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Add ClassLoader support for ASM ClassWriter
For bigger and more complicated classes org.objectweb.asm.ClassWriter requires access to classloader where can found classes used in transformed class. Also add a warning when a class cannot be transformed.
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8 files changed

+181
-27
lines changed

8 files changed

+181
-27
lines changed

‎src/it/projects/mexec-gh-389-block-exit-non-zero/verify.groovy

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,7 @@
1717
def buildLogLines = new File( basedir, "build.log" ).readLines()
1818

1919
// Find "System::exit was called" line index
20-
def infoMessageLineNumber = buildLogLines.indexOf("[INFO] System::exit was called with return code 123")
20+
def infoMessageLineNumber = buildLogLines.indexOf("[ERROR] System::exit was called with return code 123")
2121
assert infoMessageLineNumber > 0
2222
// Verify that preceding line is program output
2323
assert buildLogLines[infoMessageLineNumber - 1].contains("[one, two, three]")

‎src/it/projects/mexec-gh-389-block-exit-write-classloder/dbchangelog-4.31.xsd

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,8 @@
1+
<?xml version="1.0" encoding="UTF-8"?>
2+
3+
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
4+
targetNamespace="http://www.liquibase.org/xml/ns/dbchangelog"
5+
xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
6+
elementFormDefault="qualified">
7+
8+
</xsd:schema>

‎src/it/projects/mexec-gh-389-block-exit-write-classloder/invoker.properties

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,2 @@
1+
invoker.goals = package
2+
invoker.debug = false

‎src/it/projects/mexec-gh-389-block-exit-write-classloder/pom.xml

Lines changed: 78 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,78 @@
1+
<?xml version="1.0" encoding="UTF-8"?>
2+
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3+
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4+
<modelVersion>4.0.0</modelVersion>
5+
6+
<parent>
7+
<groupId>org.codehaus.mojo.exec.it</groupId>
8+
<artifactId>parent</artifactId>
9+
<version>0.1</version>
10+
</parent>
11+
12+
<artifactId>mexec-gh-389</artifactId>
13+
<version>0.0.1-SNAPSHOT</version>
14+
15+
<description>
16+
For bigger and more complicated classes org.objectweb.asm.ClassWriter
17+
requires access to classloader where can found classes used in transformed class.
18+
</description>
19+
20+
<properties>
21+
<xsd-file>dbchangelog-4.31</xsd-file>
22+
</properties>
23+
24+
<dependencies>
25+
<dependency>
26+
<groupId>net.java.dev.msv</groupId>
27+
<artifactId>msv-rngconverter</artifactId>
28+
<version>2022.7</version>
29+
</dependency>
30+
<dependency>
31+
<groupId>org.relaxng</groupId>
32+
<artifactId>trang</artifactId>
33+
<version>20241231</version>
34+
</dependency>
35+
</dependencies>
36+
37+
<build>
38+
<plugins>
39+
<plugin>
40+
<groupId>org.codehaus.mojo</groupId>
41+
<artifactId>exec-maven-plugin</artifactId>
42+
<version>@project.version@</version>
43+
<executions>
44+
<execution>
45+
<id>convert-xsd-to-rng</id>
46+
<phase>package</phase>
47+
<goals>
48+
<goal>java</goal>
49+
</goals>
50+
<configuration>
51+
<mainClass>com.sun.msv.writer.relaxng.Driver</mainClass>
52+
<commandlineArgs>
53+
${project.basedir}/${xsd-file}.xsd
54+
${project.build.directory}/${xsd-file}.rng
55+
</commandlineArgs>
56+
</configuration>
57+
</execution>
58+
<execution>
59+
<id>convert-liquibase-rng-to-rnc</id>
60+
<phase>package</phase>
61+
<goals>
62+
<goal>java</goal>
63+
</goals>
64+
<configuration>
65+
<mainClass>com.thaiopensource.relaxng.translate.Driver</mainClass>
66+
<blockSystemExit>true</blockSystemExit>
67+
<arguments>
68+
<argument>${project.build.directory}/${xsd-file}.rng</argument>
69+
<argument>${project.build.directory}/${xsd-file}.rnc</argument>
70+
</arguments>
71+
</configuration>
72+
</execution>
73+
</executions>
74+
</plugin>
75+
</plugins>
76+
</build>
77+
78+
</project>

‎src/it/projects/mexec-gh-389-block-exit-write-classloder/verify.groovy

Lines changed: 22 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,22 @@
1+
/*
2+
* Copyright MojoHaus and Contributors
3+
*
4+
* Licensed under the Apache License, Version 2.0 (the "License");
5+
* you may not use this file except in compliance with the License.
6+
* You may obtain a copy of the License at
7+
*
8+
* http://www.apache.org/licenses/LICENSE-2.0
9+
*
10+
* Unless required by applicable law or agreed to in writing, software
11+
* distributed under the License is distributed on an "AS IS" BASIS,
12+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13+
* See the License for the specific language governing permissions and
14+
* limitations under the License.
15+
*/
16+
17+
def buildLogLines = new File(basedir, "build.log").text
18+
19+
assert buildLogLines.contains("[INFO] System::exit was called with return code 0")
20+
21+
assert new File(basedir,'target/dbchangelog-4.31.rnc').exists()
22+
assert new File(basedir,'target/dbchangelog-4.31.rng').exists()

‎src/main/java/org/codehaus/mojo/exec/BlockExitTransformer.java

Lines changed: 39 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -19,9 +19,13 @@
1919
* under the License.
2020
*/
2121

22+
import java.io.IOException;
2223
import java.lang.instrument.ClassFileTransformer;
24+
import java.lang.instrument.IllegalClassFormatException;
25+
import java.net.URLClassLoader;
2326
import java.security.ProtectionDomain;
2427

28+
import org.apache.maven.plugin.logging.Log;
2529
import org.objectweb.asm.ClassReader;
2630
import org.objectweb.asm.ClassVisitor;
2731
import org.objectweb.asm.ClassWriter;
@@ -33,24 +37,57 @@
3337
import static org.objectweb.asm.Opcodes.ASM9;
3438

3539
public class BlockExitTransformer implements ClassFileTransformer {
40+
41+
private final URLClassLoader classLoader;
42+
43+
private final Log logger;
44+
45+
BlockExitTransformer(URLClassLoader classLoader, Log logger) {
46+
this.classLoader = classLoader;
47+
this.logger = logger;
48+
}
49+
3650
@Override
3751
public byte[] transform(
3852
final ClassLoader loader,
3953
final String className,
4054
final Class<?> classBeingRedefined,
4155
final ProtectionDomain protectionDomain,
42-
final byte[] classfileBuffer) {
56+
final byte[] classfileBuffer)
57+
throws IllegalClassFormatException {
4358
try {
4459
final ClassReader reader = new ClassReader(classfileBuffer);
45-
final ClassWriter writer = new ClassWriter(COMPUTE_FRAMES);
60+
final ClassWriter writer = createClassWriter();
4661
final SystemExitOverrideVisitor visitor = new SystemExitOverrideVisitor(writer);
4762
reader.accept(visitor, EXPAND_FRAMES);
4863
return writer.toByteArray();
4964
} catch (final RuntimeException re) { // too old asm for ex, ignore these classes to not block the rest
65+
logger.warn("Unable to transform class " + className + " : " + re.getMessage());
5066
return null;
5167
}
5268
}
5369

70+
/**
71+
* Creates a new {@link ClassWriter} that uses the dedicated {@link ClassLoader} of this transformer.
72+
* <p>
73+
* For bigger and more complicated classes {@link ClassWriter}
74+
* requires access to classloader where can found classes used in transformed class.
75+
*
76+
* @return a new {@link ClassWriter}
77+
*/
78+
private ClassWriter createClassWriter() {
79+
return new ClassWriter(COMPUTE_FRAMES) {
80+
@Override
81+
protected ClassLoader getClassLoader() {
82+
return classLoader;
83+
}
84+
};
85+
}
86+
87+
public void close() throws IOException {
88+
classLoader.close();
89+
}
90+
5491
private static class SystemExitOverrideVisitor extends ClassVisitor {
5592
private static final String SYSTEM_REPLACEMENT =
5693
SystemExitManager.class.getName().replace('.', '/');

‎src/main/java/org/codehaus/mojo/exec/ExecJavaMojo.java

Lines changed: 7 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -264,12 +264,6 @@ public void execute() throws MojoExecutionException, MojoFailureException {
264264
}
265265

266266
IsolatedThreadGroup threadGroup = new IsolatedThreadGroup(mainClass /* name */);
267-
// TODO:
268-
// Adjust implementation for future JDKs after removal of SecurityManager.
269-
// See https://openjdk.org/jeps/411 for basic information.
270-
// See https://bugs.openjdk.org/browse/JDK-8199704 for details about how users might be able to
271-
// block
272-
// System::exit in post-removal JDKs (still undecided at the time of writing this comment).
273267
Thread bootstrapThread = new Thread( // TODO: drop this useless thread 99% of the time
274268
threadGroup,
275269
() -> {
@@ -299,9 +293,11 @@ public void execute() throws MojoExecutionException, MojoFailureException {
299293
.getThreadGroup()
300294
.uncaughtException(Thread.currentThread(), exceptionToReport);
301295
} catch (SystemExitException systemExitException) {
302-
getLog().info(systemExitException.getMessage());
303296
if (systemExitException.getExitCode() != 0) {
297+
getLog().error(systemExitException.getMessage());
304298
throw systemExitException;
299+
} else {
300+
getLog().info(systemExitException.getMessage());
305301
}
306302
} catch (Throwable e) { // just pass it on
307303
Thread.currentThread().getThreadGroup().uncaughtException(Thread.currentThread(), e);
@@ -696,16 +692,14 @@ private URLClassLoader getClassLoader() throws MojoExecutionException {
696692
this.addRelevantProjectDependenciesToClasspath(classpathURLs);
697693
this.addAdditionalClasspathElements(classpathURLs);
698694
try {
699-
final URLClassLoaderBuilder builder = URLClassLoaderBuilder.builder()
695+
return URLClassLoaderBuilder.builder()
700696
.setLogger(getLog())
701697
.setPaths(classpathURLs)
702698
.setExclusions(classpathFilenameExclusions)
703699
.setForcedJvmPackages(forcedJvmPackages)
704-
.setExcludedJvmPackages(excludedJvmPackages);
705-
if (blockSystemExit) {
706-
builder.setTransformer(new BlockExitTransformer());
707-
}
708-
return builder.build();
700+
.setExcludedJvmPackages(excludedJvmPackages)
701+
.withTransformers(blockSystemExit)
702+
.build();
709703
} catch (NullPointerException | IOException e) {
710704
throw new MojoExecutionException(e.getMessage(), e);
711705
}

‎src/main/java/org/codehaus/mojo/exec/URLClassLoaderBuilder.java

Lines changed: 24 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -23,7 +23,6 @@
2323
import java.io.File;
2424
import java.io.IOException;
2525
import java.io.InputStream;
26-
import java.lang.instrument.ClassFileTransformer;
2726
import java.lang.instrument.IllegalClassFormatException;
2827
import java.net.MalformedURLException;
2928
import java.net.URL;
@@ -51,7 +50,7 @@ class URLClassLoaderBuilder {
5150
private List<String> excludedJvmPackages;
5251
private Collection<Path> paths;
5352
private Collection<String> exclusions;
54-
private ClassFileTransformer transformer;
53+
private boolean withTransformers;
5554

5655
private URLClassLoaderBuilder() {}
5756

@@ -69,11 +68,6 @@ URLClassLoaderBuilder setForcedJvmPackages(List<String> forcedJvmPackages) {
6968
return this;
7069
}
7170

72-
public URLClassLoaderBuilder setTransformer(final ClassFileTransformer transformer) {
73-
this.transformer = transformer;
74-
return this;
75-
}
76-
7771
URLClassLoaderBuilder setLogger(Log logger) {
7872
this.logger = logger;
7973
return this;
@@ -89,6 +83,11 @@ URLClassLoaderBuilder setPaths(Collection<Path> paths) {
8983
return this;
9084
}
9185

86+
URLClassLoaderBuilder withTransformers(boolean wiTransformers) {
87+
this.withTransformers = wiTransformers;
88+
return this;
89+
}
90+
9291
URLClassLoader build() throws IOException {
9392
List<URL> urls = new ArrayList<>(paths.size());
9493

@@ -107,7 +106,13 @@ URLClassLoader build() throws IOException {
107106
}
108107
}
109108

110-
return new ExecJavaClassLoader(urls.toArray(new URL[0]), transformer, forcedJvmPackages, excludedJvmPackages);
109+
URL[] urlsArray = urls.toArray(new URL[0]);
110+
BlockExitTransformer transformer = null;
111+
if (withTransformers) {
112+
transformer = new BlockExitTransformer(new URLClassLoader(urlsArray), logger);
113+
}
114+
115+
return new ExecJavaClassLoader(urlsArray, transformer, forcedJvmPackages, excludedJvmPackages);
111116
}
112117

113118
// child first strategy
@@ -121,13 +126,13 @@ private static class ExecJavaClassLoader extends URLClassLoader {
121126
}
122127

123128
private final String jre;
124-
private final ClassFileTransformer transformer;
129+
private final BlockExitTransformer transformer;
125130
private final List<String> forcedJvmPackages;
126131
private final List<String> excludedJvmPackages;
127132

128133
public ExecJavaClassLoader(
129134
URL[] urls,
130-
ClassFileTransformer transformer,
135+
BlockExitTransformer transformer,
131136
List<String> forcedJvmPackages,
132137
List<String> excludedJvmPackages) {
133138
super(urls);
@@ -137,6 +142,14 @@ public ExecJavaClassLoader(
137142
this.excludedJvmPackages = excludedJvmPackages;
138143
}
139144

145+
@Override
146+
public void close() throws IOException {
147+
super.close();
148+
if (transformer != null) {
149+
transformer.close();
150+
}
151+
}
152+
140153
@Override
141154
public Class<?> loadClass(final String name, final boolean resolve) throws ClassNotFoundException {
142155
if (name == null) {
@@ -208,7 +221,7 @@ private Class<?> doFindClass(final String name) throws ClassNotFoundException {
208221

209222
try (final InputStream inputStream = url.openStream()) {
210223
final byte[] raw = IOUtil.toByteArray(inputStream);
211-
final byte[] res = transformer.transform(this, name, null, null, raw);
224+
final byte[] res = transformer.transform(null, name, null, null, raw);
212225
final byte[] bin = res == null ? raw : res;
213226
return super.defineClass(name, bin, 0, bin.length);
214227
} catch (final ClassFormatError | IOException | IllegalClassFormatException var4) {

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