public void generateCode(BlockScope currentScope, CodeStream codeStream) {
    if ((this.bits & IsReachable) == 0) {
      return;
    }
    int pc = codeStream.position;

    if (this.assertionSyntheticFieldBinding != null) {
      BranchLabel assertionActivationLabel = new BranchLabel(codeStream);
      codeStream.fieldAccess(
          Opcodes.OPC_getstatic,
          this.assertionSyntheticFieldBinding,
          null /* default declaringClass */);
      codeStream.ifne(assertionActivationLabel);

      BranchLabel falseLabel;
      this.assertExpression.generateOptimizedBoolean(
          currentScope, codeStream, (falseLabel = new BranchLabel(codeStream)), null, true);
      codeStream.newJavaLangAssertionError();
      codeStream.dup();
      if (this.exceptionArgument != null) {
        this.exceptionArgument.generateCode(currentScope, codeStream, true);
        codeStream.invokeJavaLangAssertionErrorConstructor(
            this.exceptionArgument.implicitConversion & 0xF);
      } else {
        codeStream.invokeJavaLangAssertionErrorDefaultConstructor();
      }
      codeStream.athrow();

      // May loose some local variable initializations : affecting the local variable attributes
      if (this.preAssertInitStateIndex != -1) {
        codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.preAssertInitStateIndex);
      }
      falseLabel.place();
      assertionActivationLabel.place();
    } else {
      // May loose some local variable initializations : affecting the local variable attributes
      if (this.preAssertInitStateIndex != -1) {
        codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.preAssertInitStateIndex);
      }
    }
    codeStream.recordPositionsFrom(pc, this.sourceStart);
  }
示例#2
0
  /**
   * Try statement code generation with or without jsr bytecode use post 1.5 target level, cannot
   * use jsr bytecode, must instead inline finally block returnAddress is only allocated if jsr is
   * allowed
   */
  public void generateCode(BlockScope currentScope, CodeStream codeStream) {
    if ((bits & IsReachableMASK) == 0) {
      return;
    }
    // in case the labels needs to be reinitialized
    // when the code generation is restarted in wide mode
    if (this.anyExceptionLabelsCount > 0) {
      this.anyExceptionLabels = NO_EXCEPTION_HANDLER;
      this.anyExceptionLabelsCount = 0;
    }
    int pc = codeStream.position;
    final int NO_FINALLY = 0; // no finally block
    final int FINALLY_SUBROUTINE =
        1; // finally is generated as a subroutine (using jsr/ret bytecodes)
    final int FINALLY_DOES_NOT_COMPLETE =
        2; // non returning finally is optimized with only one instance of finally block
    final int FINALLY_MUST_BE_INLINED =
        3; // finally block must be inlined since cannot use jsr/ret bytecodes >1.5
    int finallyMode;
    if (subRoutineStartLabel == null) {
      finallyMode = NO_FINALLY;
    } else {
      if (this.isSubRoutineEscaping) {
        finallyMode = FINALLY_DOES_NOT_COMPLETE;
      } else if (scope.compilerOptions().inlineJsrBytecode) {
        finallyMode = FINALLY_MUST_BE_INLINED;
      } else {
        finallyMode = FINALLY_SUBROUTINE;
      }
    }
    boolean requiresNaturalExit = false;
    // preparing exception labels
    int maxCatches;
    ExceptionLabel[] exceptionLabels =
        new ExceptionLabel[maxCatches = catchArguments == null ? 0 : catchArguments.length];
    for (int i = 0; i < maxCatches; i++) {
      exceptionLabels[i] = new ExceptionLabel(codeStream, catchArguments[i].binding.type);
    }
    if (subRoutineStartLabel != null) {
      subRoutineStartLabel.initialize(codeStream);
      this.enterAnyExceptionHandler(codeStream);
    }
    // generate the try block
    tryBlock.generateCode(scope, codeStream);
    boolean tryBlockHasSomeCode = codeStream.position != pc;
    // flag telling if some bytecodes were issued inside the try block

    // place end positions of user-defined exception labels
    if (tryBlockHasSomeCode) {
      // natural exit may require subroutine invocation (if finally != null)
      Label naturalExitLabel = new Label(codeStream);
      if (!tryBlockExit) {
        int position = codeStream.position;
        switch (finallyMode) {
          case FINALLY_SUBROUTINE:
          case FINALLY_MUST_BE_INLINED:
            requiresNaturalExit = true;
            // fall through
          case NO_FINALLY:
            codeStream.goto_(naturalExitLabel);
            break;
          case FINALLY_DOES_NOT_COMPLETE:
            codeStream.goto_(subRoutineStartLabel);
            break;
        }
        codeStream.updateLastRecordedEndPC(tryBlock.scope, position);
        // goto is tagged as part of the try block
      }
      for (int i = 0; i < maxCatches; i++) {
        exceptionLabels[i].placeEnd();
      }
      /* generate sequence of handler, all starting by storing the TOS (exception
      thrown) into their own catch variables, the one specified in the source
      that must denote the handled exception.
      */
      if (catchArguments != null) {
        for (int i = 0; i < maxCatches; i++) {
          // May loose some local variable initializations : affecting the local variable attributes
          if (preTryInitStateIndex != -1) {
            codeStream.removeNotDefinitelyAssignedVariables(currentScope, preTryInitStateIndex);
          }
          exceptionLabels[i].place();
          codeStream.incrStackSize(1);
          // optimizing the case where the exception variable is not actually used
          LocalVariableBinding catchVar;
          int varPC = codeStream.position;
          if ((catchVar = catchArguments[i].binding).resolvedPosition != -1) {
            codeStream.store(catchVar, false);
            catchVar.recordInitializationStartPC(codeStream.position);
            codeStream.addVisibleLocalVariable(catchVar);
          } else {
            codeStream.pop();
          }
          codeStream.recordPositionsFrom(varPC, catchArguments[i].sourceStart);
          // Keep track of the pcs at diverging point for computing the local attribute
          // since not passing the catchScope, the block generation will exitUserScope(catchScope)
          catchBlocks[i].generateCode(scope, codeStream);
          if (!catchExits[i]) {
            switch (finallyMode) {
              case FINALLY_SUBROUTINE:
              case FINALLY_MUST_BE_INLINED:
                requiresNaturalExit = true;
                // fall through
              case NO_FINALLY:
                codeStream.goto_(naturalExitLabel);
                break;
              case FINALLY_DOES_NOT_COMPLETE:
                codeStream.goto_(subRoutineStartLabel);
                break;
            }
          }
        }
      }
      this.exitAnyExceptionHandler();
      // extra handler for trailing natural exit (will be fixed up later on when natural exit is
      // generated below)
      ExceptionLabel naturalExitExceptionHandler =
          finallyMode == FINALLY_SUBROUTINE && requiresNaturalExit
              ? new ExceptionLabel(codeStream, null)
              : null;

      // addition of a special handler so as to ensure that any uncaught exception (or exception
      // thrown
      // inside catch blocks) will run the finally block
      int finallySequenceStartPC = codeStream.position;
      if (subRoutineStartLabel != null) {
        this.placeAllAnyExceptionHandlers();
        if (naturalExitExceptionHandler != null) naturalExitExceptionHandler.place();

        if (preTryInitStateIndex != -1) {
          // reset initialization state, as for a normal catch block
          codeStream.removeNotDefinitelyAssignedVariables(currentScope, preTryInitStateIndex);
        }

        codeStream.incrStackSize(1);
        switch (finallyMode) {
          case FINALLY_SUBROUTINE:
            codeStream.store(anyExceptionVariable, false);
            codeStream.jsr(subRoutineStartLabel);
            codeStream.recordPositionsFrom(finallySequenceStartPC, finallyBlock.sourceStart);
            int position = codeStream.position;
            codeStream.load(anyExceptionVariable);
            codeStream.athrow();
            codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
            subRoutineStartLabel.place();
            codeStream.incrStackSize(1);
            position = codeStream.position;
            codeStream.store(returnAddressVariable, false);
            codeStream.recordPositionsFrom(position, finallyBlock.sourceStart);
            finallyBlock.generateCode(scope, codeStream);
            position = codeStream.position;
            codeStream.ret(returnAddressVariable.resolvedPosition);
            //						codeStream.updateLastRecordedEndPC(position);
            codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
            // the ret bytecode is part of the subroutine
            break;
          case FINALLY_MUST_BE_INLINED:
            codeStream.store(anyExceptionVariable, false);
            codeStream.recordPositionsFrom(finallySequenceStartPC, finallyBlock.sourceStart);
            this.finallyBlock.generateCode(currentScope, codeStream);
            position = codeStream.position;
            codeStream.load(anyExceptionVariable);
            codeStream.athrow();
            subRoutineStartLabel.place();
            codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
            break;
          case FINALLY_DOES_NOT_COMPLETE:
            codeStream.pop();
            subRoutineStartLabel.place();
            codeStream.recordPositionsFrom(finallySequenceStartPC, finallyBlock.sourceStart);
            finallyBlock.generateCode(scope, codeStream);
            break;
        }
        // will naturally fall into subsequent code after subroutine invocation
        naturalExitLabel.place();
        if (requiresNaturalExit) {
          switch (finallyMode) {
            case FINALLY_SUBROUTINE:
              int position = codeStream.position;
              // fix up natural exit handler
              naturalExitExceptionHandler.placeStart();
              codeStream.jsr(subRoutineStartLabel);
              naturalExitExceptionHandler.placeEnd();
              codeStream.recordPositionsFrom(position, finallyBlock.sourceEnd);
              break;
            case FINALLY_MUST_BE_INLINED:
              // May loose some local variable initializations : affecting the local variable
              // attributes
              // needed since any exception handler got inlined subroutine
              if (preTryInitStateIndex != -1) {
                codeStream.removeNotDefinitelyAssignedVariables(currentScope, preTryInitStateIndex);
              }
              // entire sequence for finally is associated to finally block
              finallyBlock.generateCode(scope, codeStream);
              break;
            case FINALLY_DOES_NOT_COMPLETE:
              break;
          }
        }
      } else {
        // no subroutine, simply position end label (natural exit == end)
        naturalExitLabel.place();
      }
    } else {
      // try block had no effect, only generate the body of the finally block if any
      if (subRoutineStartLabel != null) {
        finallyBlock.generateCode(scope, codeStream);
      }
    }
    // May loose some local variable initializations : affecting the local variable attributes
    if (mergedInitStateIndex != -1) {
      codeStream.removeNotDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
      codeStream.addDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
    }
    codeStream.recordPositionsFrom(pc, this.sourceStart);
  }