Cover is a program for analyzing the coverage profiles generated by 'go test -coverprofile=cover.out'.
Cover is also used by 'go test -cover' to rewrite the source code with annotations to track which parts of each function are executed. It operates on one Go source file at a time, computing approximate basic block information by studying the source. It is thus more portable than binary-rewriting coverage tools, but also a little less capable. For instance, it does not probe inside && and || expressions, and can be mildly confused by single statements with multiple function literals.
For usage information, please see:
go help testflag go tool cover -help
No longer maintained:
For Go releases 1.5 and later, this tool lives in the standard repository. The code here is not maintained.