go/analysis/passes/ctrlflow: an Analyzer that builds CFGs

The ctrlflow Analyzer builds a control-flow graph (see
golang.org/x/tools/go/cfg) for each named and unnamed function in the
package.

It computes for each function whether it can never return, either
because the function is an intrinsic that stops the thread (e.g.
os.Exit), or because control never reaches a return statement, or
because the function inevitably calls another function that never
returns.  For each such function it exports a noReturn fact.

This change also:
- adds 'inspect', another Analyzer that builds an optimized AST
  traversal table for use by nearly every other Analyzer.
- changes analysistest.Run to return the analysis result to enable
  further testing.
  (This required changing it to analyze one package at a time,
  which is no less efficient, and is the typical case.)

Change-Id: I877e2b2363a365a9976aa9c2719ad3fba4df2634
Reviewed-on: https://go-review.googlesource.com/c/139478
Reviewed-by: Michael Matloob <matloob@golang.org>
8 files changed
tree: c4cbaa35a640321ec147ea276acb67797521d038
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. imports/
  9. internal/
  10. playground/
  11. present/
  12. refactor/
  13. third_party/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. LICENSE
  21. PATENTS
  22. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.