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go/types,types2: add support for unsafe.{String,StringData,SliceData}
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For #53003
Change-Id: Id3125268523fed855ffac20cde6128010e3513f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/423754
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
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@cuiweixie
cuiweixie authored and Robert Griesemer committed Aug 24, 2022
1 parent e4bed41 commit ba5deb4
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Showing 7 changed files with 207 additions and 18 deletions.
70 changes: 66 additions & 4 deletions src/cmd/compile/internal/types2/builtins.go
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Original file line number Diff line number Diff line change
Expand Up @@ -725,8 +725,8 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
return
}

typ, _ := under(x.typ).(*Pointer)
if typ == nil {
ptr, _ := under(x.typ).(*Pointer) // TODO(gri) should this be coreType rather than under?
if ptr == nil {
check.errorf(x, invalidArg+"%s is not a pointer", x)
return
}
Expand All @@ -738,9 +738,71 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
}

x.mode = value
x.typ = NewSlice(typ.base)
x.typ = NewSlice(ptr.base)
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, typ, y.typ))
check.recordBuiltinType(call.Fun, makeSig(x.typ, ptr, y.typ))
}

case _SliceData:
// unsafe.SliceData(slice []T) *T
if !check.allowVersion(check.pkg, 1, 20) {
check.versionErrorf(call.Fun, "go1.20", "unsafe.SliceData")
return
}

slice, _ := under(x.typ).(*Slice) // TODO(gri) should this be coreType rather than under?
if slice == nil {
check.errorf(x, invalidArg+"%s is not a slice", x)
return
}

x.mode = value
x.typ = NewPointer(slice.Elem())
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, slice))
}

case _String:
// unsafe.String(ptr *byte, len IntegerType) string
if !check.allowVersion(check.pkg, 1, 20) {
check.versionErrorf(call.Fun, "go1.20", "unsafe.String")
return
}

check.assignment(x, NewPointer(universeByte), "argument to unsafe.String")
if x.mode == invalid {
return
}

var y operand
arg(&y, 1)
if !check.isValidIndex(&y, "length", false) {
return
}

x.mode = value
x.typ = Typ[String]
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, NewPointer(universeByte), y.typ))
}

case _StringData:
// unsafe.StringData(str string) *byte
if !check.allowVersion(check.pkg, 1, 20) {
check.versionErrorf(call.Fun, "go1.20", "unsafe.StringData")
return
}

str, _ := x.typ.(*Basic)
if str == nil || str.Kind() != String {
check.errorf(x, invalidArg+"%s is not a string", x)
return
}

x.mode = value
x.typ = NewPointer(universeByte)
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, str))
}

case _Assert:
Expand Down
9 changes: 9 additions & 0 deletions src/cmd/compile/internal/types2/builtins_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -129,6 +129,15 @@ var builtinCalls = []struct {
{"Slice", `var p *int; _ = unsafe.Slice(p, 1)`, `func(*int, int) []int`},
{"Slice", `var p *byte; var n uintptr; _ = unsafe.Slice(p, n)`, `func(*byte, uintptr) []byte`},

{"SliceData", "var a []int; _ = unsafe.SliceData(a)", `func([]int) *int`},
{"SliceData", "type sliceType []int; var a sliceType; _ = unsafe.SliceData(a)", `func([]int) *int`},

{"String", `var p *byte; _ = unsafe.String(p, 1)`, `func(*byte, int) string`},
{"String", `type pbyte *byte; var p pbyte; var n uintptr; _ = unsafe.String(p, n)`, `func(*byte, uintptr) string`},

{"StringData", `var s string; _ = unsafe.StringData(s)`, `func(string) *byte`},
{"StringData", `var s = "abc"; _ = unsafe.StringData(s)`, `func(string) *byte`},

{"assert", `assert(true)`, `invalid type`}, // constant
{"assert", `type B bool; const pred B = 1 < 2; assert(pred)`, `invalid type`}, // constant

Expand Down
16 changes: 11 additions & 5 deletions src/cmd/compile/internal/types2/universe.go
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Original file line number Diff line number Diff line change
Expand Up @@ -165,6 +165,9 @@ const (
_Offsetof
_Sizeof
_Slice
_SliceData
_String
_StringData

// testing support
_Assert
Expand Down Expand Up @@ -193,11 +196,14 @@ var predeclaredFuncs = [...]struct {
_Real: {"real", 1, false, expression},
_Recover: {"recover", 0, false, statement},

_Add: {"Add", 2, false, expression},
_Alignof: {"Alignof", 1, false, expression},
_Offsetof: {"Offsetof", 1, false, expression},
_Sizeof: {"Sizeof", 1, false, expression},
_Slice: {"Slice", 2, false, expression},
_Add: {"Add", 2, false, expression},
_Alignof: {"Alignof", 1, false, expression},
_Offsetof: {"Offsetof", 1, false, expression},
_Sizeof: {"Sizeof", 1, false, expression},
_Slice: {"Slice", 2, false, expression},
_SliceData: {"SliceData", 1, false, expression},
_String: {"String", 2, false, expression},
_StringData: {"StringData", 1, false, expression},

_Assert: {"assert", 1, false, statement},
_Trace: {"trace", 0, true, statement},
Expand Down
70 changes: 66 additions & 4 deletions src/go/types/builtins.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -734,8 +734,8 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
return
}

typ, _ := under(x.typ).(*Pointer)
if typ == nil {
ptr, _ := under(x.typ).(*Pointer) // TODO(gri) should this be coreType rather than under?
if ptr == nil {
check.invalidArg(x, _InvalidUnsafeSlice, "%s is not a pointer", x)
return
}
Expand All @@ -747,9 +747,71 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
}

x.mode = value
x.typ = NewSlice(typ.base)
x.typ = NewSlice(ptr.base)
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, typ, y.typ))
check.recordBuiltinType(call.Fun, makeSig(x.typ, ptr, y.typ))
}

case _SliceData:
// unsafe.SliceData(str string) *byte
if !check.allowVersion(check.pkg, 1, 20) {
check.errorf(call.Fun, _InvalidUnsafeSliceData, "unsafe.SliceData requires go1.20 or later")
return
}

slice, ok := under(x.typ).(*Slice)
if !ok {
check.invalidArg(x, _InvalidUnsafeSliceData, "%s is not a slice", x)
return
}
x.mode = value
x.typ = NewPointer(slice.Elem())
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, slice))
}

case _String:
// unsafe.String(ptr *byte, len IntegerType) string
if !check.allowVersion(check.pkg, 1, 20) {
check.errorf(call.Fun, _InvalidUnsafeString, "unsafe.String requires go1.20 or later")
return
}

check.assignment(x, NewPointer(universeByte), "argument to unsafe.String")
if x.mode == invalid {
check.invalidArg(x, _InvalidUnsafeString, "%s is not a *byte", x)
return
}

var y operand
arg(&y, 1)
if !check.isValidIndex(&y, _InvalidUnsafeString, "length", false) {
return
}

x.mode = value
x.typ = Typ[String]
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, NewPointer(universeByte), y.typ))
}

case _StringData:
// unsafe.StringData(str string) *byte
if !check.allowVersion(check.pkg, 1, 20) {
check.errorf(call.Fun, _InvalidUnsafeStringData, "unsafe.StringData requires go1.20 or later")
return
}

str, _ := x.typ.(*Basic)
if str == nil || str.kind != String {
check.invalidArg(x, _InvalidUnsafeStringData, "%s is not a string", x)
return
}

x.mode = value
x.typ = NewPointer(universeByte)
if check.Types != nil {
check.recordBuiltinType(call.Fun, makeSig(x.typ, str))
}

case _Assert:
Expand Down
9 changes: 9 additions & 0 deletions src/go/types/builtins_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -130,6 +130,15 @@ var builtinCalls = []struct {
{"Slice", `var p *int; _ = unsafe.Slice(p, 1)`, `func(*int, int) []int`},
{"Slice", `var p *byte; var n uintptr; _ = unsafe.Slice(p, n)`, `func(*byte, uintptr) []byte`},

{"SliceData", "var a []int; _ = unsafe.SliceData(a)", `func([]int) *int`},
{"SliceData", "type sliceType []int; var a sliceType; _ = unsafe.SliceData(a)", `func([]int) *int`},

{"String", `var p *byte; _ = unsafe.String(p, 1)`, `func(*byte, int) string`},
{"String", `type pbyte *byte; var p pbyte; var n uintptr; _ = unsafe.String(p, n)`, `func(*byte, uintptr) string`},

{"StringData", `var s string; _ = unsafe.StringData(s)`, `func(string) *byte`},
{"StringData", `var s = "abc"; _ = unsafe.StringData(s)`, `func(string) *byte`},

{"assert", `assert(true)`, `invalid type`}, // constant
{"assert", `type B bool; const pred B = 1 < 2; assert(pred)`, `invalid type`}, // constant

Expand Down
35 changes: 35 additions & 0 deletions src/go/types/errorcodes.go
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Original file line number Diff line number Diff line change
Expand Up @@ -1389,4 +1389,39 @@ const (
// Example:
// type T[P any] struct{ *P }
_MisplacedTypeParam

// _InvalidUnsafeSliceData occurs when unsafe.SliceData called with type
// is not slice
//
// Example:
// import "unsafe"
//
// var x int
// var _ = unsafe.SliceData(x)
_InvalidUnsafeSliceData

// _InvalidUnsafeString occurs when unsafe.String is called with a
// pointer argument that is not of pointer type or a length argument
// that is not of integer type, negative, or out of bounds.
//
// Example:
// import "unsafe"
//
// var b [10]byte
// var _ = unsafe.String(&b[0], -1)
_InvalidUnsafeString

// _InvalidUnsafeStringData
//
// Example:
// import "unsafe"
//
// var x int
// var _ = unsafe.StringData(x)
//
// Example:
// import "unsafe"
//
// var _ = unsafe.StringData("abc")
_InvalidUnsafeStringData
)
16 changes: 11 additions & 5 deletions src/go/types/universe.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -166,6 +166,9 @@ const (
_Offsetof
_Sizeof
_Slice
_SliceData
_String
_StringData

// testing support
_Assert
Expand Down Expand Up @@ -194,11 +197,14 @@ var predeclaredFuncs = [...]struct {
_Real: {"real", 1, false, expression},
_Recover: {"recover", 0, false, statement},

_Add: {"Add", 2, false, expression},
_Alignof: {"Alignof", 1, false, expression},
_Offsetof: {"Offsetof", 1, false, expression},
_Sizeof: {"Sizeof", 1, false, expression},
_Slice: {"Slice", 2, false, expression},
_Add: {"Add", 2, false, expression},
_Alignof: {"Alignof", 1, false, expression},
_Offsetof: {"Offsetof", 1, false, expression},
_Sizeof: {"Sizeof", 1, false, expression},
_Slice: {"Slice", 2, false, expression},
_SliceData: {"SliceData", 1, false, expression},
_String: {"String", 2, false, expression},
_StringData: {"StringData", 1, false, expression},

_Assert: {"assert", 1, false, statement},
_Trace: {"trace", 0, true, statement},
Expand Down

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