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Merged pull request #114 "Grow the code for relocatables, and do fixu…
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…p, and relocate".
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@aunkrig
aunkrig committed Mar 8, 2020
1 parent 354abed commit 367c58e
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Showing 2 changed files with 118 additions and 32 deletions.
73 changes: 41 additions & 32 deletions janino/src/main/java/org/codehaus/janino/CodeContext.java
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Original file line number Diff line number Diff line change
Expand Up @@ -385,14 +385,19 @@ class LocalScope {
*/
public void
fixUpAndRelocate() {
this.maybeGrow();
this.fixUp();
this.relocate();
}

// We do this in a loop to allow relocatables to adjust the size
// of things in the byte stream. It is extremely unlikely, but possible
// that a late relocatable will grow the size of the bytecode, and require
// an earlier relocatable to switch from 32K mode to 64K mode branching
do {
this.fixUp();
} while (!this.relocate());
/**
* Grow the code if relocatables are required to.
*/
private void
maybeGrow() {
for (Relocatable relocatable : this.relocatables) {
relocatable.grow();
}
}

/**
Expand All @@ -407,20 +412,13 @@ class LocalScope {
}

/**
* Relocates all relocatables and aggregate their response into a single one.
*
* @return {@code true} if all of them relocated successfully, {@code false} if any of them needed to change size
* Relocates all relocatables.
*/
private boolean
private void
relocate() {
boolean finished = true;
for (Relocatable relocatable : this.relocatables) {

// Do not terminate earlier so that everything gets a chance to grow in the first pass changes the common
// case for this to be O(n) instead of O(n**2).
finished &= relocatable.relocate();
relocatable.relocate();
}
return finished;
}

/**
Expand Down Expand Up @@ -622,8 +620,8 @@ class Branch extends Relocatable {
}
}

@Override public boolean
relocate() {
@Override public void
grow() {
if (this.destination.offset == Offset.UNSET) {
throw new InternalCompilerException("Cannot relocate branch to unset destination offset");
}
Expand All @@ -643,9 +641,17 @@ class Branch extends Relocatable {
CodeContext.this.popInserter();
this.source.offset = pos;
this.expanded = true;
return false;
}
}

@Override public void
relocate() {
if (this.destination.offset == Offset.UNSET) {
throw new InternalCompilerException("Cannot relocate branch to unset destination offset");
}
int offset = this.destination.offset - this.source.offset;

@SuppressWarnings("deprecation") final int opcodeJsr = Opcode.JSR;
final byte[] ba;
if (!this.expanded) {
//we fit in a 16-bit jump
Expand Down Expand Up @@ -683,7 +689,6 @@ class Branch extends Relocatable {
}
}
System.arraycopy(ba, 0, CodeContext.this.code, this.source.offset, ba.length);
return true;
}

private boolean expanded; //marks whether this has been expanded to account for a wide branch
Expand Down Expand Up @@ -748,7 +753,10 @@ class OffsetBranch extends Relocatable {
this.destination = destination;
}

@Override public boolean
@Override public void
grow() {}

@Override public void
relocate() {
if (this.source.offset == Offset.UNSET || this.destination.offset == Offset.UNSET) {
throw new InternalCompilerException("Cannot relocate offset branch to unset destination offset");
Expand All @@ -761,7 +769,6 @@ class OffsetBranch extends Relocatable {
(byte) offset
};
System.arraycopy(ba, 0, CodeContext.this.code, this.where.offset, 4);
return true;
}
private final Offset where, source, destination;
}
Expand Down Expand Up @@ -1026,13 +1033,15 @@ class LineNumberOffset extends Offset {
private abstract
class Relocatable {

/**
* Grows the code if the relocation cannot be done without growing code.
*/
public abstract void grow();

/**
* Relocates this object.
*
* @return {@code true} if the relocation succeeded in place; {@code false} if the relocation grew the number
* of bytes required
*/
public abstract boolean relocate();
public abstract void relocate();
}

/**
Expand Down Expand Up @@ -1213,11 +1222,11 @@ interface FixUp {

this.relocatables.add(new Relocatable() {

@Override public boolean
relocate() {
uvi.offset = (short) o.offset;
return true;
}
@Override public void
grow() {}

@Override public void
relocate() { uvi.offset = (short) o.offset; }
});

this.pushOperand(uvi);
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77 changes: 77 additions & 0 deletions janino/src/test/java/org/codehaus/janino/tests/GithubIssuesTest.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -266,6 +266,83 @@ class GithubIssuesTest {
);
}

@Test public void
testIssue113() throws Exception {
CompileUnit unit1 = new CompileUnit("demo.pkg3", "A$$1", (
""
+ "package demo.pkg3;\n"
+ "public class A$$1 {\n"
+ " public static String main() {\n"
+ " StringBuilder sb = new StringBuilder();\n"
+ " short b = 1;\n"
+ " for (int i = 0; i < 4; i++) {\n"
+ " ;\n"
+ " switch (i) {\n"
+ " case 0:\n"
+ " sb.append(\"A\");\n"
+ " break;\n"
+ " case 1:\n"
+ " sb.append(\"B\");\n"
+ " break;\n"
+ " case 2:\n"
+ " sb.append(\"C\");\n"
+ " break;\n"
+ " case 3:\n"
+ " sb.append(\"D\");\n"
+ " break;\n"
+ " }\n"
+ GithubIssuesTest.injectDummyLargeCodeExceedingShort()
+ " }\n"
+ " return sb.toString();\n"
+ " }\n"
+ "}\n"
));

ClassLoader classLoader = this.compile(Thread.currentThread().getContextClassLoader(), unit1);

Assert.assertEquals("ABCD", classLoader.loadClass("demo.pkg3.A$$1").getMethod("main").invoke(null));
}
// java.lang.VerifyError: (class: demo/pkg3/A$$1, method: main signature: ()Ljava/lang/String;) Illegal instruction found at offset 18
// at java.lang.Class.getDeclaredMethods0(Native Method)
// at java.lang.Class.privateGetDeclaredMethods(Class.java:2436)
// at java.lang.Class.getMethod0(Class.java:2679)
// at java.lang.Class.getMethod(Class.java:1605)
// at org.codehaus.janino.tests.GithubIssuesTest.testIssue113(GithubIssuesTest.java:306)
// at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
// at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
// at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
// at java.lang.reflect.Method.invoke(Method.java:597)
// at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
// at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
// at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
// at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
// at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
// at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
// at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
// at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
// at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
// at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
// at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
// at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
// at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
// at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
// at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
// at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
// at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
// at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
// at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)


private static String
injectDummyLargeCodeExceedingShort() {
StringBuilder sb = new StringBuilder();
sb.append("int a = -1;\n");
for (int i = 0 ; i < Short.MAX_VALUE / 3 ; i++) {
sb.append("a = " + i + ";\n");
}
return sb.toString();
}

public ClassLoader
compile(ClassLoader parentClassLoader, CompileUnit... compileUnits) {

Expand Down

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