Bug 1477621 - Part 1: Add source note field constants for switch. r=jandem (53c7a51a) · Commits · The Tor Project / Applications / Tor Browser

js/src/frontend/SourceNotes.h

+41 −5

Original line number	Diff line number	Diff line
		@@ -34,6 +34,44 @@ namespace js {
		* NB: the js_SrcNoteSpec array in BytecodeEmitter.cpp is indexed by this
		* enum, so its initializers need to match the order here.
		*/

		class SrcNote {
		public:
		// SRC_TABLESWITCH: Source note for JSOP_TABLESWITCH.
		class TableSwitch {
		public:
		enum Fields {
		// The offset of the end of switch (the first non-JumpTarget op
		// after switch) from JSOP_TABLESWITCH.
		EndOffset,
		Count
		};
		};
		// SRC_CONDSWITCH: Source note for JSOP_CONDSWITCH.
		class CondSwitch {
		public:
		enum Fields {
		// The offset of the end of switch (the first non-JumpTarget op
		// after switch) from JSOP_CONDSWITCH.
		EndOffset,

		// The offset of JSOP_CASE for the first case from JSOP_CONDSWITCH.
		FirstCaseOffset,
		Count
		};
		};
		// SRC_NEXTCASE: Source note for JSOP_CASE in a JSOP_CONDSWITCH.
		class NextCase {
		public:
		enum Fields {
		// Offset of the next JSOP_CASE from this JSOP_CASE. This field is
		// 0 if this is the last JSOP_CASE.
		NextCaseOffset,
		Count
		};
		};
		};

		#define FOR_EACH_SRC_NOTE_TYPE(M) \
		M(SRC_NULL, "null", 0) /* Terminates a note vector. */ \
		M(SRC_IF, "if", 0) /* JSOP_IFEQ bytecode is from an if-then. */ \
		@@ -50,11 +88,9 @@ namespace js {
		M(SRC_BREAK, "break", 0) /* JSOP_GOTO is a break. */ \
		M(SRC_BREAK2LABEL, "break2label", 0) /* JSOP_GOTO for 'break label'. */ \
		M(SRC_SWITCHBREAK, "switchbreak", 0) /* JSOP_GOTO is a break in a switch. */ \
		M(SRC_TABLESWITCH, "tableswitch", 1) /* JSOP_TABLESWITCH; offset points to end of switch. */ \
		M(SRC_CONDSWITCH, "condswitch", 2) /* JSOP_CONDSWITCH; 1st offset points to end of switch, \
		2nd points to first JSOP_CASE. */ \
		M(SRC_NEXTCASE, "nextcase", 1) /* Distance forward from one CASE in a CONDSWITCH to \
		the next. */ \
		M(SRC_TABLESWITCH, "tableswitch", SrcNote::TableSwitch::Count) \
		M(SRC_CONDSWITCH, "condswitch", SrcNote::CondSwitch::Count) \
		M(SRC_NEXTCASE, "nextcase", SrcNote::NextCase::Count) \
		M(SRC_ASSIGNOP, "assignop", 0) /* += or another assign-op follows. */ \
		M(SRC_CLASS_SPAN, "class", 2) /* The starting and ending offsets for the class, used \
		for toString correctness for default ctors. */ \

js/src/frontend/SwitchEmitter.cpp

+11 −2

Original line number	Diff line number	Diff line
		@@ -233,9 +233,12 @@ SwitchEmitter::emitCaseOrDefaultJump(uint32_t caseIndex, bool isDefault)
		if (state_ == State::Case) {
		// Link the last JSOP_CASE's SRC_NEXTCASE to current JSOP_CASE for the
		// benefit of IonBuilder.
		if (!bce_->setSrcNoteOffset(caseNoteIndex_, 0, bce_->offset() - lastCaseOffset_))
		if (!bce_->setSrcNoteOffset(caseNoteIndex_, SrcNote::NextCase::NextCaseOffset,
		bce_->offset() - lastCaseOffset_))
		{
		return false;
		}
		}

		if (!bce_->newSrcNote2(SRC_NEXTCASE, 0, &caseNoteIndex_))
		return false;
		@@ -392,8 +395,14 @@ SwitchEmitter::emitEnd()
		}

		// Set the SRC_SWITCH note's offset operand to tell end of switch.
		if (!bce_->setSrcNoteOffset(noteIndex_, 0, bce_->lastNonJumpTargetOffset() - top_))
		// This code is shared between table switch and cond switch.
		static_assert(unsigned(SrcNote::TableSwitch::EndOffset) == unsigned(SrcNote::CondSwitch::EndOffset),
		"{TableSwitch,CondSwitch}::EndOffset should be same");
		if (!bce_->setSrcNoteOffset(noteIndex_, SrcNote::TableSwitch::EndOffset,
		bce_->lastNonJumpTargetOffset() - top_))
		{
		return false;
		}

		if (kind_ == Kind::Table) {
		// Skip over the already-initialized switch bounds.

js/src/jit/IonControlFlow.cpp

+6 −6

Original line number	Diff line number	Diff line
		@@ -1118,8 +1118,8 @@ ControlFlowGenerator::processCondSwitch()
		MOZ_ASSERT(SN_TYPE(sn) == SRC_CONDSWITCH);

		// Get the exit pc
		jsbytecode* exitpc = pc + GetSrcNoteOffset(sn, 0);
		jsbytecode* firstCase = pc + GetSrcNoteOffset(sn, 1);
		jsbytecode* exitpc = pc + GetSrcNoteOffset(sn, SrcNote::CondSwitch::EndOffset);
		jsbytecode* firstCase = pc + GetSrcNoteOffset(sn, SrcNote::CondSwitch::FirstCaseOffset);

		// Iterate all cases in the conditional switch.
		// - Stop at the default case. (always emitted after the last case)
		@@ -1134,7 +1134,7 @@ ControlFlowGenerator::processCondSwitch()
		// Fetch the next case.
		jssrcnote* caseSn = GetSrcNote(gsn, script, curCase);
		MOZ_ASSERT(caseSn && SN_TYPE(caseSn) == SRC_NEXTCASE);
		ptrdiff_t off = GetSrcNoteOffset(caseSn, 0);
		ptrdiff_t off = GetSrcNoteOffset(caseSn, SrcNote::NextCase::NextCaseOffset);
		MOZ_ASSERT_IF(off == 0, JSOp(*GetNextPc(curCase)) == JSOP_JUMPTARGET);
		curCase = off ? curCase + off : GetNextPc(GetNextPc(curCase));
		MOZ_ASSERT(pc < curCase && curCase <= exitpc);
		@@ -1167,7 +1167,7 @@ ControlFlowGenerator::processCondSwitch()
		defaultIdx++;

		jssrcnote* caseSn = GetSrcNote(gsn, script, curCase);
		ptrdiff_t off = GetSrcNoteOffset(caseSn, 0);
		ptrdiff_t off = GetSrcNoteOffset(caseSn, SrcNote::NextCase::NextCaseOffset);
		curCase = off ? curCase + off : GetNextPc(GetNextPc(curCase));
		lastTarget = curTarget;
		}
		@@ -1223,7 +1223,7 @@ ControlFlowGenerator::processCondSwitchCase(CFGState& state)

		// Fetch the following case in which we will continue.
		jssrcnote* sn = GetSrcNote(gsn, script, pc);
		ptrdiff_t off = GetSrcNoteOffset(sn, 0);
		ptrdiff_t off = GetSrcNoteOffset(sn, SrcNote::NextCase::NextCaseOffset);
		MOZ_ASSERT_IF(off == 0, JSOp(*GetNextPc(pc)) == JSOP_JUMPTARGET);
		jsbytecode* casePc = off ? pc + off : GetNextPc(GetNextPc(pc));
		bool nextIsDefault = JSOp(*casePc) == JSOP_DEFAULT;
		@@ -1849,7 +1849,7 @@ ControlFlowGenerator::processTableSwitch(JSOp op, jssrcnote* sn)
		MOZ_ASSERT(SN_TYPE(sn) == SRC_TABLESWITCH);

		// Get the default and exit pc
		jsbytecode* exitpc = pc + GetSrcNoteOffset(sn, 0);
		jsbytecode* exitpc = pc + GetSrcNoteOffset(sn, SrcNote::TableSwitch::EndOffset);
		jsbytecode* defaultpc = pc + GET_JUMP_OFFSET(pc);

		MOZ_ASSERT(defaultpc > pc && defaultpc <= exitpc);

js/src/shell/js.cpp

+19 −4

Original line number	Diff line number	Diff line
		@@ -2757,16 +2757,26 @@ SrcNotes(JSContext* cx, HandleScript script, Sprinter* sp)
		break;

		case SRC_WHILE:
		case SRC_NEXTCASE:
		if (!sp->jsprintf(" offset %u", unsigned(GetSrcNoteOffset(sn, 0))))
		return false;
		break;

		case SRC_NEXTCASE:
		if (!sp->jsprintf(" next case offset %u",
		unsigned(GetSrcNoteOffset(sn, SrcNote::NextCase::NextCaseOffset))))
		{
		return false;
		}
		break;

		case SRC_TABLESWITCH: {
		mozilla::DebugOnly<JSOp> op = JSOp(script->code()[offset]);
		MOZ_ASSERT(op == JSOP_TABLESWITCH);
		if (!sp->jsprintf(" length %u", unsigned(GetSrcNoteOffset(sn, 0))))
		if (!sp->jsprintf(" end offset %u",
		unsigned(GetSrcNoteOffset(sn, SrcNote::TableSwitch::EndOffset))))
		{
		return false;
		}
		UpdateSwitchTableBounds(cx, script, offset,
		&switchTableStart, &switchTableEnd);
		break;
		@@ -2774,9 +2784,14 @@ SrcNotes(JSContext* cx, HandleScript script, Sprinter* sp)
		case SRC_CONDSWITCH: {
		mozilla::DebugOnly<JSOp> op = JSOp(script->code()[offset]);
		MOZ_ASSERT(op == JSOP_CONDSWITCH);
		if (!sp->jsprintf(" length %u", unsigned(GetSrcNoteOffset(sn, 0))))
		if (!sp->jsprintf(" end offset %u",
		unsigned(GetSrcNoteOffset(sn, SrcNote::CondSwitch::EndOffset))))
		{
		return false;
		if (unsigned caseOff = (unsigned) GetSrcNoteOffset(sn, 1)) {
		}
		if (unsigned caseOff =
		unsigned(GetSrcNoteOffset(sn, SrcNote::CondSwitch::FirstCaseOffset)))
		{
		if (!sp->jsprintf(" first case offset %u", caseOff))
		return false;
		}

js/src/vm/CodeCoverage.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -200,7 +200,7 @@ LCovSource::writeScript(JSScript* script)
		else if (type == SRC_NEWLINE)
		lineno++;
		else if (type == SRC_TABLESWITCH)
		tableswitchExitOffset = GetSrcNoteOffset(sn, 0);
		tableswitchExitOffset = GetSrcNoteOffset(sn, SrcNote::TableSwitch::EndOffset);

		sn = SN_NEXT(sn);
		snpc += SN_DELTA(sn);