compiler: restrict return values count for manifest methods

Exported functions from main package shouldn't have more than one return
value.
This commit is contained in:
Anna Shaleva 2022-08-17 12:19:37 +03:00
parent 171364f07f
commit 9b9d72937b
3 changed files with 166 additions and 17 deletions

View file

@ -13,8 +13,13 @@ import (
"golang.org/x/tools/go/packages"
)
// Various exported functions usage errors.
var (
// ErrMissingExportedParamName is returned when exported contract method has unnamed parameter.
var ErrMissingExportedParamName = errors.New("exported method is not allowed to have unnamed parameter")
ErrMissingExportedParamName = errors.New("exported method is not allowed to have unnamed parameter")
// ErrInvalidExportedRetCount is returned when exported contract method has invalid return values count.
ErrInvalidExportedRetCount = errors.New("exported method is not allowed to have more than one return value")
)
var (
// Go language builtin functions.
@ -289,7 +294,7 @@ func (c *codegen) analyzeFuncUsage() funcUsage {
if isMain && n.Name.IsExported() || isInitFunc(n) || isDeployFunc(n) {
diff[name] = true
}
// exported functions are not allowed to have unnamed parameters
// exported functions are not allowed to have unnamed parameters or multiple return values
if isMain && n.Name.IsExported() && n.Recv == nil {
if n.Type.Params.List != nil {
for i, param := range n.Type.Params.List {
@ -305,6 +310,9 @@ func (c *codegen) analyzeFuncUsage() funcUsage {
}
}
}
if retCnt := n.Type.Results.NumFields(); retCnt > 1 {
c.prog.Err = fmt.Errorf("%w: %s/%d return values", ErrInvalidExportedRetCount, n.Name, retCnt)
}
}
nodeCache[name] = declPair{n, c.importMap, pkgPath}
return false // will be processed in the next stage

View file

@ -2,6 +2,7 @@ package compiler_test
import (
"fmt"
"math/big"
"os"
"path/filepath"
"strings"
@ -427,3 +428,147 @@ func TestUnnamedParameterCheck(t *testing.T) {
require.NoError(t, err) // it's OK for exported method to have unnamed params as it won't be included into manifest
})
}
func TestReturnValuesCountCheck(t *testing.T) {
t.Run("void", func(t *testing.T) {
t.Run("exported", func(t *testing.T) {
t.Run("func", func(t *testing.T) {
src := `package testcase
var a int
func Main() {
a = 5
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err)
})
t.Run("method", func(t *testing.T) {
src := `package testcase
type A int
var a int
func (rcv A) Main() {
a = 5
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err)
})
})
t.Run("unexported", func(t *testing.T) {
src := `package testcase
var a int
func main() {
a = 5
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err)
})
})
t.Run("single return", func(t *testing.T) {
t.Run("exported", func(t *testing.T) {
t.Run("func", func(t *testing.T) {
src := `package testcase
var a int
func Main() int {
a = 5
return a
}`
eval(t, src, big.NewInt(5))
})
t.Run("method", func(t *testing.T) {
src := `package testcase
type A int
var a int
func (rcv A) Main() int {
a = 5
return a
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err)
})
})
t.Run("unexported", func(t *testing.T) {
src := `package testcase
var a int
func main() int {
a = 5
return a
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err)
})
})
t.Run("multiple unnamed return vals", func(t *testing.T) {
t.Run("exported", func(t *testing.T) {
t.Run("func", func(t *testing.T) {
src := `package testcase
var a int
func Main() (int, int) {
a = 5
return a, a
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.Error(t, err)
require.ErrorIs(t, err, compiler.ErrInvalidExportedRetCount)
})
t.Run("method", func(t *testing.T) {
src := `package testcase
type A int
var a int
func (rcv A) Main() (int, int) {
a = 5
return a, a
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err) // OK for method to have multiple return values as it won't be included into manifest
})
})
t.Run("unexported", func(t *testing.T) {
src := `package testcase
var a int
func main() (int, int) {
a = 5
return a, a
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err) // OK for unexported function to have multiple return values as it won't be included into manifest
})
})
t.Run("multiple named return vals", func(t *testing.T) {
t.Run("exported", func(t *testing.T) {
t.Run("func", func(t *testing.T) {
src := `package testcase
var a int
func Main() (a int, b int) {
a = 5
b = 2
return
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.Error(t, err)
require.ErrorIs(t, err, compiler.ErrInvalidExportedRetCount)
})
t.Run("method", func(t *testing.T) {
src := `package testcase
type A int
var a int
func (rcv A) Main() (a int, b int) {
a = 5
b = 2
return
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err) // OK for method to have multiple return values as it won't be included into manifest
})
})
t.Run("unexported", func(t *testing.T) {
src := `package testcase
var a int
func main() (a int, b int) {
a = 5
b = 2
return
}`
_, _, err := compiler.CompileWithOptions("test.go", strings.NewReader(src), nil)
require.NoError(t, err) // OK for unexported function to have multiple return values as it won't be included into manifest
})
})
}

View file

@ -4,9 +4,6 @@ import (
"fmt"
"math/big"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestReturnInt64(t *testing.T) {
@ -99,7 +96,11 @@ func TestSingleReturn(t *testing.T) {
func TestNamedReturn(t *testing.T) {
src := `package foo
func Main() (a int, b int) {
func Main() int {
a, b := f()
return a + b
}
func f() (a int, b int) {
a = 1
b = 2
c := 3
@ -107,21 +108,16 @@ func TestNamedReturn(t *testing.T) {
return %s
}`
runCase := func(ret string, result ...interface{}) func(t *testing.T) {
runCase := func(ret string, result *big.Int) func(t *testing.T) {
return func(t *testing.T) {
src := fmt.Sprintf(src, ret)
v := vmAndCompile(t, src)
require.NoError(t, v.Run())
require.Equal(t, len(result), v.Estack().Len())
for i := range result {
assert.EqualValues(t, result[i], v.Estack().Pop().Value())
}
eval(t, src, result)
}
}
t.Run("NormalReturn", runCase("a, b", big.NewInt(1), big.NewInt(2)))
t.Run("EmptyReturn", runCase("", big.NewInt(1), big.NewInt(2)))
t.Run("AnotherVariable", runCase("b, c", big.NewInt(2), big.NewInt(3)))
t.Run("NormalReturn", runCase("a, b", big.NewInt(3)))
t.Run("EmptyReturn", runCase("", big.NewInt(3)))
t.Run("AnotherVariable", runCase("b, c", big.NewInt(5)))
}
func TestTypeAssertReturn(t *testing.T) {