From 92f7046e3fe82bdb8f47aca0e7019aa2fe304c3e Mon Sep 17 00:00:00 2001 From: jochen Date: Sat, 3 Oct 1998 10:05:21 +0000 Subject: [PATCH] *** empty log message *** git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@50 379699f6-c40d-0410-875b-85095c16579e --- jode/jode/flow/FlowBlock.java | 430 +++++++++++++++++--------------- jode/jode/flow/SwitchBlock.java | 5 + 2 files changed, 237 insertions(+), 198 deletions(-) diff --git a/jode/jode/flow/FlowBlock.java b/jode/jode/flow/FlowBlock.java index 60bacc3..4583e88 100644 --- a/jode/jode/flow/FlowBlock.java +++ b/jode/jode/flow/FlowBlock.java @@ -145,7 +145,9 @@ public class FlowBlock { /** * This method optimizes the jumps to successor. - * Returns the new appendBlock, it may have changed. + * @param successor The successing flow block + * @param appendBlock the block where the successor is appended to. + * @return the new appendBlock, it may have changed. */ public StructuredBlock optimizeJumps(FlowBlock successor, StructuredBlock appendBlock) { @@ -374,6 +376,98 @@ public class FlowBlock { return appendBlock; } + /** + * Move the successors of the given flow block to this flow block. + * @param succ the other flow block + */ + void mergeSuccessors(FlowBlock succ) { + /* Merge the sucessors from the successing flow block + */ + Enumeration enum = succ.successors.elements(); + while (enum.hasMoreElements()) { + Jump jump = (Jump) enum.nextElement(); + if (jump == null) + continue; + successors.addElement(jump); + if (jump.destination.predecessors.contains(succ)) { + /*XXX comment and make clearer, better etc.*/ + jump.destination.predecessors.removeElement(succ); + if (!jump.destination.predecessors.contains(this)) + jump.destination.predecessors.addElement(this); + } + } + } + + /** + * Resolve remaining jumps to the successor by generating break + * instructions. As last resort generate a do while(false) block. + * @param successor The successing flow block + * @param appendBlock the block where the successor is appended to. + * @return the new appendBlock, it may have changed. + */ + StructuredBlock resolveRemaining(FlowBlock succ, + StructuredBlock appendBlock) { + LoopBlock doWhileFalse = null; + Enumeration enum = successors.elements(); + next_jump: + while (enum.hasMoreElements()) { + Jump jump = (Jump) enum.nextElement(); + + if (jump == null || jump.destination != succ + || jump.prev == appendBlock) + continue; + + int breaklevel = 0; + BreakableBlock breakToBlock = null; + for (StructuredBlock surrounder = jump.prev.outer; + surrounder != null && surrounder != appendBlock.outer; + surrounder = surrounder.outer) { + if (surrounder instanceof BreakableBlock) { + breaklevel++; + if (surrounder.getNextFlowBlock() == succ) { + breakToBlock = (BreakableBlock) surrounder; + break; + } + } + } + + StructuredBlock prevBlock = jump.prev; + prevBlock.removeJump(); + + if (breakToBlock == null) { + /* Nothing else helped, so put a do/while(0) + * block around appendBlock and break to that + * block. + */ + if (doWhileFalse == null) { + doWhileFalse = new LoopBlock(LoopBlock.DOWHILE, + LoopBlock.FALSE); + doWhileFalse.setJump(new Jump(succ)); + successors.addElement(doWhileFalse.jump); + } + prevBlock.appendBlock + (new BreakBlock(doWhileFalse, breaklevel > 0)); + } else + prevBlock.appendBlock + (new BreakBlock(breakToBlock, breaklevel > 1)); + } + + if (doWhileFalse != null) { + doWhileFalse.replace(appendBlock, appendBlock); + doWhileFalse.setBody(appendBlock); + doWhileFalse.removeJump(); + } + + /* Now remove the jump of the appendBlock if it points to + * successor. + */ + if (appendBlock.jump != null + && appendBlock.jump.destination == succ) + appendBlock.removeJump(); + + return appendBlock; + } + /** * Updates the in/out-Vectors of the structured block of the * successing flow block simultanous to a T1 transformation. @@ -497,34 +591,45 @@ public class FlowBlock { public void checkConsistent() { if (!Decompiler.doChecks) return; - if (block.outer != null || block.flowBlock != this) { - throw new RuntimeException("Inconsistency"); - } - block.checkConsistent(); - Enumeration enum = successors.elements(); - while (enum.hasMoreElements()) { - Jump jump = (Jump) enum.nextElement(); - if (jump == null) - continue; - - if (jump.prev.flowBlock != this || - jump.prev.jump != jump) +// try { + if (block.outer != null || block.flowBlock != this) { throw new RuntimeException("Inconsistency"); - - StructuredBlock sb = jump.prev; - while (sb != block) { - if (sb.outer == null) - throw new RuntimeException("Inconsistency"); - StructuredBlock[] blocks = sb.outer.getSubBlocks(); - int i; - for (i=0; i 0)); - } else - prevBlock.appendBlock - (new BreakBlock(breakToBlock, breaklevel > 1)); - } - - if (doWhileFalse != null) { - doWhileFalse.replace(appendBlock, appendBlock); - doWhileFalse.setBody(appendBlock); - } + checkConsistent(); - /* Now remove the jump of the appendBlock if it points to - * successor. - */ - if (appendBlock.jump != null - && appendBlock.jump.destination == succ) - appendBlock.removeJump(); + appendBlock = resolveRemaining(succ, appendBlock); } /* Believe it or not: Now the rule, that the first part of a @@ -774,21 +779,11 @@ public class FlowBlock { length += succ.length; /* T1 transformation succeeded */ - try { - checkConsistent(); - } catch (RuntimeException ex) { - ex.printStackTrace(); - try { - jode.TabbedPrintWriter writer = - new jode.TabbedPrintWriter(System.err, " "); - writer.tab(); - block.dumpSource(writer); - } catch (java.io.IOException ioex) { - } - } + checkConsistent(); return true; } + public boolean doT2(int start, int end) { /* If there are no jumps to the beginning of this flow block * or if this block has other predecessors with a higher @@ -806,18 +801,7 @@ public class FlowBlock { } } - try { - checkConsistent(); - } catch (RuntimeException ex) { - ex.printStackTrace(); - try { - jode.TabbedPrintWriter writer = - new jode.TabbedPrintWriter(System.err, " "); - writer.tab(); - block.dumpSource(writer); - } catch (java.io.IOException ioex) { - } - } + checkConsistent(); /* Update the in/out-Vectors now */ updateInOut(this, false); @@ -922,18 +906,7 @@ public class FlowBlock { predecessors.removeElement(this); /* T2 analysis succeeded */ - try { - checkConsistent(); - } catch (RuntimeException ex) { - ex.printStackTrace(); - try { - jode.TabbedPrintWriter writer = - new jode.TabbedPrintWriter(System.err, " "); - writer.tab(); - block.dumpSource(writer); - } catch (java.io.IOException ioex) { - } - } + checkConsistent(); return true; } @@ -943,18 +916,7 @@ public class FlowBlock { * Do a T1 transformation with the end_of_method block. */ public void mergeEndBlock() { - try{ - checkConsistent(); - } catch (RuntimeException ex) { - ex.printStackTrace(); - try { - jode.TabbedPrintWriter writer = - new jode.TabbedPrintWriter(System.err, " "); - writer.tab(); - block.dumpSource(writer); - } catch (java.io.IOException ioex) { - } - } + checkConsistent(); /* First find the innermost block that contains all jumps to the * END_OF_METHOD block. @@ -1032,18 +994,7 @@ public class FlowBlock { appendBlock.removeJump(); /* transformation succeeded */ - try { - checkConsistent(); - } catch (RuntimeException ex) { - ex.printStackTrace(); - try { - jode.TabbedPrintWriter writer = - new jode.TabbedPrintWriter(System.err, " "); - writer.tab(); - block.dumpSource(writer); - } catch (java.io.IOException ioex) { - } - } + checkConsistent(); } @@ -1161,14 +1112,22 @@ public class FlowBlock { */ return changed; } else { - if (succ.block instanceof RawTryCatchBlock) { - int subStart = succ.addr; - int subEnd = (subStart > addr)? end : addr; - succ.analyze(subStart, subEnd); - } /* Only do T1 transformation if the blocks are * adjacent. */ - if ((succ.addr == addr+length + if (succ.block instanceof SwitchBlock) { + /* analyze succ, the new region is the + * continous region of + * [start,end) \cap \compl [addr, addr+length) + * where succ.addr lies in. + */ + int newStart = (succ.addr > addr) + ? addr+length : start; + int newEnd = (succ.addr > addr) + ? end : addr; + if (succ.analyzeSwitch(newStart, newEnd)) + break; + + } if ((succ.addr == addr+length || succ.addr+succ.length == addr) && doT1(succ)) { /* T1 transformation succeeded. */ @@ -1206,7 +1165,82 @@ public class FlowBlock { } } + /** + * The switch analyzation. This calls doSwitchT1 and doT2 on apropriate + * regions. Only blocks whose address lies in the given address + * range are considered and it is taken care of, that the switch + * is never leaved.

+ * The current flow block must contain the switch block as main + * block. + * @param start the start of the address range. + * @param end the end of the address range. + */ + public boolean analyzeSwitch(int start, int end) { + SwitchBlock switchBlock = (SwitchBlock) block; + boolean changed = false; + StructuredBlock lastBlock = null; + lastModified = block; + /* XXX - move to switchBlock??? */ + for (int i=0; i < switchBlock.caseBlocks.length; i++) { + if (switchBlock.caseBlocks[i].subBlock != null + && switchBlock.caseBlocks[i].subBlock.jump != null) { + FlowBlock next = switchBlock.caseBlocks[i]. + subBlock.jump.destination; + if (next.addr >= end) + return changed; + else if (next.addr >= start) { + /* First analyze the next block. */ + changed = next.analyze(next.addr, end) || changed; + + /* Check if next has only the previous case + * and this case as predecessor. Otherwise + * break the analysis. + */ + if (next.predecessors.size() != 1 + || next.predecessors.elementAt(0) != this) + return changed; + + boolean lastContains = false; + for (int j=0; j