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path: root/tools/nogo/nogo.go
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2021-09-30Skip analysis of standard library packages using genericsMichael Pratt
The upstream analysis packages we depend on do not yet support analysis of code using Go 1.18 type parameter features, making analysis of the Go tip standard library choke and crash. Skip these packages for now. PiperOrigin-RevId: 400030256
2021-07-01Mix checklocks and atomic analyzers.Adin Scannell
This change makes the checklocks analyzer considerable more powerful, adding: * The ability to traverse complex structures, e.g. to have multiple nested fields as part of the annotation. * The ability to resolve simple anonymous functions and closures, and perform lock analysis across these invocations. This does not apply to closures that are passed elsewhere, since it is not possible to know the context in which they might be invoked. * The ability to annotate return values in addition to receivers and other parameters, with the same complex structures noted above. * Ignoring locking semantics for "fresh" objects, i.e. objects that are allocated in the local frame (typically a new-style function). * Sanity checking of locking state across block transitions and returns, to ensure that no unexpected locks are held. Note that initially, most of these findings are excluded by a comprehensive nogo.yaml. The findings that are included are fundamental lock violations. The changes here should be relatively low risk, minor refactorings to either include necessary annotations to simplify the code structure (in general removing closures in favor of methods) so that the analyzer can be easily track the lock state. This change additional includes two changes to nogo itself: * Sanity checking of all types to ensure that the binary and ast-derived types have a consistent objectpath, to prevent the bug above from occurring silently (and causing much confusion). This also requires a trick in order to ensure that serialized facts are consumable downstream. This can be removed with https://go-review.googlesource.com/c/tools/+/331789 merged. * A minor refactoring to isolation the objdump settings in its own package. This was originally used to implement the sanity check above, but this information is now being passed another way. The minor refactor is preserved however, since it cleans up the code slightly and is minimal risk. PiperOrigin-RevId: 382613300
2021-04-26nogo: enable bazel workers and other optimizations.Adin Scannell
This is a suite of changes intended to dramatically speed up nogo speed. First, there are minor changes that help efficiency significantly. * Gob-based encoding is used internally, and JSON only used for the final set of findings. This is done to preserve the existing format (which is consumed by external tooling), and to facilitate manual debugging. * Unnecessary regex compilation is elided in the configuration, and care is taken for merges to prevent redundant entries. I'm not sure quite sure how, but it turns out that this was consumed a significant amount of time, presumably compiling the same regexes over and over again. Second, this change enables bazel workers for nogo analyzers. Workers enable persistent processes instead of creating and tearing down a sandbox every invocation. A library is introduced to abstraction these details, and allow the tools to still be written using standard flags, etc. The key here is that these binaries and the core of nogo become aware of caches with worker.Cache. This allows us to save significant time loading the same set of files and findings over and over again. These caches are keyed by the digests that are provided by bazel, and are capped in overall size. Note that the worker package attempts to capture output during each run, but tools are no longer permitted to write to stdout. This necessitated dropping some spurious output from checklocks. PiperOrigin-RevId: 370505732
2021-04-23Improve nogo action cache-ability.Adin Scannell
Presently, the standard library facts are not serialized in a deterministic order. This means that they have the possibility to change on each iteration, requiring a large scale re-analysis of all downstream actions, which includes all packages. Improve cache-ability of nogo actions by improving the determinism of the both facts and findings. Internally, default facts should be serialized as a sorted list for this reason already. PiperOrigin-RevId: 370188259
2020-10-26Add nogo configuration.Adin Scannell
This splits the nogo rules into a separate configuration yaml file, and allows for multiple files to be provided. Because attrs cannot be passed down to aspects, this required that all findings are propagated up the aspect Provider. This doesn't mean that any extra work must be done, just that this information must be carried through the graph, and some additional starlark complexity is required. PiperOrigin-RevId: 339076357
2020-10-19Remove legacy bazel configurations.Adin Scannell
Using the newer bazel rules necessitates a transition from proto1 to proto2. In order to resolve the incompatibility between proto2 and gogoproto, the cri runtimeoptions proto must be vendored. Further, some of the semantics of bazel caching changed during the transition. It is now necessary to: - Ensure that :gopath depends only on pure library targets, as the propagation of go_binary build attributes (pure, static) will affected the generated files (though content remains the same, there are conflicts with respect to the gopath). - Update bazel.mk to include the possibility of binaries in the bazel-out directory, as it will now put runsc and others there. This required some refinements to the mechanism of extracting paths, since some the existing regex resulted in false positives. - Change nogo rules to prevent escape generation on binary targets. For some reason, the newer version of bazel attempted to run the nogo analysis on the binary targets, which fails due to the fact that objdump does not work on the final binary. This must be due to a change in the semantics of aspects in bazel3. PiperOrigin-RevId: 337958324
2020-10-16Cache errors when processing stdlib with nogo.Adin Scannell
PiperOrigin-RevId: 337515664
2020-09-11Make nogo more robust to variety of stdlib layouts.Michael Pratt
PiperOrigin-RevId: 331206424
2020-08-31Change nogo failures to test failures, instead of build failures.Adin Scannell
PiperOrigin-RevId: 329408633
2020-08-26Support stdlib analyzers with nogo.Adin Scannell
This immediately revealed an escape analysis violation (!), where the sync.Map was being used in a context that escapes were not allowed. This is a relatively minor fix and is included. PiperOrigin-RevId: 328611237
2020-07-23Internal changeMichael Pratt
PiperOrigin-RevId: 322788791
2020-07-13Merge pull request #2672 from amscanne:shim-integratedgVisor bot
PiperOrigin-RevId: 321053634
2020-04-20Add internal nogo analysis & checkescape tool.Adin Scannell
See tools/nogo/README.md. The checkescape tool is able to perform recursive escape analysis, using the actual generated binary to confirm the results produced by the compiler itself. As an initial use case, this replaces the manual escape analysis tests used for go_marshal, and validates that the CopyIn and CopyOut paths will not require any allocation or stack splits. Updates #2243 PiperOrigin-RevId: 307532986