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package sun.tools.tree;

import sun.tools.java.*;
import sun.tools.asm.Assembler;
import sun.tools.asm.Label;
import sun.tools.asm.SwitchData;
import java.io.PrintStream;
import java.util.Hashtable;

WARNING: The contents of this source file are not part of any supported API. Code that depends on them does so at its own risk: they are subject to change or removal without notice.
/** * WARNING: The contents of this source file are not part of any * supported API. Code that depends on them does so at its own risk: * they are subject to change or removal without notice. */
public class SwitchStatement extends Statement { Expression expr; Statement args[];
Constructor
/** * Constructor */
public SwitchStatement(long where, Expression expr, Statement args[]) { super(SWITCH, where); this.expr = expr; this.args = args; }
Check statement
/** * Check statement */
Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) { checkLabel(env, ctx); CheckContext newctx = new CheckContext(ctx, this); vset = expr.checkValue(env, newctx, reach(env, vset), exp); Type switchType = expr.type; expr = convert(env, newctx, Type.tInt, expr); Hashtable tab = new Hashtable(); boolean hasDefault = false; // Note that vs is reset to vset.copy() on every case label. // If the first substatement is not a case label, it is unreached. Vset vs = DEAD_END; for (int i = 0 ; i < args.length ; i++) { Statement s = args[i]; if (s.op == CASE) { vs = s.check(env, newctx, vs.join(vset.copy()), exp); Expression lbl = ((CaseStatement)s).expr; if (lbl != null) { if (lbl instanceof IntegerExpression) { Integer Ivalue = (Integer)(((IntegerExpression)lbl).getValue()); int ivalue = Ivalue.intValue(); if (tab.get(lbl) != null) { env.error(s.where, "duplicate.label", Ivalue); } else { tab.put(lbl, s); boolean overflow; switch (switchType.getTypeCode()) { case TC_BYTE: overflow = (ivalue != (byte)ivalue); break; case TC_SHORT: overflow = (ivalue != (short)ivalue); break; case TC_CHAR: overflow = (ivalue != (char)ivalue); break; default: overflow = false; } if (overflow) { env.error(s.where, "switch.overflow", Ivalue, switchType); } } } else { // Suppose a class got an error early on during // checking. It will set all of its members to // have the status "ERROR". Now suppose that a // case label refers to one of this class's // fields. When we check the case label, the // compiler will try to inline the FieldExpression. // Since the expression has ERROR status, it doesn't // inline. This means that instead of the case // label being an IntegerExpression, it will still // be a FieldExpression, and we will end up in this // else block. So, before we just assume that // the expression isn't constant, do a check to // see if it was constant but unable to inline. // This eliminates some spurious error messages. // (Bug id 4067498). if (!lbl.isConstant() || lbl.getType() != Type.tInt) { env.error(s.where, "const.expr.required"); } } } else { if (hasDefault) { env.error(s.where, "duplicate.default"); } hasDefault = true; } } else { vs = s.checkBlockStatement(env, newctx, vs, exp); } } if (!vs.isDeadEnd()) { newctx.vsBreak = newctx.vsBreak.join(vs); } if (hasDefault) vset = newctx.vsBreak; return ctx.removeAdditionalVars(vset); }
Inline
/** * Inline */
public Statement inline(Environment env, Context ctx) { ctx = new Context(ctx, this); expr = expr.inlineValue(env, ctx); for (int i = 0 ; i < args.length ; i++) { if (args[i] != null) { args[i] = args[i].inline(env, ctx); } } return this; }
Create a copy of the statement for method inlining
/** * Create a copy of the statement for method inlining */
public Statement copyInline(Context ctx, boolean valNeeded) { SwitchStatement s = (SwitchStatement)clone(); s.expr = expr.copyInline(ctx); s.args = new Statement[args.length]; for (int i = 0 ; i < args.length ; i++) { if (args[i] != null) { s.args[i] = args[i].copyInline(ctx, valNeeded); } } return s; }
The cost of inlining this statement
/** * The cost of inlining this statement */
public int costInline(int thresh, Environment env, Context ctx) { int cost = expr.costInline(thresh, env, ctx); for (int i = 0 ; (i < args.length) && (cost < thresh) ; i++) { if (args[i] != null) { cost += args[i].costInline(thresh, env, ctx); } } return cost; }
Code
/** * Code */
public void code(Environment env, Context ctx, Assembler asm) { CodeContext newctx = new CodeContext(ctx, this); expr.codeValue(env, newctx, asm); SwitchData sw = new SwitchData(); boolean hasDefault = false; for (int i = 0 ; i < args.length ; i++) { Statement s = args[i]; if ((s != null) && (s.op == CASE)) { Expression e = ((CaseStatement)s).expr; if (e != null) { sw.add(((IntegerExpression)e).value, new Label()); } // JCOV else { hasDefault = true; } // end JCOV } } // JCOV if (env.coverage()) sw.initTableCase(); // end JCOV asm.add(where, opc_tableswitch, sw); for (int i = 0 ; i < args.length ; i++) { Statement s = args[i]; if (s != null) { if (s.op == CASE) { Expression e = ((CaseStatement)s).expr; if (e != null) { asm.add(sw.get(((IntegerExpression)e).value)); // JCOV sw.addTableCase(((IntegerExpression)e).value, s.where); // end JCOV } else { asm.add(sw.getDefaultLabel()); // JCOV sw.addTableDefault(s.where); // end JCOV /* JCOV hasDefault = true; end JCOV */ } } else { s.code(env, newctx, asm); } } } if (!hasDefault) { asm.add(sw.getDefaultLabel()); } asm.add(newctx.breakLabel); }
Print
/** * Print */
public void print(PrintStream out, int indent) { super.print(out, indent); out.print("switch ("); expr.print(out); out.print(") {\n"); for (int i = 0 ; i < args.length ; i++) { if (args[i] != null) { printIndent(out, indent + 1); args[i].print(out, indent + 1); out.print("\n"); } } printIndent(out, indent); out.print("}"); } }