Report the name of missing property on compile errror

[zbynek]

Fixes #9806

Wraps cryptic NullPointerException in internal compile exception to provide more context.

I didn't find any tests that would verify correct error messages from compiling invalid modules, if you think this needs a test please give me a pointer.

[niloc132]

Can you share the new stack trace for the bug you were hunting when you discovered this?

[zbynek]

 [ERROR] An internal compiler exception occurred
com.google.gwt.dev.jjs.InternalCompilerException: Problem replacing 'org.gwtproject.safecss.ForceCheckValidStyles'
        at com.google.gwt.dev.jjs.impl.ResolvePermutationDependentValues$ValueReplacer.endVisit(ResolvePermutationDependentValues.java:77)
        at com.google.gwt.dev.jjs.ast.JPermutationDependentValue.traverse(JPermutationDependentValue.java:112)
        at com.google.gwt.dev.jjs.ast.JModVisitor.traverse(JModVisitor.java:361)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:273)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:265)
        at com.google.gwt.dev.jjs.ast.JVisitor.accept(JVisitor.java:118)
        at com.google.gwt.dev.jjs.ast.JBinaryOperation.traverse(JBinaryOperation.java:87)
        at com.google.gwt.dev.jjs.ast.JModVisitor.traverse(JModVisitor.java:361)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:273)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:265)
        at com.google.gwt.dev.jjs.ast.JVisitor.accept(JVisitor.java:118)
        at com.google.gwt.dev.jjs.ast.JBinaryOperation.traverse(JBinaryOperation.java:89)
        at com.google.gwt.dev.jjs.ast.JModVisitor.traverse(JModVisitor.java:361)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:273)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:265)
        at com.google.gwt.dev.jjs.ast.JVisitor.accept(JVisitor.java:118)
        at com.google.gwt.dev.jjs.ast.JExpressionStatement.traverse(JExpressionStatement.java:42)
        at com.google.gwt.dev.jjs.ast.JModVisitor$ListContext.traverse(JModVisitor.java:88)
        at com.google.gwt.dev.jjs.ast.JModVisitor.acceptWithInsertRemove(JModVisitor.java:331)
        at com.google.gwt.dev.jjs.ast.JBlock.traverse(JBlock.java:94)
        at com.google.gwt.dev.jjs.ast.JModVisitor.traverse(JModVisitor.java:361)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:273)
        at com.google.gwt.dev.jjs.ast.JVisitor.accept(JVisitor.java:139)
        at com.google.gwt.dev.jjs.ast.JVisitor.accept(JVisitor.java:135)
        at com.google.gwt.dev.jjs.ast.JMethodBody.traverse(JMethodBody.java:83)
        at com.google.gwt.dev.jjs.ast.JModVisitor.traverse(JModVisitor.java:361)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:273)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:265)
        at com.google.gwt.dev.jjs.ast.JMethod.visitChildren(JMethod.java:786)
        at com.google.gwt.dev.jjs.ast.JMethod.traverse(JMethod.java:778)
        at com.google.gwt.dev.jjs.ast.JModVisitor$ListContextImmutable.traverse(JModVisitor.java:169)
        at com.google.gwt.dev.jjs.ast.JModVisitor.acceptWithInsertRemoveImmutable(JModVisitor.java:336)
        at com.google.gwt.dev.jjs.ast.JClassType.traverse(JClassType.java:147)
        at com.google.gwt.dev.jjs.ast.JModVisitor.traverse(JModVisitor.java:361)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:273)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:265)
        at com.google.gwt.dev.jjs.ast.JProgram.visitModuleTypes(JProgram.java:1284)
        at com.google.gwt.dev.jjs.ast.JProgram.traverse(JProgram.java:1249)
        at com.google.gwt.dev.jjs.ast.JModVisitor.traverse(JModVisitor.java:361)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:273)
        at com.google.gwt.dev.jjs.ast.JModVisitor.accept(JModVisitor.java:265)
        at com.google.gwt.dev.jjs.impl.ResolvePermutationDependentValues.execImpl(ResolvePermutationDependentValues.java:168)
        at com.google.gwt.dev.jjs.impl.ResolvePermutationDependentValues.exec(ResolvePermutationDependentValues.java:118)
        at com.google.gwt.dev.jjs.JavaToJavaScriptCompiler.compilePermutation(JavaToJavaScriptCompiler.java:333)
        at com.google.gwt.dev.jjs.JavaToJavaScriptCompiler.compilePermutation(JavaToJavaScriptCompiler.java:272)
        at com.google.gwt.dev.CompilePerms.compile(CompilePerms.java:198)
        at com.google.gwt.dev.ThreadedPermutationWorkerFactory$ThreadedPermutationWorker.compile(ThreadedPermutationWorkerFactory.java:50)
        at com.google.gwt.dev.PermutationWorkerFactory$Manager$WorkerThread.run(PermutationWorkerFactory.java:74)
        at java.lang.Thread.run(Thread.java:750)
Caused by: java.lang.NullPointerException
        at com.google.gwt.thirdparty.guava.common.base.Preconditions.checkNotNull(Preconditions.java:212)
        at com.google.gwt.thirdparty.guava.common.base.Joiner.toString(Joiner.java:447)
        at com.google.gwt.thirdparty.guava.common.base.Joiner.appendTo(Joiner.java:110)
        at com.google.gwt.thirdparty.guava.common.base.Joiner.appendTo(Joiner.java:154)
        at com.google.gwt.thirdparty.guava.common.base.Joiner.join(Joiner.java:197)
        at com.google.gwt.thirdparty.guava.common.base.Joiner.join(Joiner.java:186)
        at com.google.gwt.dev.jjs.impl.ResolvePermutationDependentValues$ValueReplacer.propertyValueExpression(ResolvePermutationDependentValues.java:84)
        at com.google.gwt.dev.jjs.impl.ResolvePermutationDependentValues$ValueReplacer.endVisit(ResolvePermutationDependentValues.java:74)
        ... 48 more
               [ERROR] at SafeStylesHostedModeUtils.java(285): <source info not available>
                  com.google.gwt.dev.jjs.ast.JPermutationDependentValue
               [ERROR] at SafeStylesHostedModeUtils.java(285): <source info not available>
                  com.google.gwt.dev.jjs.ast.JPermutationDependentValue
               [ERROR] at SafeStylesHostedModeUtils.java(285): <source info not available>
                  com.google.gwt.dev.jjs.ast.JBinaryOperation
               [ERROR] at SafeStylesHostedModeUtils.java(285): <source info not available>
                  com.google.gwt.dev.jjs.ast.JBinaryOperation
               [ERROR] at SafeStylesHostedModeUtils.java(285): <source info not available>
                  com.google.gwt.dev.jjs.ast.JExpressionStatement
               [ERROR] at SafeStylesHostedModeUtils.java(284): <source info not available>
                  com.google.gwt.dev.jjs.ast.JBlock
               [ERROR] at SafeStylesHostedModeUtils.java(284): <source info not available>
                  com.google.gwt.dev.jjs.ast.JMethodBody
               [ERROR] at SafeStylesHostedModeUtils.java(284): org.gwtproject.safecss.shared.SafeStylesHostedModeUtils.setForceCheckValidStyleFromProperty()V
                  com.google.gwt.dev.jjs.ast.JMethod
               [ERROR] at SafeStylesHostedModeUtils.java(30): org.gwtproject.safecss.shared.SafeStylesHostedModeUtils (extends Object)
                  com.google.gwt.dev.jjs.ast.JClassType
               [ERROR] at Unknown(0): <JProgram>
                  com.google.gwt.dev.jjs.ast.JProgram

[niloc132]

Thanks for checking, at least we see the SafeStylesHostedModeUtils.setForceCheckValidStyleFromProperty, maybe we can figure out why that isn't giving us more specifics...

That method isnt JSNI or something, so it should have been possible to get sources:
https://github.com/gwtproject/gwt-safehtml/blob/99d2afbec0e035e37e5c9c8dfa49115ba31a7c14/gwt-safecss/src/main/java/org/gwtproject/safecss/shared/SafeStylesHostedModeUtils.java#L277-L286

GWT's UnifyAst.handleSystemGetProperty() created this as a replacement for the System.getProperty magic method.

It should probably also check "true".equals(...) instead of just != null to fix this and to handle an actual "false" value set deliberately.

That said, the method is never even called. Tests and prod must prune it before it gets a chance to be called, but I find it hard to believe that no one is using this in SDM (elemento, domino-ui, etc).

[zbynek]

Closing this in favor of @niloc132 's upcoming PR.