Yak shaving: determine covered branches for each instruction (#598)

This is required for merge of coverage information from several
instructions that cover different branches, which in his turn is
required for implementation of filter of duplicate blocks that
compilers generate for `finally`.

1 files changed, 36 insertions, 19 deletions

diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
index 328d079a..e216bb77 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
@@ -74,7 +74,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 	private final List<Instruction> instructions = new ArrayList<Instruction>();
 
 	/** List of all predecessors of covered probes */
-	private final List<Instruction> coveredProbes = new ArrayList<Instruction>();
+	private final List<CoveredProbe> coveredProbes = new ArrayList<CoveredProbe>();
 
 	/** List of all jumps encountered */
 	private final List<Jump> jumps = new ArrayList<Jump>();
@@ -177,7 +177,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 		final Instruction insn = new Instruction(currentNode, currentLine);
 		instructions.add(insn);
 		if (lastInsn != null) {
-			insn.setPredecessor(lastInsn);
+			insn.setPredecessor(lastInsn, 0);
 		}
 		final int labelCount = currentLabel.size();
 		if (labelCount > 0) {
@@ -230,7 +230,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 	@Override
 	public void visitJumpInsn(final int opcode, final Label label) {
 		visitInsn();
-		jumps.add(new Jump(lastInsn, label));
+		jumps.add(new Jump(lastInsn, label, 1));
 	}
 
 	@Override
@@ -258,11 +258,13 @@ public class MethodAnalyzer extends MethodProbesVisitor
 	private void visitSwitchInsn(final Label dflt, final Label[] labels) {
 		visitInsn();
 		LabelInfo.resetDone(labels);
-		jumps.add(new Jump(lastInsn, dflt));
+		int branch = 0;
+		jumps.add(new Jump(lastInsn, dflt, branch));
 		LabelInfo.setDone(dflt);
 		for (final Label l : labels) {
 			if (!LabelInfo.isDone(l)) {
-				jumps.add(new Jump(lastInsn, l));
+				branch++;
+				jumps.add(new Jump(lastInsn, l, branch));
 				LabelInfo.setDone(l);
 			}
 		}
@@ -275,7 +277,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 
 	@Override
 	public void visitProbe(final int probeId) {
-		addProbe(probeId);
+		addProbe(probeId, 0);
 		lastInsn = null;
 	}
 
@@ -283,13 +285,13 @@ public class MethodAnalyzer extends MethodProbesVisitor
 	public void visitJumpInsnWithProbe(final int opcode, final Label label,
 			final int probeId, final IFrame frame) {
 		visitInsn();
-		addProbe(probeId);
+		addProbe(probeId, 1);
 	}
 
 	@Override
 	public void visitInsnWithProbe(final int opcode, final int probeId) {
 		visitInsn();
-		addProbe(probeId);
+		addProbe(probeId, 0);
 	}
 
 	@Override
@@ -309,19 +311,21 @@ public class MethodAnalyzer extends MethodProbesVisitor
 		visitInsn();
 		LabelInfo.resetDone(dflt);
 		LabelInfo.resetDone(labels);
-		visitSwitchTarget(dflt);
+		int branch = 0;
+		visitSwitchTarget(dflt, branch);
 		for (final Label l : labels) {
-			visitSwitchTarget(l);
+			branch++;
+			visitSwitchTarget(l, branch);
 		}
 	}
 
-	private void visitSwitchTarget(final Label label) {
+	private void visitSwitchTarget(final Label label, final int branch) {
 		final int id = LabelInfo.getProbeId(label);
 		if (!LabelInfo.isDone(label)) {
 			if (id == LabelInfo.NO_PROBE) {
-				jumps.add(new Jump(lastInsn, label));
+				jumps.add(new Jump(lastInsn, label, branch));
 			} else {
-				addProbe(id);
+				addProbe(id, branch);
 			}
 			LabelInfo.setDone(label);
 		}
@@ -331,11 +335,12 @@ public class MethodAnalyzer extends MethodProbesVisitor
 	public void visitEnd() {
 		// Wire jumps:
 		for (final Jump j : jumps) {
-			LabelInfo.getInstruction(j.target).setPredecessor(j.source);
+			LabelInfo.getInstruction(j.target).setPredecessor(j.source,
+					j.branch);
 		}
 		// Propagate probe values:
-		for (final Instruction p : coveredProbes) {
-			p.setCovered();
+		for (final CoveredProbe p : coveredProbes) {
+			p.instruction.setCovered(p.branch);
 		}
 		// Report result:
 		coverage.ensureCapacity(firstLine, lastLine);
@@ -356,10 +361,20 @@ public class MethodAnalyzer extends MethodProbesVisitor
 		coverage.incrementMethodCounter();
 	}
 
-	private void addProbe(final int probeId) {
+	private void addProbe(final int probeId, final int branch) {
 		lastInsn.addBranch();
 		if (probes != null && probes[probeId]) {
-			coveredProbes.add(lastInsn);
+			coveredProbes.add(new CoveredProbe(lastInsn, branch));
+		}
+	}
+
+	private static class CoveredProbe {
+		final Instruction instruction;
+		final int branch;
+
+		private CoveredProbe(Instruction instruction, int branch) {
+			this.instruction = instruction;
+			this.branch = branch;
 		}
 	}
 
@@ -367,10 +382,12 @@ public class MethodAnalyzer extends MethodProbesVisitor
 
 		final Instruction source;
 		final Label target;
+		final int branch;
 
-		Jump(final Instruction source, final Label target) {
+		Jump(final Instruction source, final Label target, final int branch) {
 			this.source = source;
 			this.target = target;
+			this.branch = branch;
 		}
 	}