chore: protect bits error values

Signed-off-by: Norman <[email protected]>

gnovm/stdlibs/io/multi_test.gno

@@ -158,7 +158,7 @@ func TestMultiWriterSingleChainFlatten(t *testing.T) {
 	pc := make([]uintptr, 1000) // 1000 should fit the full stack
 	n := runtime.Callers(0, pc)
 	var myDepth = callDepth(pc[:n])
-	var writeDepth int // will contain the depth from which writerFunc.io.Writer was called
+	var writeDepth int // will contain the depth from which writerFunc.Writer was called
 	var w io.Writer = io.MultiWriter(writerFunc(func(p []byte) (int, error) {
 		n := runtime.Callers(1, pc)
 		writeDepth += callDepth(pc[:n])

gnovm/stdlibs/math/bits/bits.gno

@@ -506,10 +506,10 @@ func Div(hi, lo, y uint) (quo, rem uint) {
 // Div32 panics for y == 0 (division by zero) or y <= hi (quotient overflow).
 func Div32(hi, lo, y uint32) (quo, rem uint32) {
 	if y != 0 && y <= hi {
-		panic(OverflowError)
+		panic(overflowError)
 	}
 	if y == 0 {
-		panic(DivideError)
+		panic(divideError)
 	}
 	z := uint64(hi)<<32 | uint64(lo)
 	quo, rem = uint32(z/uint64(y)), uint32(z%uint64(y))
@@ -522,10 +522,10 @@ func Div32(hi, lo, y uint32) (quo, rem uint32) {
 // Div64 panics for y == 0 (division by zero) or y <= hi (quotient overflow).
 func Div64(hi, lo, y uint64) (quo, rem uint64) {
 	if y == 0 {
-		panic(DivideError)
+		panic(divideError)
 	}
 	if y <= hi {
-		panic(OverflowError)
+		panic(overflowError)
 	}
 
 	// If high part is zero, we can directly return the results.

gnovm/stdlibs/math/bits/bits_errors.gno

@@ -8,5 +8,5 @@ import (
 	"errors"
 )
 
-var OverflowError = errors.New("math/bits: integer overflow")
-var DivideError = errors.New("math/bits: integer divide by zero")
+var overflowError = errors.New("math/bits: integer overflow")
+var divideError = errors.New("math/bits: integer divide by zero")

gnovm/stdlibs/math/bits/export_test.gno

@@ -4,4 +4,9 @@
 
 package bits
 
+// exported for tests
+
 const DeBruijn64 = deBruijn64
+
+var OverflowError = overflowError
+var DivideError = divideError