oracle / oracle/graalpython

[Bug]: NullPointerException with top-level `async with`

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bug
Dominant language
Python
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Merged PRs (30d)
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Description

Describe the bug

GraalPy crashes when running this fuzzed code:

async with _:
    pass
Operating system

Linux

CPU architecture

x86_64

GraalPy version

GraalPy 3.13.14 (Oracle GraalVM Native 25.3.4.1)

JDK version

No response

Context configuration

No response

Steps to reproduce

Snippet listed above

Expected behavior

No crash

Stack trace
java.lang.NullPointerException: Stack trace is imprecise, the top frames are missing and/or have wrong line numbers. To get precise stack traces, build the image with option -H:-ReduceImplicitExceptionStackTraceInformation
	at org.graalvm.py/com.oracle.graal.python.compiler.ParserCallbacksImpl.raiseSyntaxError(ParserCallbacksImpl.java:126)
	at org.graalvm.py/com.oracle.graal.python.compiler.ParserCallbacksImpl.raiseSyntaxError(ParserCallbacksImpl.java:122)
	at org.graalvm.py/com.oracle.graal.python.compiler.ParserCallbacksImpl.onError(ParserCallbacksImpl.java:118)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler$StatementCompiler.visit(RootNodeCompiler.java:3953)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler$StatementCompiler.visit(RootNodeCompiler.java:2001)
	at org.graalvm.py/com.oracle.graal.python.pegparser.sst.StmtTy$AsyncWith.accept(StmtTy.java:381)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler.visitModuleBody(RootNodeCompiler.java:1090)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler.lambda$visit$0(RootNodeCompiler.java:1007)
	at org.graalvm.py/com.oracle.graal.python.nodes.bytecode_dsl.PBytecodeDSLRootNodeGen$Bytecode.create(PBytecodeDSLRootNodeGen.java:4988)
	at org.graalvm.py/com.oracle.graal.python.nodes.bytecode_dsl.PBytecodeDSLRootNodeGen.create(PBytecodeDSLRootNodeGen.java:3790)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler.compileRootNode(RootNodeCompiler.java:530)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler.visit(RootNodeCompiler.java:1005)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler.visit(RootNodeCompiler.java:186)
	at org.graalvm.py/com.oracle.graal.python.pegparser.sst.ModTy$Module.accept(ModTy.java:68)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.RootNodeCompiler.compile(RootNodeCompiler.java:755)
	at org.graalvm.py/com.oracle.graal.python.compiler.bytecode_dsl.BytecodeDSLCompiler.compile(BytecodeDSLCompiler.java:86)
	at org.graalvm.py/com.oracle.graal.python.PythonLanguage.compileForBytecodeDSLInterpreter(PythonLanguage.java:661)
	at org.graalvm.py/com.oracle.graal.python.PythonLanguage.compileModule(PythonLanguage.java:633)
	at org.graalvm.py/com.oracle.graal.python.PythonLanguage.parse(PythonLanguage.java:601)
	at org.graalvm.py/com.oracle.graal.python.PythonLanguage.parse(PythonLanguage.java:588)
	at org.graalvm.py/com.oracle.graal.python.PythonLanguage.parse(PythonLanguage.java:574)
[...snip...]
Additional context

No response

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the top-level async with _: snippet on Linux with GraalPy 3.13.14, then trace the failure through ParserCallbacksImpl.raiseSyntaxError and RootNodeCompiler's statement visitor. Done means the snippet no longer crashes with a NullPointerException and produces the expected non-crashing behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
java, python
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Active
Clarity
Clearly specified
Newbie friendliness
68/100

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