diff options
Diffstat (limited to 'src/go/types')
| -rw-r--r-- | src/go/types/api_test.go | 12 | ||||
| -rw-r--r-- | src/go/types/check_test.go | 7 | ||||
| -rw-r--r-- | src/go/types/expr.go | 34 |
3 files changed, 44 insertions, 9 deletions
diff --git a/src/go/types/api_test.go b/src/go/types/api_test.go index b2d532c4c8..f138af5fbf 100644 --- a/src/go/types/api_test.go +++ b/src/go/types/api_test.go @@ -322,6 +322,18 @@ func TestTypesInfo(t *testing.T) { `[][]struct{}`, }, + // issue 47243 + {`package issue47243_a; var x int32; var _ = x << 3`, `3`, `untyped int`}, + {`package issue47243_b; var x int32; var _ = x << 3.`, `3.`, `uint`}, // issue 47410: should be untyped float + {`package issue47243_c; var x int32; var _ = 1 << x`, `1 << x`, `int`}, + {`package issue47243_d; var x int32; var _ = 1 << x`, `1`, `int`}, + {`package issue47243_e; var x int32; var _ = 1 << 2`, `1`, `untyped int`}, + {`package issue47243_f; var x int32; var _ = 1 << 2`, `2`, `untyped int`}, + {`package issue47243_g; var x int32; var _ = int(1) << 2`, `2`, `untyped int`}, + {`package issue47243_h; var x int32; var _ = 1 << (2 << x)`, `1`, `int`}, + {`package issue47243_i; var x int32; var _ = 1 << (2 << x)`, `(2 << x)`, `untyped int`}, + {`package issue47243_j; var x int32; var _ = 1 << (2 << x)`, `2`, `untyped int`}, + // tests for broken code that doesn't parse or type-check {broken + `x0; func _() { var x struct {f string}; x.f := 0 }`, `x.f`, `string`}, {broken + `x1; func _() { var z string; type x struct {f string}; y := &x{q: z}}`, `z`, `string`}, diff --git a/src/go/types/check_test.go b/src/go/types/check_test.go index 692004facf..8c8452c9c6 100644 --- a/src/go/types/check_test.go +++ b/src/go/types/check_test.go @@ -354,6 +354,13 @@ func TestIndexRepresentability(t *testing.T) { testFiles(t, &StdSizes{4, 4}, []string{"index.go"}, [][]byte{[]byte(src)}, false, nil) } +func TestIssue47243_TypedRHS(t *testing.T) { + // The RHS of the shift expression below overflows uint on 32bit platforms, + // but this is OK as it is explicitly typed. + const src = "package issue47243\n\nvar a uint64; var _ = a << uint64(4294967296)" // uint64(1<<32) + testFiles(t, &StdSizes{4, 4}, []string{"p.go"}, [][]byte{[]byte(src)}, false, nil) +} + func TestCheck(t *testing.T) { DefPredeclaredTestFuncs(); testDirFiles(t, "testdata/check", false) } func TestExamples(t *testing.T) { testDirFiles(t, "testdata/examples", false) } func TestFixedbugs(t *testing.T) { testDirFiles(t, "testdata/fixedbugs", false) } diff --git a/src/go/types/expr.go b/src/go/types/expr.go index b55f51185f..c9a55aa871 100644 --- a/src/go/types/expr.go +++ b/src/go/types/expr.go @@ -795,32 +795,48 @@ func (check *Checker) shift(x, y *operand, e ast.Expr, op token.Token) { // spec: "The right operand in a shift expression must have integer type // or be an untyped constant representable by a value of type uint." - // Provide a good error message for negative shift counts. + // Check that constants are representable by uint, but do not convert them + // (see also issue #47243). if y.mode == constant_ { + // Provide a good error message for negative shift counts. yval := constant.ToInt(y.val) // consider -1, 1.0, but not -1.1 if yval.Kind() == constant.Int && constant.Sign(yval) < 0 { check.invalidOp(y, _InvalidShiftCount, "negative shift count %s", y) x.mode = invalid return } + + if isUntyped(y.typ) { + // Caution: Check for representability here, rather than in the switch + // below, because isInteger includes untyped integers (was bug #43697). + check.representable(y, Typ[Uint]) + if y.mode == invalid { + x.mode = invalid + return + } + } } - // Caution: Check for isUntyped first because isInteger includes untyped - // integers (was bug #43697). - if isUntyped(y.typ) { + // Check that RHS is otherwise at least of integer type. + switch { + case isInteger(y.typ): + if !isUnsigned(y.typ) && !check.allowVersion(check.pkg, 1, 13) { + check.invalidOp(y, _InvalidShiftCount, "signed shift count %s requires go1.13 or later", y) + x.mode = invalid + return + } + case isUntyped(y.typ): + // This is incorrect, but preserves pre-existing behavior. + // See also bug #47410. check.convertUntyped(y, Typ[Uint]) if y.mode == invalid { x.mode = invalid return } - } else if !isInteger(y.typ) { + default: check.invalidOp(y, _InvalidShiftCount, "shift count %s must be integer", y) x.mode = invalid return - } else if !isUnsigned(y.typ) && !check.allowVersion(check.pkg, 1, 13) { - check.invalidOp(y, _InvalidShiftCount, "signed shift count %s requires go1.13 or later", y) - x.mode = invalid - return } if x.mode == constant_ { |