linter: null safety for functions, methods and properties for classes (…

…#1245)

docs/checkers_doc.md

@@ -4,7 +4,7 @@
 
 | Total checks | Checks enabled by default | Disabled checks by default | Autofixable checks |
 | ------------ | ------------------------- | -------------------------- | ------------------ |
-| 106           | 88                        | 18                         | 15                 |
+| 107           | 89                        | 18                         | 15                 |
 
 ## Table of contents
  - Enabled by default
@@ -60,6 +60,7 @@
    - [`newAbstract` checker](#newabstract-checker)
    - [`nonPublicInterfaceMember` checker](#nonpublicinterfacemember-checker)
    - [`notExplicitNullableParam` checker (autofixable)](#notexplicitnullableparam-checker)
+   - [`notNullSafety` checker](#notnullsafety-checker)
    - [`offBy1` checker (autofixable)](#offby1-checker)
    - [`oldStyleConstructor` checker](#oldstyleconstructor-checker)
    - [`paramClobber` checker](#paramclobber-checker)
@@ -1199,6 +1200,25 @@ function f(?string $str = null);
 <p><br></p>
 
 
+### `notNullSafety` checker
+
+#### Description
+
+Report not nullsafety call
+
+#### Non-compliant code:
+```php
+function f(A $klass);
+						f(null);
+```
+
+#### Compliant code:
+```php
+reported not safety call
+```
+<p><br></p>
+
+
 ### `offBy1` checker
 
 > Auto fix available

src/linter/block.go

@@ -1027,7 +1027,202 @@ func (b *blockWalker) handleIssetDimFetch(e *ir.ArrayDimFetchExpr) {
 	}
 }
 
+func nullSafetyRealParamForCheck(fn meta.FuncInfo, paramIndex int, haveVariadic bool) meta.FuncParam {
+	if haveVariadic && paramIndex >= len(fn.Params)-1 {
+		return fn.Params[len(fn.Params)-1]
+	}
+	return fn.Params[paramIndex]
+}
+
+func formatSlashesFuncName(fn meta.FuncInfo) string {
+	return strings.TrimPrefix(fn.Name, "\\")
+}
+
+func (b *blockWalker) checkNullSafetyCallArgsF(args []ir.Node, fn meta.FuncInfo) {
+	if fn.Params == nil || fn.Name == "" {
+		return
+	}
+	haveVariadic := fn.Flags&meta.FuncVariadic != 0
+
+	for i, arg := range args {
+		if arg == nil {
+			continue
+		}
+
+		// If there are more arguments than declared and function is not variadic, ignore extra arguments.
+		if !haveVariadic && i > len(fn.Params)-1 {
+			return
+		}
+
+		switch a := arg.(*ir.Argument).Expr.(type) {
+		case *ir.SimpleVar:
+			b.checkSimpleVarNullSafety(arg, fn, i, a, haveVariadic)
+		case *ir.ConstFetchExpr:
+			b.checkConstFetchNullSafety(arg, fn, i, a, haveVariadic)
+		case *ir.ArrayDimFetchExpr:
+			b.checkArrayDimFetchNullSafety(arg, fn, i, a, haveVariadic)
+		case *ir.ListExpr:
+			b.checkListExprNullSafety(arg, fn, i, a, haveVariadic)
+		case *ir.PropertyFetchExpr:
+			b.checkPropertyFetchNullSafety(a, fn, i, haveVariadic)
+		}
+	}
+}
+
+func (b *blockWalker) checkSimpleVarNullSafety(arg ir.Node, fn meta.FuncInfo, paramIndex int, variable *ir.SimpleVar, haveVariadic bool) {
+	varInfo, ok := b.ctx.sc.GetVar(variable)
+	if !ok {
+		return
+	}
+
+	param := nullSafetyRealParamForCheck(fn, paramIndex, haveVariadic)
+	if haveVariadic && paramIndex >= len(fn.Params)-1 {
+		// For variadic parameter check, if type is mixed then skip.
+		if types.IsTypeMixed(param.Typ) {
+			return
+		}
+	}
+	paramAllowsNull := types.IsTypeNullable(param.Typ)
+	varIsNullable := types.IsTypeNullable(varInfo.Type)
+	if varIsNullable && !paramAllowsNull {
+		b.report(arg, LevelWarning, "notNullSafety",
+			"not null safety call in function %s signature of param %s",
+			formatSlashesFuncName(fn), param.Name)
+	}
+}
+
+func (b *blockWalker) checkConstFetchNullSafety(arg ir.Node, fn meta.FuncInfo, paramIndex int, constExpr *ir.ConstFetchExpr, haveVariadic bool) {
+	constVal := constExpr.Constant.Value
+	isNull := constVal == "null"
+
+	param := nullSafetyRealParamForCheck(fn, paramIndex, haveVariadic)
+	if haveVariadic && paramIndex >= len(fn.Params)-1 {
+		if types.IsTypeMixed(param.Typ) {
+			return
+		}
+	}
+	paramAllowsNull := types.IsTypeNullable(param.Typ)
+	if isNull && !paramAllowsNull {
+		b.report(arg, LevelWarning, "notNullSafety",
+			"null passed to non-nullable parameter %s in function %s",
+			param.Name, formatSlashesFuncName(fn))
+	}
+}
+
+func (b *blockWalker) checkArrayDimFetchNullSafety(arg ir.Node, fn meta.FuncInfo, paramIndex int, arrayExpr *ir.ArrayDimFetchExpr, haveVariadic bool) {
+	baseVar, ok := arrayExpr.Variable.(*ir.SimpleVar)
+	if !ok {
+		return
+	}
+
+	varInfo, found := b.ctx.sc.GetVar(baseVar)
+	if !found {
+		return
+	}
+
+	param := nullSafetyRealParamForCheck(fn, paramIndex, haveVariadic)
+	if haveVariadic && paramIndex >= len(fn.Params)-1 {
+		if types.IsTypeMixed(param.Typ) {
+			return
+		}
+	}
+	paramAllowsNull := types.IsTypeNullable(param.Typ)
+	if types.IsTypeNullable(varInfo.Type) && !paramAllowsNull {
+		b.report(arg, LevelWarning, "notNullSafety",
+			"potential null array access in parameter %s of function %s",
+			param.Name, formatSlashesFuncName(fn))
+	}
+}
+
+func (b *blockWalker) checkListExprNullSafety(arg ir.Node, fn meta.FuncInfo, paramIndex int, listExpr *ir.ListExpr, haveVariadic bool) {
+	for _, item := range listExpr.Items {
+		if item == nil {
+			continue
+		}
+
+		if item.Key != nil {
+			b.checkNullSafetyCallArgsF([]ir.Node{item.Key}, fn)
+		}
+
+		if item.Val != nil {
+			param := nullSafetyRealParamForCheck(fn, paramIndex, haveVariadic)
+			if simpleVar, ok := item.Val.(*ir.SimpleVar); ok {
+				varInfo, found := b.ctx.sc.GetVar(simpleVar)
+				if found && types.IsTypeNullable(varInfo.Type) && !types.IsTypeNullable(param.Typ) {
+					b.report(arg, LevelWarning, "notNullSafety",
+						"potential null value in list assignment for param %s in function %s",
+						param.Name, formatSlashesFuncName(fn))
+				}
+			}
+			b.checkNullSafetyCallArgsF([]ir.Node{item.Val}, fn)
+		}
+	}
+}
+
+func (b *blockWalker) getPropertyComputedType(expr *ir.PropertyFetchExpr) (meta.ClassInfo, types.Map) {
+	baseCall, ok := expr.Variable.(*ir.SimpleVar)
+	if !ok {
+		return meta.ClassInfo{}, types.Map{}
+	}
+
+	varInfo, ok := b.ctx.sc.GetVar(baseCall)
+	if !ok {
+		return meta.ClassInfo{}, types.Map{}
+	}
+
+	classInfo, ok := b.r.ctx.st.Info.GetClass(varInfo.Type.String())
+	if !ok {
+		return meta.ClassInfo{}, types.Map{}
+	}
+
+	property, ok := expr.Property.(*ir.Identifier)
+	if !ok {
+		return meta.ClassInfo{}, types.Map{}
+	}
+
+	propertyInfoFromClass := classInfo.Properties[property.Value]
+	return classInfo, propertyInfoFromClass.Typ
+}
+
+func (b *blockWalker) checkPropertyFetchNullSafety(expr *ir.PropertyFetchExpr, fn meta.FuncInfo, paramIndex int, haveVariadic bool) {
+	// Recursively check the left part of the chain if it is also a property fetch.
+	if nested, ok := expr.Variable.(*ir.PropertyFetchExpr); ok {
+		b.checkPropertyFetchNullSafety(nested, fn, paramIndex, haveVariadic)
+	}
+
+	classInfo, propType := b.getPropertyComputedType(expr)
+	if classInfo.Name == "" || propType.Empty() {
+		return
+	}
+
+	prp, ok := expr.Property.(*ir.Identifier)
+	if !ok {
+		return
+	}
+
+	isPrpNullable := types.IsTypeNullable(propType)
+	param := nullSafetyRealParamForCheck(fn, paramIndex, haveVariadic)
+	if haveVariadic && paramIndex >= len(fn.Params)-1 {
+		if types.IsTypeMixed(param.Typ) {
+			return
+		}
+		paramAllowsNull := types.IsTypeNullable(param.Typ)
+		if isPrpNullable && !paramAllowsNull {
+			b.report(expr, LevelWarning, "notNullSafety",
+				"potential null dereference when accessing property '%s'", prp.Value)
+		}
+		return
+	}
+
+	paramAllowsNull := types.IsTypeNullable(param.Typ)
+	if isPrpNullable && !paramAllowsNull {
+		b.report(expr, LevelWarning, "notNullSafety",
+			"potential null dereference when accessing property '%s'", prp.Value)
+	}
+}
 func (b *blockWalker) handleCallArgs(args []ir.Node, fn meta.FuncInfo) {
+	b.checkNullSafetyCallArgsF(args, fn)
+
 	for i, arg := range args {
 		if i >= len(fn.Params) {
 			arg.Walk(b)
@@ -1388,13 +1583,19 @@ func (b *blockWalker) enterClosure(fun *ir.ClosureExpr, haveThis bool, thisType
 		b.r.meta.Functions = meta.NewFunctionsMap()
 	}
 
+	var funcFlags meta.FuncFlags
+
+	if params.isVariadic {
+		funcFlags |= meta.FuncVariadic
+	}
+
 	b.r.meta.Functions.Set(name, meta.FuncInfo{
 		Params:          params.params,
 		Name:            name,
 		Pos:             b.r.getElementPos(fun),
 		Typ:             returnTypes.Immutable(),
 		MinParamsCnt:    params.minParamsCount,
-		Flags:           0,
+		Flags:           funcFlags,
 		ExitFlags:       exitFlags,
 		DeprecationInfo: doc.Deprecation,
 	})

src/linter/cache.go

@@ -17,42 +17,43 @@ import (
 //
 // Version log:
 //
-//		27 - added Static field to meta.FuncInfo
-//		28 - array type parsed as mixed[]
-//		29 - updated type inference for ClassConstFetch
-//		30 - resolve ClassConstFetch to a wrapped type string
-//		31 - fixed plus operator type inference for arrays
-//		32 - replaced Static:bool with Flags:uint8 in meta.FuncInfo
-//		33 - support parsing of array<k,v> and list<type>
-//		34 - support parsing of ?ClassName as "ClassName|null"
-//		35 - added Flags:uint8 to meta.ClassInfo
-//		36 - added FuncAbstract bit to FuncFlags
-//		     added FuncFinal bit to FuncFlags
-//		     added ClassFinal bit to ClassFlags
-//		     FuncInfo now stores original function name
-//		     ClassInfo now stores original class name
-//		37 - added ClassShape bit to ClassFlags
-//		     changed meta.scopeVar bool fields representation
-//		38 - replaced TypesMap.immutable:bool with flags:uint8.
-//		     added mapPrecise flag to mark precise type maps.
-//		39 - added new field Value in ConstantInfo
-//		40 - changed string const value storage (no quotes)
-//		41 - const-folding affected const definition values
-//		42 - bool-typed consts are now stored in meta info
-//		43 - define'd const values stored in cache
-//		44 - rename ConstantInfo => ConstInfo
-//		45 - added Mixins field to meta.ClassInfo
-//		46 - changed the way of inferring the return type of functions and methods
-//		47 - forced cache version invalidation due to the #921
-//		48 - renamed meta.TypesMap to types.Map; this affects gob encoding
-//		49 - for shape, names are now generated using the keys that make up this shape
-//		50 - added Flags field for meta.PropertyInfo
-//		51 - added anonymous classes
-//		52 - renamed all PhpDoc and Phpdoc with PHPDoc
-//		53 - added DeprecationInfo for functions and methods and support for some attributes
-//		54 - forced cache version invalidation due to the #1165
-//	 55 - updated go version 1.16 -> 1.21
-const cacheVersion = 55
+//			27 - added Static field to meta.FuncInfo
+//			28 - array type parsed as mixed[]
+//			29 - updated type inference for ClassConstFetch
+//			30 - resolve ClassConstFetch to a wrapped type string
+//			31 - fixed plus operator type inference for arrays
+//			32 - replaced Static:bool with Flags:uint8 in meta.FuncInfo
+//			33 - support parsing of array<k,v> and list<type>
+//			34 - support parsing of ?ClassName as "ClassName|null"
+//			35 - added Flags:uint8 to meta.ClassInfo
+//			36 - added FuncAbstract bit to FuncFlags
+//			     added FuncFinal bit to FuncFlags
+//			     added ClassFinal bit to ClassFlags
+//			     FuncInfo now stores original function name
+//			     ClassInfo now stores original class name
+//			37 - added ClassShape bit to ClassFlags
+//			     changed meta.scopeVar bool fields representation
+//			38 - replaced TypesMap.immutable:bool with flags:uint8.
+//			     added mapPrecise flag to mark precise type maps.
+//			39 - added new field Value in ConstantInfo
+//			40 - changed string const value storage (no quotes)
+//			41 - const-folding affected const definition values
+//			42 - bool-typed consts are now stored in meta info
+//			43 - define'd const values stored in cache
+//			44 - rename ConstantInfo => ConstInfo
+//			45 - added Mixins field to meta.ClassInfo
+//			46 - changed the way of inferring the return type of functions and methods
+//			47 - forced cache version invalidation due to the #921
+//			48 - renamed meta.TypesMap to types.Map; this affects gob encoding
+//			49 - for shape, names are now generated using the keys that make up this shape
+//			50 - added Flags field for meta.PropertyInfo
+//			51 - added anonymous classes
+//			52 - renamed all PhpDoc and Phpdoc with PHPDoc
+//			53 - added DeprecationInfo for functions and methods and support for some attributes
+//			54 - forced cache version invalidation due to the #1165
+//		 	55 - updated go version 1.16 -> 1.21
+//	     56 - added isVariadic to meta.FuncInfo
+const cacheVersion = 56
 
 var (
 	errWrongVersion = errors.New("Wrong cache version")

src/linter/report.go

@@ -25,6 +25,16 @@ func addBuiltinCheckers(reg *CheckersRegistry) {
 			After:    `$s = strip_tags($s, '<br>')`,
 		},
 
+		{
+			Name:     "notNullSafety",
+			Default:  true,
+			Quickfix: false,
+			Comment:  "Report not nullsafety call",
+			Before: `function f(A $klass);
+						f(null);`,
+			After: `reported not safety call`,
+		},
+
 		{
 			Name:     "notExplicitNullableParam",
 			Default:  true,