fix: G602 support for nested conditionals with bounds check (#1201)

* Recursive fix

* Add some more test cases

* Fix formatting

* Add depth check

analyzers/slice_bounds.go

@@ -118,32 +118,45 @@ func runSliceBounds(pass *analysis.Pass) (interface{}, error) {
 			if i == 1 {
 				bound = invBound(bound)
 			}
-			for _, instr := range block.Instrs {
-				if _, ok := issues[instr]; ok {
-					switch bound {
-					case lowerUnbounded:
-						break
-					case upperUnbounded, unbounded:
-						delete(issues, instr)
-					case upperBounded:
-						switch tinstr := instr.(type) {
-						case *ssa.Slice:
-							lower, upper := extractSliceBounds(tinstr)
-							if isSliceInsideBounds(0, value, lower, upper) {
-								delete(issues, instr)
-							}
-						case *ssa.IndexAddr:
-							indexValue, err := extractIntValue(tinstr.Index.String())
-							if err != nil {
-								break
-							}
-							if isSliceIndexInsideBounds(0, value, indexValue) {
-								delete(issues, instr)
+			var processBlock func(block *ssa.BasicBlock, depth int)
+			processBlock = func(block *ssa.BasicBlock, depth int) {
+				if depth == maxDepth {
+					return
+				}
+				depth++
+				for _, instr := range block.Instrs {
+					if _, ok := issues[instr]; ok {
+						switch bound {
+						case lowerUnbounded:
+							break
+						case upperUnbounded, unbounded:
+							delete(issues, instr)
+						case upperBounded:
+							switch tinstr := instr.(type) {
+							case *ssa.Slice:
+								lower, upper := extractSliceBounds(tinstr)
+								if isSliceInsideBounds(0, value, lower, upper) {
+									delete(issues, instr)
+								}
+							case *ssa.IndexAddr:
+								indexValue, err := extractIntValue(tinstr.Index.String())
+								if err != nil {
+									break
+								}
+								if isSliceIndexInsideBounds(0, value, indexValue) {
+									delete(issues, instr)
+								}
 							}
 						}
+					} else if nestedIfInstr, ok := instr.(*ssa.If); ok {
+						for _, nestedBlock := range nestedIfInstr.Block().Succs {
+							processBlock(nestedBlock, depth)
+						}
 					}
 				}
 			}
+
+			processBlock(block, 0)
 		}
 	}
 

testutils/g602_samples.go

@@ -195,13 +195,13 @@ package main
 import "fmt"
 
 func main() {
-  testMap := make(map[string]any, 0)
-  testMap["test1"] = map[string]interface{}{
-    "test2": map[string]interface{}{
-      "value": 0,
-    },
-  }
-  fmt.Println(testMap)
+	testMap := make(map[string]any, 0)
+	testMap["test1"] = map[string]interface{}{
+	"test2": map[string]interface{}{
+			"value": 0,
+		},
+	}
+	fmt.Println(testMap)
 }
 `}, 0, gosec.NewConfig()},
 	{[]string{`
@@ -210,17 +210,104 @@ package main
 import "fmt"
 
 func main() {
-  s := make([]byte, 0)
-  if len(s) > 0 {
-    fmt.Println(s[0])
-  }
+	s := make([]byte, 0)
+	if len(s) > 0 {
+		fmt.Println(s[0])
+	}
+}
+`}, 0, gosec.NewConfig()},
+	{[]string{`
+package main
+
+import "fmt"
+
+func main() {
+	s := make([]byte, 0)
+	if len(s) > 0 {
+		switch s[0] {
+		case 0:
+			fmt.Println("zero")
+			return
+		default:
+			fmt.Println(s[0])
+			return
+		}
+	}
 }
 `}, 0, gosec.NewConfig()},
 	{[]string{`
 package main
 
 import "fmt"
 
+func main() {
+	s := make([]byte, 0)
+	if len(s) > 0 {
+		switch s[0] {
+		case 0:
+			b := true
+			if b == true {
+				// Should work for many-levels of nesting when the condition is not on the target slice
+				fmt.Println(s[0])
+			}
+			return
+		default:
+			fmt.Println(s[0])
+			return
+		}
+	}
+}
+`}, 0, gosec.NewConfig()},
+	{[]string{`
+package main
+
+import "fmt"
+
+func main() {
+	s := make([]byte, 0)
+	if len(s) > 0 {
+		if len(s) > 1 {
+			fmt.Println(s[1])
+		}
+		fmt.Println(s[0])
+	}
+}
+`}, 0, gosec.NewConfig()},
+	{[]string{`
+package main
+
+import "fmt"
+
+func main() {
+s := make([]byte, 2)
+fmt.Println(s[1])
+s = make([]byte, 0)
+fmt.Println(s[1])
+}
+`}, 1, gosec.NewConfig()},
+	{[]string{`
+package main
+
+import "fmt"
+
+func main() {
+	s := make([]byte, 0)
+	if len(s) > 0 {
+		if len(s) > 4 {
+			fmt.Println(s[3])
+		} else {
+			// Should error
+			fmt.Println(s[2])
+		}
+		fmt.Println(s[0])
+	}
+}
+`}, 1, gosec.NewConfig()},
+	{[]string{`
+package main
+
+import "fmt"
+
 func main() {
 	s := make([]byte, 0)
 	if len(s) > 0 {
@@ -249,5 +336,6 @@ func main() {
 		fmt.Println(s[i])
 	}
 }
+
 `}, 0, gosec.NewConfig()},
 }