// Copyright 2010 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. /* Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string. Vet uses heuristics that do not guarantee all reports are genuine problems, but it can find errors not caught by the compilers. Usage: go tool vet [flag] [file.go ...] go tool vet [flag] [directory ...] # Scan all .go files under directory, recursively Its exit code is 2 for erroneous invocation of the tool, 1 if a problem was reported, and 0 otherwise. Note that the tool does not check every possible problem and depends on unreliable heuristics so it should be used as guidance only, not as a firm indicator of program correctness. By default all checks are performed, but if explicit flags are provided, only those identified by the flags are performed. Available checks: 1. Printf family Flag -printf Suspicious calls to functions in the Printf family, including any functions with these names: Print Printf Println Fprint Fprintf Fprintln Sprint Sprintf Sprintln Error Errorf Fatal Fatalf Panic Panicf Panicln If the function name ends with an 'f', the function is assumed to take a format descriptor string in the manner of fmt.Printf. If not, vet complains about arguments that look like format descriptor strings. It also checks for errors such as using a Writer as the first argument of Printf. 2. Methods Flag -methods Non-standard signatures for methods with familiar names, including: Format GobEncode GobDecode MarshalJSON MarshalXML Peek ReadByte ReadFrom ReadRune Scan Seek UnmarshalJSON UnreadByte UnreadRune WriteByte WriteTo 3. Struct tags Flag -structtags Struct tags that do not follow the format understood by reflect.StructTag.Get. 4. Unkeyed composite literals Flag -composites Composite struct literals that do not use the field-keyed syntax. 5. Assembly declarations Flag -asmdecl Mismatches between assembly files and Go function declarations. 6. Useless assignments Flag -assign Check for useless assignments. 7. Atomic mistakes Flag -atomic Common mistaken usages of the sync/atomic package. 8. Build tags Flag -buildtags Badly formed or misplaced +build tags. 9. Copying locks Flag -copylocks Locks that are erroneously passed by value. 10. Nil function comparison Flag -nilfunc Comparisons between functions and nil. 11. Range loop variables Flag -rangeloops Incorrect uses of range loop variables in closures. 12. Unreachable code Flag -unreachable Unreachable code. 13. Shadowed variables Flag -shadow=false (experimental; must be set explicitly) Variables that may have been unintentionally shadowed. Other flags These flags configure the behavior of vet: -all (default true) Check everything; disabled if any explicit check is requested. -v Verbose mode -printfuncs A comma-separated list of print-like functions to supplement the standard list. Each entry is in the form Name:N where N is the zero-based argument position of the first argument involved in the print: either the format or the first print argument for non-formatted prints. For example, if you have Warn and Warnf functions that take an io.Writer as their first argument, like Fprintf, -printfuncs=Warn:1,Warnf:1 -shadowstrict Whether to be strict about shadowing; can be noisy. -test For testing only: sets -all and -shadow. */ package main