diff options
| -rw-r--r-- | tools/go_marshal/gomarshal/BUILD | 3 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator.go | 17 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces.go | 665 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go | 183 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go | 229 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_struct.go | 450 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_tests.go | 2 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/util.go | 41 | ||||
| -rw-r--r-- | tools/go_marshal/test/test.go | 5 |
9 files changed, 915 insertions, 680 deletions
diff --git a/tools/go_marshal/gomarshal/BUILD b/tools/go_marshal/gomarshal/BUILD index b5d5a4487..44cb33ae4 100644 --- a/tools/go_marshal/gomarshal/BUILD +++ b/tools/go_marshal/gomarshal/BUILD @@ -7,6 +7,9 @@ go_library( srcs = [ "generator.go", "generator_interfaces.go", + "generator_interfaces_array_newtype.go", + "generator_interfaces_primitive_newtype.go", + "generator_interfaces_struct.go", "generator_tests.go", "util.go", ], diff --git a/tools/go_marshal/gomarshal/generator.go b/tools/go_marshal/gomarshal/generator.go index d365a1f3c..729489de5 100644 --- a/tools/go_marshal/gomarshal/generator.go +++ b/tools/go_marshal/gomarshal/generator.go @@ -235,6 +235,10 @@ func (g *Generator) collectMarshallableTypes(a *ast.File, f *token.FileSet) []*a debugfAt(f.Position(t.Pos()), "Collected marshallable newtype on primitive %s.\n", t.Name.Name) types = append(types, t) continue + case *ast.ArrayType: // Newtype on array. + debugfAt(f.Position(t.Pos()), "Collected marshallable newtype on array %s.\n", t.Name.Name) + types = append(types, t) + continue } // A user specifically requested marshalling on this type, but we // don't support it. @@ -281,17 +285,20 @@ func (g *Generator) generateOne(t *ast.TypeSpec, fset *token.FileSet) *interface i := newInterfaceGenerator(t, fset) switch ty := t.Type.(type) { case *ast.StructType: - i.validateStruct() - i.emitMarshallableForStruct() - return i + i.validateStruct(t, ty) + i.emitMarshallableForStruct(ty) case *ast.Ident: i.validatePrimitiveNewtype(ty) - i.emitMarshallableForPrimitiveNewtype() - return i + i.emitMarshallableForPrimitiveNewtype(ty) + case *ast.ArrayType: + i.validateArrayNewtype(t.Name, ty) + // After validate, we can safely call arrayLen. + i.emitMarshallableForArrayNewtype(t.Name, ty.Elt.(*ast.Ident), arrayLen(ty)) default: // This should've been filtered out by collectMarshallabeTypes. panic(fmt.Sprintf("Unexpected type %+v", ty)) } + return i } // generateOneTestSuite generates a test suite for the automatically generated diff --git a/tools/go_marshal/gomarshal/generator_interfaces.go b/tools/go_marshal/gomarshal/generator_interfaces.go index ea1af998e..8babf61d2 100644 --- a/tools/go_marshal/gomarshal/generator_interfaces.go +++ b/tools/go_marshal/gomarshal/generator_interfaces.go @@ -15,10 +15,8 @@ package gomarshal import ( - "fmt" "go/ast" "go/token" - "strings" ) // interfaceGenerator generates marshalling interfaces for a single type. @@ -81,18 +79,6 @@ func (g *interfaceGenerator) recordPotentiallyNonPackedField(fieldName string) { g.as[fieldName] = struct{}{} } -func (g *interfaceGenerator) forEachField(fn func(f *ast.Field)) { - // This is guaranteed to succeed because g.t is always a struct. - st := g.t.Type.(*ast.StructType) - for _, field := range st.Fields.List { - fn(field) - } -} - -func (g *interfaceGenerator) fieldAccessor(n *ast.Ident) string { - return fmt.Sprintf("%s.%s", g.r, n.Name) -} - // abortAt aborts the go_marshal tool with the given error message, with a // reference position to the input source. Same as abortAt, but uses g to // resolve p to position. @@ -100,71 +86,6 @@ func (g *interfaceGenerator) abortAt(p token.Pos, msg string) { abortAt(g.f.Position(p), msg) } -func (g *interfaceGenerator) validatePrimitiveNewtype(t *ast.Ident) { - switch t.Name { - case "int8", "uint8", "byte", "int16", "uint16", "int32", "uint32", "int64", "uint64": - // These are the only primitive types we're allow. Below, we provide - // suggestions for some disallowed types and reject them, then attempt - // to marshal any remaining types by invoking the marshal.Marshallable - // interface on them. If these types don't actually implement - // marshal.Marshallable, compilation of the generated code will fail - // with an appropriate error message. - return - case "int": - g.abortAt(t.Pos(), "Type 'int' has ambiguous width, use int32 or int64") - case "uint": - g.abortAt(t.Pos(), "Type 'uint' has ambiguous width, use uint32 or uint64") - case "string": - g.abortAt(t.Pos(), "Type 'string' is dynamically-sized and cannot be marshalled, use a fixed size byte array '[...]byte' instead") - default: - debugfAt(g.f.Position(t.Pos()), fmt.Sprintf("Found derived type '%s', will attempt dispatch via marshal.Marshallable.\n", t.Name)) - } -} - -// validateStruct ensures the type we're working with can be marshalled. These -// checks are done ahead of time and in one place so we can make assumptions -// later. -func (g *interfaceGenerator) validateStruct() { - g.forEachField(func(f *ast.Field) { - if len(f.Names) == 0 { - g.abortAt(f.Pos(), "Cannot marshal structs with embedded fields, give the field a name; use '_' for anonymous fields such as padding fields") - } - }) - - g.forEachField(func(f *ast.Field) { - fieldDispatcher{ - primitive: func(_, t *ast.Ident) { - g.validatePrimitiveNewtype(t) - }, - selector: func(_, _, _ *ast.Ident) { - // No validation to perform on selector fields. However this - // callback must still be provided. - }, - array: func(n, _ *ast.Ident, len int) { - a := f.Type.(*ast.ArrayType) - if a.Len == nil { - g.abortAt(f.Pos(), fmt.Sprintf("Dynamically sized slice '%s' cannot be marshalled, arrays must be statically sized", n.Name)) - } - - if _, ok := a.Len.(*ast.BasicLit); !ok { - g.abortAt(a.Len.Pos(), fmt.Sprintf("Array size must be a literal, don's use consts or expressions")) - } - - if _, ok := a.Elt.(*ast.Ident); !ok { - g.abortAt(a.Elt.Pos(), fmt.Sprintf("Marshalling not supported for arrays with %s elements, array elements must be primitive types", kindString(a.Elt))) - } - - if len <= 0 { - g.abortAt(a.Len.Pos(), fmt.Sprintf("Marshalling not supported for zero length arrays, why does an ABI struct have one?")) - } - }, - unhandled: func(_ *ast.Ident) { - g.abortAt(f.Pos(), fmt.Sprintf("Marshalling not supported for %s fields", kindString(f.Type))) - }, - }.dispatch(f) - }) -} - // scalarSize returns the size of type identified by t. If t isn't a primitive // type, the size isn't known at code generation time, and must be resolved via // the marshal.Marshallable interface. @@ -191,8 +112,8 @@ func (g *interfaceGenerator) shiftDynamic(bufVar, name string) { g.emit("%s = %s[%s.SizeBytes():]\n", bufVar, bufVar, name) } -// marshalStructFieldScalar writes a single scalar field from a struct to a byte slice. -func (g *interfaceGenerator) marshalStructFieldScalar(accessor, typ, bufVar string) { +// marshalScalar writes a single scalar to a byte slice. +func (g *interfaceGenerator) marshalScalar(accessor, typ, bufVar string) { switch typ { case "int8", "uint8", "byte": g.emit("%s[0] = byte(%s)\n", bufVar, accessor) @@ -215,9 +136,8 @@ func (g *interfaceGenerator) marshalStructFieldScalar(accessor, typ, bufVar stri } } -// unmarshalStructFieldScalar reads a single scalar field from a struct, from a -// byte slice. -func (g *interfaceGenerator) unmarshalStructFieldScalar(accessor, typ, bufVar string) { +// unmarshalScalar reads a single scalar from a byte slice. +func (g *interfaceGenerator) unmarshalScalar(accessor, typ, bufVar string) { switch typ { case "byte": g.emit("%s = %s[0]\n", accessor, bufVar) @@ -243,580 +163,3 @@ func (g *interfaceGenerator) unmarshalStructFieldScalar(accessor, typ, bufVar st g.recordPotentiallyNonPackedField(accessor) } } - -// marshalPrimitiveScalar writes a single primitive variable to a byte slice. -func (g *interfaceGenerator) marshalPrimitiveScalar(accessor, typ, bufVar string) { - switch typ { - case "int8", "uint8", "byte": - g.emit("%s[0] = byte(*%s)\n", bufVar, accessor) - case "int16", "uint16": - g.recordUsedImport("usermem") - g.emit("usermem.ByteOrder.PutUint16(%s[:2], uint16(*%s))\n", bufVar, accessor) - case "int32", "uint32": - g.recordUsedImport("usermem") - g.emit("usermem.ByteOrder.PutUint32(%s[:4], uint32(*%s))\n", bufVar, accessor) - case "int64", "uint64": - g.recordUsedImport("usermem") - g.emit("usermem.ByteOrder.PutUint64(%s[:8], uint64(*%s))\n", bufVar, accessor) - default: - g.emit("inner := (*%s)(%s)\n", typ, accessor) - g.emit("inner.MarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) - } -} - -// unmarshalPrimitiveScalar read a single primitive variable from a byte slice. -func (g *interfaceGenerator) unmarshalPrimitiveScalar(accessor, typ, bufVar, typeCast string) { - switch typ { - case "byte": - g.emit("*%s = %s(%s[0])\n", accessor, typeCast, bufVar) - case "int8", "uint8": - g.emit("*%s = %s(%s(%s[0]))\n", accessor, typeCast, typ, bufVar) - case "int16", "uint16": - g.recordUsedImport("usermem") - g.emit("*%s = %s(%s(usermem.ByteOrder.Uint16(%s[:2])))\n", accessor, typeCast, typ, bufVar) - case "int32", "uint32": - g.recordUsedImport("usermem") - g.emit("*%s = %s(%s(usermem.ByteOrder.Uint32(%s[:4])))\n", accessor, typeCast, typ, bufVar) - - case "int64", "uint64": - g.recordUsedImport("usermem") - g.emit("*%s = %s(%s(usermem.ByteOrder.Uint64(%s[:8])))\n", accessor, typeCast, typ, bufVar) - default: - g.emit("inner := (*%s)(%s)\n", typ, accessor) - g.emit("inner.UnmarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) - } -} - -// areFieldsPackedExpression returns a go expression checking whether g.t's fields are -// packed. Returns "", false if g.t has no fields that may be potentially -// packed, otherwise returns <clause>, true, where <clause> is an expression -// like "t.a.Packed() && t.b.Packed() && t.c.Packed()". -func (g *interfaceGenerator) areFieldsPackedExpression() (string, bool) { - if len(g.as) == 0 { - return "", false - } - - cs := make([]string, 0, len(g.as)) - for accessor, _ := range g.as { - cs = append(cs, fmt.Sprintf("%s.Packed()", accessor)) - } - return strings.Join(cs, " && "), true -} - -func (g *interfaceGenerator) emitMarshallableForStruct() { - // Is g.t a packed struct without consideing field types? - thisPacked := true - g.forEachField(func(f *ast.Field) { - if f.Tag != nil { - if f.Tag.Value == "`marshal:\"unaligned\"`" { - if thisPacked { - debugfAt(g.f.Position(g.t.Pos()), - fmt.Sprintf("Marking type '%s' as not packed due to tag `marshal:\"unaligned\"`.\n", g.t.Name)) - thisPacked = false - } - } - } - }) - - g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") - g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) - g.inIndent(func() { - primitiveSize := 0 - var dynamicSizeTerms []string - - g.forEachField(fieldDispatcher{ - primitive: func(n, t *ast.Ident) { - if size, dynamic := g.scalarSize(t); !dynamic { - primitiveSize += size - } else { - g.recordUsedMarshallable(t.Name) - dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", t.Name)) - } - }, - selector: func(n, tX, tSel *ast.Ident) { - tName := fmt.Sprintf("%s.%s", tX.Name, tSel.Name) - g.recordUsedImport(tX.Name) - g.recordUsedMarshallable(tName) - dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", tName)) - }, - array: func(n, t *ast.Ident, len int) { - if len < 1 { - // Zero-length arrays should've been rejected by validate(). - panic("unreachable") - } - if size, dynamic := g.scalarSize(t); !dynamic { - primitiveSize += size * len - } else { - g.recordUsedMarshallable(t.Name) - dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()*%d", t.Name, len)) - } - }, - }.dispatch) - g.emit("return %d", primitiveSize) - if len(dynamicSizeTerms) > 0 { - g.incIndent() - } - { - for _, d := range dynamicSizeTerms { - g.emitNoIndent(" +\n") - g.emit(d) - } - } - if len(dynamicSizeTerms) > 0 { - g.decIndent() - } - }) - g.emit("\n}\n\n") - - g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") - g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.forEachField(fieldDispatcher{ - primitive: func(n, t *ast.Ident) { - if n.Name == "_" { - g.emit("// Padding: dst[:sizeof(%s)] ~= %s(0)\n", t.Name, t.Name) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("dst", len) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can referece here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("dst = dst[(*%s)(nil).SizeBytes():]\n", t.Name) - } - return - } - g.marshalStructFieldScalar(g.fieldAccessor(n), t.Name, "dst") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.marshalStructFieldScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "dst") - }, - array: func(n, t *ast.Ident, size int) { - if n.Name == "_" { - g.emit("// Padding: dst[:sizeof(%s)*%d] ~= [%d]%s{0}\n", t.Name, size, size, t.Name) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("dst", len*size) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can reference here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("dst = dst[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) - } - return - } - - g.emit("for idx := 0; idx < %d; idx++ {\n", size) - g.inIndent(func() { - g.marshalStructFieldScalar(fmt.Sprintf("%s[idx]", g.fieldAccessor(n)), t.Name, "dst") - }) - g.emit("}\n") - }, - }.dispatch) - }) - g.emit("}\n\n") - - g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") - g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.forEachField(fieldDispatcher{ - primitive: func(n, t *ast.Ident) { - if n.Name == "_" { - g.emit("// Padding: var _ %s ~= src[:sizeof(%s)]\n", t.Name, t.Name) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("src", len) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can reference here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("src = src[(*%s)(nil).SizeBytes():]\n", t.Name) - g.recordPotentiallyNonPackedField(fmt.Sprintf("(*%s)(nil)", t.Name)) - } - return - } - g.unmarshalStructFieldScalar(g.fieldAccessor(n), t.Name, "src") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.unmarshalStructFieldScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "src") - }, - array: func(n, t *ast.Ident, size int) { - if n.Name == "_" { - g.emit("// Padding: ~ copy([%d]%s(%s), src[:sizeof(%s)*%d])\n", size, t.Name, g.fieldAccessor(n), t.Name, size) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("src", len*size) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can referece here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("src = src[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) - } - return - } - - g.emit("for idx := 0; idx < %d; idx++ {\n", size) - g.inIndent(func() { - g.unmarshalStructFieldScalar(fmt.Sprintf("%s[idx]", g.fieldAccessor(n)), t.Name, "src") - }) - g.emit("}\n") - }, - }.dispatch) - }) - g.emit("}\n\n") - - g.emit("// Packed implements marshal.Marshallable.Packed.\n") - g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) - g.inIndent(func() { - expr, fieldsMaybePacked := g.areFieldsPackedExpression() - switch { - case !thisPacked: - g.emit("return false\n") - case fieldsMaybePacked: - g.emit("return %s\n", expr) - default: - g.emit("return true\n") - - } - }) - g.emit("}\n\n") - - g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") - g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - if thisPacked { - g.recordUsedImport("safecopy") - g.recordUsedImport("unsafe") - if cond, ok := g.areFieldsPackedExpression(); ok { - g.emit("if %s {\n", cond) - g.inIndent(func() { - g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) - }) - g.emit("} else {\n") - g.inIndent(func() { - g.emit("%s.MarshalBytes(dst)\n", g.r) - }) - g.emit("}\n") - } else { - g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) - } - } else { - g.emit("// Type %s doesn't have a packed layout in memory, fallback to MarshalBytes.\n", g.typeName()) - g.emit("%s.MarshalBytes(dst)\n", g.r) - } - }) - g.emit("}\n\n") - - g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") - g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - if thisPacked { - g.recordUsedImport("safecopy") - g.recordUsedImport("unsafe") - if cond, ok := g.areFieldsPackedExpression(); ok { - g.emit("if %s {\n", cond) - g.inIndent(func() { - g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) - }) - g.emit("} else {\n") - g.inIndent(func() { - g.emit("%s.UnmarshalBytes(src)\n", g.r) - }) - g.emit("}\n") - } else { - g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) - } - } else { - g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) - g.emit("%s.UnmarshalBytes(src)\n", g.r) - } - }) - g.emit("}\n\n") - - g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") - g.recordUsedImport("marshal") - g.recordUsedImport("usermem") - g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) - g.inIndent(func() { - fallback := func() { - g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) - g.emit("buf := task.CopyScratchBuffer(%s.SizeBytes())\n", g.r) - g.emit("%s.MarshalBytes(buf)\n", g.r) - g.emit("_, err := task.CopyOutBytes(addr, buf)\n") - g.emit("return err\n") - } - if thisPacked { - g.recordUsedImport("reflect") - g.recordUsedImport("runtime") - g.recordUsedImport("unsafe") - if cond, ok := g.areFieldsPackedExpression(); ok { - g.emit("if !%s {\n", cond) - g.inIndent(fallback) - g.emit("}\n\n") - } - // Fast serialization. - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyOutBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyOutBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return err\n") - } else { - fallback() - } - }) - g.emit("}\n\n") - - g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") - g.recordUsedImport("marshal") - g.recordUsedImport("usermem") - g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) - g.inIndent(func() { - fallback := func() { - g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) - g.emit("buf := task.CopyScratchBuffer(%s.SizeBytes())\n", g.r) - g.emit("_, err := task.CopyInBytes(addr, buf)\n") - g.emit("if err != nil {\n") - g.inIndent(func() { - g.emit("return err\n") - }) - g.emit("}\n") - - g.emit("%s.UnmarshalBytes(buf)\n", g.r) - g.emit("return nil\n") - } - if thisPacked { - g.recordUsedImport("reflect") - g.recordUsedImport("runtime") - g.recordUsedImport("unsafe") - if cond, ok := g.areFieldsPackedExpression(); ok { - g.emit("if !%s {\n", cond) - g.inIndent(fallback) - g.emit("}\n\n") - } - // Fast deserialization. - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyInBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyInBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return err\n") - } else { - fallback() - } - }) - g.emit("}\n\n") - - g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") - g.recordUsedImport("io") - g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) - g.inIndent(func() { - fallback := func() { - g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) - g.emit("buf := make([]byte, %s.SizeBytes())\n", g.r) - g.emit("%s.MarshalBytes(buf)\n", g.r) - g.emit("n, err := w.Write(buf)\n") - g.emit("return int64(n), err\n") - } - if thisPacked { - g.recordUsedImport("reflect") - g.recordUsedImport("runtime") - g.recordUsedImport("unsafe") - if cond, ok := g.areFieldsPackedExpression(); ok { - g.emit("if !%s {\n", cond) - g.inIndent(fallback) - g.emit("}\n\n") - } - // Fast serialization. - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("len, err := w.Write(buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the Write.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return int64(len), err\n") - } else { - fallback() - } - }) - g.emit("}\n\n") -} - -// emitMarshallableForPrimitiveNewtype outputs code to implement the -// marshal.Marshallable interface for a newtype on a primitive. Primitive -// newtypes are always packed, so we can omit the various fallbacks required for -// non-packed structs. -func (g *interfaceGenerator) emitMarshallableForPrimitiveNewtype() { - g.recordUsedImport("io") - g.recordUsedImport("marshal") - g.recordUsedImport("reflect") - g.recordUsedImport("runtime") - g.recordUsedImport("safecopy") - g.recordUsedImport("unsafe") - g.recordUsedImport("usermem") - - nt := g.t.Type.(*ast.Ident) - - g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") - g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) - g.inIndent(func() { - if size, dynamic := g.scalarSize(nt); !dynamic { - g.emit("return %d\n", size) - } else { - g.emit("return (*%s)(nil).SizeBytes()\n", nt.Name) - } - }) - g.emit("}\n\n") - - g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") - g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.marshalPrimitiveScalar(g.r, nt.Name, "dst") - }) - g.emit("}\n\n") - - g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") - g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.unmarshalPrimitiveScalar(g.r, nt.Name, "src", g.typeName()) - }) - g.emit("}\n\n") - - g.emit("// Packed implements marshal.Marshallable.Packed.\n") - g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) - g.inIndent(func() { - g.emit("// Scalar newtypes are always packed.\n") - g.emit("return true\n") - }) - g.emit("}\n\n") - - g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") - g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) - }) - g.emit("}\n\n") - - g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") - g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) - }) - g.emit("}\n\n") - - g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") - g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) - g.inIndent(func() { - // Fast serialization. - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyOutBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyOutBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return err\n") - }) - g.emit("}\n\n") - - g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") - g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) - g.inIndent(func() { - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyInBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyInBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return err\n") - }) - g.emit("}\n\n") - - g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") - g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("len, err := w.Write(buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the Write.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return int64(len), err\n") - - }) - g.emit("}\n\n") - -} diff --git a/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go b/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go new file mode 100644 index 000000000..da36d9305 --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go @@ -0,0 +1,183 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// This file contains the bits of the code generator specific to marshalling +// newtypes on arrays. + +package gomarshal + +import ( + "fmt" + "go/ast" +) + +func (g *interfaceGenerator) validateArrayNewtype(n *ast.Ident, a *ast.ArrayType) { + if a.Len == nil { + g.abortAt(a.Pos(), fmt.Sprintf("Dynamically sized slice '%s' cannot be marshalled, arrays must be statically sized", n.Name)) + } + + if _, ok := a.Len.(*ast.BasicLit); !ok { + g.abortAt(a.Len.Pos(), fmt.Sprintf("Array size must be a literal, don't use consts or expressions")) + } + + if _, ok := a.Elt.(*ast.Ident); !ok { + g.abortAt(a.Elt.Pos(), fmt.Sprintf("Marshalling not supported for arrays with %s elements, array elements must be primitive types", kindString(a.Elt))) + } + + if arrayLen(a) <= 0 { + g.abortAt(a.Len.Pos(), fmt.Sprintf("Marshalling not supported for zero length arrays, why does an ABI struct have one?")) + } +} + +func (g *interfaceGenerator) emitMarshallableForArrayNewtype(n, elt *ast.Ident, len int) { + g.recordUsedImport("io") + g.recordUsedImport("marshal") + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + g.recordUsedImport("usermem") + + g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") + g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) + g.inIndent(func() { + if size, dynamic := g.scalarSize(elt); !dynamic { + g.emit("return %d\n", size*len) + } else { + g.emit("return (*%s)(nil).SizeBytes() * %d\n", n.Name, len) + } + }) + g.emit("}\n\n") + + g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") + g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("for idx := 0; idx < %d; idx++ {\n", len) + g.inIndent(func() { + g.marshalScalar(fmt.Sprintf("%s[idx]", g.r), elt.Name, "dst") + }) + g.emit("}\n") + }) + g.emit("}\n\n") + + g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") + g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("for idx := 0; idx < %d; idx++ {\n", len) + g.inIndent(func() { + g.unmarshalScalar(fmt.Sprintf("%s[idx]", g.r), elt.Name, "src") + }) + g.emit("}\n") + }) + g.emit("}\n\n") + + g.emit("// Packed implements marshal.Marshallable.Packed.\n") + g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Array newtypes are always packed.\n") + g.emit("return true\n") + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") + g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") + g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") + g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) + g.inIndent(func() { + // Fast serialization. + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("_, err := task.CopyOutBytes(addr, buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the CopyOutBytes.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return err\n") + }) + g.emit("}\n\n") + + g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") + g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("_, err := task.CopyInBytes(addr, buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the CopyInBytes.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return err\n") + }) + g.emit("}\n\n") + + g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") + g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("len, err := w.Write(buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the Write.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return int64(len), err\n") + + }) + g.emit("}\n\n") +} diff --git a/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go b/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go new file mode 100644 index 000000000..159397825 --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go @@ -0,0 +1,229 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// This file contains the bits of the code generator specific to marshalling +// newtypes on primitives. + +package gomarshal + +import ( + "fmt" + "go/ast" +) + +// marshalPrimitiveScalar writes a single primitive variable to a byte +// slice. +func (g *interfaceGenerator) marshalPrimitiveScalar(accessor, typ, bufVar string) { + switch typ { + case "int8", "uint8", "byte": + g.emit("%s[0] = byte(*%s)\n", bufVar, accessor) + case "int16", "uint16": + g.recordUsedImport("usermem") + g.emit("usermem.ByteOrder.PutUint16(%s[:2], uint16(*%s))\n", bufVar, accessor) + case "int32", "uint32": + g.recordUsedImport("usermem") + g.emit("usermem.ByteOrder.PutUint32(%s[:4], uint32(*%s))\n", bufVar, accessor) + case "int64", "uint64": + g.recordUsedImport("usermem") + g.emit("usermem.ByteOrder.PutUint64(%s[:8], uint64(*%s))\n", bufVar, accessor) + default: + g.emit("// Explicilty cast to the underlying type before dispatching to\n") + g.emit("// MarshalBytes, so we don't recursively call %s.MarshalBytes\n", accessor) + g.emit("inner := (*%s)(%s)\n", typ, accessor) + g.emit("inner.MarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) + } +} + +// unmarshalPrimitiveScalar read a single primitive variable from a byte slice. +func (g *interfaceGenerator) unmarshalPrimitiveScalar(accessor, typ, bufVar, typeCast string) { + switch typ { + case "byte": + g.emit("*%s = %s(%s[0])\n", accessor, typeCast, bufVar) + case "int8", "uint8": + g.emit("*%s = %s(%s(%s[0]))\n", accessor, typeCast, typ, bufVar) + case "int16", "uint16": + g.recordUsedImport("usermem") + g.emit("*%s = %s(%s(usermem.ByteOrder.Uint16(%s[:2])))\n", accessor, typeCast, typ, bufVar) + case "int32", "uint32": + g.recordUsedImport("usermem") + g.emit("*%s = %s(%s(usermem.ByteOrder.Uint32(%s[:4])))\n", accessor, typeCast, typ, bufVar) + case "int64", "uint64": + g.recordUsedImport("usermem") + g.emit("*%s = %s(%s(usermem.ByteOrder.Uint64(%s[:8])))\n", accessor, typeCast, typ, bufVar) + default: + g.emit("// Explicilty cast to the underlying type before dispatching to\n") + g.emit("// UnmarshalBytes, so we don't recursively call %s.UnmarshalBytes\n", accessor) + g.emit("inner := (*%s)(%s)\n", typ, accessor) + g.emit("inner.UnmarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) + } +} + +func (g *interfaceGenerator) validatePrimitiveNewtype(t *ast.Ident) { + switch t.Name { + case "int8", "uint8", "byte", "int16", "uint16", "int32", "uint32", "int64", "uint64": + // These are the only primitive types we're allow. Below, we provide + // suggestions for some disallowed types and reject them, then attempt + // to marshal any remaining types by invoking the marshal.Marshallable + // interface on them. If these types don't actually implement + // marshal.Marshallable, compilation of the generated code will fail + // with an appropriate error message. + return + case "int": + g.abortAt(t.Pos(), "Type 'int' has ambiguous width, use int32 or int64") + case "uint": + g.abortAt(t.Pos(), "Type 'uint' has ambiguous width, use uint32 or uint64") + case "string": + g.abortAt(t.Pos(), "Type 'string' is dynamically-sized and cannot be marshalled, use a fixed size byte array '[...]byte' instead") + default: + debugfAt(g.f.Position(t.Pos()), fmt.Sprintf("Found derived type '%s', will attempt dispatch via marshal.Marshallable.\n", t.Name)) + } +} + +// emitMarshallableForPrimitiveNewtype outputs code to implement the +// marshal.Marshallable interface for a newtype on a primitive. Primitive +// newtypes are always packed, so we can omit the various fallbacks required for +// non-packed structs. +func (g *interfaceGenerator) emitMarshallableForPrimitiveNewtype(nt *ast.Ident) { + g.recordUsedImport("io") + g.recordUsedImport("marshal") + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + g.recordUsedImport("usermem") + + g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") + g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) + g.inIndent(func() { + if size, dynamic := g.scalarSize(nt); !dynamic { + g.emit("return %d\n", size) + } else { + g.emit("return (*%s)(nil).SizeBytes()\n", nt.Name) + } + }) + g.emit("}\n\n") + + g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") + g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.marshalPrimitiveScalar(g.r, nt.Name, "dst") + }) + g.emit("}\n\n") + + g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") + g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.unmarshalPrimitiveScalar(g.r, nt.Name, "src", g.typeName()) + }) + g.emit("}\n\n") + + g.emit("// Packed implements marshal.Marshallable.Packed.\n") + g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Scalar newtypes are always packed.\n") + g.emit("return true\n") + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") + g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") + g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") + g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) + g.inIndent(func() { + // Fast serialization. + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("_, err := task.CopyOutBytes(addr, buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the CopyOutBytes.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return err\n") + }) + g.emit("}\n\n") + + g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") + g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("_, err := task.CopyInBytes(addr, buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the CopyInBytes.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return err\n") + }) + g.emit("}\n\n") + + g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") + g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("len, err := w.Write(buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the Write.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return int64(len), err\n") + + }) + g.emit("}\n\n") +} diff --git a/tools/go_marshal/gomarshal/generator_interfaces_struct.go b/tools/go_marshal/gomarshal/generator_interfaces_struct.go new file mode 100644 index 000000000..e66a38b2e --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_struct.go @@ -0,0 +1,450 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// This file contains the bits of the code generator specific to marshalling +// structs. + +package gomarshal + +import ( + "fmt" + "go/ast" + "strings" +) + +func (g *interfaceGenerator) fieldAccessor(n *ast.Ident) string { + return fmt.Sprintf("%s.%s", g.r, n.Name) +} + +// areFieldsPackedExpression returns a go expression checking whether g.t's fields are +// packed. Returns "", false if g.t has no fields that may be potentially +// packed, otherwise returns <clause>, true, where <clause> is an expression +// like "t.a.Packed() && t.b.Packed() && t.c.Packed()". +func (g *interfaceGenerator) areFieldsPackedExpression() (string, bool) { + if len(g.as) == 0 { + return "", false + } + + cs := make([]string, 0, len(g.as)) + for accessor, _ := range g.as { + cs = append(cs, fmt.Sprintf("%s.Packed()", accessor)) + } + return strings.Join(cs, " && "), true +} + +// validateStruct ensures the type we're working with can be marshalled. These +// checks are done ahead of time and in one place so we can make assumptions +// later. +func (g *interfaceGenerator) validateStruct(ts *ast.TypeSpec, st *ast.StructType) { + forEachStructField(st, func(f *ast.Field) { + if len(f.Names) == 0 { + g.abortAt(f.Pos(), "Cannot marshal structs with embedded fields, give the field a name; use '_' for anonymous fields such as padding fields") + } + }) + + forEachStructField(st, func(f *ast.Field) { + fieldDispatcher{ + primitive: func(_, t *ast.Ident) { + g.validatePrimitiveNewtype(t) + }, + selector: func(_, _, _ *ast.Ident) { + // No validation to perform on selector fields. However this + // callback must still be provided. + }, + array: func(n, _ *ast.Ident, len int) { + g.validateArrayNewtype(n, f.Type.(*ast.ArrayType)) + }, + unhandled: func(_ *ast.Ident) { + g.abortAt(f.Pos(), fmt.Sprintf("Marshalling not supported for %s fields", kindString(f.Type))) + }, + }.dispatch(f) + }) +} + +func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { + // Is g.t a packed struct without consideing field types? + thisPacked := true + forEachStructField(st, func(f *ast.Field) { + if f.Tag != nil { + if f.Tag.Value == "`marshal:\"unaligned\"`" { + if thisPacked { + debugfAt(g.f.Position(g.t.Pos()), + fmt.Sprintf("Marking type '%s' as not packed due to tag `marshal:\"unaligned\"`.\n", g.t.Name)) + thisPacked = false + } + } + } + }) + + g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") + g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) + g.inIndent(func() { + primitiveSize := 0 + var dynamicSizeTerms []string + + forEachStructField(st, fieldDispatcher{ + primitive: func(n, t *ast.Ident) { + if size, dynamic := g.scalarSize(t); !dynamic { + primitiveSize += size + } else { + g.recordUsedMarshallable(t.Name) + dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", t.Name)) + } + }, + selector: func(n, tX, tSel *ast.Ident) { + tName := fmt.Sprintf("%s.%s", tX.Name, tSel.Name) + g.recordUsedImport(tX.Name) + g.recordUsedMarshallable(tName) + dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", tName)) + }, + array: func(n, t *ast.Ident, len int) { + if len < 1 { + // Zero-length arrays should've been rejected by validate(). + panic("unreachable") + } + if size, dynamic := g.scalarSize(t); !dynamic { + primitiveSize += size * len + } else { + g.recordUsedMarshallable(t.Name) + dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()*%d", t.Name, len)) + } + }, + }.dispatch) + g.emit("return %d", primitiveSize) + if len(dynamicSizeTerms) > 0 { + g.incIndent() + } + { + for _, d := range dynamicSizeTerms { + g.emitNoIndent(" +\n") + g.emit(d) + } + } + if len(dynamicSizeTerms) > 0 { + g.decIndent() + } + }) + g.emit("\n}\n\n") + + g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") + g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + forEachStructField(st, fieldDispatcher{ + primitive: func(n, t *ast.Ident) { + if n.Name == "_" { + g.emit("// Padding: dst[:sizeof(%s)] ~= %s(0)\n", t.Name, t.Name) + if len, dynamic := g.scalarSize(t); !dynamic { + g.shift("dst", len) + } else { + // We can't use shiftDynamic here because we don't have + // an instance of the dynamic type we can referece here + // (since the version in this struct is anonymous). Use + // a typed nil pointer to call SizeBytes() instead. + g.emit("dst = dst[(*%s)(nil).SizeBytes():]\n", t.Name) + } + return + } + g.marshalScalar(g.fieldAccessor(n), t.Name, "dst") + }, + selector: func(n, tX, tSel *ast.Ident) { + g.marshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "dst") + }, + array: func(n, t *ast.Ident, size int) { + if n.Name == "_" { + g.emit("// Padding: dst[:sizeof(%s)*%d] ~= [%d]%s{0}\n", t.Name, size, size, t.Name) + if len, dynamic := g.scalarSize(t); !dynamic { + g.shift("dst", len*size) + } else { + // We can't use shiftDynamic here because we don't have + // an instance of the dynamic type we can reference here + // (since the version in this struct is anonymous). Use + // a typed nil pointer to call SizeBytes() instead. + g.emit("dst = dst[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) + } + return + } + + g.emit("for idx := 0; idx < %d; idx++ {\n", size) + g.inIndent(func() { + g.marshalScalar(fmt.Sprintf("%s[idx]", g.fieldAccessor(n)), t.Name, "dst") + }) + g.emit("}\n") + }, + }.dispatch) + }) + g.emit("}\n\n") + + g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") + g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + forEachStructField(st, fieldDispatcher{ + primitive: func(n, t *ast.Ident) { + if n.Name == "_" { + g.emit("// Padding: var _ %s ~= src[:sizeof(%s)]\n", t.Name, t.Name) + if len, dynamic := g.scalarSize(t); !dynamic { + g.shift("src", len) + } else { + // We can't use shiftDynamic here because we don't have + // an instance of the dynamic type we can reference here + // (since the version in this struct is anonymous). Use + // a typed nil pointer to call SizeBytes() instead. + g.emit("src = src[(*%s)(nil).SizeBytes():]\n", t.Name) + g.recordPotentiallyNonPackedField(fmt.Sprintf("(*%s)(nil)", t.Name)) + } + return + } + g.unmarshalScalar(g.fieldAccessor(n), t.Name, "src") + }, + selector: func(n, tX, tSel *ast.Ident) { + g.unmarshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "src") + }, + array: func(n, t *ast.Ident, size int) { + if n.Name == "_" { + g.emit("// Padding: ~ copy([%d]%s(%s), src[:sizeof(%s)*%d])\n", size, t.Name, g.fieldAccessor(n), t.Name, size) + if len, dynamic := g.scalarSize(t); !dynamic { + g.shift("src", len*size) + } else { + // We can't use shiftDynamic here because we don't have + // an instance of the dynamic type we can referece here + // (since the version in this struct is anonymous). Use + // a typed nil pointer to call SizeBytes() instead. + g.emit("src = src[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) + } + return + } + + g.emit("for idx := 0; idx < %d; idx++ {\n", size) + g.inIndent(func() { + g.unmarshalScalar(fmt.Sprintf("%s[idx]", g.fieldAccessor(n)), t.Name, "src") + }) + g.emit("}\n") + }, + }.dispatch) + }) + g.emit("}\n\n") + + g.emit("// Packed implements marshal.Marshallable.Packed.\n") + g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) + g.inIndent(func() { + expr, fieldsMaybePacked := g.areFieldsPackedExpression() + switch { + case !thisPacked: + g.emit("return false\n") + case fieldsMaybePacked: + g.emit("return %s\n", expr) + default: + g.emit("return true\n") + + } + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") + g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + if thisPacked { + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if %s {\n", cond) + g.inIndent(func() { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + }) + g.emit("} else {\n") + g.inIndent(func() { + g.emit("%s.MarshalBytes(dst)\n", g.r) + }) + g.emit("}\n") + } else { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + } + } else { + g.emit("// Type %s doesn't have a packed layout in memory, fallback to MarshalBytes.\n", g.typeName()) + g.emit("%s.MarshalBytes(dst)\n", g.r) + } + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") + g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + if thisPacked { + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if %s {\n", cond) + g.inIndent(func() { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + }) + g.emit("} else {\n") + g.inIndent(func() { + g.emit("%s.UnmarshalBytes(src)\n", g.r) + }) + g.emit("}\n") + } else { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + } + } else { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) + g.emit("%s.UnmarshalBytes(src)\n", g.r) + } + }) + g.emit("}\n\n") + + g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") + g.recordUsedImport("marshal") + g.recordUsedImport("usermem") + g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) + g.emit("buf := task.CopyScratchBuffer(%s.SizeBytes())\n", g.r) + g.emit("%s.MarshalBytes(buf)\n", g.r) + g.emit("_, err := task.CopyOutBytes(addr, buf)\n") + g.emit("return err\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !%s {\n", cond) + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast serialization. + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("_, err := task.CopyOutBytes(addr, buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the CopyOutBytes.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") + g.recordUsedImport("marshal") + g.recordUsedImport("usermem") + g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) + g.emit("buf := task.CopyScratchBuffer(%s.SizeBytes())\n", g.r) + g.emit("_, err := task.CopyInBytes(addr, buf)\n") + g.emit("if err != nil {\n") + g.inIndent(func() { + g.emit("return err\n") + }) + g.emit("}\n") + + g.emit("%s.UnmarshalBytes(buf)\n", g.r) + g.emit("return nil\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !%s {\n", cond) + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast deserialization. + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("_, err := task.CopyInBytes(addr, buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the CopyInBytes.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") + g.recordUsedImport("io") + g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) + g.emit("buf := make([]byte, %s.SizeBytes())\n", g.r) + g.emit("%s.MarshalBytes(buf)\n", g.r) + g.emit("n, err := w.Write(buf)\n") + g.emit("return int64(n), err\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !%s {\n", cond) + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast serialization. + g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) + g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) + g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") + g.emit("ptr := unsafe.Pointer(%s)\n", g.r) + g.emit("val := uintptr(ptr)\n") + g.emit("val = val^0\n\n") + + g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) + g.emit("var buf []byte\n") + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") + g.emit("hdr.Data = val\n") + g.emit("hdr.Len = %s.SizeBytes()\n", g.r) + g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) + + g.emit("len, err := w.Write(buf)\n") + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) + g.emit("// must live until after the Write.\n") + g.emit("runtime.KeepAlive(%s)\n", g.r) + g.emit("return int64(len), err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") +} diff --git a/tools/go_marshal/gomarshal/generator_tests.go b/tools/go_marshal/gomarshal/generator_tests.go index 8ba47eb67..fd992e44a 100644 --- a/tools/go_marshal/gomarshal/generator_tests.go +++ b/tools/go_marshal/gomarshal/generator_tests.go @@ -164,7 +164,7 @@ func (g *testGenerator) emitTestSizeBytesOnTypedNilPtr() { g.emit("if sizeFromTypedNilPtr != sizeFromConcrete {\n") g.inIndent(func() { - g.emit("t.Fatalf(\"SizeBytes() on typed nil pointer (%v) doesn't match size returned by a concrete object (%v).\\n\", sizeFromTypedNilPtr, sizeFromConcrete)") + g.emit("t.Fatalf(\"SizeBytes() on typed nil pointer (%v) doesn't match size returned by a concrete object (%v).\\n\", sizeFromTypedNilPtr, sizeFromConcrete)\n") }) g.emit("}\n") }) diff --git a/tools/go_marshal/gomarshal/util.go b/tools/go_marshal/gomarshal/util.go index e2bca4e7c..a0936e013 100644 --- a/tools/go_marshal/gomarshal/util.go +++ b/tools/go_marshal/gomarshal/util.go @@ -64,6 +64,12 @@ func kindString(e ast.Expr) string { } } +func forEachStructField(st *ast.StructType, fn func(f *ast.Field)) { + for _, field := range st.Fields.List { + fn(field) + } +} + // fieldDispatcher is a collection of callbacks for handling different types of // fields in a struct declaration. type fieldDispatcher struct { @@ -73,6 +79,25 @@ type fieldDispatcher struct { unhandled func(n *ast.Ident) } +// Precondition: a must have a literal for the array length. Consts and +// expressions are not allowed as array lengths, and should be rejected by the +// caller. +func arrayLen(a *ast.ArrayType) int { + if a.Len == nil { + // Probably a slice? Must be handled by caller. + panic("Nil array length in array type") + } + lenLit, ok := a.Len.(*ast.BasicLit) + if !ok { + panic("Array has non-literal for length") + } + len, err := strconv.Atoi(lenLit.Value) + if err != nil { + panic(fmt.Sprintf("Failed to parse array length '%s' as number: %v", lenLit.Value, err)) + } + return len +} + // Precondition: All dispatch callbacks that will be invoked must be // provided. Embedded fields are not allowed, len(f.Names) >= 1. func (fd fieldDispatcher) dispatch(f *ast.Field) { @@ -96,22 +121,12 @@ func (fd fieldDispatcher) dispatch(f *ast.Field) { case *ast.SelectorExpr: fd.selector(name, v.X.(*ast.Ident), v.Sel) case *ast.ArrayType: - len := 0 - if v.Len != nil { - // Non-literal array length is handled by generatorInterfaces.validate(). - if lenLit, ok := v.Len.(*ast.BasicLit); ok { - var err error - len, err = strconv.Atoi(lenLit.Value) - if err != nil { - panic(err) - } - } - } switch t := v.Elt.(type) { case *ast.Ident: - fd.array(name, t, len) + fd.array(name, t, arrayLen(v)) default: - fd.array(name, nil, len) + // Should be handled with a better error message during validate. + panic(fmt.Sprintf("Array element type is of unsupported kind. Expected *ast.Ident, got %v", t)) } default: fd.unhandled(name) diff --git a/tools/go_marshal/test/test.go b/tools/go_marshal/test/test.go index 93229dedb..c829db6da 100644 --- a/tools/go_marshal/test/test.go +++ b/tools/go_marshal/test/test.go @@ -104,6 +104,11 @@ type Stat struct { _ [3]int64 } +// InetAddr is an example marshallable newtype on an array. +// +// +marshal +type InetAddr [4]byte + // SignalSet is an example marshallable newtype on a primitive. // // +marshal |