Staticcheck 2017.2 release notes
The 2017.2 release of the staticcheck suite of tools focuses on reducing friction – fewer false positives, more tools for suppressing unwanted output, and JSON output for easier integration with other tools.
Linter directives for ignoring problems
In the past, the only ways to ignore reported problems was by using
-ignore flag. This led to overreaching ignore rules
which weren’t maintained regularly. Now,
//lint:file-ignore comments can be used to ignore
problems, either on specific lines or file-wide. A full description of
these directives, their syntax and their behavior can be found
in the documentation.
A related change adds the
-show-ignored command line
flag, which outputs problems that would otherwise be ignored by
directives. This is primarily of use with the JSON output format,
for custom front ends.
All staticcheck tools now support multiple output formats, selectable
Currently, two formats are supported. The first format is
text, which is the default and uses the existing terminal
output format. The other is
json, which emits JSON. The
output is a stream of objects, allowing for a future streaming output
mode. Each object uses the following example schema:
"message": "this value of err is never used",
Control over the exit code of megacheck
Megacheck, the tool for running multiple checkers at once, now has
per checker flags for controlling the overall exit code. Previously,
megacheck would exit non-zero if any checker found a problem. Now it
is possible to configure for each checker whether it should cause a
non-zero exit, by using the
flags. This flag defaults to false for gosimple and to true for
the other checkers.
Changes to checks
NoCopy in unused
The unused tool now understands
NoCopy sentinel types. The
NoCopy type, which is canonically a struct with no fields and only a
Lock method, can be used to mark structs as not safe
for copying. By declaring a field of this type, go vet will complain
when it sees instances of the struct being copied.
In the past, unused marked these fields as unused, now it ignores them.
Detection of deprecated identifiers
correctly identifies deprecated methods, in addition to fields and
package-level objects. Additionally, staticcheck now keeps track of
when each identifier in the Go standard library was deprecated, so
-go <version> can correctly
ignore deprecation warnings that don’t apply to the targeted Go
- SA4017 no longer reports pure functions that are stubs – functions that immediately panic or return a constant.
- SA5007 no longer flags infinite recursion when the function call is spawned as a new goroutine.
- SA6002 now recognizes that
unsafe.Pointeris a pointer type.
- S1005 no longer suggests
for rangewhen targeting a version older than Go 1.4.
- S1026 has been removed. In some rare instances, copying a string is necessary, and all common ways of doing this were incorrectly flagged by the check.
-ignoreflag now supports ignoring checks in all packages, by using
*as the path.
//linedirectives are now being ignored when reporting problems. That is, problems will always be reported for the actual position in the Go files they occur.
- From now on, only the first compilation error encountered will be reported. The tools expect to be run on valid Go code and there was little (if any) value in reporting all compilation errors encountered, especially because simple errors can lead to many follow-up errors.
Staticcheck 2017.2.1 Release Notes
The 2017.2.1 release of the staticcheck suite of tools is the first bug fix release, fixing one bug.
Staticcheck 2017.2 made the detection of deprecated objects Go-version aware. Unfortunately, this only worked correctly for fields and methods, but not package-level objects. This release fixes that.
Staticcheck 2017.2.2 Release Notes
The 2017.2.2 release of the staticcheck suite of tools is the second bug fix release, fixing several bugs.
- unused: correctly apply the NoCopy exemption when using the
- keyify: support external test packages (
- staticcheck: disable SA4005 – the check, in its current form, is prone to false positives and will be reimplemented in a future release.