_RECURSION(cx, return false); @@ -10410,7 +10423,7 @@ BytecodeEmitter::emitTree(ParseNode* pn, EmitLineNumberNote emitLineNote) break; case PNK_COMMA: - if (!emitSequenceExpr(pn)) + if (!emitSequenceExpr(pn, valueUsage)) return false; break; @@ -10432,7 +10445,7 @@ BytecodeEmitter::emitTree(ParseNode* pn, EmitLineNumberNote emitLineNote) break; case PNK_CONDITIONAL: - if (!emitConditionalExpression(pn->as())) + if (!emitConditionalExpression(pn->as(), valueUsage)) return false; break; @@ -10545,7 +10558,7 @@ BytecodeEmitter::emitTree(ParseNode* pn, EmitLineNumberNote emitLineNote) case PNK_CALL: case PNK_GENEXP: case PNK_SUPERCALL: - if (!emitCallOrNew(pn)) + if (!emitCallOrNew(pn, valueUsage)) return false; break; @@ -10703,12 +10716,13 @@ BytecodeEmitter::emitTree(ParseNode* pn, EmitLineNumberNote emitLineNote) } bool -BytecodeEmitter::emitTreeInBranch(ParseNode* pn) +BytecodeEmitter::emitTreeInBranch(ParseNode* pn, + ValueUsage valueUsage /* = ValueUsage::WantValue */) { // Code that may be conditionally executed always need their own TDZ // cache. TDZCheckCache tdzCache(this); - return emitTree(pn); + return emitTree(pn, valueUsage); } static bool diff --git a/js/src/frontend/BytecodeEmitter.h b/js/src/frontend/BytecodeEmitter.h index 4e5209593..99d6a2ff7 100644 --- a/js/src/frontend/BytecodeEmitter.h +++ b/js/src/frontend/BytecodeEmitter.h @@ -171,6 +171,11 @@ struct JumpList { void patchAll(jsbytecode* code, JumpTarget target); }; +enum class ValueUsage { + WantValue, + IgnoreValue +}; + struct MOZ_STACK_CLASS BytecodeEmitter { class TDZCheckCache; @@ -434,10 +439,12 @@ struct MOZ_STACK_CLASS BytecodeEmitter }; // Emit code for the tree rooted at pn. - MOZ_MUST_USE bool emitTree(ParseNode* pn, EmitLineNumberNote emitLineNote = EMIT_LINENOTE); + MOZ_MUST_USE bool emitTree(ParseNode* pn, ValueUsage valueUsage = ValueUsage::WantValue, + EmitLineNumberNote emitLineNote = EMIT_LINENOTE); // Emit code for the tree rooted at pn with its own TDZ cache. - MOZ_MUST_USE bool emitTreeInBranch(ParseNode* pn); + MOZ_MUST_USE bool emitTreeInBranch(ParseNode* pn, + ValueUsage valueUsage = ValueUsage::WantValue); // Emit global, eval, or module code for tree rooted at body. Always // encompasses the entire source. @@ -724,16 +731,18 @@ struct MOZ_STACK_CLASS BytecodeEmitter MOZ_MUST_USE bool emitRightAssociative(ParseNode* pn); MOZ_MUST_USE bool emitLeftAssociative(ParseNode* pn); MOZ_MUST_USE bool emitLogical(ParseNode* pn); - MOZ_MUST_USE bool emitSequenceExpr(ParseNode* pn); + MOZ_MUST_USE bool emitSequenceExpr(ParseNode* pn, + ValueUsage valueUsage = ValueUsage::WantValue); MOZ_NEVER_INLINE MOZ_MUST_USE bool emitIncOrDec(ParseNode* pn); - MOZ_MUST_USE bool emitConditionalExpression(ConditionalExpression& conditional); + MOZ_MUST_USE bool emitConditionalExpression(ConditionalExpression& conditional, + ValueUsage valueUsage = ValueUsage::WantValue); MOZ_MUST_USE bool isRestParameter(ParseNode* pn, bool* result); MOZ_MUST_USE bool emitOptimizeSpread(ParseNode* arg0, JumpList* jmp, bool* emitted); - MOZ_MUST_USE bool emitCallOrNew(ParseNode* pn); + MOZ_MUST_USE bool emitCallOrNew(ParseNode* pn, ValueUsage valueUsage = ValueUsage::WantValue); MOZ_MUST_USE bool emitSelfHostedCallFunction(ParseNode* pn); MOZ_MUST_USE bool emitSelfHostedResumeGenerator(ParseNode* pn); MOZ_MUST_USE bool emitSelfHostedForceInterpreter(ParseNode* pn); -- cgit v1.2.3