fix: consider the possibility of dup_x2 and dup_x1

Signed-off-by: Kengo TODA <skypencil@gmail.com>
spotbugs · Aug 28, 2022 · f6c00c9 · f6c00c9
1 parent d48728d
commit f6c00c9
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Showing 2 changed files with 12 additions and 39 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,7 +8,7 @@ Currently the versioning policy of this project follows [Semantic Versioning v2.
 ### Fixed
 - Bumped gson from 2.9.0 to 2.9.1 ([#2136](https://github.com/spotbugs/spotbugs/pull/2136))
 - Fixed InvalidInputException in Eclipse while bug reporting ([#2134](https://github.com/spotbugs/spotbugs/issues/2134))
-- Fixed CFGBuilderException thrown when field size is 2 (double, long) ([#2146](https://github.com/spotbugs/spotbugs/pull/2146))
+- Fixed CFGBuilderException thrown when `dup_x2` is used to swap the reference and wide-value (double, long) in the stack ([#2146](https://github.com/spotbugs/spotbugs/pull/2146))
 
 ## 4.7.1 - 2022-06-26
 ### Fixed

diff --git a/spotbugs/src/main/java/edu/umd/cs/findbugs/ba/BetterCFGBuilder2.java b/spotbugs/src/main/java/edu/umd/cs/findbugs/ba/BetterCFGBuilder2.java
@@ -35,40 +35,7 @@
 import org.apache.bcel.classfile.ClassParser;
 import org.apache.bcel.classfile.JavaClass;
 import org.apache.bcel.classfile.Method;
-import org.apache.bcel.generic.ACONST_NULL;
-import org.apache.bcel.generic.ALOAD;
-import org.apache.bcel.generic.BranchInstruction;
-import org.apache.bcel.generic.ClassGen;
-import org.apache.bcel.generic.CodeExceptionGen;
-import org.apache.bcel.generic.ConstantPoolGen;
-import org.apache.bcel.generic.ExceptionThrower;
-import org.apache.bcel.generic.GETFIELD;
-import org.apache.bcel.generic.GETSTATIC;
-import org.apache.bcel.generic.GOTO;
-import org.apache.bcel.generic.GotoInstruction;
-import org.apache.bcel.generic.ICONST;
-import org.apache.bcel.generic.IFNONNULL;
-import org.apache.bcel.generic.IFNULL;
-import org.apache.bcel.generic.IF_ACMPEQ;
-import org.apache.bcel.generic.IF_ACMPNE;
-import org.apache.bcel.generic.INSTANCEOF;
-import org.apache.bcel.generic.INVOKESTATIC;
-import org.apache.bcel.generic.IfInstruction;
-import org.apache.bcel.generic.Instruction;
-import org.apache.bcel.generic.InstructionHandle;
-import org.apache.bcel.generic.InstructionList;
-import org.apache.bcel.generic.InstructionTargeter;
-import org.apache.bcel.generic.JsrInstruction;
-import org.apache.bcel.generic.LDC;
-import org.apache.bcel.generic.MONITOREXIT;
-import org.apache.bcel.generic.MethodGen;
-import org.apache.bcel.generic.NEW;
-import org.apache.bcel.generic.NOP;
-import org.apache.bcel.generic.POP;
-import org.apache.bcel.generic.POP2;
-import org.apache.bcel.generic.PUTFIELD;
-import org.apache.bcel.generic.PUTSTATIC;
-import org.apache.bcel.generic.ReturnInstruction;
+import org.apache.bcel.generic.*;
 
 import edu.umd.cs.findbugs.SystemProperties;
 import edu.umd.cs.findbugs.ba.type.ExceptionSetFactory;
@@ -1010,7 +977,7 @@ private boolean isPEI(InstructionHandle handle) throws CFGBuilderException {
         if (ins instanceof PUTFIELD && !methodGen.isStatic()) {
             // Assume that PUTFIELD on this object is not PEI
             int depth = ins.consumeStack(cpg);
-            int fieldSize = ((PUTFIELD) ins).getFieldType(cpg).getSize();
+
             for (InstructionHandle prev = handle.getPrev(); prev != null; prev = prev.getPrev()) {
                 Instruction prevInst = prev.getInstruction();
                 if (prevInst instanceof BranchInstruction) {
@@ -1028,11 +995,17 @@ private boolean isPEI(InstructionHandle handle) throws CFGBuilderException {
                         return true;
                     }
                 }
-                depth = depth - prevInst.produceStack(cpg) + prevInst.consumeStack(cpg);
-                if (depth < fieldSize) {
+                if (prevInst instanceof DUP_X2 && depth == 4) {
+                    depth = 1;
+                } else if (prevInst instanceof DUP_X1 && depth == 3) {
+                    depth = 1;
+                } else {
+                    depth = depth - prevInst.produceStack(cpg) + prevInst.consumeStack(cpg);
+                }
+                if (depth < 1) {
                     throw new CFGBuilderException("Invalid stack at " + prev + " when checking " + handle);
                 }
-                if (depth == fieldSize) {
+                if (depth == 1) {
                     InstructionHandle prevPrev = prev.getPrev();
                     if (prevPrev != null && prevPrev.getInstruction() instanceof BranchInstruction) {
                         continue;