87aae77943
Fix #324, relates #314 1. Update gocritic to the latest version 2. Use proper gocritic checkers repo, old repo was archived 3. Get enabled by default gocritic checks in sync with go-critic: don't enable performance, experimental and opinionated checks by default 4. Support of `enabled-tags` options for gocritic 5. Enable almost all gocritic checks for the project 6. Make rich debugging for gocritic 7. Meticulously validate gocritic checks config
87 lines
2.2 KiB
Go
87 lines
2.2 KiB
Go
package lintutil
|
|
|
|
import (
|
|
"go/ast"
|
|
"go/token"
|
|
"go/types"
|
|
|
|
"github.com/go-toolsmith/astequal"
|
|
"github.com/go-toolsmith/astp"
|
|
"github.com/go-toolsmith/typep"
|
|
)
|
|
|
|
// Different utilities to make simple analysis over typed ast values flow.
|
|
//
|
|
// It's primitive and can't replace SSA, but the bright side is that
|
|
// it does not require building an additional IR eagerly.
|
|
// Expected to be used sparingly inside a few checkers.
|
|
//
|
|
// If proven really useful, can be moved to go-toolsmith library.
|
|
|
|
// IsImmutable reports whether n can be midified through any operation.
|
|
func IsImmutable(info *types.Info, n ast.Expr) bool {
|
|
if astp.IsBasicLit(n) {
|
|
return true
|
|
}
|
|
tv, ok := info.Types[n]
|
|
return ok && !tv.Assignable() && !tv.Addressable()
|
|
}
|
|
|
|
// CouldBeMutated reports whether dst can be modified inside body.
|
|
//
|
|
// Note that it does not take already existing pointers to dst.
|
|
// An example of safe and correct usage is checking of something
|
|
// that was just defined, so the dst is a result of that definition.
|
|
func CouldBeMutated(info *types.Info, body ast.Node, dst ast.Expr) bool {
|
|
if IsImmutable(info, dst) { // Fast path.
|
|
return false
|
|
}
|
|
|
|
// We don't track pass-by-value.
|
|
// If it's already a pointer, passing it by value
|
|
// means that there can be a potential indirect modification.
|
|
//
|
|
// It's possible to be less conservative here and find at least
|
|
// one such value pass before giving up.
|
|
if typep.IsPointer(info.TypeOf(dst)) {
|
|
return true
|
|
}
|
|
|
|
var isDst func(x ast.Expr) bool
|
|
if dst, ok := dst.(*ast.Ident); ok {
|
|
// Identifier can be shadowed,
|
|
// so we need to check the object as well.
|
|
obj := info.ObjectOf(dst)
|
|
if obj == nil {
|
|
return true // Being conservative
|
|
}
|
|
isDst = func(x ast.Expr) bool {
|
|
id, ok := x.(*ast.Ident)
|
|
return ok && id.Name == dst.Name && info.ObjectOf(id) == obj
|
|
}
|
|
} else {
|
|
isDst = func(x ast.Expr) bool {
|
|
return astequal.Expr(dst, x)
|
|
}
|
|
}
|
|
|
|
return ContainsNode(body, func(n ast.Node) bool {
|
|
switch n := n.(type) {
|
|
case *ast.UnaryExpr:
|
|
if n.Op == token.AND && isDst(n.X) {
|
|
return true // Address taken
|
|
}
|
|
case *ast.AssignStmt:
|
|
for _, lhs := range n.Lhs {
|
|
if isDst(lhs) {
|
|
return true
|
|
}
|
|
}
|
|
case *ast.IncDecStmt:
|
|
// Incremented or decremented.
|
|
return isDst(n.X)
|
|
}
|
|
return false
|
|
})
|
|
}
|